Short Notes in Plastic Surgery

October 10, 2018

70. Treatment Strategies in Cases of Pan-plexal Avulsion Injuries of the Brachial Plexus

Filed under: Chapter 70,Uncategorized — ravinthatte @ 11:17 am

70. Treatment Strategies in Cases of Pan-plexal Avulsion Injuries of the Brachial Plexus

(In cases where roots (C5 to T1) are not available for repair at the site).

Though a global or pan-plexal palsy can result from laceration of post-ganglionic nerve roots the present chapter deals only with a palsy where all roots are avulsed from the spinal cord.

The aims and objects of the reconstructive surgeon under the above condition are as follows.

  1. Restore the function of abduction and external rotation at the shoulder
  2. Restore the ability to flex the elbow
  3. Restore extension at the elbow
  4. Restore the flexion and extension at the wrist
  5. To achieve at least mass flexion of the fingers for a grip
  6. Restore extension of the fingers
  7. Get the thumb to move in a position away from the palm to achieve a grip
  8. Restore sensations to the hand.

There are basically two methods to achieve these objectives:

  1. restoration by extraplexal neurotisation of affected nerves for restoring functions of muscles as well as regaining sensations
  2. a combination of extraplexal neurotisation as well as importing free functioning muscles (FFMT) to restore action of muscles.
  3. The nerve reconstruction effort can be done in one stage the results are then observed over some months and the residual deficiencies can be then corrected at a later stage.
  4. The reconstruction is planned in stages to begin with and as the stages are accomplished information on the success or failures of the stages will influence later strategies.

It is generally accepted that the scope and availability of tissue for revitalising all the muscular actions mentioned above is limited. For example, at the wrist an arthrodesis in a position of function will spare FFMTs which then can be used for actions involving fingers. In the case of the thumb though a restoration of active opposition for a grip is ideal, recourse might be taken to get the thumb in a better position by a static procedure (not by an arthrodesis which is usually avoided) but by re-routing a tendon (a tenodesis procedure). At the elbow because the arm falls by its own weight and gets extended passively more attention is paid to flexion at the elbow in a dynamic fashion. Because the actions of the arm are performed with the help of at least some abduction at the shoulder the restoration of active abduction at the shoulder is considered crucial by most surgeons and constitutes the foundation of the rest of the reconstructive procedures distally. There might be cases where as a result of paralysis of muscles around the shoulder particularly in late cases the shoulder might tend to sub luxate in which case a procedure to fix the shoulder in a slightly abducted position of function might become necessary.

In order to compile this chapter, the help of three leading surgeons in India who do considerable work on patients with injuries to the brachial plexus was sought and they were invited to narrate their strategies. Their names are Dr. Anil Bhatia an orthopaedic surgeon from Pune whose practice is restricted to patients with injuries to the brachial plexus, Dr. Mukund Thatte a plastic surgeon and a leading hand surgeon who practices in Mumbai and Dr. Venugopal Purushothaman a leading plastic hand and brachial plexus surgeon from Chennai. All three hail from India.

The material in this chapter does not include procedures to restore sensations to the limb nor does it include secondary procedures which may be employed to correct any residual problems following the primary treatment. These subjects are to be covered in later chapters.

The strategy of Dr. Purushothaman is narrated below with the help of diagrams. The strategy involves restoration of nerve functions by extra plexal nerve sources and does not involve FFM transfers certainly not primarily. In his method the extra-plexal neurotization is done in a single stage with the help of two teams who work simultaneously. The various manoeuvres are narrated below followed by diagrams.

  1. Spinal accessory to the suprascapular nerve. This is one procedure that appears to be common to all the contributors to this chapter. The suprascapular nerve is the first branch of the upper trunk and supplies the supraspinatus muscle a prime abductor of the shoulder, as well as the Infraspinatus, which is an external rotator.
  2. Contra lateral (opposite) C7 root is bridged with a nerve graft (usually sural nerve) and joined to the axillary nerve arising from the posterior cord of the brachial plexus (C5 C6) which supplies the deltoid muscle. This procedure too is done to restore abduction at the shoulder
  3. The same C7 root is also joined with a nerve graft same as above to the nerve to the biceps a branch of musculocutaneous nerve (C5 C6).
  4. A vascularised ulnar nerve graft from the same side is rotated and its distal end is joined also to the contralateral C7 root and its proximal end is joined to the whole of the median nerve (flexors of the wrist and fingers) and is also joined to all motor branches of the radial nerve which supply extensors of the wrist and fingers. In addition, one funiculus of this graft is used to supply the nerve to the brachialis a branch of the musculocutaneous nerve.
  5. The third intercostal motor nerve is used to supply the nerve to the pectoralis muscle the lateral pectoral nerve (C 5 6 7).
  6. The fourth and the fifth motor intercostal nerves are joined to the nerve to the triceps branch of the radial nerve.
  7. The sixth intercostal motor nerve is joined to the nerve to the serratus anterior or the long thoracic nerve.
  8. In the next stage, the thumb is positioned to allow opposition by a static opponensplasty. The tendon used is the flexor carpi ulnaris (FCU) which is detached from its insertion extended in length with a tendon graft such as by a piece of palmaris longus to go around the metacarpal of the thumb and brought in an opposable position.
  9. The flexor digitorum profundi muscles are tagged to each other for a mass action enabling flexion of all fingers.

This completes the re-neurotization. 1, 2, 5, 7 will look after the shoulder 3, 6 will enable elbow movements 4 will look after the movements of the hand and fingers. The diagrams that follow describe in nutshell the procedures undertaken by Dr. Purushothaman.

Slide1

Slide2

Slide3

Slide4

Slide5

Dr. Anil Bhatia performs the reconstruction in one stage. He joins the spinal accessory nerve of the same side to the suprascapular nerve (abduction of the shoulder). He also uses the Phrenic nerve of the same side to join to the posterior division of the lower trunk for extension of the elbow. He then mobilizes the brachial plexus on the affected side in the following manner.

  1. All three upper middle and lower trunk are completely dissected.
  2. The delto-pectoral grove is opened and all the cords with the musculocutaneous nerve are isolated.
  3. The medial cord is traced behind the clavicle till its roots C8 T1 roots and is delivered under the clavicle.
  4. The posterior division of the lower trunk is now visible.
  5. That division is split off the lower trunk.
  6. The opposite C7 is then isolated and traced distally as far as possible till the converging elements of the upper and middle trunks.
  7. The branch to the serratus anterior is divided to allow for its transfer across the neck.
  8. The C7 contralateral root is then transferred across the neck, sometimes behind the oesophagus or via the carotid sheath and brought as much as possible on the affected side or at least near the midline near the medial border of the sternomastoid close to the supra-sternal notch.
  9. The mobilization of the anterior division of the lower trunk on the affected side allows it to reach near the supra-sternal notch where the contralateral C7 root now lies on adduction of the arm.
  10. If this approximation is difficult the humerus is shortened to facilitate upward and medial movement of the anterior division of the lower trunk.
  11. The opposite C7 root is now joined to the anterior division of the lower trunk (flexion of fingers).
  12. In addition the medial cutaneous nerve of the fore arm already divided at its origin to facilitate the mobilisation of the anterior division of the medial cord is used as a conduit to reinnervate the musculocutaneous nerve via the opposite C7 root. This can be supplemented by an additional conduit of a sural nerve graft between the C7 root and the musculocutaneous nerve for flexion of the elbow by way of the biceps.

In summary: In one procedure the abduction of the shoulder the flexion and the extension of the elbow the flexion and extension of the fingers is provided for.

The figures below conform to what Dr. Bhatia does in one stage for a global avulsion palsy.

Slide6

Slide7

Slide8

Slide9

Slide10

Slide11

Slide12

Slide13

Slide14

Slide15

Dr. Mukund Thatte performs the reconstructive procedures in four stages after confirming that no reconstruction is possible at the level of the roots.

First stage

  1. Spinal accessory nerve to the suprascapular nerve for abduction at the shoulder.
  2. Opposite hemi C7 root (posterior half) to the lateral cord for reinnervation of the biceps and pectoralis major plus sensation in the Median territory via lateral root of the Median which is a terminal branch of the lateral cord.

Second stage

  1. Free functional muscle transfer (FFMT) of Gracilis muscle across the volar surface of the elbow. The transferred muscle is innervated by the intercostal nerves and vascularised through the thoracodorsal vessels. The muscle is sutured to the tendons of the flexor digitorum profundus as well as flexor pollicis longus.
  2. One intercostal nerve is used to innervate the triceps muscle.
  3. Sensory branches of Intercostals joined to Ulnar.

Stage three

  1. Wrist fusion if there is no recovery of extensors

Stage four

  1. Opponensplasty to improve function in the hand from the recovered flexor pollicis longus from the earlier neurotization

Slide16

Slide17

Slide18

Slide19

Slide20

Slide21

Slide22

Advertisements

April 3, 2018

68. Compressive Neuropathy of the Radial nerve

Filed under: Chapter 68,Uncategorized — ravinthatte @ 10:26 am

68. Compressive Neuropathy of the Radial nerve

The compiler of these short notes thanks Dr. Anil Bhat, Professor and Head, Department of Orthopaedics, Kasturba Medical College and Manipal Academy of Higher Education, for scrutinising the manuscript, general guidance and some illustrations. He has done notable work on compressive neuropathies in the arm. The cadaveric dissections were performed by Dr. Saumil Shah and Dr. Chirag Bhansali both senior residents in the department of plastic surgery at the Lokmanya Tilak municipal hospital and college Mumbai under the supervision of Dr. Maksud Devle a professor in the same department. Dr. Natarajan the head of the department of anatomy kindly allowed these dissections.

1.   The radial nerve receives contributions from the posterior cord of the brachial plexus from which it arises but also from all three trunks superior middle and inferior of the brachial plexus and therefore its root value is C5 6 7 8 as well as T1. It gives branches to all three heads of the triceps muscle as it emerges from the lower triangular space (Fig. 1).

Slide1

The nerve is accompanied at its exit from this space by the brachial artery. It then passes behind the humerus along its spiral groove and can be damaged at this site by fractures in the middle third of the humerus (Fig. 2 and 3).

Slide2

Slide3

2.   In some of these cases of fractures of the humerus, the nerve can also be damaged during surgery when the fractures of the humerus are reduced and fixed by appliances. Rarely the radial nerve may be affected by a tardy palsy when the fracture comes to unite even though the nerve is in continuity. The spiral groove is also the area where the nerve can get compressed by a sharp edge on which the arm rests when the arm is extended and abducted during deep sleep or in a state of inebriation. In popular parlance, this is called the Saturday night palsy where all extensors of the wrist and fingers are paralysed. The condition usually recovers spontaneously though in the interim the hand needs to be splinted, at least at the wrist (in extension) to allow actions by the flexors.

3.   From here on the nerve pierces the lateral intermuscular septum to enter the anterior compartment and lies in a furrowed space between the brachialis on the medial side and the brachioradialis and then the extensor carpi radialis on the lateral side. It is in front of the lateral condyle of the humerus that it divides into the superficial and the deep branch also called the posterior interosseous nerve (PIN) and it is these two nerves that may suffer a compressive neuropathy which is the subject of this chapter. The superficial branch is sensory and is called radial sensory nerve (RSN). The PIN is purely motor. Please see figures 2 and 3 above.

4.   The RSN travels along the radial border of the forearm below the brachioradialis. Half way down in the middle of the forearm it becomes subcutaneous between the brachioradialis and the extensor carpi radialis brevis by piercing the deep fascia and it is at this site that pain along the nerve can be elicited by tapping to produce exaggeration of symptoms of its compressive neuropathy (Fig. 4 and 5 below). It divides into two main branches 5 centimetres proximal to the radial styloid one of which supplies the dorsal and the radial surface of the thumb and the other called the major dorsal branch supplies the dorso-ulnar surface of the thumb as well as the dorsal radial aspect of the index finger. Another branch supplies sensations to the dorso-radial surface of the index and the dorso ulnar surface of the long finger.

Slide4

Slide5

Actions involving strong pronation and simultaneous ulnar deviation puts this nerve on maximum stretch and any profession involving such repeated action predisposes to a neuropathy of the nerve. Repeated use of a heavy screw driver is an example. It is worth noting that this action results in approximation of the brachioradialis and the extensor carpi radialis brevis which might compress the nerve as it emerges from under the deep fascia leading to repeated ischemia. In modern times a variety of wrist and forearm bands are used in many a sport as also in activities such as lifting weights in the gymnasia. This together with tight wrist watch belts or heavy bangles that Indian women wear and may cause friction and contribute to the compression.

The condition produces pain or paraesthesia along the nerve and its sensory distribution and can rarely lead to loss of sensations. The pain is exacerbated when the nerve is tapped as well as when the forearm is pronated and flexed ulnar wards at the wrist.

Slide6
Fritz de Quervains

One branch of this nerve is in close approximation to the first extensor compartment of the wrist (Fig. 4) which is known to undergo an inflammatory pathological constriction leading to pain and poor gliding of the long extensor and abductor of the thumb. The condition is named after Fritz de Quervains (1868-1940) who was mainly known for his study of thyroid disease but also described an inflammatory condition of the tendons in the first extensor compartment.

A neuropathy of the radial sensory nerve might coexist with de Quervains disease because the obstructed first compartment and the consequent inflammation may temporarily affect the nerve. The diagnosis is made by tapping over the first extensor compartment when pain usually does not spread along the distribution of the nerve if the condition is restricted to the first extensor compartment. An improper release of the first compartment without identifying and securing the nerve can however lead to consequences such as a painful neuritis or anaesthesia in the distribution of the nerve.

The entrapment of the radial sensory nerve can be treated surgically by an incision not more than 3 centimetres in length placed vertically over the course of the nerve at about the junction of the upper two thirds and the lower one third of the flexor aspect of the forearm (Fig. 6).

Slide7

In view of the small size of the nerve some form of magnification is advised. The first step is to identify the musculotendinous junction of the brachioradialis muscle. Then by retracting the skin posterio-laterally the extensor carpi radialis brevis tendon can be visualised. The wound is undermined proximally and then distally and the fascia between the two muscles is identified by inserting a small right-angled retractor on either side. The nerve may be seen emerging in the lower end of the incision. If not the fascia between the two muscles is incised and the two muscles are retracted in their proximal part and in the bed created by this retraction the nerve can be visualised. The incision in the fascia is then extended distally and then proximally for about 10 centimetres and this will suffice to completely decompress the nerve. Occasionally a part of the brachio radialis muscle might have to be resected along its vertical direction. Only the skin and subcutaneous tissue are closed leaving the deep fascia open. A supporting dressing across the wrist joint with a thin plaster slab is employed to give post-operative rest to the part.

5.   The posterior interosseous nerve (P.I.N) is the larger of the two branches of the radial neve and arises in front of the lateral epicondyle of the humerus but unlike the sensory branch enters the posterior compartment of the forearm between the two heads of the supinator (humeral and ulnar) muscle (Fig. 12 and 13 see below). But prior to that it may encounter a fibro-tendinous arcade originating from the radio humeral joint which merges with fascia covering the supinator muscle (Fig. 7 and 8). This structure is named after Fritz Frohse (1871-1916, German anatomist).

Slide8

Slide9

6.   After emerging from the supinator muscle the nerve divides into a superficial and a deep branch. The superficial branch supplies the extensor carpi ulnaris the extensor digiti communis and the extensor digiti quinti muscles. The deep branch supplies both the long and short extensor of the thumb and its long abductor as well as the additional extensor to the index finger (indexus proprius). Prior to crossing the elbow the radial nerve supplies the brachialis the anconeus and the brachioradialis. The P.I.N. passes through a tunnel like structure near the elbow. The tunnel’s floor is formed by the capsule of the radio-ulnar joint. The tunnel’s medial wall is formed mainly by the tendon of the biceps muscle and also the brachialis. It’s lateral wall is formed by the brachio-radialis and the long and short extensors of the wrist. Of these the brachioradialis crosses across the tunnel over the nerve from the lateral to the anterior side partly forming the tunnel’s roof. The arcade of Frohse mentioned earlier in the preceding paragraph is also adjacent to this tunnel but its location might vary. The nerve can get compressed in this tunnel because of fibrous bands in between the two heads of the supinator muscle. Gray’s anatomy states that the nerve can also get compressed here by the sharp edge of the extensor carpi radialis brevis, ECRB (Fig. 9) or a leash of vessels from the radial recurrent artery which supply the brachioradialis muscle as well as the extensor carpi radialis longus muscle ECRL (Fig. 10).

slide101.jpg

The leash of vessels is probably named after Henri A.K. Henry also wrote the well known book the Extensile exposures of the extremities (Fig. 11).

Slide11

Slide12

Slide13

7.   The main symptom of the radial tunnel syndrome is pain and paralytic effects of the muscles that the P.I.N supplies are rare except when the compression is severe or in post-traumatic cases where the nerve might be damaged within the radial tunnel. In non-traumatic cases the pain is classically produced by pressure over an area between the brachioradialis and the extensor carpi radialis longus. Pain is also caused when pressure is applied over the supinator when the forearm is being supinated. To rule out any pressure on the undivided radial nerve pressure is applied above the elbow between the tendon of the biceps and the origin of the brachioradialis just above the elbow when pain will not be felt. The diagnosis of the radial tunnel syndrome is mainly clinical and electrodiagnostic methods are not useful. Infiltration with local anaesthetic agents sequentially can help locate the area of entrapment.

Surgery to treat the radial tunnel / P.I.N.syndrome is performed by an incision along the posterior border of the brachioradialis muscle marked by asking the patient to flex the elbow in the mid prone position against resistance. The incision about 10 centimetres will expose the extensor carpi radialis longus (E.C.R.L.) on the lateral side and the brachioradialis on the medial side.

A very thin nerve the posterior cutaneous nerve of the fore arm can be identified here and should be saved. The area between the two muscles is occupied by a fascia which is incised sharply by retracting the two muscles. Further retraction will reveal vessels straddling the two muscles which are cauterized. A plane is developed between the two muscles above and below by blunt dissection with a finger. In the area thus created can then be seen both the superficial and deep (P.I.N.) branches of the radial nerve. The P.I.N. here can be seen entering the supinator muscle. The humeral superficial head of the supinator is then stripped off or incised over the humerus to release it and take away the compression of the P.I.N. The detached head of the muscle is then held and any fibrous bands between it and its deep origin are then cut away. At this stage a finger can be introduced in the proximal part of the incision at the level of the elbow and burrowed higher to take away any constricting elements around the main trunk of the radial nerve. Some surgeons as a form of caution detach the origin of the long radial extensor of the wrist (E.C.R.L.) from the lateral epicondyle just in case the condition was only one of lateral epicondylitis (Fig. 14-18 below).

Slide14

Slide15

Slide16

All above photographs courtesy Dr. Anil Bhat.

February 19, 2018

67. Compressive Neuropathy of the Ulnar Nerve

Filed under: Chapter 67,Uncategorized — ravinthatte @ 4:32 am

67. Compressive neuropathy of the ulnar nerve

The compiler of these short notes acknowledges the help of Drs. Mukund Thatte from Mumbai and Rajendra Nehete from Nashik in India both plastic surgeons with special interest in surgery of the hand in writing this chapter. The cadaveric dissections were performed by Professor Maksud Devale assisted by Sumit Hadgaonkar as well as Neeraj Bhaban both senior residents; all from the department of plastic surgery at the Lokmanya Tilak municipal medical college and hospital in Mumbai. Professor Natrajan the head of the department of anatomy of the above institutions was kind enough to allow the dissections.

  1. The ulnar nerve is a mixed nerve and is a terminal branch of the medial cord borrowing its fibres from the C8 and T1 nerve roots.

Slide1

  1. Like the median nerve it is vulnerable to compression as it traverses across the elbow and the wrist though the sites in the case of the ulnar nerve are different. Approximately 8 to10 centimetres above the medial epicondyle of the humerus the ulnar nerve lies posterio-medial to the brachial artery and anterior to the medial head of the triceps and is posterior to the medial inter-muscular septum. This septum is continuous from the medial epicondyle to the coraco-brachialis muscle. A fibrous arcade extending from the intermuscular septum and made of the deep brachial fascia covers the ulnar nerve at this site and may compress the nerve. This fibrous arch was described by John Struthers the Scottish anatomist and is named after him. The previous chapter on compression of the median nerve around the elbow also included a similar ligament arising from an abnormal origin of the pronator teres from the humerus which too was described by John Struthers and is named after him.

Slide2

Slide3

Slide4

Dissection specimens courtesy Maksud Devale, Sumit Hadgaonkar and Neeraj Babhan.

  1. From here on the ulnar nerve lies behind the medial epicondyle and is medial to the olecranon. This is the cubital tunnel the roof of which is formed by a tough and somewhat taut fascial layer which extends from the origin of the flexor carpi ulnaris on the humerus named after Osbourne. Barring this fascial structure the nerve for all practical purposes is subcutaneous at this point. From here the ulnar nerve enters the forearm between the humeral and ulnar head of the flexor carpi ulnaris.

Slide5

  1. All the structures mentioned above may be associated with a compression of the nerve the commonest probably being in the cubital tunnel and this is the second most common compressive neuropathy after the carpal tunnel syndrome involving the median nerve in the arm described in the previous chapter.
  2. While taking the history of the patient suspected of having compression of the nerve around the elbow, past injuries around the elbow joint should be enquired into. This includes injuries or fractures around the elbow. Any occupation involving movements which would lead to a valgus stress should also be enquired into and noted. Rarely a single episode of a severe twisting injury or a hyper extension injury can lead to an ischemic episode leading to neuritis and which might resemble later as a cubital tunnel syndrome. The symptoms usually begin with tingling and numbness in the little and ring fingers accompanied by pain and tenderness in the medial half of the elbow particularly over and around the medial epicondyle and is severe when the nerve is pressed upon in the humeral sulcus or the cubital tunnel. As the condition progresses the weakness of the ulnar intrinsic muscles can lead to clumsiness in actions involving adduction of the thumb and disturbance of proprioceptive actions. Overtime the wasting of the muscles on the ulnar side of the palm becomes quite evident. A Tinels sign is almost always positive from the beginning. Active flexion of the elbow against resistance causes pain at the site and a combination of local pressure and the flexion manoeuvre up to sixty seconds leading to severe pain is conclusive of the diagnosis in a vast majority of cases. In early stages conservative treatment with splints anti- inflammatory agents and a temporary change in the job description may help the condition. Soft padding around the elbow to prevent trauma or counselling on how to prevent certain actions can also give relief
  3. As with the compressive neuropathy of the median nerve at and around the elbow a differential diagnosis of the exact cause of the compression of the ulnar nerve around the elbow may not be always possible because the nerve though compressed in the cubital tunnel might also have other contributing factors for example a pincer action of the two heads of the origin of the flexor carpi ulnaris muscle or a fascial band above the elbow called the Struthers ligament. (Please see para2) All the hard and soft parts in this area develop from modification of the same mesenchymal mass and the condition might be a single phenotype with adjoining abnormalities. This probably has a bearing on the surgical procedure that is employed where a complete exposure of the nerve above and below the elbow is safer from the point of view of giving a final and a lasting result. Generally speaking the results of surgery to decompress the ulnar nerve around the elbow are not as satisfactory as after the release of the carpal tunnel syndrome and for this reason nerve conduction studies play an important role in locating the compressive lesion more accurately or to rule it out and arrive at a diagnosis of a non-obstructive neuropathy
  4. Compression of the nerve and the consequent symptoms and signs which result from reduction of the space in the cubital tunnel following injuries such as fractures are outside the description given in the preceding paragraph and form a distinct entity. A sequestrum, osteophytes or a shallow sulcus following a malunion forcing the nerve to displace\sub-luxate outside the tunnel during flexion among other things can play a part in the ensuing pathology also called a tardy palsy. In such cases an anterior transposition of the nerve after adequate decompression of all offending structures around the cubital tunnel is considered the best possible treatment. The question as to if a sub muscular placement is better than a subcutaneous\sub fascial placement when the nerve is transposed is a matter of debate though the subcutaneous\sub fascial placement is by-far the simpler of the two options. As explained in the previous paragraph the procedure of anterior transposition must ensure a fair amount of mobilisation of the nerve so as to eliminate any possible compression by causes enumerated earlier such as fibrous bands (ligament of Struthers) above the elbow and the pincer action of the dual origin of the flexor carpi ulnaris at the elbow. A medial epicondylectomy can be performed at the time of the anterior transposition if found necessary. Generally speaking an in-situ decompression with a limited incision is not favoured because should it fail subsequent surgery to transpose the nerve becomes that much more difficult. Localised lesions above and at or below the elbow with a normal capacious cubital tunnel are uncommon and have to be proved by conduction studies as mentioned earlier.
  5. The incision for the procedure is vertical and is centred on a point between the medial epicondyle and the olecranon and extends about eight cm. superiorly. It is most convenient to expose the ulnar nerve first in the ulnar sulcus behind the medial epicondyle and then trace it upwards and in so doing identify a cutaneous branch of the antebrachial nerve and retract it out of harm’s way. The medial intermuscular septum is next identified which lies anterior to the nerve and any fascial structures going across the nerve from the septum are released including any offending fibres of the septum itself. This is the area purportedly of the Struthers ligament. The nerve is then followed downwards into the cubital tunnel and its passage through the pronator\flexor origin is inspected for any compressive pathology and if present this is released. At this point the nerve is inspected for any subluxation out of the cubital tunnel while flexing and extending the elbow. The tunnel itself is inspected for any post traumatic artefacts or an abnormally large medial epicondyle. The artefacts are cleared and a medial epicondylectomy can be performed at this stage if indicated. If the cubital tunnel is shallow and if this shallowness is responsible for the subluxation of the nerve  a decision is taken to transpose the nerve anteriorly.  In so doing the connective tissue around the nerve is kept intact so as to preserve its blood supply most of which runs along the nerve and this is best done by retracting the nerve by a soft catheter around it. As the ulnar nerve gets gently retracted, its branches from its posterior surface to the flexor carpi ulnaris and the ulnar profundus muscles come into view. They need to be preserved if necessary by gentle teasing and mobilisation. A thorough distal inspection of the nerve is then performed and any fibrous bands likely to impinge on the nerve in its new transposed position are cut away. In order that the nerve does not regress to its earlier position the soft tissue under the skin flap is sutured to a part of the anterior periosteum of the medial condyle to prevent the nerve sliding back irrespective of the  new placement of the nerve sub fascial or sub muscular. The skin is closed in one layer which includes the subcutaneous tissue. Because the incision extends into the lower half of the upper arm the tourniquet is applied a little higher and most surgeons prefer general anaesthesia for the procedure.
  6. Below are reproduced photographs of a patient who had both, the ulnar and the medial nerve pathology following a supra-chondylar fracture, corrected and fixed with implants. Pictures provided by Rajendra Nehete, plastic and hand surgeon, Nasik, Maharashtra, India.

Slide6

Slide7

Slide8

Slide9

Slide10

Slide11

The following pictures are of Ulnar nerve transposition courtesy Mukund Thatte, plastic and hand surgeon, Mumbai involving an abnormal insertion of the triceps, compression by the Struthers ligament  as well as compression in the cubital tunnel.

Slide12

Slide13

Slide14

Slide15

  1. From here on the ulnar nerve courses over the interosseous membrane till it approaches the wrist where it lies superficial to the flexor retinaculum and then divides into two branches superficial and the deep The superficial branch supplies the palmaris brevis a cutaneous muscle and supplies sensations to the whole of the little finger and the ulnar side of the ring finger as well as the hypo-thenar area. The deep branch of the ulnar nerve is more important because it supplies all the interosseous muscles (both palmar and dorsal) the adductor of the thumb and the ulnar lumbricals. A structure called the piso-hamate ligament crosses superficial to the passage of the ulnar nerve over the flexor retinaculum and encloses it in a tunnel named after Guyon who described it in 1861. The ulnar nerve is vulnerable to compression in this area by sheer lack of space (sometimes brought on by inflammation in the surrounding area and may be temporary) or by space occupying lesions such as a ganglion, post traumatic residue of a fracture of the hook of the hamate or its non-union, non-specific inflammatory conditions or a post traumatic aneurism of a branch of the ulnar artery which lies medial to the nerve on a deeper plane and is separated from the nerve by a fascial structure. Repeated trauma to the hypothenar area adjoining the wrist or sustained pressure to the area by a handle of a two-wheeler is known to cause a compressive neuropathy in this area. This condition is far less common than the carpal tunnel syndrome but it can lead to clumsiness of actions involving the adductor muscle wasting of the hypothenar area and may result in clawing of the ulnar fingers with extension at the M.P. joints and flexion of the interphalangeal joints  As in other compressive neuropathies the condition begins with altered sensations (in the hypothenar area in this instance) tingling and numbness and a deep ache. The differentiating feature being intact sensation on the dorsum, since the dorsal sensory branch is given proximal to the wrist in the lower part of the forearm and is not compressed.

Slide16

Slide17

Slide18

 

  1. In mild early cases a splint in a neutral position and rest and reducing pressure on the hypothenar area might help the patient. In more severe cases where pain is exacerbated by local pressure or by forced radial deviation and muscles are affected surgery will need to be undertaken after an x ray preferably a C.T scan to look for undiagnosed fractures of the hamate particularly in the region of its hook. A M.R.I. can also help to diagnose soft tissue lesions that might be causing pressure on the Guyon’s canal. An electro diagnostic test such as a sensory nerve action potential (SNAP) of the ulnar nerve will help confirm compression. Such diagnostic precautions are essential because the condition is uncommon its muscular manifestations are not always apparent and a post traumatic arthritic pathology in the region might be all that the patient has and can be treated without surgery.
  2. The incision in the palm used to release the median nerve from the carpal tunnel can also be used to release the ulnar nerve from the Guyon’s canal except that it might have to be extended by about a centimetre proximally towards the wrist and also across it parallel to its transverse crease (please see diagram above). The soft tissues are incised and retracted and the free border of the hypothenar muscles is identified. The hook of the hamate is palpated by the tip of the index finger and the Guyon’s canal is located. It is in the region of the fascia covering the proximal free border of the hypothenar muscles that the deep branch of the ulnar nerve makes its appearance after going around the hook of the hamate and travels across the palm to supply the adductor of the thumb and is usually accompanied by a leash of blood vessels. The fascia in the proximal part of the hypothenar muscles needs to be carefully tenotomised to expose the deep branch fully and is then traced proximally to its origin from the ulnar nerve which is then released from the confines of the Guyon’s canal by de-roofing it with a scissors introduced in the canal. A carefully introduced small right angled retractor when lifted will demonstrate if the canal is fully opened or not and will also determine the presence of any tightness of the ante brachial fascia. The release of this fascia if required as well as the release of the canal is helped greatly by the transverse extension of the vertical incision. All operative steps are undertaken under vision with magnification and the fact that the ulnar artery lies medial and deeper to the nerve must be borne in mind. Also if the cause of the compression happens to be a small post traumatic loose piece of the Hamate bone (sequestrum) or an abnormal post traumatic dilatation of a blood vessel (an aneurism) those conditions must be dealt with. The wound is closed after haemostasis. The nature of anaesthesia for this procedure is no different from the ones used for the release of the carpal tunnel syndrome which have been narrated in the previous chapter. Following photographs have been supplied courtesy Rajendra Nehete, hand and plastic surgeon, Nashik, Maharashtra, India. The incision employed here is similar to the one described in the text above.

Slide19

The following pictures are kindly provided by Mukund Thatte, hand and plastic surgeon, Mumbai.

Slide20

Slide21

Slide22

Slide23

Slide24

November 15, 2017

66. Compression neuropathy of the median nerve in the upper arm

Filed under: Chapter 66,Uncategorized — ravinthatte @ 4:45 am

66. Compression neuropathy of the median nerve in the upper arm

The contribution of Mukund Thatte, hand surgeon, in editing and supplying information and providing illustrations, is acknowledged. The illustrations of dissected specimens were entirely the work of Maksud Devale (Professor) Chirag Bhansali and Gaurav Kadakia senior residents in the department of plastic surgery at the Lokmanya Tilak Municipal General Hospital and medical college Mumbai India. Professor Natarajan head of the anatomy department kindly consented to undertake the dissections under my supervision (Ravin Thatte).

  1. The most frequent compression neuropathy in the arm is that of the median nerve as it courses under the flexor retinaculum of the wrist which encloses a space called the carpal tunnel underneath the carpal ligament. This forms the central third of the retinaculum and the neuropathy is called the ‘carpal tunnel syndrome’ (CTS). The condition was briefly touched upon in the previous chapter which dealt with the general principles of compression neuropathies. CTS will be covered in detail at the end of this chapter but the median nerve can also be compressed, though less frequently, in the lower arm and in the fore arm and those conditions are narrated here first, including the anatomy of the nerve as it courses below and branches into the palm.
  2. The median nerve is a mixed nerve borrowing its sensory fascicles from the lateral cord of the brachial plexus and the motor fibres from its medial cord except for the pronator teres which might get some fibres from the lateral cord.

Slide1

  1. About three inches above the elbow in a normal adult the nerve lies between the brachial artery on the lateral side and the brachialis and the medial inter-muscular septum on its medial side.

Slide2

  1. As it courses below, in very rare case, it might encounter a ligamentous structure extending between an accessory and abnormal origin of the pronator teres muscle on the humerus to a spur on the same bone under which the nerve must pass unlike the brachial artery which lies superficial to this structure. The ligament is named after Struther also called an arcade.

Slide3

  1. The main symptom of these entrapments is pain which gets exaggerated when resistance is applied to pronation. A solitary entrapment by the Struthers ligament is not easy to diagnose though evidence of a humeral spur on a plain radiograph or a C.T scan can help. Should such a diagnosis be clinched then surgery involves a simple release of the band.

Slide4

  1. Below, the median nerve is related to the two origins of the pronator teres muscle between which it passes. (The humeral and the ulnar head). This is also the area which is covered by a tough structure called the bicipital aponeurosis which is a modification of the deep fascia of the area shown in photographs of a dissected forearm in an earlier paragraph.
  2. Rarely the nerve might pass deep to both heads of the pronator teres or an abnormal dense band might be present between the two heads of the pronator teres muscle leading to impingement of the nerve. This condition is particularly common in individuals whose job involves repeated forceful actions of flexion and pronation. The tough nature of the bicipital aponeurosis perhaps contributes to the condition. This condition is called the pronator teres syndrome. The main symptom of this condition is pain, exaggerated when pressure is applied to the free border of the pronator in the upper third of the forearm in full supination or when flexion at the elbow or pronation of the forearm is resisted (The provocation test). See illustration above.
  3. The condition may result in altered sensibility over the thenar eminence and the index as well as the middle finger. The diagnosis is mainly clinical.

Slide5

  1. To treat the condition the exposure of the area is done by an incision in front of the elbow in the form of a lazy S and as the first step the bicipital aponeurosis is incised and released and retracted to expose the two heads of the pronator teres. They in turn are retracted to expose the median nerve and the obstruction to or compression of the nerve by the two heads of the pronator becomes evident following which the nerve is released from the pincer action of the two heads of the muscle. The obstruction might be in the form of a fibrous band or just thickened fascia. Occasionally a bulky part of the muscle might have to be myotomised. The incised bicipital aponeurosis is not closed and the resulting defect is left open. This allows the space around the pronator to remain capacious and helps to resolve the pathology (see illustrations above). The incision used for the procedure can also be used to explore the area above the elbow to feel for and then release the Struther’s ligament if present.
  2. As the median nerve courses down from this area, it for all practical purposes is a dual conduit because the fascicles of the anterior interosseous nerve (A.I.N.) are lying separately within the same epineurial The A.I.N branches from the median nerve here from its posterior surface to travel deep to it over the interosseous membrane. The anterior interosseous nerve may on rare occasions get compressed here by the overarching fibrous arch of origin of the flexor digitorum sublimis. The A.I.N. specifically supplies the flexor digitorum profundus of the index finger and sometimes the flexor digitorum profundus of the middle finger but always supplies the flexor pollicis longus and the pronator quadratus. Its sensory distribution is restricted to carpo-metacarpal joints and the radio ulnar joint. The compression of only the A.I.N. therefore results in weakness in the flexion of the interphalangeal joint of the thumb and the weakness of the long flexor of the index specifically without any loss of sensations over the thenar eminence. This is usually called the anterior interosseous syndrome which causes pain locally and which may radiate along the course of the nerve. The sensory supply to skin over the thenar eminence comes via a branch of the median nerve about 5 cms proximal to the flexor retinaculum of the wrist and the presence of altered sensations over the thenar eminence together with weakness of the long flexor of the index and the thumb usually indicates a compression of the main trunk of the median nerve before the exit of the A.I.N. The treatment of the A.I.N. syndrome involves employing an incision similar to that described for the pronator syndrome but might have to be extended a little lower so that the tendinous fibrous arch of the sublimis can be divided under vision. In reality the release of the ligament of Struthers if present, the release of the median nerve in the pronator syndrome and the division of the fibrous arch of the sublimis in the A.I.N. syndrome may be accomplished in a single surgical procedure because an accurate differential diagnosis of each separately is not always possible.

Slide6

  1. This brings us to the course of the median nerve under the flexor retinaculum of the wrist. The retinaculum is divided into three parts the central third of which is the toughest and is spread across the carpal bones and is called the carpal ligament. The proximal part is a continuation of the ante brachial fascia and the distal third continues as the somewhat thick palmar fascia. The retinaculum in the distal third is attached to the borders of the thenar and hypothenar muscles. The description of the density of these structures (ante brachial fascia and the palmar fascia) is important because they too may contribute to the compression of the nerve and a mere release of the retinaculum and the carpal ligament may not suffice. This additional release is usually achieved after inspection by the naked eye following the release of the retinaculum. On either side of the retinaculum lie the long flexors of the wrist at their insertions. The palmaris longus tendon inserts in the proximal free border of the flexor retinaculum and then spreads over it as a fibrous insertion. The median nerve accompanied by the median artery is the most superficial structure when the retinaculum is opened. The flexor superficialis and profundus tendons to the four fingers lie below the nerve in that order and the flexor pollicis longus lies on the radial side of these tendons. Because the median nerve is the most superficial structure here, in extremely rare cases it may be horrendously mistaken for the palmaris longus tendon at the time of its blind harvest as a tendon graft. The median nerve under the retinaculum carries the motor fascicles for supplying the small muscles of the thumb namely the abductor pollicis brevis, the opponens pollicis and the flexor policis brevis (the superficial head). These fascicles emerge as the recurrent branch of the median nerve which most frequently emerges beyond the distal margin of the flexor retinaculum. The emergence of this branch is however subject to variations in one of which it pierces the retinaculum while underneath it. That as well as other variations are included in the figures below.  It is best therefore when planning the incision to  place it about a centimetre on the ulnar side of the Thenar crease (see illustrations below).

Slide7

Slide8

  1. The principle features of C.T.S. are altered sensibility on the radial side of the palm and radial side three and a half fingers sometimes leading to anaesthesia, weakness of the thenar muscles leading to clumsiness in actions performed by those muscles for example abduction or opposition by the thumb accompanied by pain particularly at night. In fact nocturnal pain on the radial side of the hand might be the only symptom that might bring the patient to the clinician when the other clinical features have not manifested. C.T.S. of some duration will result in wasting of the thenar muscles. The diagnosis is clinical in a vast majority of cases by way of tests shown in the figures below. If a psychosomatic element is suspected or in cases of suspected malingering electro diagnostic tests may be useful. Such tests might also be undertaken to judge the results of surgery if the patient complains of lack of relief following the surgical procedure. Many units however use electro-diagnostic methods as a routine.

Slide9

Slide10

Slide11

Photographs courtesy Bipin Ghanghurde

  1. Many or most patients consult surgeons after some form of medication has been tried for C.T.S. Anti-inflammatory drugs are the most frequently used. Many patients try massaging, some try some form of alternative medicine and others take a variety of exercises before seeking a surgical opinion. In the surgeon’s hand two forms of conservative treatments are available, injection of corticosteroids under the flexor retinaculum or splinting. Of these two, splinting in the position of function with the wrist extended in 30degrees extension has been objected to because of the increase in pressure it would cause within the carpal compartment. The neutral position is therefore preferred and that too in the form of night splints. Among the corticosteroids dexamethasone is preferred because it causes the least injury if inadvertently injected into the nerve. Of those who undergo surgery there are those who find the condition unbearable even after some form of conservative treatment or those that are convinced by the surgeon of the effectiveness of the surgical treatment soon after the first surgical consultation as opposed to any form of expectant conservative treatment. Surgeons may occasionally take recourse to conservative treatment in the form of injections of corticosteroids to give temporary relief and suit the patient’s convenience to postpone surgery for some time.
  2. Surgical treatment consists of laying open the flexor retinaculum in its entirety (including the distal palmar fascia and the proximal ante brachial fascia if required) to relieve pressure over the nerve and its emerging branches and to leave those layers open. Only the skin and subcutaneous tissue is closed at the end of surgery. This briefly describes the open approach. An endoscopic approach has been described in recent years with “key hole” incisions and special instruments have been devised for this purpose. Only a minority of surgeons practice this method probably because the incisions employed in the open approach are not very long and the hospital stay in either method is no different, most patients being treated on a day care basis. The cost of endoscopic instruments, the learning curve to master the technique and no evidence of the technique’s superiority over the open approach might be the other reasons why the method has not gained adequate popularity.
  3. The incisions employed to treat C.T.S are many but they mainly fall in two parts, an incision employed in the palm parallel to the main thenar crease on its ulnar side (Please see figure above para12) and another incision in the transverse wrist crease. If they should be joined in the form of a lazy S is a matter of choice. As far as possible a vertical incision across the wrist crease should be avoided because it transgresses the horizontal arrangement of the elastic fibres within that crease and can lead to a bothersome and conspicuous hypertrophic scar. Surgery is performed under a tourniquet on the arm except in very obese individuals where the tourniquet is applied on the forearm. Most surgeons prefer not to employ formal general anaesthesia with an intratracheal intubation but a few surgeons opt for a laryngeal mask and some form of anaesthesia. A vast majority employ a combination of deep infiltration of a local anaesthetic agent after sedation because the tourniquet time is not long. The tourniquet is raised after the infiltration and the patient is prepared and draped. Because some specialisation is required to execute a brachial or an axillary block that practise is also not commonly employed. Intravenous analgesia with the tourniquet raised ahead of the injection of the analgesic agent is also effective but is employed only in some units.
  4. The surgery is begun in the palm. After the skin is incised the palmar fat is visualised which is cut and retracted and the distal part of the flexor aponeurosis is identified. A blunt dissection is employed to identify structures entering the palm from underneath the retinaculum particularly the motor branch of the median nerve to the thenar muscles if it is following its most common course. If not the focus shifts to the main trunk of the median nerve emerging from underneath the retinaculum. A scissor can then be introduced under the retinaculum as ulnar-wards as possible to the median nerve and is opened to create a space in the carpal tunnel. The scissors are then employed to undermine the skin superficial to the retinaculum up to the wrist crease and a retractor is placed in the subcutaneous space and is lifted to expose the flexor retinaculum in almost its entirety and brought under vision. At this time the scissors can now be employed to cut the retinaculum as well as its carpal ligamentous portion up to the proximal wrist crease. In the past it was customary to trim any abnormal swelling in the sheath of the flexors under the retinaculum. This practise now appears to be on the wane unless the swelling of the sheath is abnormal and occupies the whole of the space under the retinaculum in which case the bulky synovial sheath is excised and biopsied. Only in those cases where the ante-brachial fascia appears to be tight on visual inspection or palpation that a transverse incision may be employed in the wrist crease to expose it and is then carefully incised with a 15 number blade under vision to release the last remnants of the compressive pathology. Since the dissection was begun in the palm any tightness of the palmar fascia will have been dealt with when the retinaculum was identified. All visible bleeders are cauterised and the wounds are closed, skin and subcutaneous tissue together, with interrupted stitches. A bulky soft tissue dressing is given preferably with a splint to immobilise the wrist for a week when the stitches are removed and gradual active and passive physiotherapy follows. Usually the patient is ready to do all normal activities within two weeks. Intra operative photographs with a small incision which allows all the steps mentioned in the above paragraph and showing some specific anatomic structures not mentioned in the above paragraph are reproduced below. Photographs courtesy Mukund Thatte.

Slide12

Slide13

Slide14

Slide15

Slide16

Slide17

Slide18

Slide19

Slide20

Slide21

Slide22

Slide23

  1. The results following surgery of C.T.S. are satisfactory in a vast majority of cases. If the diagnosis is correct and the release of the carpal tunnel is complete. The bothersome altered sensations as well as pain disappear even before the stitches are removed. Wasting of thenar muscles is another matter. If they can be brought back to their original size will depend upon the efforts that the patient undertakes to retrain them as well as the amount of wasting that has already occurred. There appears to be some disagreement on the subject as to whether the power really comes back to the original following surgery. Irrespective whether the size and strength are regained or not the clumsiness that the patient experienced in certain actions pre-operatively almost always disappears. Conditions such as obesity or diabetes which predispose to many a condition including C.T.S. have been narrated in the previous chapter. They will have a certain bearing on how the patient will do in the long run.

Addendum:

Dr. Beng Hai from Singapore, who was a faculty at the recent meeting of the Indian Society for the Surgery of the Hand, together with the Singapore society 2017, gave two examples of how a severely fibrosed median nerve after the release of the carpal tunnel syndrome can be neurotomised parallel to the fascicles in order to restore its function (photograph to the left). He also pointed out that occasionally a space occupying lesion within the carpal tunnel can produce features of a carpal tunnel syndrome and can be usually diagnosed by an ultrasound examination (photograph to the right).

Slide24

September 7, 2017

65. Compressive neuropathy of the peripheral nerves in the upper limb General information

Filed under: Chapter 65,Uncategorized — ravinthatte @ 6:26 am

Compressive neuropathy of the peripheral nerves in the upper limb: General information

The speciality of the surgery of the hand (also called hand surgery) is now over 50 years old in India but older in the western part of the world. Over the years both orthopaedic as well as plastic surgeons have first migrated towards this speciality and then taken it up as a full-time occupation. A general surgeon taking up this speciality is more an exception than a rule. This chapter has therefore been vetted by Mukund Thatte a plastic surgeon and a leading practitioner of surgery on the brachial plexus and peripheral nerves as well as two orthopaedic surgeons Sudhir Warrier and Pankaj Ahire both of who restrict their practice entirely to surgery of the hand. All three have their practice in Mumbai India.

This chapter focuses only on peripheral neuropathies in the arm and does not include conditions which involve the brachial plexus or conditions such as the thoracic outlet syndrome.

  1. All activity within living tissues can be described as electro chemical in nature and this in recent times has been collectively called physics. Slide1 Erwin Schrödinger’s work on the genetic makeup of living beings in his seminal work published as “What is Life” has shown that all living activity can be reduced and explained as principles of physics. Nowhere else in the body is this electro-chemical activity more evident than in the functioning of the nervous system. The nervous system is not only aware of the conditions that prevail within the body and is able to react to the changes that occur with appropriate responses but is also aware of the organism’s environment and allows suitable actions to be taken to safeguard the interests of the organism.
  2. The agents for the perception and execution of these actions are the nerves made up of axons the longer of the two cytoplasmic projections from the neuron or the nerve cell. The shorter of the two projections the dendrites, in a vast majority, serve as connections between adjacent neurons.
  3. The peripheral nerves in the limbs are the longest nerves in the body which traverse long distances through anatomical compartments and tunnels and are therefore prone to pressure and or compression at various sites. Because the hand as an organ is far more skilful than the foot and is vital to a myriad of daily activities, compressions of the nerves in the arm leading to clinical problems appear to be more frequent than those in the lower leg. As noted in the preamble to this chapter this statement excludes the conditions which arise because of problems related to the vertebral column in the inferior extremity.
  4. The basic unit of the nerve is the axon a long protoplasmic extension from the neuron and is called axoplasma. A few axons make a fascicle and several fascicles make a nerve. The axons are covered by a connective tissue layer called endoneurium, fascicles are sheathed by connective tissue called the perineurium and the nerve in turn by the epineurium which is quite thick sometimes up to forty percent of the cross section of the nerve. The epineurium has a mesentery called the meso-neurium through which blood vessels enter or leave to fulfil the nerve’s metabolic requirements.
  5. The axons can be large in diameter or small. They can also be myelinated or non-myelinated. The non-myelinated axons are fewer in numbers. Myelination is an attempt by nature through evolution to ensure faster conduction of the electrical impulse without spillage. The myelin coating of the axon is laid down by the Schwann cells. Because the distance that the electrical impulse must travel is long the axons have nodes first described by Ranvier (nodes of Ranvier). These nodes act as substations like in man-made electrical grids where conduction is optimised by a saltatory process. (Saltatory as in leaping). These nodes in fact are relay stations. The myelin sheath is interrupted at each node. As can be seen the non-myelinated fibres are inferior in their conducting efficiency. Though they are surrounded by Schwann cells they do not provide them with a myelin sheath.

Slide2

  1. The axon is enclosed within a layer of endoneurium a layer not previously mentioned in the paragraph above. The endoneurim itself is extremely thin and is made of connective tissue of mesodermal origin and encloses a network of capillaries more profuse than in the sub-perineurial layer and the capillaries are broader in diameter than the capillaries elsewhere in the nerve probably on account of being the terminal vessels actually nourishing the nerve tissue. What is more the nerve mimics the brain by creating a blood nerve barrier here in which together with the subperineural blood vessels, a privileged environment is created which resists deleterious effects of metabolic changes that occur on the outside. When this limit is crossed by an external force as happens in a compressive neuropathy an ‘internal compartment syndrome’ results. Because the nerve itself has no lymphatic drainage the resultant oedema leads to accumulation of proteins and the loss of privilege incites an inflammatory response to antigens from which the axon had been protected earlier. Lymphocytes and macrophages follow into this zone of inflammation. The myelin sheath gets destroyed first in patches then over a length followed by formation of scar. The conductivity of the nerve suffers and if the condition is not treated till the effects of the compression are reversible the area of supply of a given nerve suffers consequences such as anaesthesia or loss of function of muscles. The following figures are schematic and do not purport to be real cross sections of a nerve but are drawn to understand how the structure of a nerve is organised. For example, the myelin sheath is pearly white in colour but shown here in black because it is very difficult to show a white pearly appearance in a diagram. The same applies to all the sheaths.

Slide3

Slide4

Slide5

  1. An acute compression neuropathy can occur following an improper use of a tourniquet on the arm ironically when surgery is being performed for treating conditions in the hand. The incidence of this kind of ‘palsy’ is much lower now because of the introduction of pneumatic tourniquets (some of them with alarms indicating the duration of application). Mercifully most patients recover completely. The available texts have paid little attention to the exact nature of the pathology that follows in the nerve in cases of a tourniquet ‘palsy’ and if any degree of rapid demyelination occurs in the affected nerves.
  2. The blood supply of the nerves develops as the nerves grow in the limb buds and it is this neuro-ectodermal tissue that orchestrates the development of the capillary network in its vicinity which later develops into vessels. The rationale of a neuro cutaneous flap is this synchronous development. The median nerve in the forearm for example is supplied by the median artery which overlies it and also by the branches of the anterior interosseous artery in the same fashion that the radial artery supplies branches to the radial artery forearm flap. The ulnar nerve near the elbow is supplied specifically by the ulnar collateral arteries which draw their blood supply from the brachial artery and have been used for a free ulnar nerve transfer. The blood supply to the nerve as can be seen is either axial or segmental.

Slide6

Slide7

  1. It has to be borne in mind that the axons are open live conduits and their axoplasmic flow is bidirectional. This means that the products of abnormal metabolism have a free play in either direction. Therefore, a compression pathology in the proximal part of a nerve may have consequences in a distal part of the same nerve when it lies in a vulnerable compressible area. For example, a patient with a thoracic outlet syndrome may later develop a carpal tunnel syndrome. This is called somewhat harshly as a ‘double crush’. This can happen the other way around as well and is called the reverse double crush in which a distal lesion can precipitate a proximal pathology. Diabetes obesity, hypothyroidism, abuse of alcohol and tobacco the usual culprits in many diseases have also been statistically proved to have a role as predisposing factors in the development of compression neuropathy. A hereditary condition in which trivial trauma precipitates demyelination in nerves leading to symptoms both motor and sensory might sometimes be confused with a compression neuropathy. These cases show a rapid onset and total recovery they may be recurrent and occur at various sites. Clinicians must have this condition at the back of their minds before arriving at a diagnosis of compression neuropathy which has a steady progressive course.
  2. Most living tissues have an optimal ability to stretch and the nerve is no exception. The nerve in some measure resembles a woven rope as fascicles traverse distally and get straightened if stretched. The mesoneurium also has a certain play when it gets stretched. Nature therefore protects the nerve while the body pursues normal activities but is vulnerable when a certain limit is crossed particularly when the stretching action is performed repeatedly. Modern life creates many situations which put the body and particularly the upper arm through repetitive abnormal movements in certain occupations. The significance of this is not so much in the causation of the compression pathology but in the effects that this stretching produces when the nerve is already beginning to get compressed because the compressed nerve tends to lose its elasticity and therefore suffers repeated trauma. Ironically the practice of yog now popular all over the world to ward off the ill effects of modern living if practiced with excessive and unnecessary vigour can aggravate many an existing condition in the limbs as well as a compressive neuropathy. These facts are important when taking the history of a patient with compression neuropathy.
  3. The preceding paragraphs form a background with which a clinician must be familiar so as to be able to diagnose a case of compression neuropathy. What follows is taking down a detailed history which includes the additional information that the patient gives on his own, physical examination and electro diagnosis when there is a doubt about the diagnosis.
  4. The patient’s complaints more often than not are sensory in nature for example tingling and numbness. It might be revealed on direct questioning that the sensations that the hand generates are not quite what they should be (paresthesia). Aching pain and fatigue are caused by muscular weakness but the ache that the patient complains of might in fact be severe numbness. The tingling might be getting aggravated by activity and there are patients who are miserable enough with their symptoms to lose their confidence for doing their daily activities. Insomnia is not unknown. A patient might complain that a particular action is difficult to perform for example turning the key for opening a lock or that a particular area of the palm is dry and rough. It might also have been noticed that the affected hand has become weak. There might be symptoms of intolerance to cold or hot objects. Generally speaking the symptoms of a compressive neuropathy vary greatly and only the common ones have been narrated here.
  5. Notwithstanding the variety of tests that have been described to test for loss or altered sensations the results of these tests are not always reliable or conclusive on account of their subjective nature. If the condition is unilateral it helps a great deal to make a comparison and then arrive at a firmer conclusion. Light touch can be measured by moving cotton across the affected and the contralateral normal part and then measured in ten grades (one to ten) and compared. The capacity to feel a vibratory impulse can be tested either by a tuning fork or by a specially designed instrument with multiple frequencies because there is a theory that high frequencies are lost the earliest in compression neuropathies. Cutaneous pressure thresh holds can be tested by mono filaments of increasing diameters till they bend and two – point discrimination formerly tested with a paper clip is now measured by instruments which are more sophisticated. However, as things stand two-point discrimination is one of the last sensory modalities to be lost in compressive neuropathy and is a poor diagnostic tool to diagnose the condition early.

Slide8

  1. The motor impairment in the palm is somewhat easier to diagnose though the exact amount of loss of power in the small muscles of the hand cannot be graded as is done in the larger muscles in other parts of the body. Wasting of muscles in the palm is also easier to diagnose particularly when compared to the opposite side but here too the clinician must take into account which of the two hands is dominant. Many a times the non-dominant hands have leaner palms. While the hand is being examined it is worthwhile to observe palmer sweating. Though there is very little that we know of the autonomic component of the nerves in the hand the region supplied by the affected nerve is more likely to be dry.
  2. Perhaps the more reliable methods to diagnose nerve entrapment are by the use of percussion or pressure on the known course of the nerve or to cause provocation by bending the joint to an extreme position for a minute across which the nerve passes in a canal. The manoeuvre causes reduction in the space of the canal in which the nerve lies and produces exaggeration of the symptoms that the patient is suffering from. In the case of the median nerve pressure can be applied over the middle of the pronator teres resulting in pain, percussion can be done proximal to the carpal tunnel leading to unpleasant tingling along the nerve and provocation can be induced by extending or flexing the wrist through its maximum range with the forearm in the supine position for a minute which causes the symptoms to increase several folds. These tests will be given in detail with figures in sections on individual nerves later in this blog.
  3. The nature of the impulse in the nerve being electrical and the result of that impulse on the muscle also being electrical the rational thing has been to subject cases of compressive or other neuropathies to electro diagnosis. This is a speciality in itself and only the bare minimum information is provided here. The electro diagnosis is divided in two parts, electro- myography and nerve conduction studies. In myography a sharp needle is inserted in a muscle and its electrical activity is noted on a graph. A muscle which has been denervated for a long time and is wasted and in which the muscle fibres are replaced with fibrous and collagenous tissue is silent and will not transmit any impulse across the needle. A muscle which has lost its nerve supply completely approximately for a period of more than two weeks will show fibrillations which denote an autonomous electrical activity in the muscle. A normal muscle upon insertion of the needle responds with a brief burst of electrical activity. When the patient is asked to contract the muscle with the needle in place a normal muscle recruits a large number of muscle fibres leading to what is known as interference pattern because of overlapping. In a muscle recovering after a successful repair of a nerve serial myographies will show a greater recruitment of muscle fibres over a certain duration.
  4. Nerve conduction studies are performed by placing two electrodes along a nerve one of which is the stimulating electrode and the other is the receiving electrode. The conduction can be studied in either direction. Unlike the motor axons which are bigger the sensory axons are smaller the amplitude of the waves generated in them is also smaller and the electrical activity is expressed in microvolts as compared to in the motor axons which are designated in milli-volts. It is customary to measure the speed with which the impulse passes in milliseconds. Because the quantities involved are very small the investigation can be marred by room temperature the temperature of the surface on which the electrodes are placed or by technical problems. Therefore, a comparison with values on the normal side is far more important in nerve conduction studies. A difference of about fifty percent between the two sides is considered diagnostic of a pathological entrapment of the nerve.

Slide9

Slide10

Slide11

Slide12

  1. It is a moot point as to if in clinical practice treatment should or can be undertaken without recourse to electro diagnostic methods in cases of compressive neuropathy or if these methods are used only when the diagnosis is doubtful and in those cases where the patient needs to be convinced of the diagnosis.

 

 

September 5, 2017

64. Postmastectomy reconstruction of the breast

Filed under: Chapter 64,Uncategorized — ravinthatte @ 7:08 am

This chapter was written with the help of Prashant Govilkar a consultant plastic surgeon in the United Kingdom and Bijoy Methil a consultant plastic surgeon in Mumbai India.

  1. The breasts are a very important and overt feature of a woman’s sexuality. In addition, the fact that the organ is used by her to feed her offspring means that the breasts are a vital part of her biological persona. What is more the shape of the breast mound as well as its projection together with the nipple areola complex from the chest wall has been considered the most attractive and beautiful part of the human female anatomy. In none of the other mammals in the animal kingdom does the breast project in this fashion. In the event the breasts have been the subject of many an artists’ drawings paintings and sculptures. The breasts have also been dressed by a variety of clothes which covered them tightly to minimise their sexual appeal or were left partly exposed ostensibly for their titillatory effect. The corset for example flattened the shape of the breasts and at the other end the under wired brassiere not only lifted them but also facilitated a maximum show of the cleavage (décolleté). It has been alleged that wardrobe malfunctions of female public performers exposing parts of their anatomy may not always be accidental and is not necessarily frowned upon by the ladies in attendance. All in all this has been a vexed subject for millennia.

Slide1

Slide2

  1. Alas the female breast is also one of the most frequently visited organ by the emperor of maladies and the number of cases of cancer of the breast show no signs of abating partly because more cases are recognised than in the past on account of increased awareness. The absolute numbers might be rising as well because of a variety of factors which include late pregnancies, lack of breast feeding, a faulty lifestyle, obesity, environmental pollution and radiation from electronic equipment.
  2. The treatment of cases with cancer of the breast till the middle of the last century was an exceedingly radical form of surgery which included removal of the breast together with the nipple areola complex and a large portion of the surrounding skin, the pectoralis major muscle and a total clearance of all the axillary lymph nodes and occasionally removal of supraclavicular lymph nodes as well. Sometimes in advanced cases so much skin was removed that the wound could not be closed primarily and a skin graft had to be placed on an unfavourable bed. The patient was also subjected to a large and crude form of radiation. During those years reconstruction of the breast mound was virtually unknown though one of the earliest recorded use of a pedical muscle flap (latissimus dorsi) was for re construction of the breast mound (please see history of muscle flaps in the chapter (58). For the most part women suffered their post mastectomy deformation in silence or had to make do with stuffing their brassiere cup with some soft material. Today some excellent external soft prosthesis built in the brassiere are available for those women who opt not to undergo surgery to reconstruct the breast or for those women who are going through courses of radiotherapy and chemotherapy and are awaiting a surgical reconstruction of the breast mound.

Slide3

  1. After the era of radical surgery there was a phase in the seventies of the last century in which many women were subjected randomly to a soft tissue radiography with or without radiopaque nuclear dyes to diagnose the condition and many women were subjected to a sort of prophylactic or early mastectomy based on mere suspicion with or without what would now be considered as a ‘full proof diagnosis’. Some of these surgeries were also performed for what were labelled as ‘premalignant lesions’. Many of these women also underwent reconstruction with breast implants till questions came to be raised about the ethicality and the scientific basis of these treatments.
  2. Presumably we know a lot better now notwithstanding the old philosophical adage that in making scientific progress we move from one stage of ignorance to another. Here is how the situation has changed.
    1. There is widespread awareness now about the condition as compared to the past and all types of media have played a laudable role in this transformation. Many women now know the method of self-examination and this has resulted in many an early diagnosis. The media has also done a creditable job of publicising the life stories of what are called as “survivors”. A combination of early diagnosis and an optimistic patient is a ‘sea change’ from an earlier belief that cancer meant certain death and a far better informed and cooperative patient is now more a rule than an exception.
    2. The ‘hormone dependency or sensitivity’ of the tumour is now much better understood and therefore ancillary surgeries such as oophorectomies for pre-menopausal oestrogen dependent tumours or drugs to reduce the oestrogenic activity in their treatment have changed the nature and extent of surgery. The prognosis of a given case is also easier to predict and the schedule of chemo as well as radio therapy can be planned in advance and the patient can be informed as to when reconstruction of the breast mound can be undertaken.
    3. The technique of C.T or ultra-sound guided trucut core biopsy has improved considerably and a diagnosis of not only the malignant nature of the tumour but also its biological behaviour vis a vis its hormone dependency is now available pre-operatively. The concept of a formal biopsy of the sentinel node in the apex of the axilla and the conclusions drawn from it about the need for an axillary lymph nodular dissection has allowed a far more limited form of surgery leading to terms such as ‘lumpectomy’ or ‘skin saving surgery’. This has meant that an immediate reconstruction following the removal of the tumour is now possible if the margins of the excision are clear and the sentinel node is also negative for the spread of the tumour in the axilla .If the sentinel node biopsy is positive, then axillary node clearance together with the breast surgery may also be followed by immediate reconstruction.
    4. A sort of revolution has occurred in the treatment of breast cancer thanks to the science of genetics. The unusual prevalence of cancer of the breast in certain families had been known for some time. Women and even girls have now the advantage of genetic investigations and can be warned that they have inherited the culprit gene and some women are now opting for a prophylactic sub cutaneous mastectomy followed by immediate reconstruction with breast implants or other modes of reconstruction with flaps. An ethical debate is also now on as to at what age girls should be informed of their genetic predisposition because there is no way of knowing when and if the disease will strike.

Slide4

  1. The plastic surgeon when asked to reconstruct the breast, mentally divides his task in three parts namely, creation of the breast mound, the recreation of the nipple areola complex and achieving symmetry with the opposite unaffected breast. When aiming for symmetry it is usually the case that the unaffected breast is pendulous on account of age and the usual practice is to create a normal mound on the affected side and then offer a reduction in size on the normal side. However, an occasional patient might demand that the new breast should resemble the ptotic un affected breast. Photographs of patients with both these scenarios are reproduced below

Slide5

The techniques of Reduction mastoplasty are not a part of this chapter and will be covered in a different chapter. However, if the unaffected breast appears smaller than the affected reconstructed counterpart, a suitable sized breast implant can be used for that breast to achieve symmetry As to the recreation of the nipple areola complex the procedure is usually undertaken after the new breast mound has settled down and this subject is covered at the end of this chapter.

  1. Irrespective of whether the reconstruction is undertaken immediately after surgery or is delayed, three options are available to the surgeon (a) a breast implant (b) transfer of living tissue with a pedicle or by way of microvascular free tissue transfer to recreate a new breast mound or(c) a combination of both.
  2. For a breast implant to succeed an adequate skin envelope is essential. This ideally happens when a prophylactic mastectomy is performed in which the skin is completely spared including the nipple areola complex and only the breast tissue is removed. In these patients, an implant can be introduced with some difficulty through an incision in the areola which might have been used to perform the mastectomy. If the implant is to be introduced in the sub-pectoral plane then an incision in the axillary fold or a sub-mammary incision may be preferred. Photographs of a patient with breast implants after bilateral prophylactic mastectomy have been included in para 5d. In cases where skin sparing surgery has been performed and the wound has been closed primarily a judgement has to be taken as to if the available skin can be expanded by a tissue expander to ultimately accommodate a breast implant. This tissue expander as well as the breast implant to be placed later is in almost all the cases placed in the sub-pectoral plane to avoid direct pressure on the skin envelope. In most cases where skin sparing surgery has been performed the pectoralis too is usually spared. The access for the introduction of the expander is usually located at a distance from the scar on the breast on the lateral side near the anterior axillary fold and a sharp dissection is avoided and the cavity is usually created with the fingers. Some of these patients have received radiation which is one more reason not to handle the skin envelope. It is a matter of judgement as to if only an implant is the best form of treatment or should tissue be imported and an implant then placed under the imported flap.

Slide6

Slide7

  1. There are a variety of options available for recreating the breast mound. The pedicled lattisimus dorsi (L.D.flap) flap supplied by the thoraco-dorsal division of the subscapular artery a branch of the third part of the axillary artery is extremely convenient and popular because it is in the vicinity and easy to transfer and the resultant defect on the back can be closed by undermining the skin. The muscle provides the bulk and it can carry a sizable island of skin which can suffice to compensate for any shortage of skin in the recipient area of the breast. In anticipation or as a result of any loss of muscle mass, this flap can easily accommodate a breast implant even in cases where in the original surgery the pectoralis muscle had been removed. See illustrations below.

Slide8

Slide9

Slide10

Slide11

Slide12

  1. Perhaps the most suitable site for transfer of tissue to substitute for partial or complete loss of breast tissue is the lower abdomen from around the umbilicus up to the line of the pubic hair. The colour of the skin in this area is a good match for the skin on the breast, both areas being covered for most part of life and the soft consistency of the fat in the lower abdomen matches that of the breast tissue. In parous women, this tissue is usually in excess and when transferred leads to no deleterious effects. In fact, the closure of the wound after the tissue has been transferred is very easy and the result in an earlier lax abdominal wall is welcome by almost all women. Two diagrams describing this flap are printed below followed by clinical cases and then a paragraph which details its evolution towards a free microvascular flap.

Slide13

Slide14

Slide15

Slide16

  1. This lower abdominal tissue spread transversely has a dual blood supply. The more tenuous supply comes from above by way of the deep superior epigastric artery which is a continuation of the internal mammary artery also called the internal thoracic artery which in turn is a branch of the subclavian artery. The superior epigastric artery runs its course through the rectus muscle from which it sends perforators to supply the skin and these are more numerous in the upper abdomen than the lower. In the lower abdomen the corresponding artery is deep inferior epigastric artery a branch of the external iliac artery which enters the muscle from below and runs its course also through the rectus muscle running its course superiorly but its length is shorter and its perforators through the rectus muscle supplying the adjacent skin are more profuse in the lower abdomen than that of the superior epigastric artery. The idea of carrying skin of the lower abdomen as a pedicled flap based on the rectus muscle as a carrier and the superior epigastric artery as a source of blood supply is quite ingenious but requires the sacrifice of a considerable length of the rectus muscle. In fact, a flap based on this artery and its perforators in the upper abdomen was described earlier but fell into disuse probably because of two reasons. For one the skin and the subcutaneous in this area was not quite enough and of the same consistency as of the breast and the other being the closure of the defect after the flap was harvested left a scar in that part of the abdomen which is uncovered in many outdoor activities. It is on this background that a lower abdominal flap based on the deep inferior epigastric artery came to be described and used as the understanding of the vasculature in this area improved. Its disadvantage (if at all) was that the flap has to be transferred as a free microvascular flap which takes some time and is therefore not favoured for an immediate reconstruction a decision in which the oncologist and the anaesthesiologist play a part. As the time taken for micro-surgical procedures reduces and more and more surgeons become proficient in the technique the situation may change over the years. However, for creating a partial or a complete breast mound secondarily this flap is by far the best for more than one reason. The deep inferior epigastric (DIE) artery flap does not entail the loss of a considerable length of the rectus muscle as in the pedicled flap but involves taking only a small cuff of muscle from which its perforators emerge. The artery’s size as it takes off from the external iliac vessel is sizable and is therefore easy to anastomose. There has been a further modification in fashioning this flap in which sizable perforators of the deep inferior epigastric artery as they emerge from the rectus muscle are employed as the donor or source vessels eliminating the need of sacrificing even a small part of the rectus muscle. The fact that the lower abdominal wall below the crural line is vulnerable to herniation is well known because the fascia in this area is not as tough as it is in the upper two thirds of the abdomen. The harvest of the rectus muscle in the pedicled flap therefore required bolstering of this part of the lower abdominal wall sometimes with a synthetic patch. That need is eliminated completely in the perforator based flap which in its full form is called the deep inferior artery perforator flap (DIEPF).

Slide17

Slide18

Photographs courtesy Prashant Govilkar

  1. One more flap needs to be mentioned here. This flap involves harvesting tissue from the upper two thirds of the buttock the consistency of which is about the same as the breast tissue and the closure of the resultant defect is easy because of lax skin. The scar also remains hidden even in a skimpy swim-ware. The flap is supplied by the superior gluteal branch of the posterior division of the internal iliac artery and it emerges between the gluteus maximus and the medius just above the upper border of the pyriformis muscle. The vessel is sizable in diameter and easy to anastomose.

Slide19

The approximate dimension of the tissue that can be harvested is shown in faint yellow. The artery emerges in to the subcutaneous tissue in the upper part of the buttock

  1. There are innumerable free flaps described to reconstruct a post mastectomy defect but the ones mentioned above are the most frequently employed. One flap based on the deep external iliac vessel which supplies the skin as well as the fat adjacent to the anterior superior iliac spine and the iliac crest and which usually bulges as age advances is also employed for post-mastectomy reconstruction. The volume of tissue here is not very large and the flap therefore can be used only for small breasts.

Slide20

  1. Irrespective of what flap is used, the art of the craft lies in placing the flap suitable to the axis of the defect and to gauge its depth which determines the volume. The pedicled flaps such as the LD or the Tram flaps have to be transferred subcutaneously and the greater the volume the wider is the undermining of the bridge of skin under which the flap is transferred. This has to be anticipated in advance.
  2. Experience has taught the plastic surgeons to map the lower abdominal flap’s vascularity into diminishing zones irrespective of whether the flap is based on the rectus muscle or the deep inferior epigastric artery or its perforators. The vascularity is best where the vessel (or vessels) enter the flap, is somewhat diminished in the adjacent zone near the midline on the contralateral side, is further diminished in an area adjacent to the area of the point of entry of the blood vessels on the ipsilateral side and the zone farthest from the midline on the contralateral side has the least blood supply. This part of the flap may often be deepithelialised to be buried during the reconstruction to supply bulk or may even be sacrificed to avoid possible necrosis but if used is placed in the shallow area of the defect usually on the lateral side (Please see figures below para ten.) Either of these flaps, (pedicled or free microvascular) can safely accommodate a breast implant underneath them if the volume of reconstructed breast is inadequate and if the pectoralis muscle has been excised. Ideally the transferred flap is fixed to the underlying tissue (pectoralis major when present) or whatever tissue is present so that it does not slide down.
  3. Lastly the treatment of the umbilicus requires to be explained. Any operation which takes away such a large part of the lower abdominal tissue and is then closed as in a lower abdominal abdominoplasty means that the umbilicus needs to be placed in a reasonable position higher up in or near the centre of the abdomen and not be pulled down with the movement of the upper abdominal flap. The umbilicus is therefore cored out of the skin flap and is left attached to it’s stock in the anterior abdominal wall and is brought out of the upper abdominal flap by making a hole at the desired point and the fixed with sutures.
  4. As mentioned at the beginning in this text the creation of a nipple and the areola is usually performed after the breast mound is created and allowed to stabilise. There are several methods described for this purpose but the most frequently used is the one in which the areola is created with skin from the groin or rather the medial side of the thigh posteriorly near the tapering part of the labia majora. The graft is full thickness in nature and the resultant defect is closed primarily. In a bilateral case the graft is usually harvested from the opposite side so that each defect can be closed primarily without difficulty. The harvest of the graft is performed after the nipple is created so that the exact defect is known. For the creation of the nipple three triangular flaps are marked around a point at which the nipple is to be created. These flaps are equidistant from each other with their broad bases towards the centre. Only the central one third of the flaps are left attached to their beds and the flaps are cut on all it’s sides and undermined. These cuts are enough to raise the flap in a V Y procedure, (in a three dimensional kind of way) and the broader parts of the flaps are lifted and sutured to each other with enough projection to mimic a nipple. The area surrounding the reconstructed nipple is then marked approximately equal to the areola on the opposite side and is excised on which the full thickness graft is carefully sutured and a tie over dressing is given but with an opening for the newly constructed nipple so that it can be observed post-operatively.

Slide21

Slide22

 

Addendum by Prabha Yadav and Saumya Mathews, Tata Memorial Hospital, Mumbai:

Nature’s ability not only to recreate but to exactly replicate living tissue over millions of years boggles the mind though it too is a product of nature.

But hidden within this grand design are also sudden, major and subtle variations. The former leads to a paradigm species shift. The latter is probably a local accident. Anatomists and surgeons have painstakingly identified them over the last two centuries. With the arrival of newer technologies it is easier to pin point these variations ahead of surgery and can aid the surgeon in modifying his plans. The transverse abdominal flap based on the perforators of the deep inferior epigastric artery (DIEPF) is a case in point. The safety zones in this flap can now be ascertained more precisely by computerised tomographic angiography. This can later be confirmed on the table by the naked eye. The DIEPF flap appears now to have become the work horse for reconstruction of the breast and this investigative option would be worthwhile to be noted in this chapter.

April 27, 2017

63. Gynecomastia

Filed under: Chapter 63,Uncategorized — ravinthatte @ 8:56 am

63. Gynecomastia

Idiopathic persistent adolescent mammary hyperplasia of the male breast.

This article was compiled with the help of Dr. R.K.Mishra of Lucknow and Varun Dixit of Mumbai. Both of them are plastic surgeons. They have either published or presented work on this subject with the help of a sizable number of cases.

  1. The slightly long title of this chapter points to the scope of the chapter. The literature reveals several classifications of this condition in which severe forms with more than 500 grams of tissue accompanied by marked ptosis of the breasts are included and are described as grade 4. The treatment of such cases might involve excision of skin and relocating as well as reducing the size of the nipple areola complex. That category is not included in the present chapter and will be covered in another chapter on reduction mammoplasty at a later date.
  2. Mammary hyperplasia can occur immediately after birth in both the male as well as the female offspring because of high levels of maternal circulating estrogens. The condition lasts for as little as a few weeks and resolves spontaneously after the estrogen levels fall. In males, mammary hyperplasia also occurs when the level of circulating testosterone falls and this may occur any time after the age of fifty or even earlier. This condition is no different anatomically from the changes that occur in the adolescent except perhaps in the fact that the fat component of the lesion might be higher and is inevitably associated with skin laxity and excess. Gynecomastia can also be secondary to a variety of causes mainly hormonal dysfunction caused by abnormal secretions of various glands for example the pituitary, the thyroid, the adrenal, as well as the gonads and this might be a part of a syndrome. The condition is also caused by a variety of drugs, and the list is long. Generally speaking, though a physical examination reveals the non- hormonal non- syndromic nature of the condition, it might be prudent to get a basic hormonal assay done if there are signs and symptoms of feminization e.g. gynecoid body shape, absent or minimal facial hair, reduced or absent body hair, effeminate voice etc. and in specific cases even karyotyping to rule out Klinefelter’s syndrome before considering further treatment and a clearance in this regard from a relevant specialist would be ideal prior to surgery.
  3. Pseudo-gynecomastia in which the male breast appears to be enlarged but in fact has little glandular enlargement is usually caused mainly by fatty tissue and might in turn be because of obesity. This is evident when the rest of the body is examined. Losing weight is advised in such cases. This is easier said than done and even if appropriate weight loss takes place its effect on and around the breast mound might not be such as to alter its size and shape adequately enough to allay the patient’s anxiety and this group of patients are also suitable candidates for surgery. In the last quarter of a century a virtual epidemic of morbid obesity seems to have broken out in the more affluent parts of the world. This is evident in India’s cities as well. All manner of specialists are devoted to treating this condition including bariatric surgeons who when they are successful, create a person who resembles an empty oversized bag of skin following what is called as RMWL (rapid massive weight loss). This person could be of either gender and often requires surgery in the area of the breast. That subject too is not covered in this chapter and will be covered later as the blog progresses.
  4. The male breast remains rudimentary through-out life though on extremely rare occasions a male breast can grow not only like a female breast but can also lactate enough to feed a baby. The compiler of these short notes is reminded of a photograph from Bailey and Love’s short practise of surgery, a reliable textbook of the sixties of the last century in which a large man with multiple and enlarged breasts was feeding more than one infant There is no way to know if that individual in the photograph had some hormonal abnormality. The reason the male breast remains rudimentary lies in its structure which has very few ducts and several of them are in the form of solid cords which end blindly. The cords are devoid of lobules or alveoli which are the normal constituents of the glandular tissue in the female breast which are the receptor end organs for the pubertal proliferation induced by hormones. As mentioned earlier it is the transient imbalance or excess of estrogens or alteration in the ratio between the male and female hormones around the pubertal years in boys that causes the proliferation of the rudimentary glandular tissue which results in gynecomastia and at least in some cases this excess persists causing some psychological distress to the adolescent patient (!). Nowadays, a unique pattern of hormonal imbalance is commonly induced by improper and excessive use of steroid / supplements for the purpose of ‘body building’ leading to development of a gynecomastia. The Mechanism is as follows – the exogenously given testosterone supplement suppresses the endogenous secretion of testosterone. Not infrequently, once the exogenous testosterone is withdrawn the endogenous testosterone fails to normalize and results in a relative estrogen excess leading to gynecomastia. This type of gynecomastia can also cause some pain at the beginning. This pain may be persistent and may often be the main complaint and–such cases are usually found to be associated with dense or tough glandular tissue). It is now well documented that the incidence of malignancy in the male breast is not higher in patients (!) with gynecomastia. The indications for surgery usually therefore involve problems of ‘body image’ Not infrequently the severity of the psychological affection is not proportionate to the size of the lesion.
  5. The concept of a ‘Body image’ has come to play a somewhat exaggerated role in the last few decades. When that idea is mixed up with gender identity the mixture can present a formidable problem and the surgeons should be somewhat wary when counselling such patients. The individuals might suffer teasing, are touched inappropriately, are reluctant to participate in body sports and also avoid changing rooms. Their morale may be low and some of them are on the verge of depression Expectations may be quite high and it is important to point out to the patient that removal of the excess tissue is not going to convert him into a male ‘hunk’ and upgrade his existing pectorals. The patient must be informed about the size of the actual glandular tissue that is felt on palpation and that the rest of the enlargement in and around the region of the breast is fatty in nature and if the patient is overweight it would be best for him to reduce weight so that the surgery can become more effective and easier. Generally speaking a more convex nipple areola complex is an indication of a glandular gynecomastia.
  1. More often than not such is the state of the anxiety in the individual’s mind that this advice is rarely followed. Having said that, experientially in the eyes of the compiler of these short notes there might be a tendency in individuals with gynecomastia to have some abnormal proliferation of fat around the glandular enlargement but the literature is silent on whether this too is triggered by the hormonal influence. A modern lifestyle with accompanying caloric excesses also perhaps plays a part in this deposition of fat. Surprisingly few if any surgeons appear to use either an MRI or a CT scan to separately quantify the amount the glandular tissue and fat and seem to rely only on clinical examination.

Slide1

  1. The above narration leads to a discussion as to what a surgeon must do vis-a-vis a normalisation (!) of the area. Reconstruction would be perhaps a wrong word to use in these procedures. The first priority is to as far as possible reduce if not eliminate scarring because a conspicuous scar would be tantamount to letting the cat out of the bag. The curvilinear sub-mammary incision at some distance inferior to the areola is now history and is never employed. For some years now a curved incision at the junction of the areola and the normal skin extending from the nine-o-clock to the three-o-clock position was employed very frequently but its popularity has now receded because it was observed that the scars were more visible as compared to scars of an identical intra-areolar incision.

Slide2

  1. In either case the surgery had a “pin hole” or minimal access character in which extensive undermining of the skin was performed superficial to the lesion in its entirety and then the mass was lifted off the pectoral fascia and was excised in pieces after delivering it through the small incision. Surprisingly very large masses similar to a fairly developed female breast could be delivered through these incisions.

Slide3

  1. This method however had a major drawback with respect to the exact amount of fat which needed to be excised and frequently the post-operative appearance resembled a concave dish sitting on either side of the midline of the chest. The difficulty lay in the nature of the distribution of fat which either clung to the mammary tissue or was distributed unevenly around the hypertrophied breast tissue.
  2. The technique of liposuction in vogue for the last quarter of a century has been a great boon in the surgery for gynecomastia because not only can fat be removed separately from the gland by this technique but as it is being removed the surgeon can inspect the contour of the chest wall intermittently. What is more relevant is that, this removal by liposuction can be performed prior to the excision of the fibro-glandular tissue which then becomes much easier to perform.

Slide4

  1. Here too because the normal male areola and nipple has a somewhat convex appearance it is easier to leave behind a proper amount of glandular tissue (the disc) behind, in front of the backdrop of a chest which is now bereft of excess abnormal fat. Several surgeons now take recourse to an incision across the areola from the nine o clock to the three o clock position and also transect the nipple. The incision is then deepened circumventing the ‘disc tissue’ to be left behind and then excising the rest of the gland.

Slide5

  1. To facilitate this excision a cruciate incision can also be employed which includes the nipple as well resulting in four triangular flaps with their bases towards the periphery of the areola. All these incisions can be closed in one layer with fine sutures and several surgeons opt for the absorbable variety. Dr R.K. Mishra who has contributed to this chapter and whose case reports are reproduced at the end of the chapter performs the glandular excision and extraction by way of a surgical opening only on the top of the nipple.
  2. The endpoint of surgery is a well contoured chest wall anteriorly as well as laterally. In fact, a small concavity is evident subjacent to the areola immediately after surgery. This depression always fills up during the healing process by 4 to 6 weeks after surgery. A customised compressive garment is applied immediately after surgery. This must be worn 24/7 for 4 to 6 weeks after surgery.

Slide6

  1. Generally, it is now accepted that surgery should be undertaken only a year after the lesion appears because the lesion(!) might reduce as hormonal imbalance wanes and also because the patient might be able to adjust to his condition if the swelling does not increase. Ideally it is advisable to perform the procedure between the age of 18-21 years In some cases surgery may be performed earlier if the boys are significantly affected in their minds. However, in such cases the parents must be explained about the possibility of recurrence during the subsequent years of growth. Surgery in older grown-up males up to the age of forty is also now being performed for purely aesthetic reasons and here the selection of cases is easier because the subjects are more mature.
  2. The condition is almost always bilateral and frequently the two sides are neither equal nor symmetrical. Smaller lesions are amenable to surgery under local anaesthesia but the larger ones are not and it is best to impress on the patients that though the incisions are small, in effect a bilateral mastectomy is being performed, leading to a large enclosed dead space and that post-operative reactionary bleeding is possible and to prevent that possibility a tight pressure dressing or garment will be given post operatively. This garment serves several purposes – minimises post-operative swelling / edema, helps to prevent a seroma and facilitates better skin co-option. The surgeon also needs to be extra careful during this type of ‘key’ hole surgery and must ensure an absolute dry bed prior to closure. In the past two decades, the economy of scale has been such that more and more surgeries are being performed on an out-patient ‘day-care’ basis and there is a tendency to discharge the patient early but it must be remembered that liposuction involving large quantities of fat has its own consequences including hypovolemia and electrolyte imbalance and monitoring of the pulse rate as well as blood pressure should be done over several hours prior to discharge though this is rare as the volume of the lipoaspirate  is not very large; never more than 8% of body weight. Electrolyte imbalance often manifests as a change in the sensorium and any unusual pain is usually a tell-tale sign of bleeding with formation of hematoma and this can be diagnosed only by removing the dressing. There should be no sense of shame in re-exploring the wound and should a hematoma be observed the wound should be re-explored, the hematoma evacuated and haemostasis achieved because otherwise the blood clot might increase over a period of time and even if it does not, it might evolve into a seroma which may take a long time to absorb, will need repeated aspirations, ultimately marring the result in that area.  Fat embolism is another dreaded problem of any liposuction procedure. This may manifest in small volume liposuctions as well especially when increased bleeding is encountered during the early stages of the procedure. The patient must also be informed that the pressure dressing will ultimately be replaced by a tight-fitting pressure garment over the chest to help the skin to snugly drape over the recently created surgical hollow. If the cavities created following surgery (the pressure garment and/or dressing not-withstanding) should have a drain through the liposuction site is a matter of individual choice as well as how the case progressed on the table. Dr. R.K. Mishra the senior of the two contributors leaves the liposuction incision open and covers it with a bulky absorbent dressing.
  3. A series of photographs are reproduced below showing the surgical technique as well as some results. In the cases operated by Dr. R.K. Mishra the glandular excision and extraction has been performed by way of an incision on top of the nipple as mentioned in the text. A representative sample of his technique as well as cases are given first followed by cases operated by Varun Dixit who is inclined to use the cruciate incision earlier described in the text

The following pictures are contributed by Dr. R.K. Mishra with his technique in which the top of the nipple is deroofed to approach the mammary gland after liposuction.

Slide7

Slide8

Slide9

The following pictures are contributed by Varun Dixit who is inclined to use the cruciate incision across the areola (the incision is barely 1-2 mm beyond the nipple in all directions and never across the entire areola).

Slide10

April 3, 2017

62. Congenital torticollis (sternomastoid tumour)

Filed under: Chapter 62,Uncategorized — ravinthatte @ 6:14 am

62. Congenital torticollis (sternomastoid tumour)

This chapter was written with help from Rujuta Mehta and Mandar Agashe both paediatric orthopaedic surgeons from Mumbai India. Mandar was Rujuta’s understudy at one time. The anatomical dissections were performed by Chirag Bhansali a post graduate student in plastic surgery at the Lokmanya Tilak hospital in Mumbai.

1.   The sternomastoid muscle arises by way of a sternal as well as a clavicular head and the latter is flatter broader and somewhat aponeurotic while the sternal head is  shaped like a belly The two origins enclose a hollow space which is considered an aesthetic surface landmark. The clavicular head ascends directly to the mastoid bone to which it is attached but on its way, in its middle third, passes behind the sternal head and this arrangement together with it’s dual separate origins, enclosing a fossa, marks it as a spiral cruciate muscle. The muscle lies deep to the platysma in its entirety. This fascio-muscular structure is incised first in order to expose the muscle. The sternal head ascends beyond its main insertion into the mastoid bone onwards onto the nuchal line on the occipital bone of the skull. The mastoid attachment of the muscle lies adjacent to inferior pole of the parotid gland (see figures below paragraph 2). The contraction of this muscle tilts the head to the ipsilateral side and also rotates it to the opposite side resulting in a contralateral upward glance. The most frequently noticed motion brought on by these muscles acting together is the ‘level rotation’ from side to side.

2.   In its lower third the muscle is crossed by the omohyoid muscle on its deeper surface and inferior to this the anterior jugular vein crosses its deep surface which in this area is joined by the clavicular vein but these veins lie superficial to the sterno-hyoid muscle. The external jugular vein crosses the muscle in it’s upper third superficial to it. From here up-to the posterior belly of the digastric the carotid vessels in their sheath lie immediately deep to the sternomastoid . Also at the level of the posterior belly of the diagastric, the spinal accessory nerve enters the muscle from its deep surface, supplies it and exits the muscle in its middle from its posterior border. In cases of a congenital shortening of the muscle, these important anatomical landmarks might be somewhat telescoped on each other but must be remembered to avoid injury to them. For example an injury to the anterior jugular vein can be quite troublesome. When the muscle is released at its insertion from the mastoid bone it is best to release the muscle sub-periosteally to avoid injury to the lower pole of the parotid gland or the accessory nerve which enters the muscle a little lower down.  An unnamed vein crosses the insertion on its superficial surface which too may cause troublesome oozing unless the release is performed sub periosteally.

Slide1

Photoshopped from Gray’s Anatomy

Slide2

Slide3

3.   The condition is almost always unilateral and though a bilateral deformity has been mentioned that condition is probably a generalised shortening of multiple structures in the neck as well as fusion of cervical vertebrae as occurs in such conditions as the Klippel-Feil syndrome.  The incidence of the unilateral condition is about. 3 for every thousand births out of which a small fraction might have other skeletal abnormalities, a dysplasia of the hip being the commonest. A mal-positioning of the head in the uterus particularly in a breech presentation or a vascular insufficiency (intra utero) have been thought to be the commonest causes for this deformity. An unexplained compartment syndrome has also been blamed for its occurrence.  That a hematoma leads to this deformity is not accepted anymore because biopsies have never revealed any traces of hemosiderin. The deformity has also been attributed to birth canal injuries during parturition followed by scarring and here the deformity is strictly not congenital in nature. When the deformity is present at birth it has often been called a sterno-mastoid tumour because it presents like a swelling and in many cases with or without physical therapy the swelling seems to subside leaving behind a tight band of varying breadth in the neck.

4.   The effects of the shortening of the muscle leading to torticollis vary depending on the severity of the shortage. A transient mild condition has been described. Some passive exercises is all that is required in such cases. Here on successively, more severe conditions are visible and can be graded according to an angle between a horizontal line drawn on upper surface of the last cervical vertebra and a line drawn between the two angles of the mandible. This test is rarely done to estimate the severity of the condition but is sometimes used to gauge the correction obtained by surgery. An angle less than five degrees is considered a satisfactory post-operative  result and the residual deformity is assumed to be correctable by subsequent physiotherapy which may be helped on further by either a static or a dynamic one where a screw is employed, on an appliance. While the effects of the deformity on the cervical spine are often visible on an x-ray the effects almost never result in any neurological consequences and in today’s day and age when most deformities get treated prior to puberty, even in the developing countries, it has been observed that the spinal deformation returns to normal.

Slide4

5.   A condition called acute torticollis also occurs following a poorly positioned neck during near comatose sleep usually following drug abuse or after an alcoholic binge. A more frequent occurrence is on account of an inflammatory condition in the vicinity of the muscle or an irritation of a nerve root emerging from the cervical spinal cord frequently due to a prolapsed inter vertebral disc .In both cases the primary condition must be diagnosed and treated

6.   In a majority of cases congenital torticollis is diagnosed by the abnormal position of the neck in early infancy or at birth. Occasionally the condition is diagnosed as a refractory error, noticed in the school which in fact is caused by the abnormal position of the neck. As mentioned above milder versions can be treated by physical therapy alone. In the more severe forms surgery will be needed bearing in mind the secondary changes that might have resulted in the adjoining or deeper tissues following the long standing contracture of the muscle. This mainly includes the deep fascia here in this case the platysma and might rarely involve the carotid sheath which is formed by the deep investing fascia as well as the scalenus anterior muscle or its overlapping fascia (please see figure in para two). Though common wisdom suggests that such secondary contractures are usually amenable to post-operative physical therapy and dynamic splints the difficulties of executing this programme in children must be borne in mind during surgery. There is absolute unanimity however about the need for the release of the deep fascia (the platysma in this instance) in all cases and this usually suffices to correct the deformity but if not, an intra-operative palpation, followed by a judgement on the part of the surgeon has to be relied upon to take a decision, as to whether a surgical release of the scelenus anterior muscle and the carotid sheath is needed. When the deformity is treated by a bipolar approach (please see paragraph 9) in which both the origin and insertion are released some undermining of skin followed by a partial fasciectomy has been advocated for very severe contractures. The literature also mentions a Z plasty on the tendon of the muscle at its origin but this perhaps is rarely practised today.

7.   In many cases a moderate to severe deformity is accompanied by deformation of the face in which the orbital fissure is inclined downwards towards the affected side mainly because of malar hypoplasia and there is a tendency for the skull to be plagiocephalic (flat)in the frontal and occipital regions. Surprisingly these changes may be present at birth. Surprisingly because the growth of the membranous bone around the skull and the face occurs by genetically induced addition of bone as well as by muscular traction during early infancy and childhood. The fact that such changes occur early may mean that there is a syndromic element involved particularly because the area of the face and the neck develop from adjoining arches. On the other hand the absence of a full range of motion in the neck is bound to affect movements of the face in general which too can lead to the bony hypoplasia. Positional flattening (in the supine position) of the occipital as well as the parietal bone is well known and it is likely that in congenital torticollis such flattening is more common due to the contracture of the neck which makes it difficult for the child to  sleep on the side opposite to the side of the deformity. What is remarkable is the desultory attention that has been paid to this subject in the available literature though evidence has been cited to show that the successful treatment of the condition in early childhood arrests the further development of deformation. Also there is very little material available as to if these craniofacial deformities are surgically treated to improve the appearance of the face or the skull in cases where the condition is treated in older children.

8.  The general consensus appears to be inclined to operate on these children at around the age of four years before the child starts formal schooling after some form of physical therapy has been given till then. In the infant, this involves passive stretching and it has been claimed that a large number of children respond to this treatment enough to not require any surgical treatment at all.  Also surgery in early infancy is comparatively difficult on account of the reduced span of the neck and the tissues may have telescoped on each other. In addition, no significant advantage seems to be gained by early surgery and any form of post operative splintage is difficult to maintain at that age. There are several reports of surgery being undertaken as late as twelve years either because the patient came late or (surprisingly) by choice and equally good results have been claimed.

9.   A majority of surgeons opt to release the contracture of the sternomastoid at the lower end at its origin which is the rational thing to do as is done in ischaemic contractures around the elbow (Volkman’s) in which the common flexor origin is released and stripped down beginning with the medial epicondyle or as in an adduction contracture of the thumb in the palm in which the origin of the adductor is stripped of its origin from the metacarpal. Yet there is probably a smaller group of surgeons who continue to employ a bipolar method in which the muscle is stripped from its insertion as well, over the mastoid bone on which it is inserted. Additionally, there is a group which releases the muscle only at its insertion over the mastoid bone. At least some surgeons migrate to the bipolar method due the dissatisfaction of the results of the unipolar method (when the muscle was released at the origin at the lower end). It stands to reason that if the release of the secondarily contracted fascia is to be effective then its release in two areas in a bi-pedicle fashion at the two ends would be more singular because the area of the total contracture is large and vertically disposed. A series comparing the results of the three methods is difficult to collate because exactly similar cases with identical secondary contractures are difficult to assemble.

Slide5

Slide6

Slide7

Slide8

Contributed by Mandar Agashe.

Slide9

Slide10

Contributed by Mandar Agashe

January 20, 2017

Chapter 60. Understanding flaps based on Perforators (Vasculosomes)

Filed under: Chapter 60,Uncategorized — ravinthatte @ 5:47 am

Chapter 60. Understanding flaps based on Perforators (Vasculosomes)
(Addendum to Chapter 59)

This chapter was invited from Adhish Basu, Kolkata, whose work on perforator flaps won the Kilner Essay Award (2016) of the Association of Plastic Surgeons of India. He presents a slightly different view of perforator flaps as compared to the previous chapter.

There has been a long-standing confusion towards naming traditional peninsular-design skin flaps (like the groin flap) as perforator flaps. While harvesting these flaps, the operator takes a leap of faith as the perforators that obviously provide the flap with nourishment essential for it’s survival are not visible! Although not visible, the perforators are present and therefore the flap should be called a “perforator flap”. Unfortunately, flap nomenclature has traditionally been based on flap dissection techniques rather than on their vascular basis. When Fu-Chan Wei et al described their ‘free-style perforator flap from the thigh, the dissection of perforators through the muscle was a requirement to call it a perforator flap.[1] It was actually Ye-Guang Song and co-workers who were the first to describe a perforator flap from the thigh in 1984, years before Isao Koshima described the perforator flaps from the abdomen in 1989.[2][3] The reason why Koshima is often quoted as the first one to describe perforator flaps is because of his description of intramuscular dissection of the pedicle over a long distance.[3] The free-style concept was actually first described by Sipra Asko-Seljavaara in 1983 who proposed an exploratory skin incision for dissection of the perforator around the point where it perforates the fascia.[4] Hence all isolated perforator flaps are actually free-style in concept. The question of whether the tissue characteristics of the donor and recipient match, needs to be addressed by any flap that is harvested, and not necessarily the flap has to be one that has its perforators skeletonized![5]

The vasculosome theory provides a physiological basis for harvesting perforator flaps.[6] (Figure 1) Based on the principles of the vasculosome theory the flaps based on perforator vessels may be classified into three broad categories viz. “isolated” perforator (IP) flaps, “clustered” perforator (CP) flaps and combined perforator flaps.[5] (Figures 2 and 3).

vasculosome-theory-basu-flap-classification-fig-1

vasculosome-theory-basu-flap-classification-fig-2

vasculosome-theory-basu-flap-classification-fig-3

When a single vasculosome is harvested based on dissected and isolated perforator vessels the flap is termed an Isolated perforator flap. (Figure 2) On the other hand when one or more vasculosomes are harvested based on one or more perforators which have neither been dissected nor been isolated, the flap is termed a clustered perforator flap. (Figure 2) Both isolated and clustered perforator flaps have subtypes. While the isolated perforator flaps may be subdivided based on the length of pedicle dissected into long and short types; the clustered perforator flaps may be classified into peninsular (Latin paene = almost and insula = island) and island subtypes. An example of the peninsular clustered perforator flap is the traditional groin flap; whereas examples of the island clustered perforator flap are Behan’s keystone design island flap and the radial forearm flap (where multiple forearm vasculosomes are supplied by a long source vessel, the radial artery). The pectoralis major musculocutaneous flap when harvested as a true island flap is also an example of an island clustered perforator flap, the muscle mass being incidentally included in the flap.

If more than one vasculosome is individually harvested on isolated perforators but are eventually joined with a single source vessel, these flaps are termed chimeric perforator flaps. (Figure 3) When a flap has more than one vasculosome included with two separate feeding perforators, the flap is termed a conjoined perforator flap (previously termed Siamese flaps). (figure 3) The latter requires two sets of feeder vessels for complete survival of the flap. Peninsular clustered perforator flaps which require arterial supercharging or turbocharging for complete survival, are basically conjoined flaps.[5]

References

  1. Wei FC, Mardini S. Free-style free flaps. Plast Reconstr Surg 2004;114(4):910–916
  2. Song YG, Chen GZ, Song YL. The free thigh flap: a new free flap concept based on the septocutaneous artery. Br J Plast Surg. 1984 Apr;37(2):149-59.
  3. Koshima I, Soeda S. Inferior epigastric artery skin flaps without rectus abdominis muscle. Br J Plast Surg 1989;42(6):645–648
  4. Asko-Seljavaara S. Free style free flaps. In: Programs and Abstracts of the Seventh Congress of the International Society of Reconstructive Microsurgery. New York, NY; 1983
  5. Basu A. Classification of flaps and application of the concept of vascular territories. In Textbook of plastic, reconstructive and aesthetic surgery, Edition: 1, Chapter: 5, Publisher: Thieme, Editors: Karoon Agrawal, 2016, pp.93 – 120
  6. Basu A. The vasculosome theory. Plast Reconstr Surg 2015; 135(2):449e–451e

November 14, 2016

59. Understanding flaps based on Perforators

Filed under: Chapter 59,Uncategorized — ravinthatte @ 9:04 am

This small chapter is included in this blog to acquaint the readers with nomenclature of  perforator based flaps. To that end the compiler of this blog wrote to Sameer Kumta and Leena Jain two leading microvascular surgeons in private practice in Mumbai India and the following communication was sent to them.

The human circulatory system being centrifugal and because the integument is the body’s outermost layer the vessels that supply it need perforce to pierce fascial envelopes to supply and drain it. The word perforator was majorly used by Ian Taylor the well known plastic surgeon from Australia whose voluminous work was published in the late eighties and nineties, mainly in the British Journal of Plastic Surgery and involved a very large number of cadaveric dissections. These dissections involved the vascular network surrounding the neural network and it was he who conceptualised the idea of an angiosome to define territories of vascular supply based on independent perforator vessels.

The word ‘envelopes’ at the beginning of the preceding paragraph is used in the plural because fascia is present in multiple planes in the body. For example, it envelopes the arteries themselves and is also present as an inter-muscular septum as well as an independent entity which encases the muscle (perimyceum). The fascia is also present in the subcutaneous plane through which the vessels pass to ultimately supply the skin. The question that needs to be clarified is at what level does a vessel come to be called as a perforator. For example the historic Sushruta flap or the forehead flap is now known to be supplied by the supra-trochlear vessel which penetrates the local deep fascia after traversing a bony gutter in the orbit to supply the skin over a large area of the forehead. Could this flap then be called a perforator flap because the concerned vessel pierces the local deep fascia? A similar question can be posed about the well-known ‘groin’ flap based on the superficial external iliac artery. This vessel is a branch of the femoral artery and is termed as a direct cutaneous artery in the existing classification though it has pierced  the femoral sheath which in fact is a condensed form  of the regional deep fascia and what is more a flap is now based on one of its very tiny branches which passes through the subcutaneous tissue to supply a sizable area of skin and can be transferred by way of a micro-vascular transfer. Is this flap a perforator flap? The reply of doctors Kumta and Jain to this communication by the compiler of these short notes is reproduced below. The relevant diagrams were drawn jointly by the compiler and the two expert contributors.

Introduction

Koshima and Soeda in 1989 first described perforator flaps to differentiate an adipocutaneous flap from the conventional fasciocutaneous flaps to highlight the fact that the supra and subfascial plexus were not essential for a flap’s survival. With over 400 perforators more than 0.5 mm in diameter being available across the body, any part of the body can be thus considered as a potential perforator flap donor site, in line with the principle of a free-style perforator flap. This march from conventional flaps to ‘free style’ flap has been revolutionary due to the multiplicity of donor sites that can be harvested in various parts of the body.

To begin with the definition; a perforator flap is one that receives its blood supply from a fascia-perforating vessel whether directly perforating or indirectly perforating it after traversing the muscle or the intermuscular septum. To understand the basic course of a perforator, Werner Spalteholz (1893) has classified them into a direct or a pure artery that directly enters the skin (direct cutaneous perforatorDCp) and an indirect or impure artery that penetrates the muscle / septum and then supplies the skin (musculocutaneous perforator –  MCp and septocutaneous perforatorSCp). This course in practical terms determines  whether or not intramuscular dissection would be required while harvesting a particular perforator flap.

Nomenclature

Newer perforator flaps continue to be described; however there is no uniform anatomical nomenclature of perforator flaps.  The basic requirements to standardise a nomenclature are:

  1. Should be simple to understand and reproducible by any micro-surgeon
  2. Should be anatomically sound
    • define the source vessel (vascular anatomy)
    • define the anatomic muscle dissected if any (surgical anatomy)
    • define the type of perforator (perforator anatomy)
  1. Should be clinically significant in stating whether superfine micro-vascular anastomosis  is required or not.

According to the Gent consensus, a perforator flap should be named after the nutrient artery or vessels and not after the underlying muscle. If there is a potential to harvest multiple perforator flaps from one vessel, the name of each flap should be based on its anatomical region or muscle. For example, the nutrient vessel [lateral circumflex femoral artery (LCFA)] plus the muscle name (vastus – lateralis) yields the flap name, LCFAP-vl. This classification does not however, define the type of perforator that has been dissected- septocutaneous / musculocutaneous and does not mention the level of dissection – perforator level/ source vessel level.

Sinna et al, proposed the following modifications to the above nomenclature:

At least three elements must be accurately described.

  1. The first term specifies the name of the proximal vessel, as suggested by Hallock.
  2. The second term defines the extent of vascular dissection, as suggested by Kim.
  3. The third term identifies the muscle in addition to the type of perforator (a musculocutaneous, septocutaneous, or direct cutaneous perforator), characterized in the Gent consensus.

flaps-perforators

J T Kim, provides an anatomical classification system which signifies the course of perforator, its source vessel and the muscle being traversed if any.

A: DIVISIONS OF NOMENCLATURE

Perforator flaps can be categorized into :

  1. When based on DCp/ SCp, it is named according to the proximal vessel name.
  2. When based on MCp, it is named according to the muscle it perforates.
  3. Whether the proximal source vessel is harvested or dissection is stopped at perforator level itself would indicate the level of anastomosis that is at ‘perforator level’ or ‘source vessel’ level; the former is technically superior as it needs super microsurgical anastomosis. This forms the basis of nomenclature of the flap whether it is a perforator based flap (anastomosis at perforator level) or a perforator flap (anastomosis at  source vessel level).

B: BASIS OF NOMENCLATURE

DCp is the perforator sprouting from the proximal vessel to dermis without traversing the muscle or deep fascia, and mostly found in face, perineum and so on.

SCp is the one piercing the intermuscular septum

MCp, is one piercing the muscle and requires intramuscular dissection of the perforator.

C: APPLICATION OF NOMENCLATURE

  1. LATERAL THORACIC REGION

In accordance with Kim’s classification, flaps from the lateral thoracic region could thus be described and comprehended in the following manner:

“Latissimus dorsi perforator-based flap”: based on a musculocutaneous perforator and dissection stopped at the level of perforator itself.

“Latissimus dorsi perforator flap”: based on a musculocutaneous perforator and dissection done till the source vessel.

“Thoracodorsal perforator based flap”: based on a septocutaneous perforator and dissection stopped at the level of perforator itself, no dissection of the main proximal vessel.

“Thoracodorsal perforator flap”: based on a septocutaneous perforator, dissection done till source vessel.

“Lateral thoracic perforator flap”: based on a direct cutaneous perforator from the lateral thoracic artery, dissection is done till the proximal artery.

Figures below first show the basic design of the branches that ensue from the femoral artery. The wonder that is natural symmetry, means that the same figure can be used to describe the arteries around the shoulder or around the lateral thoracic region by changing the names of the vessels. Nomenclature of perforator flaps harvested from the lateral thoracic region; as well as flaps based on the femoral system are also included in the figures.

1_f-cutaneous-design

2_f-cutaneous-design

3_f-cutaneous-design

  1. LOWER LIMB

In the thigh, the anterolateral thigh flap can be elevated based on SCp or MCp:

‘vastus lateralis perforator flap’ based on MCp, dissection done till source vessel

‘vastus lateralis perforator based flap’ based on MCp, dissection stopped at perforator level

‘lateral circumflex femoral perforator flap’: based on SCp, dissection done till source vessel

‘lateral circumflex femoral perforator based flap’: based on SCp with dissection stopped at perforator level

  1. UPPER LIMB

Similarly, in the upper limb, flaps can be described easily and with uniformity.

‘radial perforator flap’, based on SCp from radial artery, dissection till source vessel

‘flexor carpi radialis perforator flap’: based on MCp perforating the flexor carpi radialis, dissection till source vessel

CONCLUSION

  1. New Nomenclature of Perforator Flap: scientific, accurate, anatomical, consistent and simple.
  2. Perforator flaps:
  • MCp: name of muscle + perforator flap
  • SCp / DCp: name of source artery + perforator flap
  1. Perforator based flap: no sacrifice of source artery, suffix of anatomic direction or area
  • MCp: name of muscle + perforator based flap
  • SCp / DCp: name of source artery + perforator based flap

The above nomenclature proposed by Kim is easy to follow and can be comprehended by surgeons across the globe. Uniformity in nomenclature of perforator flaps cannot be over- emphasized as perforator flaps are the order of the day in reconstructive surgery.

SUGGESTED READING

  1. Koshima I, Soeda S. Inferior epigastric artery skin flaps without rectus abdominis muscle. Br J Plast Surg. 1989;42:645–648.
  1. Taylor GI. The angiosomes of the body and their supply to perforator flaps. Clin Plast Surg. 2003;30:331–342
  1. Wei FC, Mardini S. Free-style free flaps. Plast Reconstr Surg. 2004;114:910–916
  1. Blondeel PN, Van Landuyt KH, Monstrey SJ, et al. The “Gent” consensus on perforator flap terminology: Preliminary definitions. Plast Reconstr Surg. 2003;112:1378–1383; discussion 1384–1387.
  1. Sinna R, et al. What Should Define a “Perforator Flap”? Plastic and Reconstructive Surgery December 2010.vol 126;6: 2258-2263
  1. Kim JT. New nomenclature concept of perforator flap. Br J Plast Surg. 2005;58:431–440.
Next Page »

Blog at WordPress.com.