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.

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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.

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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

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