Short Notes in Plastic Surgery

September 30, 2011

Treatment of Wounds – Repair and Reconstruction (Part 2)

Filed under: Chapter 15 — mthatte @ 4:18 am

1. Notwithstanding what has been said in the last paragraph of part 1 of this chapter there will be situations where a flap can save a life. example,
a. When a part of the brain bulges through a defect in the skull and is oedematous and does not have any skin or meningeal cover, the situation can lead to a serious infection followed by a fatal outcome. An oedematous brain is best not covered by anything rigid (bone or a metal mesh) and the situation demands a flap cover preferably from the adjacent scalp if available or by a free flap.
b. An exposed lung or heart with injuries to ribs with loss of skin and paradoxical respiration needs a flap cover after the ribs are stabilized. This restores the pleural space and averts further dire complications. A latissimus dorsi flap from the same side is a convenient option.

An example of a lateral chest wall defect including loss of bone treated with a local latissimus dorsi flap. This case is not traumatic in origin but the photographs are included because an identical post-traumatic situation will need a similar cover.

Photographs courtesy: Parag Sahasrabudhe from Pune.
c. After repair of major vessels for e.g. the carotids following gunshot wounds where the repair is done by direct suturing, vein grafts or a prosthetic graft but where the skin is shattered, contaminated and devitalized, a flap will help heal the vascular repair, restore circulation and reduce the overall chances of a blowout. A delto-pectoral flap can be a good choice for this site.
2. There will be situations where major post-surgical complications will threaten life or a repaired part. Here flaps can be of great help. examples,
a. A sternal dehiscence after a sternotomy for cardiac surgery can threaten life or mar the result of surgery. The condition of the patient permitting, a quick re-fixation of the sternum with resuturing of skin is the first option. But should the skin be suspect, its excision followed by a pectoralis major musculocutaneous flap based on a branch of the axillary artery away from the zone of sternal separation can avoid a catastrophe.

A. Infected sternal dehisons following open heart surgery. B. Debrided tissue including ends of ribs and cartilage. C. Indigenous VAC appliance has been applied. D. Pectoralis major flap can be seen moving in to the wound. Notice near the shoulder its attachment has been cut from the humerus yet preserving its blood supply which enters it about its middle. E. For the lower part of the defect the omentum has been brought up from the abdomen. F. The infected wound is now fully treated with vascularised tissue. G. Final result several weeks later. Skin has been sutured primarily.

Photographs courtesy: Parag Sahasrabudhe from Pune.

b. A repair of a major artery with a vein graft or a prosthetic graft as a planned procedure (for e.g. in the groin, thigh, popliteal fossa, neck or the axilla) can undergo an early or late complication because of infection and the skin might give way, become oedematous and unreliable. A local flap based on vessel or vessels arising proximal to the site of repair can secure the wound and give some chance for the vascular repair to succeed and save a limb. In the groin when the femoral artery is involved, a flap based on the deep inferior epigastric artery, a branch of the external iliac will be a good choice. As one goes lower down in the inferior extremity such flaps might become more difficult to find and release incisions on either side of the wound up to and into the fascia may allow a satisfactory closure of the wound.
c. When a major implant in the joint gets exposed post operatively, it’s only chance, if any, for any long term trouble free retention is if a flap is used to cover it quickly. Almost always, secondary suturing of such a wound will not help. Here too a local flap can be useful. For example, a gastrocnemius muscle flap for an exposed implant in the knee joint.
Comment: The plastic surgeon should be aware that most of the patients in this group may be on anti-coagulants.
3. With the advent of free flaps in patients who are stable and there is time to deliberate and time a flap, the choices have grown manifold. The old dictum that a local flap when feasible should be preferred over a distant flap (free or otherwise) now really holds true only in the area of the face and the scalp, because the nature of the facial skin with or without hair cannot be matched by any distant flap and in the scalp hair is of paramount importance. In both instances therefore the best use must be made of the available skin and this is where tissue expanders are most frequently used.
Comment: This is also the genesis of a full face transplant.
4. For other reasons for e.g. in reconstruction of the breast, the use of a latissimus dorsi flap or a lower abdominal flap based on the rectus muscle have been abandoned to a great extent because of scarring and the need to bolster the abdominal wall with a mesh where the rectus is used. Both flaps mentioned above are adjacent if not strictly local flaps. Instead the bulk of the lower abdomen together with the overlying skin based on major perforators of the inferior epigastric system are harvested as a free flap to reconstruct the breast.
5. Generally any local flap in the extremity means additional scarring in visible parts. Local flaps based on perforators are ingenious but patients might demand a free flap (could be based on a perforator) from a generally hidden part of the body.
6. In an athlete a local gastrocnemius flap for a tibial cover may not be fair to his future rehabilitation and his request for a distant free flap from a non-functioning area would then be legitimate.
Comment:
Microvascular free flaps are now being done routinely across specialities and the time may not be far when robots will be used for microvascular repair, such repairs might be done by technicians and lastly if a coronary vessel can be dilated and its patency maintained by a stent, surely such an innovation may be feasible in free flaps.
7. The introduction of free flaps has meant that more reliable, one stage sensate flaps can now be performed. While theoretically they should be better, at least from the point of view of protective sensations (if not finer sensory modalities), the jury is still out on what is the best treatment for e.g. in a denuded heel, the commonest site for which a sensate flap is used. Ideally the medial plantar flap (based on a branch of the posterior tibial artery and containing the medial plantar nerve) from the concavity of the middle third of the foot should be transposed to resurface the heel when such skin is available and when most of the soft tissue over the heel is missing and bone is exposed. But this might not always be possible. The choice is then between a staged cross leg flap, carrying the sural nerve, a free musculocutaneous flap, a free muscle flap covered with a skin graft or even a skin graft alone when a thin layer of viable soft tissue over the bone is nursed with careful dressing till granulation tissue appears. Long follow-ups with all the above methods have shown some success. The one common feature associated with all these flaps is hypertrophic cornification at the junction of the flap and the normal skin. This occurs very rarely with a medial plantar flap which remains the first choice if available. This cornified tissue needs to be carefully excised from time to time.
Comment: In the past a cross-finger flap was the commonest procedure performed for loss of skin and soft tissue in the fingers. They are not sensate flaps. Yet they almost never show any ulceration even in manual workers.
8. The choice particularly of a free flap certainly depends upon to a great extent on what flap the surgeon is most familiar with. Most surgeons will develop expertise with three or four types of flaps. Bulk is always an issue. Sometimes it is needed to fill a space or a cavity in the bone and at other times a bulky flap is avoided to prevent an ugly lump. On the subject of healing of infected cavities, though there have been papers on comparison of random pattern flaps and free muscle flaps in animals, showing the superiority of free muscle flaps; no human trials are available because they are not possible. In any event random flaps are now rarely done and it seems unlikely that a fasciocutaneous flap will have a dramatically lower blood flow than a muscle flap. Traditional anecdotal wisdom for whatever it is worth seems reluctant to divide flaps as superior or inferior in its healing power. A flap that succeeds fully is always a good flap and only good can come out of it.

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Treatment of Wounds – Repair and Reconstruction (Part 1)

Filed under: Chapter 15 — mthatte @ 4:17 am

1. A clean incised wound should be closed as soon as possible after irrigation with saline or a proprietary anti-bacterial solution.
2. A contused, lacerated wound needs a sharp, adequate excision of its edges prior to closure because the contused skin might have been devitalized.
3. Except in very superficial wounds dermal approximation with a durable suture (with a life of three to six months) helps prevent a broad scar and a good dermal opposition means the outer sutures can be removed early.
Comments:
a) The introduction of biological glue and of sterile strips applied across wounds have changed the way the outer layer of the wounds are treated.
b) The introduction of staples in closure of surgical wounds including for flaps after they have been set into defects has reduced operating time and surprisingly crude though the staples might look, the incidence of cross-hatch marks has been almost completely eliminated. The staples do what a ‘she cat’ does to her kitten as she carries them with her teeth. The staples hold the skin at some distance from the wound without puncturing it to any appreciable depth.
c) When wounds occur in unfavourable directions i.e. across Langer’s lines they are usually closed without any primary re-adjustment of the suture line e.g. by a z-plasty, indicating that conspicuous scars are not inevitable in such a situation.
d) Superficial burn wounds heal splendidly with a variety of proprietary dermal substitutes. However when burns occur around fingers in children, when it becomes difficult to wrap the dermal substitute around them, a dressing material dipped in an antibacterial solution wrapped around the fingers secured with a dry, firm bandage can be left alone for several days till it falls off by itself when it becomes loose.
4. In large wounds where the patient is brought in a critical condition, the treatment of the affected systems takes precedence. Cardiorespiratory resuscitation, securing of an airway, treatment of sucking wounds in the chest and volume replacement begin first. If the wound is bleeding, pressure or ligatures or in cases of lacerations of major vessels, application of atraumatic clamps, removal of mangled, crushed and irreparable parts of the limbs is all that should be done as resuscitation begins. Fractures in major bones are assessed, splinted and a plan for their fixation charted out.
5. Once the patients start getting stablised, the wounds are inspected in some detail, repair of major vessels might have to be performed quickly if the viability of the limbs is threatened. If a formal secure skin cover over these vascular repairs is not feasible, local soft tissue or adjoining muscles are used to cover the repair as a temporary measure. Surface cultures, or cultures from dead tissue are sent, antibiotics are used in consultation with other specialists and debridement can begin.
6. Debridement is an artful craft where the cutting instrument must remain within the obviously dead tissue and progress is then made towards what is certainly normal and then stopped when there is evidence of some bleeding. A temptation to chop off tissue en masse is avoided. Serial debridement is always preferred to avoid any excess and also because, as the wound evolves, more dead tissue becomes apparent. Bed sores in acutely ill patients should not be attacked surgically and should be dressed till their full extent is realized.
7. At this stage if there are fractures, they will be stabilized if the patient’s condition permits and the plastic surgeon hopefully should participate in the discussion as to the nature of stabilization because then plans can be made for a flap cover.
8. Wounds that will need skin cover belong to three categories. First, a clean wound in a stable patient which can be covered soon after admission (within first 48 hours). In the second category, a similar wound in a patient who remains critical but stable e.g. on a respirator and a vasopressor drip, is a matter of judgment, choice and certain philosophy. In most units now skin cover is achieved in order to close the wound and reduce any burden that the wound may have on systemic recovery. This can be done with regional blocks or with infiltration of a large dilute solution of local anaesthetics for surface analgesia and can be done in stages over days. But if this is difficult, homografts are applied to achieve the same result to temporarily tide over the situation. In the third category, the wound is dirty, continues to undergo necrosis in its bed and the situation may or may not be complicated by the general condition of the patient.
9. Under these circumstances,
a. The wound must be inspected at least once a day when debridement of dead tissue is undertaken
b. Irrigation should be done with saline or with a proprietary antibacterial compound after instillation of hydrogen peroxide
c. In limbs a simple air pump can be used to create bubbles in an antibacterial solution in a bucket and the limb is immersed in the bucket for up to half an hour, which will help in giving painless, gentle lavage and reduce the bacterial load.
d. A forceful, power driven jet lavage system is now available to clean wounds but it can be used only under anaesthesia.
e. Hyperbaric oxygen will help wounds not only by increasing cutaneous oxygen saturation but is known to help critically ill patients in general.
f. Even in sick patients, suction appliances can be used on any part of the body to clean up the wounds without in any way interfering with the measures that are taken to stabilize patients.
g. The Edinburgh University solution, Eusol, is still used and has had several proprietary substitutes including a solution in which oxygen has been forcibly pumped (short shelf life) but this solution has had its marketing ups and downs.
h. Enzymatic preparations which dissolve dead tissue are available as ointments or in proprietary dressings but have not been fully proved as effective in cleaning large wounds.
i. Some wounds which appear indolent in spite of all the above can improve with tangential excision if some form of analgesic and short acting anesthetic is permitted even if the patient is on a respirator or on dialysis.
10. The improvement in the wound is also greatly dependent on the condition of the patient. For example, a patient with a major brain injury who is sustained on a respirator, a patient who has undergone a major abdominal surgery involving for example a liver resection or a major bowel resection followed by an ileus, or has multiple organ failure as a result of an untreated hypovolemic shock in the initial phase are poor candidates for any improvement of their wounds. It is best that nothing adventurous is done on these wounds under these circumstances. Here expensive biological dressings are a waste of money and effort during what has been described as the catabolic phase of the wound and these applications are just devoured by the multiplying bacteria that grow in the wound. Ordinary dressings will do equally well.
11. This chapter deals mainly with preparation for split skin cover in large wounds. Any situation where two or three areas require a flap, in one or both limbs or other parts of the body, must wait for some time for final treatment. To give an example, a large defect over the lower femur, a repaired popliteal artery, an exposed knee joint together with an exposed muscle mass in the calf and exposed tarsal bones will classically need multiple flap covers but here prudence will be needed because the procedures might destabilize the patient. Each case is dealt as a problem in itself.

Each individual case however must be judged on its own merit. In this case an obese patient was transferred secondarily to a speciality hospital following a vehicular accident and was running fever and had critical injuries over the tendo-achilles and the calcaneus and a part of the heel was exposed which required flap cover. After stabilising the patient the critical area – above left and middle, was covered with a free anterio-lateral thigh flap from the opposite limb – upper right, and then the wound on the front of the foot was allowed to improve – below left and then split skin grafted – middle and right below. Photograph courtesy: Parag Sahasrabuddhe, Pune.

12. There are two parts of the body where non-biological substitutes are useful and can save life where a flap is needed but is not feasible. In the anterior abdomen a large defect with bowel exposed can be temporarily sealed by a sheet made of polytetrafluoroethylene (PTFE), which then can be dressed till granulation can grow from the sides. An ordinary polyethylene sheet covered with a vaseline gauze and dressings, though inferior in quality, has been used with similar results. In the skull the loss of bone and scalp over a large area with the brain exposed can be covered with a proprietary dural substitute and the bony defect can be temporarily obliterated with a titanium net or a special cement, measured and moulded and then fixed to the rest of the bone with wires.
13. What flows from the above points is that decisions made in the treatment of large wounds need to be deliberated. The deliberation more often than not has to be conducted between various specialists. When major flaps are needed in physiologically unstable patients, they are at best left to a later date by when the patient will be in a position to undergo surgery under adequate anaesthesia. However split skin cover will have a stabilizing effect on the patient, and can be performed relatively quickly and easily.

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