Compromised Failing Skin Grafts And Flaps

Complications may arise in both kinds of transplanted tissues resulting in partial or total loss of graft or flap.

The presence of doubtful viability tissue is described as compromised. The term failure is mostly related to technical errors during the perioperative period.

Many factors may contribute in order for a transplanted tissue to become compromised.

Causes of graft complications beyond the technical surgical problems are an improper host wound bed due to hypoxia or infection and lack of new tissue development.

In compromised flaps the contributing factors are: ischemia - hypoxia, edema, arterial vasospasm, arterial or venous occlusion, congestion and dehiscence or infection.

A factor of major importance is also the reperfusion injury syndrome when re-establishment of circulation follows prolonged tissular hypoxia as in complicated free flaps.

Patents health factors like age, smoking, systemic disease and/or relative therapy may interfere with the flap prognosis.

Clinical evaluation is of major importance and is tested according to the flap condition taking into account flaps characteristics like color, temperature, capillary fill up and bleeding.

The appearance of cyanotic color in graft is related with delayed revascularization and hypoxia, white color with lack of blood supply and red color with presence of infection.

Follow up of the flap "take" is critical for the first 48 hrs. Observation of the flap color may determine the leading factor of the complication.

The primary cause of flap demise is not an inadequate arterial inflow but rather a venous insufficiency through a compromise venous outflow4. Clinically flap is edematous, colored deep purple or dark blue, (in total venous occlusion) capillary refill is missing and the flap temperature is low.

Assessment of possible compression in grafted tissue is necessary to investigate the presence of tight sutures, hematoma, twisting / kinking of vascular pedicle or venous thrombosis.

Recognition of venous hypertension is very crucial as venous drainage occlusion is much more deleterious for flaps survival judged against low arterial inflow2.

Proper surgical intervention (decompression, medicinal / chemical leeching) must be performed soon.

Arterial insufficiency is related to a pale color, deprived capillary refill, low temperature and lack of pinprick bleeding. The presence of edema, hematoma, kinked pedicle or vasospasm are routinely responsible for low blood flow.

Vasospasm may occur intraoperatively in arterial anastomosis following free tissue transplant or later, (48 hrs) ensuing pathogenesis of thrombosis. Surgical investigation has to be performed on time for the restoration of arterial inflow.

Transcutaneous oxygen pressure (TcPO2), tissular pH, photoplethysmograpphy, laser Doppler, oxymetry and radioisotopic techniques are among the methods for prognosis of objective flap judgement6.

A variety of conservative complementary treatments is proposed according to the cause of the compromised tissue including vasodilators, pentoxiphylline, dextranes, radicals scavengers, fibrinolytics, medicinal or chemical leeching and hyperbaric oxygen therapy (HBO).

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