Coverage of Soft Tissue Defects in the Management of Infected Vascular Grafts

Abstract

Infection in vascular grafts is considered to be a disastrous complication of vascular surge•y. Not only the limb of the patient may be in danger as a consequence of this complication, but also his life. Although the incidence of vascular graft infection in literature is not high (I% to 6 %) yet, its complications are devastating. Infection of the native vessels results in weakening of the vessel wall and dismption of the anastomosis. The inflammatory process results in the •precipitation of aneurysmal dilatation, haemorrhage and fistula formation. eath ay ccur ue o verwhelming sepsis or haemonhage. Bacterial infection accounts for the maj01ity of vascular graft infection. Less frequently fungi (Candida albicans, aspergillus), mycoplasma and mycobacterium have also been identified. In recent years, there has been a gradual change in infection pattern. In earlier studies, Staphylococcus aureus accounted for 50% of all vascular graft infections. More recently this incidence as iminished and Staphylococcus epidermidis now accounts for 60% of all graft infections Infections in arterial grafts were classified originally by Szilagyi et al.in 1972 into three grades: grade I, infection extending only to the dermal level; grade ll, infection extending into subcutaneous tissue not sU!Tounding the graft; and grade III, infection SU!Tounding and in contact ith he raft. he reatrnent f Szilagyi grade I and II infections involving only skin or subcutaneous tissue can be managed easily with local wound care and delayed closure or skin grafting. On reviewing the literature it was noted that vascular graft infection is more common in prosthetic grafts as compared with autogenous grafts, I.9% versus 0.4% in one study. Also the inguinal region was the most common site of vascular graft infection compared with other regions, 3.0% versus 0.7%, as it is a relatively (dirty) area. It's close proximity to the perineum and the redundant folds of skin considerably increase the colonisation of the area with skin pathogens. Prosthetic grafts are more prone to infection as they act as any foreign body and harbour organisms within the interstices of the graft. The type of the prosthetic graft also affects the incidence of infection as for example, the bacterial adherence to dacron grafts is I 0 - I 00 times greater than PTFE grafts.