The incidence of prosthetic graft infection (PGI) ranges from 1 – 6% .Infected Aorto-iliac or Aorto-femoral bypass carries a mortality of 25 – 75%. Infected distal vascular bypasses have an amputation rate of 8 – 52% .The Traditional Management of PGI consisted of graft excision, and performing an Extra-anatomical Bypass. Such treatment carries a high mortality and morbidity rates in the form of blowout of the native artery and thrombosis of the extra-anatomical bypass.
Wound debridment, with Graft preservation and wound healing by secondary intention were alternative measures to this technique. However wound healing is protracted, costs are increased, and the rate of thrombosis, hemorrhage, and super infection are still high.
Wound excision with Graft Salvage and Muscle Flaps transposition was described with resulting decreased mortality and morbidity rates. The advantage of muscle flap coverage includes; increased local tissue oxygen tension, enhancing leukocyte function and phagocytic activity. Wound bacterial counts were found to be affected with increased antibiotics delivery and elimination of the dead space.
Materials & Methods:
Seventeen patient underwent muscle flap coverage of infected and/or exposed vascular grafts .Data was collected retrospectively and included Risk factors for poor wound healing , Initial bypass operation, Type of prosthetic graft . Interval between initial bypass and diagnosis of exposure or infection, Organism(s) cultured from infected grafts. Wound closure technique (initial vs delayed), graft excision versus graft salvage, type of flap used for reconstruction, intra-operative limb loss. Length of hospital stay, length of ICU stay and subsequent limb loss and mortality rates.
The General principles of management consisted of Aggressive wound debridment and irrigation, followed by the mobilization of muscle flap. The choice of excision or salvage of graft was made in a nonrandom fashion by the attending surgeon according to the extent of infection and peri -graft involvement, the presence or absence of sepsis, and the patency of the graft.
Most patients had several (range 1 to 12; mean 5.6) significant comorbidities.Patients ranged in age from 39 to 72 (mean 62) with 12 men and 5 women. In total 22 flaps were performed on 17 patients. (Twelve sartorius, five rectus abdominus, two recti femoris and three gracilis muscle flaps, were performed.)
The interval from initial bypass operation to diagnosis of exposure or infection ranged from 7 to 2372 days (mean 371 days.)Limb salvage rate for salvaged grafts (n=7) in our series is 100%. Excised grafts (N=10): Two had Intraoperative limb loss, five suffered subsequent limb loss, and four patients had no limb loss. (40 % limb salvage rate).Days of hospitalization ranged from 9 to 36 days (mean 20 days.) ICU stays ranged from 0 to 14 days (mean 2 days.) .A range of one to five organisms were isolated from each patient, three patients had negative culture results. Most patients were positive for gram positive organisms.
The use of muscle flaps in the salvage of infected prosthetic grafts is a logical extension of the use of muscle flaps in other areas e.g. Infected Sternum, Empyema. In our small series of 17 patients the limb salvage rate varied between (40-100 %). Muscle flaps could still be a valid option in the management of the difficult problem of infected vascular grafts.