THE THROMBOSED PROSTHETIC GRAFT IS A RISK FOR INFECTION OF AN ADJACENT GRAFT

BACKGROUND: A bland thrombosed graft may be more susceptible to the fu ture risk of infection than a patent graft, Once infected, that graft can threaten other patent grafts, Therefore, the purpose of the follow ing study was to assess the role a thrombosed graft might play in infe ction of contiguous patent bypasses. METHODS: From 1990, a retrospecti ve review was performed using the operative and medical records of cas es in which a prosthetic graft infection was identified arising in ass ociation with an adjacent thrombosed graft. RESULTS: A total of 22 cas es of prosthetic arterial bypass infection were treated at our institu tion from January 1990 through September 1995. Of these, 7 (32%) were identified by the operative report as arising in a thrombosed prosthet ic graft and spreading to an attached or adjacent patent prosthetic gr aft, All patients had multiple bypasses prior to infection, mean 5.4 /- .75 (range 3 to 8). All thrombosed infected grafts were infrainguin al polytetrafluoroethylene (PTFE) for limb salvage: 6 femoralpopliteal and 1 femorotibial, Mean interval time between placement of the prima rily infected graft and removal was 14.6 +/- 6.7 months (range 1 to 53 ). The secondarily infected patent bypasses were inflow procedures to the same limb in 6 cases: 1 aortofemoral, 2 ileofemoral, 2 axillofemor al, and 1 femoral femoral graft. The thrombosed infrainguinal bypass w as directly attached to the secondarily infected bypass in 5 cases and near but not attached in 1 case. One secondarily infected prosthetic graft was a femoraldistal bypass placed adjacent to the thrombosed gra ft, Four patients had above-knee amputations with a clinically bland g raft divided at the time of amputation, In these 4 patients and 2 addi tional cases, wet gangrene or infection was present in the distal extr emity prior to the development of prosthetic graft infection, At the p oint that infection became clinically apparent, the thrombosed graft w as removed in all cases and the secondarily infected graft was removed in 4 of 7 cases. Overall mortality was 57%. CONCLUSIONS: A thrombosed prosthetic graft near a patent prosthetic bypass may become secondari ly infected and threaten the patent graft, We recommend total removal of any thrombosed prosthetic graft in proximity to a patent prosthetic bypass when the risk of infection is high or at the time of subsequen t amputation for gangrene.