Purpose: Bacterial biofilm infections of vascular prostheses are characterized by an absence of systemic sepsis, a fluid-filled cavity surrounding the graft, a draining sinus tract, and microorganisms that must be removed from the fabric prosthesis for bacterial culture.
Methods: Since 1987 we have treated 20 infected grafts with prosthetic excision and in situ replacement in 14 men and 6 women. The time from initial graft implantation to diagnosis of graft infection ranged from 3 months to 14 years (mean 4.5 years). The original graft (Dacron-17, polytetrafluoroethylene-3) was an aortobifemoral in 14, axillofemoral femorofemoral in 3, iliofemoral in 2, and femoropopliteal in 1 patient. Presenting symptoms were groin false aneurysm with perigraft fluid in 10, inflammatory mass in 6, and sinus tract in 4. At surgery all unincorporated graft material and the perigraft capsule were excised from a point where the proximal graft was incorporated, including debridement of vessels at the distal anastomosis. Of the 14 aortobifemoral grafts, only the femoral limbs were excised at the initial presentation of biofilm infection. The conduit was replaced with an in situ polytetrafluoroethylene interposition graft, which was covered with a gracilis or sartorius muscle flap when possible.
Results: All surgical sites healed, all grafts remained patent, and there was no limb loss. After ultrasonic oscillation of the explanted graft, bacterial cultures recovered coagulase-negative Staphylococcus species in 14, coagulase-positive Staphylococcus species in one, both species in three, with no growth from two specimens. During follow-up, two patients have had clinical involvement in the proximal intraabdominal portion of the graft that had not been previously resected. In all grafts, the in situ replacement graft remained well incorporated.
Conclusion: In situ graft replacement is effective treatment for biofilm infections of vascular prostheses. Because of the indolent nature of these infections, subsequent infection of previously uninvolved graft segments may be expected.