The relevance of arterial wall microbiology to the treatment of prosthetic graft infections: graft infection vs. arterial infection.

One potential, but poorly studied source for intraoperative contamination of vascular grafts is the native artery to which the prosthetic graft is attached. The purpose of this study was to analyze the relationship between arterial wall microbiology and graft infection. Between July 1, 1981, and March 31, 1982, arterial specimens were cultured from 88 (30%) of 298 patients undergoing clean, elective arterial reconstructive procedures. Control cultures were obtained from adjacent adipose or lymph node tissue. Positive cultures were obtained from 38 of 88 (43%) of the arterial walls cultured but from none of the control cultures (0 of 20) (p less than 0.001). The most common organism cultured was Staphylococcus epidermidis (27 of 38; 71%). Our overall graft infection rate since January 1, 1981, is 0.9% (3 of 335). All three graft infections occurred in patients with positive arterial cultures. Arterial and graft cultures were also obtained from 20 patients treated for 22 graft infections over the past 13 years. Organisms recovered included staphylococcal species (36%), enteric organisms (46%), and mixtures of the two (18%). These patients with culture-positive graft infections were divided retrospectively into two groups: those with positive and those with negative arterial cultures. Positive arterial cultures were associated with suture line disruption in 8 of 14 cases (57%), but there were no arterial disruptions in patients with negative cultures (0 of 8) (p less than 0.01). These data document a significant correlation between positive arterial wall cultures and subsequent prosthetic infection and also suggest that infection involving the arterial wall is a major determinant of the morbidity and mortality associated with the treatment of prosthetic graft sepsis.