The impact of multiple operations on the importance of arterial wall cultures.

The present study reviewed arterial culture data from 172 patients undergoing major vascular reconstructions between July 1, 1977, and Dec. 31, 1984. Prosthetic graft infection was documented in 0 of 97 cases (0%) with negative arterial cultures but in six of 75 cases (8%) with positive arterial cultures (chi 2 = 5.84; 0.01 less than p less than 0.025). The data were reanalyzed after the patients were subdivided into two groups on the basis of the numbers of operations: group I (132 patients)--a culture obtained at initial vascular reconstruction--and group II (40 patients)--a culture obtained at a subsequent vascular reconstruction. Positive arterial cultures had no predictive value for graft infection among patients in group I (1 of 57 cases vs. 0 of 75 cases; chi 2 = 0.019), whereas the presence of positive arterial cultures was associated with a significant increase in the incidence of graft infection in group II patients (5 of 18 cases vs. 0 of 22 cases; chi 2 = 4.68; 0.025 less than p less than 0.05). For group I patients, we believe that neither routine arterial culture nor long-term antibiotic therapy for patients with positive arterial cultures is indicated. For group II patients we recommend that routine arterial cultures should be obtained; perioperative antibiotics should be continued until definitive arterial culture information is available; and positive arterial cultures should be treated with a short course of high-dose intravenous antibiotics. Thereafter, long-term treatment of positive arterial cultures with oral antibiotics, although not statistically validated, is probably appropriate.