Antibiotic prophylaxis in aortic and peripheral arterial surgery in the presence of infected extremity lesions. Results of a prospective evaluation.

Over a 6-month period 124 patients submitted to aortic or infra-inguinal arterial reconstruction were alternately allocated to receive cloxacillin plus gentamicin (CX/GM) for 48 hours or cefotaxime (CTX) for 24 hours perioperatively. Evaluations during during the first month were performed by a blinded independent observer and patients were followed for between 6 and 20 months. 63 patients received CX/GM and 61 CTX; the groups were matched for sepsis risk factors. Sepsis rates were: groin and abdominal wounds, CX/GM 5.4% (7 of 129), CTX 6.2% (8 of 127); graft, CX/GM 1.5% (1 of 63), CTX 3.3% (2 of 61). The differences were not statistically significant (p greater than 0.05). Virtually all wound infections were superficial (class I) and no late infections have emerged. 56 patients had infected extremity lesions and 68 had no lesion. There was no significant difference in wound or graft sepsis rates between the 2 groups. Positive cultures of groin lymph nodes and/or aortic clot or atheroma did not predispose patients to postoperative sepsis. The organisms cultured from the extremity lesions were not found in infected wounds of abdominal surgery patients. However, species type and antibiotic susceptibility patterns suggest that the same pathogens were present in wound infections as were isolated from the extremity lesions of patients who underwent infra-inguinal surgery. Thus direct, rather than lymphatic, contamination may be the major aetiological factor. Most infecting organisms were susceptible to the antibiotic used.