Bacteriologic monitoring in abdominal aortic surgery

In patients who undergo abdominal aortic operations, cultures have been recommended perioperatively to identify potential sources of graft infection. Bacteriologic monitoring was done in a group of patients receiving antibiotics prophylactically. Of 197 bowel bag cultures, 28 (14.2%) demonsrated small numbers of bacteria, usually Staphylococcus epidermidis, while of 31 aneurysm wall cultures, 7 (22.6%) grew bacteria. Four (6.6%) of 60 urine cultures done preoperatively indicated a significant bacteriuria, necessitating postponement of elective operations. Twenty-eight (46%) of 61 wounds revealed organisms of low pathogenicity, none of which caused overt infection. While the majority of 63 nasal cultures grew bacteria, this result did not influence the management of any patient. Eleven graft infections occurred in 517 abdominal aortic grafts inserted between 1967 and 1977. In three patients, infection was already present at the time of emergency operation while in another three, infections occurred subsequently, due to paraprosthetic-enteric fistulas in two and septicemia secondary to an operation on the genitourinary tract in the third. In the remaining five patients, no cause for infection was identified. Thus, no bowel bag culture and only one aneurysm wall culture was useful. This study has failed to demonstrate the value of routine cultures perioperatively in patients who undergo abdominal aortic operations.