Outcome of aggressive surveillance colonoscopy in ruptured abdominal aortic aneurysm.

PURPOSE

Emergent repair of ruptured abdominal aortic aneurysms (rAAAs) is associated with high perioperative morbidity and mortality. One of the significant complications of this surgery is bowel ischemia. Reports detail mortality as high as 80% when this condition is realized. The objective of this project was to determine both the incidence and the effect of mandatory postoperative colonoscopy on outcome of colon ischemia after rAAA.

METHODS

From July 1995 to September 2002 all patients with an rAAA who underwent emergent aortic reconstruction were included in this review. All colonoscopies were performed within 48 hours, ischemia was graded consistently, and treatment was initiated per protocol based on grade of ischemia. Patients with grades I and II ischemia were followed up with medical management and repeat colonoscopy. All patients with grade III ischemia underwent bowel resection. Preoperative, intraoperative, and postoperative variables were collected to assess possible independent risk factors for and predictors of bowel ischemia.

RESULTS

Eighty-eight patients underwent emergent aortic reconstruction because of rAAA in the study period. Their mean age was 73 years, and 64 patients (72%) were men. Operative mortality was 42%. Eighteen percent of patients died within 24 hours, and 24% died between 1 and 30 days after surgery. Colonoscopy was performed in 62 of 72 patients who survived more than 24 hours. Bowel ischemia was documented in 26 of the 72 patients (36%). Of these, 16 patients had grade I or grade II ischemia at both initial and repeat endoscopy. Nine patients underwent exploratory laparotomy with bowel resection because of grade III ischemia; two procedures were performed because of worsening ischemia discovered at repeat colonoscopy. In patients with colonoscopic findings of bowel ischemia the mortality rate was 50% (13 of 26 patients). In those with grade III necrosis who underwent resection the mortality rate was 55%. Elevated lactate levels, immature white blood cells, and increased fluid sequestration were all variables associated with the occurrence of colon ischemia.

CONCLUSIONS

Bowel ischemia is a frequent postoperative complication (42%) of repaired rAAA. Performing mandatory surveillance colonoscopy in these patients may be associated with a decrease in overall mortality and improved survival in patients with transmural bowel necrosis with no comorbid condition.