Reliability of selective surveillance colonoscopy in the early diagnosis of colonic ischemia after successful ruptured abdominal aortic aneurysm repair.

Purpose: To evaluate the reliability of selective surveillance colonoscopy based on 6 specific perioperative risk factors in the early diagnosis of colonic ischemia (CI) after successful ruptured abdominal aortic aneurysm (rAAA) repair.
Patients and Methods: From 1999 to 2005, 62 consecutive patients underwent rAAA repair. In 59 of them, routine aggressive surveillance colonoscopy was offered every 12 hours within the first 48 hours, and CI was graded consistently. Patients with stage I or stage II CI were treated conservatively and were followed up with repeat colonoscopy, whereas patients with stage III CI underwent immediate laparotomy and colectomy. In parallel, 6 specific perioperative risk factors (PRFs) were retrospectively analyzed.
Results: Overall mortality was 33.9%. Nineteen patients (32.2%) developed CI and 12 (63.2%) of them survived. Thirteen (22%) had grade III CI and among these 6 survived. In patients with CI the mortality rate was 36.2%. Patients with less than 3 PRFs had no CI whereas all instances of CI could be diagnosed if colonoscopy was offered selectively in patients with more than 3 PRFs. The positive predictive value of CI increased with the number of PRFs. Patients with 5 or 6 PRFs were about 101 times more likely to develop CI compared with patients with 0 to 4 PRFs (P<.001).
Conclusion: Our study showed that CI is a frequent complication after successful rAAA repair and could reliably be early diagnosed if surveillance colonoscopy was offered selectively in patients with more than three PRFs.