Ischemic Colitis Following Ruptured Abdominal Aortic Aneurysm

Abstract

During a six-year period, 47 patients underwent operation for ruptured abdominal aortic aneurysm (rAAA) with a mortality rate of 38% (18/47): of the 39 patients surviving the initial surgery, 9 (23%) developed ischemic colitis. All 9 patients demonstrated hyperdynamic cardiovascular changes consistent with sepsis: decreased systemic vascular resistance (SVR) (mean 852 dynes/sec/cm²) and increased cardiac index (mean 3.8 L/min/m²). This "septic picture" in the postoperative period, before the onset of any gastrointestinal (GI) symptoms (diarrhea with/without blood), led the authors to question bowel viability. Flexible sigmoid colonoscopy identified ischemic colitis in all patients and sigmoid colectomy was performed in 4; 3 of these patients survived. Of the 5 remaining patients managed nonoperatively, 3 survived. When hyperdynamic cardiovascular changes were recognized "early" (< forty-eight hours) and ischemic colitis was diagnosed (5 patients), all patients survived. However, when ischemic colitis was diagnosed "late" (> forty-eight hours) after operation in 4 patients, only 1 (25%) survived.

In patients who suffer an rAAA and demonstrate cardiodynamic signs of sepsis (especially falling SVR) in the immediate postoperative period (< forty-eight hours), immediate bedside sigmoid colonoscopy to rule out ischemic colitis is warranted. Similarly, when patients develop "late" cardiodynamic signs of sepsis during recuperation from rAAA, even before the onset of GI symptoms, sigmoid colonoscopy should be performed. If severe ischemic colitis is documented, aggressive management with frequent colonoscopy and possibly sigmoid resection is indicated, for this may offer the only chance of survival in these catastrophically ill patients.