Nonocclusive mesenteric ischemia after off-pump coronary artery bypass surgery: a word of caution.

We present a series of five cases of off-pump coronary artery bypass surgery complicated with fatal nonocclusive mesenteric ischemia. We review a total of 489 patients aged 65 and older (mean age 74.9 +/- 3.2 years) who underwent off-pump coronary artery bypass surgery. The diagnosis of nonocclusive mesenteric ischemia was confirmed by computed tomography-angiography and/or selective angiography of the superior mesenteric artery, or intraoperatively. Three patients underwent laparotomy with bowel resection. In two cases, resection of bowel was not feasible. Of the possible predisposing factors, we found that four of the patients (two preoperative and two perioperative) had received epinephrine and two had an intra-aortic balloon counter pulsation due to acute myocardial infarction and cardiogenic shock. All patients were over 65 years of age, and all had acute anterior wall myocardial infarction and hemodynamic instability or post-myocardial infarction unstable angina. Nonocclusive mesenteric ischemia is a difficult clinical entity to recognize, has no clear-cut effective management, has a poor prognosis as a result of low cardiac output, and can be aggravated by off-pump coronary artery bypass grafting.