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.

Initial experience with the Heartstring proximal anastomotic system.

OBJECTIVE: Manipulation of the aorta has been shown to be associated with postoperative neurologic events after surgical myocardial revascularization when the aorta is diseased. The Heartstring proximal anastomotic system (Guidant, Indianapolis, Ind) is a device designed to assist in the performance of proximal anastomoses with minimal aortic manipulation. We describe our initial experience with this product. METHODS: Twelve patients with a diseased aorta who underwent off-pump myocardial revascularization and had their proximal anastomoses performed with the Heartstring device were studied for operative and postoperative outcomes and surgical technique. RESULTS: The mean age of the patients was 76 +/- 7 years. The estimated EuroSCORE perioperative mortality was 12% +/- 8%. The median number of distal anastomoses was 3. In all patients, a saphenous vein graft was anastomosed to the aorta using the Heartstring device. In 5 patients, the radial artery was used as a conduit and connected proximally to a left internal thoracic artery as a Y graft, to a saphenous vein graft as a "horseshoe," or on the hood of a saphenous vein graft. The operative and postoperative courses were uneventful. Three seals developed cracks and were not used. One seal developed an unravel in its periphery but was used successfully. CONCLUSIONS: The Heartstring proximal anastomotic system is a device that allows the surgeon to perform standard proximal clampless anastomoses. Elderly patients with a diseased aorta may benefit from this device.

Long-term beneficial effect of coronary artery bypass grafting in patients with COPD.

OBJECTIVE: This study assesses the impact of COPD on the long-term outcome of patients undergoing coronary artery bypass grafting (CABG). METHODS: Between 1991 and 1993, 37 patients (5.68%) undergoing CABG had significant clinical COPD. They were compared to 37 matched control subjects. RESULTS: The patients in the COPD group had worse preoperative pulmonary function. More patients in this group were smokers, had more symptoms of shortness of breath, and had more preoperative arrhythmia. A total of 13 patients died in the COPD group compared with 3 subjects in the control group during 8.6 +/- 2 years (mean +/- SD) of follow-up with arrhythmia being the major cause of death (62%). Actuarial survival at 9 years was 92% for the control group vs 65% for the COPD group (p = 0.005). The rate of readmissions during mid-term follow-up (13.8 +/- 7.2 months) was higher in the COPD group, and more patients in this group described their quality of life as worse than before the operation (37% vs 3%, p < 0.001). At late follow-up, all survivors in the COPD group had an improved quality of life. Cox regression analysis identified older age and lower FEV(1) as independent predictors of late death. Pulmonary function returned to baseline in the control group and improved to above baseline in the patients with COPD. CONCLUSIONS: Patients with significant COPD have a higher risk after CABG compared to patients without COPD. Nevertheless, when assessing the natural history of patients with COPD, it seems those who undergo CABG benefit from the operation.

Preoperative use of enoxaparin is not a risk factor for postoperative bleeding after coronary artery bypass surgery.

BACKGROUND: The purpose of this study was to determine whether the use of low-molecular-weight heparin before coronary artery bypass surgery would be associated with an increase in bleeding and use of blood products after the operation. METHODS: Sixty-four patients (48 men and 16 women) aged 64 +/- 10 years who were undergoing primary coronary artery bypass surgery were prospectively studied. Forty-one patients were treated with either subcutaneous enoxaparin 1 mg/kg twice daily (n = 21; enoxaparin group) or intravenous heparin (n = 20; heparin group). Patients received the last dose of enoxaparin 8.7 +/- 0.75 hours (range, 8-10 hours) before skin incision. Heparin was stopped before transfer to the operating room. An additional 23 consecutive patients who received neither enoxaparin nor heparin served as controls (n = 23). Anti-factor Xa activity, a measure of enoxaparin and heparin activity, was measured at the start of the operation in all patients. RESULTS: There was no perioperative mortality. The length of stay and frequency of postoperative complications were similar between groups. Preoperative anti-factor Xa activity was present only in the enoxaparin group (0.43 +/- 0.25 IU/mL). Chest tube drainage at 24 hours was 553 +/- 160 mL, 532 +/- 140 mL, and 587 +/- 230 mL for the enoxaparin, heparin, and control groups, respectively (P =.48). There was no difference among groups in the amount of blood products transfused. CONCLUSIONS: Enoxaparin administration more than 8 hours before coronary artery bypass surgery is not associated with increased postoperative bleeding or blood product transfusion.