Risks of bilateral internal mammary artery bypass grafting.

Although use of one internal mammary artery (IMA) for coronary artery bypass grafting does not appear to be associated with increased risk, the results with both IMAs are less certain; the potential for a higher incidence of sternal wound infection as a result of devascularization of the sternum is a major concern. During a 42-month interval ending July 1988, 1,566 patients had coronary artery bypass grafting alone or in combination with other procedures: 633 received only vein grafts, 687 had unilateral IMA grafting, and 246 had bilateral IMA grafting. The IMA patients were younger, were more often male, had better cardiac function, and underwent fewer emergent, urgent, or combined procedures than the patients receiving vein grafts (p less than 0.05). Thirty-day mortality was lower among the IMA patients (unilateral IMA group, 2.8%; bilateral IMA group, 3.7%; and vein graft group, 7.9%; p = 0.001). With the exception of sternal wound problems, occurrence rates for postoperative complications among the IMA patients did not differ significantly from or were lower (p less than 0.05) than those among the patients with vein grafts. Sternal infections occurred with greater frequency among the bilateral IMA patients (6.9%) than among the unilateral IMA (1.9%) or vein graft (1.3%) patients (p = 0.001). By univariate analysis, obesity, diabetes, bilateral IMA grafting, and need for prolonged (greater than 48 hours) mechanical ventilation were associated with a significantly higher incidence of sternal infection (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary artery bypass grafting for postinfarction angina pectoris.

The variables that predict increased operative risk and postoperative morbidity among patients who undergo coronary artery bypass grafting (CABG) early after myocardial infarction for persistent or recurrent ischemia are incompletely defined. In a recent 3-year interval (1985-1987), 240 patients underwent CABG within 30 days of a documented myocardial infarction. Thirty-day mortality was 3.3% (eight patients). Twenty variables were examined by univariate and multivariate analysis for their effects on early mortality. Left main coronary artery disease (p = 0.0003), female sex (p = 0.0059), and preoperative left ventricular dysfunction (increased left ventricular wall motion score) (p = 0.0135) were significant independent predictors of increased 30-day mortality. Postoperative inotropic support for low cardiac output was required for 55.6% of patients operated upon within 24 hours of infarction as compared with 11.6% of patients operated upon between 1 and 30 days (p less than 0.01). Significantly more patients undergoing emergent CABG required postoperative intra-aortic balloon pumping and inotropic support than those patients who underwent urgent or elective operation (23.8% vs. 4.6% and 52.4% vs. 10%, respectively) (p less than 0.01). Other studies confirm that preoperative left ventricular dysfunction, presence of cardiogenic shock, or intra-aortic balloon pumping are important predictors of operative risk. Other variables that may be important include advanced age, female sex, left main coronary artery disease, and anterior transmural infarction. The timing and urgency of operation have not been shown to be significant and independent determinants of increased operative risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Carotid endarterectomy based on duplex scanning without preoperative arteriography.

Between July 1985 and September 1987, 25 patients underwent 26 carotid endarterectomies based on an abnormal duplex scan (B-mode ultrasonography and pulsed-Doppler sound spectral analysis) indicative of severe stenosis or ulceration. Arteriography was not performed because of severe unstable angina requiring coronary artery bypass grafting (23 patients) or patient preference (two). Twelve patients were symptomatic, and 13 were asymptomatic but had severe (greater than or equal to 75%) bilateral or unilateral carotid artery stenosis. Operative and pathological analyses confirmed the duplex-scan findings in all 25 cases. All 25 patients survived the operation. One patient had a transient ipsilateral neurological deficit, and one had a permanent contralateral neurological deficit. Five patients died of ventricular arrhythmias within 30 days of operation. Duplex scanning is an accurate method for determining the presence of clinically and hemodynamically significant carotid arterial occlusive disease. Duplex scanning also serves as an alternative method for evaluating patients for whom carotid arteriography may be associated with significant risk.