Late coronary bypass graft flow: quantitative assessment by roentgendensitometry.

Quantitative assessment of the flow in 45 saphenous vein aortocoronary bypass grafts in 30 patients was performed by a roentgendensitometric technique. Detalis of the technique are given. Mean graft flow for all grafts measured in the early postoperative period (two weeks) and again in the late postoperative period (six months to 3 years; average, 1.5 years) significantly decreased (72.6 +/- 34.7 to 57.4 +/- 28.6 ml/min; p less than 0.01). Mean graft diameter also significantly decreased over the same period (3.5 +/- 0.6 to 3.0 +/- 0.6 mm; p less than 0.01). Differences could not be related to graft site or to the time interval between early and late recatheterization. Changes in diameter did not correlate with changes in flow. During a 3-year follow-up, saphenous vein grafts significantly decreased in diameter and flow but still functioned adequately; and vein grafts generally remained larger than the recipient arteries. The determinant of adequacy of flow is the native coronary bed.

Results of aortocoronary bypass grafting in patients with subendocardial infarction: late follow-up.

Twenty-eight patients with subendocardial infarction (Group A) were compared with 28 patients with unstable angina (Group B) and 28 with stable angina (Group C) matched for age and sex. The three groups did not differ in prevalence of diabetes, hypertension, old infarction or duration of disease. There were no significant differences in number of diseased vessels, coronary score, abnormal left ventricular wall motion or left ventricular end-diastolic pressure. Angiograms performed 2 weeks postoperatively revealed closure of 3 of 31 grafts (16 patients) in Group A, closure of 3 of 34 grafts (17 patients) in Group B and closure of 6 of 50 grafts (22 patients) in Group C (differences not significant). Postoperative angiograms showed improved wall motion in 37 percent of Group A, 53 percent of Group B and 36 percent of Group C (differences not significant). Postoperative new Q waves appeared in one hospital in Group A and in two patients in Groups B and C. There were no hospital or late deaths. In a mean follow-up period of 29 months, 68 percent of patients in Group A, 61 percent in Group B and 54 percent in Group C were asymptomatic. Thus, bypass grafting was performed with similarly low mortality and morbidity in patients with subendocardial infarction and in those with angina; more than one third of postoperative angiograms in the three groups showed improved wall motion; and late follow-up studies demonstrated functional improvement in the majority of patients in all three groups.

Survival after coronary surgery.

A 4.4 year follow-up study has been done on a previously reported group of 200 consecutive patients who underwnet coronary bypass. The yearly mortality rate has been 1% (8/200 in 4 years). Our total group of 1,038 surgically treated patients has had an operative mortality rate of 1.3%, and an early graft patency rate of 89.6% has been recorded in the 60% of patients consenting to restudy. These results are compared to natural history studies with and without angiography. Comparison with recent prospective randomized studies of patients with chronic stable angina and those with unstable angina suggests that a low operative mortality rate and optimal technical performance are necessary to improve the survival rate of patiens with symptomatic obstructive coronary disease.

Significance of new Q waves after bypass grafting: correlations between graft patency, ventriculogram, and surgical venting technique.

New postoperative electrocardiographic Q waves have been described in eight of 40 per cent of patients undergoing bypass grafting for coronary artery disease. Various theories have been proposed to explain these new Q waves. Correlations of new Q waves to vein bypass occlusion, prolonged pump time or aortic cross-clamping time are controversial. Indeed, whether or not the appearance of new postoperative Q waves means real transmural myocardial infarction is not clear. We report herein our experience with postoperative Q waves in 56 patients with vein bypass grafts and the relationship of new Q waves to ventricular venting, graft patency, and the postoperative ventriculogram. Our observations indicate that: (1) Not all Q waves are due to occlusion of the saphenous bypass grafts (as noted by others). (2) A certain percentage of new Q waves may not reflect true transmural myocardial infarction, especially when all the vein grafts are patent and the postoperative ventriculograms show improvement. (3) Some new Q waves reflect true transmural infarction due to occlusion of grafts or of distal coronary arteries with deteriorated left ventriculograms. (4) The high incidence of new Q waves in patients with ventricular vents is probably due to direct myocardial trauma at the apex of the left ventricle.

Should the pericardium be closed after an open-heart operation?

A controlled clinical study was carried out to decide whether the pericardium should be left open or closed after open-heart operations. One hundred patients had the pericardium closed with interrupted silk, another 100 had the pericardium left open. Complications were alike except for the more frequent occurrence of a pericardial rub in the closed group (14 vs 3 patients), though the incidence of post-pericardiotomy syndrome was equal. There was no late tamponade. Two early reexplorations for bleeding were done in the open group, none in the closed. There were no postoperative deaths. In the patients who consented to postoperative angiography following revascularization procedures, the incidence of graft failure was equal in both groups. The pericardium should be closed after an open-heart operation. Morbidity and mortality are unchanged, and repeat cardiac exploration is safer.