Revascularization of the septal artery

The septal artery has been infrequently considered for bypass grafting due to its apparent inaccessibility. Twelve patients have recently been found to have a large single obstructed septal artery that supplied an area of left ventricle great enough to justify revascularization. A review of 100 normal arteriograms showed that 30% (30/100) of the patients had a septal artery of sufficient size to sustain a graft. Early restudy of 8 of the 12 patients who received septal bypasses showed all grafts to be patent and functioning well.

Coronary revascularization in "high" versus "low-risk" patients: The role of myocardial protection

Postoperative mortality, infarction, and need for inotropic support are reportedly increased following myocardial revascularization in "high-risk" patients. We believe these complications result from inadequate protection of the compromised myocardium and should not occur with greater frequency in "high-risk" than "Low-risk" patients if the heart is optimally protected during the entire course of the operative procedure. Results following revascularization in 50 consecutive "low-risk" and 50 consecutive "high-risk" patients were analyzed. One or more of the followin factors were present in the "high-risk" group: ventricular dysfunction--ejection fraction less than 0.4, preinfarction angina, evolving infarction, recent infarction (less than 2 weeks), and refractory ventricular tachyarrhythmia. The following principles were used in all patients to minimize ischemic injury: 1) avoidance of pre-bypass hypo- or hypertension, 2) limitation of ischemic arrest to less than 12 minutes, 3) avoidance of ventricular fibrillation, and 4) prolongation of total bypass as necessary to repay the myocardial oxygen debt. Postoperative inotropic support was required in 10% of "high" and 10% of "low-risk" patients, new postoperative infarction developed in 10% of "high" vs. 10% "low-risk" patients; death occurred in 2% of "high" vs. 4% "low-risk" patients. These results are comparable and indicate that optimum myocardial protection allows safe revascularization in the "high-risk" patient.

Evidence that revascularization by ventricular-internal mammary artery implants increases longevity. Twenty-four year, nine month follow-up

Revascularization of the heart is a means of relieving symptoms of coronary artery disease--such as angina, fatigue, and dyspnea. The question of whether revascularization prolongs the life of the patient has been debated. My colleagues and I have reviewed our years of experience with patients treated by implantation of internal mammary arteries into the ventricles. We have compared our series with other groups of patients treated medically. Our conclusion is that revascularization via internal mammary artery implants does increase longevity.

Valve replacement and myocardial revascularization. Results of combined operation in 59 patients

Fifty-nine patients (mean age 57 years) underwent aortic valve replacement or mitral valve replacement combined with saphenous vein bypass grafting (39 single, 19 double, 1 triple) between May, 1970 and January, 1974. The hospital mortality for aortic valve replacement was 4.7% (2 of 43 patients) and for mitral valve replacement 6.3% (1 of 16 patients). There was a 21% incidence of postoperative myocardial injury in the patients with aortic valve replacement and a 6.2% incidence in the patients with mitral valve replacement. Variations in operative technique and in the methods of intraoperative myocardial preservation (coronary perfusion or profound hypothermic ischemic arrest) did not affect hospital mortality or the incidence of myocardial injury. Prolonged periods of ischemic arrest (greater than 50 minutes) were not used. The late mortality for aortic valve replacement was 16.3% (seven patients) and for mitral valve replacement 25% (four patients). There was symptomatic improvement in the majority of survivors. Operative mortality rates for the combined procedures are comparable to those from our institution for valve replacement alone.

Myocardial revascularization in patients with poor ventricular function

Eighty patients with evidence of impaired ventricular function by ventriculography were reviewed. On the basis of the ejection fraction, these patients were divided into three groups. Those with ejection fractions less than 0.2 were considered in very poor condition, those with ejection fractions of 0.2 to 0.4 were considered in poor condition, and those with ejection fractions with between 0.4 and 0.6 were considered fair. Suitability of vessels for bypassing and the presence or absence of collateral cirulation on the cinearteriograms was also noted for possible influence on result. Operative mortality rate in patients having complete repair, defined as bypassing all major vessels with significant obstruction, was 7 per cent. In 26 patients having incomplete repair, the operative mortality was 30 per cent. However, the late mortality rate was not favorably influenced by complete repair, 75 per cent are in improved or good clinical condition, as compared with 65 per cent in the incomplete repair group. As patients with impairment of ventricular contractility are at high risk, it is believed that they should continue to be evaluated on an individual basis for bypass surgery and not categorically denied treatment.

Selection of the candidate for myocardial revascularization; a profile of high risk based on multivariate analysis

A survey of 60 patients who died from cardiac related causes after vein or artery bypass operations alone (1967 to 1973) was made with respect to 26 clinical, angiographic, and operative variables. These factors were compared with identical characteristics of 1,188 survivors operated upon in 1973. Through discriminant analysis, the various characteristics, isolated or multiple in any combination, have been converted into risk related to operative death. The distinctive features of the mortality group were vastly different from those in the surviving group. Ten patients (16.67 per cent) of the mortality group were in the ninety-ninth percentile of risk, whereas these factors or variables of similar weight produced an equivalent risk of only 0.34 per cent of the survivors; thus, operative death in these circumstances could be predicted with an estimated 98.0 per cent assurance. Each of 6 patients with mortality risks above 0.99999 had (1) marked cardimegaly, (2) uncompensated congestive heart failure (CHF), (3) triple vessel coronary artery disease and/or obstruction of the left main coronary artery, (4) generalized impairment of left ventricular contraction or segmental left ventricular scar, and (5) evelated left ventricular end-diastolic pressure. As a single factor, congestive heart failure (CHF) exerted the most influence on the probability of dying. A new and more desctiptive statistical interpretation of the factors presumed to affect risk is presented.

Limitations and prospects of coronary artery surgery

Coronary atherosclerosis is discussed from the standpoint of natural history and survival. The operative treatment for ischemic heart disease is reviewed beginning with the advent of the venous autograft to the most recent advance, the internal mammary artery graft. Comparative survival between medical and surgical modes of treatment are described as well as factors in the revascularization selection process that directly influence longevity. During the last 6 years, experience in selection and a steady improvement in technical proficiency have brought about a decline in operative mortality and morbidity, thus yielding further improvement in postoperative long-term survival.