Faculty Bibliography

Although retrograde cardioplegia has been shown to provide adequate overall protection to the myocardium, delivery of cardioplegic solution to the right ventricle and septum is poor. We used an animal model of occlusion of the left anterior descending coronary artery to study the effects of modifying the conditions of retrograde cardioplegia administration on delivery to the right and left ventricles. Adult mongrel dogs (n = 12) were each given five retrograde injections of microsphere-labeled cardioplegic solution at 10-minute intervals. Four injections were made directly into the coronary sinus with ostial balloon occlusion at the following dosages and pressures: (1) 10 ml/kg at 30 mm Hg, (2) 20 ml/kg at 30 mm Hg, (3) 10 ml/kg at 50 mmHg, and (4) 20 ml/kg at 50 mm Hg. A fifth dose (20 ml/kg) was given directly into the right atrium at 50 mm Hg. Delivery of cardioplegic solution to the left and right ventricles was significantly reduced when the right atrial route was compared with the coronary sinus route at the same dosage and pressure (for left ventricle, 6.0% +/- 1.4% versus 22.7% +/- 11.4%/100 gm, p less than 0.001; for right ventricle, 0.7% +/- 0.2% versus 4.1% +/- 0.4%/100 gm, p less than 0.001). Septal delivery was less than that to the anterior and posterior left ventricle (10.4% +/- 1.3% versus 30.3% +/- 3.9% and 27.9% +/- 3.1%/100 gm, p less than 0.0001) for all injections. Delivery to the body of the right ventricle was less than that to the inflow and outflow tracts (1.8% +/- 0.2% versus 4.5% +/- 0.7% and 8.4% +/- 1.5%/100 gm, p less than 0.0001). These results indicate that, in this model, (1) the right atrial route provides less overall cardioplegic solution to both ventricles than direct retrograde coronary sinus cardioplegia and (2) regional abnormalities in distribution with direct retrograde coronary sinus cardioplegia are not affected by changes in the dosage or pressure of injection

Previous studies have provided conflicting evidence as to whether an increased risk of mediastinitis is associated with use of the internal mammary artery as a coronary bypass graft. In this study the effects of internal mammary artery grafts on wound complications were analyzed in a prospective, nonrandomized fashion. At New York University Medical Center from January 1985 through May 1988, 2356 patients underwent isolated coronary revascularization. Among these patients 1394 received one or more internal mammary artery grafts (group I) and 962 had vein grafts only (group II). Group I had a mean age of 59.5 years versus 67.7 years in group II; diabetes was equally present in both groups (22.7% versus 24.7%). Operative mortality rate was 1.3% in group I and 5.6% in group II. Sternal infection was significantly more prevalent in group I (2.2%, 31/1394) than in group II (0.8%, 8/962). Multivariate analysis revealed that aortic crossclamp time, use of a single internal mammary artery graft, use of a double mammary graft, and diabetes were associated with increased risk of sternal infection. The use of bilateral internal mammary artery grafting doubled the odds ratio of the risk compared with use of a single mammary graft, and the combination of diabetes and double internal mammary artery grafts increased the odds ratio 13.9-fold. Patients with an internal mammary artery graft who had sternal infection had a longer period of hospitalization than patients without a mammary artery graft who had sternal infection. We conclude that the risk of sternal infection is increased by the use of an internal mammary artery graft, especially use of double mammary grafts in the presence of diabetes

Seventy-one patients aged greater than or equal to 80 years (mean +/- standard deviation 82 +/- 2) with aortic stenosis or mixed stenosis and regurgitation underwent aortic valve replacement alone (n = 35, group 1) or in combination with a coronary artery bypass procedure without any other valve procedure (n = 36, group 2). Preoperatively, 91% had severe cardiac limitations (New York Heart Association class III or IV). Hospital mortality was 12.7% overall (9 of 71), 5.7% (2 of 35) for group 1 and 19.4% (7 of 36) for group 2. Perioperatively, 1 patient (1.4%) had a stroke. Survival from late cardiac death at 1 and 3 years was 98.2 and 95.5%, respectively, for all patients, 100% for patients who underwent isolated aortic valve replacement, and 96.3 and 91.2%, respectively, for patients who underwent aortic valve replacement plus coronary artery bypass. Eighty-three percent of surviving patients had marked symptomatic improvement. Freedom from all valve-related complications (thromboembolism, anticoagulant, endocarditis, reoperation or prosthetic failure) was 93.3 and 80.4% at 1 and 3 years, respectively. Thus, short- and long-term morbidity and mortality after aortic valve replacement for aortic stenosis in patients aged greater than or equal to 80 years are encouragingly low, although the addition of coronary artery bypass grafting increases short- and long-term mortality

Left ventricular aneurysms and diverticula are rarely encountered in the pediatric age group. This paper reports a case of congestive heart failure and mitral regurgitation in a 6-year-old boy with a large posterolateral left ventricular aneurysm. Complete repair was successfully performed by excision of the aneurysm and Dacron patch reconstruction of the left ventricular free wall. The patch extended onto the posterior annulus of the mitral valve, thus restoring the mitral valve to normal geometry and correcting the mitral insufficiency. The surgical literature on congenital cardiac diverticula and acquired aneurysms in children is reviewed and summarized

A retrospective analysis of an institutional experience with aortic valve replacement (AVR) in patients 70 years of age or older during 1976 to 1987 was performed. The study was prompted in part by the current interest in palliative aortic valvoplasty, an interest based to a certain extent on the impression that AVR in the elderly has a high mortality. The mean age of the patients was 75.0 +/- 4.0 years (+/- the standard deviation) (range, 70 to 89 years). Eighty-three percent of patients received porcine valves and 17%, mechanical valves. Preoperatively 32% were in New York Heart Association class III, and 59% were in class IV. Operative mortality was 5.6% for elective isolated AVR for aortic stenosis (19% of all patients), 8.2% for all isolated AVR (38%), and 12.4% overall. Concomitant operative procedures were done in 62.0%; AVR with coronary artery bypass grafting (42%) had an operative mortality of 14.3%. Multivariate analysis showed significant predictors of operative mortality to be emergency operation (p less than 0.01), isolated aortic regurgitation (p = 0.01), and previous cardiac operation (p = 0.02). Follow-up (34 +/- 27 months) was 94% complete. Five-year survival from late cardiac-related death was 81.0%. The constant yearly hazard rate for late death for patients 70 years of age or older who underwent AVR was 5.42% per year, which is similar to the 5.77% per year rate calculated for age-matched and sex-matched controls. Five-year freedom from reoperation was 99%; from late thromboembolic complications, 91%; and from late anticoagulant-related complications, 94%. Freedom from all valve-related morbidity and mortality was 61% at 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Results of surgery in 165 patients with aneurysms of the ascending aorta and aortic arch during 1978-1988 were analyzed retrospectively. Etiology included 29% dissection, 22% atherosclerosis, 22% cystic-medial necrosis, and 27% other causes. Concomitant procedures on the aortic valve were performed in 65% of patients (valvular replacement in 37%, valve-conduit in 23%, and valvular resuspension in 5%), and 13% underwent concomitant coronary artery bypass surgery. Major changes in our operative technique for such aneurysms have been introduced during the last 5 years, especially use of a continuous suture-graft-inclusion technique in 99% of patients, use of circulatory arrest in 59%, and use of an open hemiarch repair in 32%. Hospital mortality dropped from 17.9% during the first 5 years of the study period to 12.3% in the last 5 years despite increasing complexity of the cases encountered. Operative mortality was 7.6% for ascending aortic aneurysmal repair; 5.3% for valve-conduit procedure; 8.8% for open hemiarch repair; and 30.8% for repair of extensive aneurysms involving the aortic arch and significant portions of the descending aorta. Multivariate analysis showed that, of the variables examined, significant predictors of increased operative risk were age (p less than 0.05) and extension of an ascending aortic aneurysm to the descending aorta or involvement of the aortic arch (p less than 0.001). The incidence of stroke was 2.4%, with only one stroke since 1983 despite more extensive use of circulatory arrest since that time. Follow-up was 94% complete, with a mean (+/- SD) follow-up interval of 28 +/- 24 months.(ABSTRACT TRUNCATED AT 250 WORDS)

The time to begin ventilating a cardiac surgical patient recovering from hyperkalemic arrest is controversial. Those who advocate ventilating as soon as the left ventricle begins to eject believe that blood ejected from the left ventricle is likely to be hypoxic since it perfuses collapsed, nonventilated alveoli and that this may be the major blood supply perfusing the coronary arteries. The present study attempts to answer this question by sampling blood gases from the aorta in proximity to the coronary ostia in patients both before and after ventilation. Ten patients undergoing coronary artery bypass grafting using the left internal mammary artery were studied. Each patient served as his own control. Distal anastomoses were placed under hyperkalemic, hypothermic cardiac arrest. The aorta was unclamped, and an intrinsic or paced heart rate of 70 beats per minute was achieved. The heart was allowed to eject to a pulse pressure of 20 to 40 mmHg. Rectal temperatures were between 32 degrees C and 34 degrees C. Blood gases were drawn simultaneously from the proximal aortic root, radial artery, pulmonary artery, and the venous circuit of the cardiopulmonary bypass (CPB) machine. The lungs were then twice inflated with a sustained positive pressure of 30 cm H2O, and the patient was ventilated (10 mL/kg tidal volume, FIO2 1.0, 10 breaths per minute) for two minutes. Another set of blood gases was then obtained. Filling pressures, aortic systolic and diastolic pressures, and CPB flows were kept constant for both sets of samples. There was no significant difference in aortic root PaO2 attributable to ventilation. PCO2 was significantly lower, and pH was significantly higher in the ventilated group.(ABSTRACT TRUNCATED AT 250 WORDS)