Operative closure of isolated defects of the ventricular septum: planned delay.

Selection of patients and the timing of operation for closure of ventricular septal defect (VSD) can be difficult because the risk of operation must be balanced against the hemodynamic abnormality and the age and size of the infant. In the past 6 years we have individualized our approach to the timing and necessity of operation in the patient with an isolated VSD. During this period, 133 patients with VSD were evaluated, and 71 underwent operative closure of the VSD. Of the 133 patients, 90 were 2 years old or younger, and 40 of them required operation because of congestive failure and growth retardation. Of the 45 infants who did not undergo operation, 17 have small intracardiac shunts with normal pulmonary vascular resistance while the other 28 infants remain compensated and are growing despite moderate left-to-right shunts. A persistent, large intracardiac shunt was the indication for operation in 31 of the 48 older patients; the other 17 older patients remain well. Although 3 severely growth-retarded infants (2 to 4 kg) died soon after operation, all infants weighing 4 kg or more survive. No child has died during preoperative observation, and irreversible pulmonary vascular changes have not occurred. Most infants with VSD and large intracardiac shunts do require early VSD closure, but the risk of operation remains high in the tiny neonate with profound failure. With appropriate hemodynamic and clinical criteria, operation for selected infants can be delayed so that the risk of operation can be minimized.

Hemoptysis and pulmonary aspergilloma: operative versus nonoperative treatment.

The clinical experience with 42 patients with pulmonary aspergilloma evaluated at the Vanderbilt University Affliated Hospitals in a 22-year period was reviewed to determine the necessity and advisability of pulmonary resection. Twenty-nine patients (69%) had sustained one or more episodes of gross hemoptysis. Eleven of the 42 patients were treated operatively with lobectomy, wedge resection, or cavernostomy. Five of them had had hemoptysis preoperatively, but in only 1 patient was massive hemoptysis the primary indication for operation. The single death among these 11 patients occurred in the patient undergoing operation for control of massive hemoptysis. Nonoperative treatment was selected in 31 patients because of advanced chronic lung disease. Twenty-four of these 31 patients experienced 41 episodes of gross hemoptysis during observation periods up to 8 years (average, 32 months). Superimposed bacterial infection usually accompanied the episodes of hemoptysis, and medical therapy with bedrest, antibiotics, and postural drainage was successful in controlling the hemorrhage in 40 of the 41 episodes. One patient died from massive hemoptysis. On the basis of this experience, pulmonary resection for aspergilloma in patients with hemoptysis seems rarely indicated.

Ischemic cardiomyopathy: medical versus surgical treatment.

The natural history of patients with ischemic heart disease and depressed left ventricular function is dismal, and medical therapy has failed to alter its course. To assess the results of aorta-coronary bypass grafting in patients with coronary artery disease and decreased left ventricular ejection fraction (LVEF less than or equal to 0.3), we compared 70 medically treated patients to 46 patients having aorta-coronary bypass grafting. The duration of follow-up was 6 to 72 months (mean 19 months). All patients had angina pectoris. Congestive heart failure was present in 56 percent (39/70) of the medical and 43 percent (20/46) of the surgical group. The medical group had a mean LVEF of 0.20 and a mean left ventricular end-diastolic pressure (LVEDP) of 29 mm. Hg. The surgical group had a mean LVEF of 0.21 and a mean LVEDP of 24 mm. Hg. Three vessel disease was found in 60 percent (42/70) of the medical group and 83 percent (38/46) of the surgical group. The operative mortality rate in the surgical group was 4 percent (2/46). There were four late deaths. The 2 year actuarial survival rate for medical and surgical groups was 47 percent and 83 percent, respectively. Significant improvement in angina pectoris and/or congestive heart failure was found in 16 percent (11/70) of medically treated patients and 95 percent (38/40) of the surgically treated patients. Aorta-coronary bypass grafting can be performed in patients with poor left ventricular function with a low operative mortality rate, relief of angina pectoris, and improvement in symptoms of congestive heart failure.

Contemporary management of myasthenia gravis: the clinical role of thymectomy.

Thirty-six patients with myasthenia gravis have been evaluated and treated over the past five years. Eleven patients had ocular myasthenia gravis and responded well to anticholinesterase medications. Twenty-five patients had generalized myasthenia gravis, and 22 of them were initially treated with anticholinesterase medications; 18(82%) failed to improve or to maintain an initial improvement on medication, and 14 of these 18 patients underwent thymectomy. In addition, 3 patients underwent thymectomy as part of their initial treatment during the later part of this study. All thymectomies were performed through a median sternotomy. All 17 patients manifested sustained improvement as judged by a gain in strength and decrease in medications. Thymectomy is beneficial in the treatment of myasthenia gravis, and it is most efficacious when performed early in the course of the disease.

Lung water and urea indicator dilution studies in cardiac surgery patients. Comparisons of measurements in aortocoronary bypass and mitral valve replacement.

We measured transpulmonary indicator dilution curves of 51Cr-erythrocytes, 125I-albumin, 14C-urea, and 3H-water before and six and 24 hours after operation in seven patients undergoing aortocoronary bypass (ACB) and eight patients undergoing mitral valve replacement (MVR). We calculated cardiac output (CO), extravascular lung water (EVLW), the difference between 125I-albumin and 51Cr-erythrocyte distribution volumes (EV albumin), the difference between 14C-urea and 51Cr-erythrocyte distribution volumes (EV urea) and 14C-urea extraction (E) and permeability -surface ares (PS) products. Comparisons between 16 ACB studies and 17 MVR studies showed the MVR group to have a higher EVLW (P less than 0.01). Extravascular lung water decreased after operation. The ratio of EV urea to EV albumin averaged 1.35 in the MVR group and 0.91 in the ACB group (P less than 0.001). 14C-urea E was also higher in the MVR group (P less than 0.05), but PS was similar in the two groups. None of the differences was related to the time that studies were done. We showed that EVLW, calculated using both 125I-albumin and 51Cr-erythrocytes as intravascular indicators and measured blood water content, had a constant relationship to EVLW calculated using only 125-I-albumin as the intravascular indicator and neglecting blood water content, over a broad range of cardiac outputs, hematocrist, and lung water volumes. We conclude that patients with mitral valve disease have an increased distribution volume and E for urea, probably due to hemodynamic changes but possibly due to increased vascular permeability. Extravascular lung water decreases after cardiac surgery regardless of the type of operation. A single intravascular indicator is adequate for estimating extravascular lung water in humans.

Effect of blood flow rate on subendothelial proliferation in venous autografts used as arterial substitutes.

The effect of augmented and reduced blood flow rates through autogenous vein grafts (AVG) on the histological characteristics of veins used for arterial substitutes was studied in 22 dogs. In each animal autogenous jugular veins were implanted as conduits to replace excised segments of both iliac arteries. In one group (control) blood flow through the AVG conduits was not modified, but in the remaining animals blood flow rate was either augmented by a distal femoral arteriovenous fistula or reduced by a distal arterial stenosis. In the control group in which there was no modification of blood flow, subendothelial proliferative lesions (SEPL) were found in the vein graft, and typical SEPL were found at each anastomosis. However, in those animals in which blood flow was reduced by an average of 44% through the graft, SEPL were more numerous throughout the length of the vein graft, and the anastomotic SEPL were more prominent. In contrast, those animals in which a unilateral distal arteriovenous fistula augmented blood flow through the AVG (average 6.7-fold increase), no SEPL were detected along the length of the graft. Although SEPL were present at the suture lines, the lesions were much less prominent. These findings suggest that the magnitude and distribution of SEPL in AVG are determined, in part, by the rate of blood flow through the graft.

Unstable coronary artery disease: comparison of medical and surgical treatment.

In eighty-eight patients with arteriographic findings of obstructive coronary artery disease and the clinical picture of unstable angina pectoris, a decision on operative or nonoperative management was made by the attending physician. Fifty-three of them subsequently underwent aortocoronary saphenous vein bypass grafting and 35 were continued on a program of medical therapy. A marked difference in the course after the first 30 days was noted, with most of the surgically managed patients being either asymptomatic or greatly improved following coronary artery bypass. Two-thirds of the medically treated patients had persistent severe angina pectoris and non was asymptomatic in a follow-up period averaging 20 months. There were 2 late deaths in the medical group and none in the surgical group. These findings indicate that coronary artery bypass operations can be performed with low risk during the unstable phase of coronary artery disease and that relief of angina can be anticipated. In contrast, nonoperative management of unstable coronary artery disease carries an appreciable risk of death or myocardial infarction, and the majority of patients treated nonoperatively continue to experience angina.

Depression of human myocardial contractility with "respiratory" and "metabolic" acidosis.

The effect of a similar degree of "respiratory" and "metabolic" acidosis was studied in seven isolated in vitro human pectinate muscles and eight ventricular muscle bundles. Either "respiratory" or "metabolic" acidosis (from 7.36 plus or minus 0.03 to 7.01 plus or minus 0.02 and 6.98 plus or minus 0.03, respectively) depressed in vitro contractility in human atrial or ventricular muscle to a similar extent. Previous contradictory responses of myocardial tissue to alterations in pH appear to be the result of species differences.