Search PubMed⌕ Search

Biomedical subjects

C N Barnard

Publications and source records attributed to C N Barnard.

At least 37 records · Page 2Linked to original sources

The surgical treatment of tetralogy of Fallot.

This is a review of the last 307 patients with tetralogy of Fallot who were operated on in our unit at Groote Schuur Hospital and Red Cross War Memorial Children's Hospital. Complete repair was undertaken in 301 patients, and shunts were performed in 6 children. There were 17 hospital deaths and 1 late death. The mortality was 5.5% for children less than 12 years old and 6.6% in patients between 12 and 20 years old. During this study period, there was a change in our policy as to when complete repair should be attempted. At present, we perform systemic-pulmonary shunts in patients less than 6 months old and delay complete repair until the child is 2 years old. In deciding whether a shunt should precede complete repair, our experience has shown that age is not as important a consideration as the anatomy of the outflow tract of the right ventricle and pulmonary arteries.

Adolescent↗

Coarctation of the aorta in infants under 1 year of age.

Untreated coarctation of the aorta in infants is associated with a high mortality, reaching up to 90%. During a period of 7 years 26 infants underwent surgical repair of this condition, the youngest being 6 days old and the oldest 11 months. Two underwent emergency surgery after catheterization, while the rest had an elective or semi-elective operation. Associated anomalies were present in 85% of the whole group; of the 22 patients with anomalies, a ventricular septal defect (VSD) and patent ductus arteriosus (PDA) were present in 11 patients, a PDA in 7, a VSD in 6, transposition of the great arteries in 3, an atrial septal defect in 3, a single ventricle in 1, a hypoplastic aortic arch in 1, a hypoplastic left ventricle in 1 and a partial anomalous pulmonary venous defect in 1. Four patients (15%) had no other associated anomaly. The surgical techniques used were coarctectomy and end-to-end anastomosis in 61,5%, subclavian flap aortoplasty in 27%, and Dacron patch aortoplasty in 11,5%. Additional pulmonary artery banding was performed in 6 patients; in 2 patients lung biopsies were also carried out in order to establish the severity of pulmonary hypertension. The overall hospital mortality was 30,7%. No patients with uncomplicated coarctation died.

Aortic Coarctation↗

Malignant neoplasms occurring after cardiac transplantation.

Fifty-seven cardiac transplants in 53 patients have been performed; 30 survived for at least three months. Malignant neoplasms developed in three (10%) of these patients. This incidence is more than double that in recipients of donor kidneys at our institution. Kaposi's sarcoma developed in three patients in the combined groups and accounted for 30% of all malignant neoplasms. The possible reasons for these high incidences are discussed.

Adenocarcinoma↗

Trends in cardiac surgery at the University of Cape Town, 1971-1981.

A review has been undertaken of the number and types of surgical procedures performed in the Department of Cardiac Surgery of the University of Cape Town during the 11-year period 1971-1981, together with data on associated mortality. A yearly average of 560 operations was carried out, of which 75% were for acquired and 25% for congenital heart disease. The number of patients treated continues to rise, from 434 in 1971 to 690 in 1981. There has been a slight reduction in the overall average yearly mortality, from 6.1% between 1971 and 1975 to 5.0% between 1976 and 1981. There was a significant increase in the number of valve replacements in 1975 and 1976 and a more recent, continuing increase in operations for ischaemic heart disease, which now form 19% of the total operations. In both these groups the average yearly mortality has fallen during the period of study. The number of operations each year for congenital heart disease has remained fairly constant, but, disappointingly, there has been no significant reduction in mortality.

Adolescent↗

Analysis of surgical versus medical therapy in active complicated native valve infective endocarditis.

From 1972 to 1980, 23 patients (Group A) with native valve infective endocarditis underwent surgical intervention, often for multiple indications, during the active stage of the infective process because of progressive class III and IV (New York Heart Association) heart failure (12 patients), persistent severe hypotension (3 patients), uncontrolled infection for over 21 days (11 patients), aortic root abscess (2 patients), and pericarditis (1 patient). Eighty-five patients (Group B) with active native valve endocarditis, matched for severity of illness, were treated medically. Two patients (9%) in Group A and 43 patients (51%) in Group B died during the hospital admission (p less than 0.001). Any difference in long-term cumulative survival rate between the 2 groups was largely due to the beneficial impact of surgical management on the hospital mortality. Of 23 patients in Group A, 11 (48%) had an entirely uncomplicated postoperative course. Long-term mortality rates in those with aortic valve endocarditis treated medically (79%) were significantly higher than in those with mitral valve involvement (47%) (p less than 0.05). Patients with aortic valve involvement treated surgically had a better hospital (p less than 0.005) and long-term (p less than 0.0005) survival rate than those treated medically. Two groups at risk for postoperative complications were identified; 3 of 11 patients (27%) with uncontrolled infection had an early postoperative recurrence, and 4 of 7 patients (57%) with an aortic root abscess had postoperative prosthetic paravalvular regurgitation. Surgery therefore effects a substantial reduction in hospital mortality in patients with complicated active infective endocarditis (9% versus 51%), but patients with preoperative prolonged periods of uncontrolled infection or with aortic root abscess are liable to postoperative complications.

Adolescent↗

Orthotopic allotransplantation and autotransplantation of the baboon heart following 24-hr storage by a portable hypothermic perfusion system.

A nonpulsatile perfusion apparatus, based on the air-lift pump principle, has been developed. Circulation of the perfusate, as well as oxygenation and maintenance of acid-base balance, is provided by the flow of a mixture of 97% oxygen and 3% carbon dioxide. The system is easily and entirely portable. Eleven baboons underwent orthotopic allotransplantation with donor hearts stored by continuous hypothermic (4-10 degrees C) perfusion for periods of up to 24 hr. Three were electively killed after 2 to 3 days; the remaining eight, immunosuppressed with methylprednisolone and either azathioprine or cyclosporin A, survived to rejection at between 10 and 49 days. Cardiac catheterization performed in six animals 7-14 days after allotransplantation showed virtually normal hemodynamic data. Three more baboons underwent heart excision and storage by hypothermic perfusion for 24 hr, and subsequent othotopic autotransplantation, the circulation of the baboon being maintained in the interim by an allograft. One animal survives 8 months later with hemodynamic data at cardiac catheterization differing little from that obtained before autotransplantation. This perfusion system has subsequently been used to store four human donor hearts prior to heterotopic transplantation.

Animals↗

The surgical technique of heterotopic heart transplantation.

The surgical technique of heterotopic heart transplantation is detailed and illustrated. The donor heart is excised after cardioplegic arrest and topical cooling; its preparation and implantation in the recipient are described. Emphasis is placed on ensuring nonrestrictive anastomoses between the left and right atria of the recipient and the donor, on estimating the optimal length of the donor aorta, and on the insertion of a prosthetic graft between the donor and the recipient pulmonary arteries. Forty-six such transplants have been performed to date without operative or early postoperative mortality related to technical problems.

Heart Atria↗

Infectious complications after heart transplantation.

Infection has been the major cause of death and morbidity in patients undergoing cardiac transplantation at Groote Schuur Hospital. Twenty-two (55%) patients suffered at least one major episode of infection, which accounted for 10 (59%) of the deaths in the first year. The major site of origin of infection was the lung, though dissemination was not infrequent. Bacteria accounted for 22 (59%) infections; but viral, fungal and protozoal infections were not uncommon and in fact accounted for seven (64%) of the fatal infections. Several unusual causative microorganisms have been isolated in this group of immunocompromised subjects. There is a higher incidence of infection in patients over the age of 35 years and in patients who did not comply with instructions and advice.

Adult↗

Toxoplasmosis of donor and recipient hearts after heterotopic cardiac transplantation.

Toxoplasmosis of both donor and recipient hearts was diagnosed by means of endomyocardial biopsy specimens after heterotopic cardiac transplantation for dilated cardiomyopathy. Before transplantation, the donor had raised antibody titers to Toxoplasma, and the recipient was negative. When toxoplasmosis was diagnosed on the basis of endomyocardial biopsy specimen, the recipient had a greatly elevated antibody titer of 1:1,027. This suggests that the infection could have been transferred with the donor heart. The mononuclear cell response elicited by disrupted toxoplasmic cysts interferes with the diagnosis of rejection in graft biopsy specimens. Electron microscopy is valuable in confirming a light microscopic diagnosis of toxoplasmosis. Drug therapy eradicated the toxoplasmosis, but the patient died later of tuberculous meningitis.

Diagnosis, Differential↗

Medical, legal and administrative aspects of cadaveric organ donation in the RSA.

A shortage of donors remains the major limiting factor as regards the number of kidney and heart transplants performed in South Africa each year. The medical, legal and administrative aspects of cadaveric organ donation in this country are reviewed. The pathophysiology of brain death and the criteria necessary for a definite diagnosis are described, together with the criteria for the selection of cadaveric organ donors. The statutory requirements pertaining to the removal of human hearts and kidneys for the purposes of transplantation are detailed. The subsequent management of the brain-dead donor up to the time of excision of the required organ is described, and a note regarding the preservation and transportation of the donor organs is added.

Age Factors↗

Tricuspid atresia corrected by the Fontan method.

The Fontan procedure was applied to correct 13 cases of tricuspid atresia, all with concordant arterial connections. Seven of the patients had had a total of ten previous operations to create palliative shunts. There were 3 early deaths, all due to low cardiac output states, but no late deaths. The postoperative management of the survivors was not unduly complicated, except in the 1st patient. Complete heart block developed transiently in 2 patients. The results are classified as good to very good in all 10 survivors. Our experience supports the opinion that the Fontan procedure gives good symptomatic relief in patients with tricuspid atresia. We discuss the possibility of improving long-term left ventricular function by early complete correction.

Adolescent↗

The assessment and selection of patients for heterotopic heart transplantation.

In the 2-year period 1979-1980, 34 patients were assessed at Groote Schuur Hospital as candidates for heterotopic heart transplantation. Ischaemic heart disease was the most common underlying cause (19 patients), with cardiomyopathy (9), rheumatic heart disease (2), failed transplants (3), and endomyocardial fibrosis (1) as the other causes of myocardial disease. Five patients were not accepted into the transplant programme, 2 declined after being accepted, and in 3 the initial decision of acceptance was later reversed. Nine patients died while awaiting suitable donors, the mean survival time from the date of acceptance being only 26 days. Fifteen patients underwent heterotopic heart transplantation, 11 remaining alive at the end of the period of study; 8 had normally functioning donor hearts but 3 had suffered irreversible rejection and awaited a second transplant.

Adolescent↗