PubMed Health⌕ Search

Biomedical subjects

N E Shumway

Publications and source records attributed to N E Shumway.

At least 19 recordsLinked to original sources
PubMed1992

Current approach to hypoplastic left heart syndrome. Palliation, transplantation, or both?

Over the past 3 years, 35 newborn infants have been referred for surgical management of hypoplastic left heart syndrome. Surgical palliation (first-stage Norwood) or cardiac transplantation was offered. Twenty-four families (68%) chose palliation and 11 families (32%) chose cardiac transplantation. Of the 11 infants listed for cardiac transplantation, five underwent transplantation. Because of a lack of donors after an average wait of 25 days (19 to 31), the remaining six infants underwent palliation, with no perioperative deaths. Of the 30 infants undergoing palliation, including crossovers, 20 (67%) survived the first operative stage. Among the last 19 infants undergoing palliation in 1990, the early survival was 84%. Risk factors determined for poor outcome were year of operation (p less than 0.001) and circulatory arrest time greater than 50 minutes (p less than 0.001). Among the 13 infants undergoing palliation with a circulatory arrest time of less than 50 minutes, there were 12 survivors (92%); among 12 having a circulatory arrest time of more than 50 minutes, there were four survivors (33%). At intermediate follow-up, six infants have undergone second-stage procedures (Glenn), with five survivors. There were eight late deaths, four caused by respiratory infections and four caused by cardiac problems, including a thrombosed shunt in one infant. Three of five infants are alive and doing well after cardiac transplantation. Size of aorta, tricuspid regurgitation, and ventricular wall thickness did not prove to be risk factors. Given the existing data, we believe these infants should be managed selectively on the basis of donor availability and family wishes.

Actuarial Analysis↗
PubMed1992

Current trends in lung transplantation. Lobar transplantation and expanded use of single lungs.

Heart-lung transplantation remains the only therapeutic option for patients with combined end-stage cardiopulmonary disease. Because of the scarcity of heart-lung donors, we have been investigating other surgical alternatives for patients with end-stage vascular and parenchymal lung disease. From June 1989 through June 1991, 48 patients underwent pulmonary transplantation. Seventeen of the 48 patients underwent single lung transplantation. Of the 17 patients in the single lung group, eight patients had pulmonary hypertension and nine had parenchymal lung disease. Four of the 17 patients underwent repair of a cardiac defect with single lung transplantation. One-year actuarial survival was 68%. Pulmonary function has been excellent. The forced expiratory volume in 1 second was 79.6 +/- 13.6 (percent predicted), forced expiratory flow 25%-75% was 72.6 +/- 14.5 (percent predicted), and arterial oxygen tension was 82.8 +/- 10.06 mm Hg when measured at annual follow-up in a group of eight patients without obliterative bronchiolitis. Pulmonary artery pressures of systemic level or greater in the group with pulmonary vascular disease were normal at annual catheterization. Most patients had at least one episode of allograft rejection. Actuarial freedom from rejection at the end of 3 months was 30%. Three of the 17 single lung patients receiving lung lobes were children. Two children received living-related lobe transplants and one neonate received a lobe from a 2-year-old cadaver donor. Single lung transplantation is an effective therapeutic option for selected patients with vascular or parenchymal lung disease. Expanding indications will permit more individuals to receive transplants from the existing donor pool. Living-related and cadaver lobe transplantation will also increase the options available to children in need of lung transplantation.

Adolescent↗
PubMed1992

Cystic fibrosis. Target population for lung transplantation in North America in the 1990s.

Cystic fibrosis is the most common lethal genetic disease occurring in the white population. It is estimated that 3.5% of the 20,000 individuals with cystic fibrosis in North America will die each year of end-stage lung disease. Lung transplantation (heart-lung or double lung) is becoming more frequent as more patients are referred for this procedure. Since January 1988, we have evaluated 60 patients with cystic fibrosis for lung transplantation and have accepted 30 (50%). Nine patients (30%) died while awaiting a donor. Fifteen patients underwent transplantation (13 heart-lung and two double lung procedures). Actuarial survival at 1, 2, and 3 years is 76%. All survivors are without physical limitations. Pulmonary function, as determined by forced vital capacity, forced expiratory volume in 1 second, and arterial blood gas determinations, is within the normal range. Comparing these data with those of a group of patients without cystic fibrosis who underwent transplantation during the same period did not reveal any significant differences with respect to infection, rejection, and outcome. Preliminary data suggest that obliterative bronchiolitis is less prevalent at 1 year in patients with cystic fibrosis (19%) than in those without cystic fibrosis (41%). Patients with cystic fibrosis present a number of challenges. The problems of pleural adhesions from repeated infections, pleurodesis, and previous thoracic procedures are now readily approached through the bilateral thoracosternotomy (clam shell) incision. Insulin-dependent diabetes mellitus and low-dose corticosteroid therapy are no longer considered absolute contraindications. Both septic lungs must be removed at operation, either with heart-lung transplantation or with double lung transplantation. These data support the therapeutic efficacy of lung transplantation for patients with cystic fibrosis.

Actuarial Analysis↗
PubMed1979

Cardiac transplantation in 150 patients at Stanford University.

A total of 150 patients underwent cardiac transplantation at Stanford between January 1968 and August 1978. Sixty-two patients were alive at the end of this period, when the expected one-year survival rate was 70%, with an attrition rate of roughly 5% thereafter. Changes in postoperative managment resulting from continuing research contributed to improved survival rates. The results are equal or superior to those for recipients of renal transplants from unrelated donors. Major centres that have suitably trained staff and appropriate facilities for cardiac surgery should perhaps reconsider cardiac transplantation as an alternative to death in certain patients.

Adolescent↗
PubMed1979

Aortic and mitral prosthetic valve reoperations: early and late results.

A total of 232 valvular reoperations (123 mitral valve reoperations [RMVR] and 109 aortic valve reoperations [RAVR] were performed in 194 patients with previously implanted prosthetic valves. Early mortality was 10% (12/123) for the RMVR subgroup and 14% (15/109) for the RAVR subgroup (P = NS). Late mortality was 16% (18/111) for the RMVR subgroup and 25% (23/94) for the RAVR subgroup (P = NS). Patients with prosthetic endocarditis or prosthetic stenosis constituted higher-risk subpopulations. Principal determinants of both operative mortality and late attrition were preoperative cardiac functional status and the nature of the pathology mandating valve replacement. Early prosthetic valve replacement is advocated to correct hemodynamic abnormalities before advanced ventricular decompensation ensues, especially when prosthetic valvular endocarditis or prosthetic stenosis exists.

Aortic Valve↗
PubMed1979

Two dimensional echocardiographic assessment of patients with bioprosthetic valves.

The clinical utility of two dimensional echocardiography in assessing bioprosthetic and left ventricular function was studied in 40 consecutive patients 1 week to 60 months after valve replacement surgery. These patients were referred to obtain normal baseline studies as well as to evaluate complications:suspected endocarditis, embolic phenomena and congestive heart failure of unknown cause. Independent M mode echocardiograms were also obtained in each patient. Confirmation of ultrasonic studies was by cardiac catheterization with angiography, surgery and pathologic study in 10 patients; cardiac catheterization with angiography alone in 7 patients; surgery and pathologic study in 3 patients; autopsy in 3 patients; blood cultures to confirm or exclude endocarditis in 10 patients; and confirmation on clinical grounds in 7 patients. Technically adequate two dimensional studies were recorded in 39 of 40 subjects. Two dimensional echocardiography accurately assessed 15 of 16 patients with an abnormal bioprosthetic valve and a normal left ventricle (1 of 16 patients had a false positive two dimensional echocardiogram); 8 of 8 patients suspected to have prosthetic valve or left ventricular dysfunction but who were normal; 7 of 7 patients with a normal prosthesis and an abnormal left ventricle; the one patient with an abnormal valve and left ventricle; and 7 of 7 clinically normal patients who were referred for baseline studies. In summary, the two-dimensional echocardiogram demonstrated a 97 percent diagnostic accuracy rate which was significantly greater than the 67 percent (P less than 0.001) for M mode echocardiography in the same group of patients. It is concluded that two dimensional echocardiography has excellent diagnostic accuracy in assessing bioprosthetic and left ventricular function and is superior to M mode echocardiography in evaluating patients after such valve replacement.

Adolescent↗
PubMed1979

Late right heart reconstruction following repair of tetralogy of Fallot.

Twenty-two symptomatic patients underwent a total of 28 reoperative procedures after initial surgical repair of tetralogy of Fallot. Sixteen of the patients were considered to have unfavorable anatomy of the right ventricular outflow tract (RVOT) or pulmonary artery at the time of initial repair. Pulmonary or tricuspid valve replacement, or replacement of both valves, utilizing a xenograft bioprosthesis was performed in 1 of the 22 initial repairs, 7 of the 22 first reoperations, and 5 of the 6 second reoperations. Ultimately, 14 patients received transannular RVOT patches. The interval between the first and second reoperations for 6 patients who required 2 late reconstructive procedures was 5.8 years. No operative deaths occurred. There were 2 late deaths (1 sudden and 1 due to aspiration). Actuarial survival probability (+/- standard error of the mean) 16 years after initial repair was 72 +/- 21%. Eighteen of the 20 current survivors in the present series are completely asymptomatic without physical restrictions; the other 2 are considered to be in New York Heart Association Functional Class II. No xenograft bioprosthetic dysfunction has occurred to date, but cumulative valve follow-up is limited (13 patient-years). In selected patients, earlier pulmonary or tricuspid valve replacement or replacement of both of these valves can provide some degree of protection against recurrent deterioration.

Adolescent↗
PubMed1979

Current management of cardiac transplant recipients.

Changes in the management of cardiac transplant recipients over the past 10 years have resulted in a substantial improvement in the outlook for survival. Imuran and prednisone remain the primary immunosuppressive agents, but rabbit antihuman thymocyte globulin is used initially and reinstituted during rejection. Endomyocardial biopsy has allowed more precise diagnosis and management of rejection, and more recently immunological monitoring has been introduced to provide more frequent assessment of the host immune response. Infection is the major cause of death, and its diagnosis and treatment is managed aggressively. Current survival figures justify the use of cardiac transplantation, by an experienced team, when other measures have been exhausted.

Adolescent↗
PubMed1979

Left ventricular aneurysm. Preoperative risk factors and long-term postoperative results.

The results of operative treatment of postinfarction left ventricular aneurysm in 169 patients undergoing operation since 1970 are analyzed in this report. Maximum follow-up extended to 7 year (average 2.9 years). Average patient age was 56 years (range 34 to 82 years). Nearly all patients (94%) had left anterior descending coronary artery disease with anterior aneurysm formation and 73% had multivessel disease. Sixty-eight percent of patients underwent aorta-coronary bypass grafting (ACBG) and/or mitral valve replacement (MVR) concomitantly with aneurysmectomy. The over-all operative mortality rate was 17.8%. Preoperative factors that correlated significantly (p less than 0.05) with increased operative risk reflected primarily the quality of left ventricular function, and included functional classification, cardiac index, contractile function of residual myocardium not involved by aneurysm, and mitral regurgitation. Patients whose primary preoperative disability consisted of angina pectoris (42 patients) exhibited significantly higher over-all survival rates (actuarial 5 year survival 75%) than those undergoing operation because of congestive heart failure (86 patients) or ventricular tachyarrhythmias (38 patients), whose 5 year survival rates were 52 and 57%, respectively. Concomitant ACBG (+/- MVR) was associated with a higher operative mortality rate than aneurysmectomy alone (21.1 versus 10.9%), but late postoperative attrition was similar. The over-all 5 year survival rate, including operative death, was 60%, and 90% of surviving patients were in Functional Class I or II at follow-up evaluation. We conclude from this analysis that the long-term prognosis of patients with symptomatic postinfection left ventricular aneurysms, although determined importantly by preoperative left ventricular function, is enhanced by surgical treatment.

Adult↗
PubMed1979

Distant heart procurement for transplantation.

Between January 1, 1977, and September 15, 1978, 39 cardiac transplants were performed on 38 patients. Twenty donor hearts were removed at Stanford University Hospital, and 19 donor hearts were removed at distant hospitals. The characteristics of recipients and donors in both groups were similar. The only significant difference between donor hearts was the mean ischemia time (154 +/- 30 minutes in distant hearts and 52 +/- 12 minutes in local hearts, P less than 0.001). As of February 1, 1979, the total mortality rate was 32% for the distant heart donors and 40% for the local heart donors. No difference between the two groups was present in immediate myocardial function, the need for postoperative inotropic support, the mortality rate within the first 90 days after operation, the mean maximum serum enzyme levels, the occurrence of rejection or infection, and the histological appearance of the hearts, both early and late. The results of cardiac transplantation when hearts are removed at distant hospitals are entirely comparable to the results with hearts removed on site with a minimum ishchemic time. Distant heart procurement provides an expanded donor pool for potential cardiac recipients.

Coronary Vessels↗
PubMed1979

Diagnosis and treatment of acute cardiac allograft rejection.

Integration of data derived from immunologic monitoring techniques and endomyocardial biopsy currently permits more precise administration of immunosuppressive medications for the treatment of acute cardiac allograft rejection than was formerly possible, resulting in a substantially improved outlook for long-term survival. Indeed, the probability of survival for 5 years postoperatively of 50% exceeds that for several categories of cardiac patients currently undergoing other more common forms of heart surgery. The continuing demonstration of the potential for cardiac transplantation clearly warrants further application of this procedure for the treatment of appropriate patients with end-stage cardiac disease.

Adrenal Cortex Hormones↗
PubMed1979

Acute mitral valvular obstruction from infective endocarditis: echocardiographic diagnosis and report of the second successfully treated case.

Severe mitral stenosis of rapid onset and progression was observed in a patient with infective endocarditis superimposed upon mild rheumatic mitral valvular stenosis. This severe stenosis resulted from large vegetations impinging upon the mitral valve orifice. Preoperative studies indicating mitral stenosis with vegetations and pulmonary edema were followed by emergency mitral valve replacement, which was sucessful.

Acute Disease↗