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Biomedical subjects

R L Hardesty

Publications and source records attributed to R L Hardesty.

At least 109 records · Page 6Linked to original sources
PubMed1987

Temporary use of the Jarvik-7 total artificial heart before transplantation.

Between October 24, 1985, and July 31, 1986, the Jarvik-7 total artificial heart was implanted into six moribund patients in an attempt to test its potential as a bridge from almost certain death to cardiac transplantation. Four of these patients are now well and at home after implantation of the device and subsequent cardiac transplantation. Before transplantation, one patient died with sepsis and multiorgan failure that preceded implantation of the artificial heart. Another patient died with acute rejection 60 days after cardiac transplantation. Fifty-two days of total mechanical support with the artificial heart were accumulated in these six patients, and although the device worked flawlessly and no clinically apparent thromboembolic events occurred, each artificial heart contained areas of macroscopic aggregations of platelets and thrombi. The results of this trial indicate that in properly selected cases, direct benefit to the patient can be obtained when the Jarvik-7 artificial heart is used as a bridge to transplantation.

Adult↗
PubMed1987

Heart-lung transplantation: lessons learned and future hopes.

Since March, 1982, 33 patients have undergone cardiopulmonary transplantation. Nineteen were discharged from the hospital following the operation, and 16 continue to do well. Eight patients have survived 1 year, 5 patients 2 years, and 1 patient 3 years. Often survival has been influenced most by the selection of candidates, as no patient who had undergone a previous sternotomy survived (3 of 3). All 7 early (between 30 and 72 days) and 3 late (145 to 466 days) deaths were related to infection. Methods for ex vivo preservation of the heart-lung bloc have included storage at 4 degrees C, cardiopulmonary bypass and profound hypothermia, and autoperfusion of the heart-lung bloc. The last technique is original and currently is preferred for distant procurement. Because dehiscence of the tracheal anastomosis has occurred in 3 patients, a sutured line is now encircled with a wrap of omentum. Isolated rejection of the lung is frequent in the first three weeks following operation and has been controlled with methylprednisolone. Late survivors have shown a mild restrictive lung disorder that has not progressed between 6 and 24 months. Bronchoalveolar lavage has been useful for diagnosing infection and providing insight into the immunobiology of the transplanted lung. Although mortality and morbidity have been high, the experiences gained through this series will likely result in an improved outlook for future recipients.

Adolescent↗
PubMed1987

Early and late forms of cyclosporine nephrotoxicity: studies in cardiac transplant recipients.

To characterize the two forms of cyclosporine nephrotoxicity, we examined renal function in the immediate and late postoperative periods after cardiac transplantation. Moderate azotemia occurred during the first postoperative week in 58% of 43 cyclosporine-treated recipients, but in only 34% of 41 azathioprine-treated recipients, and 4% of 25 patients undergoing cardiopulmonary bypass for nontransplant surgery (both P less than .01 v cyclosporine). Acute renal failure developed in an additional 12% of the cyclosporine-treated group. Late postoperative renal dysfunction also occurred with a high prevalence. Life-table analysis indicated that at 6 months 55%, at 12 months 17%, at 24 months 4%, and at 36 months no cyclosporine-treated recipients retained normal renal function. Three renal biopsies performed in subjects with late nephrotoxicity demonstrated prominent interstitial fibrosis. Although one patient subsequently required chronic dialysis, reduction of cyclosporine dosage from a mean of 5.3 +/- 0.7 mg/kg/d to a mean of 2.3 +/- 0.3 mg/kg/d 9 to 21 months after transplantation with concurrent initiation of azathioprine therapy to prevent rejection led to an improvement of renal function in the five patients so treated. These data indicate that there are two distinct forms of cyclosporine nephrotoxicity. Although both occur with high prevalence, the early form does not appear to be a specific risk factor for the late form.

Acute Kidney Injury↗
PubMed1987

Heterotopic cardiac transplantation: current status.

Heterotopic cardiac transplantation first introduced by Bernard in 1974 currently is rarely used as the procedure of choice when orthotopic cardiac transplantation can be considered. Specific indications for heterotopic cardiac transplantation include elevation of pulmonary vascular resistance and availability of a small or poorly functioning donor organ for a mortally ill recipient. Most cardiac transplant centers have abandoned its routine use because the recipient's diseased and poorly functioning heart remains as a potential source for embolism, infection, and continued angina, because the operative procedure is more complicated. Pulmonary complications are common due to compressive atelectasis of the right lung. Experience indicates that the heterotopic procedure is useful for those selected individuals in whom the orthotopic procedure is not appropriate and that rates of survival are nearly equal.

Anastomosis, Surgical↗
PubMed1987

Development of coronary artery disease in cardiac transplant patients receiving immunosuppressive therapy with cyclosporine and prednisone.

Coronary artery disease (CAD) has been shown in previous uncontrolled studies to be a limiting factor to long-term survival in patients undergoing cardiac transplantation and who were taking conventional immunosuppressive agents. To study the development of CAD after cardiac transplantation in patients taking the newer immunosuppressive agent cyclosporine, we prospectively performed yearly coronary arteriography on all eligible transplantation patients (first year, 57 patients; second year, 30 patients; third year, 14 patients). The prevalence of CAD by life table analysis was 18% at 1 year, 27% at 2 years, and 44% at 3 years. The occurrence of two or more major rejection episodes was associated (p less than .005) with the development of CAD. In two patients who died of CAD, coronary artery histology revealed subintimal inflammatory cellular infiltration in some lesions. These data demonstrate that the prevalence of CAD rises progressively over time and immunologic factors may be important in its development.

Adult↗
PubMed1987

Cardiac transplantation: improved quality of survival with a modified immunosuppressive protocol.

The effects on renal function on two different immunosuppressive protocols were evaluated retrospectively in two subsequent groups of heart transplant recipients. In group I, cyclosporine was given before the procedure at a loading dose of 17.5 mg/kg and then continued after the procedure to keep a whole blood level about 1000 ng/ml. In group II, cyclosporine was started only after the procedure at a lower dosage and was complemented by azathioprine, which was used for the first postoperative week. Group II showed a better perioperative renal function as determined by serum blood urea nitrogen and serum creatinine levels. Group II also showed a significant decrease of chronic nephrotoxicity secondary to long-term therapy with cyclosporine. Despite this improvement in late renal function, group II still shows a slow rise in serum creatinine. We think that even these lower dosages of cyclosporine can cause chronic nephrotoxicity and that further modification of the immunosuppressive regimen is required to completely abolish this toxic side effect.

Actuarial Analysis↗
PubMed1987

Autoperfusion of the heart and lungs for preservation during distant procurement.

A modified autoperfusing Starling preparation was used to provide pulmonary and coronary blood flow to extend the period of preservation for heart-lung transplantation. Twenty successful donations were achieved, 14 performed, and both the heart and lungs were well preserved in 14 of them. In four recipients it was not possible to assess the adequacy of preservation. In one recipient the preservation was not satisfactory, and in another the selection of the donor was responsible for poor cardiac function. Ten patients are alive who would not be were it not for this technique.

Adolescent↗
PubMed1987

Experience with heart transplantation in children.

Between March 1981 and March 1986, 200 orthotopic heart transplantations were performed at the University of Pittsburgh. Fourteen of those procedures were carried out in children 2 to 16 years of age. Two children received combined liver and heart transplants; one because of familial hypercholesterolemia with associated ischemic heart disease, and the other because of dilated cardiomyopathy associated with intrahepatic biliary atresia. Eight patients had dilated cardiomyopathy, and two had myocarditis. Two had heart transplantations for congenital heart disease: one had multiple muscular ventricular septal defects repaired in infancy and had an associated cardiomyopathy, and the other developed a cardiomyopathic ventricle from a congenital right coronary artery to right atrial fistula. Chronic immune suppression consisted 0.2 to 0.5 mg/kg/d of prednisone and 5 to 50 mg/kg/d cyclosporine, with the addition of antithymocyte globulin for unresolved moderate or severe acute rejection. There were three early postoperative deaths: one from intracranial bleeding, one from Pseudomonas mediastinitis, and one from ischemic injury to transplanted organs. Early postoperative complications included reversible renal failure, hypertension, and seizures. Late problems were related to allograft rejection and side effects of cyclosporine and corticosteroids. Significant rejection episodes occurred in all patients surviving longer than 2 weeks, with seven requiring antithymocyte globulin. Two patients died 8 months following transplantation of severe acute and chronic rejection; another patient required retransplantation for ischemic cardiomyopathy resulting from chronic rejection but subsequently died of recurring rejection 3 months after the second transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

The contrasting effects of cyclosporin-A and azathioprine on arterial blood pressure and renal function following cardiac transplantation.

The effects of cyclosporin-A and azathioprine on the postoperative development of systemic hypertension and renal dysfunction in patients undergoing cardiac transplantation were compared retrospectively in 18 patients receiving cyclosporin-A and in 12 patients receiving azathioprine. Twelve months postoperatively, the average mean blood pressure was 116 +/- 13 mm Hg and 98 +/- 7.5 mm Hg; the average preoperative serum creatinine was 1.2 +/- 0.3 mg% and 1.5 +/- 0.3 mg%; and the postoperative serum creatinine was 2.2 +/- 0.8 mg% and 1.1 +/- 0.2 mg% (P less than 0.0001) in the cyclosporin-A-and azathioprine-treated groups respectively. Hemodynamic studies were done to characterize the de novo postoperative hypertension developing in the cyclosporin-A group. The pre- and postoperative cardiac output was 3.7 and 4.91/min, respectively (P less than 0.01). The pre- and postoperative systemic vascular resistance was 1707 and 1941 dynes sec X cm-5, respectively (P greater than 0.2). Peripheral renin activity and 24-hour urinary catecholamine excretion were not elevated. The mechanism of the hypertension developing in cyclosporin-A-treated patients is unknown, but is associated with normalization of cardiac output, an abnormally elevated systemic vascular resistance, and modest impairment of renal function. These findings are in marked contrast to azathioprine-treated patients, in whom postoperative hypertension and renal dysfunction do not occur. These observations implicate cyclosporin-A as the major contributing factor in the development of hypertension and renal dysfunction.

Adult↗
PubMed1986

Extracorporeal membrane oxygenation experience at the University of Pittsburgh.

Between January, 1981, and May, 1985, 33 infants suffering from acute cardiorespiratory failure were treated with extracorporeal membrane oxygenation (ECMO) when all other forms of conventional management had failed. Only the patients with respiratory failure that was thought to be reversible were treated. Prolonged conventional respiratory management (more than five days) was considered a contraindication to ECMO support because of irreversible damage to the lungs caused by the barotrauma associated with conventional ventilation. Eighteen of the 33 patients (54%) survived and were discharged from the hospital. Patients with congenital diaphragmatic hernia had a high incidence of fatal bleeding complications (8 of 14). Good results were obtained in the newborns with persistent fetal circulation and meconium aspiration syndrome. We conclude that ECMO markedly improves the survival of newborns with severe respiratory failure who would have a mortality close to 100% with conventional respiratory management.

Acute Disease↗
PubMed1986

Mortally ill patients and excellent survival following cardiac transplantation.

Cardiac transplantation was resumed in 1980 at the University Health Center of Pittsburgh. Generally accepted criteria for selection of patients were used, one being the expectation that survival would not reach 6 months. All of the initial recipients were in New York Heart Association Functional Class IV, but many were ambulant. We soon saw patients who were more clearly terminally ill. They were characterized by a systolic arterial pressure of less than 80 mm Hg, a cardiac index of less than 2 L/min/m2, evidence of reduced blood flow as indicated by urine output of less than 20 ml per hour, impaired mental function, and signs of decreased peripheral perfusion. The initial success of cardiac transplantation in these patients prompted us to reconsider selection criteria to include them among less strikingly ill candidates and to develop a therapeutic protocol designed to maintain peripheral perfusion and adequate renal and hepatic function until transplantation could be accomplished. Actuarial survival at 30 months for the group of terminally ill patients was 75% compared with 67% for the less critically ill group. Actuarial survival at 30 months for the combined group of 77 patients was 67%. Twenty-nine of the 33 mortally ill patients were alive and active at the time of writing, January, 1985.

Adult↗
PubMed1986

Development and organization of a multiple organ transplantation program.

Multiple organ transplantation has come of age. Indications are that it will continue to grow, if not flourish. The complexity of modern surgical care, its multiperson dependency, and the need for the surgeon to retain knowledge and involvement with his patient's care and problems are nowhere more evident than in multiple organ transplantation. Each organ presents its own associated challenges, the prime solution of which lies with a skillful and dedicated surgeon; but with all organs there are challenges of expectantly waiting patients, housing during the wait and for postoperative observation, procurement, erratic scheduling of the operating room, nursing, social service, immunosuppression, immunopathology, interest of hospital public relations and of the news media, and perennial care. This report concerns the growth and development of the multiple organ transplant program at the University Health Center of Pittsburgh and describes some answers to the challenges presented.

Academic Medical Centers↗