Search PubMed⌕ Search

Biomedical subjects

R L Hardesty

Publications and source records attributed to R L Hardesty.

At least 37 records · Page 2Linked to original sources
PubMed1994

Lung transplantation at the University of Pittsburgh: 1982 to 1994.

Lung transplantation is a growing modality of treatment for patients with end-stage lung disease. In our program, survival has improved significantly in recent experience. Progress in candidate and donor selection, allograft preservation technique, recipient surgery, and postoperative management combine to reduce recipient morbidity and mortality. Although the tailored antibiotic treatment has significantly reduced the risk of bacterial pneumonia within 2 weeks after operation, infection is still a major cause of death for long-term recipients. Extensive studies need to be continued to understand the pathogenesis of OB and to establish the treatment for OB.

Adolescent↗
PubMed1994

Indications for and results of single, bilateral, and heart-lung transplantation for pulmonary hypertension.

The indications for single, bilateral, and heart-lung transplantation for patients with pulmonary hypertension remain controversial. We retrospectively analyzed the results from 11 single, 22 bilateral, and 24 heart-lung transplant procedures performed between January 1989 and January 1993 on 57 consecutive patients with pulmonary hypertension caused by primary pulmonary hypertension (n = 27) or Eisenmenger's syndrome (n = 30). Candidates with a left ventricular ejection fraction less than 35%, coronary artery disease, or Eisenmenger's syndrome caused by surgically irreparable complex congenital heart disease received heart-lung transplantation. All other candidates received single or bilateral lung transplantation according to donor availability. Although postoperative pulmonary artery pressures decreased in all three allograft groups, those in single lung recipients remained significantly higher than those in bilateral and heart-lung recipients. The cardiac index improved significantly in only the bilateral and heart-lung transplant recipients. A significant ventilation/perfusion mismatch occurred in the single lung recipients as compared with bilateral and heart-lung recipients because of preferential blood flow to the allograft. Graft-related mortality was significantly higher and overall functional recovery as assessed by New York Heart Association functional class was significantly lower at 1 year in the single as compared with bilateral and heart-lung recipients. Thus bilateral lung transplantation may be a more satisfactory option for patients with pulmonary hypertension with simple congenital heart disease, absent coronary arterial disease, and preserved left ventricular function. Other candidates will still require heart-lung transplantation.

Adolescent↗
PubMed1994

Anastomotic pitfalls in lung transplantation.

Although airway, arterial, and venous connections required for lung transplantation appear simple, in practice we have encountered morbid early stenosis and obstructions, which are now avoided by technical modifications gradually made since 1985 in 134 cases (60 single lung and 74 double lung). Our initial eight double lung transplant procedures were done with tracheal anastomoses and omental wraps, but ischemic disruption, with a 75% (6 of 8) rate of complications, resulted in the subsequent use of bi-bronchial connections. A total of 192 bronchial anastomoses were reviewed (60 single lung, 66 double lung). Although all anastomoses were constructed between the donor trimmed to one to two rings above the upper lobe origin and the host divided at its emergence from the mediastinum, the suture technique has evolved. Nine (32%) of 28 cases with early bronchial anastomoses with end-to-end suture and intercostal muscle wrap had ischemic or stenotic complications, but the telescoping technique without wrap in 164 bronchial anastomoses reduced the problem to 12% (19 of 164). Twelve anastomoses required temporary intraluminal stenting. Vascular anastomotic obstructions occurred in five arterial (excessive length 2, short allograft artery 1, restrictive suture or clot 2) and two venous (excessive length 1, restrictive suture or clot 1) connections. Suspicion of arterial obstruction was prompted by persisting pulmonary hypertension and reduced flow to the allograft measured by postoperative nuclear scan and hypoxia. Venous obstructions were suggested by persisting radiographic and clinical pulmonary edema. Modifications of earlier techniques have improved our early success in lung transplantation and might be considered by others entering this demanding field.

Anastomosis, Surgical↗
PubMed1993

Preoperative pulmonary hemodynamics and early mortality after orthotopic cardiac transplantation: the Pittsburgh experience.

The influence of preoperative transpulmonary pressure gradient (TPG) and pulmonary vascular resistance (PVR) on early post-transplant mortality was evaluated in 425 orthotopic transplant recipients. The overall 30-day post-transplant mortality rate was 12.5%; the majority of the deaths (52.8%) were due to primary allograft failure. The 0- to 2-day mortality rate was threefold higher in patients with severe preoperative pulmonary hypertension (TPG > or = 15 mm Hg or PVR > or = 5 Wood units), whereas the 3- to 7-day and 8- to 30-day mortality rates were similar. Early post-transplant mortality (0 to 2 days and 8 to 30 days) was also significantly higher (15.9% vs 3.9% and 9.9% vs 2.8%, respectively; p < 0.05) in women compared with men. Women with severe preoperative pulmonary hypertension had higher (p < 0.05) 0- to 2-day post-transplant mortality than comparable men. According to univariate analysis, recipients with preoperative TPG > or = 15 mm Hg had a significantly higher 30-day postoperative mortality rate, irrespective of their level of PVR. Furthermore, patients with severe preoperative pulmonary hypertension who underwent transplantation between 1980 and 1987 had a higher 0- to 2-day post-transplant mortality rate compared with patients operated on after that time. Multiple logistic regression analysis identified female recipient sex and preoperative TPG but not preoperative PVR, era of transplantation, or recipient age as significant (p < 0.001 and p < 0.01, respectively) independent predictors of early post-transplant mortality.

Adolescent↗
PubMed1993

A decade of lung transplantation.

OBJECTIVE: The experience accrued at the University of Pittsburgh between March 1982 and December 1992 in the various forms of lung transplantation, including heart-lung, double lung, and single lung, is discussed. SUMMARY BACKGROUND DATA: Heart-lung (n = 97) was the most commonly performed operation followed by double lung (n = 80) and single lung (n = 68). Major indications included primary pulmonary hypertension (n = 76), obstructive lung disease (n = 57), Eisenmenger's syndrome (n = 42), cystic fibrosis (n = 32), and retransplantation (n = 13). Since May 1991, 115 procedures have been performed and heart-lung transplantation has decreased from 61% to 15% of the cases with a corresponding doubling in double lung from 24% to 43% and single lung from 15% to 42%. RESULTS: The 1-, 2-, and 5-year survival rates in all 232 recipients were 61%, 55%, and 44%, respectively. The actuarial survival rate was significantly better for those 107 recent recipients compared to the 125 early recipients (70% vs. 61%). Overall, the 63 single (70%) and 74 double (65%) lung procedures were more successful than heart-lung transplantation (53%). Recently, however, lung transplantation has been associated with an improvement in the survival rate from 48% to 72%. The survival rate has also improved from 53% to 77% for single lung transplant recipients. The causes of death in 106 recipients included infection (n = 40), early allograft dysfunction (n = 23), obliterative bronchiolitis (n = 13), and inoperative bleeding (n = 10). Poor outcomes also included technical problems (n = 6), lymphoma (n = 4), acute rejection (n = 3), diaphragmatic paralysis (n = 2), multisystem organ failure (n = 2), stroke (n = 2), liver failure (n = 1), and airway dehiscence (n = 1). CONCLUSIONS: The long-term outlook for lung transplant recipients has improved. There appears to be significant conservation of organs with single lung and double lung transplantation, finding greater acceptance for diseases once exclusively treated by heart-lung transplantation alone. The improved long-term outlook will be dependent upon better treatment for chronic rejection of the airways that histologically is defined by obliterative bronchiolitis.

Adolescent↗
PubMed1993

Pediatric lung transplantation. The years 1985 to 1992 and the clinical trial of FK 506.

The application of lung transplantation to the pediatric population was a natural extension of the success realized in our adult transplantation program, which began in 1982. Twenty pediatric patients (age range 3 to 18 years) have had heart-lung (n = 11), double lung (n = 8), and single lung (n = 1) transplantation procedures. The causes of end-stage lung disease were primary pulmonary hypertension (n = 7), congenital heart disease (n = 5), cystic fibrosis (n = 4), pulmonary arteriovenous malformation (n = 2), graft-versus-host disease (n = 1), and desquamative interstitial pneumonitis (n = 1). Four (20%) patients had thoracic surgical procedures before the transplantation operation. The survival was 80% at a mean follow-up of 2 years. Immunosuppressive drugs included cyclosporine (n = 9) or FK 506 (n = 11) based therapy with azathioprine and steroids. Children were followed up by means of spirometry, transbronchial biopsy, and primed lymphocyte testing of bronchoalveolar lavage fluid. The mean number of treated episodes of rejection was 1.4 at 30 days, 0.5 at 30 to 90 days, and 1.4 at more than 90 days, and the first treated rejection episode occurred on average 28 days after the operation. Obliterative bronchiolitis developed in four (25%) of 16 patients surviving more than 100 days. Results of pulmonary function tests have remained good in almost all recipients. The greatest infectious risk was that of cytomegalovirus: one death and one case of pneumonia. Posttransplantation lymphoproliferative disease was diagnosed in two (12.5%) patients; both recovered. The most common complications were hypertension (25%) and postoperative bleeding (15%). Early results indicate that lung transplantation is a most promising therapy for children with severe vascular and parenchymal lung disease.

Adolescent↗
PubMed1993

A decade (1982 to 1992) of pediatric cardiac transplantation and the impact of FK 506 immunosuppression.

The decade from 1982 through 1992 witnessed tremendous growth in pediatric cardiac transplantation. At Children's Hospital of Pittsburgh 66 cardiac transplants were performed during this period (age range 7 hours to 18 years). The cause of cardiomyopathy was congenital (n = 30), cardiomyopathy (n = 29), myocarditis (n = 2), doxorubicin toxicity (n = 2), ischemic (n = 1), valvular (n = 1), and cardiac angiosarcoma (n = 1). Nine children (14%) required mechanical circulatory support before transplantation: extracorporeal membrane oxygenation (n = 8) and Novacor left ventricular assist system (n = 1) (Baxter Healthcare Corp., Novacor Div., Oakland, Calif.). The mean follow-up time was 2 years (range 4 months to 8 years). The overall survival in the group was 67%. In children with congenital heart disease (> 6 months of age) the perioperative (30 day) mortality was 66% before mid-1988 (n = 10) and 0% since mid-1988 (n = 11). The late mortality (> 30 days) in children with cardiomyopathy transplanted prior to mid-1988 was 66% (n = 14) and 7% since mid-1988 (n = 15). Since mid-1988 1- and 3-year survival was 82% in children with congenital heart disease and 90% in children with cardiomyopathy. Twenty-six children have had FK 506 as their primary immunosuppressive therapy since November 1989. Survival in this group was 82% at 1 and 3 years. The actuarial freedom from grade 3A rejection in the FK group was 60% at 3 and 6 months after transplantation versus 20% and 12%, respectively, in the 15 children operated on before the advent of FK 506, who were treated with cyclosporine-based triple-drug therapy (p < 0.001, Mantel-Cox and Breslow). Twenty of 24 children (83%) in the FK 506 group are receiving no steroids. The prevalence of posttransplantation hypertension was 4% in the FK 506 group versus 70% in the cyclosporine group (p < 0.001, Fisher). Renal toxicity in children treated with FK 506 has been mild. Additionally, eight children have been switched to FK 506 because of refractory rejection and drug toxicity. FK 506 has not produced hirsutism, gingival hyperplasia, or abnormal facial bone growth. The absence of these debilitating side effects, together with the observed immune advantage and steroid-sparing effects of FK 506, hold tremendous promise for the young patient facing cardiac transplantation and a future wedded to immunosuppression.

Adolescent↗
PubMed1993

Improved survival following pediatric cardiac transplantation in high-risk patients.

BACKGROUND: Preoperative hemodynamic support, complex congenital heart disease, and elevated pulmonary vascular resistance present particular challenges for pediatric heart transplantation. This study was performed to identify preoperative factors that influence survival after pediatric heart transplantation over two eras of pediatric heart transplant experience. METHODS AND RESULTS: We retrospectively analyzed demographic, clinical, and hemodynamic data from 67 pediatric patients who underwent heart transplantation between February 1982 and June 1992 and compared survival between two eras (early experience versus late experience). During the early experience (group 1: February 1982 to August 1989), univariate analysis identified congenital heart disease, pretransplant extracorporeal membrane oxygenator (ECMO) support, inotropic and/or ventilatory support (UNOS status I), elevated transpulmonary gradient (at least 15 mm Hg), and elevated pulmonary vascular resistance index (at least 4 Wood units.m2) as preoperative risk factors for early death after pediatric heart transplantation. However, in the late experience (group 2: September 1989 to June 1992), the only risk factor for premature death by univariate analysis was elevated transpulmonary gradient. By multivariate analysis, elevated transpulmonary gradient was the only risk factor for our early, late, and entire experiences. One-year survival after transplantation for congenital heart disease was improved from 46% in group 1 to 73% in group 2 (P < .05). In group 1, only one patient (25%) with pretransplant ECMO support survived 1 year, whereas 66% (four of six) survived more than 1 year in group 2. CONCLUSIONS: Although elevated transpulmonary gradient continues to be a significant risk factor for pediatric heart transplantation, candidates with congenital heart disease, UNOS status I, and pretransplant ECMO support now can be successfully transplanted with reasonable hope for extended survival.

Cardiomyopathies↗
PubMed1993

Isolated lung transplantation for patients with Eisenmenger's syndrome.

BACKGROUND: Eisenmenger's syndrome remains one of the greatest challenges in lung transplantation. METHODS AND RESULTS: Since October 1990, seven such patients with Eisenmenger's syndrome received isolated pulmonary grafts (six double lungs and one single lung). Mean patient age was 32 +/- 6 years (two men and five women). The preoperative mean pulmonary arterial pressure was 90.7 +/- 31.2 mm Hg, and the ventriculoscintigram showed markedly enlarged right ventricle and normal left ventricular function with ejection fraction of 0.660 +/- 0.115. Three atrial septal defects and four patent ducti arteriosus were repaired concomitantly. Excised lung histology showed plexogenic pulmonary arteriopathy with Heath-Edwards' grade 4 through 6. One double lung patient who had preexisting systemic vascular collapse died intraoperatively. The other six patients tolerated transplantation, and on the first operative day, mean pulmonary artery pressure decreased to 22.4 +/- 7.3 mm Hg (P < .002) and gas exchange was acceptable with an arterial/alveolar oxygen tension ratio of 0.47 +/- 0.15. Two patients died of mediastinal and pulmonary infection. The follow-up for the four survivors ranged from 13 to 25 months after transplantation. CONCLUSIONS: Our preliminary experience shows that concomitant isolated lung transplantation with cardiac repair could be a viable therapeutic option for patients with Eisenmenger's syndrome and normal left ventricular function. Dynamic right ventricular outflow obstruction is a potential hemodynamic problem in these pulmonary recipients.

Adult↗
PubMed1993

A clinical trial of University of Wisconsin solution for pulmonary preservation.

Suboptimal pulmonary preservation with modified Euro-Collins solution (9/90 to 4/91) prompted us to change to University of Wisconsin solution (4/91 to 4/92). Between September 1990 and April 1992, 94 patients received 100 pulmonary allografts (13 heart-lungs, 45 double lungs, 42 single lungs) that were flushed and preserved with either Euro-Collins (n = 30) or University of Wisconsin (n = 70) solution. Selection of donors and procurement and storage of donor lungs were identical. Bilateral single lung transplantation was performed more often in the University of Wisconsin group and resulted in a significantly longer graft ischemic time (University of Wisconsin group; 303 +/- 62 minutes; Euro-Collins group; 260 +/- 62 minutes; p = 0.007, t test). The use of cardiopulmonary bypass was not statistically significantly different. Preservation injury identified by the radiograph on day 1 was more severe (p = 0.036; Mann-Whitney U test) in the Euro-Collins group than in the University of Wisconsin group. In double lung and heart-lung recipients gas exchange of the allografts was evaluated by the arterial/alveolar oxygen tension ratios at nine intervals during the first 72 hours. The mean arterial/alveolar oxygen tension ratio was 0.62 +/- 0.26 in the University of Wisconsin group and 0.46 +/- 0.23 in the Euro-Collins group, but this difference did not reach significance (p = 0.119, analysis of variance). Despite the longer ischemic time, pulmonary preservation achieved by University of Wisconsin solution appears to be comparable with that achieved by Euro-Collins solution.

Adenosine↗
PubMed1992

Psychosocial outcome six months after heart transplant surgery: a preliminary report.

With improvement in survival of patients treated with heart transplant, evaluation of recovery with respect to psychosocial function has become an important issue. In this study, psychosocial functioning of 44 heart transplant recipients pretransplant was compared to their functioning 6 months posttransplant. Before transplantation, patients experienced considerable psychosocial distress attributable to illness. At 6 months after transplantation, the majority of patients showed significant improvement in emotional, domestic, sexual, social, and vocational functioning. However, 25% of patients showed deterioration in psychosocial adjustment and 11% showed an increase in mood disturbance. Further effort is indicated to improve psychosocial outcome of heart transplantation.

Adaptation, Psychological↗
PubMed1992

Acute rejection of lung allografts with various immunosuppressive protocols.

Between February 1990 and December 1991, 69 patients who survived for a minimum of 5 days after single-lung (27), double-lung (32), or heart-lung transplantation (10) were studied to learn the incidence and severity of acute rejection and the possible effects of various immunosuppressive protocols on this rejection. Acute rejection was less common (2.1 versus 3.1 episodes/patient) after transplantation in those 30 candidates who received rabbit antithymocyte globulin for the first 5 postoperative days versus the 28 who were maintained on cyclosporine, azathioprine, and prednisone alone (p < 0.05), but no patient escaped at least one episode. Patients given cyclosporine received more 3-day courses of methylprednisolone (p < 0.02) than those given rabbit antithymocyte globulin (2.5 versus 1.7 courses). Although no disadvantage in terms of infectious morbidity was noted in the rabbit antithymocyte globulin group, no obvious intermediate advantage was noted in survival (85% at 12 months) or grade of rejection or airway flows. The most common histopathologic grades were mild (A2) and moderate (A3); the average grade was A2.3. FK 506 was tested in 11 patients, and early results are promising relative to low early and likely fewer late episodes of rejection. No differences were noted in the likelihood of rejection for any procedures.

Acute Disease↗
PubMed1992

University of Wisconsin solution for pulmonary preservation in a rat transplant model.

University of Wisconsin and modified Euro-Collins solutions for pulmonary preservation were compared in a rat orthotopic left lung isotransplant model. Heart-lung blocks of donor rats were flushed with and preserved in one of the preservation solutions at 0 degrees C. After 6 or 12 hours of cold ischemia, the left lungs were transplanted into recipient rats and reperfused for 1 hour. Pulmonary function was assessed by measuring oxygen and carbon dioxide tensions in arterial blood after removal of the right lung. Lipid peroxide concentrations were measured as thiobarbiturate acid-reactive substances. The ratios of wet to dry weight of grafts after ischemia and after reperfusion were calculated. Histologic changes of ischemia-reperfusion injury of the lung tissue were evaluated using a graded scale. Oxygen tension after 6 hours of preservation followed by reperfusion was significantly higher with University of Wisconsin solution (308.8 +/- 81.1 mm Hg) than with Euro-Collins solution (50.8 +/- 17.8 mm Hg; p less than 0.001). Carbon dioxide tension in the University of Wisconsin solution group was also significantly lower than in the Euro-Collins solution group (28.2 +/- 2.3 versus 46.0 +/- 4.5 mm Hg; p less than 0.05). Lipid peroxide concentration after 6 hours' preservation in University of Wisconsin solution was significantly lower (0.88 +/- 0.07 mumol/g) than that in Euro-Collins solution (1.26 +/- 0.12 mumol/g; p less than 0.05). After 12 hours of preservation only lipid peroxide concentration with University of Wisconsin solution was significantly lower (1.30 +/- 0.09 mumol/g) than with Euro-Collins solution (1.71 +/- 0.15 mumol/g; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗
PubMed1992

Prolonged intraaortic balloon support for septal rupture after myocardial infarction.

Timing of surgical repair of ventricular septal defect developing after acute myocardial infarction remains controversial. We report the case of a 75-year-old man in whom a ventricular septal defect developed 7 days after myocardial infarction. The patient was maintained on intraaortic balloon pump support for 33 days before successful surgical closure. In the present era of aggressive preoperative hemodynamic management, the strategy of prolonged support before definitive operation on patients with myocardial infarction in whom a ventricular septal defect develops must be reconsidered.

Aged↗
PubMed1992

Clinical trial of FK 506 immunosuppression in adult cardiac transplantation.

The new immunosuppressive agent FK 506 was used as primary immunotherapy in conjunction with low-dose steroids and azathioprine in 72 patients subsequent to orthotopic cardiac transplantation. Overall patient survival at a mean follow-up of 360 days was 92%. The number of episodes of cardiac rejection (grade 3A or greater) within 90 days of transplantation was 0.95 per patient. The actuarial freedom from rejection at 90 days was 41%. Achievement of this level of immunosuppression is comparable with that of cyclosporine-based triple-drug therapy with OKT3 immunoprophylaxis. Thirty percent of patients were tapered off all steroids, and the average steroid dose in the group who received steroids was 8.6 mg of prednisone per day. The incidence of infection reflected the diminished necessity for steroids: seven major infections (10%) and 11 minor infections (16%). Renal dysfunction occurred during the perioperative period in most patients in this trial. However, the incidence of hypertension was 54% compared with 70% during the cyclosporine era. Ten adults underwent successful rescue therapy with FK 506 after cardiac rejection refractory to conventional immunotherapy. Side effects of FK 506 were notably few, and the results of the trial are encouraging for the future of the cardiac transplant recipient.

Adult↗
PubMed1992

Ganciclovir prophylaxis for cytomegalovirus infections in pulmonary allograft recipients.

Cytomegalovirus (CMV) is a substantial cause of morbidity in pulmonary allograft recipients. In an attempt to decrease the prevalence of this infection, we treated 13 recipients at risk for cytomegalovirus with 3 wk of intravenous ganciclovir (5 mg/kg twice a day for 14 days, starting 5 days after the procedure, followed by 1 wk of the drug at a dose of 5 mg/kg/day). Following the ganciclovir course, patients received oral acyclovir, 800 mg three times a day for at least 2 months more. CMV infections developed in 5 recipients (38%), and none of these episodes occurred during the ganciclovir therapy. Neither of the 2 deaths in this group could be attributed to CMV. In comparison, the prevalence of CMV in the preceding cohort of 11 transplant recipients who were administered acyclovir alone was 91% (p << 0.01 by log-rank test), and there were 3 deaths due to viral infections (p = 0.08 by Fisher's exact test). Groups were similar in terms of immunosuppression and renal function during treatment, and none of the recipients developed leukopenia. We conclude that ganciclovir prophylaxis is well tolerated and appears to have considerable efficacy for prevention of CMV infections in pulmonary transplant recipients.

Administration, Oral↗
PubMed1992

Efficacy of antihypertensive medication in orthotopic heart transplant recipients and its effect on renal function.

The authors looked at 77 patients following orthotopic heart transplant who received a triple immunosuppressive regimen including cyclosporine to see the effect of various antihypertensive medications on mean arterial blood pressure and renal function. There were 62 men and 15 women retrospectively classified into three groups according to the antihypertensive medications they received. Group 1 included 26 patients followed up for 10.7 +/- 2.7 months who received hydralazine therapy. Group 2 included 32 patients followed up for 9.0 +/- 3.4 months who received angiotensin-converting enzyme inhibition therapy. Group 3 included 19 patients followed up for 10.1 +/- 3.3 months who received beta-adrenergic blocking agents. Mean arterial pressure (MAP), serum blood urea nitrogen (BUN), and serum creatinine (CR) were determined for each group at the start and end of the follow-up period. The MAP at the start of the study was 107 +/- 14 in group 1, 110 +/- 13 in group 2, and 100 +/- 11 in group 3. It was not statistically significantly different in any of the groups. At the end of the follow-up period, MAP was 112 +/- 10, 111 +/- 10, and 106 +/- 12 for the three groups respectively, and it was not significantly different in any group. The serum BUN in group 3 was 25 +/- 8 mg/dL at the start of the study, and it was not significantly lower than that in group 1, 28 +/- 6, but it was significantly different from that in group 2, 34 +/- 9, P less than 0.05. At the end of the follow-up period, the difference was still maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗