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Biomedical subjects

B Radovancevic

Publications and source records attributed to B Radovancevic.

108 records · Page 6Linked to original sources
PubMedDate not supplied

Successful bridge to heart transplantation with a new left ventricular assist device.

During the last 5 years, a new pneumatically driven left ventricular assist device has been implanted in 18 heart transplantation candidates who required advanced mechanical circulatory support. The mean duration of support was 80 +/- 74 days, and the cumulative support time was 1400 days. Fifteen patients were successfully supported until the time of heart transplantation. As a result of early experience, in which three of four patients died after heart transplantation because their end-organ function failed to recover, subsequent efforts were made to institute support early, before irreversible organ damage occurred. Eleven of the 12 patients in the later experience are currently alive and well at a mean follow-up of 12.6 +/- 7.5 months. No thromboembolic episodes occurred, and minimal anticoagulation was required. Furthermore, patients were able to participate in rehabilitative exercise programs, thus optimizing their transplantation status. Finally, the findings in these patients have shown the feasibility of providing long-term, or even permanent, cardiac assistance.

Adult↗
PubMedDate not supplied

Bacterial mediastinitis after heart transplantation.

Bacterial mediastinal abscess or mediastinitis developed in nine (2.5%) of 361 consecutive patients who underwent isolated heart transplantation at the Texas Heart Institute. All nine patients had at least one predisposing factor that may have contributed to the development of mediastinitis. These included insulin-dependent diabetes mellitus, repeat operation for postoperative mediastinal hemorrhage, Staphylococcus aureus pneumonitis, and cardiac allograft rejection in the early postoperative period (less than 30 days), necessitating steroid pulse therapy alone or in combination with murine-derived monoclonal antibody (OKT3). In six of the nine patients, the diagnosis of mediastinitis was made on the basis of clinical findings (unstable sternum and incisional erythema, with or without gross purulence), and in the other three patients, diagnosis was confirmed by computed tomography of the chest. Culture data were unequivocal in all patients; S. aureus was the most frequent (five patients), followed by S. epidermidis (two patients), and Enterobacter cloacae (two patients). Computed tomography-directed percutaneous drainage and systemic antibiotics were successful in treating two of three patients who had stable sternums with mediastinal abscess. In the remaining seven patients, sternal and mediastinal debridement with rewiring of the sternum was successfully applied. No patient required muscle or omental flap coverage, and no patient experienced a recurrence of mediastinitis during an average follow-up period of 35 months (range, 12 to 46 months).

Female↗
PubMedDate not supplied

Frequency and significance of infections in patients receiving prolonged LVAD support.

Infections in patients undergoing mechanical circulatory support as a bridge to transplant are associated with significant mortality and morbidity. To determine the frequency and effects of infection during such procedures, a retrospective analysis was done of 14 patients who received prolonged (greater than 14 days) support with the Heartmate left ventricular assist device (LVAD) (Thermo Cardiosystems, Inc., Woburn, MA). All patients were men (mean age, 44.3 years), and duration of LVAD support ranged from 19 to 233 days (mean, 98.1 days). During LVAD support, five patients had no infections, and, in the remaining nine patients, infections were most common in the respiratory tract, catheter tips, and urine. Four device related infections occurred in three patients, all of which were resolved with antibiotic therapy. All 14 patients underwent transplantations, and none of the operations was delayed because of infection. Eleven of the patients are long-term survivors (range of time after transplant, 7.5-37 months). Infections were not associated with mortality or significant morbidity in this group of patients.

Adult↗
PubMedDate not supplied

Quality of life in long-term survivors of the Hemopump left ventricular assist device.

The courses of 10 patients (nine men and one woman; mean age, 54 years) were reviewed to determine the long-term results of treatment with the Hemopump (Nimbus Medical, Inc., Rancho Cordova, CA) left ventricular assist device. Indications for treatment were postcardiotomy cardiogenic shock (n = 8) and acute cardiac allograft rejection (n = 2). Two of the patients with postcardiotomy shock required a bridge to transplantation. At follow-up (mean, 21 months), eight patients were alive: four were in New York Heart Association Functional Class I and four were in Class II. None had long-term adverse effects that were attributable to the site of insertion (e.g., limb ischemia or infected groin wounds). All the patients considered themselves independent in their daily activities, and most of the patients were able to exercise and pursue hobbies. The Hemopump appears to offer long-term survival with an acceptable quality of life to a population of patients whose survival would have been highly unlikely otherwise.

Activities of Daily Living↗
PubMedDate not supplied

Extended support with a left ventricular assist device as a bridge to heart transplantation.

The Heartmate-1000IP, an intracorporeal, pneumatically activated, pulsatile left ventricular assist device (LVAD) with textured blood-contacting surfaces, is undergoing clinical evaluation as a bridge to heart transplantation (HTx). During a 3 year period (January 1988 to April 1991), the authors evaluated 12 patients who required extended LVAD support (greater than 30 days) while awaiting HTx. Duration of support ranged from 31 to 233 days (mean, 117 days). LVAD performance was excellent, with average pump flow indices of 2.5-3.5 L/min/m2. Long-term antithrombotic therapy consisted of dipyridamole and aspirin in all except one patient who received only low-molecular-weight dextran. After the initial recovery period, prothrombin and partial thromboplastin times returned to baseline levels. Plasma-free hemoglobin levels averaged less than 10 mg/dl. One patient is currently receiving support (91+ days); the 11 other patients underwent successful HTx, with follow-up ranging from 7 to 36 months. The authors' cumulative experience with this LVAD totals more than 1,506 days of support (greater than 4 years) without evidence of any thromboembolic episodes. These results suggest that this LVAD provides an effective bridge to HTx for extended periods.

Adult↗
PubMedDate not supplied

The development of a clinically relevant canine model of postperfusion syndrome.

Investigation into the complex etiology of the postperfusion syndrome (PPS) has been limited by access to only retrospective human case studies, and performance of animal studies that examine biochemical predictors of injury rather than the PPS itself. To determine whether a reproducible canine model of the clinical syndrome was possible, seven dogs underwent cardiopulmonary bypass (CPB) with a bubble oxygenator for 0 (n = 1, sham), 2 (n = 1), 4 (n = 1), and 6 (n = 4) hours. Arterial oxygenation, chest radiographs, serum creatinine, and total leukocyte and platelet counts continued to change through the second postoperative day, illustrating the need for prolonged follow-up (48 hours) to accurately detect postperfusion organ dysfunction. The dogs that did not undergo CPB for 6 hours (n = 3) did not develop important pulmonary dysfunction postoperatively, but three of the four dogs undergoing 6 hours of CPB developed profound, persistent, arterial hypoxemia associated with radiographic, histologic, and hemodynamic evidence of severe PPS. Early evidence of renal dysfunction was also apparent within 84 hours of 6 hour CPB. It is concluded that the canine long duration (6 hour) CPB model, with prolonged (48 hour) postoperative monitoring, generates a reproducible, clinically relevant model of human PPS.

Animals↗
PubMedDate not supplied

Adjuvant native heart surgery during heterotopic heart transplantation: two case reports.

The results of heterotopic heart transplantation may be further improved if repairs on native heart abnormalities are performed just before implantation of the allograft. Such procedures increase the potential for the recipient's own heart to recover function and, thus, to maintain circulation if the heterotopic heart malfunctions or fails. The native hearts of two of our patients, both women, showed signs of greater contractility and ejection after repair and were able to provide adequate circulatory support during periods of donor heart failure. The first patient required ventricular aneurysmectomy and coronary artery bypass grafting, and the second, native mitral valve repair. Moreover, when persistent ventricular fibrillation occurred in the donor heart of the first patient, a donor cardiectomy was performed, and the recipient heart functioned well thereafter. As more adjuvant operations are performed and the results evaluated, we may find that heterotopic operations would be suitable in a greater variety of heart transplant candidates.

Coronary Artery Bypass↗
PubMedDate not supplied

Coronary artery bypass two years after orthotopic heart transplantation: a case report.

Complete occlusion of the left anterior descending and right coronary arteries developed in a 58-year-old man 2 years after orthotopic heart transplantation. Because of his progressive shortness of breath, reversible myocardial ischemia, and decreasing ejection fraction, aortocoronary bypass was recommended. The operation was performed without complications, and his postoperative ejection fraction improved by more than 58%. In the past, when coronary artery disease developed in cardiac allografts, another transplant procedure was the only treatment option. Because of the limited donor hearts available today, new strategies are necessary for the treatment of cardiac allograft atherosclerosis.

Coronary Artery Bypass↗
PubMedDate not supplied

Impact of long-term cyclosporine immunosuppressive therapy on native kidneys versus renal allografts: serial renal function in heart and kidney transplant recipients.

Aggregate analyses of the impact of long-term cyclosporine administration in kidney transplant recipients have reported generally impaired but stable allograft function. In contrast, experience in extrarenal transplantation has suggested that treatment with cyclosporine for periods in excess of 12 months causes a progressive native nephropathy often leading to dialysis dependence. The extent of this apparent discrepancy between native kidneys and renal allografts is the subject of this study, which examines the evolution of renal function in 119 kidney and 100 heart transplant recipients receiving 12 or more months of cyclosporine immunosuppressive therapy administered in uniform protocols by affiliated clinical transplantation programs. The evolution of renal function in both study cohorts was analyzed retrospectively on the basis of serial serum creatinine (Crs) determinations. Assessment of group mean Crs, reciprocal Crs (1/Crs), and slopes of the curves obtained by plotting 1/Crs versus time in individual patients revealed a significant decline of native kidney function over the first 6 posttransplant months in the cardiac allograft group. Thereafter, however, native kidney function stabilized in these patients, and the aggregate trend was suggestive of no further decline in function over a 3- to 4-year follow-up period. Kidney transplant recipients had an aggregate trend of slowly declining allograft function consistent with the effects of chronic immunologic injury. The data were not consistent with a uniform pattern of a progressive, cyclosporine-induced loss of renal function in either cohort. Long-term use of cyclosporine was found to be associated with impaired but generally stable aggregate renal function in both the heart and the kidney transplant cohorts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Treating cardiac allograft rejection: present approach--analysis of 100 consecutive patients.

In addition to rejection, complications of rejection prophylaxis and treatment are major causes of mortality and morbidity during the first year after heart transplantation. To decrease complications related to antirejection treatment, our present approach is to assess each rejection episode individually and to adjust treatment accordingly. This article presents the analysis of rejection in the last 100 patients who underwent heart transplantation at our institution.

Antibodies, Monoclonal↗
PubMedDate not supplied

Nutritional assessment of patients with extended left ventricular assist device support.

The nutritional status of nine patients with end-stage heart disease who were supported by a left ventricular assist device (LVAD) for more than 30 days while awaiting cardiac transplantation was evaluated. Nutritional status was indicated by the following scale: 0-2, adequate nourishment; 3-5, moderate malnourishment; greater than 5, severe malnourishment. This scale was based on serial assessments of albumin, transferrin, total lymphocyte count, percentage of ideal body weight, midarm circumference, triceps skinfold, and arm muscle circumference. Each variable was compared with established standards before implantation and before transplantation times and assessed 1 point if less than the normal value and 0 points if within the normal range. At the time of LVAD implantation, 5 patients had a score of 0-2, 3 patients had a score of 3-5, and 1 patient had a score greater than 5. At the time of cardiac transplantation, 7 patients had a score of 0-2, 2 patients had a score of 3-5, and no patients had a score greater than 5. The patients who were able to meet at least 50% of their daily caloric and protein requirements by oral intake alone were noted. At LVAD implantation, only 2 patients (22%) met this requirement; however, 6 patients (67%) met this requirement at the time of cardiac transplantation. All 9 patients underwent cardiac transplantation, and 8 survived. Thus, it appears that extended LVAD support and maintenance of hemodynamic stability allow patients to regain the desire and ability to achieve adequate nutritional status, which may considerably reduce their perioperative transplant risks.

Anthropometry↗
PubMedDate not supplied

Improved survival after Hemopump insertion in patients experiencing postcardiotomy cardiogenic shock during cardiopulmonary bypass.

Immediate placement of a Hemopump (HP) ventricular assist device was undertaken in nine patients (seven men, two women) after other attempts at weaning from cardiopulmonary bypass (CPB) after coronary bypass surgery had failed. All nine patients (100%) were successfully weaned from CPB, and six (63.3%) gradually improved enough to permit removal of HP support. Five (83.3%) of the six who were weaned from CPB survived beyond hospital discharge. HP support was evaluated in terms of vital organ function, incidence of complications, and clinical outcome. In both survivors (S) and nonsurvivors (NS), serial hemodynamic measurements were taken. Although there were few differences in hemodynamic parameters between groups at 4 hr, by 24 hr the S group had markedly improved cardiac index, Glasgow Coma Scale, urinary output, and pulse pressure and required far less inotropic support than did the NS group. All four patients who required high dose inotropic agents to maintain acceptable end-organ perfusion on HP support died; three were unable to tolerate weaning from the HP, and all died within 72 hr of surgery because of ineffective myocardial recovery. None of the survivors required additional early inotropic augmentation. Renal perfusion appeared to be well maintained, even with mean arterial pressures below 60 mmHg during HP support. There were no episodes of hemolysis, infection, or limb ischemia in either group. Thus, the Hemopump provided excellent circulatory support for those patients who could not be weaned from CPB by traditional methods.

Cardiopulmonary Bypass↗
PubMedDate not supplied

Clinical experience with Muromonab-CD3 monoclonal antibody (OKT3) in heart transplantation.

Muromonab-CD3 (Orthoclone OKT3) monoclonal antibody was used as immunosuppressive therapy in 24 selected, cyclosporine-treated heart transplant recipients. Patients included 15 men, eight women, and one child. Mean age was 47 years. Eight patients (group 1) received OKT3 as rescue therapy for rejection, eight (group 2) as primary therapy for rejection, and eight (group 3) as induction therapy. Drug efficacy in the reversal or prevention of rejection in group 1 was 71%; in groups 2 and 3 it was 100%. Recurrent rejection occurred in three of 20 (15%) patients, despite optimal cyclosporine maintenance therapy after OKT3 therapy. Two patients were re-treated successfully for rejection with second courses of OKT3. Systemic side effects occurred in all patients, but in no case did they necessitate cessation of therapy. Infectious complications occurred in all except one patient, typically within the first month after therapy. On the basis of this experience, OKT3 therapy appears highly effective in reversing and preventing cardiac allograft rejection. Further research of the potential complications of such therapy is required to establish optimal dosing schedules and indications for its use after heart transplantation.

Antibodies, Monoclonal↗
PubMedDate not supplied

Heterotopic heart transplantation: a reliable option for a select group of high-risk patients.

From July 1982 through February 1988, 229 patients underwent heart transplantations at the Texas Heart Institute, Houston, 11 of whom had heterotopic transplantations. Indications for the heterotopic procedure included pulmonary hypertension (eight patients) and marked body-weight mismatch (greater than or equal to 20%) between the recipient and donor (three patients). The 1-year actuarial survival rate for the heterotopic group is 80.4% compared with 77.9% for the orthotopic group. Despite similar immunosuppressive regimens, the incidence of advanced rejection within 60 days after transplantation was 9.1% (one of 11 patients) for the heterotopic patients and 33.7% (68 of 202 patients) for the orthotopic group. The one heterotopic patient who experienced rejection in this period had a positive retrospective lymphocyte crossmatch. Seven patients who had heterotopic heart transplantations had right pleural effusions; three of these required tube thoracotomy. Two others experienced angina of the native heart, but the symptoms abated with cessation of native heart function. Despite anticoagulant therapy, one patient had reversible neurologic events caused by emboli. Some of the patients had pulmonary and embolic complications, but all of these problems were readily manageable and resolved without permanent sequelae. In orthotopic transplantation, the presence of pulmonary hypertension can compromise donor heart function in the intraoperative or immediate postoperative periods. Patients with this problem, previously considered unsuitable candidates for transplantation, may have a successful transplantation with the heterotopic technique. Although heterotopic heart transplantation is technically more demanding and may be associated with complications that do not occur in orthotopic transplantation, our experience has shown that it is a reliable surgical option for these high-risk patients.

Adult↗
PubMedDate not supplied

Treatment of moderate heart allograft rejection with cyclosporine.

In the management of heart transplant patients, treatment of acute rejection, as diagnosed by means of endomyocardial biopsy, is critical. Standard antirejection agents include corticosteroids, antithymocyte globulin, and orthoclone. In addition to these drugs, we used increased dosages of cyclosporine to treat 27 episodes of moderate allograft rejection in 24 patients. To qualify for inclusion in this study, patients could not show signs of cyclosporine toxicity despite normal (200 to 300 ng/ml) or high cyclosporine levels and clinical signs of rejection. Therapy consisted of increased oral dosages of up to 14 mg/kg/day of cyclosporine in addition to 1 to 3 mg/kg/day of intravenous cyclosporine. In all 24 patients high levels of cyclosporine were maintained until signs of toxicity appeared, at which point the dosage was adjusted. If endomyocardial biopsy indicated improvement, the dosage was readjusted to maintain cyclosporine levels between 200 and 300 ng/ml. Treatment was successful in 22 cases (81.5%). We compared this group of patients with a not randomly selected but time-overlapping group of 32 patients, who received a steroid pulse for moderate allograft rejection. The incidence of infectious episodes was significantly lower in the cyclosporine-treated patients than in patients given a steroid pulse. There were no signs of permanent kidney or liver damage during or after treatment with increased dosages of cyclosporine. Therefore we conclude that increased dosages of cyclosporine are safe and effective in treating moderate allograft rejection.

Adult↗
PubMedDate not supplied

Evaluation of chronic renal disease in heart transplant recipients: importance of pretransplantation native kidney histologic evaluation.

Although long-term use of cyclosporine has been implicated in the pathogenesis of arteriolar hyalinosis, interstitial fibrosis, and glomerulosclerosis observed in the native kidneys of heart transplant recipients, it is not clear that these histologic abnormalities are entirely specific for a drug-induced toxic nephropathy. The purpose of this study was to determine whether long-standing congestive heart failure, particularly when complicated by disease processes such as atherosclerosis and hypertension, may independently predispose to the development of similar renal histopathology. Records and specimens were selected from autopsy files for evaluation of clinical profiles and kidney histology in 16 patients who died of end-stage cardiomyopathy of varying causes without having recourse to heart transplantation. The study cohort consisted of 12 men and four women. Cardiomyopathies were the result of coronary artery disease in six patients and nonischemic causes in the other 10 patients. The mean age at the time of death was 53 +/- 3 years (range 28 to 74 years). Thirteen (81%) of 16 patients had a history of hypertension. Nadir serum creatinine concentrations during the month before death were 1.7 +/- 0.2 mg/dl (range 1.2 to 3.5 mg/dl). Interstitial fibrosis, tubular atrophy, and glomerulosclerosis were present in 15 (94%) of 16 patients. Arteriosclerosis and arteriolosclerosis were found in 13 (81%) of 16 and 14 (88%) of 16 patients, respectively. A nodular pattern of arteriolar hyalinosis was observed in two patients with ischemic disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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Flail tricuspid leaflet after multiple biopsies following orthotopic heart transplantation: echocardiographic and hemodynamic correlation.

Flail tricuspid leaflet has been reported as a relatively uncommon complication of endomyocardial biopsy in orthotopic heart transplant recipients. However, the relationship of this complication to the number of biopsies performed and to the site of access for biopsy is not known. The objectives of this study were to assess the prevalence of flail tricuspid leaflet/torn chordae tendineae in our recent transplant population, define the relationship of this complication to endomyocardial biopsy, and to correlate echocardiographic assessments of tricuspid regurgitation severity with hemodynamic data obtained at cardiac catheterization. From January 1991 to March 1993, 181 patients who had undergone orthotopic heart transplantation at our institution were evaluated with echocardiography for the presence of a flail leaflet or torn chordae tendineae of the tricuspid valve and tricuspid regurgitation. After identifying this complication in patients, we reviewed their hemodynamic tracings and biopsy protocols from the catheterization laboratory. The hemodynamic tracing chosen was that which was done at the time the flail leaflet was first diagnosed. Of the 181 patients, 21 (11.6%) had flail leaflet or torn chordae tendineae of the tricuspid valve. The group comprised 18 male and 3 female patients. The mean duration from the time of transplantation was 42 months (range, 1 to 87 months). The mean number of biopsies performed per patient was 15.5 (range, 2 to 27). The mean severity of tricuspid regurgitation by echocardiography was grade 3 (moderate); seven patients (33%) had severe regurgitation. The mean right atrial v wave by catheterization was 15 mm Hg (range, 6 to 26 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Function, Right↗