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Biomedical subjects

V Bors

Publications and source records attributed to V Bors.

At least 91 records · Page 5Linked to original sources
PubMed1989

Orthotopic transplantation after implantation of a Jarvik 7 total artificial heart.

A total artificial heart was used to support the circulation in 33 heart transplantation candidates who were expected to die before procurement of a donor heart. Twelve of these patients (mean age 35 +/- 10 years) underwent cardiac transplantation. Another patient is still being supported with the total artificial heart 90 days after implantation. The other 20 patients died during mechanical support because their condition could not be stabilized for transplantation, despite blood flow restoration. Fifty-six percent of the patients younger than 40 years underwent successful transplantation and six of nine patients are long-term survivors. By comparison, in the older group, 17.6% of patients underwent transplantation and one of three survived long term. Forty-four percent of patients in the acute decompensation group had successful transplantation and four of seven patients are long-term survivors. In the chronic decompensation group these figures were 29.4% and three of five patients. All patients who were heavily immunosuppressed (n = 4) died of sepsis. Transplantation was considered and performed only when the patient's condition was correct and stable. In six patients an infection developed in the immediate posttransplant period. Three of the infections were resolved with antibiotic therapy. One originated in the mediastinum and is still unresolved, although the patient's condition is improving. Another patient died of an anoxic coma caused by ventilatory problems. There were two late deaths at 14 and 19 months, one resulting from a combination of toxoplasmosis and rejection and the other from a Kaposi sarcoma caused by azathioprine treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Hemodynamic characteristics of the Jarvik-7 total artificial heart.

To identify the optimal means of artificial circulation, driving controls and resultant hemodynamics were correlated with clinical outcomes in 37 Jarvik-7 recipients up to 72 hours after implantation. When patients with subsequent transplantation (n = 16) were compared with those who died on the Jarvik-7 heart (n = 21), there were no significant differences in total artificial heart driving mode such as frequency, ventricular driving pressures, systolic-diastolic ratio, or vacuum use, nor were there any differences in the hemodynamics achieved, such as device output (cardiac output) or atrial filling pressures, throughout the observation. However, improvements of other organ functions, especially kidney and liver, were remarkable in that transplant patients immediately experienced increased urine output and reversal of secondary organ dysfunction. The nontransplant group failed to diurese and continued to deteriorate despite similar hemodynamics. When a smaller model of the Jarvik-7 (volume of 70 ml, n = 18) was compared with the standard model (volume of 100 ml, n = 19), again there were no significant differences except that ventricular stroke volume was consistently less for the 70-ml model. Because of a slightly higher heart rate in the smaller model, device output did not differ between recipients of the two types. The results suggest that once successfully implanted, the Jarvik-7 provides adequate perfusion without associated mortality from circulatory failure, regardless of the size of the ventricle. Recovery from other organ failure appears to be independent of postimplant hemodynamics, a phenomenon that suggests the importance of preimplant status and patient selection.

Adult↗
PubMed1989

Cardiac transplant recipients with preoperative pulmonary hypertension. Evolution of pulmonary hemodynamics and surgical options.

Among 48 consecutive patients with pretransplant pulmonary vascular resistance (PVR) greater than 4 Wood units, 38 patients underwent orthotopic heart replacement (OHT), and the remaining 10 received a graft in a heterotopic position (HHT). The OHT recipients were smaller (63 vs. 73 kg, p less than 0.05) and received a larger donor heart (donor-recipient, 109% vs. 79%, p less than 0.001) with a shorter graft ischemic time (108 vs. 139 minutes, p less than 0.05) than HHT recipients, reflecting patient selection and surgical complexity. Comparison between the hospital survivors and nonsurvivors identified the selection of HHT and graft ischemic time in excess of 150 minutes as potent risk factors. Immediately after transplantation, pulmonary artery (PA) pressures dropped to almost one half of preoperative values regardless of the mode of transplantation. Within the next 24 hours, however, the OHT group required lower doses of inotropes, had lower left atrial pressure (12 vs. 16 mm Hg, p less than 0.05), and were more frequently extubated (58% vs. 10%, p less than 0.01). Catheterization at 10 days revealed a doubled cardiac index and a dramatic reduction in PVR for both groups. The higher the preoperative PVR value, the more substantial the reduction observed, resulting in normalization of PVR for all survivors. The incidence of early graft failure was similar between the groups, but HHT recipients frequently developed pulmonary complications and infection, resulting in a 30% hospital survival in contrast to 71% in OHT recipients (p less than 0.05). The results suggest that transplant candidates with pulmonary hypertension might better be treated by OHT with an oversized, on-site, viable donor heart than by HHT.

Adult↗
PubMed1989

Factors affecting survival after heterotopic heart transplantation.

In an attempt to identify the factors that influence survival after heterotopic heart transplantation, 42 consecutive recipients of heterotopic heart transplant were reviewed. Preoperative pulmonary artery pressures, pulmonary vascular resistance, and donor age significantly differed between hospital survivors and nonsurvivors. Postoperative survival analysis between pairs of groups of patients divided by each of these variables disclosed a significant difference, which confirmed the effects of these variables on survival. Evolution of pulmonary hemodynamics was compared between patients with preoperative pulmonary artery diastolic pressure greater than 25 mm Hg (pulmonary hypertension; n = 22) or less than 25 mm Hg (nonpulmonary hypertension; n = 20). Despite marked differences in preoperative pulmonary hemodynamics, pulmonary artery pressures were dramatically reduced immediately after transplantation, and pulmonary vascular resistance diminished to upper normal limits at 10 days when there were no longer differences in pulmonary vascular resistance between the two groups. Immediate deaths were related to left ventricular failure, and the incidence was similar between the groups. Despite such normalization of pulmonary hemodynamics, patients with preoperative pulmonary hypertension experienced more frequent ventricular fibrillation, required longer respiratory support, and developed lethal pulmonary or systemic infection, which resulted in a 32% (7/22) hospital survival rate compared with 90% (18/20) in patients without pulmonary hypertension. Despite the dramatic improvement in pulmonary hemodynamics, heterotopic heart failed to demonstrate the expected advantages because of frequent pulmonary complications and infection, which resulted in failure to improve the prognosis of patients with preoperative pulmonary hypertension.

Actuarial Analysis↗
PubMed1988

Doppler echocardiography for the diagnosis of acute cardiac allograft rejection.

To evaluate the changes in left ventricular filling associated with acute cardiac rejection, serial Doppler echocardiographic examinations were prospectively performed on the same day as endomyocardial biopsy in 55 consecutive patients who successfully underwent orthotopic transplantation and were free of a previous episode of rejection. On average, 8.6 Doppler studies per patient were performed within a 6 month period after transplantation. Recordings of mitral flow were made with pulsed Doppler and two-dimensional echocardiography from an apical four chamber view; isovolumic relaxation time, peak early mitral flow velocity and pressure half-time were measured. The patients were classified into two groups on the basis of the histopathologic findings: group I (25 patients with at least one episode of mild or moderate rejection) and group II (30 patients without rejection). In group I, rejection was associated with a significant decrease of isovolumic relaxation time (p less than 0.005) and especially pressure half-time (p less than 0.0005) with no change in heart rate and peak early mitral flow velocity. In group II, Doppler indexes remained unchanged. These changes were not associated with alterations in left ventricular systolic function assessed by echocardiography. Isovolumic relaxation time and pressure half-time both returned to values similar to baseline values after immunosuppressive therapy (p less than 0.05 and p less than 0.0005, respectively). With 20% decrease in pressure half-time as a criterion for acute rejection, sensitivity was 88%, specificity 87% and positive predictive value 85%. Thus, Doppler echocardiographic evaluation of left ventricular diastolic function provides an excellent tool for early detection of acute rejection and noninvasive monitoring of the cardiac transplant recipient.

Adolescent↗
PubMed1988

Clinical application and patient selection in the use of a total artificial heart as a bridge for transplantation.

Between April 1986 and July 1987, 21 patients underwent orthotopic implantation of a total artificial heart (Jarvik 7) at La Pitié Hospital. There were 18 men and 3 women with a mean age of 37.3 +/- 11.4 years. The device implanted was the 70 ml version in 10 patients and the 100 ml version in 11 patients. In the results, three variables were analysed: age, acute myocardial decompensation or chronic myocardial failure, and aetiology of the 21 patients treated. 10 (47.6%) had adequate support and were successfully transplanted. Eleven patients (52.4%) died during circulatory support. The main causes of death were sepsis and multiple organ failure. In only one patient was a mismatch between the heart and chest cavity present. There was no clinical evidence of thromboembolic complications. Patients of 40 years of age and less have an 80% chance of being successfully transplanted in comparison with a 25% success rate in older patients. Patients that developed sudden cardiac decompensation have a 75% success rate for transplantation in comparison with 44.4% success rate in patients with a chronic illness. Early implantation of the device, before the development of irreversible damage in other organs, is recommended in younger patients with acute or chronic disease and in older patients with acute myocardial failure. The use of this device is contraindicated in immunosuppressed patients due to the high risk of infection.

Adult↗
PubMed1988

Calcified aortic stenosis: operative risk.

Surgery of the aortic valve due to calcified aortic stenosis has been a well known procedure for many years. Continuous clinical improvement after isolated aortic valve replacement can be documented in the majority of patients followed up for several years. Surgery of this type in association with other procedures (coronary artery bypass, mitral valve replacement, etc.) has become more and more common. For this reason we have analysed the operative risk of a group of patients with calcified aortic stenosis that were operated on at La Pitié Hospital from 1980 to 1984.

Age Factors↗
PubMed1988

Mid-term results of the Liotta-Bioimplant low profile bioprostheses.

Low profile bioprostheses are particularly useful for certain anatomical conditions. In some patients with rheumatic aortic insufficiency, an important dilatation of the aortic annulus is present, even when the subcoronary aorta is not enlarged. In these cases, the bioimplant heart valve with its low height avoids any threat to the aortic wall or to the coronary ostia. Frequently, the left ventricular cavity is not enlarged in patients with mitral stenosis. The characteristic low profile of this valve avoids left outflow obstruction as well as traumatism of the left ventricular wall. In the tricuspid position, this design is particularly useful because it leaves the right ventricular cavity totally free. From February 1981 to December 1983, 198 bioimplant (LIOTTA) low profile bioprostheses were implanted in 184 patients. There were 63 aortic (AVR), 101 mitral (MVR), 14 mitral and aortic (MAVR), and 6 tricuspid (TVR) valve replacements. Early mortality (30 days) was 6% (AVR = 1.6%; MVR = 8.9%; MAVR = 7.1%; TVR = 0). The 181 survivors were followed over a period of 3-84 months (643 patient-years). The thromboembolic complication rate was low (0.7%/patient-year) and 96.9% +/- 1.4% of patients were free of thromboembolism (AVR = 98.2% +/- 1.7%; MVR = 97.6% +/- 1.7%). Five years after implant, 91.7% +/- 3.2% of patients were free of valve failure (AVR = 93.7% +/- 4.4%; MVR = 88.8% +/- 5.2%). Actuarial analysis shows an expected survival at 5 years (average) of 87.2% +/- 3.4% (AVR = 87.4% +/- 6%; MVR = 87.3% +/- 4%) with an actuarial rate of freedom from reoperation of 87.5% +/- 3.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Morbidity and mortality seen in patients with a Hancock bioprosthesis, followed for more than 5 years. Experience at the La Pitié Hospital].

Between 1975 and 1983, 305 Hancock bioprostheses were implanted at the La Pitié Hospital, Paris, including 133 on the aortic valve and 172 on the mitral valve. The operative mortality rate was 6 p. 100 in patients with isolated aortic valve replacement and 12.8 p. 100 in patients with isolated mitral valve replacement (including 4 reoperations for mechanical valve thrombosis). 245 patients were followed up for a mean period of 5 1/2 years. The actuarial survival rate, operative mortality excluded, was 77.5 +/- 4.4 p. 100 in the aortic valve group and 76 +/- 4.4 p. 100 in the mitral valve group (non significant difference). Later after surgery, 8 embolic accidents (5 in the mitral valve group, 3 in the aortic valve group) occurred, and 20 patients developed endocarditis. Forty-nine patients required reoperation, 33 of them for deterioration of the bioprosthesis. The probability of being free from such deterioration varied significantly according to the patient's age at the time of the operation. In the aortic valve group this probability at 8 years was 97 p. 100 +/- 2.7 p. 100 for patients over 35 and 63.3 p. 100 +/- 1.7 p. 100 for patients under 35; the corresponding figures at 8 years in the mitral valve group were 80 p. 100 +/- 3.8 p. 100 for patients over 35 and 55.2 p. 100 +/- 2.2 p. 100 for patients under 35. There was no significant difference between the mitral and the aortic valve groups with regard to the percentage of prosthetic valve deterioration. The operative mortality rate in reoperations was 14.2 p. 100 irrespective of the cause of death.

Adult↗
PubMed1988

[Heart-lung transplantation].

In this study the transplantation group of La Pitié Hospital, Paris, review heart-lung transplantation on the basis of data from the literature and of their own experience. Successively, the history, indications, pre-operative evaluation, donor selection, operative procedure with its immediate, mid-term and late complications, as well as treatment and post-operative follow-up are described.

Heart Transplantation↗