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Biomedical subjects

A Bernhard

Publications and source records attributed to A Bernhard.

At least 19 recordsLinked to original sources
PubMed1992

Psychosocial, neuropsychological and neurological status in a sample of heart transplant recipients.

The sample for this psychosocial follow-up study was formed using the 71 surviving patients from a total of 100 who underwent heart transplantation up until March 1990 at Kiel University Hospital. Forty of these could be investigated comprehensively. The neurological investigation comprised EEG and auditory and visually evoked potentials. The psychological investigation started with several neuropsychological tests; additionally all patients were interviewed and they completed questionnaires concerning anxiety, depression, ways of coping, personality characteristics and life satisfaction. Within the entire sample, there were few indications for specific psychological impairment. The psychosocial status of the patients was not significantly related to the time which had elapsed since they underwent transplantation. There were few associations between neuropsychological and psychosocial data, and several indicators of early postoperative complications which are described in the literature (e.g., length of stay in the intensive care unit). Clinically relevant subgroups (formed on the basis of neuropsychological test results, anxiety and depression) did not differ in terms of these indicators. Nevertheless, a considerable proportion of the patients (25%) were characterized by having a higher level of affective and neuropsychological impairment. Although based upon retrospective investigations, the results of this follow-up generally correlate with those gained from Anglo-American countries. In interpreting the results one needs to consider the possible influence of premorbid personality characteristics as well as denial which may be typical for patients undergoing heart transplantation.

Adaptation, Psychological↗
PubMed1992

Truncus arteriosus communis associated with interrupted aortic arch: a report on two uncommon cases.

The paper presents two infants with the A-4 type of truncus arteriosus communis (according to Van Praagh's classification). One patient who survived a surgical procedure demonstrated a rare variant of aortic arch interruption to the left off the left subclavian artery (type A according to Celoria and Patton), whereas the second presented an uncommon anomaly in which the right subclavian artery originated from the descending aorta with associated severe truncal valve incompetency. The authors describe the clinical picture along with the surgical treatment of the first infant who being six days old was subjected to a correction employing the wide patent ductus arteriosus to reconstruct the aortic arch, following the method described by Gomes and McGoon. Subsequently an aortic homograft was implanted in order to connect the right ventricle and the pulmonary artery.

Aortic Arch Syndromes↗
PubMed1992

Circumferential rupture of the ascending aorta in a fusiform aneurysm.

A case of complete circumferential rupture of the ascending aorta with massive hemorrhage into the pericardial space and around the aortic arch is described. Computed tomography was used to establish the diagnosis. Rupture occurred distal to the origin of the coronary arteries without impairment of aortic valve function, and therefore a preclotted woven Dacron graft was inserted. To the best of our knowledge, this is the first documented case of complete rupture of the ascending aorta in a fusiform aneurysm and the first report of its successful surgical treatment.

Aortic Aneurysm↗
PubMed1992

Performance of a stentless xenograft aortic bioprosthesis up to four years after implantation.

Conventional biologic and mechanical prostheses have important limitations with regard to their hemodynamic characteristics and long-term durability. We evaluated the hemodynamic function of a stentless porcine aortic prosthesis in 10 patients by invasive pressure measurements and angiography with videodensitometry 8 +/- 4 days after operation, as well as by Doppler echocardiography 35 +/- 15 months after valve replacement. The early postoperative invasive study revealed a mean gradient of 8 +/- 6 mm Hg across the prosthesis, no regurgitation in eight patients, and mild regurgitation, defined as less than 20% regurgitant fraction, in the remaining two patients. The late postoperative Doppler echocardiographic study revealed a mean gradient across the aortic prosthesis of 6 +/- 3 mm Hg, mean Doppler-derived valve orifice area of 1.8 +/- 0.6 cm2, and color Doppler flow velocity mapping suggested no regurgitation in eight patients and mild regurgitation in two patients corresponding to early postoperative angiography. None of the 10 patients received anticoagulation therapy. The clinical course of all patients was without incident. This stentless aortic bioprosthesis may offer hemodynamic advantage; however, further studies are needed to allow comparison with conventional mechanical and biologic prostheses.

Adult↗
PubMed1991

An alternative technique for orthotopic cardiac transplantation, with preservation of the normal anatomy of the right atrium.

The standard technique for orthotopic cardiac transplantation implies large atrial anastomoses which do not preserve the anatomical integrity of the donor atria. This may become a potential source of electrophysiological and mechanical atrial dysfunction, especially in the right atrium with the sinus node and the sensitive low-pressure atrioventricular valve. As an improvement we suggest an alternative technique which we have recently developed for orthotopic cardiac transplantation; it combines the simple, convenient left atrial connection of the standard technique with individual anastomoses of the superior and inferior venae cavae, preserving the right atrium of the donated heart intact. This technique and our first results in two cases are described. Postoperatively, no arrhythmias and no signs of tricuspid insufficiency were observed.

Adult↗
PubMed1991

PTFE sutures for mitral valve reconstruction--histological findings in man.

A case of mitral valve reconstruction with replacement of the chordae tendineae by polytetrafluoroethylene (PTFE) sutures is described in a 52-year-old man. 21 days after operation mitral valve insufficiency due to rupture of a natural chorda led to reoperation with mitral valve replacement. The cardiac valve tissue was examined both macroscopically and microscopically. It showed a proliferation of fibroblasts. However, there was no endothelial cell layer detectable. To the best of our knowledge our case is the first report of the histological changes in human cardiac valvular tissue after implantation of PTFE sutures.

Chordae Tendineae↗
PubMed1991

Unstented and partial stented bioprostheses for aortic valve replacement--up to 6 years of follow-up.

Since January 8, 1985, three different designs of unstented (type A, n = 9) and partial stented (type B, n = 4; and type C, n = 3) glutaraldehyde preserved porcine aortic valves were used for aortic valve replacement in 16 patients with acquired aortic valve lesions. Type A and type B prostheses were implanted using a two suture row technique. In type C prostheses, only a single suture row was necessary for implantation, facilitating surgery considerably. In all patients, the fully flexible commissures of the bioprostheses were secured to the aortic wall of the recipient. There was no hospital mortality. Two patients with type A bioprostheses died due to noncardiac causes, 4 and 24 months postoperatively. One bioprosthesis in this group had to be replaced after 3 months because of insufficiency. Serial Doppler echocardiographic studies were performed up to 6 years after implantation. No significant leaflet calcification was observed. In three type A bioprostheses, a mild insufficiency without progression was recorded. The latest mean/peak transprosthetic pressure gradients were: type A: 6 +/- 4 mmHg/12 +/- 6 mmHg; type B: 6 +/- 3 mmHg/14 +/- 5 mmHg; and type C: 11 +/- 5 mmHg/18 +/- 8 mmHg. The functional results of the type A and type B bioprostheses have proven to be satisfactory. The slightly higher pressure gradients in patients with a type C bioprosthesis give rise to further refinements of its design. These results confirm the usefulness of imitating normal anatomy by using unstented or partial stented bioprostheses.

Adult↗
PubMed1990

Improved mitral valve replacement.

We describe a simple, reproducible technique of achieving more normal left ventricular function after mitral valve replacement. Polytetrafluoroethylene (PTFE) sutures are used as chordae tendineae to restore the integrity between the mechanical valve and papillary muscles and thus the left ventricular wall.

Chordae Tendineae↗
PubMed1990

Scanning electron microscopy evaluation of the Abiomed 5000 ventricular support system after clinical biventricular assistance.

Twenty-nine days after implantation of an Abiomed 5000 biventricular support system for otherwise intractable end-stage cardiomyopathy, the inner surfaces of the device were examined by means of scanning electron microscopy (SEM). SEM showed clean surfaces inside the blood sacs, with only rare fibrin deposits. There were platelet adhesions on the ventricular side of the artificial atrioventricular valves; no deposits were on the opposite side. Structural deterioration of the closing edge of the artificial valves could be seen. The tubing system was likewise covered by a uniform deposition of single platelets with no major thrombus formation. Postmortem examination of the patient, on the other hand, revealed gross thrombus formation inside both atria at the cannulation sites, despite efficient anticoagulation. We conclude that the Abiomed 5000 per se is unlikely to be the site of major thrombus formation leading to subsequent embolization after 660 h implantation. However, the structural integrity of the adapting areas of the leaflets may become a point of concern. Further research is necessary to improve the atrial cannulation technique in order to prevent the atrial thrombus formation demonstrated as the source of systemic embolization.

Blood Platelets↗
PubMed1989

Assessment of different preservation and storage conditions on aortic valves: introduction of a quantitative measuring method of the integrity of endothelial cells.

The fate of human allogeneic aortic valves depends mainly on their histological and immunological condition at the time of transplantation. A screening test making novel use of Alcian Blue was used to determine the integrity of endothelial cells as a prerequisite to their function. The dye uptake into the nucleus was measured quantitatively. The test was used to compare the effect of different storage mediums and temperatures (+4 degrees C, -30 degrees C, -80 degrees C, DMSO, FCS, RPMI, antibiotic solution) on aortic valves of rats. The cell integrity decreased with increasing storage time and higher storage temperature. The cryoprotective agent DMSO had no essential effect on the maintenance of cell integrity.

Alcian Blue↗
PubMed1989

A "semi-supported" porcine xenograft--description and first clinical use.

The anatomy of valsalva's sinus is such that it decreases the mechanical stress on the leaflets of the aortic valve. Artificial stents impair the hemodynamic performance of an aortic bioprosthesis and lead to unphysiological functional stresses and may also shorten their durability. Therefore a semi-supported xenograft was developed which can be attached with an one-suture row in subcoronary position. This facilitates surgery considerably. Moreover, the commissures can be attached directly to the patient's aortic wall. The semi-supported valve was successfully implanted in a 69 years old patient with a combined aortic valve lesion. Postoperative invasive investigations, including angiography and videodensitometry, showed a normal performance of the valve and a normal anatomy of the aortic root.

Aged↗