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Biomedical subjects

A Bernhard

Publications and source records attributed to A Bernhard.

At least 91 records · Page 5Linked to original sources
PubMed1978

[Hemodynamic and echocardiographic investigations following mitral valve replacement by glutaraldehyde preserved xenografts (author's transl)].

Sequential hemodynamic and echocardiographic studies following mitral valve replacement by glutaraldehyde preserved bioprotheses have been carried out in 40 patients. These investigations have been compared to those of patients having received Björk-Shiley or Lillehei-Kaster valves. Between the two groups the data of heart catheterization showed no differences. Echocardiography however showed an earlier normalisation of the data of the left ventricle after replacement by Hancock valves. Therefore and because of low thromboembolic risc and good mechanical stability and low immunogenecity the use of bioprotheses is recommended.

Aortic Valve↗
PubMed1978

Studies on the antigenicity of vital allogeneic valve leaflet transplants in immunogenetically controlled strain combinations.

The use of defined inbred strains of rats enables reproducible experimentation on the antigenicity of heart valve leaflet transplantation. The inbred strains CAP, F344, and LEW were used as syngeneic, weakly allogeneic (RT-1-identical) and strongly allogeneic (RT-1-incompatible) strain combinations. After heart valve leaflet transplantation, humoral and cell-mediated immune responses were investigated. The results were: (1) Allogeneic heart valve leaflets are antigenic. (2) Just one heart valve leaflet, applied intravascularly induces sensitization of the recipient. (3) In the weakly allogeneic system, sensitization is only revealed by donor-specific skin transplants, while in the strongly allogeneic group, sensitization is demonstrated humorally as well. (4) The greater the immunogenetical difference, the sooner sensitization appears. In the strongly allogeneic system, skin transplants were rejected as "white grafts".

Animals↗
PubMed1977

[Hemodynamics after reconstruction of the outflow tract in tetralogy of Fallot. Infundibulectomy, patchreconstruction or valve rearing conduit (author's transl)].

The peak systolic pressure ratio PRV/PLV of the right and left ventricle after correction of the outflow tract (OFT) in Tetralogy of Fallot (TF) yields reliable dates about the efficiency of the outflowtract correction and the probability of survival. In 110 patients (2 to 57 years) the ratio after correction PRV/PLV was measured and compared with different methods of reconstruction of the OFT. Infundibulectomy (54) pericard-patch insertion across the pulmonary valve ring (43) and a valve bearing Hancock-Conduit (13) were used. To calculate the statistical differences the U-test according to Wilcoxon, Whitney, Mann was applied on the 95% level. Moreover the pulmonary insufficiency (PI) was evaluated in 60 patients within 15 to 60 days, after correction with a videodensitometric method. There is no PI after use of a valve bearing Hancock-Conduit. In severe TF a valve bearing Hancock-Conduit is hemodynamically superior to a pericard-patchreconstruction of OFT to relief right ventricular hypertension, particularly if hypoplasia of pulmonary vessels and pulmonary vascular disease after shunt-operation is present.

Adolescent↗
PubMed1977

[Effect of a preoperative separation of platelets on the postoperative blood loss subsequent to extracorporeal circulation in open heart surgery (author's transl)].

After operations with extracorporeal circulation there is a risk of clotting disorders, due to traumatisation of blood. The extent of cell damage are shown, in particular, by qualitative and quantitative impairment of platelet function. The clinical application of modern blood processors offer the possibility of selecting platelets from patients blood in the immediate preoperative period. Open heart operations were preceded by separation of platelets in 17 patients using a Haemonetics blood processor. After a postoperative retransfusion of the platelets an evident improvement in platelet function and a significant decrease in the predisposition to bleeding was demonstrated in the further postoperative period. During and after extracorporeal circulation the extent of microembolisation was registered by screen filtration pressure. In the clinical experiments, regularly, there is a significant increase of screen filtration pressure in the immediate postoperative period. These reactions were not seen in patients in whom preoperative separation of platelets was carried out. The most important clinical advantage of preoperative plateletpheresis consists in a significant decrease of postoperative blood loss. In particular the development of postperfusion lung will be prevented.

Blood Platelets↗
PubMed1976

[Complications of arterial reconstructions below the knee for chronic vascular occlusion (author's transl)].

From 1967 to 1976 49 reconstructions were undertaken in the area distal of the art. poplitea: 30 femoral-crural bypasses, 12 TEA und 7 orthogradic desobliterations. Complications until clinical demission were reviewed. There were in 8 cases postop. thrombosis which led to 4 amputations. 6 patients suffered from wound infection with one consecutive amputation. 4 hemmorages had to be stopped surgically. THE OVER ALL RATE OF COMPLICATIONS WAS 36,7% WITH A PRIMARY MORTALity of 4%.

Aged↗
PubMed1976

[Clinical experiences with induced preoperative haemodilution in vascular surgery (author's transl)].

A procedure of haemodilution modified for the particular requirements of vascular surgery has been used on 90 hospital patients. 61% of the operations have been performed without using homologous blood. The method applied being clinically well tolerable, it the object of this study to find to what extent a measurable reduction of the loss of blood during the operation with consequently a reduction of the amount of homologous blood administered can be attained. If the tolerable loss of blood is estimated to be 600 ml, in 22% of the cases operated on the administration of homologous blood has been avoided. The improvement in rheology by the infusion of low molecular weight dextran is considered an additional advantage in the special field of vascular surgery.

Aorta↗
PubMed1976

[Metabolism and organ functions in experimental hypothermic, bloodless whole-body perfusion with hydroxyethyl starch (HES)].

After surface-induced hypothermia in 12 cats total body washout was performed followed by 60 min bloodless perfusion. In the rewarming period at 28 degrees C, packed red cells were added and at 35 degrees C, ECC was finished. Functional parameters of metabolism, liver, and kidney were measured and followed by histologic examination. Bloodless perfusion does not alter the morphology of the organs examined. Abnormal values of organ function and metabolic data seem to be reversible.

Animals↗
PubMed1975

The pathological anatomy of surgically reconstructable or prosthetically correctable congenital valvular malformation of the mitral region.

The special pathology of reconstructable or only prosthetically correctable congenital malformations of the mitral valve is described on the basis of the following examples taken from our own operative and autopsy material of the last 5 years: 1. Congenital isolated mitral stenosis in female twins (7 month old infant and 33 month old child). 2. Congenital isolated mitral insufficiency in a 7 1/2 year old boy. 3. Combined mixed mitral valve malformations with a parachute valve-like mitral valve anomaly, combined with hypoplasia of the ascending and descending aortas, in a 6 1/2 year old girl. 4. Congenital mitral insufficiency with a parachute mitral valve, combined with supravalvular aortic stenosis and multiple peripheral stenoses of the pulmonary arteries in a 13 1/4 year old boy. 5. Insufficiency of the mitrally inverted tricuspid valve with so-called corrected transposition of the great vessels in a 6 year old boy and with Ebstein's anomaly in a 2 1/2 year old boy. 6. A second mitral ostium in the aortic mitral leaflet with a partial atrioventricular canal in a 6 3/4 year old girl with Ellis-van Creveld syndrome. 7. Bland-White-Garland syndrome with relative mitral insufficiency in a 5 month old and a 4 month old boy. Despite the recurrence of similar and comparable findings, each of our cases of congenital or early acquired noninfectious mitral valve malformation was formally different. n his was also true for the cases of congenital isolated mitral stenosis in twins. Therefore, surgical correction requires a unique procedure for each case. It is possible to reliably infer the degree of malfunction of the atrioventricular valve in a mitral position from the special pathology only by considering the clinical data. On the other hand, a detailed evaluation of congenital mitral valve malformations is possible only through direct inspection--either by the surgeon or through an autopsy--despite modern cardiodiagnostic methods. Typical secondary findings are also discussed--for instance, endocardial fibrosis of the left atrium and the configuration of the heart. The anatomical prerequisites for surgical reconstruction or replacement of the valve with a prosthesis are mentioned.

Adolescent↗
PubMed1975

[Antibody deficiency states in children].

In more than 2500 immunoelectrophoreses and quantitative immunoglobulin determinations 19 cases of transitory hypogammaglobulinaemia, two cases of sex-linked congenital agammaglobulinaemia, six cases of selective IgA deficiency and nine cases of dysgammaglobulinaemia were diagnosed. In congenital agammaglobulinaemia life-long substitution with gammaglobulin must be instituted. Transitory hypogammaglobulinaemia which occurs mostly at the beginning of the second trimenon usually regresses spontaneously at the age of 15 to 18 months. The increased susceptibility to infections can be overcome by gammaglobulin administration. Dysgammaglobulinaemias with serum concentrations below 400 mg/dl also require gammaglobulin supplements. In IgA deficiency the greatest possible care as regards substitution is indicated because of the danger of severe anaphylactic reactions.

Agammaglobulinemia↗
PubMed1975

[Thrombosis of the Björk-Shiley valve as an early fatal complication of the prothetic aortic valve replacement (author's transl)].

From a series of 28 patients subjected to aortic valve replacement with the Björk-Shiley tilting disc valve prosthesis 3 cases are reported in which massive thrombosis with valve dysfunction and fatal outcome occurred in the very early postoperative period. The autopsy findings and the examination of the blood coagulation state during the first 24 hours postoperatively disclosed in all 3 cases a hypercoagulability being responsible for the massive clot formation. The early recognition and establishment of the diagnosis of a hypercoagulability state and an immediate anticoagulant therapy with heparin are necessary for preventing such early fatal complications in patients with cardiac valve replacement.

Adult↗
PubMed1975

[The influence of increased clotting reactions as shown by thrombosis formation in the immediate postoperative period on aortic valve prothesis (author's transl)].

Massive thrombosis formation on the valve periphery and on the top surface of the valve occurred in three patients (1,5%) in the immediate postoperative period with the Björk-Shiley valve in the aortic position. Between the third and sixth day these patients died of acute heart failure as a result of coronary artery displacement. Upon autopsy operative technical complications and postoperative infections were ruled out as the cause of death. What appears to be clinically important is an increase in clotting time in the immediate postoperative period which can be proven statistically. This increased clotting inclination was only found in these three patients and in one patient with frequent immediate postoperative peripheral embolic episodes. We therefore feel that early anticoagulation therapy is necessary. Heparin administration is preferred as it not only lowers the clotting ability of the blood but also the adhesive quality of the platelets.

Aortic Valve↗
PubMed1975

[Immunglobulin levels and alterations of the lymphocyte function after extracorporal circulation and massive blood transfusion (author's transl)].

Cardiovascular operations are connected with an increased risk of infection. Postoperatively there happened a temporary fall of all immunglobulin levels. Concerning the cellular immunity, we found an impressive decrease of the transformation of the lymphocytes in the presence of polyclonal mitogens which normalises only partially after the eighth day. These results refer to a complex alteration of the immunological apparatus, imposing as a temporary immundeficiency, and could contribute to an elucidation of the increased risk of infections.

Blood Transfusion↗
PubMed1975

[Videodensitometric, angiocardiographic and hemodynamic examinations in corrected tetralogy of fallot].

In 38 children with typical tetralogy of Fallot recatheterization was performed 15 days to 410/12 years after correction. Their age ranged from 47/12 to 181/12 years and their weigh? 14;8 TO 54.4 KG. The biplane angiocardiograms were especially evaluated with respect to thcy to decrease from intraoperative to postoperative values. We did not find a parameter, determined during the operation, which can predict with certainty the operative result, found at the time of recatheterization. The peak pressure ration PRV/PLV seems to be most suitable but in an individual case one cannot rely on it. A diastolic murmur was heart postoperatively in 25 children, 9 of whom had a regurgitation index greater than 10%. In all 38 patients an infundibulectomy was performed, which in every case resulted in a disturbance of the contraction pattern (asynergy) of the right ventricular outflow tract. In the area of the ostium infundibuli small aneurysms were demonstrated in 50% of the cases. They were divided according to their angiographic appearance, the type of asynergy and their visibility on the two standard x-ray projections. In 11 children we observed incompletely resected muscle bundles of the infundibulum. Hemodynamically they were insignificant. Residual muscular infundibular stenoses, causing a pressure gradient, were observed in 8 cases. Aortal indentations of varying degree at the site of cannulation for the extracorporal circulation were present in 91%. In 13 patients an outflow tract reconstruction was necessary. In 8 children the patch was clearly identifiable as such. The necessity of recatheterization after correction of tetralogy of Fallot is discussed.

Adolescent↗