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H Mückter

Publications and source records attributed to H Mückter.

41 records · Page 3Linked to original sources
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A tricuspid polyurethane heart valve as an alternative to mechanical prostheses or bioprostheses.

The main disadvantages of today's heart valve prostheses are the need for lifelong anticoagulation for mechanical valves and problems with biodegradation for tissue valves. Therefore, a new valve type devoid of these problems would be a major step forward. In order to evaluate a new valve design made by dipmolding with different PU materials, an animal test series was carried out in which two valves from each material were implanted into the mitral position of growing Jersey calves. The surgical procedure and postoperative catheterization data are presented. The survival times ranged between 127 and 291 days. Organs and explanted valves were examined post mortem according to general pathology standards. Specifically, the valves were histologically examined for calcium deposits and investigated by light microscopy, REM and EDAX. All explanted valves showed calcification and immobilization, but the results suggest that at least two PU materials attain survival times which are far beyond the lifetime of bioprostheses under the same implant conditions, justifying further in vivo studies in adult animals.

Animals↗
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Counterpulsation in atrio-aortic bypass: theoretical and experimental aspects.

Mechanical support of the heart is becoming an established method for emergency situations or bridge to transplant applications. Nevertheless the discussion concerning the importance of co- or counterpulsation isn't yet finished. Using a theoretical model of the cardiovascular system, the influence of a LVAD triggered to co- and counterpulsation will be discussed. The theoretically obtained results are compared to a series of six experiments in calves, where the influence of LVAD-pumping in co- and counterpulsation pumping mode was investigated. Additional benefits were seen compared to the copulsation pump method: there was more reduction of the cardiac stroke work, afterload and an increase of the diastolic pressure, which is important for the coronary blood flow. In order to verify the benefits of the additional reduction of pressure work a small series of animal experiments was performed.

Animals↗