Die Mikrodiagonalpumpe : tierexperimentelle Untersuchung eines Linksherzunterstützungssystems unter besonderer Berücksichtigung des Thromboembolie-Risikos

Due to the discrepancy between the number of available donor organs and patients waiting for heart transplantation after suffering from end stage heart failure, intensive research has been undertaken to find alternatives to bridge time to transplantation or as live saving therapy. Over the last years a couple of pulsatile and non-pulsatile assist devices have been developed, aiming to improve the current situation. Despite the continuous enhancement of these assist devices they still are affiliated with a considerable amount of complications. Amongst others, bleeding and thromboembolic complications occur, which adversely affect the outcome of patients. The aim of this study was therefore to evaluate a new left ventricular assist device, developed from the Institute of Biomedical Science in Aachen, in an animal study. This “microdiagonal blood pump” is a non pulsatile device, which is suitable for an intrathoracic implantation. In this approach the microdiagonal pump was implanted in 6 calves with a body weight between 80-90 kg. For that purpose, a left-sided thoracotomy was carried out and the inflow conduit was anastomosed with the left atrium. The outflow conduit was anastomosed with the decending aorta, the device was adjusted to a flow of 2-3 l/min and placed at the phrenicocostal recessus. The test period extended for 7 days in which device data was continuously recorded and blood samples where taken several times a day. In this regard hemoglobin, hematocrit, platelet count, free plasma-hemoglobin, coagulation tests, electrolytes und renal function were determined. Analysis of these parameters revealed no signs for significant hemolysis. Hemoglobin, hematocrit and platelet count decreased postoperative due to intraoperative blood loss, but attained almost normal levels at the end of the test period, which is in accordance with a low deterioration of blood cells by the device. Coagulation tests changed due to anticoagulation therapy with heparin in the designated areas and can therefore be interpreted as an effective anticoagulation. At the end of the test period the animals were sacrificed and a thorough autopsy was carried out. Following the macroscopic analysis, histologic examination of brain, liver, kidney, lung and heart were performed. Examination revealed no signs of infarction or ischemia in all brains. The livers of all animals showed no pathologic changes as well. All hearts showed a pericarditis due to operative reasons. In the evaluation of the lungs a pleuritis as well as atelectasis could be observed, caused by intrathoracic placement of the device and operative trauma. In the kidneys some areas with infarction were found, probably caused by arterial embolisation. Origin of the emboli probably has been the interface between socked and case as well as the top of the impeller of the microdiagonal pump. Embolisation to the kidneys is probably due to anastomosis with the descending aorta and the high specific blood flow of the kidneys. Reasons for thromboembolic events were likely due to a flow deceleration or change of flow characteristics at the top of the impeller. Also a material inhomogenity at the pump interface could account for this effect. These entrapments are currently under revision and will be tested in a redesign of the microdiagonal pump soon. In summary the micrdiagonal pump seems to be a promising left ventricular assisting device. After redesign, the microdiagonal pump might be a device having good chances of success due to its size and capability. However before clinical application these results need to be validated by long term assist with this device.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2008

Author dc:creator

• Hoburg, Arnd Thomas

Contributors dc:contributor

• Autschbach, Rüdiger

• info:eu-repo/classification/ddc/610
• Herzinsuffizienz
• Herzersatz
• Herzdekompensation
• Herzchirurgie
• Blutpumpe
• Medizin
• Linksherzunterstützung
• Diagonalpumpe
• left ventricular assist device
• microdiagonal blood pump
• animal model

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-112736%22

OAI record oai:identifier

https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A50181