MICROPERFUSION PUMP-SYSTEMS AND DEVELOPMENT

Transluminal coronary angioplasty has become an established form of tr eatment for coronary artery disease. The dilatation time is normally r estricted by the ischaemic tolerance. Until today passive perfusion ca theters have been used to maintain coronary blood flow to the distal s egment. However, such continuous perfusion has often been insufficient to retain myocardial function. Active perfusion catheters, instead, h ave not been introduced so far for technical reasons. Active coronary perfusion via dilatation catheters with an intracorporal rotary microp ump was the objective of investigations by Fraunhofer-IPA and the Univ ersity of Essen. The result of the development activities was an inter nal geared pump with an outer diameter of 2.5 mm. Several design studi es were undertaken to integrate the micropump in a PTCA catheter. The most important aspect of the integrated micropump is that the dilatati on time can be prolonged. First in vitro tests with whole-blood showed acceptable mechanical haemolysis of the pump system. Further in vitro tests will lead to an optimized pump design with low mechanical haemo lysis and a high flow rate.