Thermal angioplasty is a newly developed technique that employs a heated metallic tip to thermally ablate atherosclerotic plaques for recanalization of obstructed peripheral arterial blood vessels. However, the current Laser Thermal Probe employs a high power continuous argon laser which is large in size and high in cost. Last year, we developed an electrically heated thermal tip catheter as a possible alternative to the laser probe, and preliminary testing of this device in an in vivo animal model appears promising. Another economical method of heating a metallic tip is to harvest the chemical energy from the combustion of hydrogen gas. This energy can be released and harvested inside a catheter tip in a safe manner by utilizing a palladium sponge catalyst which initiates and maintains the chemical combustion in a controlled fashion. A prototype catalytic thermal tip catheter has been designed and fabricated for in vitro testing. A temperature feed back control device has been added to avoid excessive tissue heating with the aim of minimizing the incidence of vessel wall perforation. Extensive in vivo testing in an atherosclerotic animal model is planned prior to anticipation of clinical human trials.
