A preliminary experiment on arterial occlusion using radiofrequency energy was performed. A surgitron FFPF was used as a radiofrequency power generator, and a Tracker 18 catheter was used as a probe insulator. A 10 mm length of the guide wire protruding from the tip of catheter was used as the radiofrequency probe. To examine the safety of this procedure within the vessels, the following experiments were performed. A 2.5 mm diameter dimple at the surface of a sausage was filled with human blood. We inserted various lengths of non-insulated guide wire into the dimple and supplied radiofrequency power. We then measured the time until air bubbles appeared in the dimple. With a 10 mm length of non-insulated guide wire, this took over 30 sec. Animal experiments were carried out in 17 canine arteries. The diameter of these arteries ranged from 1.3 to 3.7 mm. Before the procedure, angiograms were taken using a 5 F catheter from the right femoral artery. A tracker 18 catheter and guide wire were inserted to the target position co-axially. The guide wire was attached to the radiofrequency generator. The tip of the guide wire functioned as the convergence point of an electrically conducting induced current. Treatment was performed by supplying radiofrequency power of various durations.(ABSTRACT TRUNCATED AT 250 WORDS)