TREATMENT OF REFRACTORY CORONARY OCCLUSIONS WITH A NEW EXCIMER-LASER CATHETER - PRELIMINARY CLINICAL OBSERVATIONS

Background: Total coronary occlusion is a frequent cause of procedural failure after coronary angioplasty, often because of the inability to recanalize the occluded segment with a conventional coronary guidewir e. The novel excimer laser catheter described in this report contains a highly efficient, pulsed excimer laser guidewire designed to create a small channel within the occluded coronary segment. A preliminary re port of the safety and efficacy of this excimer laser catheter is prov ided. Methods: Ten patients with refractory coronary occlusions that c ould not be crossed by experienced operators using conventional guidew ire techniques were treated using a novel laser catheter system. The l aser catheter consisted of a densely packed, multiple fiber, helical g uidewire measuring 0.020 inches (0.51 mm) in diameter, interfacing a 3 08 nm excimer laser system and delivering 70-80 mJ/MM2 of energy to th e output surface. After the laser guidewire had been advanced to the o cclusion site, laser energy was applied to ablate a channel as the wir e was advanced through the occlusion. Once the occlusion had been reca nalized, standard concentric laser or balloon angioplasty was performe d. Results: Complete recanalization was achieved in three total occlus ions, and partial recanalization was established in a further three; t hus, normal coronary perfusion was attained in six out of 1 0 patients after adjunct excimer laser or balloon angioplasty. The final minimum lumen diameter averaged 1.51 mm and the final residual stenosis diame ter was 27%. In two patients the procedure was unsuccessful but withou t significant complications; two other patients developed limited coro nary perforations without clinical sequelae. Conclusion: Refractory co ronary occlusions were successfully recanalized in six out of 1 0 pati ents using a novel excimer laser catheter. Treatment failures in four patients were not associated with major complications, although limite d coronary perforation occurred in two patients.