Laser wire for crossing chronic total occlusions: 'Learning phase' results from the U.S. TOTAL trial

The Prima laser guidewire system (Spectranectics Corp., Colorado Springs, CO) consists of an 0.018'' hypotube containing a bundle of 45-μm optical fibers coupled to a pulsed excimer laser operating at a tip fluence of 60 ml/mm² and a repetition rate ranging from 25-40 Hz. This laser guidewire was specifically designed to cross total occlusions refractory to passage with conventional wires. The Prima wire was evaluated in a feasibility study at 15 U.S. centers. Following failure to cross s total occlusion with approved guidewires, the Prima wire was utilized in 179 patients. Average age of subjects was 61 yr. Lesion locations included left anterior descending (36%), right (45%), and circumflex (19%) coronary arteries. Mean angiographic age of total occlusions was 70 wk (range, 2- 1,020 wk, median, 14 wk). The use of the Prima wire either solely or in combination with conventional guidewires resulted in successful crossing in 61% of these previously impenetrable occlusions. Failure of the device was commonly related to length of the occlusion and tortuosity along the occluded pathway. Major complications included myocardial infarction in 7 patients (3.9%), tamponade in 3 (1.7%), and death in 2 (1.1%). This 'learning phase' pilot study confirmed the feasibility of a laser guidewire in chronic total occlusions that are resistant to passage of conventional guidewires. An extended registry at these investigative sites is planned.