UNLABELLED: This study is a preliminary report evaluating the use of laser radiation to heat a metal-capped fiber for arterial recanalization. The method was compared to the currently used bare-ended fiber for recanalization of occluded vessels. The model used was a human coronary artery xenograft transplanted in the femoral artery of the dog. At 4 weeks following the transplantation, laser recanalization was attempted using the heated metal probe ("hot tip") in five arteries and the bare fiber in another five arteries. RESULTS: 1) Angiography demonstrated recanalization in all five arteries treated with the "hot tip" and three of the five arteries treated with the bare fiber. 2) Only one perforation occurred with the "hot tip," whereas three perforations occurred with the bare fiber. 3) The larger metal cap was capable of creating a wider channel in the occluded arterial segment. Although the trend favored the heated metal cap in terms of recanalization and less perforation than the bare fiber, the total number of experiments were not adequate to demonstrate statistical significance. Microscopic examination of the vessels recanalized by either technique was similar. Characteristic charring at the recanalization site was seen regardless of the technique used. These observations suggest that the effect of direct laser radiation on plaques is predominantly a thermal effect. Although these results would suggest utilization of a metal-capped fiber for vascular recanalization, more studies need to be done to confirm these preliminary findings.
UNLABELLED: This study is a preliminary report evaluating the use of laser radiation to heat a metal-capped fiber for arterial recanalization. The method was compared to the currently used bare-ended fiber for recanalization of occluded vessels. The model used was a human coronary artery xenograft transplanted in the femoral artery of the dog. At 4 weeks following the transplantation, laser recanalization was attempted using the heated metal probe ("hot tip") in five arteries and the bare fiber in another five arteries. RESULTS: 1) Angiography demonstrated recanalization in all five arteries treated with the "hot tip" and three of the five arteries treated with the bare fiber. 2) Only one perforation occurred with the "hot tip," whereas three perforations occurred with the bare fiber. 3) The larger metal cap was capable of creating a wider channel in the occluded arterial segment. Although the trend favored the heated metal cap in terms of recanalization and less perforation than the bare fiber, the total number of experiments were not adequate to demonstrate statistical significance. Microscopic examination of the vessels recanalized by either technique was similar. Characteristic charring at the recanalization site was seen regardless of the technique used. These observations suggest that the effect of direct laser radiation on plaques is predominantly a thermal effect. Although these results would suggest utilization of a metal-capped fiber for vascular recanalization, more studies need to be done to confirm these preliminary findings.