Evaluation of a prototype steerable angioscopic laser catheter in a canine model: a feasibility study

To overcome some of the persisting technical problems related to laser angioplasty, a new catheter was designed and investigated in a canine model. This 5F catheter contained a deflectable tip for steerability, an angioscope, and a laser fiber. Catheter steerability, angioscopic function, and the effects of a 480 nm flash lamp pumped pulsed dye laser on normal canine vessel walls were evaluated. Steering, angioscopic guidance, and application of laser energy were easy and fast to perform in a bloodless vessel segment. Maintaining a condition of bloodlessness at the target site, critical to angioscopic guidance, proved to be the most difficult part in this prototype evaluation. It was noted that the 480 nm pulsed dye laser did not cause macroscopic alterations or perforations to the normal vessel wall. We conclude that a relatively simple deflection mechanism of a small-caliber angioscope provides the kind of aiming ability requisite for precise endovascular therapy. Complete bloodlessness of the area is necessary for both viewing and laser ablation at 480 nm.

Two-year follow-up after laser thermal balloon angioplasty (LTBA) in lower extremities: initial experience

We describe the results obtained with the use of laser thermal balloon angioplasty (LTBA) in the treatment of atherosclerosis obliterans of the lower limbs in 37 patients (34 males, 3 females, mean age 58 +/- 9 years) with occlusive arterial disease (Fontaine stages II-IV) presenting 39 significant lesions. Immediate results and two years of clinical follow-up are analyzed. Initial ankle/brachial Doppler index was 0.51 +/- 0.17. Eighteen lesions were located in the iliac area (13 stenoses 2.3 +/- 1 cm and 5 occlusions 4.2 +/- 3 cm) and 21 lesions in the femoropopliteal area (5 stenoses 2.6 +/- 2 cm and 16 occlusions 5.7 +/- 3 cm). A percutaneous procedure was used in 38 cases. In only one case was femoral dissection needed. The laser source was argon in 26 cases and Nd-YAG in 13. Initial success was 85% (89% in iliac lesions and 81% in femoropopliteal lesions; 100% in stenoses and 70% in occlusions). The presence of occlusion (p less than 0.01) and/or calcium (p less than 0.05) negatively influenced the immediate results. No major complications were observed; seven (17%) minor complications occurred. Ankle/brachial Doppler index after treatment was 0.82 +/- 0.21. Cumulative clinical patency for successfully treated patients after two-year follow-up was 91%. LTBA thus represents an effective and less aggressive way of treating peripheral atherosclerosis obliterans. In spite of some limitations, it is useful in selected patients. The results of this study are very much like those in the literature for similar series and early experience.