Optimizing Laser Atherectomy for Different Lesion Morphologies

Abstract

Objective. To understand the impact of fluence and repetition rate on outcomes of superficial femoral artery (SFA) and popliteal artery laser atherectomy based on lesion type (calcific, homogenous, heterogeneous, and restenosis). Methods. Patients with de novo or restenotic (≥50%) SFA and popliteal artery atherosclerotic disease were enrolled. All lesions were sequentially treated with Turbo-Power laser atherectomy (Spectranetics) at 3 predetermined intensity settings: low (fluency, 40 mJ/mm2; repetition rate, 60 Hz); medium (fluency, 60 mJ/mm2; repetition rate, 40 Hz); and high (fluency, 60 mJ/mm2; repetition rate, 60 Hz). Angiography and intravascular ultrasound (IVUS) were performed to characterize plaque morphology and evaluate residual stenosis. Follow-up was 30 days and medical records were reviewed through 12 months for adverse events. Results. Forty-five patients with 57 lesions (12 homogenous, 15 heterogeneous, 15 calcific, and 15 restenotic) were enrolled. Rutherford classification ranged from 2-5, average lesion length was 98.2 ± 91.2 mm, and average diameter stenosis was 82.5 ± 17.9%. Compared with baseline, all lesion types had significant improvement in final postprocedure (atherectomy + any adjunctive therapies) diameter stenosis. Prior to adjunctive therapy, the heterogeneous and restenosis groups saw improvement in minimum lumen area following each stage of the laser treatment. However, the calcific and homogenous groups saw little change in minimum lumen area between the medium- and high-intensity laser treatments. Within 6 months, a total of 6 patients had target-lesion revascularizations. No major amputations or deaths occurred through follow-up. Conclusion. Laser intensity settings during atherectomy should be selected based on lesion morphology. IVUS was essential in defining plaque morphology.