Mechanism of luminal gain with plaque excision in atherosclerotic coronary and peripheral arteries: assessment by histology and intravascular ultrasound.

OBJECTIVES: Using intravascular ultrasound (IVUS) and histology, the purpose of this study was to evaluate the occurrence of arterial wall overstretch and Dotter effect following revascularization with a plaque excision (PE) catheter compared with balloon angioplasty. BACKGROUND: Previous studies have demonstrated the safety and feasibility of plaque excision for the treatment of de novo coronary and peripheral atherosclerotic disease. However, whether mechanical vessel dilatation related to catheter insertion contributes to gains in the final luminal diameter is uncertain. METHODS: Treatment with PE was assessed in both a porcine model (6 lesions treated with balloon angioplasty or PE) using histology and in humans with IVUS. In the latter part of the study, IVUS study was performed before and immediately following PE in 21 patients with either coronary artery disease (N = 13) or femoral artery disease (N = 8). Ultrasound measures in the femoral artery group were then compared with a control group of atherosclerotic lesions treated with conventional angioplasty that was matched according to lesion location and vessel diameter. RESULTS: Among individuals with coronary and peripheral arterial lesions treated with PE, the relative increases in luminal area secondary to reductions in plaque volume were 89% and 83%, respectively, with minimal increase in vessel diameter. In contrast, balloon angioplasty was associated with significantly greater vessel expansion and less plaque volume reduction. Vessel dissection also tended to occur less frequently and to a lesser extent with PE. CONCLUSIONS: Improvement in luminal dimensions using PE is principally due to a reduction in plaque volume rather than mechanical vessel expansion. The potential to increase luminal area while minimizing arterial dissection and barotrauma merits further clinical study with this method of revascularization.