Comparison of intravascular ultrasonography and intraarterial digital subtraction angiography after directional atherectomy of short lesions in femoropopliteal arteries

Abstract

In this study a group of patients undergoing directional atherectomy for localized occlusive disease in the femoropopliteal arteries, the value of intravascular ultrasonography (IVUS) to improve the efficacy of plaque removal was evaluated. The findings obtained by IVUS were correlated with intraarterial digital subtraction angiography (IA DSA) performed during the procedure. In addition, the patency rates at follow-up in patients undergoing atherectomy with and without IVUS were compared. Forty patients were treated by atherectomy because of segmental lesions of the femoropopliteal arteries causing intermittent claudication. Twenty-two patients underwent atherectomy, guided by biplane IA DSA only, and 18 patients were also studied by IVUS. The groups were divided by means of consecutive presentation, IVUS being used in the second part of the study period. The median follow up was 16 months (range, 0 to 40 months). Variables, measured by IVUS during the procedure, were the minimal transverse luminal diameter (MTLD) and the free luminal area. Patency rates at follow-up were determined by regular color flow duplex examinations. Color-flow duplex criteria for occlusions were absence of arterial flow and, for stenosis, a ratio of peak systolic velocities at the diseased segment and a normal segment of 2.5 or greater. Qualitative IVUS assessment prompted additional atherotome passages because of insufficient atheroma removal or nonaesthetic appearance of the vessel lumen in 15 of the 18 patients who underwent this examination. Only in four of these patients would abnormalities at IA DSA have been a reason for further attempts of atheroma removal. As for the quantitative findings during AT, after a first series of atherectomy passes the mean MTLD of the reference lesion resulted in an increase of the MTLD from a mean of 3.3 +/- 0.7 mm to 3.7 +/- 0.6mm (p = 0.001), and the free luminal area increased from a mean of 11.2 +/- 4.8 mm2 to 12.5 +/- 4.5 mm2 (p = 0.001). However the occurrence of restenosis during follow-up was comparable in patients monitored during the intervention by IVUS (1-year patency rate, 57%) and patients not studied by IA DSA only (1-year patency rate, 64%). In addition, the presence of an intimal dissection or a plaque rupture at IVUS examination did not predict restenosis. The application of IVUS resulted in an improved luminal enlargement by directional atherectomy but not in a better 1-year patency rate.