Wire Passages of 0.035-inch Looped Wire Technique for Femoropopliteal Long Total Occlusions

Aim: Although it is understood that a looped wire technique using a 0.035-inch wire for femoropopliteal (FP) long chronic total occlusions (CTOs) goes to the subintima, there has been no systematic assessment of wire passages. The purpose of this study is to examine these passages by intravascular ultrasound (IVUS) after looped wire technique for FP long CTOs. Methods: Between March 2012 and October 2014, 57 consecutive FP long CTO lesions (mean lesion length, 246 +/- 42 mm), involving the superficial femoral artery ostium and treated with IVUS-guided endovascular therapy, were enrolled. After IVUS confirmed that the initial wire passage was intraplaque, the looped wire technique was routinely conducted through the CTO body. Based on IVUS findings, the wire passage was classified into 3 types: intraplaque, subintimal, and intramedia. Results: At the FP lesion in the proximal, middle, and distal segments, the wire proceeded intraplaque in 98%, 25%, and 20% cases; subintimal in 2%, 61%, and 52%; and intramedia in 0%, 14%, and 28%, respectively. The success rate of antegrade wiring was 74%, with the remaining 26% cases requiring an additional retrograde approach. Conclusions: The looped wire technique variably proceeds to intraplaque, subintimal, or intramedia, even starting from intraplaque in FP long CTOs.