Impact of changing PSVR thresholds on the patency rates of SFA recanalisation with self-expanding nitinol stents

Abstract

The primary patency of superficial femoral artery (SFA) stents is evaluated by measuring PSVR. However, each trial uses a different definition of PSVR. We investigated the impact of changing PSVR thresholds on the patency rates of SFA recanalisation with self-expanding nitinol stents. A single-centre retrospective study was conducted. Between 2003 and 2006, 76 consecutive patients (83 limbs) were treated using nitinol self-expanding stents for SFA disease. Primary patency was defined as categories 1 (PSVR <2.0), 2 (PSVR <2.4) and 3 (PSVR <2.85). The mean follow-up time was 51±27 months. For one, five, and seven years, Kaplan-Meier estimates for primary patency rates were 62.6%, 36.8%, and 27.6%, respectively, in category 1; 75.2%, 46.5%, and 37.1%, respectively, in 2; and 75.2%, 46.1%, and 46.1%, respectively, in 3. The primary patency between categories 1 and 3 (p=0.038) was significantly different. No difference was observed between categories 2 and 3 (p=0.786), and a trend for differences was observed between categories 1 and 2 (p=0.069). PSVR definition may influence the reported long-term patency rate of a SFA stent. We should consider the definition of restenosis in each trial.