Predictors of primary patency failure in Wallstent self-expanding endovascular prostheses for iliofemoral occlusive disease.

Abstract

We studied the factors that affected the primary patency and the clinical and procedural success of WALLSTENTS (stents) that were used at our institution from 1 March 1994 to 30 October 1995 for the treatment of iliac and femoral artery occlusive disease. This prospective study comprised 63 patients with 82 lesions. Follow-up was performed for a mean duration of 18.7 months. Pre- and post-procedural duplex ultrasonography, together with estimation of ankle-brachial index scores, was performed on all patients, and additional studies were performed at clinical follow-up if indicated. The technical success rate was 100%. Ankle-brachial index scores improved considerably from 0.52 +/- 0.21 before the procedure to 0.73 +/- 0.27 after the procedure. The significant predictors by univariate analysis of primary patency failure were: Fontaine class III or IV (P = 0.044); femoral location (P = 0.004); lesion length > 100 mm (P = 0.010); poor or moderate outflow (P = 0.026); and number of stents > or = 3 (P = 0.012). Cox regression analysis showed that > or = 3 stents (risk ratio = 5.61), poor or moderate outflow (risk ratio = 6.05), and femoral location (risk ratio = 5.18) were the significant predictors of primary patency failure. Femoral lesions required more stents than did iliac lesions (2.2 +/- 0.8 vs 1.3 +/- 0.5). Primary patency rates for iliac and femoral stents were 86% and 49%, respectively, at 12 months, and 82% and 41% at 24 months.