Covered and Bare-Metal Stents to Treat Iliac Artery Occlusions Compared Using Propensity Score Modeling
July 26, 2017—In European Journal of Vascular and Endovascular Surgery (EJVES), Michele Piazza, MD, et al published findings from a study that aimed to compare outcomes of self-expanding polytetrafluoroethylene-covered stents with bare-metal stents (BMSs) in the treatment of iliac artery occlusions (2017;54:177–185).
As summarized in EJVES, between January 2009 and December 2015, 128 iliac arteries were stented to treat iliac artery occlusions. A covered stent was implanted in 78 iliac arteries, and a BMS was implanted in 50 arteries. After propensity score matching, 94 limbs were selected and underwent stenting (47 for each group). Thirty-day outcomes and midterm patency were compared; follow-up results were analyzed with Kaplan-Meier curves.
Iliac lesions were classified by limb as TASC B (19%), C (21%), and D (60%). Technical success was 98%.
The investigators reported that comparing covered stents versus BMSs, the early cumulative surgical complication rates (12% vs 12%; P > .99) and 30-day mortality rates (2% vs 2%; P > .99) were equivalent.
At 36 months (average 23 ± 17 months), overall primary patency was similar between covered stents and BMSs (87% vs 66%; P = .06). This finding was maintained after stratification by TASC B (P = .29) and C (P = .27), but for TASC D, covered stents demonstrated a higher patency rate compared with BMSs (88% vs 54%; P = .03). In particular, patency was better for covered stents for iliac artery occlusion > 3.5 cm in length (P = .04), total lesion length > 6 cm (P = .04), and occlusions with calcification > 75% of the arterial wall circumference (P = .01).
Overall, the use of self-expanding covered stents for iliac artery occlusions has similar early and midterm outcomes compared with BMSs. Even if further confirmatory studies are needed, covered stents seem to have higher midterm patency rates than BMSs for TASC D lesions, iliac artery occlusions with a total lesion length > 6 cm, occlusion length > 3.5 cm, and calcification involving > 75% of the arterial wall circumference. These specific anatomical parameters may be useful to the operator when deciding between covered stents and BMSs during endovascular planning, concluded the investigators in EJVES.