Covered versus bare metal kissing stents for reconstruction of the aortic bifurcation in the ILIACS registry

Objective: We compared the early and midterm outcomes of polytetrafluoroethylene covered stents (CSs) vs bare metal stents (BMSs) used in the kissing conformation for the reconstruction of the aortic bifurcation in aortoiliac obstructive disease. Methods: A multicenter cohort registry (2015-2019) collected data from 1306 patients who had undergone endovascular treatment of aortoiliac arterial obstructive disease. Only patients who had received bilateral iliac kissing stents for TransAtlantic Inter-Society Consensus (TASC) class C and D lesions were included in the present analysis. The 30-day outcomes, midterm primary patency, and limb salvage rates were compared between the CSs and BMSs in matched patient cohorts after propensity score matching. The follow-up results were analyzed using Kaplan-Meier curves. Cox proportional hazards models were used to identify the predictors of primary patency. Results: A total of 336 patients were treated with kissing stents, 201 with CSs (60%) and 135 with BMSs (40%). In the unmatched cohort, patients receiving CSs were more likely to have critical limb ischemia (41% vs 30%; P = .038), complex iliac lesions, such as TASC D (90% vs 56%; P < .01), and iliac occlusions (59% vs 44%; P < .01). After propensity score matching, 220 patients were selected (110 with CSs and 110 with BMSs), without differences in the clinical presentation (critical limb ischemia, 41% vs 33%; P = .167), or anatomic complexity (TASC D, 66% vs 60%, P = .21; iliac occlusion, 48% vs 49%, P = .89). The 30-day mortality was 0%. The early medical (unmatched, 5% vs 4%, P = 1.00; matched, 5% vs 4%, P = .75) and surgical (unmatched, 5% vs 5%, P = 1.00; matched, 5% vs 3%, P = .72) complication rates were similar between the CSs and BMSs. However, the CSs resulted in a lower risk of intraoperative iliac rupture (0% vs 3.5%; P = .013) and greater ankle-brachial index improvement (0.43 ± 0.22 vs 0.36 ± 0.24; P = .02). At 36 months, the overall primary patency (92% ± 7% vs 92% ± 8%; P = .38), secondary patency (98% ± 3% vs 98% ± 4%; P = .50), and limb salvage (93% ± 9% vs 97% ± 5%; P = .20) rates were similar. In cases of moderate to severe iliac calcification, the CSs showed better results in the matched cohort (100% vs 89% ± 9%; P = .048). On multivariate analysis, CS use (hazard ratio [HR], 1.67; P = .45) did not significantly affect primary patency, but older age (HR, 0.93; P = .03) and kissing stent diameter ≥8 mm (HR, 0.25; P = .03) were significantly associated. Conclusions: In the present multicenter study, the use of kissing stents for the treatment of the aortic bifurcation provided good early and midterm results. CSs were preferred for more complex lesions, were protective from iliac rupture, and allowed for greater ankle-brachial index improvement. The 3-year patency rates were similar between the CSs and BMSs. However, CSs showed improved results in the case of moderate to severe calcification.