Covered versus Bare-metal Kissing Stents for the Reconstruction of the Aortic Bifurcation in the ILIACS registry

Objective: We compared the early and mid-term 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, mid-term 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. Conclusion: In the present multicenter study, the use of kissing stents for the treatment of the aortic bifurcation provided good early and mid-term 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.