Stent Protrusion >20 mm Into the Aorta: A New Predictor for Restenosis After Kissing Stent Reconstruction of the Aortoiliac Bifurcation

Purpose: To determine the long-term patency of aortoiliac kissing stents and to identify predisposing factors for the development of in-stent restenosis (ISR). Methods: A retrospective analysis was conducted of 105 patients (median age 60.9 years; 64 women) with symptomatic aortoiliac occlusive disease who had kissing stents implanted between 2001 and 2015. The indication for kissing stents was severe claudication in 91 (86.7%) patients and critical limb ischemia in 14 (13.3%). Lesions were TASC A in 52 (49.5%), B in 29 (27.6%), C in 4 (3.8%), and D in 20 (19%) patients. Twenty-five (23.8%) patients had heavily calcified lesions. In all, 210 stents were deployed [180 (85.7%) self-expanding and 30 (14.3%) balloon-expandable]. Follow-up included clinical evaluation, ankle-brachial index measurement, and duplex ultrasonography. Results: The median follow-up was 45 months. The primary patency rates were 93%, 86%, and 77% at 12, 24, and 60 months, respectively. Significant ISR developed in 23 (21.9%) patients (12 unilateral and 11 bilateral). Univariate Cox regression analysis revealed older age [hazard ratio (HR) 0.5, 95% confidence interval (CI) 0.31 to 0.81, p=0.004] and larger aortic diameter (HR 0.42, 95% CI 0.25 to 0.7, p<0.001) to be variables favoring long-term patency, while a longer aortic stent segment (HR 1.56, 95% CI 1.16 to 2.09, p=0.003) and a larger discrepancy between the summed stent diameters and the aortic diameter (HR 1.64, 95% CI 1.01 to 2.65, p=0.043) were associated with ISR development. Multivariate analysis showed a longer aortic stent segment to be the only significant determinant of ISR (HR 1.44, 95% CI 1.02 to 2.01, p=0.035). Conclusion: The kissing stent technique can be performed with good long-term patency. Patients whose iliac stents protrude too far into the aorta need closer follow-up.