LAUSR

PURPOSE The purpose of this study was to compare outcomes of internal iliac artery (IIA) stenting using balloon-expandable (BESG) or self-expandable stent-grafts (SESG) during endovascular repair of aortoiliac aneurysms with iliac branch endoprosthesis (IBE, WL Gore Flagstaff AZ). METHODS We retrospectively reviewed all consecutive patients treated for aortoiliac aneurysms using IBE between 2014-2020. IIA stenting was performed using either the IIA side branch SESG or a Gore VBX® BESG (WL Gore, Flagstaff AZ). Indications for use of BESGs were "up-and-over" IBE technique for type IB endoleak following prior EVAR, short IIA length and need for IIA extension into divisional branches (outside instructions for use[IFU]). End-points included technical success, freedom from buttock claudication, primary IIA patency, and freedom from IIA branch instability (e.g. branch-related death or rupture, occlusion, disconnection, or reintervention for stenosis, kink or endoleak), freedom from type IC/IIIC endoleak and freedom from secondary interventions. RESULTS There were 90 patients, 86 males and four females, with mean age of 74±7 years old treated by EVAR with 108 IBEs. Choice of stent was BESG in 43 and SESG in 65 targeted IIAs. BESGs were used more frequently in patients with prior EVAR (22 vs 2%, P =0.003,), isolated IBEs (31 vs 2%, P <0.001) and in patients with IIA aneurysms requiring stenting into divisional branches (36 vs 5%, P <0.001). Technical success was similar for BESG and SESGs (97% vs 100%, P 0.40), respectively. Mean follow-up was 25±16 months (range 11-34). At 2-years, freedom from buttock claudication was 100% for BESG and 95±3% for SESG (Log-rank 0.26), with no difference in primary patency (BESG, 100% vs SESG, 94±4%, Log-rank 0.94). There were four (9%) IIA-related endoleaks in the BESG group and one (2%) in the SESG group (P=0.08). Freedom from IIA branch instability was 87±6% for BESG and 96±3% for SESG at 2-years (Log-rank 0.043). Freedom from type IC/IIIC endoleak was 87±7% for BESG and 98±2% for SESG at the same interval (Log-rank 0.06). There was no difference in freedom from reinterventions for BESG and SESG (92±6% vs 98±2%, Log-rank 0.34), respectively. CONCLUSION BESGs were used more frequently during IBE procedures indicated for failed EVAR, isolated common iliac aneurysms, and IIA aneurysms requiring extension into divisional branches. Despite these differences and BESG being used outside IFU, both stent types had similar primary patency, freedom from buttock claudication, and freedom from reinterventions. However, BESGs were associated with higher rates of IIA-related branch instability.