Mid-Term Outcomes of the Iliac Branch Endoprosthesis with Standardized Combinations of Bridging Stent-Grafts for Endovascular Treatment of Aortoiliac Disease with or Without Co-existing Hypogastric Aneurysms (The HYPROTECT Study)

Purpose: To evaluate retrospectively the 2-year outcomes of the Gore Excluder Iliac Branch Endoprosthesis (IBE) in patients with and without coexisting hypogastric artery (HA) aneurysms in a large contemporary multicentric European experience using dedicated bridging devices. Methods: The study included all consecutive patients treated at participating institutions with the Gore Excluder IBE device who received a covered stent (i.e., stent-graft) from the same manufacturer. Technical success was defined as deployment of endografts with complete exclusion of the aneurysm(s), patency of target vessels, and absence of type 1 and 3 endoleak. Assessment of follow-up outcomes included freedom from HA branch instability defined as the composite cumulative endpoint of any HA branch-related complication. Results: A total of 437 patients were included for analysis from 22 European vascular surgery centers. Patients were categorized into two subgroups: subgroup A (n = 269) if they did not have concomitant hypogastric aneurysms, otherwise they were categorized into subgroup B (n = 168). Finally, 78 (18%) had bilateral IBE with a total of 515 IBE included in the study. Balloon expandable stents were deployed in 19 (6.3%) subgroup A patients compared with 46 (21.7%,) in subgroup B, p <.001. The two-year estimate for freedom of HA branch instability was significantly higher for patients in group A as compared with patients in group B (94% vs. 90%, p =.045). At univariate regression, the number of stent-grafts used was associated with higher risk of iliac branch instability (p =.021), while in multivariate regression for the use of more than 2 bridging stent-grafts the risk of instability increased by 2.35 times. Conclusions: This large contemporary European multicentric experience with the use of the Gore Excluder IBE in patients with or without associated HA aneurysms shows satisfactory mid-term outcomes when the device is used in conjunction with both self-expandable and balloon-expanding stent-grafts from the same manufacturer. Although primary patency of the iliac branch was as high as 90%, caution and strict follow-up must be exercised when multiple bridging stent-grafts are used over longer distances.