SS24 - Five Year Outcomes of the PRESERVE II Zenith Iliac Branch Pivotal Clinical Trial

Objectives: The PRESERVE II study evaluated the safety and effectiveness of the investigational Zenith Iliac Branch Graft (ZBIS) with the iCast covered stent to maintain perfusion of the internal iliac artery during EVAR in patients with insufficient distal landing zone within the CIA. This study was initiated after device integrity issues were observed using an investigational bridging stent in the PRESERVE I study.

Methods: This study was a prospective, multicenter, non-randomized study conducted among 18 US sites. Patients were enrolled between 2014-2015, with follow-up to 5 years. The primary endpoint was 6-month freedom from patency-related interventions (performance goal of 55%). Secondary endpoints were 30-day freedom from morbidity (performance goal of 46%) and 6-month branch vessel patency. Events underwent independent core lab and clinical event committee adjudication.

Results: Forty patients (38M/2F, mean age 67.8 years) were treated; devices were implanted as intended in 100% of patients. Imaging follow-up availability was 100% (37/37) at 1 year. Six-month freedom from patency-related intervention was 100% (39/39), 30-day freedom from morbidity was 85% (34/40), and 6-month branch vessel patency was 100% (37/37). Major adverse events at 12 months included 6 patients with stroke (1), ileus (1), type Ib endoleak (1), leg ischemia (1), and impotence (2). There was one case of 7 mm ipsilateral iliac aneurysm growth at 4 years that was associated with a type Ib endoleak but left untreated. Additionally, there was one case of bilateral buttock claudication at 2 years. Five-year follow-up was available in 75% (30/40) patients with complete imaging in 65% (26/40). Freedom from all-cause mortality at 5-years was 88.9%. There was no aneurysm-related mortality. There were 4 late occlusions related to the ZBIS: 2 in the EIA segment, both treated with thrombectomy and stent placement, and 2 in the iliac branch segment, both of which were symptomatic but managed expectantly. Five-year freedom from patency-related intervention was 100%. In total, 9 patients required 15 secondary interventions, with 6 ipsilateral to the ZBIS. The treated iliac aneurysm size was decreased in 27% (7/26) of patients and unchanged in 73% (19/26). There were no ruptures, type III endoleaks, migrations, or device integrity issues.

Conclusions: The early results of the PRESERVE II study exceeded its primary and secondary endpoints with their respective performance goals. The 5-year outcomes support the sustained safety and effectiveness of the ZIBS in combination with the Atrium iCast covered stent to preserve internal iliac artery perfusion during EVAR.