EXTENT Study: Medium-term Outcomes of EXTra-design Engineering Inner-Branch ENdografts for the Treatment of Complex Aortic Aneurysms from a Multicentre Collaboration.

OBJECTIVE: This study aims to present the medium-term outcomes of Extra-Design engineering endografts with inner branches (EDE-iBEVARs, Artivion) in endovascular aortic repairs of complex aneurysms building upon promising early results.

METHODS: A retrospective, international, multi-centre study was conducted including consecutive patients who underwent complex endovascular aortic repairs using EDE-iBEVARs between 2018 and 2022. Patient demographics, aneurysm anatomical features, procedural details, reinterventions, complications, and endograft failures during follow-up were assessed. The primary outcome was aneurysm related mortality. Secondary outcome measures included the freedom from all-cause mortality and reintervention, technical and clinical success, late related complications including branch instability, endoleaks and serious adverse events.

RESULTS: Our study encompassed a total of 260 patients across 13 European centres. The cohort included patients with thoracoabdominal aortic aneurysm (n=116), suprarenal or juxta-renal aneurysms (n=95), and those who had previous open repair or previous EVAR with type 1A endoleak (n=49). Out of 982 possible inner branches (937 antegrade and 45 retrograde), 962 (98%) were successfully cannulated and bridged with covered stents during the index procedure. Overall, the endograft was successfully deployed in 98% of patients and 93% were discharged from hospital following surgery. At 3 years, freedom from aneurysm related mortality was 97%, while the freedom of all-cause mortality was 89%. Freedom from reinterventions was 91% and 76% at 1 and 3 years respectively. The rate of late complications such as endoleaks or branch instability events was 12% (n=30). The late branch occlusion rate during follow up was 1.5% (n=15), of which 12 were renal branches.

CONCLUSION: EDE-iBEVARs demonstrate satisfactory medium-term outcomes with reintervention rates comparable to other endografts. Encouragingly, rates of branch patency were high and major adverse events were low. This technology could expand the treatment options for patients with challenging complex aortic conditions.