First in Human Aortic Aneurysm Sac Filling with AneuFix Injectable Polymer during Endovascular Aneurysm Repair

Objective: Type II endoleak (T2EL) after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) can lead to aneurysm growth and rupture. Filling the aneurysm sac around the stent graft during EVAR may prevent T2EL. This study evaluated the feasibility and safety of a novel injectable polymer (AneuFix, TripleMed, Geleen, the Netherlands), for sac filling during EVAR in patients at high risk of T2EL. Methods: This first in human, single arm, single centre feasibility trial (ClinicalTrials.govidentifier: NCT04307992) included five patients with infrarenal AAA at high risk of T2EL. During EVAR, a filling sheath was positioned within the aneurysm, and the sac was filled with injectable polymer around the stent graft. Primary outcomes were technical success and safety (serious adverse events (SAEs) related to the procedure or device). Secondary outcomes included AAA diameter, volume, T2EL presence at six and 12 months, procedural metrics, re-intervention, rupture, and death. Post-treatment evaluations were performed by a Data Safety and Monitoring Board after treatment of the second, fourth, and fifth patients. Results: Four men and one woman (median age 68 years; range 63 - 82 years) were treated. Technical success was 100% (five of five), with complete aortic lumen filling. No device related SAEs occurred. One procedure related SAE (1.5 L blood loss via access sheath) resolved without clinical sequelae. Median polymer volume was 50 mL (range 22 - 70 mL) and injection time was seven minutes (range 4 - 13 minutes). The median AAA diameter decreased from 62 mm after procedure to 60 mm and 56 mm at six and 12 months, respectively. AAA volume decreased from 167 mL to 148 mL and 127 mL. No T2ELs or re-interventions occurred during follow up when assessable. Conclusion: In this first in human series, injectable polymer sac filling during EVAR appeared technically feasible and safe, with all patients showing sac shrinkage at 12 months. A multicentre feasibility and safety trial is in progress.