Type 2 endoleak after endovascular aortic aneurysm repair (EVAR) is common (8-44%). Interventions for type 2 endoleak have had a technical success rate of more than 80%. However, the clinical success rates, defined as aneurysm sac stabilization or shrinkage, have been significantly lower. The aim of this study was to assess the technical success, safety, and clinical benefit of AneuFix (TripleMed, Geleen, The Netherlands), a novel polymer-based material that is directly injected into the aneurysm sac in patients with a type 2 endoleak and a growing abdominal aortic aneurysm (AAA).

A prospective, multicenter, pivotal trial was conducted (ClinicalTrials.gov: NCT02487290). Patients with a type 2 endoleak and AAA growth were included. Patients with a patent inferior mesenteric artery connected to the endoleak were excluded. The endoleak cavity was punctured through a translumbar approach after cone-beam computed tomography (CT) and software needle planning. Direct angiography of the endoleak was performed, and all lumbar arteries connected to the endoleak were visualized (figure 1). Next, the AneuFix polymer was injected into the cavity of the endoleak, including a short segment of the lumbar arteries (figure 2). Initially the polymer has a low viscosity but after being injected into the endoleak it regains a very high viscosity and the cured AneuFix implant becomes stable, but remains flexible. The primary end point was technical success. The secondary end points were clinical success (defined as the absence of AAA growth at 6 months on CT angiography, serious adverse events, reinterventions, and neurological abnormalities. CT angiography follow-up was performed at 1 day, and 3, 6 and 12 months after EVAR. We have reported the results for the first 18 patients. All outcomes are reported as medians with interquartile ranges (IQR).

Of the 18 patients. 14 were men and 4 were women, with a median age of 78 years (IQR, 76-81 years). The pre-AneuFix AAA diameter was 80 mm (71-85 mm) and aneurysm growth after EVAR was 16 mm (10-21 mm). Two procedures were performed under general anaesthesia and 16 procedures under local anaesthesia. Technical success was 94% (17/18 patients); in one patient we could not puncture the endoleak cavity, in the other 17 patients it was possible to puncture the endoleak cavity and to inject the AneuFix polymer. The AneuFix volume injected was 14 mL (10-20 mL) and the AneuFix injection time was 5 min (5-8 min). During the injection, fluoroscopy was continuously used with a total fluoroscopy time of 9 min (7-11 min) and a radiation exposure of 486 mGy (253-663 mGy). The total procedure time was 1h and 25 min (1h 10 min-1h 47 min) and in total 100 mL (30-110 ml) contrast volume was used. Clinical success at 6 months was 73% (11/15 patients). Two patients showed persistent significant AAA growth with the endoleak still being present, most likely due to insufficient endoleak filling. In one patient a type 1a endoleak was found and in another patient the reason for persistent aneurysm growth was not clear. No serious adverse events related to the procedure or AneuFix material were reported. No neurological disorders were reported. There were two adverse events, one patient suffered from flank pain after the procedure and one patient developed a urinary tract infection. Both adverse events spontaneously resolved.

The first results of type 2 endoleak treatment with AneuFix polymer in patients with a growing aneurysm have shown that it is technically feasible, safe, and clinically effective at 6 months.

AneuFix collaborators: Chrit M Stassen Joost MJ Botman Boudewijn L Reichmann Rombout R Kruse Bas-Jeroen van Kelckhoven Erik G Vermeulen