Abdominal Aortic Aneurysm Sac Healing with a Bioabsorbable Shape Memory Polymer

Purpose: To determine the safety and feasibility of filling an abdominal aortic aneurysm (AAA) sac with a novel, bioabsorbable embolic device at the time as endovascular aneurysm repair (EVAR) to promote AAA sac regression and reduce post-EVAR complications.

Materials and Methods: A pair of prospective, multicenter safety studies are each enrolling up to 15 patients in the Netherlands and New Zealand. The implanted devices are composed of shape memory polymer, a self-expanding, porous embolization technology that supports rapid conversion to organized thrombus followed by cellular infiltration and tissue ingrowth. Primary endpoints are 30-day major adverse events (MAEs) and acute technical success, defined as filling the residual flow volume. Secondary outcomes through 2 years include endoleak, sac diameter or volume, AAA-related reintervention, and conversion to open repair.

Results: To date, nine patients undergoing elective infrarenal EVAR underwent concomitant sac filling with shape memory polymer devices. A 100% technical success rate was achieved. No device- or study-related MAEs were reported. Sac regression and absence of endoleak were noted at 6 months. No AAA-related reinterventions or conversion to open repair were reported.

Conclusions: Initial data demonstrate the preliminary safety and feasibility of AAA sac filling with shape memory polymer devices at the same time as EVAR. Further experience and follow-up data will determine the effect of the device on aneurysm sac behavior.