Early Results of Shape Memory Polymer Embolization for Endoleak Treatment after Thoracoabdominal Fenestrated/Branched Endovascular Aneurysm Repair.

BACKGROUND

Endoleaks after thoracoabdominal fenestrated/branched endovascular aneurysm repair (TA-F/BEVAR) may require multimodal treatment, including sac access and cavity filling. Shape memory polymer (SMP) is a self-expanding porous scaffold that promotes organized thrombus, is radiolucent, exerts low radial force, and biodegrades. We evaluated SMP embolization to fill endoleak cavities after TA-F/BEVAR.

METHODS

Retrospective review of all patients treated at a single center with IMPEDE-FX Embolization Plugs for endoleak after TA-F/BEVAR (July 2024-June 2026). Outcomes were endoleak resolution, change in sac diameter and volume, complications, and endoleak-related reintervention.

RESULTS

Ten patients (8 male; median age 70) underwent 12 procedures. Median preoperative endoleak volume was 25 mL (range, 3-148 mL); 6 had prior endoleak-directed reintervention. A median 114 plugs were implanted per procedure (range, 29-297). No procedural complications occurred. At a median of 34 days, 5 patients (50%) had complete resolution, 3 (30%) near-complete resolution (residual 1.3-2.0 mL), and 2 (20%) partial resolution (residual 25-32 mL); both of the latter underwent a second SMP procedure achieving near-complete resolution. At last follow-up (median 155 days; range, 30-761 days) no new endoleaks were identified. Sacs regressed in 6 patients and were stable in 4; none expanded.

CONCLUSION

SMP embolization was safe and effective for significant endoleak after TA-F/BEVAR, despite large endoleak volumes and frequent prior failed intervention. All patients achieved substantial endoleak reduction or resolution; most sacs regressed and none expanded. Longer follow-up is needed to establish durability.