Endovascular AAA repair: prevention of side branch endoleaks with thrombogenic sponge. 
To report a technique that might decrease the incidence of lumbar artery endoleaks following endovascular repair (EVR) of abdominal aortic aneurysms (AAAs).  Ninety-three patients (86 males, median age 72 years, range 56 to 88) undergoing EVR with the aortomonoiliac technique were entered into a study to detect and then occlude patent side branches before completion of the endografting procedure.  Prior to deploying the iliac occluder, an aneurysmogram was performed to detect patent aortic side branches.  If these side branches were found, an absorbable gelatin sponge was inserted into the aneurysm sac via the occluder introducer sheath.  The patients were followed with contrast-enhanced spiral computed tomography (CT) at 1 week and 3, 6, and 12 months to detect the presence of endoleaks.  Forty-eight (52%) patients demonstrated patent side branches that were occluded by the insertion of gelatin sponges into the aneurysm sac.  The remaining 45 patients without evidence of side branch flow were untreated.  Ten (10.7%) patients died in the perioperative period, and 15 (16.1%) primary endoleaks (13 proximal, 2 distal) were detected.  This left 68 (73.1%) patients for follow-up, 33 (48.5%) of whom had patent branch vessels treated with the thrombogenic sponge.  The median follow-up was 4 months (range 1 to 17), during which time no side branch endoleak was detected on surveillance CT scans in any of the 68 patients, which included all patients treated with the thrombogenic sponge technique and those in whom no patent side branches had been identified.  We have demonstrated a safe and reliable method of preventing lumbar artery endoleaks following endovascular AAA repair.