Greater Compliance within Instruction for Use for Concomitant Iliac Aneurysms and Adverse Aneurysm Characteristics–Initial Experience with the Nellix Endovascular Aneurysm Sealing System at a Single Institution

Abstract

The Nellix was introduced to Asia in 2014. Data in Asians have been sparse. Twoballoon-expandable stents, each surrounded by a polymer-filled endobag, are deployed in parallel to obliterate and seal the aneurysm. This paradigm shift to treating abdominal aortic aneurysms confers advantages for certain adverse aneurysm morphology that is outside the instruction-for-use (IFU) for standard endovascular aneurysm repair (EVAR) devices. We examine outcomes of 15 Asian patients with concomitant infrarenal aortic and iliac artery aneurysms treated with the Nellix at our institution. Between July 2014 and August 2016, 15 male patients underwent elective EVAS at a single tertiary center by the same team of vascular surgeons and interventional radiologists. Patient demographics, clinical presentations, aneurysm morphology, perioperative complications, and follow-up imaging according to the standardized protocol were studied. Preoperative CT images were analyzed using validated automatic 3-dimensional sizing software EndoSize. The novel stent-graft deployment proves consistent and achieved a 100% technical success. Eleven patients (70%) complied within specified Nellix IFU, as compared to 20% if standard endovascular aneurysm repair (EVAR) IFU was applied. The difference is due to the presence of concurrent common iliac aneurysms (n=5), short neck length (n=3), and angulated necks (n=3). Adjunct procedures included 3 open access endarterectomy with embolectomy, 1 coil embolization of internal iliac artery, 1 bilateral renal artery chimneys, and 1 proximal stent deployment. There was no conversion to open surgery. Average operative time was 133min. Median length of stay was 4days. Thirty-day mortality was 0%. Perioperative morbidity included exacerbation of pre-existing renal impairment (n=6), peripheral vascular disease (n=3), and postimplantation syndrome (n=5). One endoleak (7%) and 2 instances of stent migration (14%) were detected. There was no complication of aneurysm or endobag rupture, limb thromboses, or fracture. Early data in our center are encouraging and highlight high procedural success with minimal complications despite challenging patient anatomy.