Preliminary results of endovascular aneurysm sealing from the multicenter Italian Research on Nellix Endoprosthesis (IRENE) study

Objective: Because of advances in technology and experience of the operator, endovascular aneurysm repair (EVAR) has supplanted open repair to treat abdominal aortic aneurysm (AAA). The low 30-day mortality and morbidity of EVAR make the endovascular approach particularly suitable for patients at high surgical risk. However, endoleak or endograft migration requiring secondary intervention or open surgical conversion is a limitation of EVAR. The Nellix system (Endologix, Inc, Irvine, Calif) has been designed to seal the entire AAA to overcome these limitations with EVAR. We report the results of a retrospective, multicenter study with endovascular aneurysm sealing (EVAS) aimed to assess technical success, procedure-related mortality, complications, and reinterventions. Methods: This study included patients selected for elective treatment with the Nellix device per the endovascular repair protocol at 16 Italian vascular centers. All patients were enrolled in a postoperative surveillance imaging program including duplex ultrasound investigations, computed tomography, and magnetic resonance controls following local standards of care. Results: From 2013 to 2015, there were 335 patients (age, 75.5 ± 7.4 years; 316 men) who underwent elective EVAS. In 295 cases (88.0%), EVAS was performed under standard instructions for use of the Nellix system. Preoperative aneurysm diameter was 55.5 ± 9.4 mm (range, 46-65 mm). The inferior mesenteric artery and lumbar arteries emerging from the AAA were patent in 61.8% and 81.3% of cases, respectively. Chimney grafts were electively carried out in eight cases (2.4%). One (0.3%) intraprocedural type IB endoleak was observed and promptly corrected. Device deployment was successful in all patients, with no perioperative mortality. Early (≤30 days) complications included 1 (0.3%) type IA endoleak, 2 (0.6%) type II endoleaks (0.6%), 2 (0.6%) stent occlusions (0.6%), 3 (0.9%) distal embolizations, and 2 (0.2%) femoral artery dissections. Six (2.9%) patients underwent reinterventions. At 1-year follow-up, complications included 3 (1.1%) type II endoleaks, 4 (1.4%) type IA endoleaks, 1 (0.3%) type IB endoleak, 2 (0.7%) distal stent migrations, 5 (1.8%) distal embolizations, and 1 (0.3%) stent occlusion. Twelve patients (3.7%) underwent reinterventions, including four (1.4%) surgical conversions due to aortoduodenal fistula (1), endograft infection (1), and type IA endoleak that was unsuccessfully treated percutaneously (2). Two AAA-related deaths occurred. Freedom from aneurysm-related reintervention was 98.3% at 1-month and 94.7% at 12-month follow-up. Conclusions: The preliminary results of this real-world multicenter study showed that EVAS with Nellix for the management of AAAs appears feasible. This device platform is associated with acceptable procedure-related mortality and low overall complication and reintervention rates. Definitive conclusions on the value of this novel device await long-term follow-up data.