Editor's Choice – Influence of Proximal Aortic Neck Diameter on Durability of Aneurysm Sealing and Overall Survival in Patients Undergoing Endovascular Aneurysm Repair. Real World Data from the Gore Global Registry for Endovascular Aortic Treatment (GREAT)

Abstract

Aortic neck diameter is an independent anatomical feature that is poorly understood, yet potentially linked to proximal seal failure and adverse outcome following standard EVAR. The aim of this study was to assess whether large proximal aortic neck (LAN) diameter is associated with adverse outcome using prospectively collected individual patient data from The Global Registry for Endovascular Aortic Treatment (GREAT). A total of 3166 consecutive patients, from 78 global centres, receiving Gore Excluder stent grafts for infrarenal abdominal aortic aneurysm repair between 2011 and 2017 were included. Patient demographics, biometrics, operative details, and clinical outcome were analysed. Patients were divided into two groups: normal baseline proximal aortic neck (NAN) diameter (<25mm on computed tomography aortography), and LAN (≥25mm). Clinical follow up (including imaging) was available for 76.5% of patients 5 years post-intervention. Primary endpoints analysed were Type IA endoleak and any aortic re-intervention up to 5 years post-procedure. A composite endpoint of Type IA endoleak, re-intervention, aortic rupture, or aortic related mortality was also assessed. A total of 1977 (62.4%) patients were classified NAN and 1189 (37.6%) were LAN. Immediate technical success was achieved in 3164 out of 3166 (>99.9%) of cases. Freedom from Type IA endoleak was achieved in 99.3% at 1 year and 97.3% at 5 years (lower in LAN vs. NAN: 96.8% [CI 93.7-98.4] vs. 98.6% [CI 94.5-99.6], p=.007). Freedom from aortic re-intervention was 93.7% at 1 year and 83.2% at 5 years (78.6% [CI 66.0-87.0] LAN vs. 86.0% [CI 81.8-89.3] NAN, p=.11). Freedom from primary composite endpoint was 95.9% at 1 year and 84.9% at 5 years (81.3% [CI 69.2-89.0] LAN vs. 87.0% [CI 81.6-91.0] NAN, p=.066). Five year survival was lower in the LAN group; 64.6% (CI 50.1-75.7) vs. 76.5% (CI 70.7-81.3), p=.03). LAN is associated with delayed Type IA endoleak occurrence and lower overall survival.