The Correlation of Aortic Neck Angle and Length in Abdominal Aortic Aneurysm with Severe Neck Angulation for Prediction of Intraoperative Neck Complications and Postoperative Outcomes after Endovascular Aneurysm Repair

Objectives: Endovascular aneurysm repair (EVAR) in hostile neck has been associated with adverse outcomes. We aimed to determine the association of infrarenal aortic neck angle and length and establish an optimal cutoff value to predict intraoperative neck complications and post-operative outcomes. Methods: This was a retrospective review of intact infrarenal abdominal aortic aneurysm (AAA) with severe neck angulation (> 60 degrees) who underwent EVAR from October 2010 to October 2018. Demographic data, aneurysm morphology, and operative details were collected. The ratio of neck angle and length was calculated the optimal cutoff value of the aortic neck angle-length index. Patients were classified into two groups using latent profile analysis. Intraoperative neck complications, adjunct neck procedures, and early and late outcomes were compared. Results: 115 patients were included. Group 1(G1), aortic neck angle-length index ≤ 4.8, had 95 patients and Group 2 (G2), aortic neck angle-length index > 4.8, had 20 patients. Demographic data and aneurysm morphology were not significantly different between groups except for neck length (P < 0.001). G2 had more intra-operative neck complications than G1 (21.1% vs 55%, P = 0.005). Adjunctive neck procedures were more common in G2 (18.9% vs 60%, P < 0.001). Thirty-day mortality rate was not statistically different. G1 patients had a 5-year proximal neck re-intervention free rate comparable to G2 patients (93.7%G1 vs 87.5%G2, P = 0.785). The 5-year overall survival rate was not statistically different (59.9%G1 vs 69.2%G2, P = 0.891). Conclusions: Patients with aortic neck angle-length index > 4.8 are at greater risk of intraoperative neck complications and adjunctive neck procedures than patients with an aortic neck angle-length index ≤ 4.8. The 5-year proximal neck re-intervention free rate and the 5-year survival rate were not statistically different. The aortic neck angle-length index is a reliable predictor of intra-operative neck complications during EVAR in AAA with severe neck angulation.