Friendly Neck Anatomy Does Not Prevent Neck-Related Adverse Events After EVAR

Abstract

Life-long follow-up after EVAR is costly and burdensome to the patient. Follow-up should be stratified based on the risk of EVAR failure. Aneurysm neck is thought to be the single most important risk factor. This study investigated neck anatomy as a predictor of neck-related adverse events after EVAR. This retrospective single-center study included consecutive patients undergoing elective EVAR for infrarenal abdominal aortic aneurysms between 2011- 2016 (n=222) who were followed with yearly imaging until December 2020. Hostile neck was defined as neck length ≤15mm, width ≥28mm, angulation ≥60°, calcification or thrombus ≥50% of circumference or conical neck based on preoperative computed tomography angiography. Neck-related adverse event was defined as aneurysm rupture, any neck-related re-intervention or type 1a endoleak during follow-up. Ninety (41%) patients had hostile neck, and 132 (59%) had friendly neck. There were no differences in 30-day mortality (1% vs. 1%, p=0.78), major adverse events (20% vs. 16%, p=0.43) or re-interventions during the hospital stay (8% vs 4%, p=0.20) between patients with hostile and friendly neck. Estimated survival at 1 year was 89±3% for hostile neck and 95±2% for friendly neck patients (p<0.01). Five-year survival estimates were 51±6% and 66±4%, respectively. Aneurysm-related mortality was higher after six years in patients with hostile neck (p<0.01). Twenty-four patients (11%) suffered neck-related adverse events with mean time-to-event of 3.3±2.8 years, there were no differences between the groups stratified by neck anatomy. Incidentally, preoperative aneurysm diameter was found to be an independent risk factor for neck-related adverse events and aneurysm-related mortality; 53 patients (24%) had aneurysm diameter ≥70mm, which was associated with nearly four-fold risk of neck-related complications during the follow-up. Friendly neck anatomy may not protect from neck-related adverse events after EVAR in the long-term. Especially patients with large aneurysms should be followed closely.