Could Preoperative Neck Anatomy Influence Follow-up of EVAR?

Background: The aim of the study was to assess the clinical utility of strict CT scan surveillance after endovascular abdominal aneurysm repair (EVAR) and evaluate whether the anatomy of abdominal aortic aneurysm (AAA) neck (favorable/hostile) influences regular imaging control.

Methods: A retrospective study of AAA patients who underwent EVAR with aortobi-iliac endoprostheses during 2006-2013 was conducted. Exclusion criteria included other types of devices. Variables analyzed were technical and clinical success, morbimortality, complications (such as endoleaks, sac enlargement), reinterventions, reintervention-free survival, and survival rate. Preoperative CT scans were performed and repeated at 1, 6 (in selective cases), 12, and 24 months postoperatively. Patients were divided into two groups according to preoperative anatomic characteristics: group I (favorable neck) and group II (hostile neck: angle > 60°, length < 15 mm, diameter > 28 mm, and calcification or circumference thrombus ≥50%).

Results: A total of 127 patients with AAA (96.8% male) were included in the study. The mean age of the patients was 75.9 years (range: 51-90 years). The mean AAA diameter was 62.1 mm. Hostile neck was found in 52 patients (40.9%). The technical and clinical success rate was 100% and 30-day mortality was 0.8%. The reintervention-free survival rate was 97.6%, 96.1%, and 93.7% and the survival rate was 97.6%, 96.9%, and 91.3%, during follow-up at 6, 12, and 24 months, respectively. Accumulated complications in proximal sealing occurred in 0%, 0%, and 1.6% in group I and 1.9%, 6.1%, and 7.7% in group II at 1, 12, and 24 months, respectively. Type II endoleaks occurred in 24.3%, 14.3%, and 11.4% in group I and 9.8%, 6.3%, and 6.8% in group II at 1, 12, and 24 months, respectively. No increased diameter was detected at 6 and 12 months. No differences were observed in reinterventions and mortality rate depending on anatomy.

Conclusions: CT scans performed at 6 and 12 months postoperatively did not detect complications or need for reintervention in patients with favorable necks, even in the presence of endoleaks type II, and could therefore be omitted. Hostile necks may compromise proximal sealing and require regular imaging follow-ups.