Long-term Evaluation of Proximal Aortic Neck Dilatation After Endovascular Abdominal Aortic Aneurysm Repair With a Variety of Contemporary Endografts.

Purpose: To measure the long-term proximal aortic neck dilatation (AND) after elective endovascular aortic aneurysm repair (EVAR) with a variety of contemporary, third-generation, endograft devices.

Materials and methods: This is a noninterventional prospective cohort study of 157 patients that underwent standard EVAR with self-expanding abdominal endografts. Patients' recruitment lasted from 2013 to 2017, and postoperative follow-up was up to 5 years. A computed tomography angiography (CTA) was performed at the first month and then at 1, 2, and 5 years. Proximal aortic neck's (PAN) basic morphological characteristics (diameter, length, angulation) were measured based on the analysis of CTA in a standardized fashion. Neck-related adverse events, such as migration, endoleak or rupture, and reinterventions were recorded.

Results: Significant straightening of the PAN was evident even in the first-month CTA with concurrent neck shortening that became significant at 5 years. Both the suprarenal aorta and the PAN significantly dilated overtime, with PAN dilating more progressively. Mean neck dilatation at the juxtarenal level was 0.8±0.4 mm at 1 year, 1.8±0.8 mm at 2 years, and 3.9±1.7 mm at 5 years, with a mean neck dilatation rate of 0.07 mm/month overall. The incidence of AND ≥2.5 mm was 37.2% at 2 years and 58.1% at 5 years after EVAR and was considered important (≥5 mm) in 11.5% of patients at 2 years and 30.6% of patients at 5 years. A multivariate analysis performed showed that the endograft oversizing, the preoperative neck diameter, and the preoperative abdominal aortic aneurysm sac diameter served as independent predictors of AND at 5 years. At the 5-year follow-up, 8 late type Ia endoleaks (6.5%) and 7 caudal migrations (5.6%) were identified, while no late ruptures were reported. In total, 11 late endovascular reinterventions (8.9%) were performed. Overall, proximal neck-related adverse outcomes (5/7 migrations and 5/8 endoleaks) and reinterventions (7/11) were significantly associated with the presence of important late AND.

Conclusion: Proximal AND after EVAR is common. It can influence the long-term durability of proximal endograft fixation and is significantly associated with adverse outcomes, often leading to reinterventions. A systemic and extended surveillance protocol is needed for maintenance of good long-term results.

Clinical impact: This is a thorough and systematic analysis of the long-term geometric remodeling of the proximal aortic neck after EVAR, that highlights the importance of a strict, and extended surveillance protocol for maintenance of good long-term results of EVAR.