Intraoperative Cone Beam CT With One-Month Duplex Surveillance After Standard Infrarenal EVAR: A Single-Center...

To evaluate outcomes after standard infrarenal endovascular aortic aneurysm repair (EVAR) using an institutional pathway of intraoperative cone beam computed tomography (CBCT) followed by one-month duplex ultrasound, compared with standard one-month computed tomography angiography (CTA) surveillance.

This was a single-center retrospective cohort study of 172 patients undergoing standard infrarenal EVAR between May 2012 and March 2023. The final cohort included 63 patients in the CTA surveillance group and 104 patients in the intraoperative CBCT plus one-month duplex ultrasound group. The primary surveillance outcome was freedom from detected endoleak through 24 months. Secondary outcomes included sac enlargement ≥5 mm, aneurysm-related reintervention, rupture, aneurysm-related mortality, all-cause mortality, radiation and contrast exposure, and 30-day reintervention. Freedom from detected endoleak was evaluated using interval-based Kaplan-Meier analysis and compared with an interval-based log-rank test.

Thirty-day reintervention did not differ significantly between groups. Estimated 24-month freedom from detected endoleak was higher in the Cone Beam CT group than in the CTA group (79.7% vs 63.5%; interval-based log-rank χ²(1)=4.017, p=0.045). Sac enlargement ≥5 mm occurred in 6 of 63 CTA patients compared with 0 of 103 Cone Beam CT patients (9.5% vs 0.0%; Fisher exact p=0.0026). Intraprocedural radiation exposure and contrast use were not significantly different between groups. The principal exposure difference between strategies was avoidance of routine one-month CTA in the CBCT and duplex pathway. Post hoc sensitivity analyses adjusting for procedure year attenuated the association between CBCT and any endoleak event through 24 months, supporting cautious interpretation in the setting of temporal cohort assignment.

In selected patients undergoing standard infrarenal EVAR at a single center, intraoperative CBCT followed by one-month duplex ultrasound was feasible and was associated with similar early reintervention rates and higher estimated freedom from detected endoleak through 24 months compared with standard one-month CTA surveillance. These findings should be interpreted cautiously given the retrospective design, temporal cohort assignment, different surveillance modalities, and potential detection bias. Prospective multicenter validation with standardized follow-up imaging is needed before routine one-month CTA can be safely omitted.