Prediction and Progression Stratification of Type II Endoleak After EVAR Using Clinical, Anatomical, and Ultrasound...

To identify factors associated with type II endoleak (T2EL) after endovascular aneurysm repair (EVAR) and to stratify sac progression risk in patients with established T2EL using clinical, anatomic, and ultrasound-derived parameters.

This ambispective cohort study included patients undergoing postoperative ultrasound surveillance after EVAR. Using the first eligible postoperative ultrasound revisit at the study center as the index time point, perioperative clinical and imaging data up to that revisit were collected retrospectively, and patients were prospectively followed thereafter. Multivariable logistic regression was used for occurrence prediction. In T2EL, sac progression was defined as an increase of at least 5 mm in maximal anteroposterior sac diameter from baseline, and ordinal logistic regression was used to develop a progression score.

A total of 172 patients were included, 40 with T2EL and 132 without. Hypertension, greater mural thrombus thickness, nonsmoking status, more patent lumbar arteries, a lower inferior mesenteric artery patency score, and unilateral internal iliac artery embolization were retained in the full T2EL occurrence model. The occurrence model showed high apparent discrimination (apparent area under the curve [AUC] = 0.934), and bootstrap sensitivity analysis showed an optimism-corrected AUC of 0.915. Sac enlargement was more frequent in T2EL. Among T2EL patients, the high-risk group had more patent lumbar arteries, more concomitant iliac aneurysms, lower inferior mesenteric artery patency scores, thicker mural thrombus, and higher systolic pressure, systolic flow, endoleak volume, and endoleak-to-sac volume ratio. The progression model showed moderate discrimination (apparent AUC = 0.751).

T2EL occurrence after EVAR was associated mainly with preoperative anatomy, collateral vessel conditions, and baseline patient factors, whereas sac progression in established T2EL appeared to be associated with exploratory ultrasound-derived hemodynamic and volumetric burden. These findings may help refine postoperative surveillance and selection for reintervention.Clinical ImpactType II endoleak after EVAR should not be managed as a uniform or inherently benign finding. In our cohort, T2EL occurrence was associated mainly with preoperative anatomy, collateral-vessel status, and baseline patient factors, whereas sac progression among established T2EL cases appeared to be associated with exploratory ultrasound-derived hemodynamic and volumetric burden. This 2-step framework may provide an exploratory strategy for postoperative risk stratification beyond simple endoleak detection and may help identify patients requiring intensified surveillance. However, because model development was based on limited T2EL events and ultrasound-derived measurements require broader external validation despite institutional diagnostic-performance and interobserver reliability assessments, clinical use remains premature.