Association of longitudinal aortoiliac morphometric changes after endovascular aneurysm repair with outcomes

Background: Post-EVAR morphometric remodeling beyond sac diameter is incompletely characterized. We evaluated longitudinal aortoiliac elongation/tortuosity and their prognostic value for endoleak and sac dynamics. Methods: In 529 consecutive EVAR patients (median follow-up 46 months) centerline and Euclidean lengths and tortuosity indices were measured on all CT angiograms using a standardized protocol including centerline length, Euclidean length, and tortuosity. Mixed-effects models assessed temporal trends. Logistic models adjusted for follow-up duration and hostile neck anatomy examined predictors of endoleak. Receiver operating characteristic curves and regression analyses were used to evaluate the prognostic value of elongation and correct for hostility factors. Results: Immediate postoperative straightening was followed by progressive aortic elongation and increasing tortuosity, whereas Euclidean iliac lengths remained stable. In adjusted models, aortic centerline elongation per mm predicted type 1A/1B endoleak (P=0.023) and, when dichotomised, elongation ≥11 mm was associated with higher odds of any endoleak (OR 2.74, 95%CI 1.34-5.58) and type 1A/1B endoleak (OR 3.77, 95%CI 1.42-10.00). Addition of elongation improved model AUC by ≤0.02. Elongation was positively related to sac expansion (P<0.001). Conclusions: Longitudinal aortic centerline elongation and tortuosity progress during follow-up and independently precede type 1 endoleak and sac enlargement. Routine morphometric surveillance may enable earlier identification of patients at risk.