502 - Preoperative Aneurysm Characteristics That Predict Need for Repeat Endoleak Procedure Following Type II Endoleak Embolization

Purpose: Endoleaks are the most common complication following endovascular abdominal aortic aneurysm repair (EVAR). The purpose of this study was to evaluate the preoperative aneurysm characteristics associated with need for repeat endoleak procedure following type II endoleak embolization.

Materials and Methods: Single center retrospective review of 50 patients who underwent type II endoleak embolization procedures from August 5, 2011, to January 17, 2025. Clinical, preoperative imaging characteristics including suprarenal neck angle, coronal and sagittal aneurysm neck angles, maximum aneurysm diameter, and procedural data were recorded. True aortic neck and suprarenal angles were calculated from the sagittal and coronal 2D reconstructed images using the paired angle formula {1}. Multivariate logistic regression analysis was performed after univariate analysis to determine independent predictors of need for repeat endoleak procedure.

Results: 50 patients underwent type II endoleak embolization procedures, 17 (34%) of which required repeat endovascular endoleak procedure. There was no difference in age (p = 0.48), gender (p > 0.99), embolization technique (transarterial vs. transcaval vs. translumbar, p = 0.66), maximum abdominal aortic aneurysm diameter (5.73 ± 1.01 vs. 5.70 ± 0.92 cm; p = 0.91), mean aneurysm neck diameter (2.38 ± 0.51 vs. 2.25 ± 0.34 cm; p = 0.29) or length (2.47 ± 1.31 vs. 2.54 ±1.63 cm; p = 0.88) in patients who required a repeat endoleak procedure versus those who did not. Suprarenal neck angle and true aortic neck angle were significantly increased in patients who required a repeat endoleak procedure versus those who did not (34.18° ± 13.30 vs. 17.43° ± 11.20; p < 0.0001 and 60.12° ± 23.79 versus 43.90° ± 17.31; p = 0.008, respectively). In multivariate logistic regression analysis, only suprarenal neck angle retained statistical significance (OR 1.1, 95% CI 1.04-1.18; p = 0.004). ROC curve analysis of suprarenal neck angle demonstrated an area under the curve (AUC) of 0.84 (95% CI 0.72-0.96; p < 0.0001). A suprarenal neck angle cutoff value of 23.3° was associated with a sensitivity of 82.4% and specificity of 81.8% in predicting need for repeat endoleak procedure.

Conclusion: True aortic neck and suprarenal neck angles are associated with need for repeat endoleak procedure following type II endoleak embolization. There may be a subset of patients with an imaging occult endoleak who continue to have sac growth following type II endoleak embolization procedures if their preoperative aneurysm neck has the characteristics described above.