Development and validation of a nomogram to predict the risk of type II endoleak after endovascular aneurysm repair.

OBJECTIVE

Type II endoleak (T2EL) is the most common complication following endovascular aneurysm repair (EVAR) of abdominal aortic aneurysms (AAA). T2EL may lead to aneurysm sac expansion and rupture. Identifying high-risk patients is crucial for prophylaxis and early intervention.

METHODS

This single-center retrospective study included 332 patients who underwent EVAR for infrarenal AAA. Demographic, clinical, anatomical, and medication-related data were collected. A nomogram was developed based on significant predictors. Its performance was assessed by receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA).

RESULTS

T2EL occurred in 70 (21.08%) of 332 patients. Multivariate logistic regression revealed six independent predictors: age, smoking status, intraluminal thrombus (ILT), number of patent lumbar arteries (LA), inferior mesenteric artery (IMA) diameter, and IMA patency. The nomogram demonstrated excellent calibration and strong predictive ability, with an area under the curve (AUC) of 0.806 (training set) and 0.758 (validation set). DCA showed clinical benefit across threshold probabilities of 1%-66% and 79%-92% in the training set, and 1%-84% in the validation set.

CONCLUSION

The proposed nomogram effectively integrates clinical and anatomical factors to assess the risk of T2EL after EVAR. It may help identify patients requiring intensified surveillance or early interventions to mitigate complications. Further multicenter, prospective studies are needed to validate the nomogram's applicability.