Predicting Persistent Aneurysm Filling After Pipeline Embolization Device Treatment in Patients with Intracranial Aneurysm: Development and External Validation of a Nomogram Model.

The pipeline embolization device (PED) is an effective endovascular treatment modality for intracranial aneurysm (IA), but nearly one-fifth of IAs treated with a PED remain persistently filling at 1-year angiography follow-up. Developing a nomogram to predict persistent aneurysm filling after PED treatment can help neurointerventionalists identify aneurysms with incomplete occlusion and change their treatment strategies. This retrospective study included patients with IA treated with a PED from three institutions between April 2016 and April 2022, assigned to a derivation or validation cohort. Multivariate logistic regression analysis was used to identify predictors and develop a nomogram to predict persistent aneurysm filling after PED treatment in the derivation cohort. Predictive accuracy and clinical benefits of the nomogram were assessed using area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA). In total, 1006 patients with IA were included, 786 in the derivation cohort and 220 in the validation cohort. Over mean follow-up time 18.36 ± 8.58 months, 142 (14.1%) patients developed persistent aneurysm filling after PED treatment, 110 (14.0%) in the derivation cohort and 32 (14.5%) in the validation cohort. In multivariate logistic regression analysis, we developed a nomogram incorporating five predictors: aneurysms located in the basilar artery, dissecting aneurysms, maximum diameter, aneurysms with incorporated branches, and PED plus coiling. AUCs of the nomogram were 0.810 (95% confidence interval [CI], 0.765-0.856) in the derivation cohort and 0.840 (95% CI, 0.754-0.925) in the validation cohort. Calibration curve and DCA analysis demonstrated the utility and clinical application value of this nomogram. This nomogram provides individualized prediction of persistent aneurysm filling after PED treatment for patients with IA, representing a practical approach to effectiveness evaluation. This tool can help neurointerventionalists to identify aneurysms with incomplete occlusion and change their treatment strategy.