Factors Associated with Postprocedural Diffusion-Weighted Imaging–Positive Lesions in Endovascular Treatment for Unruptured Cerebral Aneurysms

Background: In endovascular treatment for cerebral aneurysms, the appearance of asymptomatic thromboembolic lesions detected by postprocedural diffusion-weighted imaging (DWI) can be a surrogate marker for estimating the potential risk of symptomatic thromboembolism. The aim of this study was to clarify factors associated with postprocedural DWI-positive lesions in endovascular treatment for unruptured cerebral aneurysms. Methods: Patients with untreated unruptured cerebral aneurysms undergoing endovascular treatment were consecutively enrolled. Treatment techniques were classified into simple coiling, balloon-assisted coiling, stent-assisted coiling, and flow-diverter placement. Head magnetic resonance imaging was performed within 3 months before and 24 hours after the procedure to assess the appearance of DWI-positive lesions. Results: Among 376 aneurysms in 355 patients that were analyzed, 232 (61.7%) had postprocedural DWI-positive lesions. In univariate analyses, age (P = 0.001), dome size (P < 0.001), neck size (P < 0.001), treatment technique (P = 0.029), and total procedural time (P < 0.001) were significantly associated with postprocedural DWI-positive lesions. In the multiple logistic regression model, older age (odds ratio, 1.33; 95% confidence interval, 1.10–1.60; P = 0.003; per decade), flow-diverter placement (odds ratio, 4.93; 95% confidence interval, 1.33–20.92; P = 0.016; compared with simple coiling), and longer procedural time (odds ratio, 1.66; 95% confidence interval, 1.26–2.21; P < 0.001; per hour) were associated with postprocedural DWI-positive lesions. Conclusions: Older age, flow-diverter placement, and longer procedural time were associated with postprocedural DWI-positive lesions in endovascular treatment for unruptured cerebral aneurysms.