Pathway plaques and diffusion-weighted lesion analysis after endovascular treatment of unruptured intracranial aneurysms: a prospective study

Objectives: To evaluate the prevalence and predictors of ischemic lesions on thin–slice DWI (2 mm) in endovascular treatments for unruptured intracranial aneurysms (UIA), particularly explore the potential relationship with pathway plaques. Methods: Participants eligible for endovascular treatments with UIA at a national stroke center between March 2023 and August 2023 were prospectively enrolled. All participants performed thin–slice DWI (slice thickness of 2 mm) before and after procedures. Three-dimensional joint intra-and extracranial vessel wall MRI (3D-vwMRI, voxel size 0.6 × 0.6 × 0.6 mm³) was scheduled to evaluate the pathway plaques for all participants. The DWI-positive numbers were ordered and divided into four equal parts, with each quartile representing 25% of the data set. Results: A total of 106 participants were included. Overall, none of the participants exhibited preoperative DWI-positive lesions. Following the intervention, 93.4% (99/106) of participants exhibited new DWI-positive lesions on postoperative MRI, including 5.7% (6/106) with symptomatic ischemic stroke. Compared with the lowest quartile of ischemic lesions, the highest quartile was associated with increased odds of the presence of plaque (OR = 9.4, 95% CI: 2.0–45.4; p = 0.005). The history of previous stroke (OR = 4.6, 95% CI: 1.6–14.6; p = 0.007) and the presence of plaque in the pathway (OR = 3.4, 95% CI: 1.6–7.7; p = 0.002) were identified as independent predictors of higher quartiles of DWI-positive numbers. Conclusions: As revealed by thin-slice DWI, ischemic lesions related to the endovascular treatments for UIA occurred more frequently than anticipated. A history of the previous stroke and the pathway plaques were independent predictors of higher quartiles of DWI-positive numbers. Key Points: Question Previous studies using conventional MRI may underestimate DWI-positive lesions. The procedural risk of UIA coexisting with atherosclerotic plaques is still unclear. Findings Thin-slice DWI showed ischemic lesions occurred frequently (93.4%). Three-dimensional-intra-and extracranial Vessel Wall MRI revealed a positive correlation between pathway plaques and DWI lesions. Clinical relevance Neuro-interventionalists should exercise caution when managing patients with a history of previous stroke in the presence of plaques in the treatment pathway. More vigilant pre-procedural imaging should be considered to assess unstable plaque in high-risk patients.