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

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.

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.

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.

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.

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.