Post-interventional microembolism: cortical border zone is a preferential site for ischemia.

BACKGROUND

Previous diffusion-weighted MRI (DWI) studies have indicated that 10-40% of patients have silent embolism during neurointerventional procedures. However, lesion patterns of the embolisms have not been adequately investigated.

METHODS

DWI was taken within 7 days before and 48 h after cerebral angioplasty and stent procedures. New lesions on the follow-up DWI were analyzed in the non-treated arterial territories. Based on the arterial territories, supratentorial lesions were classified into cortical lesions and subcortical lesions. Cortical lesions were subdivided into cortical border zone and cortical proper lesions. Subcortical lesions were divided into deep perforator and internal border zone lesions. Infratentorial lesions were divided into brainstem and cerebellar lesions.

RESULTS

72 patients were included in this study. There were 223 new DWI lesions (1-23 lesions) in the non-treated arterial territories of 37 patients. There were 154 cortical lesions, 45 cerebellar lesions, 21 subcortical lesions and 3 brainstem lesions. Analysis of the distribution pattern of cortical lesions showed that 88 of 154 lesions were located at the cortical border zone. Of the subcortical lesions, 13 of 21 lesions were located at the internal border zone area, within the corona radiata and centrum ovale. Only 4 lesions were located at the deep perforator territory. Infratentorial lesions were mostly located at the cerebellar hemisphere (45/48). Most lesions were tiny infarcts (<5 mm diameter); 7 of 223 lesions were >10 mm in diameter.

CONCLUSIONS

Interventional-angiography-related microembolisms mostly lodge in the cerebral cortical border zone area and cerebellar hemisphere. Microembolisms to the deep perforating artery territory are distinctly rare.