Transdural Collateral Circulation Indicates Cerebral Ischemia in Moyamoya Disease

Moyamoya disease (MMD) is an idiopathic occlusive cerebrovascular disorder. The development of collateral circulation originates from the dural and pial collaterals. Currently, the clinical significance of transdural collateral in MMD has not been established. We sought to study the relationship between transdural collateral circulation and the side of relative cerebral ischemia in MMD.

Data from MMD patients were collected at Xiangya Hospital from January 2016 to April 2022. A collateral circulation grading system with scores was established, the dominant side of transdural collateral with a higher point. Cerebral perfusion was used to identify the side of relative cerebral ischemia.

A total of 102 patients were recruited. Results of digital subtraction angiography showed that 74 (72.5%) patients had transdural collaterals. The transdural collaterals were more common in patients with infarctions than in those with headaches or transient ischemic attacks (P = 0.0074). The dominant side for the formation of transdural collateral circulation was more easily found at the side of relative cerebral ischemia (P < 0.0001). Additionally, the side of the brain with a higher score of transdural collaterals was more likely to experience relative cerebral ischemia (P < 0.0001). There was no significant difference in the formation of transdural collateral circulation between ischemic and hemorrhagic MMD patients.

Transdural collateral circulation was common in MMD patients. The transdural collaterals were associated with the occurrence of infarction. Transdural collaterals were well established on the cerebral ischemic side, which indicated higher ischemic levels in the ipsilateral than contralateral side.