Hemorrhagic Event in Moyamoya Patients Could be Prevented with Indirect Cerebral Revascularization? Massage from the Bench

초록

Introduction: Hemorrhagic events in moyamoya patients could be characterized by bleeding from the fragile vessel induced by chronic cerebral hypoperfusion. There is much debate about the possibility of prevention of a hemorrhagic event with indirect revascularization. We did this study to elucidate what happened at the molecular level in the ischemic area after revascularization in terms of angiogenetic factors. Methods: The cerebral hypoperfusion model has been made with occlusion of bilateral internal carotid artery (2ICAO) at a more superior level than the point of origin of the pterygopalatine artery. Male SD rats (6 weeks) were grouped into three groups (Sham, 2ICAO: bilateral internal carotid occlusion, and 2ICAO+EMAS: bilateral internal carotid occlusion followed by encephalo-myo-synangiogenesis). The animals were sacrificed after 3 weeks of post-2ICAO, and then analyzed by immuno-histochemistry and Western blot for angiogenesis. Results: The PECAM1-positive vessel density increased significantly in the 2ICAO+EMAS group compared with the sham group 3 weeks after ICA occlusion. The PECAM1-positive vessel numbers decreased in the 2ICAO group and increased in the 2ICAO+EMAS group compared with the sham group. More interestingly, the expression of pro-angiogenic factors increased in the 2ICAO group compared with the sham group, while it decreased significantly in the 2ICAO+EMAS group. Conclusions: Indirect revascularization could promote neovascularization from vascularized flap such as temporal muscle and restore the hypoxic condition. Also, it could modulate expression of pro-angiogenic factors such as HIF-1, VEGF, and Ang-1,2 in ischemic area. These data suggest that indirect revascularization could prevent hemorrhagic event by inhibiting formation of very fragile vessel.