脑海绵状血管畸形与动静脉畸形对放疗的不同反应

Different responses of cavernous malformations and arteriovenous malformations to radiosurgery

目的 探究脑海绵状血管畸形（CMs）与动静脉畸形（AVMs）的结构差异和对于放射外科治疗反应的不同.方法 实验样本共33例,包括放射外科治疗后的CMs 3例,放射外科治疗后的AVMs 3例,未经照射的CMs 6例,未经照射的AVMs 17例和健康对照4例.取材后立即处理,并应用光学显微镜和透射电子显微镜观察5组间的超微结构差异.结果 CMs显示管腔直径与血管壁的厚度较大而且缺乏内皮下成纤维细胞,肌成纤维细胞和平滑肌细胞.CMs放射外科治疗后形成部分蛋白质凝块（管腔的19％ ～22％）,在放射治疗后长达6年后也未出现完整的血管闭塞.AVMs观察到由纤维蛋白血栓组成永久性的血栓,使血管完整的闭塞（管腔的91％ ～ 98％）.照射诱导病灶周围的脑组织发生神经元丢失和神经原纤维变性.结论 CMs与AVMs的血管结构及细胞成分的不同导致它们对放射外科治疗的反应不同.

Objective To study different vascular structure between cavernous malformations （CMs） and arteriovenous malformations（AVMs） and different changes of CMs and AVMs after radiosurgery.Methods 33 specimens,among them three irradiated CMs,three postradiation AVMs,six nonirradiated CMs,seventeen nonirradiated AVMs,and four normal controls were processed for ultrastructural study immediately after removal.Results compared with AVMs,CMs showed a higher ratio of intraluminal diameter to vessel wall thickness and a lack of subendothelial fibroblasts,myofibroblasts and smooth muscle cells.Partial proteinaceous clots（19％-22％ of lumen） formed in CMs sinusoids after radiosurgery but complete vaso-occlusion did not occur for up to 6 years after radiosurgery.In contrast,complete vaso-occlusion（91％-98％ of lumen） by fibrin thrombi that are permanent clots was observed in AVMs vessels.Radiation-induced neuronal loss,neurofibrillary degeneration of neurons and myelin fragmentation were typical in the surrounding brain tissue of the irradiated lesions.Conclusion The different structure and cellular compositions of CMs and AVMs are likely to influence their responses to radiosurgery.