Methods 201 cases of chronic subdural hematomas were divided into 2 groups according to the number of burr holes: single-hole group and double-hole group.

• 方法201例慢性硬膜下血肿患者按单、双颅骨钻孔分为两组,以是否须再次手术为标准,比较两者间疗效的差异。