摘要目的 模拟神经内镜经小脑幕上下人路对第三脑室后部解剖结构及显露范围进行解剖学研究,进而为神经内镜下治疗该区域病变提供解剖学依据.方法 头颅标本5具(10侧),模拟神经内镜经幕下小脑上正中入路、旁正中入路、经枕下幕上入路对第三脑室后部解剖结构进行观察和测量,比较不同入路下的显露情况.结果 (1)解剖结构的测量:小脑桥静脉为(3.6±0.6)根;Galen静脉直径为(5.6 ±0.6)mm,根部距窦汇(50.8±3.7) mm;缰联合距窦汇(74.4 ±6.7)mm;前联合至窦汇的平均距离为(107.2±7.3) mm.(2)不同入路的对比:神经内镜经幕下小脑上正中入路、旁正中入路、经枕下幕上人路下松果体的显露范围大致相等,平均为(19.6 ±2.8)mm2;胼胝体压部的平均显露面积分别为(55.2 ±7.9)mm2、(34.7±7.9)mm2、(44.9±5.9) mm2;侧丘的平均显露面积分别为(153.8±13.4) mm2、(177.5±24.0)mm2、(197.6±19.8)mm2,差异均有统计学意义(均P ＜0.05).结论 神经内镜经小脑幕上下入路治疗第三脑室后部病变安全、可行.术前应根据病变的类型、大小、位置以及与周围结构的关系等选择合适的手术入路.

abstractsObjective To conduct anatomic study of structures and exposure of the posterior third ventricle by simulating superior and inferior transtentorial approach with endoscope and to provide anatomical basis for treatment involving this area with endoscope.Methods Five formalin-fixed cadaver heads (10 sides) were dissected bilaterally.To observe and measure anatomical structures of the posterior third ventricle by endoscopic infratentorial-supracerebellar (midline or paramedian) approach and occipital-tentorial approach with comparison of exposure using different surgical approaches.Results (1) Measurement of anatomical structures:Average number of bridging veins of the cerebellum was 3.6 ± 0.6.The diameter of the vein of Galen was 5.6 ± 0.6 ram.The distance from Habenular commissure to confluence of sinuses was 74.4 ± 6.7 mm and the distance from anterior commissure to confluence of sinuses was 107.2 ± 7.3 ram.(2) Comparison of different surgical approaches:The exposed area of pineal glands was 19.6 ±2.8 mm2,which was almost the same to that in operations through infratentorial-supracerebellar (midline or paramedian) approach and occipital-tentorial approach.The average of exposed area in splenium of corpus callosum was 55.2 ±7.9 mm2,34.7 ±7.9 mm2 and 44.9 ±5.9 mm2,respectively,and in ipsilateral superior colliculus was 153.8 ± 13.4 mm2,177.5 ± 24.0 mm2 and 197.6 ± 19.8 mm2,respectively.Both had statistically significant difference (all P ＜ 0.05).Conclusions Endoscopic superior and inferior transtentorial approach seems feasible and safe for removal of tumors in the posterior third ventricle.Selection of surgical approaches should be based on the tumor type,size,location and its relationship to the surrounding structures.