目的 通过解剖学研究，探索顶枕部注入上矢状窦桥静脉的分布规律，比较各种至侧脑室三角区的经纵裂入路在外侧方向暴露范围，为临床设计、选择和改良手术入路提供解剖学依据。 方法 取4%甲醛固定、乳胶灌注动静脉血管的国人头颅标本5具，开颅并保留人字缝作为测量标志，观察后囟点前后桥静脉的分布情况，总结顶枕部桥静脉在后囟点前、后的分布规律。取4%甲醛固定、乳胶灌注的国人头颅标本5具，导航辅助下模拟同侧和对侧的经胼胝体、经扣带回、经楔前叶入路共6种手术入路的手术路径，以导航棒模拟手术视线，以导航棒与正中矢状面所成的角度代表手术入路在外侧方向的暴露范围，记录、计算各入路在外侧方向的暴露范围，并相互比较。 结果 没有桥静脉于后囟点和窦汇之间注入上矢状窦。在后囟点前方距离为s（s代表后囟点到窦汇的距离）的范围内注入上矢状窦的桥静脉，平均每个标本左侧有（1.4±0.5）条，右侧（1.6±0.5）条，双侧共（3.0±0.6）条。在同侧入路中，外侧方向的暴露范围经胼胝体入路＜经扣带回入路＜经楔前叶入路；对侧入路与同侧入路相同，暴露范围经胼胝体入路＜经扣带回入路＜经楔前叶入路。在切开脑组织位置相同的同侧和对侧入路中，外侧方向暴露范围同侧入路＜对侧入路。所有比较结果差异均具有统计学意义。 结论 顶枕部桥静脉集中分布在后囟点之前，后纵裂入路采用人字缝后方开颅较其前方更为安全。在经纵裂入路中，向外侧方向的暴露，经楔前叶入路优于经扣带回入路、优于经胼胝体入路，对侧入路优于同侧入路；对侧入路有利于保证导航准确性。对侧后纵裂经大脑镰经楔前叶（CITT）入路在功能保护、增加外侧方向暴露、保证导航准确性等方面有一定优势。

Objective To study the distributing pattern of bridging veins that drain into superior sagittal sinus in the parieto-occipital region, to compare the exposure range of all the interhemispheric approaches targeted at the trigone and to provide anatomical basis for designing and selecting approaches in clinical practice. Methods Craniotomies preserving the lambdoid suture were performed on 5 formalin-fixed and silicone-perfused cadaveric heads. In each specimen, the distance between the posterior fontanelle and torcular was measured, the number and location of bridging veins on either side of the midline were recorded, and the distance between the points where bridging veins joined the superior sagittal sinus and the posterior fontanelle was measured and recorded. With the help of navigation, different types of interhemispheric approaches were demonstrated in 5 formalin-fixed and silicone-perfused cadaveric head. The navigation bar was used to represent the visual line in surgical procedure. The maximum exposure of each interhemispheric approach was calculated and compared. Results The mean number of bridging veins joining the superior sagittal sinus before the posterior fontanelle and within the distance equal to that between the posterior fontanelle and torcular was 1.4+0.5 on the left, 1.6+0.5 on the right, and 3.0+0.6 on both sides. Compared with the homolateral approaches, the contralateral approaches provided a better lateral exposure. For the position of the cortical or callosal insision, those with a shorter distance to the border between the medial and lateral surface of the parietooccipital lobe had a better lateral exposure. All comparisons were of statistical significance. Conclusion The bridging veins in the parieto-occipital region tend to join the superior sagittal sinus before the posterior fontanelle, therefore it is safer to perform craniotomy behind the lambdoidal suture rather than behind the lambdoidal suture. Among the interhemispheric which approaches targeted at the trigone of the lateral ventricle, the contralateral approaches provide a better exposure in the lateral direction; those with a shorter distance to the border between the medial and lateral surface of the parietooccipital lobe provide a better lateral exposure.