目的　通过分析个体化三维数字模型(three-dimensional digital model, 3D-DM)辅助下内镜经鼻入路对下斜坡及其相关区域解剖，探讨个体化3D-DM的应用价值。  方法　将血管灌注后的12例头颅标本行320排螺旋CT扫描得到DICOM格式图像导入3DView软件重建颅底骨质、血管，整合为3D-DM。模拟内镜经鼻入路下斜坡骨质磨除，明确并测量相关解剖标志间的距离，并行内镜解剖，对比3D-DM与实际解剖相关测量数据，计算骨质磨除的实际完成率。  结果　个体化3D-DM可模拟手术操作，与实体解剖所见一致。3D-DM测量与实际解剖相关测量间无统计学差异。个体化3D-DM可术前明确重要结构的部位、形态、走行及毗邻，可模拟下斜坡骨质磨除并定量测量。内镜经鼻入路可显示下斜坡双侧结构。髁上沟是下斜坡最重要的定位标志。磨除枕髁骨质，可增加侧方暴露。磨除颈静脉结节可暴露后组颅神经的远侧脑池部分。  结论　个体化3D-DM辅助下，内镜经鼻入路可以暴露下斜坡腹侧结构，可术前明确下斜坡的主要解剖标志及其解剖结构位置、特点和变异，为术中安全骨质磨除提供保障。

Objective　The aim of our study was to apply an customized three-dimensional digital model(3D-DM) to endoscopic endonasal approaches to analyze the bony anatomy of inferior third of the clivus, quantify preoperative bone removal, and optimize surgical planning.　Methods　Silicone dyes were respectively injected into the great vessels of the neck of 12 cadaveric specimens. Digital data acquired from 320-slices CT scan was imported to a 3DView system to form individual 3D-DM. With the 3D-DM support, an endoscopic endonasal dissection of the inferior clivus was completed under conditions that mimicked our operating suite. Bone removal of occipital condyle was quantified postoperatively by 3D-DM, which compared with the preoperative ones, to analyze physical percentage of bone excision.　Results　Customized 3D-DM was useful to de?ne the exact boundaries of the endoscopic endonasal approaches. The vision acquired by 3D-DM was consistent with the intraoperative findings. Preoperative measurement of related landmarks in 3D-DM showed no significant difference from the measurement data on cadaveric head specimens. Completion of a unilateral ventromedial condyle resection opened a wider lateral surgical corridor. The supracondylar groove was a reliable landmark for locating the hypoglossal canal. The transjugular tubercle approach was accomplished by drilling above the hypoglossal canal, and increasing of the vertical length of the lateral surgical corridor, which allowed for visualization of the distal cisternal segment of the lower cranial nerves.　Conclusions　The endonasal approach provides exposure of the brainstem in the ventromedial compartment. This 3D-DM is very effective in providing a depiction of surgical landmarks and visual feedback of the amount of bone removed.