摘要： 目的 探讨通过乙状窦后入路手术中较易显露的颅骨表面解剖标志建立的坐标系在关键孔定位中的应用价值。方法 回顾分析2019年1月至2020年1月山东省临沂市中心医院影像科数据库内80例三叉神经痛或面肌痉挛患者计160侧颅骨薄层CT资料并三维成像，以二腹肌沟顶点（A点）、颞鳞与顶乳缝交点（B点）和星点（C点）构建影像学模型并探寻关键孔定位规律。再选择2020年5月至2022年5月在我院行乙状窦后入路微血管减压术的60例患者（三叉神经痛33例、面肌痉挛25例、舌咽神经痛2例），随机分为重建组、非重建组和对照组（各20例），重建组术中构建坐标系后，以术前影像学模型模拟的关键孔圆心定位关建孔；非重建组术中构建坐标系后，根据影像学模型关键孔定位规律定位关键孔圆心；对照组术中不构建坐标系，以星点为关键孔圆心定位关建孔，均常规行微血管减压术。术后24 h内构建影像学模型，测量骨窗面积、骨质缺损面积、术中实际关键孔圆心（R₀点）与理想关键孔圆心（R点）的距离（D值）。结果 基于影像科数据库内80例患者（160侧）的影像学模型显示，以二腹肌沟顶点（A点）、颞鳞与顶乳缝交点（B点）和星点（C点）建立坐标系后，R点坐标平均为［（4.60 ±3.89）mm，（4.88 ±4.14）mm］，近似坐标点为（5 mm，5 mm）；颞鳞与顶乳缝交点-二腹肌沟顶点连线与乙状窦沟上曲段重合率为93.13%（149/160）、与乙状窦沟上曲段和垂直段重合率为71.25%（114/160），颞鳞与顶乳缝交点-星点连线与横窦沟重合率为95.63%（153/160）。基于60例手术患者手术前后影像学模型和术中所见显示，3组患者骨窗面积、骨质缺损面积、D值差异均具有统计学意义（P=0.000），重建组和非重建组骨窗面积、骨质缺损面积和D值小于对照组（均P < 0.01），重建组骨窗面积（P=0.009）和D值（P=0.000）亦小于非重建组。结论 在不具备术前颅骨三维CT重建的条件下，以二腹肌沟顶点（A点）、颞鳞与顶乳缝交点（B点）和星点（C点）建立坐标系，以坐标点（5 mm，5 mm）为关键孔圆心形成骨窗，可以较好定位关键孔。

关键词: 颅骨, 解剖标志, 微血管减压术, 计算机,模拟, 神经解剖学

Abstract: Objective To explore the application value of skull surface markers which are easy to be exposed in the operation of retrosigmoid sinus approach to establish coordinate system in the location of key holes. Methods The thin slice CT of 80 patients with trigeminal neuralgia or hemifacial spasm from the image database of Linyi Central Hospital of Shandong Province from January 2019 to January 2020 were selected for three-dimensional (3D) imaging. The coordinate system was constructed by the vertex of digastric sulci (point A), the intersection of temporal scale and parietal lacustrine suture (point B) and star point (point C). A total of 60 patients who were hospitalized in our hospital from May 2020 to May 2022 and required retrosigmoid sinus approach for microvascular decompression (MVD) were selected and randomly divided into reconstruction group, non-reconstruction group and control group, with 20 cases in each group. In reconstruction group, after the construction of the coordinate system during the surgery, the center of key hole in 3D skull model constructed before surgery was used to locate the location. In non-reconstructed group, after the intraoperative construction of coordinate system, the key hole positioning law of the imaging model was used as the center of the key hole. In control group, no coordinate system was established during the operation, and the center of the key hole was taken as the star point. After the center of the key hole was determined, MVD was performed routinely in all groups. The 3D skull model was constructed after surgery, and bone window area, bone defect area, the actual center of key hole (R₀) and the center of ideal key hole (R, D value) were measured. Results The results of the imaging model showed the average coordinates of point R were[(4.60 ±3.89) mm, (4.88 ±4.14) mm], and the approximate coordinates were (5 mm, 5 mm) after the establishment of the coordinate system with the vertex of digastric sulcus (point A), the intersection of temporal scale and parietal lacustrine suture (point B) and star point (point C). The coincidence rate between the intersection of temporal scale and parietal lacustrine suture and the transverse sinus groove was 95.63% (153/160), and the coincidence rate between the intersection of temporal scale and parietal lacustrine suture and the vertex of digastric sulcus and the superior curve of sigmoid sinus groove was 93.13% (149/160). The coincidence rate between the intersection of temporal scale and parietal lacustrine suture and the vertex line of digastric sulcus and the superior and vertical segment of sigmoid sulcus was 71.25% (114/160). The results showed the bone window area, bone defect area and D value were significantly different among 3 groups (P=0.000, for all), and the bone window area, bone defect area and D value in reconstruction group and non-reconstruction group were all smaller than those in control group (P < 0.01, for all). Bone window area (P=0.009) and D value (P=0.000) in reconstructed group were also smaller than those in non-reconstructed group. Conclusions In the absence of preoperative CT 3D reconstruction of the skull, a coordinate system was established with the vertex of the digastric sulcus (point A), the intersection of temporal scale and parietal lacustrine suture (point B) and star point (point C), and a bone window was formed with the coordinate point (5 mm, 5 mm) as the center of the key hole to better locate the location of the key hole.

Key words: Skull, Anatomic landmarks, Microvascular decompression surgery, Computers, analog, Neuroanatomy