基于解剖学研究的枕下乙状窦后入路精准开颅技术探讨

Investigation on the method of precise localization in the craniotomy of suboccipital retrosigmoid approach based on the anatomical study

目的探索应用颅骨表面解剖标志指导枕下乙状窦后入路安全、精准、快速开颅技术。方法从2016年4月至2019年6月选取15具颅骨标本和8具尸头标本,定位颅骨标本解剖标志点:二腹肌沟顶点、乳突尖、星点及关键点(横窦-乙状窦移形处相对应颅外标志点),研究颅骨解剖标志点间的关系,制定开颅技术,并将该开颅技术应用于28例患者,通过评估相关指标,评价此开颅技术的可行性。结果(1)解剖研究及尸头验证:关键点与二腹肌沟顶点距离左侧为(16.79±3.50) mm、右侧为(14.82±2.96) mm,关键点与星点距离左侧为(19.53±3.84) mm、右侧为(22.59±4.08) mm,关键点与乳突尖的距离左侧为(33.98±3.87) mm、右侧为(32.78±3.29) mm,关键点与星点的距离左、右侧间差异有统计学意义(P=0.020)。将开颅技术应用于8例尸头标本,均未出现静脉窦损伤。(2)临床应用:28例患者进行开颅技术验证,23例横窦乙状窦暴露充分,无钻孔所致静脉窦破损,平均开颅时间为(23.1±2.2) min,骨瓣1.8 cm×2.0cm,骨窗直径2.0~2.5 cm,术中骨瓣复位。结论以眶下缘与外耳道上缘连线为基线,过二腹肌沟顶点作基线的垂直线,在垂直线上定位二腹肌沟顶点上方14 mm(左侧)/12 mm(右侧)的点,确定此处为钻孔骨孔中心点并形成骨孔,可以获得满意的术区显露,避免静脉窦的损伤,为临床安全、精准、快速开颅提供依据。

Objective To explore the method of precise localization in the craniotomy of suboccipital retrosigmoid approach based on the skull anatomical landmarks in order to provide the evidence for safe, accurate and fast clinical craniotomy. Methods From April 2016 to June 2019, 15 skull specimens and 8 cadaver head specimens were applied. The anatomical landmarks as followed were identfied on skull specimens: the top point of the digastric groove, mastoidale, asterion and keypoint(corresponding extracracranial point of the transverse-sigmoid sinus junction). The relationship between anatomical markers of skull specimens was studied to develop the craniotomy of suboccipital retrosigmoid approach. 28 patients were performed the craniotomy in the clinical surgery by evaluating relevant indicators to evaluate the feastibility of craniotomy. Results(1) Anatomical study and cadaveric test: the distance from keypoint to the top point of the digastric groove was(16.79 ± 3.50) mm(left)and(14.82 ± 2.96) mm(right);the distance from keypoint to asterion was(19.53 ± 3.84) mm(left)and(22.59 ± 4.08) mm(right);the distance from keypoint to mastoidale was(33.98±3.87) mm(left) and(32.78±3.29) mm(right). The value of the left distance from keypoint to asterion was smaller than the right side(P=0.020). 8 cadaveric heads specimens were verified the simulate craniotomy of suboccipital retrosigmoid approach. No venous sinus injury was found.(2)Clinical application: 28 patients were performed the craniotomy of suboccipital retrosigmoid approach.Operative area was exposed clearly in 23 patients. No venous sinus rupture occurred. The average craniotomy time was(23.1±2.2) min. The size of bone flap was 1.8 cm×2.0 cm. The diameter of bone window was 2.0~2.5 cm. Bone flap was replaced during the operation. Conclusions In order to precisely locate the keypoint in the craniotomy of suboccipital retrosigmoid approach, the center of the burr hole can be exact oriented according to 14 mm(left)/12 mm(right) vertically above the top point of mastoid groove based on the line between the supraorbital margin and the upper edge of the external auditory canal. This method can insure safe, accurate and rapid craniotomy with a good vision and avoiding the injury of venous sinus.