Abstract：
BACKGROUND: Supratentorial craniotomy represents the upper part of the combined trans-tentorial or the supra-infratentorial presigmoid approach. In this study, we provide qualitative and quantitative analyses for the supratentorial extension of the presigmoid retrolabyrinthine suprameatal approach (PRSA).
METHODS: The infratentorial PRSA followed by the supratentorial extension craniotomy with dividing and removal of the tentorial strip were performed on both sides of 5 injected human cadaver heads (n = 10 sides). Quantitative analysis was performed for the surface area gained (surgical accessibility) by adding the supratentorial craniotomy. Qualitative analysis was performed for the parts of the brainstem, cranial nerves, and vascular structures that became accessible by adding the supratentorial craniotomy. The anatomical obstacles encountered in the added operative corridor were analyzed.
RESULTS: The supratentorial extension of PRSA provides an increase in surgical accessibility of 102.65% as compared to the PRSA standalone. The mean surface area of the exposed brainstem is 197.98 (standard deviation: 76.222) and 401.209 (standard deviation: 123.96) for the infratentorial and the combined supra-infratentorial presigmoid approach, respectively. Exposure for parts of III, IV, and V cranial nerves is added after the extension, and the surface area of the outer craniotomy defect has increased by 60.32%. Parts of the basilar, anterior inferior cerebellar, and superior cerebellar arteries are accessible after the supratentorial extension.
CONCLUSIONS: The supratentorial extension of PRSA allows access to the supra-trigeminal area of the pons and the lower part of the midbrain. Considering this surgical accessibility and exposure significantly assists in planning such complex approaches while targeting central skull base lesions.
METHODS: The infratentorial PRSA followed by the supratentorial extension craniotomy with dividing and removal of the tentorial strip were performed on both sides of 5 injected human cadaver heads (n = 10 sides). Quantitative analysis was performed for the surface area gained (surgical accessibility) by adding the supratentorial craniotomy. Qualitative analysis was performed for the parts of the brainstem, cranial nerves, and vascular structures that became accessible by adding the supratentorial craniotomy. The anatomical obstacles encountered in the added operative corridor were analyzed.
RESULTS: The supratentorial extension of PRSA provides an increase in surgical accessibility of 102.65% as compared to the PRSA standalone. The mean surface area of the exposed brainstem is 197.98 (standard deviation: 76.222) and 401.209 (standard deviation: 123.96) for the infratentorial and the combined supra-infratentorial presigmoid approach, respectively. Exposure for parts of III, IV, and V cranial nerves is added after the extension, and the surface area of the outer craniotomy defect has increased by 60.32%. Parts of the basilar, anterior inferior cerebellar, and superior cerebellar arteries are accessible after the supratentorial extension.
CONCLUSIONS: The supratentorial extension of PRSA allows access to the supra-trigeminal area of the pons and the lower part of the midbrain. Considering this surgical accessibility and exposure significantly assists in planning such complex approaches while targeting central skull base lesions.
摘要：
背景：幕上开颅术代表了经幕下或上幕下脑垂体联合入路的上部。在这项研究中,我们提供了定性和定量分析的胃窦后迷路入路（PRSA）的幕上扩展。
方法：在5个注射的人尸体头的两侧（n=10侧）进行了幕下PRSA，然后进行了幕上扩展开颅术，并分割和去除了小脑条。通过添加幕上开颅术对获得的表面积（手术可及性）进行定量分析。对脑干部分进行了定性分析，颅神经,和血管结构，这些血管结构通过增加幕上开颅术而变得容易进入。分析了在增加的手术走廊中遇到的解剖学障碍。
结果：与单独使用PRSA相比，PRSA的幕上延伸使手术可及性增加了102.65％。对于鼻下和联合的鼻下脑垂体方法，暴露的脑干的平均表面积为197.98（SD：76.222）和401.209（SD：123.96）。分别。III部分的暴露，IV,延伸后增加了V脑神经，开颅外侧缺损的表面积增加了60.32%。基底的一部分，小脑前下，小脑上动脉在幕上延伸后可进入。
结论：PRSA的幕上延伸允许进入脑桥的三叉神经上区域和中脑下部。考虑到这种手术的可及性和暴露性显着有助于计划这种复杂的方法，同时针对中央颅底病变。
方法：在5个注射的人尸体头的两侧（n=10侧）进行了幕下PRSA，然后进行了幕上扩展开颅术，并分割和去除了小脑条。通过添加幕上开颅术对获得的表面积（手术可及性）进行定量分析。对脑干部分进行了定性分析，颅神经,和血管结构，这些血管结构通过增加幕上开颅术而变得容易进入。分析了在增加的手术走廊中遇到的解剖学障碍。
结果：与单独使用PRSA相比，PRSA的幕上延伸使手术可及性增加了102.65％。对于鼻下和联合的鼻下脑垂体方法，暴露的脑干的平均表面积为197.98（SD：76.222）和401.209（SD：123.96）。分别。III部分的暴露，IV,延伸后增加了V脑神经，开颅外侧缺损的表面积增加了60.32%。基底的一部分，小脑前下，小脑上动脉在幕上延伸后可进入。
结论：PRSA的幕上延伸允许进入脑桥的三叉神经上区域和中脑下部。考虑到这种手术的可及性和暴露性显着有助于计划这种复杂的方法，同时针对中央颅底病变。
