To provide anatomic basis for the retrosigmoid supra-tentorium to infra-tentorium keyhole approach and to explore the feasibility, 60 skulls were observed and measured to demonstrate the position relations among related bony landmarks, 12 cadaveric heads were dissected and measured for localization of the keyhole and the incision through tentorium. For giving the angle and depth for endoscopic approach, 40 adult volunteers were performed head MRI scan and the pictures were measured and analyzed. The surface projection of sigmoid and transverse sinus can be positioned by mastoidale, external occipital protuberance, and anterior end of parietomastoid suture (AEPMS) on body. There is a safe trigone of cerebellar tentorium (STCT) among inner edge of upper curve of sigmoid sinus, entrance of tentorial sinus/vein and midpoint of posterior edge of temporal arcuate eminence. 15 mm superior to the midpoint between asterion and AEPMS can be recognized as the central point of the keyhole. Magnetic resonance imaging pictures show there is potential subarachnoid space for endoscopic approach from the indicated keyhole to pontocerebellar trigone. This study demonstrated endoscopy can arrive at pontocerebellar trigone through the STCT and the keyhole supra-tentorium to infra-tentorium endoscope approach is feasible in anatomy and will contribute to excise lesions involving both supra- and infra-tentorial structures.
*Department of Human Anatomy, Histology and Embryology, Faculty of Basic Medical Sciences
†Department of Neurosurgery, The First Affiliated Hospital
‡Department of Medical Imaging, The First Affiliated Hospital
§Department of Pathology and Pathophysiology, Faculty of Basic Medical Sciences
||Department of the Head and Neck Surgery, The Third Affiliate Hospital
¶School of Rehabilitation, Kunming Medical University, Kunming, China.
Address correspondence and reprint requests to Shaochun Chen, Department of Human Anatomy, Histology and Embryology, Faculty of Basic Medical Sciences, Kunming Medical University, 1168 West Chunrong Road, Kunming, PR China 650500; E-mail: firstname.lastname@example.org
Received 27 November, 2018
Accepted 26 December, 2018
This work was supported by grants from the National Natural Science Foundation of China (No. 81260195 and 81302362) and the Special-Combined- Funds between the Department of Science-technology of Yunnan Province and Kunming Medical University (2018FE001).
The authors report no conflicts of interest.