Related Experiment Video
Updated: Jan 30, 2026

Endoscopic Approach for Colloid Cyst Resection
Published on: May 23, 2025
Endoscope-assisted retrosigmoid keyhole approach for cerebellopontine angle: cadaveric study
1Department of Otolaryngology-Head and Neck Surgery, Anhui Provincial Hospital , Hefei, Anhui Province , China.
Conclusion:
A 20 mm hole made backwards from the midpoint of the asterion to the mastoid process is suitable for a retrosigmoid keyhole approach with the aid of an endoscope. The endoscope-assisted retrosigmoid keyhole approach can be considered an effective and safe method for removal of vestibular schwannoma.
Objective:
To investigate the feasibility of the endoscope-assisted retrosigmoid keyhole approach for exposing the cerebellopontine angle (CPA) and internal auditory canal (IAC).
Methods:
With the aid of an endoscope, we simulated surgical procedures in 30 sides of 15 formalin-fixed cadaver heads.
Results:
(1) For 24 (80%) sides, the midpoint of the top notch to the mastoid process was in the anterior edge of the sigmoid sinus; for 27 sides (90%) the midpoint of the asterion to the mastoid process was in the posterior edge of the sigmoid sinus. (2) The IAC and CPA were exposed by the retrosigmoid keyhole approach with the aid of the endoscope.
Related Concept Videos
Endoscopic Studies II: Thoracocentesis
Description
Excess pleural fluid or air may accumulate in some respiratory disorders in the thoracic cavity. To treat pleural effusion, a physician conducts thoracentesis by carefully piercing the chest wall and entering...
Endoscopic Studies I: Bronchoscopy and Thoracoscopy
Bronchoscopy
Description
Bronchoscopy is a procedure that involves direct visualization of the larynx, trachea, and bronchi for diagnostic and therapeutic purposes. A flexible fiber optic or rigid bronchoscope is used to carry out the procedure. The fiber-optic bronchoscope is more frequently used due...
Contact Angle
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
Open Angle Glaucoma: Treatment
Drugs such as carbonic anhydrase inhibitors, α2- and...
Angle of Twist: Problem Solving
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast,...

