Precise Localization in Craniotomy With a Retrosigmoid Keyhole Approach: Microsurgical Anatomy and Clinical Study

Area of Science:

• Neurosurgery
• Anatomical Landmark Localization
• Surgical Approaches

Background:

• Precise localization for craniotomy is crucial for surgical success.
• The suboccipital retrosigmoid approach requires accurate landmark identification.
• Minimizing venous sinus injury during craniotomy is a key safety concern.

Purpose of the Study:

• To explore a method for precise craniotomy localization using skull anatomical landmarks.
• To validate this method via the suboccipital retrosigmoid approach.
• To assess the safety, accuracy, and efficiency of the technique in clinical application.

Main Methods:

• Craniometric measurements were performed on dry skulls and cadaver specimens.
• A simulated craniotomy was conducted on cadaver heads using the suboccipital retrosigmoid approach.
• The burr hole center was precisely oriented 12 mm above the mastoid groove based on specific facial landmarks.

Main Results:

• The method demonstrated accurate localization for craniotomy.
• No venous sinus injuries were observed in anatomical or clinical applications.
• Clinical application in 29 patients showed clear operative field exposure and satisfactory microsurgical anatomy.
• Average craniectomy time was 27.02 ± 0.86 min with a bone window diameter of 1.7-2.9 cm.

Conclusions:

• The described method ensures safe, accurate, and rapid craniotomy.
• The technique provides good surgical vision.
• It effectively avoids injury to the venous sinus during the suboccipital retrosigmoid approach.