Suboccipital burr holes and craniectomies

Area of Science:

• Neurosurgery
• Anatomy
• Surgical Navigation

Background:

• The transverse and sigmoid sinuses are critical venous structures in the posterior cranial fossa.
• Accurate localization of these sinuses is essential for safe surgical approaches to the infratentorial region, particularly the cerebellopontine angle (CPA).
• Existing external landmarks for surgical planning of lateral infratentorial suboccipital approaches require further refinement.

Purpose of the Study:

• To precisely delineate the external cranial projection of the transverse and sigmoid sinuses.
• To establish reliable, systematized burr hole sites for lateral infratentorial suboccipital craniectomy.
• To correlate these burr hole sites with external cranial landmarks, including the lambdoid, occipitomastoid, and parietomastoid sutures.

Main Methods:

• Analysis of 50 paired temporoparietooccipital regions from 25 adult human skulls.
• External sinus margins were outlined using internal-to-external perforations.
• Evaluation of 1-cm diameter burr hole placements at strategic sites for supratentorial, trans-sinus, and infratentorial components.

Main Results:

• The asterion and the midpoint of the inion-asterion line correlate with the inferior transverse sinus.
• The transition of the transverse and sigmoid sinuses is located 1 cm anterior to the asterion, crossing the parietomastoid suture.
• Specific burr hole sites were identified relative to sutures and landmarks for optimal exposure of sinus segments and the CPA.

Conclusions:

• The study provides an accurate estimation of the external cranial projection of the transverse and sigmoid sinuses.
• Identified burr hole sites, including the asterion and occipitomastoid suture, serve as effective starting points for suboccipital craniectomy.
• These landmarks facilitate precise surgical access to the superior and inferior aspects of the cerebellopontine angle (CPA).