Anatomical position of the asterion and its underlying structure

Area of Science:

• Neurosurgery
• Anatomy
• Surgical Landmark Validation

Background:

• The asterion is traditionally used as a surface landmark for surgical access to the posterior cranial fossa dura.
• Accurate anatomical landmarks are crucial for safe and effective surgical planning and execution.

Purpose of the Study:

• To evaluate the reliability of the asterion as a landmark for the posterior fossa dura.
• To determine the anatomical relationship between the asterion and underlying dural structures and venous sinuses.

Main Methods:

• Dissection of 43 fixed human cadaver heads.
• Creation of a burr hole at the asterion to examine the underlying cranial structures.
• Documentation of the proximity of the asterion to the transverse-sigmoid sinus complex and dural regions.

Main Results:

• The asterion was adjacent to the transverse-sigmoid sinus complex in 74.4% of right sides and 58.1% of left sides.
• The asterion was located over the infratentorial dura in 23.3% (right) and 32.6% (left) of specimens.
• The asterion was over the supratentorial dura in 2.3% (right) and 9.3% (left) of specimens.

Conclusions:

• The asterion is not a consistently reliable landmark for locating the posterior fossa dura.
• Its frequent association with the transverse-sigmoid sinus complex poses a risk during surgical procedures relying on this landmark.