Microsurgical Anatomy of the Fasciae Attaching to the Skull Base

Background A profound understanding of the microsurgical anatomy between cervical fasciae and skull base is essential for the skull base surgery. Though many groups have studied the fascia of the neck and cranial lesion, to our knowledge, there has been little study on the relationship between the many cervical fasciae and skull base. This study aims to examine the fascial layers attaching to the skull base based on cadaveric dissection.

Methods This is a cadaveric study. Two cadaveric heads are dissected from the inferior and medial aspects and expose the fascial layers attaching to the skull base step by step.

Results Cadaveric dissection exposed the widely recognized fasciae, which include the interpterygoid, tensor-vascular-styloid, buccopharyngeal, alar, and prevertebral fasciae. The interpterygoid and tensor-vascular-styloid fasciae are attached to the skull base along the sphenopetrosal fissure. Buccopharyngeal fascia attached to the pharyngeal tubercle on the inferior surface of the basilar part of the occipital bone and petro-occipital synchondrosis. On the middle of the clivus, thick fibrocartilaginous tissue was found and the prevertebral and alar fasciae were fused to this area. Buccopharyngeal, tensor-vascular-styloid, and alar fasciae form the fascial network for the carotid sheath around the internal jugular vein and the carotid artery. The fascia that covers the rectus capitis lateralis and attaches to the occipitomastoid suture also blends into the fascial network of the carotid sheath. The carotid sheath attaches anterolaterally to the vaginal process and posteromedially to the fibrocartilaginous tissue around the jugular foramen and carotid canal.

Conclusion This study displayed the facial layers related to the skull base. Our cadaveric dissection supports previous findings on imaging-anatomical studies. A precise knowledge of these fascial layers is essential for accurate diagnosis and understanding the spread of disease, and helps skull base surgeons perform challenging approaches safely.