The jugular foramen: a comparative radioanatomic study.

BACKGROUND

Advances in microsurgical techniques made possible the removal of advanced jugular foramen (JF) lesions, which once had been accepted as unoperable. However, successful surgery requires detailed knowledge of the JF anatomy.

METHODS

Sixteen jugular foramina in eight formalin-preserved adult cadavers were scanned with axial and coronal high resolution computed tomography (HRCT) prior to dissection. After craniectomy and removal of brain tissue, the relationships of the neurovascular structures in the JF were determined by drilling the temporal bones from superior to inferior on planes parallel to the skull base.

RESULTS

No bony partition of the JF was observed. A dural band consistently divided the JF into two parts. Anterior to it was the glossopharyngeal nerve (IX) while the vagus (X) and accessory (XI) nerves were located posteriorly. There was a notch in which the IX nerve entered the JF. It was also identified on the CT scans and defined as the glossopharyngeal recess. The IX nerve made a genu within the JF in all specimens. Then, it ran inferiorly through a bony canal in three specimens (18.75%), and through an incomplete bony canal in two (12.5%), which were also defined on the CT images. The inferior petrosal sinus ran through a sulcus anteromedial to the glossopharyngeal recess. The posterior meningeal artery was found to be located between the X and XI nerves within the JF.

CONCLUSIONS

This study revealed a complex and highly variable pattern of the relationships of the neurovascular structures in the JF, and their HRCT images correlated well with the anatomic microdissections.