The Jugular Process: A Key Anatomical Landmark for Approaches to the Jugular Foramen.

OBJECTIVE

To describe the morphology and anatomical relationship of the jugular process (JP) and to elucidate its utility as a surgical landmark in the lateraland posterior lateral approaches to the jugular foramen.

MATERIALS AND

METHODS

Eight dry adult skulls and 10 silicon-injected cadaver heads were used for this study. The distances to selected structures and the thickness of the JP at 3 selected sites were measured. We also included the data of 20 thin-sliced 3-dimensional computed tomography scans. The radiology data of these patients were transferred to a workstation for 3-dimensional reconstruction.

RESULTS

The JP, an irregular trapezoid structure, is an important surgical landmark when approaching the jugular foramen. Laterally the JP is rough with 1 or 2 prominences to which the rectus capitis lateralis is attached. The JP is relatively flat medially. The condylar part of the occipital bone could be conceived as a "3-story building." The JP, hypoglossal canal, and lateral and posterior condylar emissary veins are located on the middle floor. The stylomastoid foramen is found constantly in the triangle formed by the styloid process, JP, and the base of the mastoid process.

CONCLUSIONS

The JP is an important surgical landmark in the identification of jugular foramen, especially in the lateral and posterior approaches. A better understanding of its morphology and its relationship with the surrounding structures is a prerequisite for accurate surgical planning and intraoperative orientation.