METHODS: Eight cadaveric heads were used to perform far-lateral and transmastoid approaches to the jugular foramen. The neurovascular relationships of the RCL were studied.
RESULTS: The RCL originates from the transverse process of C1 and inserts onto the jugular process. It can be found in the muscular interval between the posterior belly of the digastric muscle and the superior oblique muscle with the occipital artery coursing between it and the posterior belly of the digastric muscle. It lies directly posterior to the internal jugular vein and cranial nerves (CNs) IX-XI as they exit the jugular foramen. The vertebral artery courses medially to the RCL as it exits foramen transversarium of C1. As the facial nerve exits the stylomastoid foramen, it is anterolateral to the RCL before turning to enter the parotid gland. The CN XII is seen between the RCL and the occipital condyle from a posterior view.
CONCLUSIONS: The RCL usually is preserved unless jugular process needs to be removed to expose the jugular foramen. The RCL is an important surgical landmark for the early identification of the vertebral artery, internal jugular vein, facial nerve, and CNs IX-XII in approaches to the jugular foramen.