Elsevier

World Neurosurgery

Volume 128, August 2019, Pages e859-e864
World Neurosurgery

Original Article
Rectus Capitis Lateralis Muscle: A Cadaveric Study of a Key Surgical Landmark in the Posterior and Lateral Approaches to the Jugular Foramen

https://doi.org/10.1016/j.wneu.2019.05.018Get rights and content

Objective

The rectus capitis lateralis (RCL) is a small cervical muscle that arises from the transverse process of C1 and is intimately related to the jugular process and jugular foramen. We describe its morphology, neurovascular relationships, and its utility as one of the key surgical landmarks in approaches to the jugular foramen.

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.

Introduction

The jugular process forms the posterior margin of the jugular foramen (JF) and is attached to the posterior half of the occipital condyle. The rectus capitis lateralis (RCL) is attached to the jugular process and it is 6.2 mm posterior to the internal carotid artery.1 The medial, lateral, and posterior surgical corridors are the most used surgical corridors in accessing tumors surrounding the JF. Infrequently the JF is approached endoscopically.2 The key in these approaches is the identification of a reliable surgical landmark to avoid injuries to critical adjacent neurovascular structures.3, 4 In this study, we describe the morphology of the RCL, its neurovascular relationships, and its utility as a surgical landmark in the posterior and lateral approaches to the JF.

Section snippets

Specimen Preparation and Anatomical Study

Eight cadaveric heads (16 sides) semifixed with formaldehyde were used for this study. The arteries and veins were washed and injected with red (arteries) and blue (veins) silicone (Dow Corning, Midland, Michigan, USA). The dissections were performed under 3–40× magnification Zeiss microscope (Carl Zeiss Co., Oberkochen, Germany). Posterior and lateral approaches were performed on all the cadaveric heads on both sides. Bone dissection was carefully performed with a high-speed drill (Medtronic,

The Morphology of RCL

The cranial end of the RCL approximates the roughly square shape of the bony prominence of jugular process (Figure 1). Conversely, the inferior end of the muscle is flat as it attaches to the transverse process of C1. In the 8 heads studied, the average craniocaudal length of the RCL was 21.3 mm (range 20–23 mm). The distance from the posterior margin to the anterior aspect of the RCL was 6.5 mm (range 6–7 mm) at the cephalad end where it inserts to the jugular process.

The Relationship

The RCL is located

Discussion

The list of the various approaches to the JF is as complex as its anatomy.2, 3, 4, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 The goal of the approaches is to control the VA, CNs VII-XII, and jugular−sigmoid complex. The workhorse of most of the JF tumors is the far lateral approach with its variants and or combination with the transmastoid approaches.20 The endoscopic endonasal approach is rarely used for primary JF tumors except for those that extend from the petroclival region to the

Conclusions

The RCL represents an important anatomic landmark for early identification of VA, IJV, facial nerve, and CNs IX–XII. It is the boundary between posterior and lateral approach to JF, typically the far lateral approaches and transmastoid approaches.

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  • Cited by (2)

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

      2020, World Neurosurgery
      Citation Excerpt :

      The protuberances are most likely produced by the muscular traction from the RCL. Any surgical manipulation beyond the lateral margin of the RCL and lateral occipital ligament may injure the facial nerve.17-19 The JP, lateral occipital ligament, and the RCL should be considered the transition or watershed area for safe preservation of the facial nerve in posterior approaches to the JF.

    Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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