360-Degree Approaches to the Craniocervical Junction: A Technical and Anatomical Overview of the Far Lateral, Anterolateral, and Endoscopic Endonasal Far Medial Approach

Introduction: Surgical treatments of ventral and ventrolateral lesions of the craniocervical junction are among the most challenging neurosurgical pathologies to treat. Three surgical techniques, the far lateral approach (and its variations), the anterolateral approach and the endoscopic far medial approach can be used to approach and resect lesions in this area.

Objective: To examine the surgical anatomy of three skull base approaches to the craniocervical junction and review surgical cases to better understand the indications and possible complications for each of these approaches.

Methods: Cadaveric dissections with standard microsurgical and endoscopic instruments were performed for each of the three surgical approaches, and key steps and surgically relevant anatomy were documented. Six patients with appropriate pre-, post-, and intraoperative imaging and video documentation are presented. In addition, morphometric measurements of approach related anatomic structures were obtained on 20 cranial CT scans of patients without intracranial pathology.

Results: Based on our institutional experience, all three approaches can be utilized to safely and effectively approach a wide variety of neoplastic and vascular pathology. Unique anatomic characteristics, lesion morphology and size, and tumor biology should all be considered when determining the optimal approach. CT-derived morphometric characteristics of the far lateral, anterolateral and far medial approach, respectively, are as follows:

Depth of Surgical Field: 5.9 cm (0.5, 4.8–6.8), 5 cm (0.6, 4.4–6.7), 10.2 cm (0.5, 9.3–11)

Surgical Freedom: 56° (3.4, 50.4–62.7) × 58.7° (6.2, 50–74.6), 36.2° (2.9, 30.6–41.6) × 35.5° (2.9, 30.6–41.6), 13.7° (1.2, 12.1–16.3) × 27.1° (2.9, 22–23.4)

Exposure of Brainstem/Spinal Cord: 66.3° (12.2, 60–90), 168° (14.7, 150–180), 106.5° (17.7, 90–150)

Conclusion: Preoperative assessment of surgical corridors with 3D illustrations helps to define the best surgical corridor. 360-degree knowledge of the anatomy of craniovertebral junction allows safe surgical approach and treatment of ventral and ventrolateral located lesions using one of the three approaches.

Publication History

Article published online:
15 February 2022