The extreme lateral approach to the craniovertebral junction: An anatomical study

Background: The extreme lateral approach is a direct lateral approach which allows a good control of the entire length of the vertebral artery (VA), the jugular foramen, the lowest cranial nerves, and the jugular–sigmoid complex. Herein we try to exploit the variants of the approach and we identify indications, advantages, and disadvantages. Methods: All phases of the study were conducted at the Institute of Public Health Section of Legal Medicine and Insurance of the University. We performed the extreme lateral approach in four subjects, who died between 24 and 48 h before in non-traumatic circumstances (three men and one woman). Results: The great auricular nerve, the spinal accessory, the branches of the first ventral spinal nerves, the jugular vein, and the vertebral artery were identified in all the cadavers. In all cases the right VA exited from the transverse foramen of C1. The site of SCM piercing the accessory nerve was at a distance from the tip of the mastoid between 3 and 4 cm (3.3 in one case, 3.4 in 2 cases, and 3.7 in one case). No vessels and nerves have been damaged after being identified and isolated. Conclusions: Extradural lesions at the ventro-lateral aspect of the CVJ may require an extreme lateral approach, a procedure more aggressive comparing with far lateral approach, which represents a reasonable option for large anterior and anterolateral lesions when greater exposure is required.