Extreme lateral supra cerebellar infratentorial approach: Surgical anatomy and review of the literature.

OBJECTIVE: The extreme lateral supracerebellar infratentorial (ELSI) approach has the potential to access several distinct anatomical regions, otherwise difficult to reach. The surgical anatomy is illustrated through cadaveric dissections. An extensive review of the literature is provided in order to highlight the versatility of this approach along with its limits and comparisons with alternative approaches.

METHODS: The surgical anatomy of the ELSI was described through one adult injected cadaveric head. Formalized non-injected brain specimens were also dissected to describe the brain parenchymal anatomy of the region. An extensive review of the literature was provided, according to each targeted anatomical region. Illustrative cases are also presented.

RESULTS: The ELSI approach allows a wide exposure of the middle and postero-lateral incisural spaces allowing direct access to centrally located intra axial structures like the splenium, pulvinar, brainstem and mesial temporal lobe. In addition, for skull base extra-axial tumors like petroclival meningiomas, the ELSI represents a rapid and adequate method of access without the use of extensive skull base approaches.

CONCLUSION: ELSI approach represents one of the most versatile approaches with respect to its ability to address several anatomical regions centered on the posterior and middle incisural spaces. For intra-axial pathologies, the approach allows access to central core of the brain with several advantages when compared to alternate approaches that frequently involve significant brain retraction and cortical incisions. In specific cases of skull base lesions, the ELSI is an elegant alternative to traditionally used skull base approaches, thereby avoiding approach related morbidity.