Mini-invasive Anterior Petrosal Intertentorial Approach for Trigeminal Neuralgia: Rationale and Limits of the Technique.

Background and Objectives: The retrosigmoid approach (RSA) is considered the standard surgical choice to address a neurovascular conflict involving the trigeminal nerve. The subtemporal transtentorial approach (STA) represents the main alternative. We describe here the mini-invasive anterior petrosal intertentorial approach with a view to reduce complications associated with the standard STA. Methods: Mini-invasive anterior petrosal intertentorial approach (M-APIA) was described for a case of refractory trigeminal neuralgia. This approach includes a very limited amount of drilling of the petrous ridge to expose the posterior fossa dura and the superior petrosal sinus to facilitate the subsequent tentorial peeling. Tentorial peeling enables to develop an intertentorial plane between the temporal tentorial leaf (TTL) and the posterior fossa tentorial leaf (PFTL). A linear incision over the posterior fossa dura and the PFTL offers a wide exposure of the neurovascular conflict. Results: M-APIA enables to expose the root entry zone (REZ) of the trigeminal nerve without exposing the temporal lobe or the cerebellum. Conclusion: M-APIA can be considered as a safe alternative to the RSA or STA for trigeminal microvascular decompression (MVD), especially for select cases. Additional studies are needed for a better understanding of its advantages and disadvantages.