Suprameatal Extension of Retrosigmoid Approach in Microvascular Decompression for Trigeminal Neuralgia with Petrous Endostosis: Case Report and Literature Review.

Petrous endostosis or prominent suprameatal tubercle is a rare entity which may prevent adequate microscopic exposure of the trigeminal nerve root entry zone during microvascular decompression (MVD) for trigeminal neuralgia. We present a rare case of trigeminal neuralgia (TN) with petrous endostosis, which was managed adequately by partial removal of the prominent suprameatal tubercle to improve the obscured site of neurovascular conflict and enabled complete MVD. Through this manuscript, we additionally discuss the nuances involved in this extension of the standard retrosigmoid approach in light of the published literature. Petrous endostosis encountered during MVD for TN can impose an operative challenge. Suprameatal extension of the standard retrosigmoid approach improves exposure at the site of neurovascular conflict but requires utmost care and attention to avoid complications. We emphasize recognizing this anatomical variation in the preoperative period to predict an operative difficulty, ensure appropriate patient counselling, and avoiding surgical complications.