Suprameatal Tubercle Drilling During Microvascular Decompression for Trigeminal Neuralgia

Objective: The suprameatal tubercle (SMT) is a prominence of the petrous part of the temporal bone located above the internal acoustic meatus. An enlarged SMT can obstruct adequate visualization and decompression of the trigeminal nerve during microvascular decompression (MVD) surgery.

Methods: We retrospectively reviewed our single-surgeon experience in trigeminal neuralgia to identify preoperative correlates of required suprameatal drilling for MVD from January 1, 2009, to September 1, 2021.

Results: A total of 80 patients underwent MVD for trigeminal neuralgia during the study period. Nearly two-thirds of patients (54 patients) had type I neuralgia. Seventy four patients had significant relief of their pre-operative symptoms at last follow-up. No difference between type I and II were found in terms of long term outcome in this cohort. No patients sustained anesthesia dolorosa, corneal abrasion, or other cranial nerve deficit. Three patients developed CSF leak. SMT drilling was necessary for exposure of root entry zone and compression site in only three cases (4%). No complication related to this maneuver was encountered. Retrospective review of preoperative imaging identified the width of suprameatal tubercle (0.9 cm) correlated with the necessity for SMT drilling.

Conclusion: Suprameatal drilling may be required in TGN patients with wide, enlarged SMT for adequate visualization and microvascular decompression of the trigeminal nerve. Evaluation of pre-operative imaging with SMT width can predict the necessity of the additional drilling to achieve adequate decompression.

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Artikel online veröffentlicht:
15. Februar 2022