Evolution of Microvascular Decompression for Trigeminal Neuralgia: Surgical Technique and Initial Outcomes of Transposition and Transposition Sling

Introduction: Trigeminal neuralgia (TN) is a facial pain disorder caused typically by arterial compression of the trigeminal nerve. The current gold standard for TN is microvascular decompression (MVD) with an interposition technique whereby Teflon is placed between the nerve and vessel. Refractory TN pain, however, can be attributed to Teflon migration, adhesion formation, and compression from the Teflon itself. New transposition methods for decompression have been described in limited case series. In this study we report our institution’s experience transitioning away from interposition MVD towards transposition with teflon and tentorial slings.

Methods: A retrospective chart review was performed on TN patients who underwent surgical intervention from July 2016 to 2022. Demographic, surgical, and clinical variables were assessed, including compressive vessel, compression site and severity, Barrow Neurological Institute (BNI) pain intensity scores, and complications.

Results: 196 patients underwent surgical intervention for TN, including 21 patients who underwent interposition MVD, 70 patients who received teflon transposition, and 25 patients with transposition with tentorial slings. BNI I (pain-free, off-meds) outcomes at last follow-up were 61.9%, 70%, and 80% for interposition MVD, teflon transposition, and tentorial sling patients, respectively. Among treatment groups, there were no differences in gender, age, symptom duration, number of prior procedures, MRI evidence of vascular compression, and involved TN dermatome. As expected, tentorial sling patients had shorter follow-up durations. The interposition cohort had significantly more compression from AICA. Post-op paresthesias, dysesthesias, and complication rates were similar. A propensity score matched comparison between interposition MVD and transpositional sling patients showed a trend towards higher BNI I outcomes in the latter group (61.5% vs 80%, p = 0.09).

Conclusion : This is one of the largest series comparing transposition techniques to traditional interposition MVD for TN. Our short-term findings highlight the efficacy of transposition techniques without increased complication rates. Further studies will assess for longer-term pain-free durability.