Review of therapeutic failures of microvascular decompression in trigeminal neuralgia at a tertiary hospital.

Introduction: Microvascular decompression (MVD) is a non-ablative technique aimed at relieving pain in trigeminal neuralgia (TN) by resolving a neurovascular conflict. Despite reported high success rates, a significant percentage of patients experience therapeutic failure.

Methods: Retrospective observational study of patients with suspected TN undergoing MVD was performed with the goal of identifying factors contributing to the persistence and recurrence of pain.

Results: In the present study, 31 patients undergoing 38 MVD procedures for TN were included (7 patients underwent reoperation after the failure of the initial operation). The mean age was 58.5 years with a male predominance (58.1%). The mean duration of pain was 6.4 years, mainly affecting branches V2 and V3 (46.7%). The most frequently described neurovascular conflict was with the superior cerebellar artery (54.8%), predominantly resolved with Teflon (75.9%). In our case series, MVD achieved pain control in 80.6% of patients at one-year post-intervention and 61.3% at the end of the follow-up period. Twelve patients experienced MVD failure: 5 cases of persistent pain and 7 cases of pain recurrence. A detailed analysis of these failures identified misdiagnosis as the reason of persistent pain in 4 patients, while inadequate surgical technique could be the cause of pain recurrence in 6 patients.

Conclusion: In our study, therapeutic failures could mainly be attributed to two factors: misdiagnosis or the use of inappropriate materials. These factors should be considered when optimizing the management of DMV in patients with NT.