Long-term outcome of microvascular decompression for typical trigeminal neuralgia with autologous muscle: an analysis of 1025 patients from a developing country

OBJECTIVE The objective was to evaluate the long-term outcome of microvascular decompression (MVD) utilizing autologous muscle for trigeminal neuralgia (TGN). METHODS A retrospective review was performed of all first-time MVD patients for typical classic TGN without prior surgical intervention who were treated between 2000 and 2019 at a tertiary supraregional neurosurgery practice. Demographic characteristics, surgical findings, operative results, complications, and recurrence rates at 1 year, 5 years, and last follow-up were collected. Pain outcome was assessed using the Barrow Neurological Institute (BNI) pain score. The chi-square test with continuity correction was used to compare categorical variables, and Kaplan-Meier curves and Cox regression were used to identify factors associated with recurrence. RESULTS In total, 1025 patients were studied with a median (interquartile range [IQR]) (range) follow-up of 8 (5-13) (3-20) years. In the immediate postoperative period, 889 patients (86.7%) had complete pain relief and 106 (10.3%) had partial pain relief; neither group required medication, and 30 patients (2.9%) had no relief. One hundred forty-one recurrences (13.8%) occurred over a median (IQR) of 3 (2-6) years after surgery. The proportion of patients without recurrence was 97% at 1 year, 90% at 5 years, 85% at 10 years, 82% at 15 years, and 81% at 20 years. There was no significant difference in the probability of recurrence between patients with complete (114/907 [12.6%] recurrences) or partial (19/106 [17.9%] recurrences) postoperative pain relief (p = 0.124, log-rank test). Patients with venous compression (n = 322) had a significantly higher rate of MVD failure (n = 16 [5%]) compared to those with arterial compression (14/703 [2%]) (p = 0.015, chi-square test). In the Cox proportional hazards model, venous compression and lack of immediate postoperative pain relief had hazard ratios of 1.62 (95% CI 1.16-2.27) and 2.65 (95% CI 1.45-4.82) for recurrence, respectively. One hundred twenty-four (12.1%) complications were documented, including facial numbness (44 [4.3%]), facial nerve palsy (37 [3.6%]), CSF leak (13 [1.3%]), and diplopia (5 [0.5%]), which resolved in all patients. CONCLUSIONS MVD with autologous muscle provides long-lasting pain relief in TGN patients with vascular compression with minimum morbidity and is a viable alternative to synthetic materials.