Predicting the Outcome of Microvascular Decompression for Primary Trigeminal Neuralgia by the Use of Magnetic Resonance Tomographic Angiography

Background: Microvascular decompression (MVD) has been the available method to cure trigeminal neuralgia (TN), and several factors have been discussed as significant predictors of excellent outcome after MVD. Objective: This study aimed to find out the value of magnetic resonance tomographic angiography (MRTA) in predicting the outcome of MVD for TNs. Method: A total of 157 cases of TNs who underwent MVD have taken MRTA preoperatively and postoperatively and then were followed up for 5 years. The possible prognostic factors were analyzed by chi(2) test and Kaplan-Meier survival analysis. Result: Five years after MVD, 83.4% (131 cases) gave excellent, 10.2% (16 cases) gave good, and 6.4% (10 cases) gave poor results. A significant difference was found between the severity of postoperative neurovascular compression (chi(2) = 16.307, P < 0.01)/the relief rate of neurovascular compression (NVC) (chi(2) = 17.221, P < 0.01) and the outcome after MVD. However, no significant correlation was found between the severity of preoperative NVC and the outcome (chi(2) = 6.275, P = 0.329). The Kaplan-Meier survival curves showed that lower degree of postoperative NVC severity group and higher relief rate group had better pain relief after MVD. Conclusions: Postoperative MRTA can help us predict the outcome of MVD; less severity of postoperative NVC and more relief of compression could be possible prognostic factors.