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 χ(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 (χ(2) = 16.307, P < 0.01)/the relief rate of neurovascular compression (NVC) (χ(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 (χ(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.