Microsurgical posterior fossa exploration for trigeminal neuralgia: a study on 48 cases

The authors present their experience in the microsurgical treatment of trigeminal neuralgia (TGN). Over the last five years 48 patients were explored and 34 (71 %) underwent microvascular decompression (MVD) for significant arterial or venous conflicts. The remaining 14 patients (29 %) underwent partial sensory rhizotomy (PSR) because of negative intraoperative findings (simple contact or no conflict). Excellent or good immediate outcomes were achieved in 87.5 and 12.5 % of patients, respectively. Of the three severe recurrences observed during the follow-up period (24.7 months; range: 7 - 65 months), two underwent percutaneous microcompression and one posterior fossa reexploration, which revealed teflon-induced recompression. None of the PSR cases experienced incapacitating face numbness. MVD, an extremely effective procedure in the immediate post-operative period, is burdened in the long term by 20 % recurrences, the majority occurring within two years from surgery. We believe that careful intraoperative evaluation of the conflict entity could be the key to achieve a significant reduction of recurrences: overestimation of simple vascular contact of doubtful etiologic relevance, may lead to ineffective decompression and unsatisfactory results. In our opinion PSR should be preferred to percutaneous treatments in cases of negative exploration (contact or no conflict). In accordance with others we observed that section of half or less of the inferolateral "portio major" allows long-lasting pain relief and good preservation of sensory function.