Findings and long-term results of subsequent operations after failed microvascular decompression for trigeminal neuralgia.

OBJECTIVE: To evaluate the indication of subsequent operations after failed microvascular decompression (MVD) for the treatment of trigeminal neuralgia, the intraoperative findings and long-term results of 16 subsequent operations are reported. METHODS: Subsequent exploration of the posterior fossa was performed for lack of pain relief (3 patients) and recurrent neuralgia (13 patients) after an average of 17 months (range, 4-62 mo). In all patients, typical arterial compression patterns at the root entry zone of the trigeminal nerve were found in the first procedure. The mean follow-up period after subsequent operation was 90 months (range, 78-104 mo). RESULTS: New arterial neurovascular conflicts were found in nine patients. After subsequent MVD procedures, seven patients were pain-free (with one recurrence after 6 mo), one had constant marked relief, and one was unchanged. Second exploration revealed no abnormalities in the other seven patients who experienced continued or recurrent pain; only careful neurolysis of the trigeminal nerve was performed in those patients. Initially, all seven patients obtained complete pain relief, but two experienced late recurrences after 64 and 68 months, respectively. Thus, subsequent operations failed in all 4 patients who had undergone prior destructive procedures but were successful in those 12 patients who had undergone only previous MVD. Two patients developed severe sequelae, and the other nine had minor complications, especially permanent (four patients) or transitory (three patients) ipsilateral trigeminal hypoesthesia. CONCLUSION: Subsequent MVD seems to have good long-term results. However, because of the significantly high incidence of complications, the indication for subsequent operations should be restricted to younger patients to avoid destructive procedures. In general, glycerol rhizolysis or radiofrequency rhizotomy may be the treatment of choice after failed MVD.