Recurrent trigeminal neuralgia attributable to veins after microvascular decompression

OBJECTIVE: To demonstrate the cause of and optimal treatment for recurrent trigeminal neuralgia (TN) in cases where veins were observed to be the offe nding vessels during the initial microvascular decompression (MVD) procedur e. METHODS: An electronic search of patient records from 1988 to 1998 revealed that 393 patients were treated with MVD for TN caused by veins. The pain r ecurred in 122 patients (31.0%). Thirty-two (26.2%) of these patients under went reoperations. Clinical presentations, recurrence intervals, surgical f indings, and clinical outcomes were analyzed. RESULTS: Analysis of 32 consecutive cases of recurrent TN initially attribu table to veins revealed a female predominance (female/male 26:5), with one female patient exhibiting bilateral TN caused by venous compression. Patien t ages ranged from 15 to 80 years, with a prevalence in the seventh decade. The V-2 distribution of the face was involved more frequently than other d ivisions. For 24 patients (75%), recurrence occurred within 1 year after th e initial operation. At the time of the second MVD procedure, development o f new veins around the nerve root was observed in 28 cases (87.5%). After s uccessful subsequent MVD procedures, the pain was improved in 81.3% of the cases. CONCLUSION: The recurrence rate for TN attributable to veins is high. If pa in recurs, it is likely to recur within 1 year after the initial operation. The most common cause of recurrence is the development and regrowth of new veins. Even fine new veins may cause pain recurrence; these veins may be l ocated beneath the felt near the root entry zone or distally, near Meckel's cave. Because of the variable locations of vein recurrence, every effort m ust be made to identify recollateralized veins. Given the high rate of pain relief after a second operation, MVD remains the optimal treatment for the recurrence of TN attributable to vein regrowth.