Cerebellar Infarction Following Division of Dandy's Vein in Microvascular Decompression for Trigeminal Neuralgia

Objectives: Does dividing Dandy's (superior petrosal) or other tentorial veins increase the risk of cerebellar infarction following microvascular decompression (MVD) of the trigeminal nerve?

Design: A retrospective review of all patients with trigeminal neuralgia who underwent MVD by the senior author between 1999 and 2012.

Materials and Methods: Patients were identified from operative logbooks and discharge summaries. Data were collected from the medical notes.

Results: Of 162 patients who underwent microvascular decompression of the trigeminal nerve, we had a 96% follow-up rate, which provided 156 of the operative cases for review. Over 75% report to be neuralgia free at first follow-up. Cerebellar infarction occurred in six patients, all of whom had division of the superior petrosal or tentorial veins. Fifty-one patients did not suffer cerebellar infarction following division of Dandy's or other tentorial veins. In our series, this gives an overall risk of 3.85% of cerebellar infarction following microvascular decompression of the trigeminal nerve. In the group of patients that had division of the veins, 9.5% experienced cerebellar infarction.

Conclusions: Since Walter Dandy's original description of microvascular decompression of the trigeminal nerve through a retrosigmoid approach, it has been suggested that it is safe to divide the superior petrosal or any other bridging vein. In this series of 156 cases, 6 patients experienced a cerebellar infarction associated with the division of part of Dandy's vein alone or in association with division of tentorial veins. We would suggest that with a rate of 9.5% of cerebellar venous infarction, division of any bridging veins should only be considered if absolutely necessary.