Indocyanine green videoangiography for vessel identification and preservation prior to dural opening for microvascular decompression.

Unexpected bleeding from the dural sinus can sometimes occur when performing a dural opening during microvascular decompression. We conducted dural opening safely by performing indocyanine green (ICG) videoangiography before making a dural incision. We introduce two specific cases in which surgery was performed to treat a trigeminal neuralgia. In both cases, a small craniectomy was performed in the transverse-sigmoid junction. ICG (0.25 mg/kg dose) was administered intravenously just prior to dural opening. Using a microscope equipped with fluorescent filters, real-time flow assessment of the underlying veins was done. ICG videoangiography allowed for a clear confirmation of the margins of the dural sinus as well as the vascular structures at the surface of the cerebellum, which were clearly seen through the dura mater. Performing ICG videoangiography prior to dural opening makes it possible to safely perform dural opening.