Safe and accurate sylvian dissection with the use of indocyanine green videoangiography

BACKGROUND: Sylvian dissection is an essential microneurosurgical skill for neurosurgeons. The safe and accurate opening of the sylvian fissure is desirable for a good prognosis. METHODS: The aim of this report is to demonstrate the use of indocyanine green (ICG) videoangiography to recognize the superficial sylvian vein (SSV) and thus enable a wide opening of the sylvian fissure, especially in patients with subarachnoid hemorrhage (SAH). RESULTS: The small tributary flowing into the SSV was distinguishable from a passing one, which deeply entered the insula. In addition, an entering point of a tributary to the SSV, which ran perpendicular to the insula, was occasionally determined. SSV, which was barely discernable in a reddish SAH involving the sylvian fissure, was clearly demarcated using ICG videoangiography. Two representative cases of sylvian dissection are herein presented. CONCLUSION: The performance of ICG videoangiography before sylvian dissection is a simple and useful method for identifying a vital approach route for safe and accurate sylvian dissection, and it reduces the risk of causing any accidental injury to the veins in the sylvian fissure.