LAUSR

BACKGROUND It is crucial to identify a shunt point for a spinal arteriovenous malformation (AVM) treatment. For this purpose, some intraoperative supports have been reported-the intravenous injection of indocyanine green (ICG), selective arterial injection of ICG (SAI-ICG), and selective arterial injection of saline with a high frame rate digital camera. However, there are difficulties in accurately identifying the shunt point, especially if the lesion has multiple feeders. We here report a novel method, the selective arterial injection of saline to subtract signals of ICG (3S-ICG), to precisely identify the perimedullary arteriovenous fistula shunt points having multiple feeding arteries METHODS: After exposing the lesion, a 4-Fr catheter was cannulated into the origins of the segmental artery. ICG was injected intravenously as a first step, and then, heparinized saline solution was flushed from the catheter. RESULTS Compared with other methods, this method could point out the exact shunt point and was effective for certain shunt point obliterations. CONCLUSION Though having similar invasiveness, 3S-ICG is superior to previously described techniques, such as SAI-ICG. Therefore, it will be useful when spinal AVM surgical treatment is performed.