The transsylvian approach is a versatile treatment method for aneurysms of the anterior circulatory system. Studies have shown that sylvian veins run in various patterns, suggesting the need for dissection between veins to obtain appropriate surgical corridor. In case of inadvertent sylvian vein injury, serious complications such as venous congestion may occur. We herein describe the "side-to-side anastomosis reconstruction technique" of the resected superficial sylvian vein. This technique can be effective for the reconstruction of other cortical veins, and indocyanine green videoangiography was effective in determining the indications for venous reconstruction.