Assessment of collateral venous flow using temporary clip placement at ICG videoangiography

Background As there are many collateral pathways between venous systems, intraoperative venous injury rarely induces venous infarction. In some patients, however, venous injury during microsurgical manipulation may cause acute and/or delayed serious complications. Although intraoperative evaluation using indocyanine green (ICG) videoangiography is very useful, it is difficult to assess the flow direction using this technique. Method A simple technique using temporary clips and ICG videoangiography was applied to assess the collateral venous pathway in 4 cases of surgical manipulation-related injury or occlusion of the main superficial Sylvian vein in patients with aneurysm. Results The flow direction and collateral pathway can be easily visualized after release of temporary occlusion. Conclusions A collateral venous pathway can be evaluated with the present simple technique described here.