Indocyanine Green (ICG) Temporary Clipping Test to Assess Collateral Circulation Before Venous Sacrifice

BACKGROUND: As a general principle, sacrifice of cerebral veins at surgery is avoided. However, at times sacrifice of a vein may be desirable to increase surgical exposure. At present, no method exists to predict whether such sacrifice will be accommodated by the presence of collateral venous drainage. We show a simple technique to examine cerebral venous blood flow using indocyanine green videoangiography. METHODS: In two patients, parasagittal meningiomas were found to be associated with paramedian veins that impeded complete removal of the tumors. The suitability of veins removal was assessed by applying a temporary aneurysm clip and performing an indocyanine green videoangiogram. RESULTS: In one patient, stasis was observed in the vein. In the second patient, a collateral flow allowed the venous blood to drain. The former test was considered a counterindication for venous sacrifice, whereas the latter supported its feasibility. The vein was preserved in the former case and coagulated in the latter. In both cases, the patients did well. CONCLUSIONS: Although our limited study cannot prove that venous congestion or infarction can be avoided with this technique, it does provide direct evidence of the presence or absence of collaterals that can help guide intraoperative surgical decision-making.