Importance of prevention of intravenous thrombosis and preservation of the venous collateral flow in bridging vein injury during surgery: an experimental study.

BACKGROUND: Venous infarction (cerebral edema and/or hemorrhage) may occur several hours after sacrifice of the bridging vein during surgery. However, in our experience, severe venous infarction is often produced by prolonged brain retraction in addition to sacrifice of the vein.
METHODS: The experiment was carried out using 20 adult cats. In five cats, all bridging veins were coagulated near the superior sagittal sinus and 12 hours later the surgical wound was closed (group A). In five other cats, a round plate weighing 45 g was placed on the center of the Sylvian fissure for 12 hours and then the wound was closed (group B). In the remaining 10 cats, both of these interventions were performed (group C). All 20 animals were sacrificed 12 hours after the wound closure.
RESULTS: The degree of Evans-blue dye leakage and brain edema was much more marked in the group C than in groups A and B. The endothelial intactness of the bridging veins studied by staining with a factor VIII-related antigen was much more disturbed in group C than in the other groups.
CONCLUSIONS: The endothelium of the cortical veins is damaged much more by the combination of sacrifice of the vein and brain retraction, and this endothelial damage of the cortical vein leads to extensive venous infarction.