Comparison of hemodynamic changes in two veno-venous bypass techniques modified at the portal cannulation site.

Veno-venous bypass under total vascular exclusion is a useful technique to permit safer resection of hepatic malignancy. We describe here a retrospective study of two modified venous bypass techniques as alternatives to the conventional end-on portal cannulation technique. Portal decompression via inferior mesenteric vein access was performed in eight patients (group A), and portal decompression via a passive shunt between a branch of the mesenteric vein and the right saphenous vein was performed in a second group (group B; n = 8). Both techniques were used in hepatic resection for malignancy under total vascular exclusion. To assess the efficacy of these bypass techniques, we compared the hemodynamic changes in the two groups. There were no differences in the bypass flow between the two groups. Neither group showed any significant changes in hemodynamic parameters (including mean arterial pressure, cardiac index, systemic vascular resistance index, and pulmonary artery pressure) between the pre-bypass and bypass phases. The heart rate in the bypass phase was significantly increased compared to that in the pre-bypass phase in both groups. All hemodynamic parameters in each phase were similar in the two groups. We conclude that both techniques maintained adequate venous return and stabilized the hemodynamic changes during hepatic resection under total vascular exclusion, and that either technique can be selected according to the intraoperative situation.