Cross-clamping of the three hepatic veins in the piggyback technique is a safe and well tolerated procedure.

A common stump of the three hepatic veins has always been used to fashion the upper vena cava anastomosis in 205 liver transplantations with the piggyback (PGB) technique performed in our Unit, to avoid outflow problems. The aim was to study the repercussion of lateral inferior vena cava (IVC) clamping on IVC flow and pressure as well as on systemic hemodynamics. We have studied 42 orthotopic liver transplantations performed with the PGB technique. Intraoperative IVC blood flow measurements by transit time ultrasonic volume flowmetry, IVC pressure, and systemic hemodynamics were taken before and after lateral IVC clamping. Graft outflow complications, stenosis or kinking of the upper vena cava anastomosis have not been found in any of the 205 PGB procedures. A significant decrease of IVC flow (23%) and cardiac output (12%) occurred after IVC clamping, whereas mean arterial and central venous pressures were not altered significantly, probably due to an increase (25%) of systemic vascular resistance. Only in one case was an almost total clamping of IVC needed. Venovenous bypass was not needed in any case. Renal perfusion pressure was adequate in all cases. We conclude that the use of a common stump of the three hepatic veins for upper vena cava anastomosis in the PGB technique is safe because any outflow problem of the graft is avoided and, at the same time, is well tolerated hemodynamically because most of the IVC flow is preserved.