Surgical text for orthotopic liver transplantation model with small-for-size graft in the pig: key techniques and pitfalls.

BACKGROUND: Challenges with small-for-size grafts are a critical issue in the liver transplantation field, and a reliable and reproducible animal model is required. METHOD: We performed 50 orthotopic liver transplantations in pigs with a 30% graft, and retrospectively investigated the learning curves. We modified our surgical procedures according to our experience. Here, we describe our current procedures in detail with retrospective evaluation of our experience. The artery to the right lateral lobe crosses the portal vein trunk. A 30% graft is taken using the right lateral lobe attached to a sufficient length of aorta. Hepatic venous plasty is undertaken on the back table to attach a venous patch to the anterior wall of the suprahepatic inferior vena cava, which has no extrahepatic margin. To minimize hypoperfusion to the digestive tract, an aorta-to-aorta anastomosis is performed in a side-to-end fashion in a minimal surgical field before suprahepatic inferior vena cava and portal vein reconstruction. A temporary transjugular portosystemic shunt is also inserted before suprahepatic inferior vena cava reconstruction. The recipient suprahepatic inferior vena cava is clamped at the intramediastinal level, including the margins of the diaphragm in the clamp. RESULTS: Although survival rate during first forty cases were under 0.2, a reasonable survival rate of 0.6 had been achieved after the experiences of forty cases. CONCLUSION: Precedent arterial reconstruction using an aorta-to-aorta anastomosis minimizes congestive damage and shortens operative time. Hepatic venous reconstruction should be completed without any outflow block, by using venous plasty and adequate clamping.