Importance of portal flow diversion in experimental auxiliary partial orthotopic liver transplantation

Background. Auxiliary partial orthotopic liver transplantation (APOLT) has successfully been performed in patients with noncirrhotic metabolic disease s. It remains, however, unclear if intervention in the portal venous inflow is necessary to ensure adequate portal blood flow to graft and host liver. In this experimental study we evaluate the hepatic flow during APOLT. Methods. Left lateral/medial segmental grafts were transplanted from beagle to dalmatian dogs. Vascular structures mere anastomosed end-to-end. The ef fect of diversion of the portal flow was studied in three groups: in the li gation group (n=3) the host portal vein was tied off, the free flow group ( n=6) had random flow to both livers. In the banding group (n=11) the host p ortal vein was banded with a adjustable strap-band to restore the pretransp lantation flow distribution. Results, After reperfusion the blood flow through the common portal vein de creased from 49 to 36 ml/kg/min (P<0.03) in all animals. Flow through the l eft portal vein decreased from 26 to 5 ml/kg/min (P<0.0001). Banding restor ed the flow in the left portal vein to 12 ml/kg/min, although the flow in t he free-flow group remained 4 ml/kg/min. In the ligation group the total po rtal flow was forced toward the graft leading to the highest perfusion: 24 ml/kg/min (P<0.005). Adverse effect of this ligation was the development of portal hypertension. Conclusions, This experimental study confirms that diversion of the portal flow is necessary for adequate graft perfusion in APOLT. Banding can restor e the pretransplantation flow distribution, without compromising the flow i n the common portal vein.