[Canine partial liver transplantation using gradual occlusion of the portal vein].

Orthotopic liver transplantation in children is often limited by the scarcity of a compatibly size-matched donor organ. The transplantation of a reduced liver was conceived to circumvent this problem. We report herein a new technique of orthotopic partial liver transplantation in mongrel dogs, which partially retains the host's right lobe and uses an Ameroid constrictor which allows for a gradual occlusion of the host's right portal branch. After right (lateral right lobe, caudate process of caudate lobe) and median (medial right lobe, quadrate lobe) lobectomy, the donor's left lobe (lateral and medial left lobes) was perfused in situ and removed as a graft. It was then transplanted orthotopically in the space after left and median lobectomy of the recipient. An Ameroid constrictor was applied around the host's right portal branch for the gradual occlusion of the hepatic blood supply. Cyclosporin-A and methylprednisolone were given as immunosuppressants, postoperatively. Eighteen of 25 dogs survived more than 24 hours, and 6 dogs lived more than 10 days, -i.e., 19, 16, 15, 13, 13 and 13 days, respectively. At autopsy, the microscopic appearance of the graft showed little evidence of rejection. This method has some clinical advantages, one is the availability of the reduced graft, another is that it makes an extracorporeal bypass of the portal and vena caval blood unnecessary during anastomosis of the vessels. The hemodynamic state was stable both during the operation and early postoperative period. Furthermore, this method may prevent the functional competition between the graft and host liver.