Xenogeneic direct hemoperfusion using whole swine liver for liver failure in dogs

Abstract

Background. We developed a new method of xenogeneic direct hemoperfusion of a bioartificial liver support system consisting of a leukocyte-adsorbent column, an immunoglobulin-adsorbent column, and the substitute unit for hepatic function. By this method, we performed xenogeneic direct hemoperfusion experiment using resected whole swine liver for treatment of a canine liver failure model, and compared the contribution of each adsorbent column both by blood analysis and from the histological point of view. Materials and methods. Canine liver failure model was produced by portocaval shunting and ligating the entire hepatoduodenal ligament. The xenogeneic direct hemoperfusion system was constructed using a roller pump, a leukocyte-adsorbent column, an immunoglobulin-adsorbent column, a combined device of oxygenator and warmer, the resected whole swine liver accommodated in a chamber, and a dissolved oxygen meter through which canine whole blood leaving the external jugular vein circulated in this order. Results. Xenogeneic direct hemoperfusion was successfully performed for 3 h without hyperacute rejection occurring. Adequate ammonia detoxification and bile juice secretion were exhibited, and no findings of hepatocyte destruction by immunological cells and proteins were detected. Blood data showed that the immunoglobulin adsorbent were more effective than the leukocyte adsorbent in avoiding hyperacute rejection. This result indicates that hyperacute rejection has a closer relation to humoral immune responses, especially regarding removal of complements than to cellular immune responses. Conclusions. We successfully performed xenogeneic direct hemoperfusion of the whole swine liver without hyperacute rejection using our method.