Using 9-12-month-old Lewis rats, our laboratory performed consecutive organ transplantations to assess the technical feasibility and observe the histopathologies of prolonged transplants and implants over a rat's life span. This study includes a total of 688 cases of consecutive syngeneic organ transplantation, including pancreaticoduodenum (PD), en-bloc liver-pancreaticoduodenum-spleen-stomach (LPdSpSt), and spleen bearing ovary or testicle. A 52-month-old consecutively transplanted pancreas showed normal acini and islet cells. Consecutively transplanted LPdSpSt cases at 25-28 months preserved normal histology. After 26.5 months of ovarian follicle implantation into the spleen, the pathology of the organ exhibited typical dysgerminoma. However, 29.5-month-old infantile testicle implants in the spleen showed seminoma. Our studies suggest that transplanted organs can be reusable and retransplanted, and we hope this could be one of the clues to solve donor-organ shortages in the future.

Comparison of pancreaticoduodenal transplants (PDT) and duct-ligated pancreas transplant (DLPT) were performed using syngeneic and allogeneic studies in rats. Both DLPT and PDT allogeneic grafts showed mild rejection. DLPT groups showed disorganized pathology and acini replaced by fat. Eventually, massive fibrosis was seen in the Islets of Langerhans, as well as rejection cellular infiltrates. In both PDT groups, normal histology was observed in the same period. Thus the effect of duct occlusion is highly detrimental for the grafts.