THE ROLE OF THE SPLEEN IN PANCREAS TRANSPLANTATION

Early graft thrombosis and rejection of the graft are the two major ca uses of graft failure in pancreas transplantation. Inclusion of the sp leen in the pancreatic graft has been purported as a possible solution to both complications, but severe graft-versus-host disease led to ab olishment of this procedure. By irradiating the donor spleen ex vivo d uring cold storage, we successfully prevented graft-versus-host diseas e, allowing us to evaluate the advantages of clinical pancreaticosplen ic transplantation. This study reports our experience with 12 pancreat icosplenic transplantations. Using Doppler flow measurements, we have been able to examine the hemodynamic advantages. Our results confirm t he purported benefit. Vascular resistance indices in the pancreatic gr aft are significantly lower when the donor spleen is included. This, h owever, did not lower the incidence of thrombosis (2 out of 12 cases) in our study. Serial radionuclide studies with Tc-99m-hexamethyl propy lene amine oxime were performed for further evaluation of graft perfus ion. With time the spleen uptake diminishes, compatible with atrophy o f the organ. This was confirmed histologically. No indication of an im munologic advantage of transplanting the pancreas together with the sp leen was found. All patients went through severe rejection crises. A t ransient reduction in platelet count (55-88%, mean 71%) of preoperativ e values was observed. This platelet drop is not seen in patients with a pancreas without spleen transplantation. We conclude that in pancre as transplantation, inclusion of the irradiated spleen has no obvious advantages for early graft thrombosis and rejection of the graft.