A patient undergoing subtotal pancreatectomy and intraportal islet tissue autotransplantation for chronic pancreatitis developed severe portal hypertension (49 cm of H(2)O) and acute disseminated intravascular coagulation (DIC). In an attempt to identify the cause of these problems, portal pressure and the activities of the coagulation and fibrinolytic systems were studied in dogs undergoing intraportal autotransplantation of islet tissue. Following intraportal injection of the pancreatic tissue in five control dogs, the portal pressure rose to a maximum of 43.2 cm of H(2)O +/- 2.4 and major coagulation abnormalities occurred. The mean hematocrit value fell to 18% +/- 8.6, the mean platelet count to 218,000 +/- 31,000, the mean plasma fibrinogen to 40 mg/dl +/- 18, and the mean euglobulin clot lysis time (ECLT) to 25 min +/- 4. Partial thromboplastin time (PTT) became prolonged (233 secs +/- 30) and significant quantities of fibrinogen-fibrin degradation products (FDP-fdp) (1:128 +/- 32) appeared. These changes indicate the development of DIC probably secondary to significant amounts of tissue thromboplastin detected in the tissue homogenate infused at time of autotransplantation. In a group of seven dogs in whom heparin and Trasylol (aprotinin) were added to the pancreatic tissue at the time of transplantation, portal pressure rose only to a peak of 28.3 cm of H(2)O +/- 3.6 and no significant abnormalities occurred in mean hematocrit value, plasma fibrinogen, platelet count or ECLT. Minor prolongation of PTT occurred secondary to the activity of heparin. FDP-fdp (1:16) were present transiently during tissue injection. Four patients in whom heparin and Trasylol were added to the pancreatic tissue at the time of autotransplantation developed only minor elevations of portal pressure (mean 15.5 cm of H(2)O) without intravascular coagulopathy.