The changes in blood coagulation/fibrinolysis and intestinal microvasculature after acute portal vein occlusion were studied in adult mongrel dogs. All five dogs that underwent portal vein
ligation with resultant portal system
thrombosis died within 81-130 min following the procedure.
Fibrin deposition occurred in the small-intestine mucous-membrane capillaries within 10 min after
ligation. Before
ligation, high levels of
tissue plasminogen activator activity were noted in small vessels, mainly those of the small-intestine submucosa. However, this activity decreased significantly after portal vein
ligation, suggesting progression into irreversible
disseminated intravascular coagulation. After simultaneous portal vein and superior mesenteric artery occlusion, similar changes occurred, but later than with portal vein
ligation alone. The five dogs who underwent this procedure died within 70-195 min. However, if portal blood was bypassed into the femoral vein through an anti-thrombogenic heparinized hydrophilic
catheter, deterioration after complete portal vein
ligation was not observed; the five dogs that underwent this procedure survived.