Experimental production of portal hypertension in dogs by a whole liver compression.

In spite of many attempts to produce an experimental model for studying the pathogenesis and the pathophysiology of portal hypertension and esophageal varices, satisfactory results have not been reported. Since most attempts involved multiple operations or complicated surgical maneuvers to achieve portal hypertension, experimental animals could not survive easily. This new procedure requires only a simple operation, so experimental animal survival is high. The portal venous pressure can be raised immediately by increasing intrahepatic vascular resistance. This is done by wrapping and compressing the whole liver with polypropylene mesh, which also prevents the development of hepatopetal collaterals. The experimental production of portal hypertension in fifteen dogs resulted in only one death. The remaining fourteen dogs were in good condition for nine weeks after the operation and were maintaining elevated ranges of portal pressure with an average of 326 mmH2O. Varying degrees of esophageal venous dilatation were evident. Based on the results, this newly developed method seems to be useful for studying the pathophysiology of the portal hypertension and esophageal varices.