Absorption studies using portal anastomotic veins.

In man the portal circulation, being without major and macroscopic connection with systemic veins, has been hidden from the clinical investigator. Even the intravascular catheter has not invaded the duplex circulations feeding the liver, but only its drainage system. Thus circulatory inaccessability of the key digestive gland in man has left it mysterious, a metabolic sphinx. Surgeons, deleting the spleen from persons with portal hypertension, have recorded sporadic data on portal pressure and blood gases (1, 2). Physiologists have estimated total hepatic blood flow in man by the bromsulphalein clearance test (3) which permits at least reasonable approximations. Sherlock and Walshe (4) added some facts by measuring portal blood from large superficial anastomotic veins in a single patient with cirrhosis. They reported observations in a patient with a large abdominal vein apparently draining blood from the upper segment of the alimentary canal into the right great saphenous vein. Their attention was concentrated on a comparison of systemic and anastomotic blood levels of glucose, galactose, fructose, fat and nitrogen at appropriate intervals after ingestion of measured quantities of these substances or their precursors, singly or in combination. The ordinary collateral veins over the abdomen of cirrhotic patients have been studied in an effort to determine portal pressures (1, 5) and circulation time (6). Billings and DePree suggested that comparison of blood from the abdominal collaterals and systemic veins following administration of glucose orally might permit the differentiation of cirrhosis from other disorders giving rise to collateral vessels over the belly (7).