The surgery of portal hypertension.

The renewed interest which has taken place during the past half decade in the relief of portal hypertension by surgical means has called for precise methods of diagnosis, both of the cause and of the degree of portal hypertension. Knowledge of the normal variations in the portal blood pressure in man is still inadequate, and it is probable that an elevation considerably above the normal can occur without any deleterious effects, for in all patients who show clinical evidences of the condition, the figure, when measured, is found to be well above that commonly found in patients on whom an abdominal operation is being performed for some other condition. In practice it is rare to find a patient in whom the portal hypertension does not affect the whole of the portal system and the surgical treatment discussed here refers only to such cases. The obstruction is either in the liver itself, the result of cirrhosis of the liver, or of thrombosis of the portal vein. The effects are identical, but in the case of cirrhosis not only are the effects of the portal hypertension evident, but also the effects of the disturbed liver function. The cases in which there is thrombosis of the portal vein are mainly of congenital origin, and haematemesis is the only symptom; the first attack occurs during the early years of life and, if untreated, this bleeding is eventually fatal. The liver in such cases is normal both on gross examination and histologically, but it is these patients who have the highest portal pressure, usually over 400 mm. of water and, as this bleeding from oesophageal varices is the only source of danger, all possible steps to prevent it should be considered. The normal portal pressure is about ioo mm. of water, and readings above 150 mm. must be considered excessive. In the case of cirrhosis of' the liver we have found readings up to 360 mm. and, in congenital obstruction to the portal vein, up to 490 mm., while other observers have recorded even higher readings. It is important to emphasize. that the degree of ascites bears no relation to the portal venous pressure and, if the liver is normal histologically, ascites is never present. Diagnosis