Chinese Medical Journal

44 THE CHINESE MEDICAL JOURNAL

a. In cases of demonstrable esophageal varices the incidence of hematemesis was 35.1 per cent and in those where X-ray examination failed to show any evidence of esophageal varices hematemesis occurred in 17.4 per cent of the cases. This might be due to the fact that the varices present were of a mild degree or they were located in the gastric wall below the cardiac end. Both these conditions were difficult to detect by the present methods of x-ray examination.

b. The incidence of esophageal varices, like that of hematemesis, _ was higher in the extrahepatic group. We consider that when the ob-

struction is in the extrahepatic portion of the portal bed, especially when it is in the splenic vein, the collateral channels are much fewer than when the obstruction occurs in the liver. The esophageal veins practically constitute the main diverting pathway of that part of the portal blood flow. Therefore, marked engorgement of these veins with varices formation is usually present.

8. Portal pressure. The portal pressure was determined through the epiploic branches during operation in 50 cases. The readings taken were based on the height of the blood column from the level of the cannulated vein. As only a relative rise or fall of the pressure is of importance, we usually did not take the level of the portal vein as the basal line. The results are shown in Table 12.

Table 12. Portal pressure as determined during operation

Portal pressure Pe ; : Above No. of (mm in blood 150-200 201-300 301-400 400 Gacee

ess than 150

column) Intrahepatic 6 Wis 14 10 6 43 Extrahepatic 1 3 2 1 iG SSS eS Total 6 8 17 12 Mf 50

No obvious difference in portal pressure was found between the intrahepatic and extrahepatic groups. In 6 cases, the pressure was below 150 mm but congestive splenomegaly was present in all of them and the diagnosis of portal hypertension was made before operation. The diagnosis of portal hypertension was established despite the low pressure for the following reasons: 1. The increased portal pressure might have been buffered by the enlarged spleen and the established collaterals, Inasmuch as evident esophageal varices were found in 2 of them. 2. In measuring the portal pressure through the epiploic branches of 10 laparotomy cases without clinical manifestations of portal hypertension, we found that the average value was 99.4 mm blood column. The