Risk factors for haemorrhage from oesophageal varices and acute gastric erosions.

Rupture, versus erosion, is the most likely cause of variceal bleeding. The risk of rupture appears to be enhanced in large varices and varices with reddish discoloration. Incompetent perforating veins connecting varices to deeper venous systems may also be important in the pathogenesis of this event. Perhaps one-third of patients with large varices will bleed from them over a period of one to two years. Portal hypertension cannot be used to predict the future risk of bleeding among groups of patients. Nevertheless, it is possible that increases or decreases in portal pressure in individual patients may alter their bleeding risk. We and others have observed portal pressure as low as 10 mmHg in patients with clear-cut, recurrent variceal bleeding. Portal hypertension probably predisposes to gastric mucosal injury by enhancing, by an undefined mechanism, back-diffusion of acid. Consequently, haemorrhagic gastritis is more common in patients with portal hypertension than those without. Whether haemorrhagic gastritis is a more severe lesion in patients with portal hypertension is unclear.