Why portal hypertensive varices bleed and bleed: a hypothesis.

Continued bleeding or early rebleeding is associated with a poor prognosis in patients with variceal haemorrhage. It is not clear why bleeding stops in some patients and continues or restarts in others. It is suggested that secondary haemodynamic changes in the splanchnic circulation after a bleed may contribute to the risk of further bleeding. These changes include the effects of hypotension on portocollateral resistance, the effects of blood in the gut on splanchnic blood flow, and the effects of blood volume expansion on portal venous pressure during resuscitation. These factors, working in concert, cause a secondary rise in portal venous pressure, which may precipitate further bleeding. Treatment aimed at preventing these secondary haemodynamic changes may be beneficial. It is probable that somatostatin and octreotide could act in this way, which may explain their therapeutic efficacy.