[Arterial and portal circulatory compensation in hepatic artery occlusion]

The hepatic artery occlusion is compensated for the opening of pre-existing arterial anastomosis which divert the blood in to arteries downstream of the stenosis for the increase of the flow and for the portal oxygenation. The entity and the type of the collateral circulation depend on the site on the extent on the entity on the rapidity of the development and eventually on the patency of the main pre-existing anastomotic arteries. This circulation is more effective of the stenosis is in the common hepatic artery whereas it becomes more and more uneffective when the occlusion concerns the peripheral arterial branches. The increase of the portal flow occurs mainly through the splenic circulation or with the celiac trunk stenosis and in the splenectomised patients or through the mesenteric circulation thanks to a neuro-humoral mechanism which causes the opening of the precapillary arteriovenous communications. The increase of the portal flow is in correlation with the hypoxia of the hepatocyte for the decreased sinusoidal arterial supply.