Rheologic analysis of gastric mucosal hemodynamics in patients with cirrhosis

Portal hypertensive gastropathy causes some gastric mucosal microcirculatory disorders in cirrhotic patients, but the nature of the rheologic dysfunction in the gastric microcirculation remains to be clarified.

To examine the rheologic properties of the gastric microcirculation, we subjected 112 cirrhotic patients and 51 control subjects to endoscopic laser Doppler flowmetry and measured multiple variables of flow, red blood cell volume, and velocity. Furthermore, based on these results, we analyzed the shear rate which reflects the status of the microcirculatory system. To validate the laser Doppler flowmetry, we derived the relationship between red blood cell volume and cross-sectional areas of submucosal collecting venules; near-infrared endoscopy was used to evaluate this relationship.

Analysis of shear rate according to the severity of portal hypertensive gastropathy showed that the mucosa was exposed to strong hemokinetic stress in severe cases, characterized by a higher shear rate than in control subjects or in mild cases. Nitroglycerin, administered by intravenous infusion (1.0 microg/kg/min), reduced blood flow and restored shear rate to control levels in patients with severe portal hypertensive gastropathy.

This rheologic study of the gastric mucosa suggests that a disorder of the shear rate control mechanism in the microcirculation is associated with severe portal hypertensive gastropathy.