Rheologic analysis of gastric mucosal hemodynamics in patients with cirrhosis

Background: Portal hypertensive gastropathy causes some gastric mucosal mic rocirculatory disorders in cirrhotic patients, but the nature of the theolo gic dysfunction in the gastric microcirculation remains to be clarified. Methods: To examine the rheologic properties of the gastric microcirculatio n, we subjected 112 cirrhotic patients and 51 control subjects to endoscopi c laser Doppler flowmetry and measured multiple variables of flow, red bloo d cell volume, and velocity. Furthermore, based on these results, we analyz ed the shear rate which reflects the status of the microcirculatory system. To validate the laser Doppler flowmetry, we derived the relationship betwe en red blood cell volume and cross-sectional areas of submucosal collecting venules; near-infrared endoscopy was used to evaluate this relationship, Results: Analysis of shear rate according to the severity of portal hyperte nsive gastropathy showed that the mucosa was exposed to strong hemokinetic stress in severe cases, characterized by a higher shear rate than in contro l subjects or in mild cases. Nitroglycerin, administered by intravenous inf usion (1.0 mu g/kg/min), reduced blood flow and restored shear rate to cont rol levels in patients with severe portal hypertensive gastropathy. Conclusion: This theologic study of the gastric mucosa suggests that a diso rder of the shear rate control mechanism in the microcirculation is associa ted with severe portal hypertensive gastropathy.