Simultaneous analysis of mucosal and submucosal hemodynamics using infrared electronic endoscopy: effects of intraluminal acid on ulcer scars.

BACKGROUND AND STUDY AIMS

This report describes the use of an infrared electronic endoscope for the assessment of gastric mucosal and submucosal hemodynamics in ulcer scars.

METHODS

The experimental ulcer scars were induced by acetic acid injection in five anesthetized dogs. Indices of mucosal hemoglobin content (IHb) and its oxygenation (ISO2) were calculated from reflectance spectra of the mucosa at 569, 577, 586, and 650 nm, which were obtained through an optic probe. The gastric submucosal vascular diameter was assessed by comparison with a reference wire under infrared endoscopic observation.

RESULTS

The index of mucosal hemoglobin content measured by reflectance spectrophotometry was significantly higher at the ulcer scars than in the intact mucosa before the ulcer induction. Intraluminal administration of 0.2 N hydrochloric acid lowered IHb and ISO2 only at the ulcer scars. The diameters of the gastric submucosal veins beneath the ulcer scars decreased markedly after the acid administration.

CONCLUSION

The results suggest abnormal responses of gastric mucosal and submucosal circulation at ulcer scars to intraluminal acid. Infrared electronic endoscopy is therefore a useful tool for the simultaneous analysis of mucosal and submucosal circulation in the stomach.