Abstract
Objective: Gastric cancer is one of the most common cancers in Japan. Advances in esophagogastroduodenoscopy (EGD) have enabled minimal changes in gastric mucosa due to early stage cancer to be detected but opaque gastric mucus covering the surface of gastric lesions hampers precise observation of microlesions. Pronase is able to remove this opaque mucus, providing a clear view of microlesions, so it has been used for a long time as premedication in EGD. Because pronase is activated at neutral to alkaline pH, sodium bicarbonate is added to the pronase solution. However, as measuring the prescribed quantity of sodium bicarbonate each time on the day of EGD is time-consuming, alkali-ion water is used instead of a sodium bicarbonate solution.
Methods: The activity and stability of pronase dissolved in alkali-ion water were assessed in vitro. In vivo, 406 patients were examined using EGD and divided into 4 groups according to the preparation administered, namely pronase in alkali-ion water or sodium bicarbonate solution, alkali-ion water alone, or purified water alone. The degree of opacity of mucus was compared among the 4 groups.
Results: Pronase solution in alkali-ion water removed gastric mucus to a similar degree to pronase in sodium bicarbonate solution. No adverse effects related to the use of pronase in alkali-ion water were observed.
Conclusion: The use of alkali-ion water to dissolve pronase was considered a simple and effective means for achieving precision in EGD.
