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Biomedical subjects

Hirohumi Niwa

Publications and source records attributed to Hirohumi Niwa.

4 recordsLinked to original sources

Safer endoscopic gastric mucosal resection: preoperative proton pump inhibitor administration.

BACKGROUND AND AIM: Control of bleeding is crucial in improving the safety of endoscopic mucosal resection (EMR), and intragastric acidity has a great impact on hemostasis and blood coagulation. Proton pump inhibitors (PPI) are potent suppressors of gastric acid; however, PPI need to be continuously administered orally for several days, and thus initial effects may be insufficient if PPI is only administered immediately after EMR. The aim of this study was to determine whether preoperative administration of PPI prior to EMR can elevate intragastric acidity, facilitate better control of intraoperative bleeding (complete coagulation and hemostasis), prevent postoperative bleeding, and facilitate healing of artificial ulcers. METHODS: A randomized clinical study was conducted in which EMR was performed with or without 1 week of preoperative PPI administration. RESULTS: Artificial ulcers created by EMR healed more rapidly in patients who received preoperative PPI. CONCLUSIONS: The results of the study suggest that preoperative administration of PPI before EMR is useful for controlling and preventing bleeding, and for facilitating the healing of artificial ulcers.

Adenoma↗

Clinical usefulness of a new infrared videoendoscope system for diagnosis of early stage gastric cancer.

BACKGROUND: Infrared light can penetrate tissue more deeply than visible light. Therefore, an infrared video endoscope may be useful for assessment of gastric submucosal vessels. However, the resolution of currently available infrared video endoscope systems has been unsatisfactory. A new infrared video endoscope system was developed and its clinical utility assessed for diagnosis of early stage gastric cancer. METHODS: Twenty-five patients with early stage gastric cancer and 8 with gastric adenoma underwent endoscopy with the infrared video endoscope system after intravenous injection of indocyanine green. RESULT: Indocyanine green pooling did not appear in adenomas and some intramucosal gastric cancers, whereas it was noted in all submucosally invasive gastric cancers. Tumors not exhibiting indocyanine green pooling were intramucosal, well-differentiated adenocarcinomas of low height (flat-type cancers). CONCLUSION: These results suggest that our new infrared video endoscope provides valuable information about the submucosal aspect of early stage gastric cancer. Infrared video endoscopy may become a powerful technique for determining whether to perform endoscopic mucosal resection.

Adenoma↗