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. (Gastrointest Endosc 2003;57:336-42.)