Endoscopic submucosal dissection using sodium hyaluronate, a new technique for en bloc resection of a large superficial tumor in the colon.

En bloc resection of superficial tumors in the colon is challenging but beneficial for the precise diagnosis and treatment. We have been using a novel technique of endoscopic submucosal dissection with a viscous substance, sodium hyaluronate, and a needle knife in combination with a small-caliber-tip transparent hood and succeeded in the endoscopic en bloc resection of large superficial tumors in the colon. We endoscopically treated superficial tumors larger than 20mm in diameter of the colon in 166 patients between June 1998 and March 2005. All the lesions were successfully resected endoscopically and en bloc resection was achieved in 77% of them. Even large superficial tumors in the colon can be resected in one piece by using this technique.