Strategies for successful endoscopic submucosal dissection in difficult conditions of the upper gastrointestinal tract.

Endoscopic submucosal dissection (ESD) is a useful method for the treatment of early cancers of the esophagus and stomach. Difficulty during gastric ESD increases the risk of local recurrence or severe complications, with risk factors including an upper gastric location, large lesions (>20 mm), submucosal cancer, and fibrotic lesions. Various types of electrosurgical knives with advanced functions have been developed, and image-enhanced endoscopy provides more accurate information for tumor assessment. Under certain conditions, the endoscopic approach to ESD can be challenging and may result in poor resection outcomes. Clip traction, changes in patient positioning, air deflation, and precise dissection can be effective options, depending on the circumstances. The pocket creation method is useful for resecting large lesions in the esophagus and stomach. Severe fibrotic lesions may require endoscopic subserosal dissection when located in the cardia, or along the lesser or greater curvature of the stomach. In addition, gastric peroral endoscopic myotomy can overcome anatomical obstacles in some cases.