Endoscopic Submucosal Dissection, a New Technique for en Bloc Resection of Large Superficial Tumor in the Esophagus

For superficial esophageal cancer, conventional endoscopic mucosal resection with cap (EMRC) has been widely prevailed for reliable and safety treatment1. Recent innovations of diagnostic endoscopy including high-resolution endoscopy, narrow band imaging (NBI), and magnified endoscopy allow detect and identify more small lesions of the GI tract, and endoscopist are forced to develop their skills for endocopic treatment. Recently, endoscopic submucosal dissection (ESD) has been developed for en bloc resection of larger superficial tumor in the GI tract than conventional EMR. In this decade, ESD has been widely accepted as a more reliable therapeutic procedure than EMR in Japan, and various devices are developed. Of the esophageal cancers, squamous cell carcinoma is the most common carcinoma in Japan, and iodine staining endoscopy has been widely used to detect esophageal SCC. Conventional EMRC has been performed for these 10 years, however, since conventional EMRC were carried out with small size cap, 12mm in diameter, there has been the risk to be piecemeal and residual lesions. Recently, newly classification of intrapapillary capillary loop pattern (IPCL) has developed for diagnose the early esophageal neoplasm, and because of these diagnostic innovation, therefore, many endoscopist are forced to remove larger en bloc resection for reliable ESD as well as gastric or colorectal lesions. Therefore, in Japan, ESD for large superficial esophageal neoplasm has been applied; however, esophageal ESD is considered as more difficult and challenging than gastric ESD, and only few studies have elucidated the technical feasibility of ESD in the esophagus. Needle knife has been used for early gastric and colorectal ESD, and it has been considered causing high complications for esophageal ESD because of its sharpness. For this reason, using other knives, some clinical case series are reported for esophageal ESD, and the safety of esophageal ESD using needle knife is still unclear. In this study, we conducted consecutive esophageal ESD with needle knife and compared EMR to evaluate safety and reliability of needle knife as esophageal ESD device.