Endoscopic submucosal dissection for early esophageal cancer associated with achalasia - OHKURA, Yu; IIZUKA, Toshiro; KIKUCHI, Daisuke; YAMASHITA, Satoshi; NAKAMURA, Masanori; MATSUI, Akira; MITANI, Toshifumi; HOTEYA, Shu; KAISE, Mitsuru; YAHAGI, Naohisa (Turkish Journal of Gastroenterology, 2013)