Salvage endoscopic submucosal tunneling dissection using an electrosurgical knife for an elderly patient with circumferential residual esophageal squamous cell carcinoma after radiotherapy - Mai Ego, MD; Seiichiro Abe, MD, PhD; Shih Yea Sylvia Wu, MD; Ichiro Oda, MD; Yutaka Saito, MD, PhD (VideoGIE, 2020)