LAUSR

A 74-year-old man complained of trismus and was diagnosed with advanced pharyngeal cancer. A preoperative ultrathin endoscopy detected a superficial esophageal tumor, 30mm in diameter, at the upper thoracic esophagus. The patient followed a liquid diet completely owing to his restricted mouth opening. Consequently, a percutaneous endoscopic gastrostomy was performed to ensure sufficient nutrition. Chemoradiotherapy was directed toward the pharyngeal cancer and not the esophageal cancer to avoid a larger radiation field leading to complications. However, trismus persisted even after chemoradiotherapy, following which endoscopic submucosal dissection (ESD) was planned for the esophageal cancer. First, balloon dilation was performed under vision by transnasal endoscopy (▶Fig. 1). An endoscope (8.9mm diameter, GIF-H290; Olympus, Tokyo, Japan) was inserted through the gastrostomy (▶Video 1), and the tip of the transnasal endoscope was positioned just below the esophagogastric junction (▶Fig. 2). We then proceeded with endoscopy to the esophageal lumen, and a circumferential marking was made (▶Fig. 3). After making an oral mucosal incision using the endoscope through the gastrostomy, both circumferential incision and subsequent submucosal dissection were performed until the tumor was resected en bloc (▶Fig. 4) using a clip with line attached to the anal side of the specimen and pulled through the gastrostomy for appropriate tension [1]. During the procedure, gas insufflated into the stomach was suctioned periodically to relieve the patient’s pain and prevent Mallory-Weiss syndrome, particularly when an ESD knife was placed in the esophageal lumen to make reinsertion into the esophageal lumen through the esophagogastric junction easier (▶Fig. 5). ESD using ultrathin endoscopy is reportedly useful [2, 3]; however, endoscopic maneuverability is restricted. Moreover, the current device options are limited due to the availability of a small instrumentation channel. While a previous E-Videos