We used an endoscope with a water-jet system (PCF-Q260J; Olympus). When scope operability was poor because of the paradoxical movement or adhesion, a balloon-assisted endoscope with a hydrophilic-coated silicone splinting tube (ST-CB 1; Olympus) was used
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. A short-type small-caliber-tip transparent hood (Fujifilm; Tokyo, Japan) was placed on the endoscopic tip. For all the cases, we used carbon dioxide for insufflation, and the electrosurgical unit was ESG-100 (Olympus). We used a dual knife (KD650Q; Olympus), and ESD was performed under conscious sedation, using intravenous midazolam (1–3 mg), pethidine hydrochloride (35 mg), or both. Submucosal injection of hyaluronic acid solution mixed with a small amount of indigo carmine and 0.1 % epinephrine (1 mL of 0.1 % epinephrine in 9 mL of indigo carmine solution = 1:100,000 injectate) was applied. After injection into the submucosal layer, we alternately performed the partial circumferential incision (“Pulse cut slow" mode [30 W]) and the subsequent submucosal dissection (“Forced coagulation” mode [30 W]). We performed all the ESD procedures as described in the previous study
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.
