LAUSR

LOCAL STEROID INJECTIONS are widely used for stricture prevention after esophageal endoscopic submucosal dissection (ESD). Animal studies show some potential risks of steroid therapy, such as atrophy of the muscularis propria and perforation during healing of ESD ulcer. Moreover, cases of delayed perforation after locoregional steroid injection due to muscularis propria injuries have previously been reported. Endoscopists are required to inject steroids into the thin layer of remnant submucosal tissue without injuring the muscularis propria. A 63-year-old man with superficial esophageal cancer was referred to our hospital (Shizuoka Cancer Center) for endoscopic treatment. A 45-mm 2/3 circumferential lesion was identified on the anterior wall of the middle thoracic esophagus (Fig. 1a,b). We achieved en bloc resection by ESD without adverse events. During post-ESD ulcer inspection, only a thin layer of submucosal connective tissue remnants was observed (Fig. 1c). As the conventional topical steroid injection method could damage the muscularis propria, we decided to inject steroids using the “stamping” method (Video S1). After release of an injector catheter into the esophageal lumen, we attached the tip of the catheter onto the muscularis propria surface and injected 10-mL saline solution containing 100 mg triamcinolone acetonide (Kenacort-A; Bristol-Myers Squibb, New York, NY, USA) into the residual submucosal tissue without a needle opening. This technique created a submucosal cushion without damaging the muscularis propria (Fig. 2a). Nine weeks after the procedure, normal-appearing post-ESD scar was observed without stenosis formation (Fig. 2b). The stamping method using only a needle catheter without a needle opening avoids the risks of intramuscular