Wang W.-L.Chang I.-W.CHIEN-CHUAN CHENChang C.-Y.Tseng C.-H.Tai C.-M.Lin J.-T.HSIU-PO WANGLee C.-T.2021-01-152021-01-1520182050-6406https://www.scopus.com/inward/record.uri?eid=2-s2.0-85041575781&doi=10.1177%2f2050640618755236&partnerID=40&md5=fca1f0e29a5672b675f677d52b78ce02https://scholars.lib.ntu.edu.tw/handle/123456789/540927Background: Endoscopic radiofrequency ablation (RFA) is a rapidly evolving therapeutic modality for early flat esophageal squamous cell neoplasms (ESCNs). However, the in?vivo tissue effects of RFA on the esophageal wall are uncertain. Methods: We prospectively enrolled eight patients with flat-type early ESCNs who were treated with balloon-based RFA. We evaluated the in?vivo tissue effect on the esophagus using endoscopic ultrasound (EUS) and the histology of retrieved coagulum. Results: The mean tumor length was 6.1 cm, and six of the eight patients achieved a complete response after primary RFA. Real-time evaluation of the tissue effect showed that the mucosa and submucosal layer were more edematous and thicker after RFA than before the procedure (mean 4.89 vs. 2.04 mm, p<.001), suggesting that the thermal effect of RFA may injure the submucosa. Histological evaluation of retrieved coagulum showed a severe cauterization (burning) effect with extensive cell necrosis; however, four cases had some residual viable neoplastic cells. Even though there were viable cells in the sloughed coagulum, half of the patients still achieved complete remission after RFA. Conclusions: Our findings suggest that the thermal effect of RFA may injure the submucosal layer and enable neoplastic epithelium to slough off without “burning.”. ? 2018, Author(s) 2018.[SDGs]SDG3adult; argon plasma coagulation; Article; cancer tissue; cell death; clinical article; computer assisted tomography; dysphagia; dysplasia; endoscopic mucosal resection; endoscopic ultrasonography; esophageal squamous cell carcinoma; follow up; histology; human; human tissue; male; mucosa; odynophagia; priority journal; radiofrequency ablation; sore throat; submucosa; thorax painjournal article10.1177/20506406187552362-s2.0-85041575781