The in vivo tissue effect of endoscopic balloon‐based radiofrequency ablation in treating esophageal squamous cell neoplasia

Abstract

Endoscopic radiofrequency ablation (RFA) is a rapidly evolving therapeutic modality for early flat esophageal squamous cell neoplasms (ESCNs). However, the invivo tissue effects of RFA on the esophageal wall are uncertain. We prospectively enrolled eight patients with flat-type early ESCNs who were treated with balloon-based RFA. We evaluated the invivo tissue effect on the esophagus using endoscopic ultrasound (EUS) and the histology of retrieved coagulum. 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. Our findings suggest that the thermal effect of RFA may injure the submucosal layer and enable neoplastic epithelium to slough off without "burning."