A randomized clinical trial for the efficacy and safety of local steroid injection for prevention of post-ESD esophageal stenosis

INTERVENTION: Local steroid injection (Triamcinolone Acetonide) after ESD No treatment after ESD CONDITION: Early esophageal cancer PRIMARY OUTCOME: The proportion of patients who need endoscopic dilatation for post‐ESD esophageal stenosis SECONDARY OUTCOME: 1. The frequency of the complication with local steroid injection; 2. The frequency of the complication with endoscopic dilatation INCLUSION CRITERIA: Patients with superficial squamous cell carcinoma whose mucosal defect after ESD is expected to be over three‐fourths of the whole circumference (being highly associated with post ESD stenosis)