N-acetylcysteine for the prevention of stricture after circumferential endoscopic submucosal dissection of the esophagus: a randomized trial in a porcine model

Two groups of six pigs each were subjected to general anesthesia and CESD: after randomization, a first group received an oral NAC treatment regimen of 100 mg/kg/day, initiated one week before the procedure, whereas a second group was followed without any prophylactic treatment. Follow-up endoscopies took place seven, fourteen, twenty-one, and twenty-eight days after CESD. Necropsy, histological assessment of esophageal inflammation, and fibrosis were performed on day 28.The median esophageal lumen diameter on day 21 (main judgment criterion) was 4 mm (range 2 to 5) in group 1 and 3 mm (range 1 to 7) in group 2 (P？=？0.95). No significant difference was observed between the two groups regarding clinical evaluation (time before onset of clinically significant esophageal obstruction), number of dilations, esophageal inflammation and fibrosis, or oxidative stress damage on immunohistochemistry.Despite its antioxidant effect, systemic administration of NAC did not show significant benefit on esophageal fibrosis in our animal model of esophageal wound healing within the experimental conditions of this study. Since the administered doses were relatively high, it seems unlikely that NAC might be a valuable option for the prevention of post-endoscopic esophageal stricture.Endoscopic resection of Barrett’s esophagus with a high-grade dysplasia or early esophageal cancer has become an acceptable therapeutic option [1-3], alongside surgical esophagectomy. Endoscopic mucosal resection is easily feasible but leads to a piecemeal, non-carcinologic resection of neoplastic tissue, whereas endoscopic submucosal dissection (ESD) is more carcinologically efficient, although more technically challenging. Nonetheless, both techniques result in cicatricial fibroinflammatory esophageal strictures when 75% or more of the mucosal circumference is removed [4,5]. These strictures may require numerous endoscopic dilations, jeopardizing the patients’ quality of life and risking esophageal perfor