Use of N-acetylcysteine plus simethicone to improve mucosal visibility in upper digestive endoscopy via systematic alphanumeric-coded endoscopy: a randomized, double-blind controlled trial

Background The use of antifoaming and mucolytic agents prior to upper gastrointestinal (GI) endoscopy and a thorough systematic review are essential to optimize lesion detection. This study evaluated the effect of simethicone and N-acetylcysteine on the adequate mucosal visibility (AMV) of the upper GI tract by an innovative systematic method. Methods This randomized, double-blind controlled trial included consecutive patients who underwent diagnostic upper GI endoscopy for screening for early neoplasms between August 2019 and December 2019. The upper GI tract was systematically assessed by systematic alphanumeric-coded endoscopy. Patients were divided into 4 groups: 1) water; 2) only simethicone; 3) N-acetylcysteine + simethicone; and 4) only N-acetylcysteine. The following parameters were assessed in each group: age, sex, body mass index, level of adequate mucosal visibility, and side-effects. Results A total of 4564 images from upper GI areas were obtained for evaluation. The mean AMV in the 4 groups was 93.98±7.36%. The N-acetylcysteine + simethicone group had a higher cleaning percentage compared with the other groups (P=0.001). There was no significant difference among the remaining groups, but several areas had better cleaning when a mucolytic or antifoam alone was used. No side-effects were found in any group. Conclusion The combination of N-acetylcysteine plus simethicone optimizes the visibility of the mucosa of the upper GI tract, which could potentially increase diagnostic yield.