Iodine staining with distance countdown improving the safety for reduction of adverse events: a randomized controlled trial.

Background: Lugol's chromoendoscopy (LCE) is valuable, cost-effective, and widely used in early esophageal cancer (EEC) screening, yet it suffers from low compliance due to adverse events after LCE. In addition, the reflux of iodine during iodine staining in the upper esophagus brings the risk of bucking and aspiration. We introduced a new model called distance countdown (DC) aimed to reduce reflux during iodine staining in upper esophageal LCE.

Methods: In this randomized controlled trial (RCT), 204 patients were randomized into the DC and No-DC groups. The primary endpoint was the difference in the incidence of positive starch reagent reaction (iodine solution reflux) between the two groups. The secondary endpoints were the comparisons of the incidence of other adverse events following LCE between the two groups.

Results: The rate of iodine solution reflux was 1.0% in the DC group and 26.5% in the No-DC group (P<0.001). Furthermore, the incidences of bucking between the two groups were 1.0% and 9.8% (P =0.005). LCE satisfaction rates were respectively 78.4% and 76.5% in the DC and No-DC groups (P =0.363). Concerning symptoms after LCE, incidences of sore throat, pharyngeal discomfort or odor, bitter taste, and heartburn were also reduced in the DC group. (all P<0.05).

Conclusion: Adding DC as an auxiliary effect during LCE would reduce the risk of iodine solution reflux, as well as other adverse events after LCE. Implementing this measure could be beneficial in improving the safety of LCE in EEC screening.