Supplementary Material for: Effects of L-Menthol and Carbon Dioxide on the Adenoma Detection Rate during Colonoscopy: L-Menthol and Carbon Dioxide on Colonoscopy
datasetposted on 07.03.2019, 08:37 by Inoue K., Okuda T., Oka K., Sugino S., Endo Y., Ota T., Minagawa Y., Yasue C., Tsuji T., Katayama T., Nakamura H., Nagata A., Komaki T., Naito Y., Itoh Y., Kagawa K.
Background and Aims: We examined the efficacy of the combined use of L-menthol spraying (L-mentholS) as an antispasmodic agent and carbon dioxide insufflation (CO2I) on the adenoma detection rate (ADR) in a prospective, single-center trial with a 2 × 2 factorial design. Methods: We randomly assigned 611 patients scheduled to undergo colonoscopy to 4 groups: (1) the L-mentholS + CO2I (n = 153), (2) L-mentholS + air insufflation (AI; n = 156), (3) CO2I (n = 153), and (4) AI (n = 149) groups. We used 20 mL of 0.8%-L-menthol solution for the L-mentholS. The primary outcome was the difference in the ADR, and the secondary outcomes were the differences in colonic peristalsis and abdominal pain. Results: The ADRs were not different among the groups: 1/2/3/4; 39.9%/43.6%/41.2%/51.0%. CO2I was associated with a significant decrease in the ADR (OR 0.57; 95% CI 0.35– 0.93) with a multiple logistic regression. The interaction between L-mentholS and CO2I was associated with a suppression of the decrease in the ADR. Both L-mentholS and CO2I were associated with a significant decrease in abdominal pain, and L-mentholS was associated with a significant improvement of peristalsis. Conclusions: The fact that CO2I was associated with significant decreases in the ADR was a problem. The combined use of L-mentholS and CO2I could help to suppress the decrease in the ADR.