Effects of L-Menthol and Carbon Dioxide on the Adenoma Detection Rate during Colonoscopy: L-Menthol and Carbon Dioxide on Colonoscopy

• Published in: Digestion Vol. 101; no. 3; p. 323
• Main Authors: Inoue, Ken, Okuda, Takashi, Oka, Kohei, Sugino, Satoshi, Endo, Yuki, Ota, Takayuki, Minagawa, Yuki, Yasue, Chihiro, Tsuji, Toshifumi, Katayama, Takayuki, Nakamura, Hideki, Nagata, Akihiro, Komaki, Toshiyuki, Naito, Yuji, Itoh, Yoshito, Kagawa, Keizo
• Format: Journal Article
• Language: English
• Published: Switzerland 01-05-2020
• Subjects: Abdominal Pain - etiology; Abdominal Pain - prevention & control; Adenoma - diagnosis; Adenoma - epidemiology; Adult; Aged; Aged, 80 and over; Carbon Dioxide - administration & dosage; Colonoscopy - adverse effects; Colonoscopy - methods; Colorectal Neoplasms - diagnosis; Colorectal Neoplasms - epidemiology; Early Detection of Cancer - adverse effects; Early Detection of Cancer - methods; Female; Humans; Insufflation; Male; Menthol - administration & dosage; Middle Aged; Parasympatholytics - administration & dosage; Peristalsis - drug effects; Prospective Studies; Treatment Outcome; Young Adult; L-Menthol; Adenoma detection rate; Carbon dioxide
• ISSN: 1421-9867
• DOI: 10.1159/000498941

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.
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.
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.