Cap-assisted water immersion for minimal sedation colonoscopy: prospective, randomized, single-center trial.

Background And Aim: Water immersion insertion is able to reduce discomfort and need for sedation during colonoscopy. A cap attached to the colonoscope tip may improve insertion during air insufflation colonoscopy. According to several reports, both techniques alone may result in higher detection of neoplastic lesions. Our study was designed to evaluate the efficacy of cap-assisted water immersion compared to water immersion colonoscopy in minimally sedated patients.

Methods: A total of 208 consecutive outpatients were randomized to either cap-assisted water immersion (Cap Water) or water immersion colonoscopy (Water). The primary endpoint was cecal intubation time.

Results: Cecal intubation time was 6.9 ± 2.9 min in Cap Water and 7.4 ± 4.2 min in the Water arm (P = 0.73). Success rate of minimal sedation colonoscopy was equal in both groups (92.9%, P = 1.00). From the endoscopist's point of view, there were non-significant trends towards lower discomfort (P = 0.06), less need for abdominal compression (P = 0.06) and lower difficulty score (P = 0.05) during Cap Water colonoscopy. Adenoma detection rate was similar in both arms (44% in Cap Water vs 45% in the Water group, P = 0.88). There were no complications recorded in the present study.

Conclusions: In comparison with water immersion without cap, cap-assisted water immersion colonoscopy was not able to shorten the cecal intubation time. However, it has the possibility of reducing patient discomfort and difficulty of colonoscope insertion. Potential impact on improved detection of neoplastic lesions has to be evaluated by further studies.