title: Water exchange for screening colonoscopy increases adenoma detection rate: a multicenter, double-blinded, randomized controlled trial.
abstract: Background and study aimsSingle-center studies, which were retrospective and/or involved unblinded colonoscopists, have suggested that water exchange, but not water immersion, compared with air insufflation significantly increases the adenoma detection rate (ADR), particularly in the proximal and right colon. Head-to-head comparison of the three techniques with ADR as primary outcome and blinded colonoscopists has not been reported to date. In a randomized controlled trial with blinded colonoscopists, we aimed to evaluate the impact of the three insertion techniques on ADR.Patients and methodsA total of 1224 patients aged 50 - 70 years (672 males) and undergoing screening colonoscopy were randomized 1:1:1 to water exchange, water immersion, or air insufflation. Split-dose bowel preparation was adopted to optimize colon cleansing. After the cecum had been reached, a second colonoscopist who was blinded to the insertion technique performed the withdrawal. The primary outcome was overall ADR according to the three insertion techniques (water exchange, water immersion, and air insufflation). Secondary outcomes were other pertinent overall and right colon procedure-related measures.ResultsBaseline characteristics of the three groups were comparable. Compared with air insufflation, water exchange achieved a significantly higher overall ADR (49.3 %, 95 % confidence interval [CI] 44.3 % - 54.2 % vs. 40.4 % 95 %CI 35.6 % - 45.3 %;P= 0.03); water exchange showed comparable overall ADR vs. water immersion (43.4 %, 95 %CI 38.5 % - 48.3 %;P= 0.28). In the right colon, water exchange achieved a higher ADR than air insufflation (24.0 %, 95 %CI 20.0 % - 28.5 % vs. 16.9 %, 95 %CI 13.4 % - 20.9 %;P= 0.04) and a higher advanced ADR (6.1 %, 95 %CI 4.0 % - 9.0 % vs. 2.5 %, 95 %CI 1.2 % - 4.6 %;P= 0.03). Compared with air insufflation, the mean number of adenomas per procedure was significantly higher with water exchange (P= 0.04). Water exchange achieved the highest cleanliness scores (overall and in the right colon). These variables were comparable between water immersion and air insufflation.ConclusionsThe design with blinded observers strengthens the validity of the observation that water exchange, but not water immersion, can achieve significantly higher adenoma detection than air insufflation. Based on this evidence, the use of water exchange should be encouraged.Trial registered at ClinicalTrials.gov (NCT02041507).
authors.affiliation: Digestive Endoscopy Unit, St. Barbara Hospital, Iglesias, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Cadoni
authors.affiliation: Digestive Diseases Center, Vitkovice Hospital, Ostrava, Czech Republic.
authors.forename: Přemysl
authors.initials: P
authors.lastname: Falt
authors.affiliation: Division of Digestive Endoscopy and Gastroenterology, Valduce Hospital, Como, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Rondonotti
authors.affiliation: Division of Digestive Endoscopy and Gastroenterology, Valduce Hospital, Como, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Radaelli
authors.affiliation: Digestive Diseases Center, Vitkovice Hospital, Ostrava, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Fojtik
authors.affiliation: Digestive Endoscopy Unit, St. Barbara Hospital, Iglesias, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Gallittu
authors.affiliation: Digestive Endoscopy Unit, St. Barbara Hospital, Iglesias, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Liggi
authors.affiliation: Division of Digestive Endoscopy and Gastroenterology, Valduce Hospital, Como, Italy.
authors.forename: Arnaldo
authors.initials: A
authors.lastname: Amato
authors.affiliation: Division of Digestive Endoscopy and Gastroenterology, Valduce Hospital, Como, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Paggi
authors.affiliation: Digestive Diseases Center, Vitkovice Hospital, Ostrava, Czech Republic.
authors.forename: Vit
authors.initials: V
authors.lastname: Smajstrla
authors.affiliation: Digestive Diseases Center, Vitkovice Hospital, Ostrava, Czech Republic.
authors.forename: Ondřej
authors.initials: O
authors.lastname: Urban
authors.affiliation: Department of Surgical Sciences, University of Cagliari, Cagliari, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Erriu
authors.affiliation: Department of Medical Research, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan.
authors.forename: Malcolm
authors.initials: M
authors.lastname: Koo
authors.affiliation: Sepulveda Ambulatory Care Center, Veterans Affairs Greater Los Angeles Healthcare System, North Hills, California, United States.
authors.forename: Felix W
authors.initials: FW
authors.lastname: Leung
mesh_terms: D000236:Adenoma / Q000000981:diagnostic imaging*; D000368:Aged; D000388:Air; D002400:Cathartics / Q000008:administration & dosage; D044682:Colon, Ascending; D044684:Colon, Transverse; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging*; D003113:Colonoscopy / Q000379:methods*; D004311:Double-Blind Method; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D006801:Humans; D007327:Insufflation; D008297:Male; D008875:Middle Aged; D007507:Therapeutic Irrigation / Q000379:methods; D014867:Water
chemical_list: D002400:Cathartics; D014867:Water