Feasibility of Water Colonoscopy in a Canadian Community Population

Abstract

Purpose: Water-aided methods, either by immersion or exchange, minimize pain during colonoscopy, thereby reducing or eliminating sedation requirements. Water exchange, in particular, also enhances adenoma detection rates (ADR) when compared to air insufflation. Previous descriptions of the technique in North America involved predominantly male VA populations. In the context of a performance improvement program, to establish the feasibility of using water-aided methods in one busy GI community practice in Canada. Methods: At the Kelowna General Hospital, over a 13 month period patients presenting for colonoscopy, for all indications, were offered a colonoscopy using the water-aided methods and an option to attempt the procedure without sedation. The method of water immersion was performed in the first 1-2 months and replaced exclusively with water exchange thereafter. Communication with a knowledgeable trainer via email facilitated learning and conversion to the water exchange method. Colonoscopy was performed by two endoscopists. Standard colonoscopes were used. Water was infused with a paddle pump. Clean water was infused to facilitate insertion while suctioning cloudy water. Once cecal intubation was achieved air insufflation allowed examination and polyp removal on withdrawal. Procedural outcomes were recorded. Results: 200 (106M/94F) water-aided colonoscopies were completed, 81 for screening, 64 for surveillance and 55 were diagnostic. The intent-to-treat cecal intubation rate was 93%. 97 patients (62M/35F) of 102 (64M/38F), 95% who consented to the procedure without sedation successfully completed it without on demand sedation. Average insertion time was 15 min with an average withdrawal time of 6 min (excluding polypectomy) for an overall average procedure time of 21 min for all indications. The overall ADR for patients with a screening/surveillance indication was 30% (43/145), 36% (31/87) in males and 21% (12/58) in females with an overall proximal ADR of 21% (31/145), 25% (22/87) in males and 16% (9/58) in females and an overall sessile serrated polyp detection rate of 4% (5/145). Two advanced adenomas and one cancer were identified in 2% of patients (3/145). Conclusion: Water-aided methods are feasible and can be integrated into a busy community practice. Rates of cecal intubation are similar to published results. ADR are higher than recommended quality standards (male 25%, female 15%). These results are instrumental in generating funding support provided by the Canadian Association of Gastroenterology and the Canadian Digestive Health Foundation to conduct a prospective RCT to evaluate the approach of extended, unsedated flexible sigmoidoscopy using water exchange as a universal screening examination.