Impact of water exchange colonoscopy on serum sodium and potassium levels: an observational study

Effectiveness of Water-Assisted Colonoscopy without Sedation in Patients with Ulcerative Colitis

BACKGROUND

Studies have found that water-assisted colonoscopy (WAC) including water immersion colonoscopy (WIC) and water exchange colonoscopy (WEC) is superior to air insufflation colonoscopy (AIC) in terms of the cecal intubation rate. However, the application of WAC in ulcerative colitis (UC) has rarely been reported. This study aimed to explore the effectiveness of WAC without sedation in patients with UC.

METHODS

One hundred and seventy-two UC patients were randomly divided into the AIC group (n = 56), WIC group (n = 58), and WEC group (n = 58). The cecal intubation rate, abdominal pain score, operator difficulty, bowel cleanliness, insertion, and total time were compared.

RESULTS

The cecal intubation rate was higher in the WIC (91.4% vs. 75.0%; mean difference = 16.4%; 95% CI: 3.0-29.8%) and WEC (93.1% vs. 75.0%; mean difference = 18.1%; 95% CI: 5.0-31.2%) compared to the AIC group, while there was no difference between the WIC and WEC groups. The abdominal pain score and operator difficulty were lower in the WIC and WEC groups than in the AIC group, while there was no difference between the WIC and WEC groups. The bowel cleanliness during withdrawal was higher in the WIC and WEC groups than in the AIC group, while the WEC was superior to WIC. Compared with the AIC and WIC groups, the insertion time and total time were longer in the WEC group, and there was no difference in the AIC group and WIC group.

CONCLUSION

In comparison with AIC, WAC can increase the cecal intubation rate, reduce abdominal pain scores and improve bowel cleanliness in patients with UC.

Water exchange-assisted versus carbon dioxide-insufflated single-balloon enteroscopy: a randomized controlled trial

BACKGROUND

Single-balloon enteroscopy (SBE) is a valuable but difficult modality for the diagnosis and treatment of small-bowel disease. The water exchange method has the advantage of facilitating intubation during colonoscopy. Here, we evaluated the effects of water exchange on procedure-related variables related to SBE.

METHODS

This randomized controlled trial was conducted in a tertiary-care referral center in China. Patients due for attempted total enteroscopy were randomly allocated to undergo water exchange-assisted (water exchange group) or carbon dioxide-insufflated enteroscopy (CO₂ group). All patients were planned to undergo both anterograde and retrograde procedures. The primary outcome was the total enteroscopy rate. Secondary outcomes included the maximal insertion depth, positive findings, procedural time, and adverse events.

RESULTS

In total, 110 patients were enrolled, with 55 in each group. Baseline characteristics between the two groups were comparable. Total enteroscopy was achieved in 58.2 % (32/55) of the water exchange group and 36.4 % (20/55) of the control group (P = 0.02). The mean (standard deviation) estimated intubation depth was 521.2 (101.4) cm in the water exchange group and 481.6 (95.2) cm in the CO₂ group (P = 0.04). The insertion time was prolonged in the water exchange group compared with the CO₂ group (178.9 [45.1] minutes vs. 154.2 [27.6] minutes; P < 0.001). Endoscopic findings and adverse events were comparable between the two groups.

CONCLUSIONS

The water exchange method improved the total enteroscopy rate and increased the intubation depth during SBE. The use of water exchange did not increase the complications of enteroscopy.

Diagnostic application of water exchange colonoscopy: A meta-analysis of randomized controlled trials

Background

Few well-designed studies have investigated water exchange colonoscopy (WE). We performed a meta-analysis to comprehensively evaluate the clinical utility of WE based on high-quality randomized controlled trials (RCTs) and to compare the impacts of WE, water immersion colonoscopy (WI), and gas-insufflation colonoscopy.

Methods

We searched the Cochrane Library, MEDLINE, Embase, PubMed, Elsevier, CNKI, VIP, and Wan Fang Data for RCTs on WE. We analyzed the results using fixed- or random-effect models according to the presence of heterogeneity. Publication bias was assessed by funnel plots.

Results

Thirteen studies were eligible for this meta-analysis. The colonoscopic techniques included WE as the study group, and WI and air- or CO₂-insufflation colonoscopy as control groups. WE was significantly superior to the control procedures in terms of adenoma detection rate, proportion of painless unsedated colonoscopy procedures, and cecal intubation rate according to odds ratios. WE was also significantly better in terms of maximal pain score and patient satisfaction score according to mean difference.

Conclusions

WE can remarkably improve the adenoma detection rate, proportion of painless unsedated colonoscopy procedures, patient satisfaction, and cecal intubation rate, as well as reducing the maximal pain score in patients undergoing colonoscopy.

Water-aided colonoscopy

The successful intubation of the cecum during screening or surveillance colonoscopy is vital to ensure complete mucosal inspection of the colon on withdrawal. Even when performed by an experienced endoscopist, colonoscope insertion can sometimes be challenging. Water-aided colonoscopy can be used to assist the endoscopist in navigating colons with anatomies that may be challenging owing to severe angulation or redundancy. Water-assisted colonoscopy involves the infusion of water without air and subsequent suctioning during insertion (exchange) or withdrawal (immersion or infusion). This review discusses the technique, effectiveness, safety of water-assisted colonoscopy as well as the application in sedationless endscopy.

Water exchange vs. water immersion during colonoscope insertion

Water exchange (water infusion with water removal primarily during insertion) and water immersion (water infusion with water removal during withdrawal) reduce patient discomfort during colonoscope insertion compared with air insufflation, and represent a major achievement in colonoscopy. Hsieh et al. found that water exchange, relative to water immersion, resulted in more painless insertions to the cecum and improved adenoma detection in the right colon. However, water exchange is also associated with better bowel cleansing and longer insertion and procedure times. These factors are not specific to water exchange, but could account for all or part of the better results with water exchange. Additional controlled investigation is needed to define the benefits of water exchange compared with water immersion.