---
title: Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy
nct_id: NCT02880748
overall_status: UNKNOWN
phase: NA
sponsor: Air Force Military Medical University, China
study_type: INTERVENTIONAL
primary_condition: Adenoma
countries: China
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT02880748.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT02880748"
ct_last_update_post_date: 2016-08-26
last_seen_at: "2026-05-12T06:44:34.085Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy

**Official Title:** Effect of Water Exchange Method on Adenoma Miss Rates in Patients Undergoing Selective Polypectomy: a Single-centered, Randomized Controlled Study

**NCT ID:** [NCT02880748](https://clinicaltrials.gov/study/NCT02880748)

## Key Facts

- **Status:** UNKNOWN
- **Phase:** NA
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 450
- **Lead Sponsor:** Air Force Military Medical University, China
- **Conditions:** Adenoma
- **Start Date:** 2016-08
- **Completion Date:** 2017-08
- **CT.gov Last Update:** 2016-08-26

## Brief Summary

Patients with colorectal adenomas are suggested to receive polypectomy. A substantial number of adenomas may be missed in patients with polyps found by previous colonoscopy. And water exchange (WE) method may increase the detection of missed adenoma compared with traditional air insufflation (AI) colonoscopy. The investigators aim to investigate whether water exchange colonoscopy method, compared with air insufflation method, can improve the detection of missed adenomas in patients undergoing selective polypectomy.

## Detailed Description

For WE method, the air pump was turned off for the full duration of insertion to avoid inadvertent air insufflations and colon elongation. Residual air in the lumen was suctioned to minimize angulations at flexures. Water at 37°C was infused with a pump (Olympus) through the biopsy channel to confirm correct tip orientation for scope advancement. The infused water was removed predominantly by suction when the colonoscope was smoothly advanced during the insertion phase, and turbid luminal water due to residual feces was exchanged by clean water until the lumen was clearly visualized. Occasionally, if it was difficult to determine whether the colonoscope tip was in the cecum, air was allowed to be insufflated for observation. If the position of the scope tip was confirmed to be not in the cecum, insufflated air would be removed by suction and the WE method would be continuously used until successful intubation.

For the AI method, water was not used, and air was insufflated during insertion.

Air was insufflated to distend the lumen for inspection and biopsy or polypectomy during withdrawal for both methods. Polyps will be removed by forceps biopsy (polyps size \<3mm), cold snare technique (3-6mm) or endoscopic mucosal resection (size≥6mm).

## Eligibility

- **Minimum age:** 18 Years
- **Maximum age:** 80 Years
- **Sex:** ALL
- **Healthy Volunteers:** No

```
Inclusion Criteria:

* Age 18-80 patients undergoing selective polypectomy

Exclusion Criteria:

* Polyps found more than 6 months
* Patients with polyposis syndrome or hereditary nonpolyposis colorectal cancer
* Patients with history of inflammatory bowel disease
* Patients with planning to undergo Endoscopic Submucosal Dissection(ESD)
* Patients not undergoing standard bowel preparation
* Patients with solid feces in the last stool after bowel preparation
* Patients considered to be high risk for bleeding during Endoscopic mucosal resection (EMR), e.g. using antiplatelet drugs (clopidogrel) within 5 days before the current colonoscopy
* Hemodynamically unstable
* Pregnant women
* Unable to provide informed consent
```

## Arms

- **Water exchange (WE) method** (EXPERIMENTAL) — Water exchange (WE) method was used for insertion to the cecum.
- **Air insufflation (AI) method** (ACTIVE_COMPARATOR) — Air insufflation (AI) method was used for insertion to the cecum.

## Interventions

- **Water exchange (WE) method** (OTHER) — Water exchange (WE) method was used for insertion to the cecum. And air was insufflated to distend the lumen for inspection and biopsy or polypectomy during withdrawal procedure.
- **Air insufflation (AI) method.** (OTHER) — Air insufflation (AI) method was used for insertion to the cecum. And air was insufflated to distend the lumen for inspection and biopsy or polypectomy during withdrawal procedure.

## Primary Outcomes

- **Adenoma miss rate** _(time frame: 12 months)_ — Adenoma miss rate was calculated as the number of patients with one and more additional adenomas during polypectomy procedure divided by the total number of patients in each group.

## Secondary Outcomes

- **adenoma-level miss rate** _(time frame: 12 months)_
- **Advanced adenoma miss rate/Miss advanced adenoma per colonoscopy** _(time frame: 12 months)_
- **Adenoma per positive patient (APP)** _(time frame: 12 months)_
- **Quality of Bowel Preparation** _(time frame: 12 months)_
- **Complication rate** _(time frame: 12 months)_
- **Pain Scores on the Visual Analog Scale compared with previous colonoscopy** _(time frame: 12 months)_

## Locations (1)

- Endoscopic center, Xijing Hospital of Digestive Diseases, Xi'an, Shaanxi, China — _RECRUITING_

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.endoscopic center, xijing hospital of digestive diseases|xi'an|shaanxi|china` — added _(2026-05-12)_

---

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*Source data (authoritative): https://clinicaltrials.gov/study/NCT02880748*  
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