Evaluating the Clinical Value of Transparent Cap-Assisted Second Examination of the Sigmoid Colon for Improving Colorectal Adenoma Detection Rates

Evaluating the Clinical Value of Transparent Cap-Assisted Second Examination of the Sigmoid Colon for Improving Colorectal Adenoma Detection Rates：A Single-center, Randomized Controlled Study

A prospective, single-center, single-blind, randomized controlled study to evaluate the clinical value of transparent cap-assisted second examination of the sigmoid colon for improving colorectal adenoma detection rates

Study Overview

• Status: Not yet recruiting
• Conditions: Colorectal Adenoma
• Intervention / Treatment: Device: standard second examination of the sigmoid colon; Device: transparent cap-assisted second examination of the sigmoid colon

Detailed Description

Colorectal cancer (CRC) is the third most common malignancy worldwide and the second leading cause of cancer-related mortality. In recent years, with the increasing Westernization of diet and lifestyle, the incidence and prevalence of CRC in China have risen rapidly, making CRC one of the most common gastrointestinal malignancies in the country. Its incidence and mortality now rank second and fifth, respectively, among all cancers. The disease burden of CRC in China has become substantial, and reducing its incidence and mortality is an urgent public health priority. Colonoscopy is the gold standard for CRC screening, and timely endoscopic management of precancerous lesions plays a critical role in reducing both CRC incidence and mortality.

Interval CRC refers to cancers diagnosed before the next recommended examination after a negative screening or surveillance colonoscopy. Adenoma detection rate (ADR) is an independent predictor of interval CRC risk; long-term follow-up data suggest that every 1% increase in ADR corresponds to a 5% reduction in the risk of interval CRC and a 3% reduction in mortality. However, emerging evidence indicates that interval CRC can still occur even among endoscopists with high ADRs, suggesting that some precancerous lesions may still be missed.

The main contributors to missed colorectal adenomas include: (1) operator-related factors such as fatigue, reduced attention, or limited lesion recognition; (2) image-related factors such as low-resolution visualization; and (3) inadequate mucosal exposure due to residual folds. In recent years, several studies have explored the use of "repeat intubation" to reduce missed adenomas. Multiple randomized controlled trials (RCTs) and systematic reviews have shown that a second examination can increase ADR, but most studies have focused on the right colon and often relied on chromoendoscopy or other image-enhancement modalities to improve lesion visibility. Evidence regarding second intubation specifically for the sigmoid colon remains limited, and even fewer studies have evaluated interventions based on transparent cap-assisted colonoscopy. Given that the sigmoid colon is a common site for missed polyps and adenomas, optimizing visualization in this segment may have a significant impact on overall ADR and CRC prevention.

In summary, there is still a lack of clinical evidence on whether transparent cap-assisted second intubation of the sigmoid colon can improve colorectal adenoma detection. A randomized controlled trial in the Chinese population is therefore needed to clarify its clinical value, with the potential to increase lesion detection and improve the overall quality of colonoscopy.

• Study Type: Interventional
• Enrollment (Estimated): 614
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Danian Ji, M.D.; Phone Number: +86-18019094606; Email: arctg4@163.com
• Study Contact Backup: Name: Zhiyu Dong, M.D.; Phone Number: +86-18817870866; Email: 18817870866@163.com

Study Locations

• China
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China, 200040
      • Huadong Hospital, Fudan University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• aged 45-75 years

Exclusion Criteria:

• Patients scheduled for therapeutic colonoscopy as postoperative surveillance after colorectal surgery, post-polypectomy follow-up, or treatment of histologically confirmed polyps
• Patients with highly suspected or pathologically confirmed colorectal cancer
• Patients presenting with alarm symptoms or signs (hematochezia, melena, unexplained anemia or weight loss, palpable abdominal mass, or a positive digital rectal examination)
• Pregnant or breastfeeding women
• Patients with gastrointestinal obstruction
• Patients with inflammatory bowel disease, familial adenomatous polyposis, or serrated polyposis syndrome
• Patients who have taken anticoagulants (e.g., aspirin, warfarin) within 7 days before colonoscopy or who have coagulation disorders
• Patients currently enrolled in another clinical study or who participated in any clinical trial within the past 60 days
• Insertion failure for any reason (e.g., scope cannot pass an obstruction, patient cannot tolerate the procedure) or colonoscopy not reaching the cecum
• A Boston Bowel Preparation Scale (BBPS) score < 6 at scope insertion (inadequate preparation requiring repeat bowel cleansing)
• Use of non-guideline-recommended bowel preparation agents
• Patients undergoing emergency colonoscopy
• Inadequate withdrawal time (defined as a withdrawal time <6 minutes during the first examination or <2 minutes during the second examination)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Standard second examination of the sigmoid colon	Device: standard second examination of the sigmoid colon; standard second examination of the sigmoid colon
Experimental: transparent cap-assisted second examination of the sigmoid colon	Device: transparent cap-assisted second examination of the sigmoid colon; transparent cap-assisted second examination of the sigmoid colon

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Adenoma detection rate in the rectum and sigmoid colon	2 weeks after the procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinically Significant Immediate Post-polypectomy Bleeding（CSIPB）rate	CSIPB was defined as any bleeding not responding to water jet irrigation or STSC and therefore requiring either coagu lation forceps or mechanical clips to achieve hemostasis	immediately after the procedure
Clinically Significant Delayed Post-polypectomy Bleeding（CSDPB）rate	CSPEB was defined as any bleeding after completion of the procedure requiring emergency room presentation, hospital isation or re-intervention (endoscopy, angiography, surgery).	2 weeks after the procedure
Increased adenoma detection rate in the rectum and sigmoid colon achieved by second examination		2 weeks after the procedure
Adenoma miss rate in the rectum and sigmoid colon		2 weeks after the procedure
Per-colonoscopy adenoma miss rate in the rectum and sigmoid colon		2 weeks after the procedure
Sessile serrated lesion detection rate in rectum and sigmoid colon		2 weeks after the procedure
Advanced adenoma detection rate in rectum and sigmoid colon		2 weeks after the procedure
Polyp detection rate in rectum and sigmoid colon		2 weeks after the procedure
Sessile serrated lesion detection rate		2 weeks after the procedure
Advanced adenoma detection rate		2 weeks after the procedure
Polyp detection rate		2 weeks after the procedure
Perforation rate		immediately after the procedure

Collaborators and Investigators

• Sponsor: Fudan University
• Investigators: Study Director: Danian Ji, Huadong Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): December 15, 2025
• Primary Completion (Estimated): December 15, 2027
• Study Completion (Estimated): December 15, 2027

Study Registration Dates

• First Submitted: November 22, 2025
• First Submitted That Met QC Criteria: November 22, 2025
• First Posted (Estimated): December 3, 2025

Study Record Updates

• Last Update Posted (Estimated): December 3, 2025
• Last Update Submitted That Met QC Criteria: November 22, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: adenoma detection rate; sigmoid colon; transparent cap; second examination
• Other Study ID Numbers: 2025K351

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All collected IPD
• IPD Sharing Time Frame: 1 year after completion of this study
• IPD Sharing Access Criteria: All researchers can require the original data from principal investigator of this study (Email address: arctg4@163.com)
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No