Assessing the Feasibility of Using Methylene Blue in Identifying Ureters During Colorectal Surgery

October 1, 2026 updated by: Trevor Yeung, Chinese University of Hong Kong

This study will assess whether methylene blue fluorescence imaging can help surgeons identify the ureters during colorectal surgery. Methylene blue, given through a vein during the operation, is taken up and excreted by the kidneys, allowing the ureters to appear under a special fluorescence camera system.

The study will include adults undergoing open, laparoscopic, or robotic colorectal surgery at Prince of Wales Hospital. The surgeons will compare ureter visibility using standard white light with visibility using fluorescence imaging at different stages of the operation. The study will also assess the best dose of methylene blue, the additional time required, the ease of using the imaging system, and whether the imaging findings affect the surgical plan.

The study's hypothesis is that methylene blue fluorescence imaging will make it easier or faster to identify the ureters than white light alone. The technique will be considered feasible if it is helpful in at least 20% of operations-for example, by identifying a ureter earlier or identifying it when it cannot be seen under white light. The findings will help determine whether a larger future study should be conducted.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Aged ≥18 years
  • Scheduled to undergo open, laparoscopic or robotic colorectal surgery, including right colectomy, extended right colectomy, left colectomy, high anterior resection, low anterior resection, abdominoperineal resection, subtotal colectomy and total colectomy.

Exclusion Criteria:

  • Unable to understand the aims and objectives of this study and unable to give consent for participation
  • Known allergy to methylene blue
  • Pregnant
  • Taking selective serotonin reuptake inhibitors, serotonin and norepinephrine reuptake inhibitors, monoamine oxidase inhibitors, or tricyclic antidepressants (risk of serotonin syndrome)
  • Significant renal or hepatic impairment
  • Presence of renal or ureteric obstruction
  • History of G6PD deficiency (risk of hemolytic anemia)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Device Feasibility
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Methylene Blue Fluorescence Imaging Arm

Intravenous Methylene Blue with Fluorescence Imaging for Ureter Identification
Drug: Intravenous Methylene Blue

Intravenous Methylene Blue

Device: Methylene Blue Fluorescence Imaging System

Methylene Blue Fluorescence Imaging with Custom Optical Filter (Stryker 1688)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Proportion of cases in which fluorescence imaging with methylene blue is deemed helpful for identifying the index ureter
Time Frame: Intraoperative - at three predefined stages of the index operation (before dissection, before division of critical structures, and after specimen removal)
Intraoperative - at three predefined stages of the index operation (before dissection, before division of critical structures, and after specimen removal)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Chinese University of Hong Kong

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

October 1, 2028

Study Registration Dates

First Submitted

October 1, 2026

First Submitted That Met QC Criteria

October 1, 2026

First Posted (Actual)

October 6, 2026

Study Record Updates

Last Update Posted (Actual)

October 6, 2026

Last Update Submitted That Met QC Criteria

October 1, 2026

Last Verified

October 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Ureter MB Feasibility

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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