Colorectal SurgeryPhase 4NCT07835932
Randomised Controlled Trial of Fluorescent Urography Using Intravenous Methylene Blue Compared to White Light Alone in Left-sided Colorectal Surgery
A Phase 4 study testing Intravenous Methylene blue and Fluorescence Imaging Device for Methylene Blue in people with Colorectal Surgery and Ureter, run by Chinese University of Hong Kong at 1 site in Hong Kong.
Trial summary
This study will see if a blue dye (methylene blue) given into a vein, together with a special camera light, helps surgeons find the left ureter (the tube from the kidney to the bladder) faster during left-sided bowel surgery. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Colorectal Surgery, Ureter
- What is being tested?
- Intravenous Methylene blue and Fluorescence Imaging Device for Methylene Blue
- Type of treatment
- Injection or infusion, Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 108 participants
- Where
- 1 siteHong Kong
- Study dates
- 1 Oct 2026to 1 Oct 2029
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Aged ≥18 years
- Scheduled to undergo open, laparoscopic or robotic left-sided colorectal surgery, including left colectomy, high anterior resection, low anterior resection, abdominoperineal resection, subtotal colectomy and total colectomy.
Who cannot join
- 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)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Hong Kong1 site
Prince of Wales Hospital, The Chinese University of Hong Kong
Hong Kong
Trevor Yeung, MA, MBBChir, DPhil, FRCS, +852 3505 1495, uretertrial@gmail.com
About this study
This study will see if a blue dye (methylene blue) given into a vein, together with a special camera light, helps surgeons find the left ureter (the tube from the kidney to the bladder) faster during left-sided bowel surgery. Adults having open, laparoscopic, or robotic left-sided colorectal surgery will be randomly assigned to either the blue dye with special light or standard white light alone. The main question is whether the blue dye method finds the ureter more quickly, which could make the operation safer.
Read the detailed description
This randomised controlled trial will test whether intravenous methylene blue, viewed with a special fluorescence camera, helps surgeons identify the left ureter (the tube that carries urine from the kidney to the bladder) more quickly during left-sided colorectal (bowel) surgery. Ureter injury is a rare but serious complication, and in some patients the ureter is hard to see under standard white light. Adults having open, laparoscopic, or robotic left-sided colorectal surgery at Prince of Wales Hospital (Hong Kong) will be screened; if the left ureter cannot be clearly seen before dissection, they will be randomly assigned to either fluorescence imaging with methylene blue or standard white-light vision alone.
The main outcome is the time from starting dissection to first seeing the left ureter. The study will also record how often the ureter is seen at set time points, operating times, surgeon-rated ease and confidence, any changes to the surgical plan, complications, and ureteric injuries. The goal is to find out whether the fluorescence method can make ureter identification faster and easier, potentially improving safety without needing invasive preoperative ureteric stents.
- Conditions
- Colorectal Surgery, Ureter
- Being tested
- Intravenous Methylene blue, Fluorescence Imaging Device for Methylene Blue
- Keywords
- Methylene Blue, Fluorescence imaging, Ureter identification, Colorectal surgery, Image-guided surgery
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intravenous Methylene blueDrug
Intravenous methylene blue 0.5-1.0 mg/kg administered intraoperatively for fluorescence ureter identification.
Fluorescence Imaging Device for Methylene BlueDevice
Modified Stryker 1688 Fluorescence Laparoscopic System with additional filter
| Study group | Role | What they receive |
|---|---|---|
| Fluorescence Imaging with Intravenous Methylene Blue | Experimental | Fluorescence Imaging with Intravenous Methylene Blue Receives: Drug: Intravenous Methylene blue; Device: Fluorescence Imaging Device for Methylene Blue |
| White Light Visualisation Alone | No intervention | White Light Visualisation Alone |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time to identification of the left ureter
Time (in minutes) from peritoneal incision to first visualisation of the left ureter during left-sided colorectal surgery.
Measured: Intraoperative, from peritoneal incision until the ureter is first seen
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Sep 2026
- Study start1 Oct 2026 (estimated)
- Primary completion1 Oct 2028 (estimated)
- Study completion1 Oct 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Colorectal SurgeryStudies of the same condition, open and under way.
- More trials run by Chinese University of Hong KongThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 108 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Chinese University of Hong Kong
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Trevor Yeung, Chinese University of Hong Kong
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07835932
- Sponsor's protocol ID
- Ureter MB RCT
- Status last verified
- Sep 2026
- First submitted
- 17 Sep 2026
- Last updated
- 23 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomised Controlled Trial of Fluorescent Urography Using Intravenous Methylene Blue Compared to White Light Alone in Left-sided Colorectal Surgery
- ClinicalTrials.gov ID
- NCT07835932
- Acronym / sponsor ID
- Ureter MB RCT
- Conditions
- Colorectal Surgery, Ureter
- Keywords
- Methylene Blue, Fluorescence imaging, Ureter identification, Colorectal surgery, Image-guided surgery
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 108 participants (estimated)
- Lead sponsor
- Chinese University of Hong KongUniversity, hospital or other
- Study start
- 1 Oct 2026 (estimated)
- Primary completion
- 1 Oct 2028 (estimated)
- Study completion
- 1 Oct 2029 (estimated)
- First posted
- 23 Sep 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study will see if a blue dye (methylene blue) given into a vein, together with a special camera light, helps surgeons find the left ureter (the tube from the kidney to the bladder) faster during left-sided bowel surgery. Adults having open, laparoscopic, or robotic left-sided colorectal surgery will be randomly assigned to either the blue dye with special light or standard white light alone. The main question is whether the blue dye method finds the ureter more quickly, which could make the operation safer.
Detailed description
This randomised controlled trial will test whether intravenous methylene blue, viewed with a special fluorescence camera, helps surgeons identify the left ureter (the tube that carries urine from the kidney to the bladder) more quickly during left-sided colorectal (bowel) surgery. Ureter injury is a rare but serious complication, and in some patients the ureter is hard to see under standard white light. Adults having open, laparoscopic, or robotic left-sided colorectal surgery at Prince of Wales Hospital (Hong Kong) will be screened; if the left ureter cannot be clearly seen before dissection, they will be randomly assigned to either fluorescence imaging with methylene blue or standard white-light vision alone.
The main outcome is the time from starting dissection to first seeing the left ureter. The study will also record how often the ureter is seen at set time points, operating times, surgeon-rated ease and confidence, any changes to the surgical plan, complications, and ureteric injuries. The goal is to find out whether the fluorescence method can make ureter identification faster and easier, potentially improving safety without needing invasive preoperative ureteric stents.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Fluorescence Imaging with Intravenous Methylene Blue | Experimental | Drug: Intravenous Methylene blue, Device: Fluorescence Imaging Device for Methylene BlueFluorescence Imaging with Intravenous Methylene Blue |
| White Light Visualisation Alone | No intervention | –White Light Visualisation Alone |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Aged ≥18 years
- Scheduled to undergo open, laparoscopic or robotic left-sided colorectal surgery, including left colectomy, high anterior resection, low anterior resection, abdominoperineal resection, subtotal colectomy and total colectomy.
Key exclusion criteria (7 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Intravenous Methylene blueIntravenous methylene blue 0.5-1.0 mg/kg administered intraoperatively for fluorescence ureter identification. | Drug | Fluorescence Imaging with Intravenous Methylene Blue |
| Fluorescence Imaging Device for Methylene BlueModified Stryker 1688 Fluorescence Laparoscopic System with additional filter | Device | Fluorescence Imaging with Intravenous Methylene Blue |
Primary outcome
Time to identification of the left ureter
Time frame: Intraoperative, from peritoneal incision until the ureter is first seen
Time (in minutes) from peritoneal incision to first visualisation of the left ureter during left-sided colorectal surgery.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Sep 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Intravenous Methylene blue and Fluorescence Imaging Device for Methylene Blue in people with Colorectal Surgery and Ureter, run by Chinese University of Hong Kong at 1 site in Hong Kong.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 23 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Hong Kong. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Trevor Yeung, MA, MBBChir, DPhil, FRCS (+852 3505 1495, uretertrial@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time to identification of the left ureter (time frame: Intraoperative, from peritoneal incision until the ureter is first seen). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 Sep 2026.