May-Thurner SyndromeNCT06180122
The Use and Reproducibility of Duplex Ultrasound to Provide Indices of Left Common Iliac Vein Diameter
A study testing Duplex ultrasound in people with May-Thurner Syndrome, run by Imperial College London at 1 site in United Kingdom.
Trial summary
The goal of this feasibility/pilot study is to investigate whether or not vascular ultrasound can be used to aid the diagnosis of May Thurner Syndrome, in adult patients presenting to the vascular department with unexplained left leg swelling. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- May-Thurner Syndrome
- What is being tested?
- Duplex ultrasound
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 5 Mar 2024to 21 May 2024
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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
- Participant has the capacity to consent
- Participant is required to have a vascular ultrasound scan in the vascular ultrasound department
- Participant is 18 years of age or older at the start of the study.
Who cannot join
- Previous iliac vein intervention or treatment for iliac vein disease
- Previous diagnosis of iliac vein thrombus
- Pregnancy
- Unable to provide appropriate informed consent
- The participant does not require a vascular ultrasound as part of their routine care
- Under 18 years of age at the start of the study
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Imperial College Healthcare NHS Trust
London, Greater London, W6 8RF
About this study
Official title: The Use and Reproducibility of Duplex Ultrasound to Provide Indices of Left Common Iliac Vein (CIV) Diameter, to Aid and Improve the Diagnosis of May Thurner Syndrome (MTS) in Patients Presenting With Unexplained Left Leg Swelling
The goal of this feasibility/pilot study is to investigate whether or not vascular ultrasound can be used to aid the diagnosis of May Thurner Syndrome, in adult patients presenting to the vascular department with unexplained left leg swelling. The main research objective it aims to answer are:
- The diameter variation of the left common iliac vein based on posture, using duplex ultrasound.
- To determine inter- and intra-observer variation of the diameter measurement of the left common iliac vein using duplex ultrasound.
Read more
Participants will have an ultrasound scan performed on their abdomen by three different clinical vascular scientists, and will have each scan performed whilst lying supine on an examination couch and again when the couch is tilted to 45 degrees.
Researchers will compare the results of symptomatic patients to asymptomatic patients, to see if there is a difference in the diameter of the left common iliac vein between these two groups.
- Conditions
- May-Thurner Syndrome
- Being tested
- Duplex ultrasound
- Medical subject headings
- May-Thurner Syndrome
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Duplex ultrasoundDiagnostic test
Vascular ultrasound scan of the left common iliac vein
| Study group | Role | What they receive |
|---|---|---|
| Symptomatic Group | Other | Participants who are suffer from unexplained left leg swelling. Receives: Diagnostic Test: Duplex ultrasound |
| Asymptomatic Group | Other | Participants who do not suffer from unexplained left leg swelling Receives: Diagnostic Test: Duplex ultrasound |
What is being measured
The primary outcome is the main question the study is designed to answer.
Left Common Iliac Vein Diameter
The diameter measurement (in mm) of the left common iliac vein in adults referred to the vascular ultrasound department.
Measured: Baseline
Secondary outcomes (1)
Inter-and Intra-operator Variation of the Diameter Measurement of the Left Common Iliac Vein
The inter- and intra-operator variation of the diameter measurement of the left common iliac vein using duplex ultrasound, in adults referred to the vascular ultrasound department. Three different scientists took three measurements each of the common iliac vein. The results from the three scientists were compared to determine inter-operator variation, and the results from one scientist each were compared to determine intra-operator variation.
Measured: Baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Dec 2023
- Study start5 Mar 2024
- Primary completion21 May 2024
- Study completion21 May 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for May-Thurner SyndromeStudies of the same condition, open and under way.
- More trials run by Imperial College LondonThe 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 N/A
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Imperial College London
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06180122
- Sponsor's protocol ID
- 23CX8043
- Status last verified
- Aug 2025
- First submitted
- 12 Dec 2023
- Last updated
- 3 Sep 2025
- Results posted
- Yes, on ClinicalTrials.gov
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 3 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Use and Reproducibility of Duplex Ultrasound to Provide Indices of Left Common Iliac Vein (CIV) Diameter, to Aid and Improve the Diagnosis of May Thurner Syndrome (MTS) in Patients Presenting With Unexplained Left Leg Swelling
- ClinicalTrials.gov ID
- NCT06180122
- Acronym / sponsor ID
- 23CX8043
- Conditions
- May-Thurner Syndrome
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Imperial College LondonUniversity, hospital or other
- Study start
- 5 Mar 2024 (actual)
- Primary completion
- 21 May 2024 (actual)
- Study completion
- 21 May 2024 (actual)
- First posted
- 22 Dec 2023 (actual)
- Results
- Posted 3 Sep 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this feasibility/pilot study is to investigate whether or not vascular ultrasound can be used to aid the diagnosis of May Thurner Syndrome, in adult patients presenting to the vascular department with unexplained left leg swelling. The main research objective it aims to answer are:
- The diameter variation of the left common iliac vein based on posture, using duplex ultrasound.
- To determine inter- and intra-observer variation of the diameter measurement of the left common iliac vein using duplex ultrasound.
Participants will have an ultrasound scan performed on their abdomen by three different clinical vascular scientists, and will have each scan performed whilst lying supine on an examination couch and again when the couch is tilted to 45 degrees.
Researchers will compare the results of symptomatic patients to asymptomatic patients, to see if there is a difference in the diameter of the left common iliac vein between these two groups.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Symptomatic Group | Other | Diagnostic Test: Duplex ultrasoundParticipants who are suffer from unexplained left leg swelling. |
| Asymptomatic Group | Other | Diagnostic Test: Duplex ultrasoundParticipants who do not suffer from unexplained left leg swelling |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Participant has the capacity to consent
- Participant is required to have a vascular ultrasound scan in the vascular ultrasound department
- Participant is 18 years of age or older at the start of the study.
Key exclusion criteria (6 listed)
- Previous iliac vein intervention or treatment for iliac vein disease
- Previous diagnosis of iliac vein thrombus
- Pregnancy
- Unable to provide appropriate informed consent
- The participant does not require a vascular ultrasound as part of their routine care
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 |
|---|---|---|
| Duplex ultrasoundVascular ultrasound scan of the left common iliac vein | Diagnostic test | Asymptomatic Group, Symptomatic Group |
Primary outcome
Left Common Iliac Vein Diameter
Time frame: Baseline
The diameter measurement (in mm) of the left common iliac vein in adults referred to the vascular ultrasound department.
1 secondary outcome
Inter-and Intra-operator Variation of the Diameter Measurement of the Left Common Iliac Vein
Time frame: Baseline
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Sep 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Undecided
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RecruitingObservational study
Vascular Lab Resource (VLR) Biorepository
Cardiovascular Diseases, Metabolic Disease
Recruiting
Anticoagulant Plus Antiplatelet Therapy Following Iliac Vein Stenting
Deep Vein Thrombosis, Iliac Vein Thrombosis
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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Duplex ultrasound in people with May-Thurner Syndrome, run by Imperial College London at 1 site in United Kingdom.
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 3 inclusion and 6 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: finished, as of the sponsor's last update on 3 Sep 2025. 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 United Kingdom. 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.
Are results available for this study?
Yes. Results are posted in the registry (first posted 3 Sep 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Left Common Iliac Vein Diameter (time frame: Baseline). 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 3 Sep 2025; AzTrials last refreshed its copy on 8 Nov 2026.