The Use and Reproducibility of Duplex Ultrasound to Provide Indices of Left Common Iliac Vein Diameter

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.

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 Overview

• Status: Completed
• Conditions: May-Thurner Syndrome
• Intervention / Treatment: Diagnostic test: Duplex ultrasound

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Greater London
    • London, Greater London, United Kingdom, W6 8RF
      • Imperial College Healthcare NHS Trust

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• 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.

Exclusion Criteria:

• 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Symptomatic Group; Participants who are suffer from unexplained left leg swelling.	Diagnostic test: Duplex ultrasound; Vascular ultrasound scan of the left common iliac vein
Other: Asymptomatic Group; Participants who do not suffer from unexplained left leg swelling	Diagnostic test: Duplex ultrasound; Vascular ultrasound scan of the left common iliac vein

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Left Common Iliac Vein Diameter	The diameter measurement (in mm) of the left common iliac vein in adults referred to the vascular ultrasound department.	Baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Baseline

Collaborators and Investigators

• Sponsor: Imperial College London

Study record dates

Study Major Dates

• Study Start (Actual): March 5, 2024
• Primary Completion (Actual): May 21, 2024
• Study Completion (Actual): May 21, 2024

Study Registration Dates

• First Submitted: December 12, 2023
• First Submitted That Met QC Criteria: December 21, 2023
• First Posted (Actual): December 22, 2023

Study Record Updates

• Last Update Posted (Estimated): September 3, 2025
• Last Update Submitted That Met QC Criteria: August 13, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Congenital Abnormalities; Cardiovascular Abnormalities; Peripheral Vascular Diseases; Vascular Malformations; Congenital, Hereditary, and Neonatal Diseases and Abnormalities; May-Thurner Syndrome; Diagnostic Techniques and Procedures; Diagnosis; Diagnostic Imaging; Ultrasonography; Ultrasonography, Doppler; Ultrasonography, Doppler, Duplex
• Other Study ID Numbers: 23CX8043

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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