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Completed

NCT Number: NCT04934501

Blood Flow Quantification Near Stented SFA Lesions Using Ultrasound Velocimetry

Peripheral arterial disease (PAD) in the lower extremity is the third leading cause of atherosclerotic cardiovascular morbidity. Endovascular treatment has become the principal surgical strategy in femoro-popliteal lesions. Stent placement induces significant changes in the arterial geometry and thereby in the hemodynamic environment. Visualization of local blood flow patterns (around stents) is challenging, but clinically relevant. Blood flow has a significant influence on the development of atherosclerosis and therefore stent patency. In vivo blood flow characterization might enable the recognition, prediction and explanation of (in-stent) restenosis. This study will therefore aim to investigate the feasibility of a novel ultrasound technique (echoPIV) to quantify spatiotemporal blood flow near stented femoral artery lesions. Furthermore, the blood flow information obtained during the echoPIV measurements will be used as patient-specific boundary conditions in a computational fluid dynamics (CFD) simulation. The tested hypothesis is that blood flow quantification using echoPIV is feasible in and around stents in the femoral artery and that it will improve CFD simulations.

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Key information

Conditions

Peripheral Arterial Disease Arterial Occlusive Diseases Arteriosclerosis Atherosclerosis Cardiovascular Diseases Peripheral Vascular Diseases Vascular Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Rijnstate Hospital

Arnhem, Gelderland, Netherlands

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Scheduled endovascular treatment of a lesion in the SFA through placement of a bare metal or a covered stent
  • A recently (<6 weeks) treated lesion in the SFA through placement of a bare metal or a covered stent

Exclusion criteria

  • Hypersensitivity to the active substance(s) or any of the excipients in SonoVue
  • Right-to-left cardiac shunt
  • Severe pulmonary hypertension (pulmonary artery pressure > 90mmHg)
  • Uncontrolled systemic hypertension
  • Adult respiratory distress syndrome
  • Severe pulmonary disease (e.g. COPD GOLD 3/4, adult respiratory distress syndrome)
  • Clinically unstable cardiac disease (recent or ongoing myocardial infarction, unstable angina at rest, recent percutaneous coronary intervention, clinically worsening cardiac symptoms, severe cardiac arrythmia's, endocarditis, etc.)
  • Prosthetic valves
  • Loss of renal function (GFR < 31 ml/min), end-stage renal disease
  • End-stage liver disease Sepsis
  • Hypercoagulable status, recent thrombosis
  • Congestive heart failure (class III or IV)
  • Hypersensitivity to iodinated contrast media
  • Pregnancy

Treatment and study plan

High-frame-rate contrast-enhanced ultrasound measurements (echoPIV)

Diagnostic Test

Patients will undergo high-frame-rate contrast-enhanced ultrasound measurements, within 6 to 8 weeks after the endovascular procedure, at the vascular center of Rijnstate hospital. Prior to these measurements a venous cannula will be placed to ensure venous access for the contrast administration.

Computed tomography angiography (CTA) scan

Diagnostic Test

Patients will undergo a CTA scan of the lower extremities at the Radiology dept. of Rijnstate hospital the same day as the echoPIV measurements. This CTA scan serves as a reference for the vessel geometry and stent location.

Primary outcomes

  1. Qualitative assessment vector velocity fields

    Time frame: 6 to 8 weeks after the procedure (stent placement of SFA)

    Vector velocity fields derived from the echoPIV data will be used to calculate and visualize the velocity profile. In order to answer the question regarding feasibility of echoPIV the quality of the vector velocity fields will be assessed using three different metrics of which the first one is a qualitative assessment by different observers. Recordings of the contrast-enhanced ultrasound with an overlay of the vector velocity profiles will be reviewed on different topics following a scoring rubrics.

  2. Contrast-to-background ratio

    Time frame: 6 to 8 weeks after the procedure (stent placement of SFA)

    The contrast-to-background ratio (CBR) is the second metric to assess the outcomes of the echoPIV measurements. The CBR is a quantitative measure for the contrast levels and therefore for the quality of the contrast-enhanced US image. The higher the CBR level (in dB) the higher the intensity of the contrast which is needed for sufficient PIV analysis.

  3. Vector correlation

    Time frame: 6 to 8 weeks after the procedure (stent placement of SFA)

    The vector correlation is the third metric to assess the outcomes of the echoPIV measurements. The vector correlation demonstrates the tracking performance of the PIV algorithm. The vector correlation provides a unitless value between 0 and 1 in which 0 indicates poor tracking of the microbubble contrast and 1 indicates perfect tracking of the microbubble contrast.

Secondary outcomes

  1. Vorticity

    Time frame: 6 to 8 weeks after the procedure (stent placement of SFA)

    Multiple blood flow parameters will be derived from the echoPIV data. The first one is the vorticity, or the curl of the velocity. The vorticity represents the rotation of particles inside the flow field. This measure can potentially be used to define regions with disturbed blood flow, as a high value (in rad/s) indicates the occurence of a recirculation.

  2. Vector complexity

    Time frame: 6 to 8 weeks after the procedure (stent placement of SFA)

    The second blood flow parameters derived from the echoPIV data is the vector complexity. Vector complexity is a measure of multi-directional flow, ranging from 0 till 1. a value of 1 means complex flow with all velocity vectors pointing in all directions, whereas a value of 0 means laminar flow with all velocity vectors pointing in the same direction. This measure can potentially be used to indicate regions with disturbed blood flow.

  3. Correlation echoPIV and CFD

    Time frame: 6 to 8 weeks after the procedure (stent placement of SFA)

    Velocity profiles obtained with echoPIV will be compared to outcomes of a computational fluid dynamics (CFD) simulation model of the femoral artery. Multiple points along the imaged vessel will be selected in both the echoPIV and the CFD data to extract the temporal velocity profile. This profile will be compared point-by-point after which the correlation between both outcomes/techniques will be obtained.

Sponsors and collaborators

Lead sponsor

Rijnstate Hospital

Other

Registry information

Official study title

Feasibility of Ultrasound Particle Image Velocimetry to Quantify Flow Near Stented SFA Lesions

Acronym: EchoPIV in SFA

Important dates

Study start
2018
Primary completion
2019
Study completion
2019
First posted
Jun 22, 2021
Registry last updated
Jun 22, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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