QUAMUS: Ultrasonographic Morphology Assessment of Low-grade Carotid Stenosis

Sponsor

Centre Hospitalier Intercommunal de Toulon La Seyne sur Mer (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT05437991

Collaborator

(none)

Enrollment

Location

Arm

Anticipated Duration (Months)

7.5

Patients Per Site Per Month

Study Details

Study Description

Brief Summary

Internal carotid artery (ICA) is intended to supply blood to brain. The carotid bulb located upstream of ICA origin is prone to atherosclerosis. This is an accumulation of fat and calcium in the wall forming a plaque that gradually thickens and leads to carotid stenosis (CS), which causes a decrease in blood flow. The risk of CS is stroke caused either by carotid artery thrombosis (occlusion) or by atherosclerotic plaque fragmentation, some components of which may leak into the brain (embolism).

When diagnosing CS, an Echo-Doppler is performed to determine bulb and ICA origin obstruction rates. The reference method of quantifying CS is based on hemodynamic criteria that only allow the diagnosis of high grade stenosis thresholds (50%-70%). Below 50%, low-grade stenosis, patient follow-up is limited and could be based on morphological criteria; ultrasound imaging being a reference technique for human body structures morphological assessment, especially vessels.

Two methods of CS morphological quantification with Doppler ultrasound currently exist. Calibre reduction at the maximum of stenosis can be measured by relating the smallest luminal diameter to the vessel diameter at stenosis site (ECST method) or to the downstream ICA diameter (NASCET method). As bulb diameter measures ≈1.8 times that of ICA, ECST appears to be more suitable for CS quantification. For high-grade stenosis, morphological quantification performance is impaired due to extensive calcification of large atheromatous plaques. However, it is possible that less calcified nature of low-grade stenosis and the use of a rigorous methodology will allow reproducible assessment in routine practice. This technique has not yet been evaluated, although it is a frequent situation in patient follow-up.

Condition or Disease	Intervention/Treatment	Phase
Carotid Stenosis	Diagnostic Test: Independent morphological quantifications by echo-doppler using ECST method	N/A

Detailed Description

Internal carotid artery is intended to supply blood to brain. The carotid bulb located upstream of internal carotid artery origin is prone to atherosclerosis. This is an accumulation of fat and calcium in the wall, forming a plaque which gradually thickens and leads to carotid stenosis, causing a reduction in blood flow. The risk of carotid stenosis is stroke caused either by carotid artery thrombosis (occlusion) or by atherosclerotic plaque fragmentation, some components of which may leak into the brain (embolism).

When carotid stenosis is diagnosed, an Echo-Doppler is performed to determine the bulb and internal carotid artery origin obstruction rates. The reference method for quantifying carotid stenosis is based on hemodynamic criteria that only allow the diagnosis of high grade stenosis thresholds (50%-70%). Below 50%, low-grade stenosis, patient follow-up is limited and could be based on morphological criteria; ultrasound imaging being a reference technique for human body structures morphological assessment, especially vessels.

Two methods of carotid stenosis morphological quantification with Doppler ultrasound currently exist. Calibre reduction at the maximum of stenosis can be measured by relating the smallest luminal diameter to the vessel diameter at stenosis site ("European Carotid Surgical Trial" (ECST), European method) or to the downstream internal carotid artery diameter ("North American Symptomatic Carotid Endarterectomy Trial" (NASCET), North American method). As bulb diameter measures ≈1.8 times that of the internal carotid artery, the NASCET appears to be more suitable for carotid stenosis quantification. For high-grade stenosis, morphological quantification performance is impaired due to extensive calcification of large atheromatous plaques. However, it is possible that less calcified nature of low-grade stenosis and the use of a rigorous methodology will allow reproducible assessment in routine practice.

This technique has not yet been evaluated although it is a frequent situation in patient follow-up. This study therefore suggests to evaluate the inter-observer reproducibility of morphological quantification of these stenosis by the ECST method with a precise methodology.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

83 participants

Allocation:

N/A

Intervention Model:

Single Group Assignment

Masking:

None (Open Label)

Primary Purpose:

Diagnostic

Official Title:

Ultrasonographic Morphology Assessment of Low-grade Carotid Stenosis

Anticipated Study Start Date :

Jul 1, 2022

Anticipated Primary Completion Date :

Jun 1, 2023

Anticipated Study Completion Date :

Jun 1, 2023

Arms and Interventions

Arm	Intervention/Treatment
Other: Morphological quantification of low-grade carotid stenosis Morphological quantification using ECST method and implying two independent observers	Diagnostic Test: Independent morphological quantifications by echo-doppler using ECST method The physician who is usually in charge of patient follow-up performs a first evaluation of carotid stenosis percentage by echo-doppler using ECST method. Then a second physician immediately performs a second evaluation using the same echo-doppler device without knowing first evaluation conclusions.

Arm

Intervention/Treatment

Other: Morphological quantification of low-grade carotid stenosis

Morphological quantification using ECST method and implying two independent observers

Diagnostic Test: Independent morphological quantifications by echo-doppler using ECST method

The physician who is usually in charge of patient follow-up performs a first evaluation of carotid stenosis percentage by echo-doppler using ECST method. Then a second physician immediately performs a second evaluation using the same echo-doppler device without knowing first evaluation conclusions.

Outcome Measures

Primary Outcome Measures

To evaluate the inter-observer reproducibility of morphological quantification of low-grade carotid stenosis (<50%) using the ECST method [1 day]
Each operators will perform stenosis percentage calculation according to ECST method. Between the two calculations performed independently by the two observers, a difference of ±10% will be considered acceptable.

Secondary Outcome Measures

To assess the performance of morphological quantification technique according to examination feasibility (good, medium, poor). [1 day]
The examination feasibility will be based on subjective assessment of the conditions under which the measurements are made (systolic and diastolic velocities in the internal carotid artery, diameter of the patent lumen, diameter of the vessel at the site of stenosis): Good: no doubt about measurements accuracy Medium: more difficult to make accurate measurements Poor: significant doubt about measurements accuracy

Eligibility Criteria

Criteria

Ages Eligible for Study:

18 Years and Older

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Inclusion Criteria:

Outpatient referred for Echo-Doppler exploration of the neck vessels
Patient 18 years of age or older
Atheromatous arterial disease with stenosis < 50% (maximum systolic velocity < 125 cm/sec for an angle of 50-60°) in at least one carotid artery

Exclusion Criteria:

Patient refusal
Unavailability of two physicians to perform examination
Patient under judicial protection (guardianship, curators...) or justice safeguard
Pregnant, parturient or breastfeeding woman
Any other reason that could interfere with study objectives evaluation in the investigator opinion