Points

1
Professional Standards Committee report 2007
Manchester Mohammed Aslam Sonia Charles Theresa
fail Timothy Hartshorne Keith Humphries Pouran
Khodabakhsh Crispian Oates
2

• The following slides were presented at the SVT
  AGM, Manchester 2007
• Feedback concerning the carotid consensus is very
  welcome. Please contact
• tim.hartshorne_at_uhl-tr.nhs.uk

3
Key activity

• Newsletter and journal reviews
• Standards and guidelines for the DH, PM group.
• Carotid Endarterectomy Audit of Great Britain and
  Ireland
• Recommendations for the standardised reporting of
  carotid artery disease by ultrasound.
  Collaboration with VS apointed expert Professor
  AR Naylor

4
CEA audit GBI

• Funded by the Healthcare Commission
• The Vascular Society and Royal College of
  Physicians
• To assess the speed of delivery
• To assess variations in provision of imaging and
  CEA
• To assess 30-day mortality and follow up

5
CEA audit GBI

• Interim report published
• Suggest that the response to symptoms and
  professionals is too slow
• Majority of imaging by duplex
• The majority of cases are for gt70 NASCET lesions

6
The following statements have appeared in
National Journals and underline the need for the
development of a National Consensus or Standards
document   Although the majority of respondents
to Walkers and Naylors Questionnaire did not
know or wrongly knew what measurement methods
they were using, it was clear that they were
indeed adopting PSV and EDV validated by the
North American consensus (NASET criteria)   The
current study (despite its limitations) suggest
that there is too much confusions and
considerable variability in diagnostic thresholds
to allow this practice to continue
unchallenged.   While the NASCET method of
measurement may not reflect the burden of
atherosclerosis in the proximal ICA, it does
minimize the amount of interobserver variability
7
The SVT/VS document will include this table for
conversion purposes
8
Ultrasound based measurement carotid stenosis
gt70 an audit of UK practice. Walker J and
Naylor AR. Eur J Vasc Endovasc Surg 2006
31(5)487-90
NASCET
ECST
Dont know
9
The American consensus document
Carotid Artery Stenosis Gray-Scale and Doppler
ultrasound diagnosis-Society of Radiologists in
Ultrasound Consensus Conference. Grant EG et al.
Radiology 2003229340-46
10
Key references for SVTGBI VS standards
Carotid Artery Stenosis Gray-Scale and Doppler
ultrasound diagnosis-Society of Radiologists in
Ultrasound Consensus Conference. Grant EG et al.
Radiology 2003229340-46 Ultrasound assessment
of internal carotid artery stenosis. Sidhu PS and
Allan PJ Clinical Radiology 199752654-658 Duple
x ultrasound criteria for defining the severity
of carotid stenosis. Filis KA et al Annals of
Vascular Surgery 200216413-421 Angiographic
and Duplex Grading of Internal Carotid Stenosis
Can we overcome the confusion? Nicolaides AN,
Shifrin EG, Bradbury A, Dhanjil S et al J
Endovasc Surg 19963158-165
11
An attempt to standardize the practice of grading
carotid artery disease. NASCET method of grading
SVT/VS recommendations  
gt125
2-4
12
Caution 1
Large plaques in wide carotid bulbs represent a
potential grading problem as the peak systolic
velocity may be below threshold for a 70
stenosis but the plaque may occupy more than 70
of the bulb volume. In this situation the
diameter of the residual should be compared with
the total diameter of the bulb and included in
the report.
13
Caution 2
ICA
ECA
Loss of cerebrovascular compliance with
associated stiffening of the arterial walls can
result in abnormally high systolic velocities
throughout the carotid system. Wide variations
between peak and end diastolic velocity from
discrete points along the CCA and proximal ICA
are suggestive of this condition and care should
be exercised in grading any stenoses as
overestimation is possible.
14
Caution 3
Namely, to beware of abnormal waveforms or absent
or greatly reduced CCA diastolic flow on both
sides which may indicate the presence of inflow
disease or aortic valve regurgitation.
15
Other consideration

• Angle 60 degrees or less
• Minor disease lt50 NASCET
• Sample volume size
• Reporting requirements
• Quality assurance
• Machine variability
• Consultation with manufactures