The stroke risk reduction benefit of surgical intervention in carotid occlusive disease has been validated in multicenter trials for various angiographically defined lesion severity categories. The two divergent angiographic grading methods used for internal carotid artery stenosis in these trials have caused confusion in the clinical application of their recommendations. Moreover, while today's highly accurate carotid duplex scanning can obviate the need for preoperative angiography in many cases, the duplex criteria must be tailored to achieve sufficiently reliable results on which therapeutic decisions can be made. This review offers a clarification of the discrepancies between the angiographic grading techniques and how their measurements of percent stenosis correlate to the duplex criteria needed to support the treatment decision-making process for carotid obliterative disease.
GeeWMehiganJTWylieEJ. Measurement of collateral cerebral hemispheric blood pressure by ocular pneumoplethysmography. Am J Surg1975;130:121–127.
2.
LangloisYERoedererGOChanATW. Evaluating carotid artery diseases: The concordance between pulsed Doppler spectrum analysis and angiography. Ultrasound Med Biol1983;9:51–63.
3.
RoedererGOLangloisYEYaegerKA. A simple spectral parameter for accurate classification of severe carotid disease. Bruit1984;8:174–178.
SumnerDS. Evaluation of noninvasive testing procedures: Data analysis and interpretation. In: BernsteinE, ed. Vascular Diagnosis, 4th ed.St. Louis, Mosby, 1993:39–63.
6.
GelabertHAMooreWJ. Carotid endarterectomy without angiography. Surg Clin North Am1990;70:213–223.
7.
FarmiloRWScottDJAColeSEA. Role of duplex scanning in the selection of patients for carotid endarterectomy. Br J Surg1990;77:388–390.
8.
Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. JAMA1995;73:1421–1428.
North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. N Engl J Med1991;325:445–453.
11.
European Carotid Surgery Trialists Collaborative Group. MRC European carotid surgery trial: Interim results for symptomatic patients with severe (70–99%) or with mild (0–29%) carotid stenosis. Lancet1991;337:1235–1243.
12.
BarnettHJMWarlowCP. Carotid endarterectomy and the measurement of stenosis. Stroke1993;24:1281–1284.
13.
RothwellPMGibsonRJSlatteryJ. Equivalence of measurements of carotid stenosis. Stroke1994;25:2435–2439.
14.
BladinCFAlexandrovAVMurphyJ. Carotid stenosis index: A new method of measuring internal carotid artery stenosis. Stroke1995;26:230–234.
15.
EliasziwMSmithRFSinghN. Further comments on the measurement of carotid stenosis from angiograms. Stroke1994;25:245–249.
16.
BladinCFAlexandrovAVNorrisJW. Measurement of carotid stenosis, (letter)Lancet1994;344:750.
17.
De BrayJMGlattB. Quantification of atheromatous stenosis in the extracranial internal carotid artery. Cerebrovasc Dis1995;5:414–426.
18.
WilliamsMANicolaidesAN. Predicting the normal dimensions of the internal and external carotid arteries from the diameter of the common carotid. Eur J Vasc Surg1987;1:91–96.
19.
NorrisJWAlexandrovAVBladinCF. Progress in evaluating carotid artery stenosis. J Vasc Surg1995;22:637–638.
20.
Clinical Alert to ECST Participants, September 1995.
21.
RobinsonMLSacksDPerlmutterGS. Diagnostic criteria for carotid duplex sonography. AJR1988;151:1045–1049.
22.
MonetaGLEdwardsJMChitwoodRW. Correlation of North American Symptomatic Carotid Endarterectomy Trial (NASCET) angiographic definition of 70% to 99% internal carotid artery stenosis with duplex scanning. J Vasc Surg1993;17:152–159.
23.
MittlRLBroderickMCarpenterJP. Blinded-reader comparison of magnetic resonance angiography and duplex ultrasonography for carotid artery bifurcation stenosis. Stroke1994;25:4–10.
24.
ZweibelWJ. Spectrum analysis in carotid sonography. Ultrasound Med Biol1987;13:625–636.
25.
GarthKECarrollBASommerFG. Duplex ultrasound scanning of the carotid arteries with velocity spectrum analysis. Radiology1983;147:823–827.
26.
MonetaGLEdwardsJMPapanicolaouG. Screening for asymptomatic internal carotid artery stenosis: Duplex criteria for discriminating 60% to 99% stenosis. J Vasc Surg1995;21:989–994.
27.
WilliamsMADeaconDFSzendroG. Duplex scanning in detection and grading of internal carotid artery stenosis improved criteria. In: NicolaidesANSalmasiMA, eds. Cardiovascular Applications of Doppler Ultrasound. New York, Churchill-Livingstone, 1989:247–260.
28.
KnoxRAGreeneFMBeadeK. Computer based classification of carotid arterial disease: A prospective assessment. Stroke1982;13:589–594.
29.
SteinkeWHennericiMRautenbergW. Symptomatic and asymptomatic high grade carotid stenosis in Doppler color flow imaging. Neurology1992;42:131–137.
30.
SitzerMFürstHSFisherH. Between-method correlation in quantifying internal carotid stenosis. Stroke1993;24:1513–1518.
31.
De BrayJMGallandFLhosteP. Color Doppler imaging duplex sonography and angiography of carotid bifurcations. Prospective and double blind study. Neuroradiology1995;37:219–224.
32.
FurstHS. Echo-enhancing agents. Carotid imaging (Abstr.). Int Angiol1995;14(Suppl 1):41.
