Duplex ultrasound Findings in Carotid Artery Stenosis

Transcription

1 Duplex ultrasound Findings in Carotid Artery Stenosis The 7th Annual Congress of the LSVS, Beirut Pascal Giordana 1

2 Liens d intérêt Siemens Esaote Hitachi Mindray Aspen Bayer Boehringer Ingelheim BSN Radiante Daiichi-Sankyo Innothéra Léo Pharma Médi France Pfizer Sigvaris Thuasne Pas de conflit d intérêt pour cette communication 2

3 The arisen of neurological events was correlated for a long time with the degree of CAS It is estimated with duplex scan (1): maximale systolique vitesse: MSV end diastolic vitesse: EDV carotido-carotidien rapport: CCR Degré de sténose VMS (cm/sec) RCC VTD (cm/sec) Normal <140 <2 <40 50 à 69% à 4 40 à % >230 >4 >100 End diastolic speeds report can be also used and allows a 100% reliability(2) 1. Grant E.G et al. : Radiology 2003 ; 229 : Carpenter J.P et al. : J Vasc Surg: 1995; 22: Aburahma et al : JVS

4 Planimetric criteria in ultrasound, even by using the color doppler or energy mode, are only less reliable. A conflict must induce a discussion about an error of measure or an associated pathology modifying the flow velocities (1). Becker F 1. Baud J.M. et Becker F.: traité de médecine vasculaire Tome 1 ; pages

5 Stenosis severity was predictive of increased risk of late stroke 50 69% stenose incured a 0.8% annual risk of ipsilateral stroke 70 89% stenose incured a 1.4% annual risk of ipsilateral stroke 90 99% stenose incured a 2.4% annual risk of ipsilateral stroke Nicolaides AN et al. : Eur J Vasc Endovasc Surg, 2005; 30; Stenosis progession was associated with a twofold increase in the 3-years risk of stroke 2.5% to 5% [ OR 2.00 (95% CI, )] Sabatei S et al. : Stroke 2007; 38;

6 End of 80 s and 90 s: Morphology of carotid plaques is done by visual (subjective) grading of echo-reflexion (echogenicity / echolucency) and echo pattern (heterogenous / homogenous) (1): Classe I Classe II echolucent Classe III Classe IV Classe V echogenic calcifications Classification de Gray-Weale (1988) Geroulakos (1993) 1. Steffen C.M, Gray Weale A.C et al. : Aust NZ J Surg 1989 jul ; 59 (7) : Geroulakos et al. : Br J Surg. 1996May ; 83 (5) ;

7 RCA plaque, Sonde 9L4 Hight resolution ultrasound imaging can be useful RCA plaque, Sonde 18L6 HD 7

8 Plaques echolucencies make more occular events (1) Echolucency independantly increased the risk of neurovascular events (2) Echolucency increased the risk of cardio vascular events(3) The plaque is stable if calcification aera > 45% (4) Combination of plaque echolucency and being embolus positive, significantly increased the rate of ipsilatral stroke (OR 10.6) (5) 1. Tegos T.J et al.: Am J Neuroradiol 2000 Nov-Dec: 21 (10): Mathiesen E.B et al.: Stroke 2001 sep; 32(9): Honda et al.: Vasc Health Risk Manag June; 1(2): Nadalur K.R et al.: Stroke 2007 Mar;38(3): Topakian R et al: Neurology 2011; 77;

9 The detection of micro embolic signals has a potential in stroke risk stratification, evaluating the effect of new anti-thrombotic therapies and in peri-operative and remote monitoring of carotid endarterectomy. Keunen RW et al: J Med Eng Technol (4);

10 90 s: computerized plaque analysis after normalization of image data: GSM (Gray Scale Median) (1-5). It s a a computerized, objective measurement of the gray values of pixels after image normalization. The blood (black) egal 0 The adventice (white) egal 190 The lower the GSM the more echolucent is the plaque. The echogenic plaque will have a higher GSM 1. El Barghouty N. et al.: Eur J Vasc Endovasc Surg 9, (1995) 2. El Bargouty N et al.: Eur J Vasc Endovasc Surg 11, : El Barghouty N. et al.: Eur J Vasc Endovasc Surg 11, : Elatrozy T et al.: int Angiol Sept; 17 (3): Elatrozy T. et al. : Euro J Vasc Endovasc Surg 16, :

11 Normalization of image data and measurement of the GSM GSM = 64 11

12 Values of the GSM estimate. : 0 et 5 for the blood, 8 et 26 for lipid, 41 et 76 for the muscle, 112 et 196 for the fibrous tissues 211 à 255 for calcification Brajesh K. Lal et al.: J Vasc Surg 2002;35:

13 The mean limitation of this technic depends of the acquisition s value: machine, probe, adjustement. That explain the cut-off variability to definite asymptomatic versus symptomatic plaque. Auteur Symptomatic plaque GSM Asymptomatic plaque GSM El Barghouty <32 >32 Elatrozy 21 ± 16 37,6 ± 26 Gronholdt <74 >74 Lal 32 ± 7,5 49,3 ± 6,7 Grogan 41 ± 9 60 ± El Barghouty et al.: Eur J Vasc Endovasc Surg 1996 ;11 : Elatrozy T et al. : int Angiol sep;17(3): Gronholdt M.L et al.: circulation 1998;97: Lal Brajesh K et al. : Ann vasc Surg 2006 ; 20 : Grogan J.K et al.: J Vasc Surg, 42 (2005),pp

14 In the ACSRS study: Asymptomatic plaque with a GSM > 30 had a very low annual rate of stroke (0.6%). The annual rate of stroke increased to 1.6% in patients with GSM of 15 to 30 Patients with GSM < 15 had a 3.6% annual risk of stroke. Nicolaides A et al: J Vasc Surg 2010; Plaque echolucency (nor severity of stenosis) was predicitve of ipsilateral stroke or death among 111 asymptomatic patients with 50 99% stenoses who were followed for 4.4 years. Gronholdt M.L. et al: circulation 2001; 104;

15 In the ACSRS study the plaque area parameter and the juxta luminal black area were used. The plaque area is calculated by the imaging software using the distance scale on the side of the image frame for calibration and the plaque area outlined by the operator. Asymptomatic patients with 50 99% stenoses who had a plaque area < 40 mm² had a low annual rate of stroke (1%) Increased to 1.4% in patients plaque area of mm² Highest annual rate of stroke was observed in patients with a plaque area > 80 mm² (4.6%) Nicolaides AN et al: J Vasc Surg 2010;

16 In the ACSRS study the plaque area parameter and the juxta luminal black area were used. The largest juxta-luminal black area (JBA) of the image, defined as the plaque plaque area with pixels having a gray-scale < 25 without echogenic cap, was outlined and express as mm² (necrotic core, lipid, hemorrhage, thrombus). The JBA < 4 mm² was associated with a 0,4 % annual risk of stroke Increased to 1.4% when JBA was 4 8 mm² Highest annual rate of stroke was observed in patients with a JBA 8 to 10 mm² (3.2 %) and > 10 mm² (5%) Nicolaides AN et al: J Vasc Surg 2010;

17 Patients with a combination of plaque area > 95 mm² and a JBA > 6 mm² had a 90% probability of having a histologically unstable carotid plaque. Salem MK et al: Eur J Vasc Endovac Surg 2014; 48;

18 Plaque classification using computer normalization: Type 1: uniformly echolucent (black): < 15% of the pixels in the plaque area was occupied by pixels with GSM > 25 Type 2: mainly echolucent: pixels with GSM > 25 occupy 15 50% of the plaque area Type 3: mainly echogenic: pixels with GSM > 25 occupy 50 85% of the plaque area Type 4: uniformly echogenic: pixels > 25 occupy > 85% of the plaque area Nicolaides AN et al: Vascular 2005; 13;

19 Subject with plaque irregularity had an age-adjusted increase in late stroke [ OR 7.7 (2 30)] Kitamura A et al: Stroke 2004; 35; Having bilateral plaque irregularity significantly increased the risk of long-term stroke compared with unilateral plaque irregularity [ OR 3.9 (1.4 11)] Prabhakaran S et al: Stroke 2006; 37; Using High-resolution ultrasound: The presence of three or more micro-plaques ulcers (in total of both carotid artery plaques) was associated with signifcant increase in stroke/death at 3 years compared with patients who had fewer or no ulcers (18% vs 2%, p = 0.03) Madani A et al: Neurology 2011; 77;

20 Predicting of annual risk of stroke in patients with 50 79% or 80 99% asymptomatic carotid stenosis (NASCET measurement method): Stenose severity Presence or absence of prior controlateral symptoms Plaque aera Gray Scale Median (GSM) Naylor A. R. et al: Eur J Vasc Endovasc Surg (2014) 48,

21 Contrat-enhanced ultrasound imaging can help in the analysis of polygon of Willis to detect tandem stenosis Thrombosis of right MCA 21

22 Inflammatory theory, years 90 s s Parietal contraints Hypoxie Free radicals Oxidation Smooth cells inflammation Macrophages Lymphocytes IL6, IL10 22

23 Neovascularization from vaso-vasarum and from the vascular lumen Intra plaque bleeding 23

24 CE-US. The same hemodynamical characteristics as blood with wich they are mixed Small vessels and low flow No extravasation (1). Contrast enhencement is proportional to the neovascularization intensity Tranquart F. et al: Echographie de contraste: méthodologie et applications cliniques (édition Springer, Paris 2007) 24

25 The mural vascularization Intra plaque hematoma 25

26 Ruptured plaque 26

27 Shah (2007) Huang (2008) Coli (2008) Giannoni (2009) Li Xiong (2009) Vincenzini (2009) Staub (2010) Correlation between enhancement and the neovascularization intensity Enhancement vs echolucency Grade I: marginal enhancement Grade II: massiv enhancement Correlation with symptomaitc plaque Marker of independant risk (neuro-vascular) More intense compared to ulceration Marker of independant risk (cardio-vascular) 1. Shah F. et al : Vascular medicine 2007; 12: Pin-tong Huang et al: Journal of Clinical Ultrasound,vol 36, N 6, July/August 2008, Coli et al: JACC 2008;52: Giannoni M.F. et al: Eur J Vasc Endovasc Surg,2009, 37, Li Xiong et al: Radiology: Volume 251: Number 2 May 2009; Vincenzini E. et al: Cerebrovasc Dis, 2009;27 (suppl 2); Staub D et al: Stroke 2010; 41;

28 Conclusions (I): First intention Several informations which can be useful for diagnosis and follow up: Quantification: Severity of the stenosis Tandem stenosis or bilateral stenosis Progression of the stenosis Intra cranial consequences: Vasoreactivity Micro embol signals 28

29 Conclusions (II): Morphology: Echogenic vs echolucent plaque (subjective or objective evaluation) Homogenous vs heterogenous Regular vs irregular (ulcerations) Plaque aera and juxta-luminal black area (JBA) Neovascularization 29