Carotid artery disease is a major cause of stroke. Left untreated, carotid stenosis over 75% carries a risk of stroke of 2-5% per year. Carotid endarterectomy has been shown in clinical trials such as NASCET and ACAS to significantly reduce stroke risk compared to medical management alone, with perioperative stroke or death rates of less than 6% for symptomatic patients and 3% for asymptomatic patients. Carotid artery stenting is an alternative treatment that utilizes embolic protection devices and stent placement to treat carotid stenosis, but requires technical expertise to achieve outcomes comparable to surgery.

3. Carotid Stent
IMPORTANCE
OF
CAROTID ARTERY
DISEASE
TREATMENT

4. Carotid Stent
Stroke:
• 3rd cause of death in US
• 500,000 cases/year
• 2 milion/year handicaped people
HIGH SOCIAL / ECONOMIC COST
Mellière et al. J Mal Vasc, 1993

5. Carotid Stent
• 20 - 30% of VCA are related to
carotid occlusive disease
• Increased incidence with age
(33% < 45 yrs and 80% >50 yrs)
De Bakey et al. J Endovasc Surg, 1996

6. Carotid Stent
• Stenoses > 75%
risk of stroke in 1st yr = 2-5%
Roederer et al. Stroke, 1984
Hennereci et al. Brain, 1987
• Ulceration = Iminent stroke
risk of stroke = 7,5%
Autret et al. Lancet, 1987

7. Carotid Stent
• Carotid stenosis + TIA
• Risk of stroke in 1st yr = 12-13%
5th yr = 30-37%
Sundt et al., 1987
Dennis et al. Stroke, 1990
• CVA - risk in 1st yr = 59%
5th yr = 25-45%
Sacco et al. Stroke, 1982
Meissner et al. Stroke, 1988

8. Carotid Stent
• Heterogeneous and ulcerated lesions
= Risk 2-4 x
Langsfeld et al. J Vasc Surg, 1989
Sterpetti et al. Stroke, 1988

9. Carotid Stent
SURGICAL
TREATMENT

10. Carotid Stent
ENDARTERECTOMY (1953)
– risk of stroke
–TIA = 1-2% / Yr
–CVA = 2-3% / Yr

11. Carotid Stent
• Clinical Trials such as NASCET/ACAS
established the patern of eficacy of surgical
treatment in comparison to clinical
treatment
• Demonstrated the superiority of the method
with defined statistical criteria
• Surgery is the ¨gold standard¨ for low risk
pacients

12. Carotid Stent
NASCET (North American Symptomatic
Carotid Trial)
• 559 symptomatic patients
• stenoses > 70%
• Risk of CVA
Clinical treatment = 13,1%
Surgical treatment = 2,5%
P < 0,001
N Engl J Med 1991;325:445

13. Carotid Stent
NASCET (North American Symptomatic Carotid Trial)
 Risk CVA/peri-operatory death = 5,8%
 Benefits of surgery evident after 3 months
 Benefits for lesions > 50%
N Engl J Med 1991;325:445

14. Carotid Stent
ECST (European Carotid Surgery Trials)
• 778 symptomatic patients / 3 yrs
• stenoses > 70%
• Risk of CVA
Clinical treatment = 16,8%
Surgical treatment = 2,8%
p < 0,001
• Risk CVA/peri-operatory deaths =7,5%
Lancet 1991;337:1235

15. Carotid Stent
ACAS (Asymptomatic Carotid Atherosclerosis Study)
• 1662 asymptomatic patients / 5 yrs
• stenoses > 60%
• Risks of CVA
Clinical treatment =10,6%
Surgical treatment = 4,8%
P < 0,004
• Risk CVA/peri-operatory death = 2,3%
Stroke 1994; 25: 2523-2524

16. Carotid Stent
AHA Quality Standards
Surgical Treatment
CVA / Death
• Symptomatic Patients < 6%
• Asymptomatic Patients < 3%

17. Carotid Stent
NASCET (North American Syntomatic Carotid Trial)
 Cranial Nerve Lesion : 7,6%
 Hematoma : 5,5%
Extensive list of exclusion criteria !
N Engl J Med 1991;325:445

18. Carotid Stent
Exclusion Criteria - NASCET / ACAS
• age > 79 anos
• co-morbidity (cardiac/renal/hepatic/ca)
• valvulophaty / arrithmias
• previous endarterectomy
• unstable angina / recent MI
• previous surgery (30 days)

45. Tools & Techniques
• The benchmark for perioperative stroke or
death for carotid revascularisation is the limit
of 6% for symptomatic pts.
• and
• 3% for asymptomatic patients.

46. How to achieve good outcomes…
• 1. A “tailored-approach”-
The application of endovascular
technologies and techniques to a specific-
patient with a specific lesion and vascular
anatomy.

47. • 2. The choice of stent, embolic protection
device (EPD), guidingcatheter and sheath is
strongly dependant on an in-depth knowledge
of neuro-assessment, carotid plaque
characteristics,vascular anatomy and technical
features of a vast array of endovascular
materials.

48. • 3. Experience with a wide range of devices
allows the operator the flexibility to choose
the most appropriate tools and techniques for
the safe application of CAS.

49. Carotid plaque and vascular anatomy
evaluations
• Length/bulk of disease and the morphologic
features that predict lesion complexity such as
degree of calcification and embolisation-
potential (“vulnerable plaque”).
• “soft-lesions”on B-mode ultrasound with GSM
<25.

50. (A) Angiographic aspect of an ulcerated carotid ultrasonographic appearance of
plaque (circle); (B) ulcerated portion in detail; a “soft” plaque

51. The assessment of vascular profile
• 1. Configuration of the aortic arch .
• 2. Arch embologenic-risk in terms of burden of
irregular, ulcerated and calcified atheroma .
3. Angulations and tortuosity, coiling and kinking
of supra- aortic trunks .
• 4. Level of carotid bifurcation and its anatomy
regarding angle of take-off of the internal carotid
artery (ICA), tortuosity at lesion-site and vessel
dimensions .
• 5.Intracranial segment of the ICA and
ipsilateral/contralateral cerebral circulation to
determine collateral flow including circle of Willis
and identify abnormal flow patterns.

52. Aortic arch anatomy
Type I (A), Type II (B) and Type III
(C) arches

53. Example of an aortic arch with high emboligenic-risk.
extense, irregular and calcified plaque in the aortic wall

54. Challenging anatomies of the supra-aortic trunks.
A bovine aortic arch configuration is where the LCC originates from the
brachiocephalic trunk

55. Challenging anatomies of the supra-aortic trunks
(C) proximal kinking followed by distal
(A) accentuated tortuosity of the tortuosity of the LCCA,
RCCA; (B) tortuosity of both (D) Kinking of the brachiocephalic trunk
followed by angulated common carotid
common carotid arteries; arteries in a bovine aortic arch.

56. (A - B) accentuated tortuosity of
the RICA (C) angulated take-off of the LICA

57. Intracranial ICA and ipsilateral/contralateral
cerebral circulation
A) Right AP intracranial angiogram A severe lesion (red dotted circle) at
. the ostium of the MCA requires
B) Right lateral intracranial treatment before approaching the
angiogram. carotid bifurcation.

59. Neuroprotection systems
•Embolisation occurs in all percutaneous cardiovascular
Interventions.
•It acquires more significance in the neurovascular territory.
• Carotid lesions contain friable ulcerated plaque and thrombotic
material that can embolise during endovascular or open surgery.
•Embolic particles are classified as either macroemboli (>100 μm)
or microemboli (<100 μm).
•Macroemboli, especially >200 μm, are usually associated with
clinical events;

60. Distal protection devices
• Filter devices can be classified based on the
relationship to the 0.014” guidewire.
“wire-mounted filters”.
“bare-wire filter systems”.
• Filters are positioned in a straight portion
of the ICA(“landing-zone”) in order to
optimise adaptation of the frame to
thevessel wal

61. Schematic of (A) concentric and (B) eccentric filters
illustrating the position of the wire in relation to the
basket.

63. LIMITATIONS OF DISTAL PROTECTION DEVICES
• 1.Unprotected crossing of the lesion in order to
deploy the device,especially in tight stenoses.
• 2.Not effective in trapping microemboli, limited
by pore size.
• 3. In tortuous, large or diseased distal ICA
anatomies incomplete wall apposition may allow
evenmacroemboli to bypass the system.
• 4. Debris may be dislodged during the recapture
phase (“squeezing effect”) of the procedure.
• 5. Filters may be an embolic source themselves
due to intimal damage at the landing zone.

64. Proximal protection devices
• Proximal occlusion devices interrupt or
reverse blood-flow in the ICA by preventing
antegrade flow from the CCA to the ICA and
retrograde flow from the ECA into the ICA.

65. • they offer the following advantages:
– 1. Crossing the lesion under protection with the
preferred guidewire.
– 2. Blocking both macro- and microemboli.
– 3.Navigation of the device in the distal ICA is not
required, thus reducing the risk of intimal
damage, spasm or dissection.

66. MO.MA™ (INVATEC S.P.A., RONCADELLE, ITALY

67. backpressure of >30 mmHg predicts tolerance to
flow- blockage.

68. Following postdilatation blood is aspirated and checked for debris
before deflatingthe balloons

69. NEUROPROTECTION SYSTEM™ (NPS) (GORE, NEWARK,
DE, USA)
(A) Global view of the system. The detail shows
the “balloon-sheath” and the “balloon-wire” B) The filter is positioned between the
both inflated in the CCA NPS-sheath and the venous sheath. (C) The
and ECA NPS “balloon-sheath”.

70. LIMITATIONS OF PROXIMAL PROTECTION
DEVICES
• The need for large femoral sheaths.
• Clamping intolerance.
– MEASURES TO PREVENT CLAMPING INTOLERANCE.
 hurry up in order to restore perfusion as soon as
possible.
positioning under protection a distal filter and then
deflating the balloons .
perform a step-by-step procedure in which the
balloons are inflated and deflated at each
procedural-step.
• Restricted use hurry up in order to restore
perfusionwith severe disease of the ECA or
CCA.

71. PROXIMAL PROTECTION DURING CAS: CLINICAL OUTCOMES
• The ARMOUR study is a pivotal US trial evaluating the
safety and effectiveness of the Mo.Ma system.
– 30-day major adverse cardiac and cerebrovascular events, was
2.3%. The device success rate was 98.2%.
• The DESERVE study(europe) is a Diffusion Weighted-MRI
based evaluation of the effectiveness of the Mo.Ma
system.
– Results awaited.
• EMPIRE is a prospective controlled single-arm
multicentre trial to evaluate the performance of
the NPS system.
• It enrolled 122 patients .
• The primary endpoint of 30-day stroke and death rate was
1.6%.

72. Carotid stent selection
A) Open-cell design. B) Closed-cell C) Straight and tapered-stent
design configurations.

73. Carotid lesion treated by open-cell stent
showing a high flexibility and conformability that respect the original
anatomy of the vessel.

74. Structural and functional characteristics
• COBALT-ALLOY WIRE.
• Advantages
– flexible delivery system,
– small free-cell area with
high scaffolding and wall-
coverage properties
– adaptability to the
changing diameter across
the bifurcation.
• disadvantaged
– tendency to straighten
the vessel and
foreshortening during
deployment.

76. Functional characteristics of the hybrid carotid stent

77. Carotid stenting step-by-step procedure
• Peri-interventional protocol
– PRE-PROCEDURE INVESTIGATIONS
• 1. Carotid duplex scan. MR or CT angiography is not
mandatory,however, during the early experience it may help plan
for a challenging intervention.
• 2. Independent neurological evaluation.
• PRE-MEDICATION
– Dual antiplatelet therapy with aspirin and clopidogrel, ideally,initiated
five days before the procedure; and continued for at least 30 days at
which time clopidogrel is usually discontinued.

78. GENERAL PROCEDURAL MEASURES
• 1.Head support and no sedation;
• 2.standard monitoring of vital parameters
along with neuro-evaluation during procedure
by simple communication and movement
parameters.
• 3. hydrated and maintain saline infusion.
• 4.Heparin intravenous or intra-arterial 70
U/Kg (ACT 200 to 300 seconds; with proximal
occlusion aim for 250 to 300 seconds).

79. ANTI-HYPERTENSIVE MEDICATION
• Anti-hypertensive medication is omitted on
the day of the procedure and during the early
days postprocedure.
• Restarted once hypotension resolves to
ensure no rebound hypertension.

80. Technique
• VASCULAR ACCESS
– The femoral approach is strongly recommended,
but in the presence of extreme tortuosity or
occlusion of the iliac arteries the radial/brachial
approach is feasible.
• BASELINE ANGIOGRAPHIC EVALUATION.
• Aortic arch angiography is undertaken with a
pigtail catheter (30°to 45° left anterior
oblique, LAO) to determine arch configuration
and embologenic-risk, and visualise the origins
of the supra-aortic vessels.
• 2. Selective bilateral extracranial angiograms.

81. • It is mandatory to perform an intracranial
angiogram.
• Four vessel angiography, carotids and vertebrals,
are indicated only where the complexity of the
case recommends it as mandatory.(adequacy of
the collateral circulation and the function of the
circle of Willis).

82. COMMON CAROTID CANULATION
• safe and stable engagement of the CCA is one of
the most important.
• this is a significant distinction between CAS and
coronary interventions as engagement of the
deep-seated supraaortic trunks is typically more
difficult and requires great expertise.
• JR4 catheter is adequate.
• For Type III arch or an angulated or bovine origin
of the left CCA a JB2 catheter is most commonly
used.

83. • Sometimes in complex Type III or bovine
arches a Simmons catheter is necessary.

84. Guiding catheter engagement
• 90-100 cm 8 Fr guiding-catheter is chosen
according to the aortic arch configuration.
• For complex anatomy an angulated guide such
as a Hockey-stick curve catheter is advanced
into the proximal CCA.
• For simple anatomy a 40° angled soft-tip
catheter is advanced to the mid-CCA over a
soft-angled 0.035” standard hydrophilic wire
positioned just below the bifurcation.

85. • The introduction of two, or possibly three,
0.035” wires in order to advance the catheter
in the presence of an unstable situation is
feasible.

86. Sheath placement

87. EPD MANAGEMENT
• filters are positioned at least 30 to 40 mm
distal to the target lesion.(to avoid
entrapment).
• Full and adequate wall apposition of filter
devices must be confirmed by angiography in
two projections.
• When using distal filter devices it is critical to
always visualise the position of the guiding
catheter.

88. PREDILATATION
• Predilatation is reserved for
very tight lesions,
heavily calcified
long fibrotic lesions.
• low profile coronary balloon.
– 2.5 to 3.5 mm diameter .
– 20 to 30 mm length, and inflated at nominal
pressure.9
– cutting balloon for heavily calcified plaques usually
with a diameter of 3.5 to 4.0 mm and inflated at
moderate pressure (8 atmospheres).

89. • Pre-treatment with 0.5 to 1 mg of intravenous
atropine is required at this stage and/or post
dilatation phase.
• A fundamental principle of balloon dilatation
in CAS is the application of nominal pressure
for a brief period (about five seconds).

90. STENT DEPLOYMENT
 use stents 1 to 2 mm larger than the widest
vessel diameter to be covered.
• The most commonly used stent size with
reference to the proximal CCA edge is 8 to 10
mm.
and
• in the case of tapered stents the most
common reference for the distal ICA edge is 6
to 8 mm.

91. POST DILATATION
• Sizing the balloon according to the ICA at the
distal stent edge to prevent dissection and
squeezing of material through the stent mesh.
• Balloons no larger than 5.5 mm should be
used.
• The most common sizes required are 5.0 and
5.5 mm by a length of 20mm

92. • 10-30% residual stenosis is accepted.
• The stent segment in the CCA does not require
post dilatation.
• If plaque prolapses through the stent struts
(cheese-grater effect) no further balloon
dilatations should be performed and a second
stent, preferably a closed-cell stent should be
implanted.

93. FINAL ANGIOGRAPHIC EVALUATION
• acquired in the same baseline projections.
• If a distal protection device was used the
landing-zone has to checked carefully,
• Ipsilateral intracranial angiography should be
routinely acquired.

94. Complications