Carotid artery stenting is an alternative to carotid endarterectomy for treating carotid artery stenosis. The document discusses the indications for and procedures involved in carotid revascularization. It summarizes several key studies comparing stenting to endarterectomy. For symptomatic patients, stenting was found to be non-inferior to surgery with the risk of stroke or death below 6%. Recent advances discussed include new embolic protection devices, stent designs like double layer mesh stents, and the transradial approach to reduce manipulation of complex aortic arches. Overall the document provides an overview of carotid stenting procedures and updates on recent technology improvements aimed at reducing risks.

1. Carotid artery stenting- a
clinical update
Dr Siva Subramaniyan
PGIMER &Dr.RML Hospital
New Delhi

2. STROKE
• Stroke is a global health problem.
• It is the second commonest cause of death and fourth leading cause of disability
worldwide .
• Approximately 20 million people each year will suffer from stroke and of these 5
million will not survive .
• In developed countries, stroke is the first leading cause for disability, second
leading cause of dementia and third leading cause of death.
• Stroke is also a predisposing factor for epilepsy, falls and depression in developed
countries and is a leading cause of functional impairments, with 20% of survivors
requiring institutional care after 3 months and 15% - 30% being permanently
disabled.

3. carotid atherosclerosis
• Carotid stenosis is important cause of ischemic strokes, accounting for 20 to 25%.
• Most frequently affected sites - proximal internal carotid artery and carotid
bifurcation.

4. Why do we need carotid revascularization?
•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

5. Why do we need carotid revascularization?
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 = 45-65%
Sacco et al. Stroke, 1982
Meissner et al. Stroke, 1988

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

7. MANAGEMENT
• Medical
• Stenting
• Surgery

8. carotid endarterectomy

9. indication
• Symptomatic Patients
• Asymptomatic Patients

10. SYMPTOMATIC PATIENTS
• There is little controversy regarding the net benefit of carotid endarterectomy in
patients with symptomatic moderate- to high-grade stenosis.
• A key finding was that the benefits are greater for patients with higher degrees of
stenosis.
• A meta-analysis of the 3 major clinical trials analysis revealed that
endarterectomy was marginally beneficial for patients with 50% to 69% stenosis,
with an annual absolute risk reduction of ipsilateral ischemic stroke of 4.6%.
• The procedure was substantially more beneficial for patients with 70% to 99%
stenosis, with an annual absolute risk reduction of ipsilateral ischemic stroke of
16%.

11. • Subgroup analysis revealed the greatest benefits for
- men,
- patients 75 years of age or older, and
- patients randomized within 2 weeks after their last ischemic event.

12. • 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
NASCET (North American Symptomatic Carotid Trial)

13. 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%

14. ASYMPTOMATIC PATIENTS
• Although the effectiveness of timely endarterectomy for symptomatic high-grade
carotid stenosis is well established, the benefits of endarterectomy in patients
with asymptomatic carotid stenosis are less certain.
• Two pivotal randomized trials support endarterectomy for asymptomatic
stenosis: the Asymptomatic Carotid Atherosclerosis Study (ACAS) and the ACST.
• Patients were followed up for an average of 2.7 years and found that surgical
intervention resulted in an absolute reduction in the risk of ipsilateral stroke,
surgical stroke, or death of 5.9%.

16. CAROTID ANGIOPLASTY AND STENTING

17. CAROTID ANGIOPLASTY AND STENTING
• Carotid angioplasty and stenting evolved as a potentially safer alternative to
endarterectomy.
• A series of randomized trials ensued, mostly in patients with symptomatic
stenosis.

18. • Stenting reduces the risk of embolization, thrombosis, carotid artery recoil, and
long-term restenosis.
• Carotid endarterectomy remains the preferred treatment for most patients with
symptomatic carotid atherosclerosis.
• Only applies when the periprocedural risk of stroke and death with CAS for the
operator or center is <6 percent.

19. • Symptomatic Patients
• asymptomatic Patients

35. procedure

36. • Femoral access
• Arch angiography
• Selective catheterization of target CCA
• Wire placement in ECA
• Sheath or GC placement in distal CCA
• Placement of embolic protection device
• Pre-dilation of lesion
• Stent placement
• Post-dilation of stent
• Removal of EPD
• Final angiography
Fundamental Steps

37. perioperative antiplatelet therapy
• Treated with aspirin (325 mg twice daily) and clopidogrel (75 mg twice daily)
starting at least 48 hours before the CAS procedure.
• Those scheduled for CAS within 48 hours - aspirin 650 mg and clopidogrel 450
mg at least four hours before

38. • Following CAS, treatment include aspirin 325 mg once or twice daily and
clopidogrel 75 mg daily (or ticlopidine 250 mg twice daily) for at least 30 days,
with a recommendation to continue aspirin indefinitely.

39. ARCH AORTOGRAM
• 30-40 LAO view
• Field of view should include origin of great vessels and extend to
include the carotid bifurcation
• Patient’s head should be straight with chin turned upward

40. diagnostic arteriogram
arch classification.

41. CAROTID ANGIOGRAPHY
• Ipsilateral oblique and lateral views (additional views may be necessary)
• Contralateral carotid (Circle of Willis, collaterals, etc)

42. INTRACEREBRAL ANGIOGRAPHY
• Anterior cerebral circulation viewed by PA cranial (15-20 degrees) and
lateral views
• Important to visualize both arterial and venous phases:
- Intracerebral disease
- Collateral circulation
- Presence of AVM, aneurysm
- Missing arterial phase vessels
(allows identification of embolization post CAS)

43. • Diagnostic catheter (125 cm) engaged in innominate or LCCA
• Roadmap view (preferably lateral) to visualize bifurcation of ECA and
ICA
• Stiff, angled 0.035 hydrophilic wire advanced into ECA using roadmap
guidance
• Dx catheter advanced over wire into the ECA
• Guide wire exchanged for super stiff (1 or 6 cm soft tip)
• 6F sheath advanced into CCA over guidewire
• Guidewire removed
SHEATH PLACEMENT IN CCA

44. Embolic Protection Device Placement
Three general types of EPD:
• Distal occlusion balloon
• Distal filter device
• Proximal flow diversion

47. PREDILATATION
• Predilatation allows stent delivery systems to be advanced without being
constrained or trapped.
• It then allows deployment, advancement of the stent, and removal of the EPD
through the stent.
• Ideally to use a 4-mm balloon of sufficient length to allow treatment of the entire
lesion.
• Brief and rapid inflation to eliminate indentation and slow deflation may reduce
embolization.

48. STENT SELECTION AND DEPLOYMENT

50. POSTSTENT BALLOON DILATATION
• generally post dilatation may be required in most stenotic portion of the stented
area with a 5- to 6-mm-diameter, short 2-cm balloon.
• Aggressive overdilatation of the carotid lesion may result in the liberation of a
large amount of particulate debris.
• A mild residual stenosis of the target lesion (20%) may be accepted in an effort to
avoid generating excessive embolic debris and avoid potentially severe embolic
complications.

51. • Carotid Angiography:
- evaluate target lesion status
- stent expansion
- distal runoff
- evidence of spasm or dissection
• PA and lateral intracranial views
- exclude evidence of embolization
FINAL ANGIOGRAPHY

56. open vs close stent
• Classifying a stent as either open cell or closed cell is based on the free-cell area
of a given stent.
• Closed-cell stents have a smaller free-cell area between the stent lattices. As a
consequence, closed-cell stents are more rigid, and therefore, less conformable in
tortuous vessels. These characteristics can make advancing a closed-cell stent
more challenging in serpentine vessels.
• the larger free-cell area between the stent struts in an open-cell stent creates a
more malleable structure. Therefore, open-cell stents readily navigate through
tortuous vessels allowing smooth device delivery in unfavourable anatomy

59. RECENT ADVANCES

60. TECHNOLOGY ADVANCEMENTS
• Although the insufficient expertise, both in terms of skills and in patient selection,
may be the main factor leading to stroke excess in CAS compared with CEA, CAS
as it was performed in the randomized trials carried some intrinsic limitations:
(i) distal EPD (filters) may not adequately protect the brain in all settings, due to
incomplete apposition to the vessel wall, lack of protection during placement of the
EPD, and the passage of micro-emboli smaller that the pore size of the filter;
(ii) current stent frames may have insufficient lesion scaffolding properties and
allow for intra-strut plaque prolapse;
(iii) catheter manipulations at the level of the aortic arch may be an important
source of emboli not prevented by current EPD technology.

61. 1) PROXIMAL CEREBRAL PROTECTION
• Proximal EPD protects the brain by interrupting or reversing the blood flow at the
level of the carotid bifurcation at the time of the procedure.
• This approach as emerged as alternative to distal EPD. The main advantages of
proximal protection include crossing of the lesion under protected conditions as
well as the blockage of both macro- and micro-emboli.
• Finally, with proximal protection there is no placement of a device in the distal
internal carotid artery, and this may reduce the risk of arterial spasm, dissection,
or intimal damage

62. • Mo.Ma system
• NeuroProtection System

63. Mo.MaTM (Medtronic-Invatec, Roncadelle, Italy)
• The Mo.Ma system consists of an 8F or 9F sheath with an effective working
channel of a 5F and 6F sheaths, respectively, and two independently inflatable
balloon catheters.

64. NeuroProtection System

65. 2) stent design

66. • One of the study evaluated clinical outcomes according to different carotid stent
designs among 1,604 patients in the european population who underwent
neuroprotected CAS. They noted that conflicting data exist on the impact on the
outcome of the use of different stent types during CAS.
• Open-cell design stents were classified according to free cell area into < 7.5
mm2 or > 7.5 mm2. A total of 713 closed-cell, 456 hybrid-cell, 238 < 7.5
mm2 open-cell, and 197 > 7.5 mm2 open-cell stents were implanted.

67. • Overall, the 30-day stroke and death rate was 1.37%. At 30 days, 19 strokes
occurred (1.18%): eight in the group of patients treated with a closed-cell
(1.12%), two in those with a hybrid-cell (0.44%), three in those with a < 7.5
mm2 open-cell (1.26%), and six in those treated with a > 7.5 mm2 open-cell stent
(3.05%) (P = .045).
• These data suggest that, in the setting of neuroprotected CAS performed in high-
volume centers by properly trained operators, the use of an open-cell design
stent with a free cell area > 7.5 mm2 may be associated with an increased 30-day
stroke risk.

68. Double layer mesh stent technology
• Recently, it has been recognized that the stent itself may substantially add to
embolic protection in CAS through adequate scaffolding of the plaque once the
EPD has been removed.
• The ideal properties of a carotid stent are a well-balanced mix of high flexibility
and conformability, to accommodate tortuous anatomy, as well as high plaque
coverage, to prevent late embolization of debris.

69. • Recently, a novel carotid stent design has been developed, namely the double
layer mesh stent. The design should allow for high flexibility to accommodate
tortuous anatomy and at the same time convey scaffold properties for optimal
plaque coverage.
• This technology is characterized by an internal micromesh layer for plaque
coverage and an external self-expanding nitinol layer for scaffolding offering the
flexibility that characterize open-cell design stents.
• Currently, the only CE marked and commercially available double layer mesh
stent- RoadSaver stent

71. • One study evaluated the dual-layer micromesh Roadsaver carotid stent (Terumo
Europe). The prospective, multinational, single-arm, physician-initiated study is
designed evaluate the Roadsaver in 100 nonconsecutive patients at high risk for
carotid endarterectomy requiring revascularization. Patients were enrolled at
nine centers in Belgium, Italy, and Germany.
• The investigators reported the primary endpoint, which is the 30-day rate of
major adverse events (MAE), defined as the cumulative incidence of any death,
stroke, or myocardial infarction (MI). In the study, the use of embolic protection
devices (EPDs) was not mandatory; 31% of the patients were symptomatic, and in
58% of the patients, EPDs were used. Technical success was achieved in all cases.

72. • The 30-day MAE rate was 2.1% (one patient experienced MI followed by death;
another patient experienced a stroke within the first 30 days after procedure).
Although no statistical analysis could be performed, subgroup data suggested
that there were no notable differences in the 30-day MAE rate between
symptomatic and asymptomatic patients, nor regarding EPD use.
• The CLEAR-ROAD investigators concluded that the Roadsaver carotid stent shows
promising results and that it is a safe and effective device for endovascular
treatment of subjects at high risk for carotid endarterectomy.

73. 3) aortic arch manipulation

74. • The transradial approach may be a valuable alternative to transfemoral access for
CAS in patients with advanced peripheral vascular disease of with complex aortic
arches such as the bovine or the type III arches.
• It can reduce stroke rate by reduced manipulation.

75. THANK YOU