Cerebrovascular Disease by yurtgc548

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									           Cerebrovascular Disease




  Murray Shames, M.D.
Assistant Professor of Surgery and Radiology

           Division of Vascular and
            Endovascular Surgery
        Cerebrovascular Disease
Fundamentals:
   Stroke is the third leading
  cause of death in the USA
  (200 000)
   Incidence 160/100 000
   HTN most common cause
   30% associated with
  extracranial carotid stenosis
   Significant disability   $7.5 billion (1976)
       Cerebrovascular Disease
Relative Risk for Ischemia:

        Age:
              10/100,000 < 45 yr
              1000/100,000 > 75 yr
        Hypertension: 6x
        Atrial fibrillation: 6x
        Prior stroke/TIA: 5 x
        Asymptomatic carotid bruit: 3x
        Smoking: 2x
        Cerebrovascular Disease

Pathology:        Carotid Artery Lesion




90 % atherosclerosis


                                 10% fibromuscular
                             dysplasia, intimal dissection,
                                inflammatory lesions,
                                       radiation
          Cerebrovascular Disease

 Atherosclerosis:

 Similar L-R distribution

 40% of lesions at proximal ICA

 20% of lesions at proximal vertebral

 Aortic arch disease in 10% of
patients
    Cerebrovascular Disease

Other causes of stroke:
      Cardiac embolus
          atrial fibrillation
          heart valve disease
        Rupture of intracranial aneurysm
        Intra-cranial hemorrhage
        Carotid artery dissection
        Carotid aneurysm
      Fibromuscular dysplasia
      Radiation
        Cerebrovascular Disease
Fibromuscular Dysplasia:
   Carotid second most common site of disease
   92% Women
   30% of patients intracranial aneurysms
   Degenerative process involving long, unbranched
         medium sized vessels
   Hormonal, mechanical, unusual distribution of vasa
         vasorum
   Histology
        Intimal fibroplasia
        Medial Hyperplasia
        Medial Fibroplasia (most common)- replacement of
        media with dense fibrous connective tissue
        Perimedial dysplasia (renals)
       Cerebrovascular Disease
Carotid Dissection:

 Traumatic
disruption of
intima
 Compression
of true lumen
          Cerebrovascular Disease

 Pathogenesis of Atherosclerosis:

 Intimal injury (hemodynamics)
 Nodular deposition of fat in arterial intima
 Associated inflammatory response – fibroblast,
       smooth muscle cell proliferation
 Slow accumulation of lipoproteins
 Calcium precipitation in the primary fatty plaque.
       Cerebrovascular Disease

Hemodynamics:

  High shear stress
  Turbulent flow
  Flow seperation
  Propensity for outer wall
   opposite flow divider
          Cerebrovascular Disease

Atherosclerosis:


 Flow reducing
 Embolic
    Clot
    Platelets
    Cholesterol debris
 Thrombosis
      Cerebrovascular Disease

Complex Carotid Plaques:

      Calcification
      Loss of intimal
       continuity
      Ulcer formation
      Subintimal necrosis
      Plaque hemorrhage
        Cerebrovascular Disease

Presentation:

  Asymptomatic
  Transient Ischemic Attacks
  Cerebral Infarction
        Cerebrovascular Disease

 Asymptomatic:
 Natural history-
progression of
disease
 >80% stenosis
associated with
35% risk of
symptoms or
occlusion in 6
months
          Cerebrovascular Disease

      Surveillance:

Duplex scan q 6-
12 months
          Cerebrovascular Disease

Transient Ischemic Attacks:


  reversible,
 painless
 neurologic
 deficit, lasting
 1-5 minutes
  Complete
 recovery < 24 h
         Cerebrovascular Disease
Transient Ischemic Attacks:
      a harbinger of stroke (30-40% of patients with
       surgically accessible carotid stenosis)
      No loss of consciousness - syncope
      Amaurosis fugax: embolus to ipsilateral retinal
       artery
      Aphasia
      Contralateral paralysis, paresis, paresthesias
      Stroke rate at 1 ,3 , 5 years 23%, 27%, 45%
      Crescendo TIA’s/ Stroke in evolution
     Cerebrovascular Disease

Stroke:

   Brain infarction
   50% preceded by TIA
   Embolic or thrombosis with inadequate collaterals
   Symptoms greater than 24 hours
   1/3 resolve, 1/3 deteriorate, 1/3 remain the same
       Cerebrovascular Disease
Sequalae of Internal Carotid Artery Occlusion:

                          propagation of thrombus to
                         intracranial arteries
                          embolization of thrombus
                         both can result in cerebral
                         infarction
                         outcome depends on
                         adequacy of collateral flow:

                         Circle of Willis
       Cerebrovascular Disease
  ‘VIRULENCE’ OF CAROTID ARTERY DISEASE
       BASED ON CLINICAL SYMPTOMS


Clinical entity               Risk of subsequent stroke

Recent (< 4 mo) stroke                 High (10-15%)
Recent hemispheric TIA                 unstable plaque
Recent amaurosis fugax
Previous stroke, TIA, amaurosis
Silent infarct CT or MRI
Asymptomatic bruit                     Low (1-3%)
Non-hemispheric symptoms
Hypertension
      Cerebrovascular Disease

Clinical Evaluation:
     History and Physical Exam
          Degree, duration of symptoms
          Extent of recovery
          Presence of infarction on CT/MRI
     Cerebrovascular Imaging
          Duplex
          Angiography
          MRA
     Cerebrovascular Disease

Velocity Criteria: PSV, ICA/CCA Ratio:

      >50 % stenosis: PSV > 125 cm/sec
       ICA/CCA ratio>2.0
      >60% stenosis: PSV > 230-270 cm/sec
       ICA/CCA ratio>3.5
      >70 % stenosis: PSV > 290-325 cm/sec
       ICA:CCA ratio>4.0
      >80 % stenosis: EDV > 140 cm/sec
       Cerebrovascular Disease

                             The Doppler
                              Principle
                         f
             f
                                               skin
             o
                     
                                   Velocity
                 v                 Profile


                               Sample Volume

Doppler Measurement of Blood Flow Velocity:
      Cerebrovascular Disease

Duplex Ultrasound:
        Cerebrovascular Disease
Criteria of carotid stenosis:
ICA STENOSIS      DUPLEX SCAN                      MRA

    <50% DR        PSV < 125 cm/s                < 50% DR
                   ICA/CCA ratio < 2

   50-74% DR          PSV > 125 cm/s            50-74% DR
                      EDV < 125 cm/s
                   2 < ICA/CCA ratio < 4


   75-99% DR        PSV > 300 cm/s              75-99% DR
                    EDV > 125 cm/s             short (<3 cm)
                   ICA/CCA ratio > 4             flow gap

                     No ICA flow            Long (>3 cm) flow gap
   Occlusion         CCA EDV = 0           No intracranial ICA signal
       Cerebrovascular Disease

Contrast Angiography:




                        High grade ICA stenosis
    Cerebrovascular Disease
High Resolution B-mode Imaging:




  proximal
    Cerebrovascular Disease
Magnetic Resonance Angiography:
     Cerebrovascular Disease

Magnetic Resonance Angiography:
       Cerebrovascular Disease



The ultimate goal of vascular testing is to
identify clinically significant carotid disease,
so that treatment can be applied and risk of
stroke reduced.
        Cerebrovascular Disease

Benefit of CEA for Asymptomatic Stenosis:

                       Annual stroke risk
                       Medical tx   CEA      p value

  VA 1993 (n=444)        2.4 %      1.2 %     > 0.05

  ACAS 1995 (n=1662)     2.2 %       1.0 %     0.004
       Cerebrovascular Disease

Benefit of CEA for Symptomatic Stenosis:
                        Annual stroke risk
                        Medical tx   CEA     p value
  NASCET 1991
   > 70 % stenosis         13 %      4.5 %   < 0.001


  NASCET 1998
   50 - 70 % stenosis      4.4 %     3.1 %    0.045
        Cerebrovascular Disease

Results of surgery vs. medical therapy:
                                       Absolute Reduction
     Symptomatic patients               in Stroke Risk
       NASCET: > 70% DR                 17% @ 2 yr
       NASCET: 50-59%                    10% @ 5 yr
       ECST: > 70% DR                   12% @ 3 yr

        Asymptomatic patients
        ACAS: > 60% DR                   6.3% @ 5 yr



  * multicenter, random assignment - angiography controlled
             Cerebrovascular Disease
                     Cerebrovascular Symptoms
            Carotid Territory TIA              Stroke

                                        ECG, CT Scan, MRI/MRA
       Carotid Duplex Testing   (-)      Cerebral Angiography


      >60% ICA Stenosis
                                       Isolated          Combined Carotid
                                      Bifurcation       Vertebral–Subclavian
                                        Disease               Disease
     Consider for
                                        ASSESS
Carotid Endarterectomy              OPERATIVE RISK


                                      Low           High

                                                          Transluminal
                                                         Angioplasty/Stent
  Cerebrovascular Disease
            Asymptomatic – Carotid Bruit
    <60-70% Stenosis                          >70-80% Stenosis

                                     ? Disease Progression
 Medical Treatment                ?Contralateral ICA Occlusion
                                     Assess life expectancy
- Control of ASO risk factors        Assess Operative Risk
- Aspirin or Clopidogrel
- Surveillance                                       High Risk
                                Good Candidate

                                 Isolated
                                Bifurcation            Medical Rx,
                                  Disease              Carotid stent


                            Carotid
                         Endarterectomy
     Cerebrovascular Disease

Carotid Endarterectomy:

     Considerations:
        Anesthesia
             General
             Regional
        Shunt
        Patch
     Cerebrovascular Disease

Carotid Endarterectomy:
      Cerebrovascular Disease

Carotid Endarterectomy:
       Cerebrovascular Disease

Carotid Endarterectomy:
Cerebrovascular Disease
      Cerebrovascular Disease

Results of Carotid Endarterectomy:
    Clinical              Death/     % of CEAs
    Series      # CEAs    Stroke      w/o Angio

    USF          350     0.6%/0.9%      68%

    Samson       603     0.2%/1.6%      93%

    Melissano    728     0.4%/1.6%      86%

    Logason      229     1.2%/2.2%      80%

    Ascher       903     0.7%/0.7%      94%
     Cerebrovascular Disease


Complications:

     Cranial nerve injury up to 4-16%
     Stroke 1-6%
     Hemorrhage/ hematoma 1-5%
     Mortality < 1%
     Restenosis < 5% (myointimal hyperplasia)
    Cerebrovascular Disease

Carotid Artery Stenting
     Cerebrovascular Disease
    Outcome of Carotid Stent-Assisted
Angioplasty versus Open Surgical Repair for
        Recurrent Carotid Stenosis
               Andrew N. Bowser, MD
               Dennis F. Bandyk, MD
                 Avery Evans, MD
               Michael Novotney, MD
                Martin R. Back, MD
                Brad L. Johnson, MD
               Murray L. Shames, MD

            Division of Vascular & Endovascular Surgery
           University of South Florida College of Medicine
                            Tampa, Florida
       Cerebrovascular Disease
     10-year Concurrent Review (1993-2002)
      • CAS(1997-2002): 50 patients (52 arteries)
      • Redo-CEA: 27 patients
               Re-do CEA                CAS
       Age:        66.5 ± 11           70.2 ± 8     p<0.01
       Men:        19 (70%)            35 (70%)
Co-morbid Conditions:
      HTN          24 (88%)            44 (88%)     p NS
      CAD          13 (48%)            31 (62%)     p NS
      Smoker       19 (70%)            33 (66%)     p NS
       Lipids     16 (59%)            35 (70%)     p NS
      PVD          12 (24%)            24 (48%)     p NS
      DM             8 (30%)            8 (16%)     p = .11
       Cerebrovascular Disease
                      Re-do CEA                 CAS
Number:                  27                     52
Indication:
             Nine CAS patients enrolled in Clinical Trials
    -Symptomatic         17 (63%)            31 (60%)      p NS
                           4 (15%)
         TIA Cordis – Feasibility trial       1 (37%)
                                             19pt.
         CVA             10 (37%)             7 (13%)      p = .02
         Both Archer-1(no distal protection)
                           3 (11%)            2 pts
                                              5 (10%)
              Archer-2 10 protection)
    -Asymptomatic (distal(37%)                3 (40%)
                                             21 pts        p NS
             Crest–Lead-in (distal protection) 3 pts
Mean Interval
to re-intervention:      83 ± 14 mo.          50 ± 8 mo.   p < 0.01

Early (<36m) RCS: 10 (37%)                    33 (63%)     p = 0.03
     Cerebrovascular Disease

 17 CAS pts not surgical candidates: 33%
   - Surgically-inaccessible high lesions (n=8)
   - Severe disabling medical comorbidity (n=4)
   - Neck irradiation (n=3) Soft
                             thrombus
   - Other (RCS with CN injury) (n=2)
 Option of redo-CEA or CAS (n=35)
 3 Redo-CEA Pts Deemed Not CAS Candidates
     Cerebrovascular Disease
      30-Day Procedural Outcomes
                           Ipsilateral    CN        Hematoma/
            Mortality
                          Stroke/TIA     Deficit      Access

Redo CEA                    4%             4%#         4%
               0%
 (n = 27)                 (minor-1)       (n=1)       (n=1)

                           8%**
  CAS         2%*                                      4%
                          major-1,         NA
 (n = 52)     (n=1)                                   (n=2)
                        minor-1,TIA-2
                 #   Transient tongue deviation
  * Pt treated for combined RCS & MCA stenoses – ICH (day-2)
              ** all > 24 hrs after CAS procedure
    Cerebrovascular Disease
       1.0




         Category
Stenosis .8                  < 50%      50-74%   > 75%
                                                      Redo-CEA
                                                            100%

USF - Re-do CEA
         .6
                                                      CAS
                                 82%     11%     7%         0%
(n=27) - 38 mo FU
        .4   p = .25, log rank
   USF - CAS
                                 84%    10%*     6%         0%
(n=51) - 24 mo FU
        .2




       0.0
      * Developed TIA-1; 18
         0    6    12    Regression to <50%-1
                              24    30    36                 42


                                       Months
          Cerebrovascular Disease
             1.00
                                                          Redo-CEA

                                                                 Redo-CEA        Redo
              .80
                                        CAS
                                            Symptomatic
            Asymptomatic                                        Intervention   PTA/CAS

Redo CEA                                                                             7%
              .60   100%                       0%                    0%
 (n=27)                                                                             (n=2)

              .40       p = .82, log rank
  CAS                                        2%                                      8%
                    98%                                         0%
 (n=51)                                     (n=1)                                   (n=4)
                                    No patient developed ipsilateral stroke
              .20
                                    Same patient survival @ 36 mo: 92%
             0.00
                    0         6        12     18     24       30     36   42   48


                                                   Months
    Cerebrovascular Disease
Summary
 Recurrent carotid stenosis can be managed by
  operative or endovascular techniques with
  comparable periprocedural complications, and late
  anatomic & neurologic outcomes.

 The majority of RCS lesions can be treated either
  CAS or redo-CEA – but CAS allowed the treatment
  of lesions not amenable to “open” surgical
  repair/bypass in 1/3rd of patients.

 Duplex follow-up after both redo-CEA and CAS is
  recommended to identify progressive restenosis and
  verify equivalent durability of stented carotid
  segments
          Cerebrovascular Disease
                  SAPPHIRE Trial
•   Randomized, prospective study CAS (Cordis Precise stent, AngioGuard
    filter) v. CEA
•   Symptomatic > 50 % stenosis, asymptomatic > 80 %
•   307 ‘high risk’ patients - class III/IV CHF, open cardiac sx < 6 wks,
    recent MI (< 1mo), unstable angina, need for combined CABG/carotid tx,
    FEV < 1.0, contralat ICA occl, VC paralysis, neck XRT, recurrent
    stenosis, high ICA lesion, prox CCA lesion, tandem stenoses, > 80 yo
•   Results:
    30-day stroke, death, MI rate        CAS 5.8 % v. CEA 12.6 %
    (Excluding MI                        CAS 5.5 % v. CEA 8.4% )
    Symptomatic                          CAS 4.2 % v. CEA 15.4 %
    Asymptomatic                         CAS 6.7 % v. CEA 11.2 %
    Excluding non-neurologic deaths CAS 4.8 % v. CEA 25%
         Cerebrovascular Disease
CEA in HIGH RISK (SAPPHIRE-eligible) Patients
• Retrospective comparison consecutive CEA done in high
  (n=323) and low (n=453) risk pts, 4-yr span Mayo Clinic
• High risk group – positive stress test (14%), age > 80y (11%), contralat
  ICA occl (9%), bad COPD (7%), high lesion (5%), recurrent stenosis
  (3%)
                          High risk          Low risk         P value
       Stroke              1.9 %               1.1 %          no diff
       Death                0.6 %               0%            no diff
       MI                   3.1 %               0.9 %          < .05

Stroke/Death/MI symptomatic 9.3 %              1.6 %           < .005
                asymptomatic 3.4 %             2.1 %           no diff
        Cerebrovascular Disease
               ARCHeR Trial
• Prospective, single arm study CAS (Guidant Acculink
  stent, Accunet filter)
• Symptomatic > 50 % stenosis, asymptomatic > 80 %
• 437 ‘high risk’ pts - multivessel CAD (28%), MI < 1mo, need open
   heart sx, unstable angina, EF<30%/class III/IV CHF (29%), FEV<30%
   predicted, ESRD, bad DM, contralat ICA occl (15%), recurrent stenosis
   (32%), radical neck/XRT, high/low lesions, trach, fixed C-spine, VC
   paralysis, organ transplant
• Successful filter use 92%
• 30-day stroke (minor 3.7%, major 1.4%), death               6.6 %
                 recurrent stenosis subset                     0.7 %
   30-day stroke, death, MI                                   7.8 %
                 contralateral ICA occlusion                   7.6 %
                 ESRD                                          29 %
       Cerebrovascular Disease
                       CARESS Trial

• Observational Registry, CAS (Boston Scientific
  Wallstent, Medtronic GuardWire) v. CEA
• Symptomatic > 50 % stenosis, asymptomatic > 75 % (70%)
• Patient selection based on ‘broad clinical practice’ (not high risk)
• 2:1 CEA (n=254) to CAS (n=143) enrollment


• 30-day stroke, all-cause mortality
             CAS 2.1%       v.    CEA 2.4 %
• 30-day stroke, death, MI
             CAS 2.1 % v.         CEA 3.1 %
           Cerebrovascular Disease

Other Trials:
•SECuRITY – High Risk Registry (Abbott), Procedural success at 30d 94.6%
•MAVeRIC – (Medtronic)30d adverse event 5.2%
•BEACH – High risk trial (Boston Scintific) 30d event rate 5.4%
•CABERNET – (Boston Scientific) 3.4% 30d stroke rate



• Downward Trend in the incidence of adverse
events in recent trials
          Cerebrovascular Disease
       OUTCOME DETERMINANTS FOR CAS :
           UNANSWERED QUESTIONS
• Neuro-protection devices - separating the early CAS ‘learning curve’ from
   more recent use of cerebral protection
                                        with (more recent) without (older)
         Wholey et al (n=10,693)                      2.3 %                 5.3 %
         Roubin et al (n=1276)                        1.8 %                 6.9 %
         German registry (n=1353)                     2.0 %                 2.8 %
• Patient age
   Stroke/death 12 % for > 80 yo, < 5 % for younger (CREST lead-in)
         More complex anatomy > 80 yo  greater CAS risk ?
• Plaque morphology / ‘stability’
   Symptomatic (lipid-rich / soft) v. Asymptomatic (fibrous / calcific plaque)
        Duplex detection of optimal lesions for CAS
• CAS in asymptomatic patients
   CAS or CEA better than medical tx for high-risk, asymptomatic pts ?
   Separating high medical risk from high anatomic risk
         Need for ACAS-equivalent trial (CAS v. medical tx)
     Cerebrovascular Disease
Summary:
 Risk of stroke from extra-cranial carotid
  atherosclerosis related to stenosis severity.

 Patients with carotid territory TIAs or minor stroke; &
  >60% ICA stenosis benefit from surgical intervention.

 High-grade ICA stenosis (>70%) increases the risk of
  stroke in asymptomatic patients.
Cerebrovascular Disease

								
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