Peripheral Vascular Disease Peripheral

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Peripheral Vascular Disease Peripheral Powered By Docstoc
					Peripheral Vascular
     Disease
       Fontaine’s Grading
 Asymptomatic

 Claudication

 Rest pain

 Ulceration and gangrene
             Claudication
Claudication: 3 components
 1.discomfort with exertion - usually in
  calves (cramping), but any exercising
  group
 2.relieved by short rest - 2 to 5 minutes,
  and no postural changes necessary
 3.reproducible - “claudication distance”
Arterial claudication causes reproducible muscle
  ischemic pain from inadequate oxygen delivery.
  While mortality, usually from cardiovascular
  causes, approaches a yearly risk of 5%, the
  annual risk of limb loss in those with claudication
  is only 1%. Over half of all patients stabilize or
  improve with conservative management. 20-
  30% of patients with claudication will require an
  operation within 5 years due to disease
  progression.
           Localizing the level

 Inflow,       Outflow, Runoff
   Buttock, thigh and calf claudication : Common
    iliac artery or aortic disease
   Thigh and calf claudication: EIA

   Calf claudication: Superficial femoral artery.

Femoropopliteal system > aortoiliac
            Aortoiliac Disease
 Type 1
 Type 2
 Type 3


   Aortoiliac hypoplasia
             RISK FACTORS
   Older age (> 40 years)
   Male gender
   Smoking
   Diabetes mellitus
   Hyperlipidemia
   Hypertension
   Hyperhomocysteinemia

    When risk factors coexist, the risk
    increases several-fold
                             Am J Cardiol 2001; 87 (suppl): 3D-13D
                             NEJM 2001; 344: 1608-1621
WHAT CAUSES INTERMITTENT
     CLAUDICATION?
   Atherosclerosis in peripheral arteries of legs

During exercise, oxygen demand increases

      Muscles operate anaerobically

    Produce lactic acid and other metabolites
                    Leg pain
   Lactic acid and other metabolites washed away
    on rest
                                  Am J Cardiol 2001; 87 (suppl): 3D-13D
    PRIMARY
    SITES OF
    INVOLVEMEN
    T
 Femoral & Popliteal
   arteries: 80-90%

 Tibial & Peroneal
   arteries: 40-50%

 Aorta & Iliac
Harrison’s Principles of
     arteries: 30%
Int Med
        Critical Diameter




 Adaptive arterial enlargement preserves
luminal caliber until a critical plaque mass
                is reached
    Critical limb ischaemia
               CLI
 Persistently recurring ischemic rest pain
  requiring regular adequate analgesia for
  more than 2 weeks
 OR ulceration\gangrene of the foot or
  toes, with an ankle pressure of <50 mmHg
  or toe pressures of <30 mmHg
                      Rest Pain
   Rest pain is an imbalance where oxygen supply does not
    meet metabolic requirements. This is a harbinger for
    tissue loss, and indicates a need for revascularization.
    The diminished tissue perfusion impairs normal healing
    mechanisms. Medical optimization, especially the
    initiation of beta-bocker therapy is critical in decreasing
    perioperative morbidity and mortality. Aortoiliac
    occlusive disease has been increasingly addressed
   with angioplasty and stents. Studies have shown that
    results are more favorable for common iliac (80%
    patency) than common femoral (50%). The
    percutaneous treatment of long lesions have poorer
    outcomes compared to isolayed short lesions.
           Leriche’s syndrome
   As described, Leriche’s syndrome, has a component of
    intermittent thigh claudication and impotence from
    hypogastric artery occlusion with decreased flow through
    the pudendal artery and the corpora cavernosum. Distal
    pulses are usually diminished or absent, but trophic
    changes are absent due to collaterals. Tissue loss
    implies distal disease, except in the case of shower
    emboli from the occlusive iliac plaque causing a “blue
    toe” syndrome. This population is prone to cardiac
    disease and 10% of patients with AOD will have
    associated aortic aneurysms. Angioplasty works to
    alleviate isolated lesions and in concert with distal
    surgery to improve inflow prior to surgical
    revascularization
        Buerger’s Disease:
 Small and medium arteries and veins
 Obliterative thrombo-angitis (thrombus
  filled with inflammatory cells
 Etiology: unknown
 Heavy cigarette smoking
 Males are almost exclusively affected
 Typically palpable femoral and popliteal
  pulses but absent distal pulses.
                     DIAGNOSIS
   History taking
   Careful examination of leg
   Pulse evaluation
   Ankle-brachial index (ABI):
      SBP in ankle (dorsalis pedis and posterior tibial arteries)
    ___________________________________
      SBP in upper arm (brachial artery)




                                     Am J Cardiol 2001; 87 (suppl): 3D-13D
                                     NEJM 2001; 344: 1608-1621
                  ABPI
   Intermittent claudication

   Rest Pain

   Tissue gangrene

                 Four cuff technique
                  Treadmill protocol
               Toe pressures

   Provides accurate assessment of distal
    circulation
   Not influenced by calcification in pedal vessels
   Calcification particularly seen in diabetics
   Normal toe pressures are 90-100 mmHg
   Toe pressure less than 30 mmHg suggests
    critical limb ischaemia
                      MRA
To plan intervention in patients where
 angiography is contraindicated :

      Renalfailure, contrast rxn, poor angiograghic
      access, iliac occlusive disease.
WHY IS IT NECESSARY TO TREAT
INTERMITTENT CLAUDICATION ?
  Symptoms worsen in 25% of
   patients
  Approximately 5% will require
   amputation within 5 years
  Around 5-10% have critical limb
   ischemia; risk of limb loss
  Increased risk of mortality, primarily
   for cardiovascular causes
          MANAGEMENT
 Risk factor modification
 Exercise therapy
 Antiplatelet therapy
 Medical therapy targeted at symptoms
 Revascularisation procedures
MODIFICATION OF RISK FACTORS

   Smoking cessation
   Diabetes control (FBG 80-120 mg/dl, PPG <
    180 mg/dl, HbA1c < 7%)
   Dyslipidemia management (LDL < 100 mg/dl,
    TG < 150 mg/dl): Statins (RR 38%; 4S)
   Hypertension control (BP < 130/85 mmHg)
   Ramipril [RR 28%; HOPE (n=4051)]

                           Am J Cardiol 2001; 87 (suppl): 3D-13D
                           NEJM 2001; 344: 1608-21
                           Am J Med 2002; 112: 49-57
      EXERCISE PROGRAM
 Improves walking ability
 Requires motivation and personalised
  supervision
 Benefits lost if not maintained on regular
  basis
 Overall effectiveness limited


                           NEJM 2001; 344: 1608-21
   60-80% get better with conservative
    therapy, 20-30% stay the same, 5-10% get
    worse
 MEDICAL THERAPY USED IN PAST FOR
MANAGING INTERMITTENT CLAUDICATION
            SYMPTOMS

   Vasodilators (e.g. verapamil,
    isoxsuprine, cinnarizine, xanthinol
    nicotinate, cyclandelate)
     Several controlled trials have
     found no evidence of clinical
     efficacy of drugs of this class
    ANTIPLATELET THERAPY
 Aspirin
 Clopidogrel (CAPRIE Study)

    No studies have shown that
    aspirin or clopidogrel improves
    claudication symptoms



                         NEJM 2001; 344: 1608-21
    WHAT IS THE CURRENT
 STATUS ON PENTOXIFYLLINE?
“Pentoxifylline is no longer recommended
for first-line therapy for most patients with
intermittent claudication”

                  1996 AHA Scientific Statement




                           Am J Med 2002; 112: 49-57
PENTOXIFYLLINE NOT RECOMMENDED
 FOR INTERMITTENT CLAUDICATION
   Inconsistent and modest benefit; non-significant
    increase in walking ability
   Not more effective than placebo in increasing walking
    ability or functional status
   Most trials small and not properly designed
   Study sample size and pentoxifylline response inversely
    correlated

“Data are insufficient to support its widespread use”

(Meta-analysis of pentoxifylline trials)
1608-1621

                                     Am J Cardiol 2001; 87 (suppl): 19D-27D

                                 NEJM 2001; 344:
UNIQUE MECHANISM OF ACTION
                      Cilostazol
                                 cAMP



   Platelets          Vascular smooth           Lipoprotein
                          muscle               lipase activity
                                               TG synthesis



    Platelet      Vasodilation                    TG
  aggregation       peripheral blood               HDL
 and activation     flow
                   Antiproliferative effect
CILOSTAZOL EXERTS SIGNIFICANT
    ANTIPLATELET EFFECTS

     Inhibits platelet aggregation induced by
      ADP, collagen, adrenaline, arachidonic
      acid and thrombin
     More potent in suppressing platelet
      aggregation than aspirin or ticlopidine


                           Ann Pharmacother 2001; 35: 48-56
                             Drugs & Aging 1999; 14: 63-71
                          Arzneim Forschung 1987; 37: 563-566
    Indications for intervention in
       intermittent claudication
   Disabling claudication
   Critical limb ischaemia
   Arteriography is essentially a preoperative
    investigation
   Arteriography is not required in the routine
    assessment of claudication
   Two options are:
   Percutaneous angioplasty
   Bypass surgery
               Bypass Surgery
   The gold standard for arterial reconstruction below the
    inguinal ligament, and especially below the knee, is the
    reversed saphenous vein graft, though recent literature
    suggests that in-situ can achieve equal results. Both can
    achieve 5-year patency rates of 75%-80%. Earlier
    bypass translates to higher patency rates because the
    intervention is performed at an earlier point in the
    disease progression. Other things that will decrease
    patency are continued cigarette smoking, small vein
    size, poor distal runoff, or the use of synthetic material
    below the knee. It is important to note that limb salvage
    exceeds graft patency, and in many cases (up to 50%)
    when the healing is complete, limb salvage is maintained
    despite subsequent loss of graft patency.
Percutaneous transluminal angioplasty
 Angioplasty of the aorto-iliac segment has a 90% 5 year
  patency
 Angioplasty of the infra-inguinal vessels has a 70% 5
  year patency
 Best results seen with short segment stenoses less than
  2 cm long
 Complications occur in less than 2% of patients
      Wound haematoma
      Acute thrombosis
      Distal embolisation
      Arterial wall rupture
Bypass surgery
Types of bypass graft include:
 Biological grafts
       Autografts
            Long saphenous vein     - in-situ or reversed
            Internal mammary artery
       Allografts
            Dacron coated umbilical vein
   Synthetic grafts
       Dacron           -woven or knitted        +/- albumin coated
       Woven grafts - smaller pores. No preclotting required
   Velour                   -Polyfluorotetraethylene( PTFE )
Choice of graft material
 Determined by long term patency rates
 Autologous vein is best graft material but not
  always available
 Interposition of vein between PTFE graft and
  artery at distal anastomosis can improve long
  term patency
 Vein often fashioned as either Miller cuff of
  Taylor patch
Reasons for graft failure
 Less than 30 days - technical failure
 30 days to 1 years - neointimal hyperplasia at distal anastomosis
 More than 1 years - progression of distal disease


Bibliography
 Shearman C P. Management of intermittent claudication. Br J Surg
   2002; 89: 529-531.
 Golledge J. Lower limb arterial disease. Lancet 1997; 350: 1459 -
   1465.
 Hiatt W R. Medical treatment of peripheral arterial disease and
   claudication. N Eng J Med 2001; 344: 1608-1621.

				
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