chronic limb ischemia

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LIMB ISCHEMIA

• WANDWI -2021/22/23- HKMU

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LOWER LIMB ISCHEMIA

• DEFINITION
• PATHOPHYSIOLOGY
• CAUSES
• PRESENTATION
• DIAGNOSIS
• TREATMENT
• COMPLICATIONS

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What is limb ischemia?

• Def. Also known as occlusive arterial disease of
  lower extremity
• peripheral arterial disease peripheral
  vascular disease
• Present in ACUTE and CHRONIC form

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LOWER LIMB ISCHEMIA - PATHOPHYSIOLOGY

• PLAQUE FORMATION
• Endothelial injury ? ?lipids permeability ? build
  in intima ?macrophages penetrate vascular wall
  layers -induces smooth muscle cells to migrate
  from the media into the intima plaque formation

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LOWER LIMB ISCHEMIA - PATHOPHYSIOLOGY

• ?Vessel occlusion ? arterial narrowing ?
  Decreased blood flow PAIN
• Pain results from an imbalance between supply and
  demand of blood flow that fails to satisfy
  ongoing metabolic requirements
• Ref. doi 10.1007/s00772-018-0380-1

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LOWER LIMB ISCHEMIA - pathophysiology
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LOWER LIMB ISCHEMIA - causes

• A. ATHEROSCLEROSIS (AS)primary cause
• Inflammatory condition of elastic and muscular
  arteries,
• Segmental involvement.
• Involved commonly infrarenal part of AA,
  iliofemoral vessels, carotid bifurcation,
  popliteal, renal and mesenteric arteries

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LOWER LIMB ISCHEMIA AS types
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LOWER LIMB ISCHEMIA - TAO

• B. THROMBO ANGIITIS OBLITERANS(TAO)
• Small and medium-sized vessels,
• Nonatherosclerotic inflammatory occlusive, a
  disease with superficial thrombophlebitis
• Segmental,
• Progressive

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LOWER LIMB ISCHEMIA - TAO

• B. THROMBO ANGIITIS OBLITERANS(TAO)
• Present with micro-abscesses, neutrophil and
  giant cell infiltration, with skip lesions
• Smoker young males
• Smoking Causes vasospasm and hyperplasia of the
  intima
• lower limb, single or bilateral

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LOWER LIMB ISCHEMIA - TAO
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LOWER LIMB ISCHEMIA - causes

• C. TAKAYASUS PULSELESS ARTERITIS
• Initially symptomless panarteritis involves all
  layers of arteries
• Common in young females/Japan
• often bilateral
• D. RAYNAUDS DISEASE
• upper limb (hand) arteriolar spasm d/t abnormal
  sensitivity to cold
• Gangrene if spasm persists
• Females, usually bilateral
• blanching, cyanosis and later flushing as in
  Raynauds syndrome

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LOWER LIMB ISCHEMIA - causes

• Collagen vascular Disease
• Embolism
• Vascular trauma
• Aneurysm

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LOWER LIMB ISCHEMIA - PRESENTATION

• PAIN claudication..
• ULCERATION - ulcer
• GANGRENE

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LOWER LIMB ISCHEMIA - PRESENTATION

• Pain on walking
• Intermittent claudication / Rest pain
• Paranesthesia
• Pallor
• Diminished or absent pulse

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LOWER LIMB ISCHEMIA - PRESENTATION

• Cold limb ( Poikilothermia)
• Diminished hair , brittle nail , thinning
  shining of skin
• Small Ulcer
• Gangrene

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LOWER LIMB ISCHEMIA DIAG-HX

• Age AS vs TAO
• Sex.
• Limb(s) affected
• Onset acute/chronic
• Pain site, character, radiation,
  aggravating/relieving- (walking vs rest) or
  present at rest pain.
• Importance
• Social Hx/ Family Hx
• Dibetes

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LOWER LIMB ISCHEMIA DIAG-HX
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LOWER LIMB ISCHEMIA DIAG-HX
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LOWER LIMB ISCHEMIA DIAG-PE
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LOWER LIMB ISCHEMIA DIAG-PE
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LOWER LIMB ISCHEMIA DIAG-PE
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LOWER LIMB ISCHEMIA DIAG-INV

• FBP, HOMOCYSTEINE
• Coags.
• Lipids
• HBA1c
• Duplex Ultrasound

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LOWER LIMB ISCHEMIA DIAG-INV

• IMAGING-WHEN
• TO IMAGE TO INTERVENE
• Pts with disabling symptoms where
  revascularization is considered
• To accurately depict the anatomy of stenosis and
  plan for PCI or Surgery
• Sometimes in pts with discrepancies in hx and
  clinical findings

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LOWER LIMB ISCHEMIA DIAG-INV

• ANGIOGRAPHY
• Noninvasive
• CT Angiogram
• MR Angiogram
• Invasive
• Digital Subtraction Angiography - Gold Standard
• Intervention at the same time

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Treatment overview

• Two treatment principles underlying under the
  adage of primum non nocere (first do no harm)
• 1 Treat handicap, not disability
• tailored to the patient i.e If a patient
  claudicates at 500 m (the disability) but seldom
  needs to walk that distance, there is no
  handicap with this disability and therefore the
  patient needs no treatment.

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Treatment overview

• However, if the patient is young and work
  requires him or her to walk 500 m (e.g. on a post
  round) then the patient is handicapped by the
  disability and merits treatment.
• There are usually two treatment options
  conservative management and surgery.
  Reconstructive surgery can produce dramatic
  results but at a risk.

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Treatment overview

• Two treatment principles underlying -adage of
  primum non nocere (first do no harm)
• 2. Prophylactic surgery is appropriate only when
  the risk of the event outweighs the risk of the
  procedure.
• For example, surgical repair of an aortic
  aneurysm is advised when the risk of rupture
  (which is usu ally fatal) outweighs the operative
  mortality.
• If the patient is a poor operative risk then the
  threshold for surgery increases

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Treatment

• 1. RISK FACTOR MODIFICATION
• Smoking Cessation
• Rigorous BSL control
• BP reduction
• Lipid Lowering Therapy

• 2. EXERCISE
• Claudication exercise rehabilitation program
• 45-60mins 3x weekly for 12 weeks
• 6 months later 6.5mins walking time (before pain)

• 3. MEDICAL MANAGEMENT
• Antiplatelet therapy e.g. Aspirin/Clopidogrel
• Phosphodiesterase Inhibitor e.g. Cilostazol
• Foot Care

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PA/Surgery

• Indications/Considerations
• Poor response to exercise rehabilitation
  pharmacologic therapy.
• Significantly disabled by claudication, poor QOL
• The patient is able to benefit from an
  improvement in claudication
• The individuals anticipated natural hx and
  prognosis
• Morphology of the lesion (low risk high
  probability of operation success)

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PA/Surgery

• PCI
• Angioplasty and Stenting
• Should be offered first to patients with
  significant comorbidities who are not expected to
  live more than 1-2 years

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PA/Surgery

• Bypass Surgery
• Reverse the saphenous vein for femoropopliteal
  bypass
• Synthetic prosthesis for aortoiliac or
  iliofemoral bypass
• Others iliac endarterectomy thrombolysis
• Current Cochrane review not enough evidence for
  BypassgtPCI
• Amputation Last Resort

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ACUTE LIMB ISCHEMIA

• Sudden occlusion of a major peripheral artery
• Etiology
• (A) Arterial embolus,
• i) cardio arterial embolization atrial or
  r-l emboli
• ii) intraarterial embolization- from ulcerated
  atherosclerotic plaque. any part of the artery
• (B) Trauma-penetrating wounds, Pressure on a
  major artery by an angulated bone spicule
• (C) Acute arterial thrombosis-lower end of the
  femoral narrowest -acute on chronic

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What are the features of an acute ischemic limb?

• REMEMBER THE 6 PS
• PAIN
• PALLOR
• PULSELESNESS
• PERISHING COLD (POIKILOTHERMIA)
• PARASTHESIAS
• PARALYSIS

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HISTORY EXAM FINDINGS

• Hx
• Smokes 20cigs/day for 30 years
• 4 months of leg cramps in BOTH legs
• 2-3 weeks of intermittent chest palpitations

• Examination
• Inspection
• LLL below the knee is pale/cool
• Palpation
• Irregularly irregular pulse
• LLL Capillary return is sluggish
• No pulses palpable below L femoral artery
• All pulses palpable but appear reduced in R leg
• Normal Sensation Movement bilaterally

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Acute limb ischemia?

• Simple measures to improve existing perfusion
• Keep the foot dependant
• Avoid pressure over the heel
• Avoid extremes of temperature (cold induces
  vasospasm)
• Maximum tissue oxygenation (oxygen inhalation)
• Correct hypotension

• 2. INVESTIGATIONS
• FBc
• Doppler USS
• Coagulation Studies
• Group and Hold
• 12 Lead ECG
• Chest XR

• 3. INITATE ACUTE MANAGEMENT
• Analgesia
• Commence IV heparin
• Call Radiology for Angiography if limb still
  viable
• Discuss with registrar
• Thrombotic cause ? ?cathetar induced thrombolysis
• Embolic cause ? ?embolectomy
• All other measures not possible ?
  Bypass/Amputation

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Upper limb ischemia

• UPPER LIMB ISCHEMIA
• Aorto-arteritis (Takayasu arteritis )
• Raynaud's disease
• Thoracic outlet obstruction
• Other rarer causes,
• nodular periarteritis,
• dermatomyositis,
• systemic scleroderma

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Upper limb ischemia

• THORACIC OUTLET SYNDROME
• Causes of thoracic outlet syndrome
• Cervical rib
• Long C7 transverse process
• Anomalous insertion of scalene muscles
• Scalene muscle hypertrophy

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Upper limb ischemia

• THORACIC OUTLET SYNDROME
• Scalene minimus
• Abnormal bands and ligaments
• Fracture clavicle or first rib
• Exostosis
• Tumours in the region

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Upper limb ischemia

• Diagnosis hx and PE
• Investigations
• Treatment specific