Transcript Peripheral Vascular Disease Acute & Chronic Limb Ischemia

Peripheral Vascular
Disease
Acute & Chronic Limb Ischemia
Lipi Shukla
What is PVD?
Definition:
• Also known as PAD or PAOD.
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Occlusive disease of the arteries of
the lower extremity.
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Most common cause:
o Atherothrombosis
o Others: arteritis, aneurysm +
embolism.
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Has both ACUTE and CHRONIC Px
Pathophysiology:
• Arterial narrowing  Decreased
blood flow = Pain
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Pain results from an imbalance
between supply and demand of
blood flow that fails to satisfy
ongoing metabolic requirements.
The Facts:
1. The prevalence: >55 years is 10%–25%
2. 70%–80% of affected individuals are asymptomatic
3. Pt’s with PVD alone have the same relative risk of death from
cardiovascular causes as those CAD or CVD
1. PVD pt’s = 4X more likely to die within 10 years than pt’s without
the disease.
2. The ankle–brachial pressure index (ABPI) is a simple, non-invasive
bedside tool for diagnosing PAD — an ABPI <0.9 = diagnostic for PAD
1. Patients with PAD require medical management to prevent future
coronary and cerebral vascular events.
1. Prognosis at 1 yr in patient’s with Critical Limb Ischemia (rest pain):
• Alive with two limbs — 50%
• Amputation — 25%
• Cardiovascular mortality 25%
Risk Factors:
Typical Patient:
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Smoker (2.5-3x)
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Diabetic (3-4x)
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Hypertension
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Hx of Hypercholesterolemia/AF/IHD/CVA
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Age ≥ 70 years.
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Age 50 - 69 years with a history of smoking or diabetes.
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Age 40 - 49 with diabetes and at least one other risk factor for
atherosclerosis.
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Leg symptoms suggestive of claudication with exertion or
ischemic pain at rest.
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Abnormal lower extremity pulse examination.
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Known atherosclerosis at other sites (eg, coronary, carotid, or
renal artery disease).
Chronic PVD History:
1. INTERMITTENT CLAUDICATION
• Derived from the Latin word ‘to limp’
• “Reproducible pain on exercise which is relieved by rest”
• Pain can also be reproduced by elevating the leg
• “my legs get sore at night and feel better when I hang them over
the edge of the bed”
2. Other Symptom/Signs:
• A burning or aching pain in the feet (especially at night)
• Cold skin/feet
• Increased occurrence of infection
• Non-healing Ulcers
• Asymptomatic
3. Critical Stenosis = >60%, impending acute ischemic limb:
- rest pain
- ischemic ulceration
- gangrene
30% Buttock & Hip Claudication
±Impotence – Leriche’s Syndrome
Thigh Claudication
60% Upper 2/3 Calf Claudication
Lower 1/3 Calf Claudication
Foot Claudication
DDx of Leg Pain
1. Vascular
a)
b)
DVT (as for risk factors)
PVD (claudication)
2. Neurospinal
a)
b)
Disc Disease
Spinal Stenosis (Pseudoclaudication)
3. Neuropathic
a)
b)
Diabetes
Chronic EtOH abuse
4. Musculoskeletal
a)
b)
OA (variation with weather + time of day)
Chronic compartment syndrome
Physical Examination:
Examination:
What do to:
Inspection
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Thick Shiny Skin
Hair Loss
Brittle Nails
Colour Changes (pallor)
Ulcers
Muscle Wasting
Palpation
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Temperature (cool, bilateral/unilateral)
Pulses: ?Regular, ?AAA
Capillary Refill
Sensation/Movement
Auscultation
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Femoral Bruits
Ankle Brachial
Index (ABI)
= Systolic BP in ankle
Systolic BP in brachial artery
Buerger’s Test
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Expose the skin
and look for:
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Elevate the leg to 45° - and look for pallor
Place the leg in a dependent position 90°& look
for a red flushed foot before returning to normal
Pallor at <20° = severe PAD.
Pictures:
What does the ABI mean?
ABI
Clinical Correlation
>0.9
Normal Limb
0.5-0.9
Intermittent Claudication
<0.4
Rest Pain
<0.15
Gangrene
CAUTION:
Patient’s with Diabetes + Renal Failure:
They have calcified arterial walls which can falsely elevate their ABI.
Investigations:
BLOOD TESTS:
1. FBE/EUC/Homocysteine Levels
2. Coagulation Studies
3. Fasting Lipids and Fasting Glucose
4. HBA1C
WHEN TO IMAGE:
1. To image = to intervene
2. Pt’s with disabling symptoms where revascularisation is considered
3. To accurately depict anatomy of stenosis and plan for PCI or Surgery
4. Sometimes in pt’s with discrepancy in hx and clinical findings
NON INVASIVE:
Duplex Ultrasound
 normal is triphasic  biphasic  monophasic  absent
ANGIOGRAPHY:
Non-invasive:
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CT Angiogram
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MR Angiogram
Invasive:
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Digital Subtraction Angiography
 Gold Standard
 Intervention at the same time
Tardus et parvus = small amplitude + slow rising pulse
CT Angiography
Digital Subtraction Angiography
Value of angiography
Localizes the obstruction
Visualize the arterial tree & distal
run-off
Can diagnose an embolus:
Sharp cutoff, reversed meniscus or clot
silhouette
Treatment:
1.
RISK FACTOR MODIFICATION:
a) Smoking Cessation
b) Rigorous BSL control
c) BP reduction
d) Lipid Lowering Therapy
2.
EXERCISE:
a) Claudication exercise
rehabilitation program
b) 45-60mins 3x weekly for 12 weeks
c) 6 months later +6.5mins walking
time (before pain)
3.
MEDICAL MANAGEMENT:
a) Antiplatelet therapy e.g.
Aspirin/Clopidogrel
b) Phosphodiesterase Inhibitor e.g.
Cilostazol
c) Foot Care
PCI/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 individual’s anticipated natural hx and prognosis
•Morphology of the lesion (low risk + high probabilty of operation
success)
PCI:
•Angioplasty and Stenting
•Should be offered first to patients with significant comorbidities who are
not expected to live more than 1-2 years
Bypass Surgery:
•Reverse the saphenous vein for femoro-popliteal bypass
•Synthetic prosthesis for aorto-iliac or ilio-femoral bypass
•Others = iliac endarterectomy & thrombolysis
•Current Cochrane review = not enough evidence for Bypass>PCI
Amputation: Last Resort
Some Bypass Options:
Mr. X presents with an acutely
painful leg:
You have had a busy day in the ED and the next
patient to see is:
Mr. X – a 60 yr old gentleman with a very painful leg.
He tells you that he woke up this morning with an
excruciating pain in his left leg and has never felt
this pain before.
MUST RULE OUT ACUTE LIMB ISCHEMIA
? Embolism (AF/Recent Infarct/Anuerysm)
? Thrombosis of native vessel or graft
?Trauma
What are the features of an
acute ischemic limb?
REMEMBER THE 6 P’S:
1. PAIN
1. PALLOR
1. PULSELESNESS
1. PERISHING COLD (POIKILOTHERMIA)
1. PARASTHESIAS
1. PARALYSIS
Fixed
mottling &
cyanosis
History & Exam Findings
Further Hx:
• Smokes 20cigs/day for 30 years
• 4 months of ‘leg cramps’ in BOTH legs
• 2-3 weeks of intermittent chest palpitations
• Has not seen a Dr. in the last month
Examination:
• Inspection:
o LLL: below the knee is pale/cool
• Palpation:
o Irregularly irregular pulse
o LLL Capillary return is sluggish
o No pulses palpable below L femoral artery
o All pulses palpable but appear reduced in R leg
o Normal Sensation + Movement bilaterally
Impression?
60yo male with a L Acute Ischemic limb on the background of heavy
smoking, untreated AF and symptomatic PVD.
What will you do now?
1. CALL THE VASCULAR REGISTRAR
Simple measures to improve
existing perfusion:
2. ORDER INVESTIGATIONS
a) FBE
b) EUC
c) Coagulation Studies
d) Group and Hold
e) 12 Lead ECG
f) Chest XR
• Keep the foot dependant
• Avoid pressure over the heel
• Avoid extremes of temperature
(cold induces vasospasm)
• Maximum tissue oxygenation
(oxygen inhalation)
3. INITATE ACUTE MANAGEMENT:
• Correct hypotension
a) Analgesia
b) Commence IV heparin
c) Call Radiology for Angiography if limb still viable
d) Discuss with registrar:
i) Thrombotic cause  ?cathetar induced thrombolysis
ii) Embolic cause  ?embolectomy
iii) All other measures not possible  Bypass/Amputation
Mr. X’s Complication
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Angiogram is done in radiology
Shows acute thrombosis of L popliteal artery
Cathetar induced urokinase and heparin infusion is started
…. 3-4 hours later
-Severe calf pain in the reperfused limb
-All pulses are present
-Leg is swollen, tense and +++ tender
REPERFUSION INJURY!
-Restored blood flow can lead to unwanted local + systemic effects
1) Washout =
oMetabolic Acidosis
oHyperkalemia
oARF (myoglobinuria)
oNon-cardiac APO
2) Compartment Syndrome =
oMay need fasciotomy
Learning Outcomes
1. Risk factors for PVD
2. Recognise signs and symptoms of chronic ischemia of the lower limbs
3. Differential diagnosis for leg pain
4. Examine a chronic ischemic limb
5. Understand medical/surgical of management of PVD
6. Recognise an acute ischemic limb
7. Know it is important to call the vascular registrar ASAP
8. Know what investigations to order in the ED
9. Be aware of the manifestations of reperfusion injury
Questions?
References:
Uptodate Articles:
- Clinical features, diagnosis & natural history of lower extremity PAD
- Treatment of chronic critical limb ischemia
- Indications for surgery in the patient with lower extremity claudication
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Norgren L, Hiatt WR, Dormandy JA, et al. Inter-Society Consensus for the
Management of Peripheral Arterial Disease (TASC II). J Vasc Surg 2007; 45 Suppl S:S5
McDaniel MD, Cronenwett JL. Basic data related to the natural history of
intermittent claudication. Ann Vasc Surg 1989; 3:273.
Lane DA, Lip GYH. Treatment of hypertension in peripheral arterial disease.
Cochrane Database of Systematic Reviews 2009, Issue 4. Art. No.: CD003075. DOI:
10.1002/14651858.CD003075.pub2
Murabito JM, Evans JC, Nieto K, et al. Prevalence and clinical correlates of
peripheral arterial disease in the Framingham Offspring Study. Am Heart J 2002;
143:961
Peripheral arterial disease: prognostic significance and prevention of
atherothrombotic complicationsPaul E Norman, John W Eikelboom and Graeme J
HankeyMJA 2004; 181 (3): 150-154
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