Peripheral Vascular Disease

Acute & Chronic Limb Ischemia

Lipi Shukla

What is PVD?Definition:• Also known as PAD or PAOD.

• Occlusive disease of the arteries of the lower extremity.

• Most common cause:o Atherothrombosiso Others: arteritis, aneurysm +

embolism.

• Has both ACUTE and CHRONIC Px

Pathophysiology:• 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.

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:• Smoker (2.5-3x)• Diabetic (3-4x)• Hypertension• Hx of Hypercholesterolemia/AF/IHD/CVA

• Age ≥ 70 years.

• Age 50 - 69 years with a history of smoking or diabetes.

• Age 40 - 49 with diabetes and at least one other risk factor for atherosclerosis.

• Leg symptoms suggestive of claudication with exertion or ischemic pain at rest.

• Abnormal lower extremity pulse examination.

• Known atherosclerosis at other sites (eg, coronary, carotid, or renal artery disease).

Chronic PVD History:

3. Critical Stenosis = >60%, impending acute ischemic limb:- rest pain- ischemic ulceration- gangrene

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

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”

Thigh Claudication

60% Upper 2/3 Calf Claudication

Lower 1/3 Calf Claudication

Foot Claudication

30% Buttock & Hip Claudication±Impotence – Leriche’s Syndrome

DDx of Leg Pain1. Vascular

a) DVT (ask for risk factors)b) PVD (claudication)

2. Neurospinala) Disc Diseaseb) Spinal Stenosis (Pseudoclaudication)

3. Neuropathica) Diabetesb) Chronic EtOH abuse

4. Musculoskeletala) OA (variation with weather + time of day)b) Chronic compartment syndrome

Physical Examination:Examination: What do to:

Inspection

Expose the skin and look for:

• Thick Shiny Skin• Hair Loss • Brittle Nails• Colour Changes (pallor)• Ulcers• Muscle Wasting

Palpation • Temperature (cool, bilateral/unilateral)• Pulses: ?Regular, ?AAA• Capillary Refill• Sensation/Movement

Auscultation • Femoral Bruits

Ankle Brachial Index (ABI)

= Systolic BP in ankle Systolic BP in brachial artery

Buerger’s Test • 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:

NON INVASIVE:Duplex Ultrasound normal is triphasic biphasic monophasic absent

BLOOD TESTS:1. FBE/EUC/Homocysteine Levels 2. Coagulation Studies 3. Fasting Lipids and Fasting Glucose4. HBA1C

WHEN TO IMAGE:1. To image = to intervene2. Pt’s with disabling symptoms where revascularisation is considered3. To accurately depict anatomy of stenosis and plan for PCI or Surgery4. Sometimes in pt’s with discrepancy in hx and clinical findings

ANGIOGRAPHY:

Non-invasive:• CT Angiogram• MR Angiogram

Invasive:• 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 angiographyValue 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 Cessationb) Rigorous BSL controlc) BP reductiond) Lipid Lowering Therapy

3. MEDICAL MANAGEMENT:a) Antiplatelet therapy e.g.

Aspirin/Clopidogrel b) Phosphodiesterase Inhibitor

e.g. Cilostazol c) Foot Care

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)

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.

? Embolism (AF/Recent Infarct/Anuerysm) ? Thrombosis of native vessel or graft

?Trauma

MUST RULE OUT ACUTE LIMB ISCHEMIA

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 FindingsFurther 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 sluggisho No pulses palpable below L femoral arteryo All pulses palpable but appear reduced in R lego 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

2. ORDER INVESTIGATIONSa) FBEb) EUCc) Coagulation Studiesd) Group and Holde) 12 Lead ECGf) Chest XR

3. INITATE ACUTE MANAGEMENT:a) Analgesiab) Commence IV heparinc) Call Radiology for Angiography if limb still viabled) Discuss with registrar:

i) Thrombotic cause ?cathetar induced thrombolysis

ii) Embolic cause ?embolectomyiii) All other measures not possible

Bypass/Amputation

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

Mr. X’s Complication- 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 AcidosisoHyperkalemiaoARF (myoglobinuria)oNon-cardiac APO

2) Compartment Syndrome = oMay need fasciotomy

Learning Outcomes1. 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

• 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

• http://www.imagingpathways.health.wa.gov.au/includes/dipmenu/limb_is/summary.html