Acute limb ischemia

64 yr old male with previous history of

heart attack came to casualty with c/o sudden onset of pain in the right leg below the knee.

On examination….

Absent popliteal and lower pulsations Decreased sensations Inability to move toes

Acute limb ischemia

EtiologyEtiology of of acute limb ischemiaacute limb ischemia

Acute arterial embolism:

Acute traumatic ischemia:

Of a relatively Of a relatively health arterial treehealth arterial tree

Acute arterial thrombosis: Of a previously Of a previously diseased arterial treediseased arterial tree

Patho-pysiologyPatho-pysiology

Acute Embolic IschemiaAcute Embolic Ischemia

An embolus suddenly

occludes a relatively

healthy arterial tree

It usually arrest at arterial

bifurcation

Aortic bifurcation

Iliac bifurcation

Femoral bifurcation

Popliteal trifurcation

An embolus can originate from the heart (MS with atrial fibrillation, MI with mural

thrombus) or dilated diseased arteries (aortic aneurism)

Example of acute arterial embolus

“Saddle” Embolus of right iliac artery

Acute Thrombotic Acute Thrombotic IschemiaIschemia

AtherosclerosisAtherosclerosis causes

progressive narrowing of the

arterial tree

Sluggish flow & rough surface will favor acute

thrombosis

Stimulates development of

collaterals

Clinical PictureClinical Picture

Clinical Evaluation of Acute Ischemia Clinical Evaluation of Acute Ischemia (Clinical Picture)(Clinical Picture)

Signs of acute ischemiaSigns of acute ischemia

5P5PsPainPain: symptom

++

PulselessPulseless

PalePale

ParasthesiaParasthesia

ParalysisParalysis

InspectionInspection

COLOR:

EarlyEarly: pale

LaterLater: cyanosed mottling fixed mottling & cyanosis

Pallor

Reversible mottling

An area of fixed cyanosis

surrounded by reversible mottling

Empty veins: compare the Rt. (ischemic) & Lt. (normal)

Fixed mottling & cyanosis




++

PulselessPulseless

PalePale


ParalysisParalysis

PalpationPalpation

FemoralFemoral PoplitealPopliteal

Posterior tibialPosterior tibial Dorsalis pedisDorsalis pedis

Palpate peripheral pulsesPalpate peripheral pulses, compare with the other side & write it down on a sketch

TemperatureTemperature: the limb is cold with a level of temperature change (compare the two limbs)

Slow capillary refillingSlow capillary refilling of the skin after finger pressure




++

PulselessPulseless

PalePale


ParalysisParalysis

PalpationPalpation

Loss of sensory function

Numbness will progress to anesthesia

Progress of Sensory loss

Light touch

Vibration sense

Proprioreception

Deep pain

Pressure sense LateLate




++

PulselessPulseless

PalePale


ParalysisParalysis

PalpationPalpation

Loss of motor function:Loss of motor function:

Indicates advancedadvanced limb threatening ischemia

Late irreversible ischemia: Muscle turgidity

Intrinsic foot muscles are affected first, followed by the leg muscles

Detecting early muscle weakness is difficult because toes movements are produced mainly by leg muscles

Investigations

The severity and duration of The severity and duration of ischemia at the time of ischemia at the time of presentation provides a presentation provides a

narrow margin of timenarrow margin of time for for investigationsinvestigations

general investigations CK [Patients with a

suspected hypercoagulable state will need additional studies seeking:]

Anticardiolipin antibodies

Elevated homocysteine concentration

Antibodies to platelet factor IV

Doppler USDoppler US

to assess the level of obstruction & severity of ischemia

What are welooking for?

NORMAL• Multiphasic

• Pulsatile• Regular amplitude

An audible Doppler signal assures some blood flow No Doppler signals, a vascular surgeon should be immediately consulted

0.7 to 0.9 is mild disease,0.5 to 0.69 is moderate disease,< 0.5 is severe disease.

ArteriographyArteriography

If the differentiation between embolic & thrombotic ischemia is not clear clinically, and if the limb condition permits,

DO ANGIOGRAPHYDO 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

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Embolism:

obvious cardiac source

No hx of cluadication

Normal pulses in contralateral limb

Angiogram: minimal atherosclerotic

Few collateral

Thrombosis:

No obvious cardiac source.

history of cluadication.

abnormal pulses in contralateral limb.

Angiogram: diffuse atherosclerotic

Well developed collateral

CategoryCategory DescriptionDescription Cap. refillCap. refill ParalysisParalysis Sensory Sensory lossloss

AA VV

II ViableViable Not immediately Not immediately threatenedthreatened

IntactIntact -- -- AudAud AudAud

IIaIIa ThreatenedThreatened Salvagable if Salvagable if treatedtreated

Intact/slowIntact/slow -- PartialPartial __ AudAud

IIbIIb ThreatenedThreatened Salvagable if Salvagable if treated treated emergentlyemergently

Slow/absentSlow/absent PartialPartial PartialPartial __ AudAud

IIIIII IrreversibleIrreversible Primary Primary amputation req.amputation req.

AbsentAbsent CompleteComplete CompleteComplete __ __

DopplerDoppler

TREATMENT

Goals of therapy include restoration of blood flow,

preservation of limb and life, and prevention of recurrent

thrombosis

IMMEDIATE CARE

THROMBOLYTICS

SURGERY

A. Immediate care

Anticoagulation Analgesia measures to improve existing perfusion treatment of associated cardiac

conditions

B B Catheter directed Catheter directed thrombolysisthrombolysis

Agents used: Streptokinase, Urokinase, tissue plasminogen

activator

IndicationsIndications:

1. Viable or marginally threatened limb (class I, IIa)

2. Recent acute thrombosis (not suitable for embolism or old thrombi)

3. Avoid patients with contraindications

ContraindicationsContraindications::

AbsoluteAbsolute:

1. Cerebro-vascular stroke within previous 2 months

2. Active bleeding or recent GI bleeding within previous 10 days

3. Intracranial trauma or neurosurgery within previous 3 months

RelativeRelative:

1. Cardio-pulmonary resuscitation within previous 10 days

2. Major surgery or trauma within previous 10 days

3. Uncontrolled hypertension

SURGERY

OPERATIVE REVASCULARISATION AMPUTATION

Fogarty balloon catheter (with post-op anti coagulants)

Surgery [Surgery may be considered in trauma, where there

are contraindications to CDT, or where CDT is not available.

The method of revascularization (open surgicalor endovascular) may differ depending on:

Anatomic location of occlusion Etiology of ALI Contraindications to open or endovascular

treatment Local practice patterns]

Amputation

for irreversible ischemia with permanent tissue damage

Clinical outcomes• Mortality -15–20%.

• Major morbidities include:

1. Due to major bleeding 10–15% of patients require transfusion/and or operative intervention

2. Amputation (25–30% of patients)3. Fasciotomy (5–25% of patients)4. Renal insufficiency (up to 20% of patients)

Follow-up care

warfarin, often for 3–6 months or longer.

Patients with thromboembolism will need long-term anticoagulation, possibly lifelong.

If contraindicated due to bleeding risk factors>> platelet inhibition therapy

Algorithm to be followed…

Patient with suspected ischemia

History Examination investigations

Acute limb ischemia confirmed and staged

Heparin

I IIA IIb III

AMPUTATION

EMERGENCYOPERATIVE

RE-VASCULARISATION

EARLY INTERVENTION

NO YES

TREAT FORCHRONIC ISCHEMIA

SAME AS FOR IIa

Management of IIa

ARTERIOGRAPHY

No lesion

Discrete localized lesions

Multiple extensive lesions

Health & Medicine

Acute limb ischemia