Acute Limb Acute Limb IschemiaIschemia

Acute Limb IschemiaAcute Limb Ischemia Sudden occlusion of an artery, decrease in limb perfusion Sudden occlusion of an artery, decrease in limb perfusion

that threatens limb viability and requires urgent that threatens limb viability and requires urgent evaluation and management , commonly due to acute evaluation and management , commonly due to acute thrombosis, embolic event, or trauma. It often will happen thrombosis, embolic event, or trauma. It often will happen when thrombosis occur a pre-exiting atheroma (so-called when thrombosis occur a pre-exiting atheroma (so-called ‘acute on chronic deseas ’)‘acute on chronic deseas ’)

Incidence is 14/100,000 (12 % of operations performed in Incidence is 14/100,000 (12 % of operations performed in the average vascular unit)the average vascular unit)

Causes of acute arterial Causes of acute arterial occlusion occlusion

Embolus : greater risk of deathEmbolus : greater risk of death Thrombosis : greater risk of deathThrombosis : greater risk of death OthersOthers TraumaTrauma IatrogenicIatrogenic Arterial dissectionArterial dissection 2/3 of pts will require immediate 2/3 of pts will require immediate

amputationamputationIn absence of interventionsIn absence of interventions

Clinical differentiation Clinical differentiation between thrombosis & between thrombosis &

embolismembolismEmbolism :Embolism :Obvious cardiac sourceObvious cardiac sourceNo history of claudicationNo history of claudicationNormal pulse in Normal pulse in contralaterals limbcontralaterals limbFew collateralsFew collateralsAngiogram : minimal Angiogram : minimal atherosclerosisatherosclerosis

Thrombosis :Thrombosis :No obvious cardiac sourceNo obvious cardiac sourceHistory of claudicationHistory of claudicationDecreased pulses in Decreased pulses in contralateral limbcontralateral limbWell developed Well developed contralateralscontralateralsAngiogram : diffuse Angiogram : diffuse atherosclerosisatherosclerosis

Source for an embolus :Source for an embolus :

Spontaneous (80%) Cardiac source arrhythmias, MI, prosthetic valve, endocarditis Non-Cardiac source Proximal AS plaque, Proximal Aneurysm,

Paradoxical emboli

Iatrogenic (20%) Angiographic manipulation Surgical manipulation

Cardiac emboliCardiac emboli

Can occur spontaneously or iatrogenicallyCan occur spontaneously or iatrogenically The heart is by far the predominant The heart is by far the predominant

source of spontaneous arterial emboli (80-source of spontaneous arterial emboli (80-90% cases)90% cases)

Presently , atherosclerotic heart disesase Presently , atherosclerotic heart disesase has been implicated as a causative factor has been implicated as a causative factor in 60-70% of all cases of embolus with in 60-70% of all cases of embolus with rheumatic mitral valve disease and rheumatic mitral valve disease and associated atrial fibrillation in the associated atrial fibrillation in the remaining 30-40%.remaining 30-40%.

Cardiac emboliCardiac emboli

Next to atrial fibrillation, myocardial Next to atrial fibrillation, myocardial infarction is the second most frequent infarction is the second most frequent associated with peripheral arterial associated with peripheral arterial embolization ( 20%)embolization ( 20%)

Electrocardiographic changes were Electrocardiographic changes were noted in 64% of all patients presenting noted in 64% of all patients presenting with acute extremity ischemia with acute extremity ischemia requiring surgical intervention.requiring surgical intervention.

Cardiac emboliCardiac emboli

Cardiac valvular prostheses are Cardiac valvular prostheses are another common source of emboli another common source of emboli (required permanent anticoagulant (required permanent anticoagulant therapy)therapy)

Intracardiac tumor such as atrial Intracardiac tumor such as atrial myxomas are a rare source of myxomas are a rare source of peripheral arterial emboli.peripheral arterial emboli.

Noncardiac EmboliNoncardiac Emboli

Spontaneous emboli originating Spontaneous emboli originating from non cardiac sources are noted from non cardiac sources are noted in 5% to 10% of patients.in 5% to 10% of patients.

Embolization of mural thrombus Embolization of mural thrombus associated with aortoiliac, femoral or associated with aortoiliac, femoral or popliteal aneurysms has been popliteal aneurysms has been reported.reported.

Noncardiac tumors and may gain Noncardiac tumors and may gain access to the arterial circulation and access to the arterial circulation and form arterial emboli such as primary form arterial emboli such as primary or metastatic lung carcinoma.or metastatic lung carcinoma.

An additional 5-10% spontaneous An additional 5-10% spontaneous emboli originate from a source that emboli originate from a source that remains unidentified. remains unidentified.

Common sites for embolus Common sites for embolus lodgment in the arterial tree?lodgment in the arterial tree?

Diagnostic Criteria Six P’sDiagnostic Criteria Six P’s Sudden onset of diffuse and poorly Sudden onset of diffuse and poorly

localized leg pain localized leg pain 6 Ps6 Ps Paresthesias Paresthesias Pain Pain Poikilothermia (coolness) Poikilothermia (coolness) Pallor Pallor Pulselessness Pulselessness ParalysisParalysis

Pain : usually first symptomPain : usually first symptom May be acute as in trauma or May be acute as in trauma or

embolus: often with thrombosis the embolus: often with thrombosis the pain in insidious but become pain in insidious but become unrelenting unrelenting

Pain is usually present throughout the Pain is usually present throughout the entire limb, compared with CLI in entire limb, compared with CLI in which it is most commonly described which it is most commonly described over the forefootover the forefoot

Paresthesia :Paresthesia : Sign of progressive ischemia Sign of progressive ischemia The myelinated fibers of prorioception The myelinated fibers of prorioception

and light sensation are lost early in and light sensation are lost early in acute ischemiaacute ischemia

Sensory changes occur as a result of Sensory changes occur as a result of ischemia of nerve tissueischemia of nerve tissue

Paralysis :Paralysis : More often deficit/weakness begins to occur More often deficit/weakness begins to occur

and is an ominous signand is an ominous sign Absent dorsi and plantar flexion indicate loss of Absent dorsi and plantar flexion indicate loss of

extensor and flexor muscle of lower legextensor and flexor muscle of lower leg After 8 hours of absolute ischemia skeletal After 8 hours of absolute ischemia skeletal

muscle become rigid, contractet muscle become rigid, contractet Complete motor paralysis is a late symptom Complete motor paralysis is a late symptom

signaling impending gangrene, representing a signaling impending gangrene, representing a combination of both end-stage muscle and combination of both end-stage muscle and neural ischemianeural ischemia

Pallor :Pallor : Indicate major obstruction to the legIndicate major obstruction to the leg In the absence of collateral circulation, In the absence of collateral circulation,

the limb will become waxy and marble the limb will become waxy and marble whitewhite

If untreated, the skin changes proceed If untreated, the skin changes proceed to necrosis and desquamation.to necrosis and desquamation.

Poikilothermia :Poikilothermia : ““Cold Limb”, again comparison to the Cold Limb”, again comparison to the

contralateral limb very importantcontralateral limb very important

Rutherford ClassificationRutherford Classificationfor Limb Viabilityfor Limb Viability

Society of Vascular Surgery (SVS) / International Society of Cardiovascular Society of Vascular Surgery (SVS) / International Society of Cardiovascular Surgery (ISCVS)Surgery (ISCVS)

DopplerDoppler

Rutherford Vascular Surgery.2005.p.9761-2

InvestigationsInvestigations Acute Limb Ischemia is aAcute Limb Ischemia is a CLINICAL DIAGNOSISCLINICAL DIAGNOSIS If time allows, especially if If time allows, especially if

atherosclerotic thrombosis is atherosclerotic thrombosis is suggested, preoperative suggested, preoperative angiographyangiography is often wise is often wise

Goal of treating patients Goal of treating patients with Acute Limb Ischemiawith Acute Limb Ischemia

Rapid restoration of adequate Rapid restoration of adequate arterial perfusion without the arterial perfusion without the development of morbid local development of morbid local or systemic complicationsor systemic complications

TreatmentTreatment EMEGENCY (Golden time is 6 hours)EMEGENCY (Golden time is 6 hours) ABCABC IV Heparin (anticoagulation)IV Heparin (anticoagulation) Rapid surgical Rapid surgical

thromboembolectomythromboembolectomy +/ - surgical bypass+/ - surgical bypass +/- thrombolytic therapy+/- thrombolytic therapy +/- primary amputation+/- primary amputation

Anticoagulation:Anticoagulation: Systemic anticoagulation with intravenous Systemic anticoagulation with intravenous

unfractionated heparin is immediately instituted unfractionated heparin is immediately instituted while preparations are made for surgery or while preparations are made for surgery or angiography.angiography.

An initial bolus of 5000 U is appropriate for most patients, followed by an intravenous infusion commencing at 1000 U/hr

If urgent operation is not undertaken, the infusion should be monitored using the activated partial thromboplastin time, aiming for a ratio of 2 to 3

Surgical RevascularisasiSurgical Revascularisasi Surgical approaches to the treatment of Surgical approaches to the treatment of

acute limb ischemia include acute limb ischemia include thromboembolectomy with ballon thromboembolectomy with ballon catheter, bypass surgery, and adjuncts catheter, bypass surgery, and adjuncts such as endarterectomy, patch such as endarterectomy, patch angioplasty, and intraoperative angioplasty, and intraoperative thrombolysisthrombolysis

Thrombo-embolectomy : Fogarty catheter Thrombo-embolectomy : Fogarty catheter (4 F or 5 F)(4 F or 5 F)

Surgical Thrmboemblectomy Surgical Thrmboemblectomy ProcedureProcedure

ThrombolysisThrombolysis Percutaneous thrombolysis is

now an established intervention for all forms of acute arterial occlusion

Thrombolytic agents are plasminogen activators that accelerate plasmin production with the degradation of fibrin

ThrombolysisThrombolysis

Endovascular Endovascular RevascularizationRevascularization

The goal of catheter-based endovascular The goal of catheter-based endovascular revascularization is to restore blood flow as revascularization is to restore blood flow as rapidly as possible to a variable or threatened rapidly as possible to a variable or threatened limb with the use drug, mechanical device, or limb with the use drug, mechanical device, or bothboth

Patient in whom ischemia for 12 to 24 hour would Patient in whom ischemia for 12 to 24 hour would not be safe and those with a nonviable limb, not be safe and those with a nonviable limb, bypass graft with suspected infection or bypass graft with suspected infection or contraindication to thrombolysis (e.g recent contraindication to thrombolysis (e.g recent intracranial hemorrahge, recent major surgery, intracranial hemorrahge, recent major surgery, vascular brain neoplasm, or active bleeding) vascular brain neoplasm, or active bleeding) should not undergo catheter-directed therapiesshould not undergo catheter-directed therapies

Local Local Compartment Compartment

SyndromeSyndrome Systemic Systemic HyperkalemiaHyperkalemia AcidosisAcidosis MyoglobulinuriaMyoglobulinuria

Reperfusion InjuryReperfusion Injury

Compartement syndromeCompartement syndrome

Following revascularization, significant Following revascularization, significant limb swelling may occur. This situation limb swelling may occur. This situation has the potential to result in has the potential to result in compartement syndrome, most compartement syndrome, most frequently in the anterior compartement frequently in the anterior compartement may elect to perform a fasciotomy may elect to perform a fasciotomy

Major risks fasciotomy include both Major risks fasciotomy include both

infection and bleeding infection and bleeding

Compartment SyndromeCompartment Syndrome

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