lower extremity vascular disease. anatomy anatomy

Lower Extremity Lower Extremity Vascular DiseaseVascular Disease

AnatomyAnatomy

PathophysiologyPathophysiology

Most predominant cause is Most predominant cause is atherosclerotic disease atherosclerotic disease

Other causes include Other causes include antiphospholipid syndrome, popliteal antiphospholipid syndrome, popliteal aneurysms, adventitial cystic aneurysms, adventitial cystic disease, popliteal artery entrapment, disease, popliteal artery entrapment, and trauma. and trauma.


Collateral circulation allows for blood flow Collateral circulation allows for blood flow to all areas of the lower extremity in the to all areas of the lower extremity in the face of localized occlusive disease face of localized occlusive disease

Muscle arterial resistance can be Muscle arterial resistance can be decreased to allow a large increase in decreased to allow a large increase in blood flow. This is physiologic during blood flow. This is physiologic during exercise and compensatory during exercise and compensatory during ischemiaischemia

As occlusive disease progresses, it usually As occlusive disease progresses, it usually involves multiple sites in the lower involves multiple sites in the lower extremity vasculature extremity vasculature


The first symptoms are noted by the The first symptoms are noted by the patient during exercise because the patient during exercise because the leg is no longer able to increase leg is no longer able to increase blood delivery in the normal fashion blood delivery in the normal fashion

ClaudicationClaudication, is reproducible lower , is reproducible lower extremity muscle pain on walking extremity muscle pain on walking that is relieved by rest that is relieved by rest

Most commonly, it involves the calf. Most commonly, it involves the calf.


As ischemia progresses, pain is As ischemia progresses, pain is encountered at rest. encountered at rest.

With critical ischemia, the patient With critical ischemia, the patient experiences experiences rest painrest pain and wounds and wounds are unable to heal, so that the are unable to heal, so that the patient is predisposed to infection, patient is predisposed to infection, gangrene, and limb lossgangrene, and limb loss


Rest painRest pain initially begins in the initially begins in the forefoot (metatarsalgia) and toes and forefoot (metatarsalgia) and toes and progresses proximally. progresses proximally.

Patients often notice a beneficial Patients often notice a beneficial effect of gravity on their arterial effect of gravity on their arterial blood flow. blood flow.


Many let their legs hang over the side Many let their legs hang over the side of the bed in a dependent fashion to of the bed in a dependent fashion to increase the effect of gravity, which increase the effect of gravity, which augments minimal perfusion and augments minimal perfusion and decreases pain. decreases pain.

Conversely, symptoms of rest pain Conversely, symptoms of rest pain are provoked and worsened when the are provoked and worsened when the extremity is elevated extremity is elevated

Risk FactorsRisk Factors

DiabetesDiabetes Smoking #1 preventable causeSmoking #1 preventable cause HTNHTN GeneticsGenetics ObesityObesity HyperlipidemiaHyperlipidemia HypercholesterolemiaHypercholesterolemia

Patient EvaluationPatient Evaluation

History of pain (type, location position)History of pain (type, location position) Non-healing ulcer, infectionNon-healing ulcer, infection Past medical history of diabetes, HTN, Past medical history of diabetes, HTN,

cardiac, hypercholesterolemia, cardiac, hypercholesterolemia, hypercoagulable stateshypercoagulable states

Social history (smoking, activity level)Social history (smoking, activity level) Family historyFamily history

Physical ExamPhysical Exam

Full vascular examinationFull vascular examination Appearance (color, hair, muscle, Appearance (color, hair, muscle,

nails, skin)nails, skin) Touch (temp, refill, tenderness, Touch (temp, refill, tenderness,

elevation)elevation) PulsesPulses StethoscopeStethoscope Neck, AbdomenNeck, Abdomen Heart Heart

Non-invasive TechniquesNon-invasive Techniques

Ankle-Brachial IndexAnkle-Brachial Index Useful in predicting the likelihood of Useful in predicting the likelihood of

wound healingwound healing Amputations healed in all patients Amputations healed in all patients

with an ABI above 70% with an ABI above 70% Healing did not occur in 25% of those Healing did not occur in 25% of those

with an ABI below 70% with an ABI below 70%

Non-invasive TechniquesNon-invasive Techniques Simple and inexpensive Simple and inexpensive In diabetics is often unreliable because of In diabetics is often unreliable because of

abnormal wall calcification and abnormal wall calcification and noncompressibility noncompressibility

Additional information can be obtained by Additional information can be obtained by measuring pressures at various levels of measuring pressures at various levels of the lower extremity the lower extremity

Gradients of more than 20 mm Hg are Gradients of more than 20 mm Hg are diagnostic of a hemodynamically diagnostic of a hemodynamically significant lesion significant lesion

Duplex UltrasoundDuplex Ultrasound Exercise stress test can be performed Exercise stress test can be performed

Invasive TechniquesInvasive Techniques

Angiography is the gold standard for Angiography is the gold standard for evaluating lower extremity ischemic evaluating lower extremity ischemic disease disease

Done before OR for precisionDone before OR for precision From aorta to feetFrom aorta to feet

Invasive TechniquesInvasive Techniques

Hemodynamically significant lesions Hemodynamically significant lesions are identified by a reduction in the are identified by a reduction in the cross-sectional area of 75% or more cross-sectional area of 75% or more or a 50% decrease in diameter or a 50% decrease in diameter

Dye load a problem for renal Dye load a problem for renal patients, anaphylaxis (<3%), local patients, anaphylaxis (<3%), local and distal complications (<1-2%)and distal complications (<1-2%)

Not done if no intervention planned!Not done if no intervention planned!

TreatmentTreatment

Claudication or limb threatening?Claudication or limb threatening? When limb-threatening, intervention When limb-threatening, intervention

is necessaryis necessary Claudication lifestyle limiting?Claudication lifestyle limiting? Co-existing problems, high or good Co-existing problems, high or good

risk patient?risk patient? Surgery or endovascular?Surgery or endovascular?

ConservativeConservative

Stop smokingStop smoking WalkWalk Preventative foot care in diabeticsPreventative foot care in diabetics Control of blood glucose levelControl of blood glucose level Decrease cholesterol levelsDecrease cholesterol levels Drug therapyDrug therapy

DrugsDrugs

PentoxyphyllinPentoxyphyllin (Trental), a (Trental), a hemorrheologic drughemorrheologic drug

Increases blood filtration and Increases blood filtration and decreases platelet aggregation and decreases platelet aggregation and plasma fibrinogen plasma fibrinogen

DrugsDrugs

Decrease in viscosityDecrease in viscosity Increases blood flow in the lower Increases blood flow in the lower

extremity and increases muscle extremity and increases muscle oxygen tensionoxygen tension

DrugsDrugs

CilostazolCilostazol (Pletal), a (Pletal), a phosphodiesterase inhibitor that phosphodiesterase inhibitor that suppresses platelet aggregation and suppresses platelet aggregation and acts as a direct vasodilator acts as a direct vasodilator

TiclopidineTiclopidine, an adenosine , an adenosine diphosphate inhibitor, also decreases diphosphate inhibitor, also decreases blood viscosity blood viscosity

Endovascular TherapyEndovascular Therapy

Discrete lesions of the superficial and Discrete lesions of the superficial and deep femoral arteries have been deep femoral arteries have been successfully treated with percutaneous successfully treated with percutaneous transluminal angioplasty transluminal angioplasty

Balloon causes the atherosclerotic Balloon causes the atherosclerotic intima to rupture and stretches the intima to rupture and stretches the mediamedia

Increased blood flow allows for Increased blood flow allows for continued patency continued patency


The atherosclerotic lesion can also The atherosclerotic lesion can also re-form over time re-form over time

Best results are observed in those Best results are observed in those with short focal lesionswith short focal lesions

Success rates are higher in larger Success rates are higher in larger vesselsvessels


Good runoff is important for patency Good runoff is important for patency Distal disease increases the risk for Distal disease increases the risk for

restenosis and failure, and the restenosis and failure, and the consequences would be devastating consequences would be devastating if acute thrombosis were to occur if acute thrombosis were to occur during the procedure.during the procedure.

Endovascular TherapyEndovascular Therapy PTA has also been used successfully as an PTA has also been used successfully as an

adjunct to surgery to improve inflow for a adjunct to surgery to improve inflow for a more distal bypass and outflow for a more more distal bypass and outflow for a more proximal bypass proximal bypass

Stenosis in bypass grafts is also amenable to Stenosis in bypass grafts is also amenable to PTA PTA

In the event of acute lower extremity In the event of acute lower extremity ischemia, an immediate angiogram is optimal ischemia, an immediate angiogram is optimal and fibrinolytic therapy may be warrantedand fibrinolytic therapy may be warranted

Catheter is inserted into the clot and the Catheter is inserted into the clot and the fibrinolytic agent is infused into the clot fibrinolytic agent is infused into the clot during the ensuing hours along with heparin. during the ensuing hours along with heparin.

Surgical TherapySurgical Therapy


Optimize other medical problemsOptimize other medical problems Debride and treat infectionsDebride and treat infections AngiogramAngiogram


Endarterectomy, bypass, amputationEndarterectomy, bypass, amputation Bypass is indicated for the patient Bypass is indicated for the patient

with critical ischemia and, in specific with critical ischemia and, in specific instances, the patient with instances, the patient with claudicationclaudication

Surgical TherapySurgical Therapy Both the physician and the patient must be Both the physician and the patient must be

certain that the disease is truly certain that the disease is truly incapacitating incapacitating and and limitslimits the activities of the activities of daily living daily living

That conservative and medical management That conservative and medical management have been unsuccessful, and that the have been unsuccessful, and that the mortality risk and threat of limb loss as a mortality risk and threat of limb loss as a complication of surgery are worth the complication of surgery are worth the possible relief of symptoms possible relief of symptoms

Remember! claudication progresses to critical Remember! claudication progresses to critical ischemia and limb loss in relatively few casesischemia and limb loss in relatively few cases

All interventions in the peripheral circulation All interventions in the peripheral circulation can be complicated by limb loss!can be complicated by limb loss!


Inflow and outflow vesselsInflow and outflow vessels RunoffRunoff Vein (reversed or in-situ)Vein (reversed or in-situ) GraftGraft

ComplicationsComplications

Perioperative mortality has been reported Perioperative mortality has been reported to be between 2% and 5% to be between 2% and 5%

Perioperative myocardial infarction rates Perioperative myocardial infarction rates have been reported as 3% have been reported as 3%

If silent and unnoticed myocardial If silent and unnoticed myocardial infarctions are included, they may be as infarctions are included, they may be as high as 10% to 15%high as 10% to 15%

Hemorrhage, hematoma, thrombosis, Hemorrhage, hematoma, thrombosis, infection, and edemainfection, and edema

Primary amputation (when?) Primary amputation (when?)

lower extremity vascular disease. anatomy anatomy

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