INTERNAL MEDICINE - Vascular Diseases of the Extremities

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INTERNAL MEDICINE:

Vascular Diseases of the Extremities

VASCULAR DISEASES OF THE EXTREMITIES – Arterial Disorders

PERIPHERAL ARTERIAL DISEASE: -Definition: stenosis or occlusion in the aorta or

arteries of the limbs -atherosclerosis is the leading cause of PAD in

patients >40 years old -other causes: -thrombosis -embolism -vasculitis -fibromuscular dysplasia -entrapment -cystic adventitial disease -trauma


PERIPHERAL ARTERIAL DISEASE:

-the highest prevalence of atherosclerotic PAD occurs in 60s-70s

-Risk Factors:

-cigarette smoking -hypercholesterolemia

-DM -hypertension

-hyperhomocysteinemia


PERIPHERAL ARTERIAL DISEASE: Pathology: -stenosis or occlusion are usually LOCALIZED TO

LARGE AND MEDIUM SIZED VESSELS -include the ff: 1. Atherosclerotic plaques w/ calcium deposition 2. Thinning of the media 3. Patchy destruction of muscle & elastic fibers 4. Fragmentation of the internal elastic lamina 5. Thrombi composed of platelets and fibrin


PERIPHERAL ARTERIAL DISEASE: -Primary sites of involvement: 1. femoral and popliteal arteries 2. tibial and peroneal 3. abdominal aorta and iliac arteries *atherosclerotic lesions occur preferentially at : a.) arterial branch points b.) sites of increased turbulence c.) altered shear stress d.) site of intimal injury


PERIPHERAL ARTERIAL DISEASE: -S/Sx: -50% are asymptomatic -MOST COMMON SYMTPOM: INTERMITTENT

CLAUDICATION -Definition: pain, ache, cramp, numbness or

sense of fatigue in the muscles, occurs during exercise and relieved by rest, common in lower than upper extremities

-the site of claudication is DISTAL to the location of the occlusive lesion e.g. calf claudication- femoral/popliteal lesion


PERIPHERAL ARTERIAL DISEASE: -S/Sx: -pts may complain of rest pain commonly at night when legs

are horizontal and improve when legs are on dependent position

-absent/decreased pulses distal to obstruction -bruits -muscle atrophy -hairloss -thickened nails -smooth and shiny skin -decreased skin temperature -pallor/cyanosis

ISCHEMIC NEUROPATHY: -numbness -hyporeflexia SEVERE ISCHEMIA: -edema


PERIPHERAL ARTERIAL DISEASE: -Non-invasive Testing *History and physical examination are often sufficient to

establish the diagnosis of PAD 1. Arterial Pressure -placement of sphygmomanometric cuffs at the

ankles and use of a Doppler device to auscultate or record blood flow from the dorsalis pedis and posterior tibial arteries

-NORMAL arms and legs SBP are equal, but ANKLE PRESSURE may be slightly HIGHER DUE TO PULSE-WAVE AMPLIFICATION

-SBP in ankle is DECREASED IN STENOSIS



-Non-invasive Testing

2. Ankle:Brachial Index

-NORMAL: > 1.0

-PAD: < 1.0

-Severe ischemia: < 0.5

3. Duplex Ultrasonography

-image and detect stenotic lesions in native arteries and bypass grafts


PERIPHERAL ARTERIAL DISEASE: -Non-invasive Testing 4. Treadmill Testing / Stress test -allows physician to assess functional limitation

objectively -decline in ABI immediately after exercise

provides further support for the Dx of PAD 5. Magnetic Resonance Angiography, CT

angiography, contrast angiography -not for routine testing but done prior to

revascularization



-Non-invasive Testing

6. Other tests

-segmental pressure measurements

-pulse volume recordings

-doppler flow velocity waveform analysis

-transcutaneous oximetry



-Prognosis:

-influenced primarily by coexistence of:

1. coronary artery disease

2. cerebrovascular disease

-most is highest with the most severe PAD

-It can be worse in patients who continue to smoke cigarette and those with DM



-Rx:

1. Risk factor modification and antiplatelet therapy should be intiated to improve cardiovascular outcomes

2. Cessation of cigarette smoking

-counseling and adjunctive drug therapy with nicotine patch, bupropion or varenicline increases cessation rates and reduces recidivism


PERIPHERAL ARTERIAL DISEASE: -Rx: 3. ACE inhibitors – symptomatic PAD 4. B-adrenergic blockers – HTN with coexistent CAD -reduce post revascularization complications 5. Statins NCEP – LDL cholesterol <100mg/dl 6. Clopidogrel -inhinits platelet aggregation via its effect on

ADP-dependent platelet fibrinogen binding -more efficient than aspirin in decreasing M&M



-Rx:

7. Cilostazol – phosphodiesterase inhibitor with vasodilator and antiplatelet properties, increases claudication distance

8. Pentoxifylline – xanthine derivative; decreases blood viscosity to increase red cell flexibility, increasing blood flow to the microcirculation and enhancing tissue oxygenation


PERIPHERAL ARTERIAL DISEASE: -Rx: *WARFARIN not used in patients with CHRONIC PAD 9. Supportive measures -meticulous care of feet -shock blocks under the head of the bed and canopy

over the feet -exercise regularly and at progressively more

strenuous levels (30-45 min session, 3-5 times/wk for 12 weeks)

-advise to walk until near maximum caludication discomfort occurs, then resting until the symptoms resolve before resuming ambulation



-Rx:

10. Revascularization

-indicated for pts with disabling, progressive, or severe symptoms of intermittent claudication despite medical therapy or those with critical limb ischemia


FIBROMUSCULAR DYSPLASIA: -Definition: -hyperplastic disorder affecting medium-sized and

small arteries -common in FEMALES -usually involves RENAL and CAROTID arteries but

can affect extremity vessels, most common are the ILIAC ARTERIES

- “string of beads”” appearance


FIBROMUSCULAR DYSPLASIA:

-Histologic classifications:

1. Intimal Fibroplasia

2. Adventitial Hyperplasia

3. Medial Dysplasia

a. medial fibroplasia

-MOST COMMON

b. perimedial fibroplasia

c. medial hyperplasia


FIBROMUSCULAR DYSPLASIA:

-S/Sx:

1. Claudication

2. Rest pain

-Tx:

1. Percutaneous Transluminal angiography (PTA)

2. Surgical reconstruction


THROMBOANGITIS OBLITERANS / BUERGER’S DISEASE:

-Definition:

-an inflammatory occlusive vascular disorder involving small and medium-sized arteries and veins in the distal upper and lower extremities

-common in men <40 years

-with definite relation to cigarette smoking



-Pathogenesis: INITIAL STAGE: polymorphonuclear leukocytes

infiltrate arterial and venous walls internal elastic lamina is preserved but

inflammatory thrombus develops Mononuclear cells, fibroblasts and giants cells

replace the neutrophils LATER STAGES: Perivascular fibrosis, organized

thrombus, recanalization



-S/Sx:

-TRIAD

1. Claudication of affected extremity

-affects distal vessels (calves, forearms)

2. Raynaud’s phenomenon

3. Migratory superficial vein thrombophlebitis

-trophic nail changes

-reduces/absent pulses on ulna, radius, tibia

-smooth, tapering segmental lesions in the distal vessels

-collateral vessels at site of occlusio



-Dx:

-excisional biopsy and pathologic examination of the involved vessel

-Rx:

-no specific treatment EXCEPT ABSTENTATION FROM TOBACCO


ACUTE ARTERIAL OCCLUSION:

-Definition:

-results in the sudden cessation of blood flow to an extremity

-TWO PRINCIPAL CAUSES:

1. embolism

2. thrombus in situ

-paradoxically, may originate from a venous thrombus that entered the systemic circulation via a patent foramen ovale or septal defect



-EMBOLISM

-most common sources: heart, aorta, large arteries

-emboli tend to lodge at vessel bifurcation because the vessel caliber decreases at these sites

-in the lower extremities, emboli lodge more frequently in femoral A, iliac A, aorta, popliteal A and tibioperoneal A.



-THROMBUS IN SITU

-occurs more frequently in atherosclerotic vessels at the site of an atherosclerotic plaque or aneurysm and in arterial bypass grafts

-may complicate arterial punctures and placement of catheters

-associated with polycythemia and hypercoagulable disorders



-S/Sx:

-severe pain, paresthesia, numbness, coldness develop in the involved extremity within 1 hour

-paralysis may happen in severe ischemia

-loss of pulses distal to occlusion

-pallor/cyanosis

-hyporeflexia/areflexia

-weakness and muscle stiffening



-Dx:

1. Arteriography

-useful in confirming Dx and demonstrating location and extent of occlusion


ACUTE ARTERIAL OCCLUSION: -Rx: 1. Heparin -to prevent propagation of clot 2. Throboembolectomy/Arterial bypass procedure 3. Intraarterial thrombolytic therapy with

recombinant tissue plasminogen activator or urokinase

*meticulous observation for hemorrhagic complications is required during intraarterial thrombolytic therapy


ATHEROEMBOLISM:

-Definition:

-multiple small deposits of fibrin, platelets, and cholesterol debris embolize from proximal atherosclerotic lesions or aneurysmal sites

INTERNAL MEDICINE - Vascular Diseases of the Extremities

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