02.20 Peripheral Arterial Occlusive Disease Flashcards
Atherosclerotic occlusive disease of the arterial system distal to the aortic bifurcation
PAD
Atherosclerosis commonly occurs in:
Aortic cusps
Branches of the aorta (subclavian and carotid)
Bifurcations (aorta to iliac artery, iliac artery to the superficial and deep femoral, anterior tibial to peroneal and posterior tibial artery, lumbar and iliac arteries
Progression of atherosclerosis
Initial lesion Fatty streak Intermediate lesion forms Atheroma develops Fibroatheroma Complicated lesion
Histologically normal
Macrophage infiltration in sites of inflammation
Isolated foam cells
Inital lesion
Intima of the vessel becomes thickened because of intracellular lipid accumulation
Fatty streak
Due to intracellular lipid accumulation and small extracellular lipid pools
Intermediate lesion forms
Mixture of lipid intracellular accumulations core of extracellular lipid
Stage where disease may already become overt, presenting with clinical symptoms
Atheroma develops
Fibrotic or calcific layers
Fibroatheroma
Because the intima is no longer smooth, there are hematoma-hemorrhages and some degree of thrombosis
Complicated lesion
How lesions cause symptom
Stenosis/occlusion
Embolism
Symptoms appear if _____
Collateral circulation is poor
Artery occludes acutely
Leg attack
pain is felt in large muscle groups distal to an arterial lesion after exercise
Intermittent claudication
Severe compromise of arterial flow
Failure of compensatory mechanisms
Exacerbated by elevation
Limb threatening
Ischemic rest pain
Tissue necrosis occurs when blood flow is inadequate to maintain tissue viability even at rest
Gangrene
RF for atherosclerosis
Tobacco use Diet DM Hyperlipidemia HPN Fam Hx
Important things to elicit in Hx
Cardiopulmonary assessment
Neurological assessment
Renal assessment
Specific vascular evaluation
Inspection of skin changes Capillary refill Auscultate for bruits in central vessels Pulse examination Pulse grading
Absence of pulse
0/4
Weak (may suggest impairment)
Effort must be made to search for the pulse
1/4
Normal
2/4
Full
3/4
Bounding (may suggest aneurysm or calcification)
4/4
Classification of PAD based on the Fontaine
I - asymptomatic IIa - mild claudication IIb - moderate to severe claudication III - ischemic rest pain IV - ulceration or gangrene
Classification of PAD based on Rutherford
00 - asymptomatic I1 - mild claudication I2 - moderate claudication I3 - severe claudication II4 - ischemic rest pain III5 - minor tissue loss III6 - major tissue loss
To confirm diagnosis
To establish patient baselines
Assess RF of the patient
Non-invasive vascular testing
Non-invasive vascular testing
ABI
Doppler/Duplex waveform analysis
Segmented pressure and waveform studies
Normal ABI value
1 to a little over 1
Reflect the degree stenosis
Waveforms
Sources of error in noninvasive vascular testing
Wrong cuff width
Incompressible arteries
Operator/technician factors
Not used solely fro diagnosis, but is generally reserved for treatment planning
Invasive complex imaging
General complications of invasive complex imaging
Contrast reactions Arterial complciations Thrombosis Atheroembolism Puncture site complications
Reserved for cases when there’s a plan for intervention since it’s already an invasive procedure
Conventional angiography
Complications of conventional angiography
Hemorrhages or pseudo-aneursym formation at site of needle insertion
Too invasive
Still need IV needle and contrast
Can produce a 2D or #d picture
CT angiography
Risks/complications of CT angiographyh
Dye-induced nephrotoxicity Dye allergy Thrombosis Atheroembolism Puncture-site
Risk of MR angiography
Presence of any metallic objects in the body is CI
Invasive complex imaging
Convetional arteriography
CT angiography
MR angiography
Most important risk factor modification
Cessation of tobacco use
Overall strategy in treatment of critical limb ischemia
Relieve ischemic pain
Heal ischemic ulcers
Improve patient functionality and quality of life
Prolong survival
Primary outcome of treating CLI
Amputation-free survival
Common profile of CLI patients you will encounter
Elderly
Multiple co-morbidities
Non-ambulant/non-functional leg
Medical treatment
Cilostazol
Pentoxphylline
In patients with limb threat
Revascularization
Revascularization procedure
Percutaneous endovascular intervention
Surgical revascularization
Medical vascularization
Percutaneous endovascular intervention
Angioplasty
Atherectomy
Stenting
Surgical revascularization
Enderarterectomy
Bypass surgery
Indications for surgical management
Gangrene
Pain at rest
Non-healing arterial ulcer
Disabling claudication
Gold standard
Established long-term patencies, lim salvage and mortality outcomes
Operative bypass
Open surgical revascularization
First line teratment
Minimally invasive, more tolerated by sick patients
Angioplasty
Stenting
Minimally invasive endovascular techqnies for infra-inguinal disease
Percutaneous angioplasty PTA with stenting Atherectomy Subintimal angioplasty Percutaneous endografting
Intermediate-term outcome of angioplasty, when used preferentially for critical ischemia in anatomically suitable patients, provides very acceptable limb salvage and survival despite a relatively high stenosis rate
Primary angioplasty for critical limb ischemia
Use of VEGF and basic FGF to promote collaterall circulation growth
Medical revascularization
Single stenosis < 1 cm in length
Endovascular treatment
Endovascular
TASC-A
Multiple stenosis focal, each < 1 cm in length
Endovascular therapy is the preferred treatment even in long lesions or tandem lesions
Endovascular therapy is preferred treatment
TASC-B
Stenoses 1-4 cm in length
Short occlusions < 2cm in length
Surgery
TASC-C
Diffuse long stenosis < 4 cm in length
Occlusions > 2cm in length
Surgery
TASC-D
