Post on 17-May-2020
6/14/2018
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Peripheral Arterial Disease
Jeff Horn, MD FACS RPVI
University Surgical Associates
June 14, 2018
Disclosures
• I have no financial relationships to disclose
Who We Are
• University Surgical Associates • 8 Vascular Surgeons • Treat all vascular conditions (carotid, aorta, mesenteric, peripheral,
dialysis, venous) • Facility for clinic, procedures, diagnostic imaging, prosthetics
Overview
• Background
• Signs & Symptoms
• Diagnosis
• Natural History
• Treatment
• Case Examples
Background
• 8-12 Million in US alone • >200 Million worldwide • Increased prevalence
– Age – Smoking – Diabetes – Hypertension – Hypercholesterolemia – Non-hispanic black race – Chronic renal insufficiency – Hyperhomocysteinemia
• 2008 PAD costs exceed $200B
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Background
• Associated with severe morbidity and mortality
• Interruption of occupation
• Impaired activities of daily living
• Impacts quality of life
• Can affect independence
• Significant cost of care
Background
• PAD can be asymptomatic or symptomatic
• Can present as acute or chronic condition
• Symptomatic patients have Intermittent Claudication (IC), Atypical leg pain, Rest Pain or Tissue Loss
• Rest Pain and Tissue Loss = Critical Limb Ischemia (CLI)
Associated Mortality Signs of PAD
• Hair loss
• Slow hair growth
• Change in color
• Atrophy of limb
• Changes in toenails
Symptoms
• IC is reproducible discomfort in certain muscle groups during activity that is relieved by rest
• Comes from latin “to limp” • Calf muscles most common, but can be thighs,
buttocks or hips • Usually muscle group below stenosis/occlusion
– Commonly see calf pain, nonpalpable popliteal pulse
• Patients with PAD risk factors commonly have other inhibitors of proper leg function – Myopathy, arthritis, spine disease, neuropathy
• Symptomatic to Asymptomatic is around 1:3
Symptoms
• 30-60% of PAD asymptomatic
• 30-50% have symptoms other than classic IC
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Atypical Symptoms Atypical Symptoms
• Those with atypical scenarios (exertional pain at exertion and rest) had worse functional outcomes
• Disease of nerves, muscles, balance, arthritis – More muscle fat, decrease fat density – More neuropathy and spinal disease – Poor muscle fuel oxidation / mitochondria function
• Carry on group does the best, less depression, more motivation
• Faster decline in those without classic IC • Be wary of those with low ABI and no symptoms – they
may just not be very active • Some adjust activity level to avoid ambulatory pain
Diagnosis
• Ankle Brachial Index (ABI) is most common
• ABI < 0.9 or >1.4 highly suggestive of poor cv outcomes
• ABI < 0.9 high sensitivity and specificity for PAD (79-95% sensitivity, >95% specificity)
• Can be done in any clinical setting using handheld continuous doppler
• With compelling history be wary of normal ABI (send for exercise ABI)
Diagnosis
Diagnosis
• ABI results:
– >1.4 Calcific noncompressable arteries (need TBI)
– 1.0-1.39 Normal
– 0.9 – 0.99 Borderline
– 0.5-0.89 Moderate PAD
– 0.0 – 0.49 Severe PAD
Diagnosis
• History
– Duration, character, timing, relief, exacerbation
– Gradual or abrupt?
• Physical Exam
– Detailed pulse evaluation
– Skin integrity
– Physical maneuvers to simulate symptoms (leg elevation for nerve related pain)
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Diagnosis
• Pulse Exam
– Aorta, femoral, popliteal, dp, pt
– Quality of pulse?
– Greater than expected?
– Absent?
– Aneurysm?
Diagnosis
• Pulse Volume Recordings (PVR)
• Segmental Pressures
• Duplex Ultrasound
• CTA
• MRA
• Angiography
• Be careful with radiology reports – always recommended to get more advanced and $$ tests
Diagnosis Duplex
• Not indicated as first test (ABI)
• Noninvasive • Relatively fast (30-60
minutes) • Identify degree of plaque
AND flow characteristics • Inexpensive compare to
others • Accurate in the right hands
CTA
• A noninvasive arteriogram • Definition in multiple planes • Relatively quick acquisition • Expensive • Contrast load (nephrotoxic,
allergies) • Poor delineation in heavily
calcified arteries • Non-physiologic, detail depends on
contrast timing
MRA
• Very expensive
• Multiple modalities used (T1, T2, TOF)
• Contrast load
• Length of exam, patient comfort, anxiety
• Pacemakers, other hardware
• Worse resolution than others
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Angiography
• Gold standard in vascular diagnosis • Invasive • Expensive • Time-consuming • Contrast load issues (less than bolus dose with
CT) • Ability to treat at the same time as diagnosis • Ability to get hemodynamic data • Complication rates low but not zero (access site,
dissections, perforations, emboli)
Diagnosis
• Rutherford scale for chronic vascular insufficiency
Diagnosis
• Natural history of PAD
• Claudicants divided into 1/3’s
– 1/3 improve, 1/3 same, 1/3 decline
– Risk of amputation <1% / year
• CLI patients fare MUCH worse
– Risk of amputation ~50%
– Risk of death all causes at 5 years ~ 50%
Asymptomatic Management
• No clear benefit derived from screening for PAD in asymptomatic patient
• Accepted risk factor modification for atherosclerosis in general
• Smoking cessation, antiplatelet therapy, statin therapy, exercise therapy, surveillance
• In general invasive therapy only indicated for those with symptoms
IC Management
• Significant systemic burden of atherosclerosis
• Risk factor modification can
– Reduce cardiac complications and death
– Improve interventional complication rates
– Improve durability / patency of procedure
Smoking
• Endothelial damage • Platelet and leukocyte adhesion • Endothelial permeability • Impaired vascular tone • Vasoconstrictor effects of endothelin-1 • Abnormalities of platelet function, coagulation
and fibrinolysis • Increased blood viscosity • IC develops in smokers 2x rate of nonsmokers,
also dose dependent
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Smoking Cessation
• Quiters show increase ABI and increased walking distance on treadmill test
• Smokers have 2-3x risk of lower extremity bypass graft failure
• Those who quit have 2x survival benefit compared to those who don’t
Diabetes
• Prevalance of PAD in diabetics is ~30%
• Amputation rates 5-10x higher in diabetics
• Sensory disturbances of the extremity
• Increased risk of peripheral infections
Hypertension
• Typically associated with CV disease in this population
• Treatment to reduce risk of all cause cardiovascular mortality
Antiplatelets/Antithrombotics
• No evidence that dual therapy better than single agent for PAD
Agents to Improve Function
• Trental (Pentoxyfylline) – Reduces blood viscosity – Retard platelet aggregation – 400mg 3x/day up to 1800mg/day – Can exacerbate HTN
• Pletal (Cilostazol) – Suppresses platelet aggregation – Direct vasodilator – Improvement in pain-free walking distance in 3-4wks – Contraindicated in heart failure – 100mg TID
Exercise Therapy
• Metanalysis of 1200 pts shows improvement in walking ability of 50-200% up to 2yrs
• Enlargement of existing collaterals, induced angiogenesis, vasodilation of microcirculation
• Medical comorbidities may preclude participation • Walking, running, cycling either self directed or supervised • Walking is best, no benefit to intensity level • >30 minutes per session • >3 sessions / week • >26 weeks in duration • Structured / supervised plans have better outcomes
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Revascularization
• Benign natural history of IC vs loss of ambulatory function on ADL, occupation and QoL
• Majority who adhere to program will decline slow or not at all
• BUT 1/3 will progress to significant disability • Those that seek treatment out of fear of amputation need
be reassured • Moderate claudication in vigorous patient can be
debilitating • Severe claudication may be well tolerated in the sedentary • In most claudicants a 3-6 month trial of lifestyle
modification and medical therapy is warranted
Revascularization
• Options include Endovascular Therapy or Open Surgical
• EVT includes angioplasty, stenting, atherectomy, antiproliferative pharmacotherapy
• Open surgical can be In-line or extra anatomic
• Procedures called “inflow” and “runoff”
• Other terms include infrainguinal (below groin) and infrageniculate (below knee)
Aortoiliac
• “Inflow” disease
• Can cause hip, buttock pain and ED
– Leriche Syndrome
• Can also manifest as calf pain
• Check femoral pulses
• One instance where CTA can be helpful prior to intervention
Aortoiliac
Aortoiliac EVT
• Techniques include antegrade, retrograde, brachial, contralateral
• Balloon expandable, self expandable and covered stent options
• Hybrid options if disease in the common femoral artery
• Initial technical success 90-100%
• 1 yr primary / secondary patency 70-100% / 90-100%
• 5 yr primary / secondary patency 60-85% / 80-95%
Aortoiliac Open
• Direct “in-line” and extra anatomic bypass
• Aortofemoral bypass (Y graft) gold standard
• 10yr patency >80%
• Commonly with Dacron or ePTFE graft but can be cryopreserved aorta, or vein
• Perioperative mortality <3%
• Morbidity 10-15%
• Extra-anatomic options include Ax-fem, fem-fem
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Aortoiliac Open Infrainguinal
• SFA is the most common site of obstruction leading to IC
• Severity of symptoms related to degree of collateral network, status of profunda
• EVT considered when risk modification and exercise fail to improve functional status
• Predictors of success include lesion length, degree of stenosis, size of artery and calcium
Infrainguinal Infrainguinal
• Strategies – PTA alone
– PTA with bailout stenting
– Primary stenting (self expanding, covered)
– Atherectomy alone
– Atherectomy with PTA +/- BOS
– Drug coated balloon DCB
– Drug eluting stent DES
– Atherectomy with DCB
Infrainguinal Infrainguinal
• Primary or bailout stenting can confer a patency advantage over PTA alone
• Useful when PTA introduces dissection / injury
• Useful when immediate arterial recoil / ineffective PTA
• Nitinol material, flexible
• Not recommended behind the knee
• Inherit fracture risk, improved with newer iterations
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Infrainguinal
• Covered stents (Viabahn, iCast, Fluency)
– Useful in longer lesions (endopass)
– Useful in lesions with thrombus
– Now heparin bonded
Infrainguinal
• Atherectomy devices remove plaque
– Different techniques
– Lesion and location dependent
– Expensive
– Long term data has not born out effectiveness
– Used more for vessel prep than standalone therapy (subsequent PTA or DCB)
Atherectomy Devices
Directional Atherectomy - Hawk portfolio: Silver Hawk,
TurboHawk, & HawkOne (Medtronic) - Pantheris (Avinger)
Orbital Atherectomy - Diamondback 360 (CSI)
Rotational Atherectomy - JetStream (Boston Scientific) - Phoenix (Volcano)
Photoablation Atherectomy - Turbo-Elite & Turbo-Tandem
(Spectranetics)
Infrainguinal
DA RA OA Laser Composition
X X Ca2+
X X X X Soft
X X Thrombus
Morphology DA RA OA Laser
Focal X X
CTO X X X
Eccentric X X
Concentric X X X X
DA RA OA Laser Location
X X X X Above-knee
X X X Below-knee
ISR DA RA OA Laser
Indication X
Anatomical Location
Plaque Composition
Lesion Morphology
In-Stent Restenosis
Individual operator experience and preference are likely the primary influencers in device selection.
Infrainguinal
• Antiproliferative treatments (Paclitaxel)
– Delivers drug to arterial wall during deployment
– Drug concentration, delivery complex
– Vessel prep prior to delivery to ensure it goes to smooth muscle
– Difficult to deliver appropriate drug if circumferential calcium
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Drug Coated Balloon
55
1. Freedom from core laboratory-assessed restenosis (duplex ultrasound PSVR ≤2.4) or clinically-driven target lesion revascularization through 36
months (adjudicated by a Clinical Events Committee blinded to the assigned treatment).
2. Number at risk represents the number of evaluable subjects at the beginning of each 30-day window.
Δ +24.4%
Drug Eluting Stent
Infrainguinal
• Complications related to EVT:
– Access site (PSA, bleeding, infection)
– Contrast delivery
– Arterial injury (dissection, embolism, rupture)
– Burning bridges (comprimising future bypass options, change of outflow level)
– Covered stents go down hard (covered collaterals)
Infrainguinal Open
• Bypass is mainstay of treatment for IC for 5 decades
• Durable treatment with improvements in walking distance, ABI and pain-free walking time
• Important factors include conduit used, quality of inflow, number and quality of outflow vessels, target location
• In IC vein is recommended above and below the knee as first line conduit
• Certain vessels better with plaque removal (common femoral, profunda)
Infrainguinal Infrainguinal
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Infrainguinal Infrainguinal
Infrainguinal
• Lower extremity bypass complications
– Intraoperative mortality low
– SSI 2-10%
– Vein harvest dehiscence
– Graft failure
– Graft infection
– Bleeding
Critical Limb Ischemia
• “End stage” vascular disease • Huge burden of therapy and cost
– Wound care, rehabilitation, multiple interventions, medical comorbidities
– $43,000/pt-year (1990 data)
• Require multidisciplinary approach – Primary care, VS, podiatry, infectious disease, critical care
• Risk of amputation at this level approaches 40-50% at one year • Risk of overall mortality approaches 50% at 5 years • Some (~40-50%) may not proceed from asymptomatic to IC to CLI • May not be referred early in disease course • Tend to have multilevel disease (inflow and runoff vessels)
Critical Limb Ischemia
• Rest pain
– Pain in muscles whether ambulatory or not
– Frequently exacerbated in elevated position
• Tissue loss
– Slow healing wounds
– Ulcerations
– Gangrene (wet / dry)
Critical Limb Ischemia
• Goals of therapy – Relieve ischemic pain – Heal wounds – Prevent limb loss – Improve function and QoL – Prolong survival
• Nonoperative therapy in those unfit for intervention (advanced wound care) – 38% amputation rate, wounds healed in only 50% at
one year
• ABI < 0.5 predictor of limb loss
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Critical Limb Ischemia
• EVT good first line intervention – Ability to diagnose mulitlevel obstruction – Simultaneous treatment – Reperfuse angiosome target if possible
• Bypass first option for extensive disease – Survival and amputation-free survival similar on
outcomes at 2 years – Beyond 2 years, bypass patients fared much better
(especially vein bypass)
Critical Limb Ischemia
Critical Limb Ischemia
• WIfI System of CLI classification
Critical Limb Ischemia
Acute Limb Ischemia (ALI)
• If new onset within last two weeks
• Acute interruption of blood supply
• May be first manifestation of PAD
• 1.5 cases per 10,000
• New or worsening claudication, rest pain, absent distal pulses, mottling of skin, petechia, motor loss, sensosory loss, cold skin
• 30 day amputation rate as high as 30%
ALI
• Emboli of cardiac origin in 75% of cases • Dissection, embolism, entrapment, trauma, cyst,
hypercoagulable state, graft/stent failure • 6 P’s
– Pain – Pallor – Paresthesia – Paralysis – Poikilothermia – Pulselessness
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ALI
• History and physical very important
• Exact moment of change
• History of arrhythmia
• Normal pulses in opposite limb
• Motor and sensory exams
• Pain in muscle compartments
ALI
ALI
• Strategies are all operative • Immediate heparinization • Endovascular
– Aspiration thrombectomy – Pharmacomechanical
thrombectomy
• Open – Arteriotomy and fogarty
thrombectomy
• Amputation • Fasciotomy
Cases
• 1. CB 45 yo WF
– 1 year of progressive ambulatory discomfort
– Now with rest pain in the calves
– HTN, smoker, obesity, hypercholesterolemia
– Absent femoral pulses
– Monophasic distal pulses
– ABI 0.5 / 0.5
• 2. DB 68 yo AAF
– HTN, former smoker, DM, ESRD
– New onset left first toe gangrene
– Palpable femoral pulse
– Weak monophasic PT pulse
– Delayed capillary refill
– ABI 0.35
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Cases
• 81 yo WF
– HTN, former smoker
– Very active
– Followed in clinic for 18 months
– Prior visits show SFA stenosis, ABI 0.78, no lifestyle limitation
– This year ABI drop to 0.6, difficult ambulation
Cases
• 52 yo Construction Worker
– Former smoker, severe CAD, HLD, HTN
– Can’t walk 100 yds without stopping
– ABI 0.7, SFA occlusion
– Getting progressively worse
– Interferes with occupation
Thank You!
Questions??