Acute Arterial Occlusion the threatened limb

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Acute Arterial Occlusionthe threatened limb

• Craig A. Thompson, M.D., MMSc.
• Cardiovascular Intervention and Vascular Medicine
• Dartmouth Hitchcock Medical Center

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Goals

• Background of peripheral arterial disease
• Etiologies of acute arterial occlusion
• Diagnosis
• Management
• Case Scenarios

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Peripheral Arterial Disease (PAD)general
information

• Atherosclerosis of the peripheral arteries, or
  arteriosclerosis obliterans, PAD, is the most
  common cause of symptomatic obstruction in the
  peripheral arterial tree.1
• The prevalence of PAD increases with age
• 32 (40-59 years)
• 82 (60-69 years)
• 192 (over 70 years)
• 1. Rosenfield, K and Isner JM. Chap. 97 Textbook
  of Cardiovascular Medicine 1998
• 2. Criqui et al. Circulation 198571(3)510-515

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PAD Prevalence
Total 10 million U.S. patients
Asymptomatic 5 million
Symptomatic untreated 3.75 million
Symptomatic treated 1.25 million
Pentecost, et al. Guidelines for Peripheral
Percutaneous Transluminal Angioplasty of the
Abdominal Aorta and Lower Extremity Vessels 1993
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Outcomes in Patients with Intermittent
Claudication
PAD Prevalence and outcomes
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PAD Risk Factors
Male Gender Age (per 10 y) Diabetes Smoking Hypert
ension Hypercholesterolemia Fibrinogen Alcohol
-4 -3 -2 -1 0 1 2 3 4
Protective
Harmful
Odds Ratio
Belch JJF, et al. Arch Intern Med.
2003163884-892.
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Coexistence of Diseased Vascular Beds
PAD patients with CHD
CBVD patients with CHD
Damaraju1
Tuttle2
Erdoes3
Iyer4
Mathur5
Diethrich6
Charts from The 1999 Advisory Board Company
1. Damaraju et al. Texas Heart Institute Journal
199724285-290 2. Tuttle et al. Am J Kidney
Diseases. 199832611-622 3. Erdoes et al. Am J
Kidney Diseases 199627496-503 4. Iyer et al.
Abstract presented at Adv. Endovascular
Therapies-1999 5. Mathur et al. Circulation
1998971239-1245 6. Dietrich et al. J
Endovascular Surgery 1996342-62
PAD Peripheral arterial disease CHD Coronary
heart disease CBVD Cerebrovascular disease
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Projected Increase in the Prevalence of PAD
US individuals, (millions)
Age group
Prevalence rate 3 8
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Chart from The 1999 Advisory Board
Company Source Criqui NW, et al., N Engl J Med
(1992) Newman AB, et al., Arteriosclersis,
Thrombosis, and Vascular Biology (1999) U.S.
Census Bureau (http//www.census.gov/population/pr
ojections/nation/nas.
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Five year mortality ratesPAD versus Cancer
Criqui M. Presentation Vascular Medicine of the
Lower Extremities at the American Diabetes
Associations Scientific Sessions June 1999
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Peripheral Arterial Occlusive Disease
Mortality Rates PAD versus No PAD
Dormandy et al. J Cardiovasc Surg (Torino),
19893050-57
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Is it vascular limb pain?
Stable PADPatient History
Historical Vascular Neurogenic Clue Etiology Eti
ology Onset Predictable Variable Only
with walking? Yes No Relief with stopping
or Yes Variable standing? Absent
pedal Variable Variable pulses at rest
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Differentiating True Claudication from
Pseudoclaudication1
Intermittent Claudication
Pseudoclaudication
Character of
Cramping, tightness,
Same or tingling,
discomfort
tiredness
weakness, clumsiness
Location of
Buttock, hip, thigh, calf,
Same
discomfort
foot
Exercise induced
Yes
Yes or No
Distance to
Same each time
Variable
claudication
Occurs with standing
No
Yes
Relief
Stop walking
Often must sit or
change body positions
1. Krajewski LP, Olin JW. Chap. 11 Peripheral
Vascular Disease 2nd Ed. 1996
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Peripheral Arterial DiseasePatient History

• Questions to ask patients with possible lower
  extremity disease
• What is your typical activity level?
• Do you experience any discomfort in the calf,
  thigh, buttock or hip area that occurs with
  walking, climbing stairs?
• Describe the symptom, onset, duration and
  resolution?
• Do you experience rest pain, leg pain when in
  bed?
• Have you had any sores or skin ulcerations that
  wont heal?
• Any changes in the color, temperature or
  appearance of your skin?
• Any problems with impotence or pain in your
  genitals?

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Peripheral Arterial DiseaseIntermittent
Claudication

• Definition
• Exercise-induced lower extremity pain that is
  caused by ischemia and relieved by rest1
• Prevalence
• Approximately 3.4 million people in the US
  experience intermittent claudication2
• Primary symptom of lower-extremity occlusive
  disease2
• 1. Santilli J et al. American Family Physician
  199953(4)1245-53
• 2. Creager M, Hiatt W. Mgmt of Peripheral Artery
  Disease ACC 1999

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Peripheral Arterial Disease Rest Pain

• Characteristics
• Usually occurs at night when the person lies
  supine
• Dull aching sensation in the toes or forefoot
• Pain is relieved when legs are lowered to floor
• Indicative of severe arterial insufficiency and
  usually involves multiple arterial segments
• Krajewski LP, Olin JW. Chap. 11 Peripheral
  Vascular Disease 2nd Ed. 1996

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Classification of PAD
Jaff MR. Clinical Assessment of the Patient
With Lower Limb Ischemia. Presented at the
Advanced Endovascular Therapies-1998. The New
York Meeting, May 1998.
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Peripheral Arterial Disease Physical Exam

• Assess skin appearance
• Check for hair loss on distal limbs
• Check for edema and tenderness
• Check all pulses
• Check both pressures in upper extremity
• Check for bruits
• Brief neurologic exam
• Cardiac exam

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PAOD Diagnostic Tests

• Non-invasive tests1
• ABI (Ankle/Brachial Index)
• Exercise Test
• Segmental Pressures
• Segmental Volume Plethysmography
• Duplex Ultrasonography
• MRA (Magnetic Resonance Arteriography)
• CTA (Computed Tomography Angiography)
• Invasive tests1
• Peripheral Angiogram
• 1. Krajewski and Olin Chapter 11 Peripheral
  Vascular Disease. 2nd ed. 1996

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PAD Diagnostic TestABI (Ankle-Brachial Index)
Courtesy of Fred St. Goar MD, CVI Medical Group
Inc., Mountain View, CA
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ABI (Ankle-Brachial Index)
ABI Ankle pressure/Brachial pressure
Rice, KL and Walsh ME. Nursing 98, Feb. 1998
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Physical ExaminationInterpretation and
limitations of ABI
ABI Interpretation
Two Main Limitations Calcified ankle vessels
result in artificially normal ABI (DM,
RF) Normal ABI in patient with
Aortoiliac Disease only becomes abnormal with
exercise testing
Above 0.90 Normal 0.71-0.90 Mild
Obstruction 0.41-0.70 Moderate
Obstruction 0.00-0.40 Severe Obstruction

• Toe pressures
• Transcutaneous oxygenation (TcPO2)

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CAPRIE Study
Physical ExaminationABI-Predictor of ischemic
events
ABI inverse relationship with three-year risk
of cardiovascular events and deaths
2.5
10.2 relative risk increase per 0.1 decrease in
ABI(P 0.041)
2
Risk Relative to ABPI 1
1.5
1
0
0.2
0.4
0.6
0.8
1
ABPI
Dormandy JA. Cerebrovasc Dis. 19999 (Suppl
1)1128.
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PAOD Diagnostic Test Exercise Test

• May be useful in quantifying the severity of
  intermittent claudication
• In general, if ankle pressure falls by more than
  20 of the baseline value and requires more than
  3 minutes to recover, the test is considered
  abnormal.
• Weitz et al. Circulation 1996943026-3049

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PAOD Diagnostic Test Segmental Pressure Test
Courtesy of Fred St. Goar MD, CVI Medical Group
Inc., Mountain View, CA
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Interpretation of Systolic Limb Blood Pressures
Jaff MR., Dorros G. J Endovasc Surg.
19985146-158
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PAOD Diagnostic TestDuplex Scanning
Courtesy of Fred St. Goar MD, CVI Medical Group
Inc., Mountain View, CA
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Noninvasive Vascular StudiesPost-intervention
iliac imaging
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PAOD Diagnostic TestMagnetic Resonance
Angiography

• Uses MRI technology1
• Studies done to show efficacy1
• Owens MRA had greater sensitivity than
  conventional contrast arteriography for detecting
  distal runoff vessels2
• Cambria MRA is accurate... and in selected
  patients may eliminate the need for contrast
  arteriography...3
• Some limitations still exist1
• Diagnostic failures in patients with vascular
  clips and prosthetic joints.4
• 1. Krajewski and Olin Chapter 11, Peripheral
  Vascular Disease 2nd ed. 1996
• 2. Owens RS et al. N Engl J Med, 1992
  326(24)1577-81
• 3. Cambria RP et al. J Vasc Surg,
  199317(6)1050-6
• 4. Quinn SF et al. Radiology, 1993189(1)181-4

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Noninvasive Vascular StudiesMRA in PAD
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Noninvasive Vascular StudiesCT angiography
Left SFA Stenosis
DSA (Pre-PTA)
CTA
Right Fem-Pop BPG
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Etiologies of Acute Arterial Occlusion

• Emboli
• In situ thrombosis
• high grade native vessel of graft stenoses
• Vascular inflammatory diseases
• Trauma
• External compression
• Dissection
• Compartment syndrome
• Severe venous diseases
• Hypercoagulable states

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Cardiovascular Etiologies of Acute Arterial
Occlusion
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Acute arterial occlusionthe 5 Ps

• Pain
• Paresthesias
• Pallor
• Pulselessness
• Paralysis

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Acute Arterial Occlusionthe viable limb (class 1)

• Lack of rest pain
• Presence of pedal arterial doppler flow
• Ankle systolic pressures gt 30mmHg

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Acute Arterial Occlusionthe threatened limb
(class 2)

• Rest pain
• Mild sensory/motor deficits
• Absent arterial doppler signals
• Intact venous flow

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Acute Arterial Occlusionirreversible ischemia
(class 3)

• Profound sensory/motor dysfunction
• Absent skin capillary blood flow
• Absent arterial and venous doppler signals

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Clinical categories of acute limb
ischemiaRutherford classification
Findings
Doppler signals
Category
Sensory loss
Muscle
Arterial
Venous
weakness
I. Viable
None
None
Audible
Audible
II Threatened
a.

Marginally
Minimal/none
None
Inaudible
Audible
b.

Immediately
More than toes
Mild, moderate
Inaudible
Audible
III. Irreversible
Profound,
Profound,
Inaudible
Inaudible
anesthetic
paralysis
Rutherford et al. J Vasc Surg 199726517-38
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Acute Arterial OcclusionTreatment Options

• Endovascular Therapy
• Peripheral Transluminal Angioplasty
• Peripheral Stenting
• Atherectomy (adjunctive)
• Thrombolytic Therapy (adjunctive)
• Embolic or foreign body retrieval
• Surgery
• Bypass grafts
• Fasciotomy
• Amputation
• Endarterectomy
• Rosenfield K, Isner JM, Chap. 97 Textbook of
  Cardiovascular Medicine 1998

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Acute Arterial Occlusionconsiderations for
endovascular and surgical therapy

• Location of occlusion
• Embolism vs thrombus
• Duration of ischemia
• Native artery or graft
• Patient-related risks
• Intervention-related risks
• Contraindications to thrombolysis

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Acute Arterial OcclusionTreatment Pathway
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Conclusions

• PAD is marker for morbidity and mortality
• Limb threatening ischemia is advanced stage of
  PAD or result or acute arterial occlusion
• Acute arterial occlusion with immediately
  threatened limb or nonviable is medical emergency
  and requires prompt therapy