Limb Threatening Ischemia

1
Limb Threatening Ischemia

• Vic V. Vernenkar, D.O.
• General Vascular Surgery

2
Introduction

• An acute or chronic process that, if left
  untreated, may result in amputation
• Occurs due to a sudden decrease in the blood flow
  to a limb, with a resultant threat not only to
  the limb, but to the patient as a whole
• Does not specify etiology
• Prompt recognition
• Determine if the patient needs emergent treatment
  or less urgent work-up

3
Introduction

• Limb hypoperfusion results in systemic acid-base
  and electrolyte abnormalities
• Impair cardiopulmonary and renal function
• Reperfusion can result in release of toxic free
  radicals, further compromising these fragile
  patients
• Patient expectations not often realistic

4
Classification of Ischemia
5
Clinical Presentation

• Rest Pain
• May be the first symptom of severe ischemia
• Other causes of leg and foot pain
• Pain localized to forefoot below ankle
• Dependent rubor, pallor on elevation
• Pulses absent

6
Clinical Presentation

• Rest Pain
• Usually does not occur unless the patient has at
  least two significant occlusive arterial lesions
• Aorto-iliac SFA
• Femoral-Popliteal Distal tibial

7
Clinical Presentation

• Nonhealing Ulcers
• May be the result of ischemia
• Healing is affected by infection, pressure,
  improper medical treatment
• HP will help assess why
• Neuropathy

8
Clinical Presentation

• Gangrene
• A classic sign of ischemia
• Dry vs. Wet
• Microemboli
• Bluish, mottled spots, painful
• Emboli originate most commonly from heart,
  aneurysms, or ulcerated plaques

9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
Clinical Presentation

• Acute arterial ischemia
• Sudden onset
• Pain, pallor, paresthesia, pulselessness,
  paralysis
• History of rest pain or claudication
• History of a bypass graft
• History of arrhythmias
• If no previous symptoms, think embolus

16
Diagnostic Evaluation

• Tests should be selected to provide the maximum
  amount of information
• Minimum amount of discomfort
• Minimum delay
• Remember time is the enemy

17
Noninvasive Vascular Testing

• Doppler and PVR are simple and accurate
• Ischemia associated with ankle pressures of less
  than 35mmHg in non-diabetics and 55mmHg in
  diabetics
• Foot ulcers have a greater likelihood of healing
  if gt65mmHg in non-diabetics and gt90mmHg in
  diabetics
• Ankle Brachial Index

18
Noninvasive Testing

• Plain films may show osteomyelitis
• Bone scans if above negative
• Infection needs to be active for 2-3 weeks to be
  seen on x-ray
• ECG, Holter monitoring
• Echo
• Ultrasound for embolic sources

19
Arteriography

• Gold standard, but not without risks
• Gives surgeon a road map
• Aortogram vs. Transfemoral
• In radiology suite or in OR
• Renal failure, allergic reactions
• Local complications

20
Aorto-Iliac Disease
21
Tibial Disease
22
Superficial Femoral Disease
23
Popliteal Aneurysm Thrombosis
24
Hypercoagulable States

• Should be analyzed in patients with atypical
  thromboses, or early onset
• Adults 20-40 years of age
• Recurrent thromboembolic events
• Family history of early onset atherosclerotic
  disease

25
Hypercoagulable States

• Familial platelet aggregability
• Protein C, Protein S deficiencies
• Anticardiolipin antibody
• Lupus-like anticoagulant
• Homocysteine levels
• Antiphospholipid antibodies
• Factor V Leiden

26
Management

• Begins after it is determined if this acute or
  chronic
• Acute limb ischemia is usually caused by
  thromboembolus, popliteal aneurysm thrombosis,
  graft occlusion.

27
Management

• Thrombosis of a chronic stenosis may cause
  temporary pain, pallor and paresthesias, but
  usually it does not progress to paralysis.
• In chronic cases the acute symptoms usually
  resolve because of collaterals

28
Chronic Critical Ischemia

• Associated with at at least two levels of
  hemodynamically significant occlusions
• Symptoms are more insidious
• Aorto-iliac
• Femoropopliteal
• Distal tibial disease

29
Chronic Critical Ischemia

• Foot protection from further injury
• Avoid tape
• Lambs wool, Rooke boot
• Gauze between the toes
• Lotions
• Reverse trendelenberg
• Control local infection, control blood glucose

30
Immediate Treatment

• Systemic heparinization with 5000-10000 units iv
  then 1000 units/h
• Prevents further propagation of thrombus
• Saves branches from thrombosis
• Administer a narcotic for pain while tests are
  being arranged
• Elevate head, lower feet, protect skin

31
Initial Diagnostic Tests

• Complete Blood count
• Electrolytes
• Glucose
• Coagulation studies
• Platelet count
• ECG
• ABI, Doppler signals

32
Emergency Arteriogram

• Determine location of occlusion
• Inflow
• Outflow
• Exploration in the OR should be undertaken if
  embolus suspected
• Arteriogram in OR if necessary
• Irreversible nerve and muscle damage at 6h

33
Choice of Operation

• Depends on underlying pathology
• Fogarty embolectomy through femoral approach
• Popliteal embolectomy through popliteal approach
• Send clot to pathology
• Post op anticoagulation

34
Embolectomy
35
Choice of Intervention

• If graft occlusion is cause, regional
  thrombolysis may reopen the graft and reveal the
  cause
• Once the cause is identified, a more focused
  operation or endovascular procedure can be
  undertaken
• Bypass grafting

36
Wake Up, Its Over!

• Early recognition
• Intelligent use of noninvasive and invasive
  testing
• Multispecialty involvement
• Multiple modalities of treatment available