dicuss management , diagnosis , treatment of acute limb ischemia

1. Management of Acute Limb Ischemia
2/20/2024 1

2. Definition
•Acute Limb Ischemia (ALI) is sudden decrease in
limb perfusion causing a potential threat to limb
viability.
•Presentation is up to 2weeks following the
acute event.

3. Etiology
•Arterial embolism
•Acute arterial thrombosis
•Arterial injury
•Acute arterial dissection

4. Arterial Embolism
•Embolic occlusion of a previously unobstructed
vessel generally results in the most severe forms
of acute ischemia
•Suspected in patients with :
- acute onset , no intermittent claudication
- risk of embolism(atrial fibrillation)
- unilateral abnormal finding

5. Source of Emboli
• Cardiogenic 80%
Atrial Fibrillation 50%
Myocardial infarction 25%
other 5%
• Non Cardiac 10%
Aneurysmal disease 6%
Proximal artery Atheroma 3%
Paradoxical emboli 1%
• Other or idiopathic 10%

7. Acute Arterial Thrombosis
•Generally occurs in vessels affected by pre -
existent atherosclerosis
•Ischemia is often less severe than with
embolism)presence of collaterals)
•Location of occlusion may play a role in the
severity of limb ischemia

8. Trauma-fracture tibia

9. Aortic Dissection

10. Diagnostic Criteria: Six P’s
•Pain: usually first symptom
• May be sudden ,sever ( acute) as in trauma or embolus; often
with thrombosis the pain is insidious but becomes more sever
gradualy
• Pain is usually present throughout the entire limb, compared
with CLI in which it is most commonly described over the
forefoot

11. Diagnostic Criteria: Six P’s
•Paresthesia: sign of progressive ischemia
• The myelinated fibers of proprioception and light sensation are
lost early in acute ischemia
• Larger sensory nerves (temperature, pain, pressure) are
maintained unless prolonged ischemic time ensues.

12. Diagnostic Criteria: Six P’s
•Pallor:Indicates major obstruction to the leg
• Initial pallor may be followed by a gradual improvement
secondary to collateral filling
• In the absence of collateral circulation, the limb will become
waxy and marble white

13. Physical Examination

14. Diagnostic Criteria: Six P’s
•Paralysis: true paralysis rarely occurs; more often
motor deficit/weakness begins to occur and is an ominous sign
• Absent dorsi- and plantar flexion indicate loss of extensor and
flexor muscles of lower leg
• After 8 hours of absolute ischemia skeletal muscle becomes
rigid, contracted, and unsalvageble

15. Diagnostic Criteria: Six P’s
• Pulselessness: Absolute prerequisite of acute ischemia;
comparison to the other limb vital
• The importance of an accurate and thorough pulse
examination cannot be overemphasized
• Pt with pulses should lead the clinician to look for other
sources of pain

16. Diagnostic Criteria: Six P’s
• Poikilothermia:“cold limb”, again comparison to the
contralateral limb very important

17. Clinical Evaluation of Acute Ischemia (Clinical Picture)
Signs of acute ischemia
5Ps
Pain: symptom
+
Pulseless
Pale
Parasthesia
Paralysis
Palpation
Femoral Popliteal
Posterior tibial Dorsalis pedis
Palpate peripheral pulses, compare with the other side & write it
down on a sketch
Temperature: the limb is cold with a level of temperature change
(compare the two limbs)
Slow capillary refilling of the skin after finger pressure

18. Clinical Evaluation of Acute Ischemia (Clinical Picture)
Signs of acute ischemia
5Ps
Pain: symptom
+
Pulseless
Pale
Parasthesia
Paralysis
Palpation
Loss of motor function:
Indicates advanced limb threatening ischemia
Late irreversible ischemia: Muscle turgidity
Intrinsic foot muscles are affected first, followed by
the leg muscles
Detecting early muscle weakness is difficult
because toes movements are produced mainly by
leg muscles

19. Clinical Evaluation of Acute Ischemia (Clinical Picture)
Signs of acute ischemia
5Ps
Pain: symptom
+
Pulseless
Pale
Parasthesia
Paralysis
Palpation
Loss of sensory function
Numbness will progress to anesthesia
Progress of Sensory loss
Light touch
Vibration sense
Proprioreception
Deep pain
Pressure sense
Late

20. Marble white right
foot in acute limb
ischaemia

22. Embolism:
Obvious cardiac source
No hx of claudication
Normal pulses in contralateral limb
Few collaterals
Angiogram: minimal atherosclerosis
Clinical differentiation between thrombosis & embolism
Thrombosis:
No obvious cardiac source
History of claudication
Decreased pulses in contralateral limb
Well developed collaterals
Angiogram: diffuse atherosclerosis

24. Site of occlusion
Peripheral pulse – Area of pain – Area of ischemia

26. SVS Criteria for Limb Viability
• Class I: Not immediately threatened; no sensory or motor loss, audible
Doppler signals (arterial and venous signals)
• Class IIa: Marginally threatened; salvageable, needs urgent treatment;
minimal/no sensory loss; no motor deficit; +/- audible arterial, audible venous
signal
• Class IIb: Immediately threatened; warrants urgent intervention; +++ sensory
loss, possible rest pain; mild muscle weakness; usually inaudible signals,
audible venous signal
• Class III: Irreversible; major tissue loss and permanent nerve damage
probable; profound sensory and motor deficits (possible paralysis); inaudible
arterial and venous systems

27. Acute limb Ischemia
Rutherford class - II

28. Acute limb Ischemia
Rutherford class - III

29. Severity of Ischemia
• Reversible
Mild : pain, pallor, cold limb
Moderate : paresthesia, paresis
Severe : analgesia, paralysis, muscle tenderness
• Irreversible
Fixed staining skin(mottling), muscle rigor

30. Algorithm to be followed…
Patient with
suspected ischemia
History Examination investigations
Acute limb ischemia confirmed and staged

31. Investigations
The severity and duration of ischemia at the time
of presentation provides a narrow margin of
time for investigations

32. Investigations
• Basic Laboratories/ECG,CXR
• Doppler /Duplex US
• CTA
• MRA
• Angiography

33. CXR & ECG

34. Echocardiography

35. Duplex US

36. Acute Embolism Acute Thrombosis

39. Angio-imaging of the popliteal trifurcation before and after selective
balloon embolectomy.

41. CT angiography showing the presence of an intraluminal aortic (short arrow) and iliac (long
arrow) saddle embolus.

43. Angiogram showing bilateral occlusions of superficial femoral arteries in thighs.
Collaterals arising from the profunda femoris artery can functionally bypass this
occlusion.

44. Management
• Heparin!!! Should be a reflex reaction: Prevents clot
propagation and distal thrombosis
• Aggressive resuscitation should be undertaken as these pts
tend to be old, malnourished and dehydrated; often should be
placed in ICU
• CBC, CMP, Coags, CEs, CXR, EKG
• Invasive monitoring: a-line, CVP, foley
• .

45. Management
• For a viable limb, the options include:
–Thromboembolectomy for pt with clinical picture of
acute embolic ischemi (acute presentation, normal
contralateral limb, suspected source)
–This is unlikely to treat a stenosed artery or
thrombosed graft: In such cases, treatment options
lean toward a surgical bypass vs. thrombolysis vs.
observation

46. Management
• Pts with irreversible ischemia:
– Complete neuro deficit, tense muscles, and a mottled limb from
capillary breakdown warrant amputation
– Attempts at revascularization usually prove futile and risk renal and
cardiac toxicity from reperfusion syndrome
– Overall prognosis very poor

47. Revascularization
• Surgical revascularization
• Endovascular procedures
Thrombolytic therapy (CDT)
Percutaneous mechanical thrombectomy

48. Surgical Revascularization
• Ideal treatment for arterial embolism
Rapid diagnosis
identified source of emboli
rapid systemic coagulant
surgical embolectomy
• Embolectomy
timely operation is the goal
preoperative preparation should be rapid without time waste

49. Site of occlusion
Peripheral pulse – Area of pain – Area of ischemia

51. Groin incision
Landmark : midpoint from Pubic
Symphysis to ASIS

53. EMBOLECTOMY

54. EMBOLECTOMY

56. Technical consideration

57. Technical Consideration
Goals : Inflow Vessel Forceful Pulsatile Blood flow

58. EMBOLECTOMY
• Inflow/Out Flow Vessel
Several passes until no further
thrombus is extracted
• Avoid forceful attempt to pass
catheter
• Always examine extracted
thrombus

59. EMBOLECTOMY
• Heparinized saline infusion after embolectomy
• Assess adequacy of revascularization
clinical examination
Hand-held doppler/duplex scan
completion angiography
• Additional step if incomplete removal
intra-operative thrombolysis

60. Compartment syndrome
• Clinical presentation
pain out of proportion
paresthesia
edema
• Compartment pressure >20mmHg
clear indication of fasciotomy

61. Compartment Syndrome
• Low threshold to perform fasciotomy: You will never be criticized for
performing an unnecessary fasciotomy but you will regret not performing one
when warranted
• Extremity compartment pressures >30 mandate opening up all compartments
• Pulse exam not a reliable indicator
• Treat reperfusion injury: aggressive hydration, alkalinize the urine (minimize
toxic myoglobin)

62. Role of Fasciotomy
• Indicated in class II ischemia.
• Relieve intra compartment pressure.
• Permits inspection of the muscles and there viability.
• Disadvantages:
• Closed muscles exposed to environment leading to
incresed infection
• Increased morbidity and hospital time.

63. Compartment syndrome

64. Compartment syndrome

65. Fasciotomy : Methods

66. Wound debridement

67. Thrombolysis
• No role of systemic thrombolysis
• Catheter directed thrombolysis
less invasive
reduced mortality
• Initial treatment of choice for class 1 and class11a
• Mostly for arterial thrombosis ( not embolic)
• Advantages :
reduced risk of endothelial trauma
clot lysis in small branch vessels
gradual low pressure perfusion

68. Technique in Thrombolysis
• Perform angiography
Access from remote to interventional site
• Pass guide wire through clot
• Place multiple side hole catheter
• Infuse lytic agent(tPA)
• Serial follow up angiograms
• If no progress perform surgical intervention
• Success
• ful thrombolysis follow by treatment of any underlying
lesion(angioplasty/stenting)

69. Contraindication to thrombolysis
• Absolute
CVA (include TIA) with in 2months
active bleeding diathesis
recurrent GI bleed with in 10 days
Neurosurgery with in 3months
intracranial trauma with in 3 months

70. Contraindication to thrombolysis
• Relative
CPR with in 10 days
Major non vascular surgery or trauma with in 10 days
Uncontrolled HTN ( Systolic BP>180, Diastolic BP>110)
Intracranial Tumor
Recent Eye Surgery

71. Percutaneous Mechanical Thrombectomy
• Percutaneous Aspiration Thrombectomy
• Percutaneous Mechanical Thrombectomy
Combination with CDT
Speed up clot lysis
Reduces dose of thrombolysis

72. Amputation
• Incidence of major amputation up to 25%
10% irreversible ischemia
10-15% amputation after revascularization