1) Acute limb ischemia is a sudden decrease in blood flow to a limb that threatens viability and requires urgent treatment. It has an incidence of about 1.5 cases per 10,000 people per year. 2) Causes include arterial embolism (from cardiac or arterial sources), native arterial thrombosis, arterial thrombosis after intervention, and arterial injury. 3) Diagnosis involves history, physical exam assessing pain and function, and imaging tests like Doppler ultrasound and angiography. 4) Treatment depends on viability of the limb and includes oxygen, fluids, anticoagulation, analgesia, and revascularization through catheter-directed thrombolysis, open surgery, or bypass if other options fail. Comp

1. Acute Limb Ischemia
Dr Manjil Malla
Resident,General surgery

2. • Acute limb Ischemia
 sudden decrease in limb perfusion that threatens limb viability
and requires urgent evaluation and management
 Incidence approximately 1.5 cases per 10,000 persons per year

3. Etiology
1.Arterial embolism
• Cardiac source
Atrial fibrillation
Myocardial infarction
Endocarditis
Valvular disease
Atrial myxoma
Prosthetic valves

4. • Arterial source
 Aneurysm
Atherosclerotic plaque
• Paradoxical embolus
venous thrombus that traverses a cardiac defect to access the
arterial circulation

5. 2. Native arterial thrombosis
• Atherosclerotic plaque
• Aneurysm thrombosis
• Arterial dissection
• Arterial entrapment/compression
Popliteal entrapment
Thoracic outlet syndrome
• Thrombophilia
• Low flow state

6. 3.Arterial thrombosis following intervention
• Vein bypass graft
• Prosthetic bypass graft
• Angioplasty site
• Stent/stent-graft site

7. 4.Arterial Injury
• Iatrogenic
Thromboembolism
Closure devices
Device embolization
• Traumatic

8. Diagnosis
• History
Leg symptoms in ALI relate to pain or function.
Duration and intensity of the pain and
presence of motor or sensory changes.
 Previous Hx of claudication, heart disease or aneurysm, and
atherosclerotic risk factor

9. • Physical Examination:
Six Ps
1.Pain
located distally in the extremity
gradually increases in severity
progresses proximally with increased duration of ischemia
2.Pallor
3. Poikilothermia
4. Pulselessness
5. Paresthesia
6. paralysis

10. Investigations
• Doppler US (to detect blood flow)
Best initial test
Diminished or absent Doppler flow signal distal to site of occlusion
• Angiography(DSA, CTA, MRA)
Digital subtraction angiography (DSA) is the imaging modality of choice.
Should only be performed if delaying treatment for further imaging does
not threaten the extremity

11. Clinical categories of ischemia

13. Embolism vs Thrombosis

15. Management
• Oxygen delivered by facemask
• Correct dehydration , IV fluid resuscitation
• Systemic anticoagulation with IV heparin bolus followed by continuous infusion
Prevents clot propagation + maintains collateral vessel
Dose: bolus 80 U/kg then drip 18 u/kg/hr
Keep aPTT ratio 2-3
• Adequate analgesia

16. Management

17. • Nonviable limb :
 Condition of extremity (or portion of extremity) in which loss of
motor function, neurological function, and tissue integrity cannot
be restored with treatment.
• Salvageable limb :
Condition of extremity with potential to secure viability and
preserve motor function to the weight-bearing portion of the foot
if treated
2016 AHA/ACC Lower Extremity PAD Guideline

18. REVASCULARIZATION FOR ALI(Recommendations)
• For viable,non threatened Limb
Urgent Angiography to localize site of occulusion
Revascularization Procedure(open or catheter-directed thrombectomy or
thrombolysis
within 6 to 24 hours
• For marginally or immediately threatened limbs(Category IIa and IIb ALI)
 Emergency Revascularization within 6 hrs
First-line: catheter-directed thrombolysis and/or percutaneous mechanical
thromboembolectomy (e.g., balloon catheter embolectomy)
Second-line: open thromboembolectomy
2016 AHA/ACC Lower Extremity PAD Guideline

19. Revascularization Procedure
SURGICAL EMBOLECTOMY
• Pros
 Rapid revascularization
Can be done via low tech instrument
Transfemoral approach can be done via local anesthesia
• Cons
 Vessel injury
 Reperfusion syndrome
Low success rate if ischemia >24 hour
Adjunct by “Intraoperative thrombolysis”

21. INTRA-OP THROMBOLYSIS
Pros
Adjunct to surgical thromboembolectomy
Clear residual thrombus in the small arteries
and arteriole
Minimal risk of bleeding
Cons
 May be inadequate in some patients with
extensive distal and small vessel thrombosis
A.J. Comerota and R. Sidhu. (2009. Can Intraoperative Thrombolytic Therapy assist with the Management of Acute Limb Ischemia?
Seminars in Vascular Surgery

22. A.J. Comerota and R. Sidhu. (2009). Can Intraoperative Thrombolytic Therapy assist with the Management of Acute Limb Ischemia?
Seminars in Vascular Surgery

23. Catheter-based thrombolysis
• Effective for patients with ALI and a salvageable (viable or
marginally threatened) limb Particularly in setting of
recent occlusion,
thrombosis of synthetic grafts
stent thrombosis
2016 AHA/ACC Lower Extremity PAD Guideline

24. Contraindication of Thrombolysis
• Absolute contraindications
Prior intracranial hemorrhage
Known structural cerebral vascular lesion
Known malignant intracranial neoplasm
Ischemic stroke within three months (excluding stroke within
three hours)
Suspected aortic dissection
Active bleeding or bleeding diathesis (excluding menses)
Significant closed-head trauma or facial trauma within three
months

25. • Relative contraindications
History of chronic, severe, poorly controlled hypertension
Severe uncontrolled hypertension on presentation (SBP >180 mmHg or DBP
>110 mmHg)
History of ischemic stroke more than three months prior
Traumatic or prolonged (>10 minute) CPR or major surgery less than three
weeks
Recent (within two to four weeks) internal bleeding
Noncompressible vascular punctures
Recent invasive procedure
Pregnancy
Active peptic ulcer
Pericarditis
Current use of anticoagulant (eg, warfarin sodium) that has produced an
elevated international normalized ratio (INR) >1.7 or prothrombin time (PT)
>15 seconds
Age >75 years

26. MECHANICAL THROMBECTOMY
Percutaneous mechanical thrombectomy (PMT)
as adjunctive therapy to thrombolysis
Trellis device (Mechanical mixing device)
insert the wire for mechanical thrombus fragmentation

27. • AngioJet®
Using a high-velocity saline jet to extract the thrombus in an isovolumic
manner “Venturi effect

28. • Pros
Disrupts the thrombus Allows better penetration of the clot by a
thrombolytic agent
 ↓ Thrombolytic dosing
 ↓ Therapy time Increasingly being used in “class IIb”
Done via percutaneous approach with local anesthesia
Less vessel injury
• Cons
 Can be used only large vessel
 Expensive device
Cronenwett, Jack L.; Johnston, K. Wayne. Rutherford's Vascular
Surgery 8th edition , Chapter 161 - 162

29. ARTERIAL BYPASS SURGERY
• Pros
 Use in patient that…
 Failed other procedures Our last resort!!!
 Severe tissue injury
 Peripheral vascular disease
 Main treatment for thrombosed popliteal artery
aneurysm

30. • Amputation* :
 Performed as the first(index) procedure in
 Nonsalvageable (class III) limb
 Low potential of limb salvage
 Risk of reperfusion syndrome

31. • Monitored and treated (e.g., fasciotomy) for compartment syndrome
after revascularization (due to reperfusion causing edema)
• Indications
 Raised intra compartment pressure (> 30 mmHg)
Clinical: increased pain, tense muscle, or nerve injury
 Category IIb ischemia for whom time to revascularization is > 4
hours
2016 AHA/ACC Lower Extremity PAD Guideline

32. Complication of Acute Limb Ischemia
1. Limb Loss
2. Death
3. Compartment Syndrome
4. Reperfusion Effects
5. Volkmann Ischemic Contracture

33. Reperfusion Effects
• Local
 Reperfusion injury – paradoxical death of already dying muscles after
reperfusion
• Systemic
 Reperfusion syndrome
 Hypotension
 ARDS
 Lactic acidosis
 Hyperkalemia
 Renal failure

34. Thank You