acute limb ischemia

2. By
DR. Sameh Attia Ali Basha
Senior Registrar Vascular Surgery
MBBCh, MSc, MRCS(A), EBVS, MD

4. Acute
ischaemia
Cronic
ischaemia
Limb ischaemia
Iscaemia means diminution of the blood
supply to the tissues or organs sufficient
to interfere with their nutrition and / or
function.

5. Acute limb ischaemia is the rapid or sudden
decrease in limb perfusion that threatens tissue
viability.
The lower limbs are more commonly affected
than the upper limbs.

6. Aetiology of acute limb ischaemia
Arterial embolism.
Arterial thrombosis.
Acute occlusion of vascular graft.
Arterial trauma.
 aortic dissection.
 compartment syndrome.
extensive iliofemoral DVT (phlemasia
alba dolens)

7. A- Arterial embolism
 Embolus means plug.
 It Occurs in healthy vessels.
 Usually occur in patients with rheumatic
heart disease.
 Classified by size or content:-
–Macro emboli and micro emboli.
–Thrombus, cholesterol.

8. Sites of impaction
Emboli tend to lodge at the bifurcation
of the artery.
The usual sites:-
- common femoral artery,
- iliac artery,
- popliteal artery,
- Aorta (saddle emboli) and
- brachial artery.

9. Source of arterial emboli
I. Cardio-arterial.
I. Arterio-arterial.
I. Veno-arterial.

10. i- Cardio-arterial embolism:
1- Rheumatic heart disease:
It was previously the most common
cardiac disorder:-
 Thrombus formation on prosthetic
valves.
 Valvular vegetation.
 Endocarditis.

11. 2- Ischaemic heart disease:
Represent more than70%of all
cardiac emboli:-
 A F.
 Transmural myocardial infarction.
 Left ventricular mural thrombus.
 Left ventricular aneurysm.
 Cardiomyopathy.

12. 3- Left Atrial myxoma:
- It is rare, but when present
,portions may break off and undergo
embolization to peripheral vessels.
- Pathologic examination of emboli
is important to identify such an
unsuspected cause.

13. ii- Arterio – arterial embolism
-From diseased proximal arteries:
 Abdominal aortic aneurysms.
 Peripheral aneurysms.
 Atherosclerotic ulcer/stenosis.
 Thrombosed prosthetic graft.
 Iatrogenic source.

14. iii- Veno - arterial embolism:
Paradoxical embolization.
Less than 0.5% of patients.
This occurs in the presence of
patent foramen oval.

15. B- Arterial thrombosis
• Thrombosis of an artery due to
atheroma.
• Thrombosed aneurysm.
• Thrombosis of a reconstructed artery
or bypass graft.
• Popliteal entrapment syndrome &
Cystic adventitial disease.

16. Predisposing factors:
Hypotension.
Dehydration.
Congestive H.F.
Polycythemia.
Hypercoagulable states.
The condition is less severe than embolic occlusion
because there are extensive collateral pathways.
So that the extremity may remain viable for several
days.
Arterial thrombosis cont.

17. C- Acute occlusion of vascular
graft:
The diagnosis is suspected from
history of graft placement and the
visible surgical scars.
The onset is sudden.
This needs immediate intervention.

18. D- Arterial trauma
Penetrating.
Blunt.
Iatrogenic.
 Suspected from history of trauma, or
catheterization.
 Needs immediate surgical
intervention to restore arterial flow
before irreversible ischaemic injury.

19. Athero-embolism ??
Is embolization of a portion of
atherosclerotic plaque from a large
proximal arterial ulcer.
Distal arterial occlusion is composed
of atheroma rather than organized
embolus or large blood clot.

20. Clinical picture of acute
ischaemia
 Pain: Sever ,constant, and aggravated by
movement.
 Pallor( early) mottling (late), superficial skin
necrosis and gangrene.
 Parasthesia: due to ischaemia of peripheral
nerves.
 Paralysis: complete foot paralysis and foot
drop.
 Pulselessness.
 Poikilothermia (progressive coldness).

21. Diagnostic Evaluation
–“Rutherford Criteria”:-
•Class I: Viable
–Pain, No paralysis or sensory loss
•Class 2: Threatened but salvageable
•2A: some sensory loss, No paralysis >No
immediate threat
•2B: Sensory and Motor loss > needs
immediate treatment
•Class 3: Non-viable
–Profound neurologic deficit, absent capillary
flow, skin marbling, absent arterial& venous
signals.

22. Prognosis of acute
ischaemia
Emergency operations in high risk
patients usually associated with 20%
mortality.
Endovascular approaches may lower
peri-procedural mortality and preserve
outcomes.

23. Thrombotic versus embolic
acute ischaemia
Embolic
Thrombotic
•Cardiac events
•Acute onset
•H/o of emboli
•Claudication, PVD
•Bypass graft
•Gradual onset
History
•Normal
contralateral exam
• A.F
•Hair loss, shiny
skin
•Bi-lateral Disease
Physical
•Meniscus Cut-off in
normal vessel
•Bifurcations
affected
•Diffuse disease
•Mid vessel
occlusion
Angiographic

24. Investigations

25.  Investigations
1- Doppler ultrasonography
- Can provide useful information about:
 Degree of ischaemia.
 The probable site of arterial
occlusion.
 The presence of contralateral
atherosclerotic disease.

26. 2- Duplex study
- Can localize the site of occlusion:
 Common femoral artery.
 Superficial femoral artery.
 Popliteal artery.
 But can not distinguish between embolus
or thrombus.
 Can diagnose thrombosed femoral or
Popliteal aneurysm which might not be
obvious on physical examination.


27. 3- Abdominal ultrasonography
 Can rule out the presence of infra-
renal abdominal aortic aneurysm or
iliac artery aneurysm.

28. 4- Angiography
 Can distinguish between embolus and
thrombus.
 Provide a road map for surgical intervention.
 Indicated in suspected arterial thrombosis
and in patients with viable limbs.
 Contraindicated in patients with threatened
limbs, such those with decreased sensory
and motor functions.

31. 5- Echocardiography
 Trans-thoracic echo (TTE) is done first, if no
abnormality is noted ,it should be followed
by trans-osophageal echo (TEE).
 TEE is more accurate :-
 Can detect RT and LT Atrial thrombi.
 Can identify pedunculated mural thrombus
in the descending thoracic aorta which can
not be seen well with angiography.

32. 6- Chest X ray
 To evaluate the presence of
cardiomegaly or LT ventricular aneurysm.
7- E.C.G
 May document the presence of cardiac
dys-rhythmias especially AF and is useful
to rule out myocardial infarction or
ischaemia.

33. 8- Laboratory investigations
 Increase in haemoglobin, blood urea
nitrogen, and creatinine due to fluid
sequestration in the limb and intravascular
hypovolemia.
 Increase in creatinine phosphokinaze ,an
elevation in WBC,and systemic acidosis due
to extensive muscle necrosis.
 Thrombocytopenia due to disseminated
intravascular coagulation.

34. Treatment
of acute ischaemia

35. Treatment of acute ischaemia
•Early recognition and anti-coagulation
–Minimises distal propagation and recurrent
emboli.
•Modalities of Treatment depends on:
–Presumed aetiology.
–Location / morphology of lesion.
–Viability of extremity.
–Physiologic state of patient.
–Available vein conduit for bypass grafting.

36. General measures
1. Oxygen should be administered.
2. IV access and fluids to achieve adequate
hydration.
3. Heparin therapy: a bolus of 5000 units IV
followed by infusion at a rate of 1000 units /
hour.
4. Adequate analgesia.
5. Urine output should be monitored .

37. Treatment Options
•Multiple options are available:-
1 –Conventional surgery.
•embolectomy.
•endarterectomy.
•revascularization.
2- Amputation.
3 –Thrombolytic therapy.
4 –Percutaneous mechanical thrombectomy.

38. Therapeutic Options
–Class 1 or 2A
•Anti-coagulation, angiography and
elective revascularzation.
–Class 2B
•Early angiographic evaluation and
intervention.
•Exception: suspected common femoral
emboli.
–Class3 •Amputation.

40. 1- Embolectomy
 Immediate or delayed according to the
degree of ischemia at presentation.
 Using fogarty Embolectomy catheters.
 Done under local anesthesia with mild
sedation.
 Vertical incision is done over the first
absent pulse.
 Prophylactic fasciotomy is done in
prolonged ischemia.

41. Popliteal embolectomy
–49% success rate from femoral approach.
–Blind passage selects peroneal90%.
–may expose tibial-peroneal trunk & guide
catheter.
–directly cannulate distal vessels.

42. Distal embolectomy
–Retrograde/antegrade via ankle incisions.
–Frequent rethrombosis.
–Thrombolytic treatment is viable
alternative.
Completion angiography:-
–35% incidence of retained thrombus.
•Failure requires:-
–Thrombolytic thearpy.
–Revascularization.

43. 2- Thrombectomy
 Thrombectomy alone is rarely
effective.
 So angiography must be done
before the operation to define
the cause and predict the type of
revascularization procedure.
 Thrombectomy with bypass graft or
thrombo-endarterectomy.
 Under general anesthesia.

44. 3- Thrombolytic Therapy
Advantages
•Opens collaterals & microcirculation.
•Avoids sudden reperfusion.
•Reveals underlying stenosis amenable for
angioplasty.
•Prevent endothelial damage from balloons.
Risks
•Hemmorhage.
•Stroke.
•Renal failure.
•Distal emboli transiently worsen ischemia.

45.  Intra-arterial thrombolysis is a viable
alternative to surgery in limbs with mild
ischaemia, Category 1-2a limbs should be
considered especially in:
 Patients with concomitant
cardiopulmonary disease.
 Patients with thrombosed bypass graft.
 Patients with extensive underlying
atherosclerotic disease who would not
be amenable to simple
revascularization.
 Patients with distal tibial vessel
thrombosis.

46. Thrombolytic therapy cont.
Urokinase is usually given intra-arterially into
the thrombus at a dose of 4000 units /minute
for the first 4 hours and then at 1000-2000
units /minute for up to a total of 48 hours.
Heparin is also given simultaneously at 500-
1000 units /hour to reduce risk of thrombus
formation around the catheter.
Thrombolytic therapy leads to successful
lysis in 60-70 % of patients and limb salvage
in over 80% ,however it is associated with
mortality in 2-5% and major bleeding
requiring transfusion in 4% of patients with
additional 15% rate of lesser complications.

47. TPA
Low dose: 1mg bolus then 0.5 to 1 mg / for 10-12
hours.
High dose: Three 5 mg bolus of TpA are given
over 30 minutes:-
If no angiographic improvement lysis abndoned
If after 30 minutes some dissolution of thrombus:
infusion of 3.5 mg of TpA / hour for next 4 hours
Dose reduced to 0.5-1 mg/hour.

48. Contraindications to thrombolytic therapy

49. A, Distal end of Fountain Infusion Catheter which has
multiple side holes B, Proximal end of the Fountain
Catheter.

50. 4-Mechanical Thrombectomy
•Percutaneous aspiration embolectomy:-
–Viable alternative in selected patients.
–Varity of devises.
–Combines diagnostic and therapeutic procedure.
–Removes non-lysable debris.
–Effective in distal vessels.
–Risk distal embolization.
- Combine with lytic therapy.

51. Thrombectomy devices

52. Thrombolysis - Angiojet
Approved for the direct removal
of blood clots from arterial vessels by
means of catheter techniques.

53. Al-Azhar University
Hospitals- Surgical
dep. Vascular Unit --
Thrombolysis - Angiojet

54. A, Acute left iliac occlusion. B, Trellis balloon C, Complete
thrombus resolution.

55. Complications of vascular repair
- lmmediate postoperative:
1-Thrombosis of repaired vessels .
2- Reperfusion injury .
Early postoperative: .
1-Venous thrombosis.
2-lnfection in the area of vascular reconstruction.
3-Disruption of suture line and hemorrhage.
Late complications: .
1- Aneurysmal changes in the vein graft use.
2- Chronic venous insufficiency after venous thrombosis
or ligation.

56. •Ischaemic-reperfusion syndrome:-
–Local: endothelial damage, capillary permeability,
Transudative swelling, cellular damage.
•Compartment Syndrome.
•Treatment: Fasciotomy.
–Systemic: Lactic Acidosis, Hyperkalemia, Myoglobin,
Inflammatory Cytokines
•Cardiopulmonary complications.
–Renal Tubular necrosis
•Myoglobin precipitates.
•Treatment: Volume replacement, Urinary alklinization,
manitol and Heamodialysis.
Reperfusion Syndrome

57. 5- Amputation
 Is the procedure of choice for :
 Patients with irreversible ischaemia of
any cause.
 Patients who can not tolerate
extensive reconstructive procedures
for limb salvage due to severe illness:
I. ACUTE MYOCARDIAL INFARCTION.
II. Refractory congestive HF.
III. Severe pulmonary insufficiency.

58. Indications for emergency
amputation
 Patients with irreversible ischaemia (severe
rest pain, fixed staining and mottling,
paralysis and profound sensory loss) usually
undergo AKA.
 No attempts should be made to revascularise
these limbs as the reperfusion injury is fatal.
 About 10% of patients present with non
viable limb.
 The amputation rate following acute limb
ischaemia is 25–30%.