Surgery

1. ACUTE LOWER LIMB
ISCHAEMIA
By - K AJAY KIRAN
Roll No – 18-041

2. Definition
• Sudden occlusion of an artery.
• Sudden decrease in limb perfusion that causes a
potential threat to a limb viability
• Mainly Caused by an Embolus
• It may also happens when Thrombosis occurs on an
atherosclerotic plaque.
• Although the outcome is usually less dramatic
because collaterals are likely to have developed in
Chronic arterial stenosis.

3. Aetiology of Acute Lower Limb Ischaemia
I EMBOLISM
• Atrial fibrillation
• Mural thrombosis
• Vegetations
• Proximal aneurysms
• Atherosclerotic plaque

4. II Thrombosis
• Atherosclerosis
• Popliteal aneurysm
• Bypass graft occlusion
• Endovascular stent or stent graft occlusion
• latrogenic (localised arterial dissection post endovascular intervention, e.g. arterial
closure device failure)
• Thrombotic conditions

5. III Rare causes
• Dissection
• Trauma (including iatrogenic)
• Illicit drug use
• External compression
• Popliteal entrapment
• Cystic adventitial disease
• Iliac endofibrosis

6. Embolic occlusion
• An embolus is an object that has become lodged in a vessel
causing obstruction having been carried in the bloodstream
from another site.
• It is often a thrombus that has become detached from the
heart or a proximal vessel.

7. •Sources of emboli include
Left atrium in Atrial fibrillation
Left ventricular mural thrombus following MI
Vegetations on heart valves in infective endocarditis
Thrombi on atherosclerotic plaque
• Emboli may lodge in any vessel and produce
Ischaemia cause Ischaemic symptoms or gangrene and
resulting in Critical Limb Ischaemia

8. Clinical outcome after Acute Lower Limb Ischaemia

9. Clinical Features
• Embolic arterial occlusion is an emergency that requires
immediate treatment
• Ischaemia between 6-12 hours is partly reversible but
beyond 12 hours is usually irreversible and results in
limb loss
• The limb is cold and the toes cannot be moved, which
contrasts the venous occulsion when muscle function is
not affected.

10. • The sudden dramatic
symptoms in the form of 6Ps
• Pain
• Pallor
• Paralysis
• Loss of Pulsation
• Paraesthesia
• Poikilothermia

11. • The diagnosis can be made clinically in a patient who
has no history of intermittent claudication and has a
source of emboli.
• Suddenly develops severe pain – unbearable, burning
and bursting type.
• Limb becomes pale – cold and mottled
• Movement becomes progressively more difficult and
sensation is lost and followed by total paralysis.

12. • Pulses are absent distally but the femoral pulse may be palpable ,
characteristically peripheral pulses below the level of embolism are
not palpable.
• Numbness of the limb – Paraesthesia – If untreated, necrosis of the
muscles followed by gangrene of the limb can occur within a few
hours i.e., 6-24 hours

13. Thrombosis
• Thrombosis is the of formation of solid mass in circulation from
the constituents of flowing blood, the mass itself is called a
thrombus.
• Thrombi can lodge in a blood vessel and block the flow of blood.
• Depriving the tissues of normal blood flow nad oxygen,
• Resulting in damage and destruction or even death of the tissue.

14. Arterial Trauma
• Also causes acute limb Ischaemia.
• The causes are
- Pressure on a major artery by an angulated bone.
- Intimal rupture of a major artery due to fracture or
dislocation.
- Injury to a major artery by a bone fragment.
- Supracondylar fracture of femur.
- Dislocated knee.

15. INVESTIGATIONS
• Acute limb Ischaemia is a surgical
emergency and the diagnosis is usually clear
from History and Examination.

16. •Blood examination -
Hb, RBC count, WBC count, ESR, CRP, Platelet count,
FBS , HbA1c
Lipid Profile – Total cholesterol HDL, LDL and
Triglycerides.
Serum – Lactate, Urea, creatinine, and electolytes.
• ECG and Echocardiogram
• Chest X ray

17. Duplex Ultrasound
• Non invasive technique uses – Doppler with B mode ultrasound to
provide an image of vessels.
• Locate anatomical lesion and degree of stenosis.
• Arterial waveforms assessed to detect the degree of stenosis or
occlusion.
• Normal elastic arteries – Triphasic waveforms
• Lesion of moderate stenosis (50% reduction ) – Biphasic
waveforms
• More than 70% stenosis – Monophasic waveforms.
Imaging Modalities

18. • It allows both the visualisation of vessels and detailed
assessment of waveforms and blood flow.
• Change in the peak systolic velocity (PSV) – indicate the
degree of stenosis.
• PSV is measured in the normal artery proximal to stenosis
and then within the stenosis.

19. • Combination of PSV, waveform assessment and visualisation of
the artery provides useful information on the severity of stenosis.
• Accurate, cost effective and safe
• Aortoiliac segment can be difficult to visualize particularly in
obese patients – CT angiogram useful.

20. Digital Subtraction Angiography
• Standard investigation for Acute Limb Ischaemia.
• Image is digitalised by computer and background ( bone, soft
tissues ) removed to provide clear images.
• It should be chosen in such a way that both inflow and outflow
can be evaluated.
• Intra-arterial vasodilators can be used to reduce vasospasm in
the vessels distal to the site of occlusion, and thus enhance
visualisation of the distal arterial bed.
• Patients with severe renal insufficiency, carbon dioxide
angiography may be considered

21. CT & MR Angiography –
• Useful where duplex ultrasound is not possible (intrathoracic arteries) or
produces poor image (Aortoiliac segment).
• MR has the added advantage of avoiding the need for ionizing radiation and
iodinated contrast .
• MRA now the first line investigation for PVD.

22. Staging of Acute Lower Limb Ischaemia

23. TREATMENT

24. Goals of Treatment
• Restoration of blood flow
• Preservation of limb and life
• Prevention of recurrent thrombosis

25. Approach to Acute Lower Limb Ischaemia

27. • -> Immediate administration of 5000 U of HEPARIN IV can
reduce the extension and maintain patency of surrounding
vessels until the embolus can be treated.
• -> Opioid analgesic for the relief of pain is essential
because it is severe and constant.
• Embolectomy and Thrombolysis are the available
treatments.

28. EMBOLECTOMY
• Local or GA may be used
• The artery, bulging with clot , is exposed and held in
silastic vessel loops.
• Through a transverse incision the clot begins to extrude
and is removed, together with the embolus, with help of a
FOGARTY Balloon catheter.

29. • The Catheter with its balloon tip, is introduced both
proximally and distally until is deemed to have passed the
limit of the clot.
• Balloon is inflated and catheter withdrawn slowly together
with obstructing material.
• Procedure repeated until bleeding occurs

30. • Angiogram is performed in the operating theatre at end of
procedure to ensure that flow to the distal legs has been
restored.
• Postoperavtively , HEPARIN therapy is continued until
long term anticoagulantion with warfarin is established to
reduce the chance of further embolism

31. A A Fogarty catheter is inserted through an arteriotomy in the common femoral
artery and fed distally down the superf icial femoral artery and through the
embolus.
B The balloon is inflated and the catheter withdrawn, removing the embolus;
the deep femoral and iliac arteries are similarly treated.

33. THROMBOLYSIS
• At the arteriography of Ischaemic limb a narrow catheter is
passed into the occluded vessel and left embedded within
the clot
• Tissue Plasminogen Activator is infused through the
catheter and regular arteriogram are carried out to check
the extent of lysis . In succesful cases it is achieved within
24 hours
• Method should abandoned if there is no progression of
dissolution of clot with time.

34. Slow infusion
• Streptokinase 5000 units/hour
• Tissue plasminogen activator (t-PA) 0.5 mg/hour
• Urokinase 4000 IU/min for 2 hours, then 2000 IU/min for 2 hours, then
1000 IU/min
Pulsed spray
• t-PA 0.3 mg per pulse every 30 seconds
• Urokinase 5000 IU per pulse every 30 seconds
High-dose bolus
• t-PA 5-mg bolus every 10min three times, then 3.5mg/hour for up to 4
hours, then (if required) as for slow infusion
Suggested drug regimens for thrombolysis

35. A-Before thrombolysis
B-During successful lysis
ANGIOGRAM OF AN
OCCLUDED
POPLITEAL ARTERY

36. Contraindications to THROMBOLYSIS
• Active internal bleeding
• Pregnancy
• Stroke within 2 months
• Transient ischaemic attack within 2 months
• Known intracerebral tumour, aneurysm or arteriovenous
malformation
• Severe bleeding tendency

37. • Craniotomy within 2 months
• Vascular surgery within 2 weeks
• Abdominal surgery within 2 weeks
• Puncture of a non-compressible vessel or biopsy within 10 days
• Previous gastrointestinal haemorrhage
• Trauma within 10 days

38. Compartment Syndrome
• Limbs that have been subject to sudden ischaemia followed
by revascularisation, oedema is likely.
• Muscles swell within confined fascial compartments and this
can itself be a cause of tissue ischaemia,
• Both local muscle necrosis and nerve damage due to
pressure, and systemic effects such as renal failure
secondary to the liberation of muscle breakdown products.

39. • Liberal concomitant usage of fasciotomy following
revascularisation of a prolonged ischaemic limb is advis
able.
• Classical clinical picture is of severe pain out of proportion
with clinical findings worsens with time, despite appropriate
analgesia.

40. • Patient often complains of numbness/paraesthesia.
• On examination limb reveals a tense compartment with
passive flexion and extension of muscles causing pain.
• Treatment is urgent compartment fasciotomy to release the
compression.

41. ANGIOPLASTY
• Percutaneous transluminal angioplasty is
indicated in short stenotic lesions in large vessels
– in iliac and femoropopliteal lesions
• The ballon catheter is introduced percutaneously
over a guidewire across the lesion.

42. • Under fluoroscopic control, the balloon is dilated until
satisfactory widening of the lumen is achieved
• This procedure is relatively safe and simple.
• Immediate IV infusion of HEPARIN – 10000 IU is necessary
to reduce the extension of the thromboembolism

43. Summary of Management

44. Source
• Bailey and Love’s – Short Practice of Surgery
• European Society for Vascular Surgery (ESVS) 2020
Clinical Practice Guidelines on the Management of Acute Limb Ischaemia
• Manipal Manual of Surgery
• S Das – Clinical Surgery

45. Thank You