Acute limb ischemia

by PROF/ GOUDA ELLABBAN

EGYPT

Definition

• Ischemia is deficiency of blood supply in a part of the body.• It could be acute chronic • Acute limb ischemiaSudden interruption of arterial blood supply the with no time for collaterl to form .

Causes of acute arterial ischemia

• An arterial embolus• Thrombosis on an atheromatous plaque• Thrombosis of an aneurysm • Arterial dissection • Traumatic disruption • External compression e.g cervical rib , popliteal

entrapment

Arterial embolus• Abnormal undissloved material carried in the blood stream from one part of vascular system to impact in distance part .

• Types 1-Thrombus It is the thrombus that dislodged from its source & circulate in blood stream & impact in BV 2-Air 3-Fat 4-Neoplastic

• Common source is mural thrombus that follow MI, mitral stenosis & aneurysm • Emboli tend to lodge at bifurcation of vessles• Large emboli stradding in oartic bifurcation Lower limb ischemia

Trauma

Could be 1. Penterating 2. Blunt

3. Iatrogenic Commonly in femoral or brachial artery

at arterial catheterization

Symptoms and Signs ( Ps )• SymptomsPainless ( numbness )PainParaesthesiae Paralysis

• SignsPallor Pulslessness Perishingly cold to the touch

* Muscle tenderness is bad diagnostic especially in muscle of anterior & posterior compartment of the calf

Physical Examination• Heart rhythm:

• Presence of atrial fibrillation or other arrhythmias

• Apex beat (ventricular aneurysm)• Auscultation for evidence of valvular disease

• Inspection of limbs:• Pallor of the skin

• Tense, tender calf with impaired dorsiflexion (compartment compression)

Physical Examination• Venous guttering:

• Veins are so empty to appear as shallow grooves or gutters

• Buerger’s test: rapid pallor as arterial supply is poor.

• Delayed capillary refill. • Skin temperature: a difference of as small as 1˚C

can be ascertained.

Physical Examination• Absent peripheral pulses:

• Important to delinate a blockage in the arteries (e.g. presence of femoral pulse and absent distal pulses indicate superficial femoral block.

• Ankle brachial pressure index (ABPI)• It is the ratio of pressure at foot pulse to that at

the brachial artery. < 0.5 indicate significant ischemia.

complication

• Leg become mottled & marbled

• Muscle hardness

• Skin become blister

• Gangrene which usually start in toes before spreading distally

Differential Diagnosis

• Arterial embolus • Acute arterial thrombosis • Thrombosed aneurysm • Aortic dissection• Traumatic arterial disruption • Cervial rib• Acute venous thrombosis• Spinal cord compression or infarction

Investigation • Critical ischemia needs investigating with great

urgency to relieve the patient’s pain and to prevent irreversible damage.

• They include:• Arteriography• Duplex ultrasonography: it is now replacing

angiography. It takes longer time to perform and is more subjective but can give better information as to the significance of stenoses and has the benefit of being non-invasive.

• ECG to exclude associated coronary diseases• Serum cholesterol: raised in atherosclerosis• Urine for sugar and blood glucose: to exclude DM

Management • Non-operative:

• Arteriography and angioplasty: at the time of arteriography, a stenosed segment of artery may be dilated using a special balloon catheter.

• Lumbar sympathectomy: palliationmay be achieved by lumbar sympathectomy which increases the blood supply to the skin, and which may be performed percutaneously. The small increase in blood supply may be sufficient to allow an ulcer to heal but will not generally improve rest pain.

Management• Operative treatment:

• Reconstructive surgery: successful surgical reconstruction demands 4 things:

• Inflow: a good arterial supply up to the area of blockage is necessary to ensure that blood can be carried distally via the conduit to ischemic area

• Outflow: there should be good vessels below the area of disease on to which a conduit can be anastomosed.

• The conduit: a graft of saphenous vein or an inert prosthetic material may be used.

• The patient: critical ischemia is often the first sign of end-stage vascular disease which inevitably result in death. Surgery for critical ischemia has a high mortality reflecting this general deterioration.

Management• The conduit:

• A graft of saphenous vein, reversed or used in situ with valve destruction, or an inert prosthetic material such as polytetrafluoroethylene (PTFE) may be used for the conduit to take blood from proximal to distal segment of the artery beyond the blockage. In graft that start and finish above the knee there is little to choose between PTFE and vein in terms of long-term patency, but a graft that crosses the knee is much more likely to remain patent if it is saphenous vein rather than PTFE. Infection is less likely with autologous vein.

Management• Operative treatment:

• Amputation: • Pain that is not controlled by sympathectomy

or reconstructive surgery, and gangrene that is associated with life-threatening infection are indications for amputation of the limb or part of the limb. The general principle is to achieve a viable stump that heals primarily, and a secondary goal is to make the stump as distal as possible.