Diagnosis

Chronic limb ischemia

Etiology

Cause [s2g]

1. Lower extremity

   • Atherosclerosis and stenosis (95%)

   • Other: vasculitis, hereditary conditions, undiagnosed past embolism or local thrombosis, lower limb aneurysms, trauma, popliteal entrapment, or cystic adventitial disease

2. Upper extremity:

   • Vasospasm, arteritis, subclavian steal syndrome

Pathophysiology [s2g]

1. Atherosclerotic plaque builds up slowly --> arteries compensate by dilating --> eventual stenosis of the arterial flow lumen --> gradual ischemia

   • Significant stenosis: 50% decrease in vessel diameter

   • Supply-demand mismatch --> ischemia of the muscles --> pain, cramping

   • Collateral flow --> blood flow shifts to smaller arteries --> preserves distal perfusion

2. Emboli of cardiac origin or from atherosclerotic aorta --> sudden ischemia

3. Plaque rupture: unstable atherosclrotic plaque break off or "rupture" --> sudden ischemia

Risk factors [s2g][dhb][6zo]

• Diabetes mellitus

• Smoking

• Obesity (BMI > 30)

• Hypertension

• Hypoercholesterolemia

• Increasing age

• Family history of atherosclerosis, heart disease or stroke

• Homocysteinemia

Complications [s2g]

• Ischemia/Gangrene

• Amputation

• Infection

• Ulceration

• Heart attack

• Stroke

• Blood clots

• Erectile Dysfunction

Epidemiology

Prevalence per 100.000

Incidence per 100.000

Approach

• Pulse examination: Carotid, brachial, radial, ulnar, abdominal, femoral, popliteal, posterior tibial, dorsalis pedis pulses. 

• Ankle-brachial index (ABI): ≤ 0.9 is a solid marker of atherosclerosis

• Toe pressure (TP) and toe-brachial index (TBI)

• Treadmill testing

• Femoral-brachial pressure ratio

• Medical imaging: Duplex ultrasound (DUS), CT angiography, MR angiography, Digital subtraction angiography (DSA)

Treatment

1. Risk factor management: [dhb]

   • Lifestyle: Smoking cessation, weight loss, metabolic syndrome, and diabetes. 

   • Antithrombotic therapy

   • Lipid lowering agents

   • Antihypertensive agents

   • Antidiabetic agents (GLP-1 receptor agonist, SGLT-2 inhibitors)

2. Invasive management: [dhb]

   • Aorto-iliac segment:

     • Endovascular balloon angioplasty with selective stent placement.

     • Hybrid or surgical anatomical revascularisation

     • Femorofemoral crossover bypass grafting

   • Common femoral artery including the femoral bifurcation:

     • Primarily open surgery with endarterectomy.

   • Common femoral artery:

     • Endovascular balloon angioplasty may be considered.

   • Femoropopliteal segment:

     • Endovascular paclitaxel coated balloon angioplasty, selective drug eluting stent placement, and covered stents

     • Open surgical femoropopliteal bypasses with autologous vein or prosthetic materials

   • Bellow the knee:

     • Endovascular balloon angioplasty

     • Open bypass grafting with a venous graft may be considered if exhaustive non-invasive treatment and endovascular therapy is not an alternative option

Differential diagnoses

Aortic dissection, Deep venous thrombosis, Raynaud phenomenon, Spinal disc herniation, Spinal stenosis, Thromboangiitis obliterans, Thrombophlebitis