Chronic Limb-Threatening Ischemia

Chronic Limb-Threatening Ischemia (CLTI) — previously called critical limb ischemia (CLI) — is the most severe form of peripheral artery disease (PAD). It's a serious condition that requires prompt attention to avoid limb loss. Same risk factors as peripheral arterial disease.

🦵 What Is CLTI?

CLTI occurs when there is severely reduced blood flow to the limbs (usually the legs) over a long period of time, leading to:

• Rest pain (pain in the foot or toes, even at rest, especially at night). The pain is worse when the lower extremities are elevated. They are alleviated when the lower extremities are dependent.
• Non-healing wounds or ulcers [usually below the ankle]. Delayed or no healing of lower extremity amputations [toe, transmetatarsal,  foot surgeries, below or above the knee].
• Gangrene

This is due to advanced atherosclerosis, where arteries are narrowed or blocked by plaque.

⚠️ Signs & Symptoms

• Ischemic rest pain – burning pain in the toes/forefoot, worse at night
• Ulcers – typically on toes, heels, or pressure points
• Gangrene – black, dead tissue (dry or wet)
• Cold, pale, or bluish foot
• Weak or absent pulses in the foot

🧪 Diagnosis

1. Clinical evaluation – symptoms + physical exam. Most Important.
2. Ankle-Brachial Index (ABI)
• ABI < 0.4 suggests severe ischemia.
• Can also occur with higher ABIs in Diabetics and patients with chronic kidney disease. Therefore, clinical evaluation is the most important.
3. Toe pressures / Transcutaneous oxygen pressure (TcPO₂)
4. Imaging to locate blockages:
• Doppler ultrasound
• CT angiography
• MR angiography
• Digital Subtraction Angiography (DSA) (gold standard)

🛠️ Management Goals

• Limb salvage
• Pain control
• Wound healing
• Prevent amputation

🔄 Revascularization

Essential in most cases:

• Endovascular therapy (angioplasty, stenting) is the first line and preferred therapy, except in a few cases
• Surgical bypass (e.g. femoral-popliteal bypass)
• Decision depends on anatomy, patient health, and extent of disease

💊 Medical Therapy

• Antiplatelets (aspirin, clopidogrel)
• Statins – to manage atherosclerosis
• Xarelto 2.5 mg twice a day
• Blood pressure and diabetes control
• Smoking cessation – critical!

🩹 Wound Care

• Debridement
• Specialized dressings
• Infection control (antibiotics if needed)
• Off-loading [reduce the constant mechanical stress on the wounds or gangrene]

🚫 Complications

• Major limb amputation. Very high risk if revascularization [opening up the blockage or bypass] is not performed.
• Infections (cellulitis, osteomyelitis)
• Sepsis
• Death – high 1-year mortality rate. Secondary to heart attacks and strokes. Hence, aggressive risk factor modification and other interventions to reduce heart attacks and strokes.

🧠 Summary: CLTI Red Flags

“Pain, pallor, pulselessness, paresthesia, paralysis, and poikilothermia”
Though mostly associated with acute ischemia, some may apply in CLTI too.