Vascular Surgery — Recognising Chronic Limb-Threatening Ischaemia
A 71-year-old man who smokes and has hypertension and type 2 diabetes is seen in the vascular clinic. The right popliteal and foot pulses are diminished. There is a healed scar from a previous left popliteal bypass. Which finding would indicate that his right leg is now at risk of limb loss?
- A.Calf pain on walking 150 metres, relieved by rest
- B.Burning forefoot pain at night, relieved by hanging the leg downCorrect
- C.Previous bypass surgery on the contralateral leg
- D.Hair loss and shiny atrophic skin over the shin
Explanation
Pain in the forefoot at rest, typically worse at night when the leg is elevated in bed and eased by hanging the foot over the edge, means perfusion no longer meets even basal tissue needs. Together with ischaemic ulceration or gangrene, ischaemic rest pain defines chronic limb-threatening ischaemia, the stage at which amputation risk is high without revascularisation. The 2019 Global Vascular Guidelines therefore treat it as an indication for urgent vascular imaging and revascularisation planning. Intermittent claudication is the main competitor because it is also a symptom of ischaemia, but it reflects adequate flow at rest with insufficient reserve on exertion; most patients with claudication remain stable on risk-factor control, antiplatelet therapy and supervised exercise, and fewer than 5 percent progress to amputation over 5 years. A previous bypass on the other leg shows that his disease is extensive and recurrent but says nothing about the current state of the right limb. Hair loss and shiny skin are trophic signs of longstanding peripheral arterial disease, not of threatened tissue. Diabetic neuropathy can mask rest pain, so ulcers or gangrene may be the first sign.
Why each option
- A.
- Claudication indicates adequate resting perfusion with limited exercise reserve, and most patients remain stable without limb loss.
- B.
- Correct. Ischaemic rest pain eased by dependency means resting perfusion is inadequate, defining chronic limb-threatening ischaemia needing revascularisation.
- C.
- Contralateral bypass shows extensive atherosclerotic disease but does not describe the current perfusion of the symptomatic right leg.
- D.
- Trophic skin and hair changes reflect longstanding arterial insufficiency but do not by themselves signal imminent tissue loss.
Reference: Global Vascular Guidelines on the Management of Chronic Limb-Threatening Ischemia (Conte et al., J Vasc Surg 2019); ESC 2024 Guidelines for Peripheral Arterial and Aortic Diseases
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