In the management of critical limb ischaemia, what is the surgical intervention if there is definitive fixed mottling?

The correct response is primary amputation, which is indicated in cases of definitive fixed mottling in the context of critical limb ischaemia. Fixed mottling suggests irreversible tissue damage and underlying necrosis, meaning that the survival of the limb is compromised. When tissue viability has diminished to this level, attempts to restore blood flow through less invasive procedures such as embolectomy or angioplasty are unlikely to succeed, as they cannot address the extensive tissue injury that has already occurred.

Primary amputation serves to remove the non-viable tissue, preventing further complications such as infection and systemic toxicity. This surgical intervention can also alleviate suffering for the patient by addressing the pain associated with necrotic tissue. Early amputation can be life-saving and can help in better management and rehabilitation overall.

In contrast, while exercise therapy is beneficial for improving circulation in cases of intermittent claudication, it is not appropriate when significant tissue damage has already occurred. Embolectomy and angioplasty might be considered in acute limb ischaemia due to emboli or stenosis, but they are not effective treatments when mottling indicates irreversible ischemia. Thus, primary amputation is the most appropriate management in this scenario.