What investigations are recommended for a patient presenting with acute limb ischemia before considering vascular surgery?

Recommended investigations for a patient presenting with acute limb ischaemia before considering vascular surgery include:

• Clinical assessment including history of symptoms and physical examination of the legs and feet, focusing on signs of critical limb ischaemia such as ulceration and pulse examination (femoral, popliteal, and foot pulses) ¹.
• Measurement of the ankle brachial pressure index (ABPI) using a Doppler probe to assess arterial blood flow, ideally with the patient resting and supine ¹.
• Duplex ultrasound as the first-line imaging modality to evaluate the arterial anatomy and blood flow for planning revascularisation ¹.
• If further imaging is required after duplex ultrasound, contrast-enhanced magnetic resonance angiography (MRA) should be offered to delineate the vascular anatomy more precisely ¹.
• If MRA is contraindicated or not tolerated, computed tomography angiography (CTA) is the alternative imaging option ¹.

These investigations help confirm the diagnosis, assess the severity and extent of arterial occlusion, and guide the suitability and planning of vascular surgery or other revascularisation procedures.