Vascular Surgery
Vascular Surgery tests the ischaemia-aneurysm-venous triad plus vascular access. The exam wants a bedside examination translated into an urgency category and a definitive plan.
Chronic limb ischaemia
- ABPI: 0.9-1.3 normal; 0.5-0.9 claudication; below 0.4 rest pain or tissue loss. In diabetes and renal failure medial calcinosis makes arteries incompressible and the ABPI falsely high (>1.3) - use toe pressure or toe-brachial index.
- Claudication: supervised exercise, smoking cessation, statin and antiplatelet therapy; revascularisation for lifestyle-limiting symptoms that fail conservative care.
- Chronic limb-threatening ischaemia (rest pain, ulceration, gangrene) needs urgent CT or MR angiography and revascularisation; a vein bypass is the most durable option for long femoropopliteal disease.
Acute limb ischaemia
The six Ps: pain, pallor, pulselessness, paraesthesia, paralysis and perishing cold. Start therapeutic heparin immediately, image if the limb is viable, and operate for embolectomy if threatened. Sensory or motor deficit means threatened, and delay costs the limb.
Aneurysm and carotid
- AAA: elective repair at 5.5 cm in men (5.0 cm in women) or growth above 1 cm/year; EVAR has lower early mortality but requires lifelong surveillance.
- Symptomatic 70-99% carotid stenosis (NASCET): endarterectomy ideally within 14 days of the index TIA or amaurosis fugax, on best medical therapy.
Venous, lymphatic and access
Venous ulceration: compression bandaging after checking the ABPI, plus correction of superficial reflux. A radiocephalic arteriovenous fistula is the preferred first access, assessed by the rule of 6s: flow above 600 mL/min, diameter above 6 mm, depth under 6 mm, matured by 6 weeks.
Worked example
A 72-year-old diabetic with a 6-week-old heel ulcer has an ABPI of 1.4. That value is uninterpretable because of calcinosis; a toe pressure of 30 mmHg confirms limb-threatening ischaemia, so angiography and vein bypass are planned.
Traps
Trusting a high ABPI in a diabetic; giving heparin after rather than before imaging in acute ischaemia; applying compression with an ABPI below 0.8.