Vascular Access, Angiography and Arterial Intervention
This domain covers the technical core of arterial IR: safe access, catheter–wire skills, angiographic interpretation, and choosing between angioplasty, stenting, embolisation and surgery. Items often ask for the next step after a complication or the correct device for a lesion.
Access and basic technique
- Common femoral artery: puncture at the midpoint of the femoral head, below the inguinal ligament and above the bifurcation; ultrasound reduces complications. A high puncture risks retroperitoneal haemorrhage; a low puncture risks pseudoaneurysm and arteriovenous fistula.
- Radial access: confirm dual palmar supply with the Barbeau test; use smaller sheaths; prevent spasm with a vasodilator cocktail.
- Sheath size: 4–6 F for diagnostic work; match to the device. Give heparin 50–100 IU/kg for arterial intervention unless contraindicated.
Angiography and intervention
- Perform a diagnostic run before crossing; document inflow, lesion length and runoff. Use CO₂ or dilute contrast in renal impairment.
- Angioplasty: balloon sized 1:1 to the reference vessel; prolong inflation for dissection. Bailout stenting for flow-limiting dissection or residual stenosis >30%.
- Stent choice: self-expanding nitinol in the superficial femoral artery; avoid rigid stents across flexion points.
- Embolisation: coils for focal arterial bleeding, particles for tumour, gelatin sponge for temporary occlusion.
Worked example
A 68-year-old with tissue loss has a 12 cm superficial femoral artery occlusion and single-vessel runoff. Reasoning: obtain antegrade or crossover access; cross with a hydrophilic wire and support catheter; predilate; deploy a self-expanding stent; confirm runoff and treat any tibial stenosis. Do not stent a long occlusion without checking the distal landing zone.
Traps
Puncturing above the inguinal ligament; failing to give heparin; oversizing balloons; ignoring runoff disease; missing popliteal entrapment or cystic adventitial disease.