Vascular access for haemodialysis
๐ฉธ Introduction
- ๐ Vascular access is essential for haemodialysis.
- ๐ Options: dual-lumen central venous catheters (acute use) OR arteriovenous (AV) fistula/graft (chronic use).
- ๐ Dual-lumen catheters (internal jugular > femoral > subclavian): immediate access but ๐จ higher infection/thrombosis risk.
- ๐ Tunnelled lines: long-term use if fistula not possible (e.g. poor vasculature, comorbidity).
- โญ AV fistula = gold standard: artery โ vein anastomosis โ high-flow, durable access. Takes 4โ6 weeks to mature.
- ๐๏ธ First choice = radiocephalic fistula (non-dominant wrist). Other options:
- ๐ช Brachiocephalic fistula (elbow)
- ๐ Brachiobasilic fistula (with transposition)
- ๐งช Synthetic graft (ePTFE) if native vessels unsuitable
โ ๏ธ Complications
- โฑ๏ธ Immediate: bleeding, haematoma, arterial puncture.
- ๐ Early: infection (esp. catheters), thrombosis, failure to mature (โค30%).
- ๐ฐ๏ธ Late:
- ๐๏ธ Steal syndrome: hand ischaemia (pain, pallor, cold, ulcers).
- ๐ Aneurysmal varices: repeated needling โ rupture risk.
- โค๏ธ High-output cardiac failure: rare, high flow shunt.
- ๐ฉต Venous hypertension: limb swelling, congestion.
- ๐ชค Central vein stenosis: esp. post-subclavian lines โ arm swelling.
๐ Fistula Maturity
- โ
Ready after 4โ8 weeks if: good size + high flow.
- โ Clinical: palpable thrill + audible bruit.
- ๐ฅ๏ธ US flow >600 mL/min = ideal.
๐ ๏ธ Clinical Pearls
๐ก Key Pearls:
โญ AV fistula = longest survival, lowest infection.
๐ซ Never use fistula arm for BP, bloods, or IV lines.
๐ซ Avoid subclavian lines (stenosis risk).
๐ Urgently refer access issues to vascular team.
๐ Comparison of Vascular Access Options
๐ Central Venous Catheter (CVC)
โ๏ธ Immediate access, no maturation needed.
โ Infection + thrombosis, poor long-term patency, central stenosis.
โก๏ธ Used for AKI, bridging, or unsuitable for fistula/graft.
๐ Arteriovenous (AV) Fistula
โ๏ธ Best long-term survival, lowest infection, high flow.
โ 4โ8 wks to mature, failure to mature (โค30%), steal syndrome, aneurysm, high-output failure.
โก๏ธ Gold standard for chronic haemodialysis.
๐ AV Graft (Synthetic ePTFE)
โ๏ธ Can use in 2โ3 weeks, option if poor veins.
โ More infection, poorer patency than fistula, frequent re-interventions.
โก๏ธ For patients with poor native vessels (elderly, diabetics).
๐ก Quick Rules
๐ Infection risk: CVC > Graft > Fistula
๐ Patency/survival: Fistula > Graft > CVC
๐ Always confirm thrill + bruit before use