Haemodialysis

Delivery of haemodialysis is dependent on having a vascular access that can reproducibly deliver an adequate blood flow thrice weekly. None of the three types of vascular access is perfect; each has potential advantages and drawbacks. Fistulas are the preferred type of vascular access because they have the longest cumulative survival and require the fewest interventions to maintain their long-term patency, once they achieve suitability for dialysis. However, fistulas have a fairly high non-maturation rate, frequently require revisions to achieve suitability for dialysis, and often are associated with prolonged catheter dependence until they are ready to cannulate. In contrast, grafts have a lower primary failure rate, are usually ready to use within 2–3 weeks of creation, and are therefore associated with a shorter duration of catheter dependence. However, the cumulative survival of grafts is shorter than that of fistulas, and they require more frequent interventions (angioplasty, thrombectomy, or surgical revisions) to maintain their patency for dialysis. The major advantage of dialysis catheters is that they are suitable for use as soon as they are placed. However, catheter use is associated with frequent complications, including catheter-related bacteraemia, dysfunction, and central vein stenosis. Many patients require a tunnelled dialysis catheter as a bridge, until they have a mature fistula or graft. Optimal management of vascular access is extremely challenging, and requires close collaboration among multiple medical disciplines, advance planning, and treatment or prophylaxis of their frequent complications.