Shunts

Abstract

Of the 50,000 patients with end-stage renal failure in Germany, each year some 15,000 become candidates for creation of a hemodialysis access. A native arteriovenous (AV) fistula has a better prognosis with longer patency and fewer complications such as infections and is therefore preferred to the creation of a dialysis fistula with use of a synthetic implant (Tordoir et al. 2007). An advantage of a synthetic shunt is that it can be used earlier, while a native fistula needs time to mature before it can be used for hemodialysis access. A synthetic shunt is the second option in patients whose native vein (typically the cephalic vein) is deemed unsuitable because of a small lumen or because it has undergone thrombotic or fibrotic degeneration as a result of frequent puncture. A minimum flow volume is necessary to ensure adequate dialysis treatment. Protocols in the USA require a flow volume of at least 350 mL/min, while some European countries accept smaller volumes, for example, 200–300 mL/min in Germany. This requirement informs the preoperative search for a shunt vein or makes use of a synthetic loop necessary. Preoperative vascular mapping contributes important information for selecting the most suitable hemodialysis access for each patient.