The evolution and function of central venous catheters for dialysis

The use of central venous catheters (CVC) for acute or chronic dialysis has been a relatively recent innovation in Nephrology. The first problem addressed has been how to allow removal and return of blood at high flow rates throughout a dialysis treatment. Four solutions have emerged: place the lumens within the right atrium; place the removal lumen on the inside of the catheter; use a large catheter size; or provide independent limbs with multiple blood-entry ports to draw and return blood in all directions. Many other requirements include resistance to infection, especially the passage of organisms around the catheter. A subcutaneous Dacron cuff within a tunnel has successfully accomplished this goal for most chronic CVC dialysis catheters, but other immobilizing devices such as plugs have also been successful. Materials for CVC dialysis catheters have improved, providing strength to allow the catheters to last for several years, with flexibility to avoid vein damage (in general). However, component and material failures still occur, and some materials are incompatible with medications placed at the exit site. CVC for dialysis will remain a necessary choice for many patients beginning and continuing dialysis therapy.