Do central venous catheters have advantages over arteriovenous fistulas or grafts?

Abstract

Central venous accesses have become an integral component of vascular access procedures for hemodialysis. Although the DOQI guidelines recommend that less than 10% of chronic hemodialysis patients should be maintained on catheters, in some countries higher prevalences are reported, as in the United States and the United Kingdom (18% and 24%, respectively, according to the DOPPS). The native arteriovenous fistulas are still the best suited accesses for hemodialysis. However, this option is impractical in many situations, so that several justifiable reasons exist for protracted dialysis catheter use; these include the catheter as a bridge angioaccess device, while the patient is awaiting living-related kidney donor transplantation or maturation of an autologous fistula or graft or, increasingly, as the permanent vascular access for patients with unsuitable vascular anatomy who have exhausted all other options. Moreover, the surgical creation of an AVF is felt to be impossible or at least seems to entail significant risks in situations of high output cardiac failure, myocardial ischaemic events and steal syndrome. In these cases, the dialysis access catheter brings considerable advantages, but it also carries tremendous drawbacks. In addition to the increased risk of luminal thrombosis, infection, unreliable blood flows, central venous stenosis, shorter use life and patient cosmetic concern, tunneled catheters are associated with an increased risk of death. Tunnellization, exit site protection, antibiotic-coated or antiseptic-impregnated hemodialysis catheters, antibiotic lock solutions could be helpful in preventing and treating catheter-related bacteremias. Moreover, the development of a subcutaneous port, that is durable, offers a high blood flow and is fully implantable subcutaneously, may become an alternative for chronic use. In our 10-year experience we implanted in our center over 450 central venous catheters with a satisfactory survival (86% at 1 year and 79% at 2 years for the subcutaneous port). In a matched comparison between Tesio twin catheters and Dialock ports (37 vs. 35, respectively), followed for a 2 year period, no significant differences emerged as regards bacteremia incidence, 0.58/1,000 catheter-days in the Tesio catheter group vs. 0.9/1000 catheter-days in the subcutaneous port group, p=0.12; thrombolytic agents needed, 4.5% vs 4.3% of dialysis sessions; or access failure with removal of the device, 8.1% vs 14.2%, p=0.4. The longer duration of antibiotic therapy in the Tesio group (24.6 vs 14.3 days, p=0.006) was due to the higher incidence of cutaneous infectious episodes (3.8 vs 0.16/1,000 catheter-days). In conclusion, although central venous catheter is the vascular access of last choice, in particular cases it can be a useful alternative, provided that strict protocols for nursing care and proper catheter management are implemented in every center.