Venous catheters are the least desirable method of hemodialysis access. In a sense, every placement of a venous catheter represents a failure to prepare a native fistula in advance of initiating dialysis as well as a failure to detect a dysfunctional AV access and to intervene preemptively either to maintain its function or to create a new alternative access. Nevertheless, venous catheters are an unavoidable necessity for many patients who do not have functional AV access. For most interventional nephrologists, insertion of tunneled dialysis catheters is the first and most basic procedure acquired, building on the common skill of temporary hemodialysis catheter placement. Nevertheless, the risks of this procedure should not be understated, with the potential for severe injury to major central vessels from large-bore catheters and dilators. The use of real-time ultrasound guidance is widely considered to be essential for safe and efficient venipuncture based on higher procedural success rates and fewer complications compared to the use of landmarks only. The low posterior approach to the right internal jugular vein is ideal; this keeps the catheter low on the neck, with minimal patient discomfort and a good cosmetic result, and creates a smooth bend of the catheter that avoids kinking. Fluoroscopy is also recommended for proper catheter tip positioning, although there is limited evidence to support this requirement. There is general agreement that the performance of chronic dialysis catheters is optimized when the catheter tips are placed in the right atrium, and Disease Outcomes Quality Initiative (DOQI) guidelines support this approach. Nevertheless, this remains controversial, and achieving the desired tip position is difficult, even with fluoroscopy and careful attention to anatomic landmarks. In any case, to achieve the best possible outcomes, the operator must adhere to a meticulous sterile surgical technique, utilize ultrasound guidance for venipuncture, and pay careful attention to tip positioning using fluoroscopic and/or landmark guidance. Figure 57–1A shows a poorly placed left internal jugular vein tunneled dialysis catheter, with a high vein puncture from the anterior approach, a tight bend with the catheter kinked, and its split tips extending only into the superior vena cava. This catheter did not function for dialysis. Figure 57–1B shows the catheter replaced with a new Ash-Split catheter (Medcomp, Harleysville, PA), using the right internal jugular vein puncture from a low posterior approach with a smooth bend in the neck. In Figure 57–1C, the new catheter tips are shown extending into the high right atrium, yielding excellent catheter function as required for delivery of hemodialysis.
Over the past several years, two totally implantable venous hemodialysis access devices have been developed: the LifeSite hemodialysis valve (Vasca Inc., Tewksbury, MA) (Figure 57–2), and the Dialock Access System (Biolink Inc., Norwell, MA). In the United States, only the LifeSite device became available. The LifeSite system consisted of two independently implanted subcutaneous valves, each connected to a single-lumen catheter placed into the right atrium. These were accessed using 14-gauge needles through a “buttonhole” tract. Disinfection with isopropyl alcohol before and after each dialysis needle access was essential to reduce serious device infections. The LifeSite system provided improved device survival and lower rates of infection than conventional tunneled dialysis catheters. Interventional nephrologists have been instrumental in the LifeSite clinical trials and the application of the LifeSite device in practice. However, considerably greater time, skill, risk, and expense were associated with the implantation of these devices, factors that had to be weighed when considering the use of these devices versus the use of a conventional venous catheter. There is also a significant “learning curve” for both the implanting physician and the dialysis nursing staff, requiring a number of patients to be maintained in a program with the LifeSite device in order to achieve consistent successful results.
Because the product did not gain wide acceptance in most nephrology communities, the manufacturing company, Vasca Inc., eventually decided to withdraw LifeSite from the market in 2005.