Tunneled central venous catheters (CVC) are mainly considered as a rescue vascular access option in dialysis but are still used on approximately one quarter of prevalent patients worldwide even though they are associated with poor performances and higher risks.
Study design: in this retrospective single-center study, we aimed to report on the clinical performances achieved with high-flow tunneled CVCs (DualCath or DCath) and compared them with arteriovenous accesses (AVAs, e.g., AV fistula, AV graft, and Thomas Shunt) in a hospital-based dialysis unit.
Methods: Sixty-eight stage 5 chronic kidney disease dialysis-dependent patients (CKD5D) receiving high volume hemodiafiltration were followed-up with for 30 months. The study consisted of two phases: baseline cross-sectional and longitudinal follow-ups of key performance indicators. Clinical performances consisting of effective blood flow and blood volume, recirculation, urea and ionic Kt/V, total Kt, ultrafiltration volume, and percent reduction in β2-M were measured monthly as part of quality control in our unit.
Results: At baseline, the effective blood flow using a DCath was close to 400 mL/min, similar to an AVA. Recirculation with a DCath (7%, 6-13%) was higher than with an AVA. The diffusive dialysis dose delivered with a DCath (spKt and eKt/V) and convective dialysis dose achieved with a DCath were slightly lower than those achieved with AVAs, but they were still much higher than is recommended by guidelines. The percent reduction in β2-M achieved with a DCath was also 4 to 10% lower than that achieved with an AVA. On longitudinal follow-up, the main clinical performance indicators of DCaths (total Kt and total ultrafiltration volume, L/session) were maintained as very stable over time and close to those achieved with AVAs.
Conclusions: As shown in this study, high-flow DualCath tunneled two-single-lumen silicone catheters may be used to deliver high volume hemodiafiltration in a reliable and consistent manner without compromising clinical performance. These results relied on the specific design of the two silicone cannulas and the strict adherence to best catheter practices.
Keywords: convective dialysis dose; dialysis clinical performances; diffusive dialysis dose; effective blood flow; recirculation; tunneled central venous catheter; vascular access.