Purpose: The purpose of this study was to evaluate in vivo recirculation of a new bi-directional dialysis catheter with a symmetric tip design and compare it to currently marketed staggered and split tip catheters.
Materials and methods: Twelve catheters were placed in three 70-kg male swine. The catheters were connected to a roller type peristaltic pump. Blood flow and recirculation rates were measured with ultrasound (US) dilution. Recirculation was measured in blood flow rates of 300 mL/min, 400 mL/min, and 500 mL/min. The dialysis lines were then reversed and recirculation was measured in flow rate of 400 mL/min. Measurements were conducted with the catheter tip in the right atrium (RA) and repeated with the catheter tip in the superior vena cava (SVC).
Results: Recirculation rates measured with the Palindrome catheter tip (Tyco Healthcare Group LP, Mansfield, MA) in the SVC and in the RA were 0%. When the dialysis lines were reversed, the Palindrome catheter average recirculation was 0% with the tip in the SVC and 1% (0%-3%) with the tip in the RA. The average recirculation rates measured with the split tip catheter were 1% (0%-10%) in the SVC and 0% when the catheter tip was in the RA. When the dialysis lines were reversed split tip catheter recirculation was 11% (9%-16%) with the tip in the SVC and 13% (7%-18%) with the tip in the RA. With the staggered tip catheter, 1% (0%-5%) recirculation was measured. When the dialysis lines were reversed, the average recirculation in the staggered tip catheter measured 23% (18%-30%). Recirculation rate with reversal of dialysis lines was significantly lower with the Palindrome catheter when compared to the split tip and staggered tip designs (P < .05).
Conclusions: Preliminary results in vivo indicate that the Palindrome catheter demonstrates minimal recirculation with reversal of the dialysis lines compared to currently marketed split tip and staggered tip catheters.