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Comparison of recirculation percentage of the palindrome catheter and standard hemodialysis catheters in a swine model.

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.