Retrospective Analysis of Catheter Recirculation in Prevalent Dialysis Patients

Catheter recirculation (CR) occurs when blood returning from the venous limb of the catheter re-enters the arterial limb of the catheter without passage through the circulation. Adequacy of dialysis is influenced by the degree of access recirculation. In this study we evaluate factors influencing the degree of dialysis central venous catheter (CVC) recirculation in prevalent hemodialysis patients. This is a retrospective study of all patients undergoing hemodialysis via a catheter at the Wake Forest University Outpatient Dialysis Facilities from September 1, 2006 to May 15, 2007. CR was correlated to catheter type, catheter brand, site of placement, catheter length, time on dialysis, time on the current catheter, and was measured via ultrasound dilution technique. A total of 165 catheters were identified. Seventy-one catheters were in the right internal jugular position, 43 in the left internal jugular position, 13 in the right subclavian, one in the left subclavian, eight in the right femoral, two in the left femoral, and four in the trans-lumber position. CR was 6.3 +/- 7.5% in symmetric tip catheters (n = 14), 6.0 +/- 8.3% in split-tip catheters (n = 102), 8.4 +/- 11.7% in step-tip catheters (n = 10), and 23.0 +/- 8.2% in temporary catheters (n = 3), respectively. These results are borderline significant if temporary catheters are included (p = 0.052); however, the overall p-value is only 0.80 for tunneled dialysis catheters. There was no correlation between CR and time on dialysis (p = 0.66) or time on the current catheter (p = 0.48). The current study suggests that the CVC recirculation is independent of catheter brand, type, time on dialysis, or time on current catheter.