Randomized comparison of split tip versus step tip high-flow hemodialysis catheters

Background. Our purpose was to compare the function and complications of two high-flow polyurethane hemodialysis catheters. Methods, This prospective, randomized trial compared the Ash-Split (MedComp) and Opti-Flow (Bard Access Systems) catheters. All patients referred for tunneled hemodialysis catheter placement were offered entry in the study, provided they met inclusion criteria. Catheters were placed by interventional radiologists using ultrasound and fluoroscopic guidance. Procedure time and initial complications were recorded. Effective (QbEff) catheter flow rates and recirculation were studied at baseline, one month, three and six months using ultrasonic dilution (Transonic) at various pump speeds (Qb). Episodes of catheter malfunction and infection were recorded. Catheter removal or six months was the study endpoint. Results. A total of 132 patients were enrolled in the trial. The groups did not differ as to age, sex distribution, height or weight (P > 0.05). Initial complications included kinking resulting in catheter failure (Optiflow N = 3), and tunnel bleeding (Optiflow N = 1: Ash N = 3). Adjusted mean flow rates (QbEff) at Qb300 were 299 mL/min Ash and 305 mL/min Optiflow (P = 0.06), at Qb400 were 365 mL/min Ash and 382 mL/min Optiflow (P = 0.01), and at QbMax were 414 mL/min Ash and 433 mL/min Optiflow (P = 0.03). Recirculation was significantly higher with the Optiflow catheter at most measurement points. Total late complications were lower in the Ash group (P = 0.04), and catheter survival was significantly higher in the Ash group (P = 0.02). Conclusions. Both catheters can deliver flow rates well beyond those recommended by the Dialysis Outcomes Quality Initiative. While the Optiflow delivered higher flow rates at some measurement points, this was offset by higher recirculation. The Ash catheter showed a long-term survival advantage and fewer late complications.