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

Abstract

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.

Comparison of Symmetric Hemodialysis Catheters Using Computational Fluid Dynamics

“…In 1996, the Ash Split Cath was developed, in which the arterial and venous lumens remained separate for a substantial portion of their tips but within a single device. The Tesio and Ash Split Cath designs (Medcomp, Harleysville, Pennsylvania) were less susceptible to positioning problems, and recirculation was reduced given the physical separation between the arterial and venous lumens (5,20,21). In 2005, the Palindrome symmetrical-tip catheter was introduced, which enabled aspiration and return of dialyzed blood through lumens that terminated at the same position within the device.…”

“…Differences in catheter tip design can produce significant differences in flow characteristics during the high-flow conditions required during dialysis, and in turn can have important implications for catheter thrombogenicity, recirculation, and other critical parameters of catheter performance (5). Symmetric-tip catheters have become alternatives to conventional step-tip and split-tip catheters, in part because of the ability to reverse lines during dialysis without an increase in recirculation (6).…”

Catheter Patency and Function after Catheter Sheath Disruption

“…Catheter dysfunction has been defined by Kidney Disease Outcomes Quality Initiative (K/DOQI) guidelines as "failure to maintain an extracorporeal blood flow sufficient to perform hemodialysis without significantly lengthening the hemodialysis treatment" (4). The guidelines and many research studies set a minimum blood flow target of 300 ml/min (5)(6)(7)(8)(9)(10)(11). Using this target, between 55 and 87% of catheters will experience dysfunction at least once (6,12), and 5 to 13% will require catheter replacement to treat dysfunction that is refractory to other measures such as patient repositioning, saline flushes, lumen reversal, and thrombolytic dwells (9 -11,13,14).…”

Interventional Nephrology

“…The split-tip catheters, on the other hand, had a significantly longer half-life (78% versus 64% at 120 days), as well as fewer late complications (17).…”

“…Since then, catheter design has evolved (15), with constant modifications in an attempt to provide maximal blood flow while minimizing infections and intimal trauma that lead to thrombosis (10). These changes in catheter design include individual catheters placed side by side, dual-lumen catheters, catheters with varying tip designs (step-tip, split-tip, and symmetric tipped catheters), and the self-centering superior vena cava catheter (15)(16)(17).…”