Hemodialysis Catheter Design and Catheter Performance: A Randomized Controlled Trial

Journal: American Journal of Kidney Diseases

Publication Date: 2014

Objective: To evaluate the impact of different designs of symmetric tip and step-tip hemodialysis catheters on long-term catheter performance.

Methods: This study was a single-center, open-label, randomized controlled trial with a parallel-group design and a 1:1 allocation ratio, comparing the usage data of the two types of catheter tips.

Results: The number of urokinase infusions per 1000 catheter days was 17 for the symmetric tip and 35 for the step-tip. The percentage of catheters that never required thrombolysis was 58.3% for the symmetric tip and 45% for the step-tip. The average effective blood flow rates were 333 mL/min and 303 mL/min, respectively.

Conclusion: The symmetric tip hemodialysis catheter had a lower urokinase usage rate and higher blood flow rate compared to the step-tip catheter.

Background:

Tunneled cuffed catheters (TCCs) are frequently used in hemodialysis patients, primarily as a bridge for those with inadequate vascular anatomy, functional autogenous fistulas, or recovering renal function.

There are numerous TCCs available on the market, differing mainly in material type, lumen diameter, tip design, and side holes.

Specific design structures can improve hemodynamic characteristics and reduce thrombosis and infection rates, but definitive evidence is still needed.

Objective:

This randomized controlled trial aims to evaluate the impact of different tip designs of symmetric tip and step-tip long-term hemodialysis catheters on catheter performance.

Methods:

Study Location: AZ Sint-Jan Hospital, Bruges, Belgium

Methods: 302 patients were randomly assigned to two groups, receiving either symmetric tip catheters or step-tip catheters.

Exclusion Criteria:

1. Pregnancy or breastfeeding

2. Expected lifespan of less than one month due to major comorbid conditions

3. Inability to provide informed consent

4. Right internal jugular vein obstruction or inability to puncture

The study compared catheter patency and complication rates between the two groups.

Results:

A total of 302 patients were included, with 151 in the symmetric tip group and 151 in the step-tip group:

The mean primary assisted patency time was 135.9 days for the symmetric tip group and 136.5 days for the step-tip group.

The incidence of catheter-related bloodstream infections (CRBSI) was 0.24 and 0.10 per 1000 catheter days for the symmetric tip and step-tip groups, respectively.

The rate of thrombosis not resolved by thrombolysis was 0.53 and 0.43 per 1000 catheter days for the symmetric tip and step-tip groups, respectively.

The average effective blood flow rates were 333 mL/min and 303 mL/min for the symmetric tip and step-tip groups, respectively.

The number of catheters that never required thrombolysis was 88 in the symmetric tip group and 68 in the step-tip group.

The number of urokinase infusions per 1000 catheter days was 17 for the symmetric tip group and 35 for the step-tip group.

Conclusions:

The incidence of catheter-related bloodstream infections (CRBSI) and thrombosis was similarly low in both the symmetric tip and step-tip hemodialysis catheters. However, the symmetric tip catheter demonstrated a better blood flow rate, higher by 30 mL/min or 9%, compared to the step-tip catheter. Therefore, the symmetric tip is proven to be a valuable design for optimizing hemodialysis efficiency, with a lower rate of thrombolytic agent usage.

Implications:

This study is a single-center controlled trial, which has certain limitations. Future clinical studies with larger sample sizes are needed to confirm these findings.

The symmetric tip design offers more advantages in terms of higher flow rates, unaffected dialysis with reversed connections, and reduced urokinase usage.

While catheter design can influence catheter function to some extent, routine maintenance is equally important.