A Retrospective Study of Palindrome Symmetrical-Tip Catheters for Chronic Hemodialysis Access in China

Journal: Renal Failure

Publication Date: 2015

Objective: To evaluate the effectiveness and safety of symmetric tip catheters for long-term hemodialysis.

Methods: A retrospective study involving 284 long-term hemodialysis catheter insertions in 271 Chinese patients treated with either symmetric tip (N=118) or step-tip (N=166) hemodialysis catheters. The study assessed the effectiveness and safety of symmetric tip catheters compared to step-tip catheters. Performance metrics included average catheter dwell time, incidence of low blood flow, and rates of infection and catheter-related bloodstream infections (CRBSI).

Results: The average dwell time of symmetric tip catheters was significantly longer than that of step-tip catheters. Symmetric tip catheters had lower rates of low blood flow, infections, and CRBSI, and a lower catheter removal rate.

Conclusion: Compared to step-tip catheters, symmetric tip hemodialysis catheters have a longer average dwell time, lower incidence of low blood flow, and lower infection rates.

Background:

•  The global population of elderly hemodialysis patients is increasing, along with the prevalence of diabetes and cardiovascular comorbidities. The number of patients requiring long-term hemodialysis who are unsuitable for arteriovenous fistulas is also rising, particularly in China.

•  For patients with problematic or impossible arteriovenous fistula creation (e.g., elderly patients with poor vascular conditions or those with poor cardiac function), long-term hemodialysis catheters remain a necessary vascular access.

•  Continuous improvements in catheter design have enhanced catheter durability and reduced infection rates. Studies have shown that symmetric tip catheters have several functional advantages over other designs: (1) lower thrombosis and recirculation rates compared to split-tip catheters; (2) lower dysfunction rates compared to step-tip catheters.

•  Clinical data describing the long-term performance of symmetric tip catheters for long-term hemodialysis have been relatively scarce.

Objective: To evaluate the long-term functionality and infection rates associated with symmetric tip hemodialysis catheters compared to step-tip catheters, assessing the effectiveness and safety of symmetric tip catheters for long-term hemodialysis.

Methods:

•  Study Design: Retrospective study

•  Study Period: May 2009 to December 2011

•  Study Location: Shanghai

•  Study Population: Patients with end-stage renal disease

•  Data Collection: Primarily catheter dwell time, incidence of low blood flow, infection rates, catheter-related bloodstream infections (CRBSI), and catheter removal

Results:

A total of 271 end-stage renal disease patients were included, with 284 long-term hemodialysis catheters inserted:

•  Catheter Types: 118 in Group A with symmetric tip catheters (including 14 step-tip catheters converted to symmetric tip); 166 in Group B with step-tip catheters

•  Common Insertion Route: Right internal jugular vein

•  Dwell Time: The average dwell time for the symmetric tip catheter group was significantly longer than that for the step-tip catheter group (329.4±38.1 vs. 273.1±25.4 catheter days)

•  Incidence of Low Blood Flow: The incidence of low blood flow was significantly lower for the symmetric tip catheters (1.13 vs. 6.86 per 1000 catheter days)

•  Removal Rate: The number of removals was lower for symmetric tip catheters compared to step-tip catheters (10 vs. 26)

•  Infection Rate: The infection rate was lower in the symmetric tip catheter group compared to the step-tip catheter group (0.28 vs. 0.78 per 1000 catheter days)

•  CRBSI Rate: The rate of catheter-related bloodstream infections (CRBSI) was lower in the symmetric tip catheter group compared to the step-tip catheter group (0.13 vs. 0.42 per 1000 catheter days)

•  Recirculation Rate: The recirculation rate was 0% in symmetric tip catheters, with no poor blood flow during reverse connection; in step-tip catheters, the recirculation rate was 0-5%, with 5 cases of poor blood flow during reverse connection.

Conclusions:

Compared to step-tip hemodialysis catheters, symmetric tip catheters have a longer average dwell time, lower incidence of low blood flow, and lower infection rates. These results support the feasibility of using symmetric tip catheters to establish long-term vascular access in patients unsuitable for arteriovenous fistulas and requiring long-term hemodialysis.

Implications:

•  This study provides valuable contributions to the existing literature on the use of symmetric tip catheters for long-term hemodialysis and offers the first report on their use in China.

•  The symmetric helical tip design allows for inflow through laser-cut side slots near the tip and outflow as a jet away from the catheter tip. This design is believed to prevent clot formation and reduce the formation of thrombi and fibrin sheaths.

•  Hemodialysis catheters remain a necessary option for patients who cannot undergo arteriovenous fistula placement. Therefore, given the importance of adequate vascular access for patients requiring hemodialysis, improvements in catheter design aim to enhance long-term functionality while reducing infection and complication rates.