Dr Benjamin Lazarus1,2,3, Prof Kevan Polkinghorne2,3, Ms Sarah Coggan1, A/Prof Nicholas Gray4,5, A/Prof Girish Talaulikar6,7, Prof Martin Gallagher1,8, Dr Sradha Kotwal1,9
1The George Institute for Global Health, Newtown, Australia, 2Monash University, Melbourne, Australia, 3Monash Health, Clayton, Australia, 4University of the Sunshine Coast, Sippy Downs, Australia, 5Sunshine Coast University Hospital, Birtinya, Australia, 6The Canberra Hospital, Garran, Australia, 7Australia National University, Acton, Australia, 8UNSW South Western Sydney Campus, Sydney, Australia, 9UNSW Prince of Wales Hospital, Sydney, Australia
Aim: To determine whether tunnelled haemodialysis catheter (TCVC) tip design influences the risk of catheter dysfunction requiring removal.
Background: It is unknown whether TCVC tip design influences the risk of catheter dysfunction. In small, randomized controlled trials symmetrical tip catheters have favourable rheology compared to step-tip catheters.
Methods: We conducted a post-hoc analysis using data from the REDUcing the burden of dialysis Catheter ComplicaTIOns study (2016-2020). TCVC were classified into three distinct designs: symmetrical, step or split tips. Non-tunnelled catheters were excluded as were TCVC with missing tip design (n=945), and those with missing reason for removal (n=267) leaving 6209 TCVC in 4652 participants. The primary outcome was time to catheter removal due to poor flow as assessed by the treating clinician. Death and other reasons for catheter removal were considered competing events. We compared the risk of catheter dysfunction across different catheter tip designs using raw proportions and a multivariable Fine and Gray model with robust cluster variance estimators for clustering by service.
Results: Overall, 354 of 3881 (9.1%), 258 of 1873 (13.8%), and 39 of 455 (8.6%) TCVC with symmetrical, step and split tip designs respectively, were removed for catheter dysfunction. Relative to catheters with a symmetrical tip, catheters with step tip had a 53% higher risk of catheter dysfunction, which persisted after multivariable adjustment (subdistribution hazard ratio = 1.53, 95% CI: 1.24 – 1.89). No difference was observed for split tip catheters (sHR = 0.66, 95% CI: 0.31 – 1.38).
Conclusion: Tunnelled HD CVCs with a step tip have a higher risk of dysfunction than those with a symmetrical tip. Prospective, large randomized controlled trials are warranted to confirm this observation.
Biography:
Ben is an early career nephrologist at Monash Health and a full time PhD candidate at Monash University and The George Institute of Global Health. His thesis examines the risks of using central venous catheters for haemodialysis in Australia, and the opportunities we all have to make these devices safer for patients.