Impact of side-hole geometry on the performance of hemodialysis catheter tips: A computational fluid dynamics assessment

David G. Owen*, Diana C. de Oliveira, Shuang Qian, Naomi C. Green, Duncan E.T. Shepherd, Daniel M. Espino

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)
215 Downloads (Pure)

Abstract

Hemodialysis catheters are used to support blood filtration, yet there are multiple fundamentally different approaches to catheter tip design with no clear optimal solution. Side-holes have been shown to increase flow rates and decrease recirculation but have been associated with clotting/increased infection rates. This study investigates the impact of changing the shape, size and number of side-holes on a simple symmetric tip catheter by evaluating the velocity, shear stress and shear rate of inflowing blood. A platelet model is used to examine the residence time and shear history of inflowing platelets. The results show that side-holes improve the theoretical performance of the catheters, reducing the maximum velocity and shear stress occurring at the tip compared to non-side-hole catheters. Increasing the side-hole area improved performance up to a point, past which not all inflow through the hole was captured, and instead a small fraction slowly 'washed-out' through the remainder of the tip resulting in greater residence times and increasing the likelihood of platelet adhesion. An oval shaped hole presents a lower chance of external fibrin formation compared to a circular hole, although this would also be influenced by the catheter material surface topology which is dependent on the manufacturing process. Overall, whilst side-holes may be associated with increased clotting and infection, this can be reduced when side-hole geometry is correctly implemented though; a sufficient area for body diameter (minimising residence time) and utilising angle-cut, oval shaped holes (reducing shear stress and chances of fibrin formation partially occluding holes).

Original languageEnglish
Article numbere0236946
JournalPLoS ONE
Volume15
Issue number8
DOIs
Publication statusPublished - 7 Aug 2020

Keywords

  • Blood Flow Velocity
  • Blood Platelets/cytology
  • Catheters/statistics & numerical data
  • Computational Biology
  • Computer Simulation
  • Equipment Design
  • Hemodynamics
  • Humans
  • Hydrodynamics
  • Models, Cardiovascular
  • Platelet Adhesiveness
  • Renal Dialysis/instrumentation

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