Skip to content

Maximising coverage of brain structures using controlled reflux, convection-enhanced delivery and the recessed step catheter

Research output: Contribution to journalArticle

  • Owen Lewis
  • Max Woolley
  • David E Johnson
  • Julia Fletcher
  • Johnathan Fenech
  • Mariusz W Pietrzyk
  • Neil U Barua
  • Alison S Bienemann
  • Will Singleton
  • Sam L Evans
  • Steven S Gill
Original languageEnglish
Pages (from-to)337-345
Number of pages9
JournalJournal of Neuroscience Methods
Early online date1 Sep 2018
DateAccepted/In press - 31 Aug 2018
DateE-pub ahead of print - 1 Sep 2018
DatePublished (current) - 1 Oct 2018



The design and use of convection-enhanced delivery catheters remains an active field as clinical trials have highlighted suboptimal distribution as a contributory factor to the failure of those studies. Recent studies indicate limitations and challenges in achieving target coverage using conventional point source delivery.


The recessed step catheter(RSC), developed by this group, does not function as a point source delivery device, but instead uses 'controlled reflux' of the infusate to a flow inhibiting recess feature. Here we investigate a range of clinically useful step lengths in agarose gel and investigate proof-of-principle in vivo(n = 5). Infusion morphology was characterised in terms of length, width and distribution volume over a range of flow rates.


For a fixed infusion volume, increases in catheter step length strongly correlated with increases in the length and volume of distribution (r>0.90, p < 0.001) whilst there were small reductions in the width of distribution (r<-0.62, p < 0.001). Step lengths below 6 mm produced spherical distributions while steps above 12 mm produced elongated distributions. Increasing peak flow rates resulted in significant reductions in distribution volume at each step length, and an increased risk of reflux beyond the step. Modifications to the infusion morphology using changes in step length were confirmed in vivo.


The combination of the recessed step and the ability to adjust the step length with this catheter design make it highly suitable for tailoring the distribution volume of the infusate to meet specific morphological target volumes in the brain.

    Research areas

  • Controlled reflux, CEDDIPG, Parkinson’s disease, Recessed-step-catheter, Convection-Enhanced Delivery



  • Full-text PDF (accepted author manuscript)

    Rights statement: This is the author accepted manuscript (AAM). The final published version (version of record) is available online via Elsevier at Please refer to any applicable terms of use of the publisher.

    Accepted author manuscript, 877 KB, PDF document

    Licence: CC BY-NC-ND


View research connections

Related faculties, schools or groups