Article Text

Original research
Maximizing the catheter-to-vessel size optimizes distal flow control resulting in improved revascularization in vitro for aspiration thrombectomy
  1. Raul G Nogueira1,
  2. David Ryan2,
  3. Liam Mullins3,
  4. John Thornton4,
  5. Seán Fitzgerald5
  1. 1Marcus Stroke & Neuroscience Center, Grady Memorial Hospital, Emory University, Atlanta, Georgia, USA
  2. 2Department of Mechanical Engineering, National University of Ireland Galway, Galway, Ireland
  3. 3Perfuze Ltd, Galway, Ireland
  4. 4Department of Radiology, Royal College of Surgeons Ireland, Beaumont Hospital, Dublin, Ireland
  5. 5Department of Physiology, National University of Ireland Galway, Galway, Ireland
  1. Correspondence to Dr Seán Fitzgerald, Department of Physiology, National University of Ireland Galway, Galway, Ireland; sean.fitzgerald{at}


Background Balloon guide catheters (BGCs) achieve proximal flow control during thrombectomy but antegrade intracranial flow often persists via the Circle of Willis. Closely sizing an aspiration catheter to the target vessel might achieve greater flow control and improve technical performance. Our objective was to measure the impact of aspiration catheter size on distal flow control and flow reversal with and without the use of BGCs. Clot retrieval testing was performed to establish the impact of these parameters on revascularization.

Methods An in vitro thrombectomy model replicated in vivo conditions. Flow was measured continuously using ultrasonic flow sensors placed 20 cm distal to the catheter tip in the middlel cerebral artery (MCA). Four aspiration catheters of increasing size were evaluated: ACE 60 and 64 (Penumbra), SOFIA Plus (MicroVention), and Millipede 088 (Perfuze). Two clot analog types (red blood cell-rich and fibrin/platelet-rich) were used for clot retrieval testing.

Results The larger area of the ‘superbore’ Millipede 088 catheter resulted in a larger reduction in antegrade flow than standard aspiration catheters, even when the latter were combined with a BGC. During aspiration, 6Fr catheters were unable to cause flow reversal in the distal MCA while the Millipede 088 achieved significant distal flow reversal (−146 mL/min) (P<0.0001*) (*denotes significance). The solo use of Millipede 088 resulted in better recanalization outcomes and significantly reduced distal emboli for internal carotid artery (P=0.015*) and MCA (P=0.014*) occlusions compared with all other devices and combinations.

Conclusions Maximizing the catheter-to-vessel size facilitates near flow-arrest on catheter insertion, potentially negating the need for a BGC. A 0.088 inch aspiration catheter enables significant flow reversal in the distal MCA during aspiration.

  • balloon
  • catheter
  • stroke
  • thrombectomy
  • device

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  • Twitter @LiamMullins20, @FitzSeanT

  • Contributors SF was involved in all aspects of the study including study design, performing experiments, data analysis, and drafting the manuscript. DR participated in performing in vitro experiments and data analysis. LM participated in study design, data analysis, and drafting the manuscript. JT was involved in study design, data analysis, and drafting the manuscript. RGN was involved in all aspects of the study including study design, data analysis, and drafting the manuscript.

  • Funding This study was supported by Enterprise Ireland, Innovation Partnership Project IP-2019–0865 and co-funded by the Horizon 2020 programme of the European Union.

  • Competing interests SF received research funding from Enterprise Ireland that is co-funded by Perfuze Ltd. LM declares the following competing interest: Perfuze (stock options). JT declares the following competing interests: Perfuze (Physician Advisory Board, stock options); consultancy fees: MicroVention and Johnson & Johnson. RGN declares the following competing interests: consulting fees for advisory roles with Anaconda, Biogen, Cerenovus, Genentech, Imperative Care, Medtronic, Phenox, Prolong Pharmaceuticals, and Stryker Neurovascular and stock options for advisory roles with Astrocyte, Brainomix, Cerebrotech, Ceretrieve, Corindus Vascular Robotics, Vesalio, Viz-AI, and Perfuze.

  • Patient consent for publication Not required.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available from the corresponding author upon reasonable request.

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