Comparison of vortical structures induced by arteriovenous grafts using vector Doppler ultrasound

Efstratios Kokkalis; Andrew N Cookson; Peter A Stonebridge; George A Corner; J Graeme Houston; Peter R Hoskins

doi:10.1016/j.ultrasmedbio.2014.10.012

Comparison of vortical structures induced by arteriovenous grafts using vector Doppler ultrasound

Ultrasound Med Biol. 2015 Mar;41(3):760-74. doi: 10.1016/j.ultrasmedbio.2014.10.012.

Authors

Efstratios Kokkalis¹, Andrew N Cookson², Peter A Stonebridge³, George A Corner⁴, J Graeme Houston³, Peter R Hoskins⁵

Affiliations

¹ Institute for Medical Science and Technology, University of Dundee, Dundee, UK; Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK. Electronic address: E.Kokkalis@dundee.ac.uk.
² Department of Biomedical Engineering, King's College London, London, UK.
³ Cardiovascular and Diabetes Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, UK.
⁴ Medical Physics, Ninewells Hospital and Medical School, Dundee, UK.
⁵ Centre for Cardiovascular Science, University of Edinburgh, Edinburgh, UK.

PMID: 25683221
DOI: 10.1016/j.ultrasmedbio.2014.10.012

Abstract

Arteriovenous prosthetic grafts are used in hemodialysis. Stenosis in the venous anastomosis is the main cause of occlusion and the role of local hemodynamics in this is considered significant. A new spiral graft design has been proposed to stabilize the flow phenomena in the host vein. Cross-flow vortical structures in the outflow of this graft were compared with those from a control device. Both grafts were integrated in identical in-house ultrasound-compatible flow phantoms with realistic surgical configurations. Constant flow rates were applied. In-plane 2-D velocity and vorticity mapping was developed using a vector Doppler technique. One or two vortices were detected for the spiral graft and two to four for the control, along with reduced stagnation points for the former. The in-plane peak velocity and circulation were calculated and found to be greater for the spiral device, implying increased in-plane mixing, which is believed to inhibit thrombosis and neo-intimal hyperplasia.

Keywords: Arteriovenous prosthetic grafts; Circulation; Color Doppler; Flow mixing and stagnation; Flow phantom; Spiral flow; Vector Doppler ultrasound; Velocity; Vortical structures; Vorticity.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Arteriovenous Shunt, Surgical*
Blood Vessel Prosthesis*
Graft Occlusion, Vascular / diagnostic imaging*
Humans
Imaging, Three-Dimensional
Phantoms, Imaging
Renal Dialysis / instrumentation*
Ultrasonography, Doppler*
Ultrasonography, Doppler, Color