| Flow structures at the proximal side-to-end anastomosis. Influence of geometry and flow division. | |
| | |
MedLine Citation:
|
PMID: 7666660 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Flow structures were visualized in transparent polyurethane models of proximal side-to-end vascular anastomoses, using planar illumination of suspended tracer particles. Both the effects of geometry and flow division were determined under steady and pulsatile flow conditions, for anastomosis angles of 15, 30, and 45 degrees. The flow patterns were highly three-dimensional and were characterized by a series of vortices in the fully occluded distal artery and two helical vortices aligned with the axis of the graft. In steady flow, above a critical Reynolds number, the flow changed from a laminar regime to one displaying time-dependent behavior. In particular, significant fluctuating velocity components were observed in the distal artery and particles were shed periodically from the occluded artery into the graft. Pairs of asymmetric flow patterns were also observed in the graft, before the onset of the time-dependent flow regime. The critical Reynolds number ranged from 427 to 473 and appeared to be independent of anastomosis angle. The presence of a patent distal artery had a significant effect on the overall flow pattern and led to the formation of a large recirculation region at the toe of the anastomosis. The main structures observed in steady flow, such as vortices in the distal artery and helical flow in the graft, were also seen during the pulsatile cycle. However, the secondary flow components in the graft were more pronounced in pulsatile flow particularly during deceleration of the flow waveform. At higher mean Reynolds numbers, there was also a greater mixing between fluid in the occluded arterial section and that in the graft. |
| | |
Authors:
|
P E Hughes; T V How |
Publication Detail:
|
Type: In Vitro; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Journal of biomechanical engineering Volume: 117 ISSN: 0148-0731 ISO Abbreviation: J Biomech Eng Publication Date: 1995 May |
Date Detail:
|
Created Date: 1995-10-06 Completed Date: 1995-10-06 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 7909584 Medline TA: J Biomech Eng Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 224-36 Citation Subset: IM |
Affiliation:
|
Department of Clinical Engineering, University of Liverpool, United Kingdom. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Arteries
/
pathology,
physiopathology,
surgery Biomechanics Biomedical Engineering Blood Vessel Prosthesis* / adverse effects Hemodynamics / physiology* Hemorheology Humans Hyperplasia Models, Cardiovascular |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: The effect of pulsatile frequency on wall shear in a compliant cast of a human aortic bifurcation.
Next Document: Blood flow velocity profiles in pulmonary branch arteries in lambs.