flow dynamics in left-main bifurcation
DESCRIPTION
D. COISNE M.D. Ph.D *, E. FOUCAULT PhD**, S HUBERSON PhD ** L. CHRISTAENS M.D. * ,J MERGY MD *, P. BRAUD PhD ** *Poitiers University Hospital. **CNRS-Poitiers University. Flow Dynamics in Left-Main Bifurcation. WSS and endothelium. WSS is determined from velocity gradient and viscosity - PowerPoint PPT PresentationTRANSCRIPT
D. COISNE M.D. Ph.D *, E. FOUCAULT PhD**, S HUBERSON PhD **
L. CHRISTAENS M.D. * ,J MERGY MD *, P. BRAUD PhD **
*Poitiers University Hospital. **CNRS-Poitiers University
Flow Dynamics in Left-Main Bifurcation
WSS and endothelium
From Chatzisisis JACC 2006
WSS is determined from velocity gradient and viscosityA negative correlation was found between intimal thickness and WSSLow WSS is strongly correlated to atherogenesisThe low WSS values distribution is in accordance with the frequent localization of atherosclerosis lesion
Atherosclerotic plaque distribution in LMCT Scan study
• LM bifurcation:
L Christiaens study :
• “Distribution of atherosclerotic plaques in the left main coronary artery bifurcation: influence of anatomic variations of the proximal left coronary artery segments. A multi-slice computed tomography study over 300 cases. ”
Atherosclerotic plaque distribution in LMCT Scan study
Atherosclerotic plaque distribution in LMCT Scan study
More than 70% of plaques are located close to low WSS zones
French TAXUS registry• Impact of bifurcation angle ??. T Shape vs Y Shape
EBC 2007Valencia
T LefebvreY Louvard
Flow dynamics in LM Bifurcation.
• Objective :
-Effect of the bifurcation angle on flow dynamic in case of provisional stenting of LM bifurcation
-Trajectography , Langragian approach
Flow dynamics in LM Bifurcation.
• Experimental setup :
Oscilloscope
Pulsatil pump
Centrifugal Pump
by-pass
BifurcationUnstead
y Flowmet
er
Laser sheet
CCD Camera
Flow dynamics in LM Bifurcation.
• Experimental setup :
Modelisation :
Synthetic flow : Arbitrary Wave Generator . + pulsatil pump
Bifurcation models in glass (90°,60°)
Ultra-fast PIV measurements (3 kHz – 1024x1024 – 50 periods )
Standard PIV (50 pts/period – 50 periods – 2Hz )
Scale 1, Reynolds analogy (Water+glycerin)
Silver Hollow glass (15micron diameter)
-1
-0.5
0
0.5
1
1.5
-0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6
Time (=>N=2Hz)
Vol
tage
(mV
)
Flow dynamics in LM Bifurcation.
• Experimental device :
For 60° and 90° bifurcation angles
Normal bifurcation Without stent
With stent before Kissing procedure
With stent lateral struts openProvisional stenting , proximal crossing
Flow dynamics in LM Bifurcation.
• Provisional stenting
Flow dynamics in LM Bifurcation.
• Natural bifurcation :• 60° Bifurcation : • 90° Bifurcation :
Low velocity gradient zones/ Low WSS
Flow dynamics in LM Bifurcation.Stent before kissing procedure
• 60° Bifurcation : • 90° Bifurcation :
RecirculationShadow area3D phenomenon
Flow dynamics in LM Bifurcation.
Stent provisional stenting • 60° Bifurcation : • 90° Bifurcation :
RecirculationShadow area3D phenomenon