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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
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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 A negative correlation was found between intimal thickness and WSS Low WSS is strongly correlated to atherogenesis The low WSS values distribution is in accordance with the frequent localization of atherosclerosis lesion From Chatzisisis JACC 2006
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 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 2007 Valencia T Lefebvre Y Louvard
Flow dynamics in LM Bifurcation. Objective : • Effect of the bifurcationangle on flow dynamic in case of provisional stenting of LM bifurcation • Trajectography , Langragian approach
Flow dynamics in LM Bifurcation. Experimental setup : Oscilloscope Centrifugal Pump by-pass Bifurcation Pulsatil pump Unsteady Flowmeter CCD Camera Laser sheet
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)
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 open Provisional 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 • 90° Bifurcation : • 60° Bifurcation : Recirculation Shadow area 3D phenomenon
Flow dynamics in LM Bifurcation. Stent provisional stenting • 90° Bifurcation : • 60° Bifurcation : Recirculation Shadow area 3D phenomenon