1. 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

2. WSS and endothelium From Chatzisisis JACC 2006 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

3. Atherosclerotic plaque distribution in LM CT 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. ”

4. Atherosclerotic plaque distribution in LM CT Scan study More than 70% of plaques are located close to low WSS zones

5. French TAXUS registry Impact of bifurcation angle ??. T Shape vs Y Shape EBC 2007 Valencia T Lefebvre Y Louvard

6. 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

7. Flow dynamics in LM Bifurcation. Experimental setup : Oscillo scope Pulsatil pump Centrifugal Pump by-pass Bifurcation Unsteady Flowmeter Laser sheet CCD Camera

8. 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)

9. 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

10. Flow dynamics in LM Bifurcation. Provisional stenting

11. Flow dynamics in LM Bifurcation. Natural bifurcation : 60° Bifurcation : 90° Bifurcation : Low velocity gradient zones/ Low WSS

12. Flow dynamics in LM Bifurcation. Stent before kissing procedure 60° Bifurcation : 90° Bifurcation : Recirculation Shadow area 3D phenomenon

13. Flow dynamics in LM Bifurcation. Stent provisional stenting 60° Bifurcation : 90° Bifurcation : Recirculation Shadow area 3D phenomenon