Gérard FINET . MD PhD

1. European Bifurcation Club - September 2005 Lessons from IVUS in bifurcation lesions Department of Hemodynamics and Interventional Cardiology Cardiovascular Hospital - Hospices Civils de Lyon CNRS Creatis UMR 5515 and INSERM Unit 630 Claude Bernard University Lyon 1 Lyon - France Gérard FINET. MD PhD

2. Coronary bifurcation

3. Dmother D>4.5 mm D [4.5-4.0] D [4.0-3.5] D [3.5-3.0] D [3.0-2.5] D<2.5 mm Ratio 0.66 0.67 0.66 0.69 0.66 0.66 R = Ddaughter 1+Ddaughter 2 Fractals and self-similarity of the coronary tree (Submitted) 214 coronary bifurcations Bifurcation QCA (GEMSE) Ratio = 0.670 Dept. of Hemodynamics and Interventional Cardiology Cardiovascular Hospital Louis Pradel - Lyon - France

4. Dmother = 0.67 * (Ddaughter 1+Ddaughter 2 ) Relative deviation between the expected diameter of the mother vessel calculated with this formula and the measured diameter: -1.27% ± 9.85% On the design of the coronary arterial tree: a generalization of Murray’s law Yifang Zhou et al. Phys. Med. Biol. 44 (1999) 2929–2945. Dept. of Hemodynamics and Interventional Cardiology Cardiovascular Hospital Louis Pradel - Lyon - France

5. Do1 Di Qo1 Qi Qo2 0.67 Do2 For an incompressible fluid, The continuity formula is: Qo1+Qo2=Qi Q=SV If V=constant then Dept. of Hemodynamics and Interventional Cardiology Cardiovascular Hospital Louis Pradel - Lyon - France

6. Main vessel (3.33 ±0.94 mm) Side branch (2.23 ±0.68 mm) Dept. of Hemodynamics and Interventional Cardiology Cardiovascular Hospital Louis Pradel - Lyon - France

7. ∆D = 0.63 ±1.05 mm Ddaughter max= 2.70 ±0.77 mm Dmother = 3.33 ±0.94 mm Ddaughter min= 2.23 ±0.68 mm Dept. of Hemodynamics and Interventional Cardiology Cardiovascular Hospital Louis Pradel - Lyon - France

8. Dmother = 4.55 mm Ddaughter max = 3.32 mm Ddaughter min = 3.30 mm Bifurcation Coronary Lesions Treated With the “Crush” Technique An Intravascular Ultrasound Analysis R=0.687 Costa et al. JACC 2005;4:599.

9. Association of Arterial Expansion (Expansive Remodeling) of Bifurcation Lesions Determined by Intravascular Ultrasonography With Unstable Clinical Presentation Dept. of Hemodynamics and Interventional Cardiology Cardiovascular Hospital Louis Pradel - Lyon - France Schoenhagen et al. AJC 2001;88:785.

10. Example #1

11. Baseline After stent implantation Final result Example #2 Dept. of Hemodynamics and Interventional Cardiology Cardiovascular Hospital Louis Pradel - Lyon - France

12. ∆D=1.23 mm ∆D=0.34 mm Bifurcation Coronary Lesions Treated With the “Crush” Technique An Intravascular Ultrasound Analysis Costa et al. JACC 2005;4:599.

13. Mechanism of Lumen Enlargement Longitudinal representation(every 1 mm on 23-mm-long arterial segment), where the grey rectangle illustrates the stent location) of ∆L, ∆EEM, and ∆P+M volume changes of patients with DS vs SWP. ∆L volume (mm3) Vessel stretch: 67% ∆EEM volume (mm3) Plaque reduction: 33% ∆P+M volume (mm3) Finet et al. Heart 2003 ;89:84-90 Finet et al. AJC 2001 ;88:1179-1182.

14. Tissue compressibility Compressible tissue (=0.05) Incompressible tissue (=0.49) (Elasticity, E=100 KPa)

15. Mechanism of Lumen Enlargement Longitudinal representation (every 1 mm on 23-mm-long arterial segment, where the grey rectangle illustrates the stent location) of ∆P+M volume changes of patients with no plaque reduction (n=7 in each group). The preintervention lesion center is CL. Longitudinal stent centering:-0.4±2.3 mm ∆P+M volume (mm3) Longitudinal stent centering: 1.54±4.8 mm Finet et al. Heart 2003 ;89:84-90 Finet et al. AJC 2001 ;88:1179-1182.

16. Mechanism of Lumen Enlargement Postintervention (Direct stenting) Preintervention Finet et al. Heart 2003 ;89:84-90 Finet et al. AJC 2001 ;88:1179-1182.

18. My take-home messages Coronary bifurcation geometrical pattern is invariable whatever the observation scale and precisely described by a fractal ratio, this ratio can be very useful in our daily practice of angiography Coronary angiography isfundamentally insufficient for complete detection and description of all of the aspects of bifurcation lesions IVUS compensates the deficiencies of angiography, providing a useful complement IVUS exploration of the main vessel only appears sufficient because proximal analysis of the side branch is accurate Proximal stent malapposition is induced by the stepwise geometrical mother-daughter vessel discrepancy and requires systematic final kissing balloon