Welcome to the 8th
European Bifurcation Club
12-13 October 2012 - Barcelona
Numerical models
of single- and double-
stenting procedures
Stefano Morlacchi
Politecnico di Milano
Stenting procedures in bifurcations
Stenting procedures in bifurcations
Lower clinical
outcomes
Technical
complexities
CBL are still an
open challenge
Improvement of the current state-of-the-art
Numerical methods
Numerical
methods
Advantages:
- Assessment of biomechanical quantities: arterial stress,
wall shear stress, deformations.
- Comparative evaluation of different techniques.
- Optimization of the current devices and design of new
concepts.
Numerical methods
Clinical
studies
In vitro
experiments
Numerical
methods
Advantages:
- Assessment of biomechanical quantities: arterial stress,
wall shear stress, deformations.
- Comparative evaluation of different techniques.
- Optimization of the current devices and design of new
concepts.
Numerical methods
Clinical
studies
In vitro
experiments
Numerical
methods
Advantages:
- Assessment of biomechanical quantities: arterial stress,
wall shear stress, deformations.
- Comparative evaluation of different techniques.
- Optimization of the current devices and design of new
concepts.
Aim of this work
Virtual simulation of
stenting procedures in
coronary bifurcations.
Aim of this work
Virtual simulation of
stenting procedures in
coronary bifurcations.
Fluid dynamics
model of the
hemodynamic field.
Structural simulations
Morlacchi et al. “Sequential structural and fluid dynamic numerical
simulations of a stented bifurcated coronary artery”
Journal of Biomechanical Engineering 133(12):121010.
Structural simulations
Fluid dynamic simulations
Chiastra C et al. “Computational fluid dynamics of stented coronary bifurcations
studied with a hybrid discretization method”
European Journal of Mechanics - B/Fluids. 2012; 35:76–84.
INLET
OUTLET SB
30%
OUTLET MB
70 %
Flow rate
85 ml/min
Fluid dynamic simulations
Chiastra C et al. “Computational fluid dynamics
of stented coronary bifurcations studied with a
hybrid discretization method”
European Journal of Mechanics - B/Fluids. 2012;
35:76–84.
INLET
OUTLET SB
30%
OUTLET MB
70 %
Volume flow rate
85 ml/min
Stenting procedures in bifurcations
Provisional SB stenting
0 0.115 0.23
Velocity magnitude [m/s]
Stenting procedures in bifurcations
Culotte technique Provisional SB stenting
0 0.115 0.23
Velocity magnitude [m/s]
0 0.115 0.23
Velocity magnitude [m/s]
Stenting procedures in bifurcations
Simultaneous Kissing Stents
0 0.115 0.23
Velocity magnitude [m/s]
Stenting procedures in bifurcations
Crush technique Simultaneous Kissing Stents
0 0.115 0.23
Velocity magnitude [m/s]
0 0.115 0.23
Velocity magnitude [m/s]
Stenting procedures in bifurcations
T-stenting
0 0.115 0.23
Velocity magnitude [m/s]
Stenting procedures in bifurcations
T-stenting with
protrusion
T-stenting
0 0.115 0.23
Velocity magnitude [m/s]
0 0.115 0.23
Velocity magnitude [m/s]
Stresses in the devices Bulk-flow quantities
Near wall quantities
PSB CULOTTE Low WSS Area
STRUT
MALAPPOSITIONS
0.95
0.83
Arterial stresses and stent
configurations
Biomechanical quantities
Stresses in the devices Bulk-flow quantities
Near wall quantities
PSB CULOTTE Low WSS Area
STRUT
MALAPPOSITIONS
0.95
0.83
Arterial stresses and stent
configurations
Biomechanical quantities
Stresses in the devices Bulk-flow quantities
Near wall quantities
PSB CULOTTE Low WSS Area
STRUT
MALAPPOSITIONS
0.95
0.83
Arterial stresses and stent
configurations
Biomechanical quantities
Stresses in the devices Bulk-flow quantities
Near wall quantities
PSB CULOTTE Low WSS Area
STRUT
MALAPPOSITIONS
0.95
0.83
Arterial stresses and stent
configurations
Biomechanical quantities
Some examples
Strut malappositions in the SKS tecnhique.
Single- and double- stenting techniques.
Influence of procedural errors: stent protrusion in
the MB within the T-stenting technique.
Some examples
Strut malappositions in the SKS tecnhique.
Single- and double- stenting techniques.
Influence of procedural errors: stent protrusion in
the MB within the T-stenting technique.
Single- and double- procedures
PSB CULOTTE CRUSH
Single- and double- procedures
PSB CULOTTE CRUSH
Single- and double- procedures
PSB CULOTTE CRUSH
Single- and double- procedures
PSB CULOTTE CRUSH
0 0.23
Velocity [m/s]
Low velocities Low velocities
Single- and double- procedures
0 0.5
WSS [Pa]
PSB CULOTTE CRUSH
0 0.23
Velocity [m/s]
Low WSS Area Low WSS Area
Low velocities Low velocities
Some examples
Strut malappositions in the SKS tecnhique.
Single- and double- stenting techniques.
Influence of procedural errors: stent protrusion in
the MB within the T-stenting technique.
Effects of stent protrusion
T-stenting
with protrusion
T-stenting
Effects of stent protrusion
T-stenting
with protrusion
T-stenting
-0.05 0 0.05
Viscous shear stress [Pa]
Some examples
Strut malappositions in the SKS tecnhique.
Influence of procedural errors: stent protrusion in
the MB within the T-stenting technique.
Single- and double- stenting techniques.
Effects of strut malappositions C
UL
OT
TE
S
KS
0 0.125 0.25
Velocity magnitude [m/s]
0 0.125 0.25
Velocity magnitude [m/s]
LOW FLOW REGION
LOW FLOW REGION
Effects of strut malappositions C
UL
OT
TE
S
KS
0 0.125 0.25
Velocity magnitude [m/s]
0 0.125 0.25
Velocity magnitude [m/s]
NO STRUTS
NO STRUTS
Effects of strut malappositions
0 120 240
Max principal stress [kPa]
CU
LO
TT
E
SK
S
0 0.125 0.25
Velocity magnitude [m/s]
0 0.125 0.25
Velocity magnitude [m/s]
HIGH STRESS – ?NO DRUG?
Conclusions
Implementation of a sequential virtual model of
different stenting procedures for coronary
bifurcation lesions.
Application of the sequential model to assess both
structural and hemodynamic variables.
Comparisons among different single- or double-
stenting techniques.
Conclusions
Implementation of a sequential virtual model of
different stenting procedures for coronary
bifurcation lesions.
Application of the sequential model to assess both
structural and hemodynamic variables.
Comparisons among different single- or double-
stenting techniques.
Conclusions
Implementation of a sequential virtual model of
different stenting procedures for coronary
bifurcation lesions.
Application of the sequential model to assess both
structural and hemodynamic variables.
Comparisons among different single- or double-
stenting techniques.
Further developments
Image-based simulations of clinical cases.
In collaboration with Universitat Pomepeu Fabra, Barcelona.
CTA + CCA
3D model
Further developments
Validation of fluid dynamic fields with in-vitro tests.
In collaboration with Dr. Francesco Burzotta, Roma
and Prof. Vlachos, Virginia Tech, Blacksburg, USA.
PIV Imaging Bench test Flow measurement
Further developments
Drug elution numerical models.
In collaboration with prof. Paolo Zunino, University of Pittsburgh,
and Elena Cutrì, Mox, Politecnico di Milano.
EBC presentation by Prof. Gabriele Dubini.
Acknowledgements
Politecnico di Milano
Prof. Francesco Migliavacca
Prof. Gabriele Dubini
Dr. Elena Cutrì
Ing. Claudio Chiastra
Ing. Sebastian Colleoni
University of Pittsburgh
Prof. Paolo Zunino
THANK YOU FOR THE ATTENTION
Validation of structural results
COMPARISON WITH IN VITRO EXPANSION BY ORMISTON ET AL.
Validation of structural results
COMPARISON WITH IN VITRO EXPANSION BY SCHULTZ ET AL. 2009
In vitro
expansion Virtual
simulation