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