simulation of drug release (what for)?...cutrì et al. drug delivery patterns for different stenting...
TRANSCRIPT
Welcome to the 8th
European Bifurcation Club
12-13 October 2012 - Barcelona
Simulation of drug release
(what for)?
Gabriele Dubini
Professor of Biomechanics
at Politecnico di Milano
Aim of the study
Assessment of the effectiveness of different DES
stenting techniques in supplying drug to the arterial wall.
Computational analysis combining virtual stent implantation (a),
fluid dynamics (c) and drug release (b).
Computational model are able to provide fundamental indices which are
hardly detectable by means of in vitro or in vivo experiments.
Aim of the study
Mechanics: analysis of balloon/stent expansion
Fluid dynamics Mass transfer
blood flow
intramural plasma
filtration
drug release to the artery
drug release from the polymer
(Heparin)
• Realistic geometries of the deformed configurations
• Realistic drug distribution
within the arterial wall
• Effect of the stent struts
overlapping and/or
incomplete stent apposition
• Hemodynamic field
Zunino et al., CMAME (2009)
Stenting procedures
Tryton-based Culotte
Stenting procedures
Provisional
Side Branch Culotte
Tryton-based
Culotte
Fluid dynamics model
70/30 flow division MB/SB
x plasma
filtration
plasma
filtration
Deeper drug penetration
into the arterial wall in the
case where the plasma
filtration is accounted for
Drug release: multiscale strategy
Multiscale strategy:
0D model for the release rate in the stent coating;
3D model for the drug release within the arterial wall;
1D model to handle complex geometry of the DESs.
0D
1D
3D
Cutrì et al. Drug delivery patterns for different
stenting techniques in coronary bifurcations: a
comparative computational study.
Biomechanics Model Mechanobiol. 2012.
Quantities of interest
dw(x) = T-1 c
w(t,x)dt
0
T
ò
dw,m
(V ) = V -1 dw(x)dV
V
ò
Dose
Mean value of the dose
4 control volumes:
• red: whole arterial domain (V-TOT)
• blue box: proximal region of the main branch (V-MBP)
• green box: distal region of the main branch (V-MBP)
• yellow box: side branch (V-MBP)
Results R
ele
as
e o
n
Re
lea
se o
ff
PSB Culotte Tryton-based Culotte
Results
Results
Drug loss due to overlapping
Results
Results
Drug supply
to the SB
Results
BMS Tryton disturbs drug elution
Conclusions
Implementation of a drug-eluting stent model
based on realistic structural simulations.
Importance of a DES deployment in the side
branch to adequately supply drug.
Reduction of drug uptake due to stent
overlapping and incomplete stent apposition.
Acknowledgments
University of Pittsburgh
Prof. Paolo Zunino
Politecnico di Milano
Dr. Elena Cutrì
Prof. Francesco Migliavacca
Ing. Stefano Morlacchi
Ing. Claudio Chiastra