Most balloon angioplasty procedures include the insertion of tiny cylindrical wire mesh structures, called cardiovascular stents, into the artery to prevent the elastic recoil that follows arterial dilatation. The scaffolding characteristics of the stent provide strength to the artery wall. However, vascular injury during stent deployment and∕or recognition of the stent as a foreign material triggers neointimal hyperplasia, causing re-closure, or restenosis, of the artery. A recent advancement to counteract restenosis is to employ drug-eluting stents to locally deliver immunosuppressant and antiproliferative drugs. In this project, Fick’s law of diffusion was used to model drug diffusion from the stent matrix into the adjacent arterial tissue. An analytical procedure was also developed to estimate the circumferential and the flexural stiffnesses of stents. Furthermore, a unique auxetic (negative Poisson’s ratio) stent structure was proposed that exhibits high circumferential strength in its expanded configuration and low flexural rigidity in its crimped configuration. Results generated with the analytical diffusion model, developed in this project, compare favorably with previously published clinical and experimental data. The circumferential and flexural stiffnesses estimated using the analytical procedure developed in this project compare favorably with the results from rigorous finite element analyses and previously published experimental data.

1.
Michaels
,
A. D.
, and
Chatterjee
,
K.
, 2002, “
Angioplasty Versus Bypass Surgery for Coronary Artery Disease
,”
Circulation
0009-7322,
106
, pp.
187
190
.
2.
King
,
S. B.
, 1996, “
Angioplasty From Bench to Bedside to Bench
,”
Circulation
0009-7322,
93
, pp.
1621
1629
.
3.
Windecker
,
S.
,
Roffi.
,
M.
, and
Meier
,
B.
, 2003, “
Sirolimus Eluting Stent: A New Era in Interventional Cardiology
,”
Curr. Pharm. Des.
,
9
, pp.
1077
1094
.
4.
Serruys
,
P. W.
, and
Kutryk
,
M. J. B.
, 1998,
Handbook of Coronary Stents
,
Mosby—A Times Mirror Company
,
St. Louis, MO
, p.
17
.
5.
Perin
,
E. C.
, 2005, “
Choosing a Drug-Eluting Stent: A Comparison Between CYPHER and TAXUS
,”
Rev. Cardiovasc. Med.
,
6
(Suppl. 1), pp.
S13
S21
.
6.
U. S. Food and Drug Administration
, 2003, “
FDA Approves Drug-Eluting Stent for Clogged Heart Arteries
,” FDA News Release, http://www.fda.gov/bbs/topics/NEWS/2003/NEW00896.htmlhttp://www.fda.gov/bbs/topics/NEWS/2003/NEW00896.html.
7.
U. S. Food and Drug Administration
, 2004, “
TAXUS™ Express2™ Paclitaxel-Eluting Coronary Stent System—P030025
,” FDA New Device Approval, http://www.fda.gov/cdrh/mda/docs/p030025.htmlhttp://www.fda.gov/cdrh/mda/docs/p030025.html.
8.
Zimmerman
,
J. J.
, and
Kahan
,
B. D.
, 1997, “
Pharmacokinetics of Sirolimus in Stable Renal Transplant Patients After Multiple Oral Dose Administration
,”
JPEN J. Parenter Enteral Nutr.
0148-6071,
37
, pp.
405
415
.
9.
Tanabe
,
K.
,
Regar
,
E.
,
Lee
,
C. H.
,
Hoye
,
A.
,
van der Giessen
,
W. J.
, and
Serruys
,
P. W.
, 2004, “
Local Drug Delivery Using Coated Stents: New Developments and Future Perspectives
,”
Curr. Pharm. Des.
,
10
, pp.
357
367
.
10.
Sousa
,
J. E.
,
Serruys
,
P. W.
, and
Costa
,
M. A.
, 2003, “
New Frontiers in Cardiology Drug-Eluting Stents: Part I
,”
Circulation
0009-7322,
107
, pp.
2274
2279
.
11.
Lau
,
K. W.
,
Mak
,
K. H.
,
Hung
,
J. S.
, and
Sigwart
,
U.
, 2004, “
Clinical Impact of Stent Construction and Design in Percutaneous Coronary Intervention
,”
Am. Heart J.
0002-8703,
147
, pp.
764
773
.
12.
Murphy
,
B. P.
,
Savage
,
P.
,
McHugh
,
P. E.
, and
Quinn
,
D. F.
, 2003, “
The Stress-Strain Behavior of Coronary Stent Struts is Size Dependent
,”
Ann. Biomed. Eng.
0090-6964,
31
(
6
), pp.
686
691
.
13.
Hwang
,
C. W.
,
Wu
,
D.
, and
Edelman
,
E. R.
, 2003, “
Impact of Transport and Drug Properties on the Local Pharmacology of Drug-Eluting Stents
,”
Int. J. Cardiovasc. Intervent.
,
5
, pp.
7
12
.
14.
Walline
,
K. S.
, 2004, “
Drug Delivery Coatings for Cardiovascular Stents: Silicone Elastomer and Thrombin Responsive Hydrogel Coatings
,” M. S. thesis, University of Washington, p.
9
.
15.
Myers
,
G. E.
, 1998,
Analytical Methods in Conduction Heat Transfer
,
AMCHT Publications
,
Madison, WI
.
16.
Carslaw
,
H. S.
, and
Jaeger
,
J. C.
, 1959,
Conduction of Heat in Solids
,
Clarendon Press
,
Oxford
.
17.
Sousa
,
J. E.
,
Costa
,
M. A.
,
Abizaid
,
A. S.
,
Feres
,
F.
,
Pinto
,
I. M. F.
,
Seixas
,
A. C.
,
Staico
,
R.
,
Mattos
,
L. A.
,
Sousa
,
A. G. M. R.
,
Falotico
,
R.
,
Jaeger
,
J.
,
Popma
,
J. J.
, and
Serruys
,
P. W.
, 2001, “
Lack of Neointimal Proliferation After Implantation of Sirolimus-Coated Stents in Human Coronary Arteries—A Quantitative Coronary Angiography and Three-Dimensional Intravascular Ultrasound Study
,”
Circulation
0009-7322,
103
, pp.
192
195
.
18.
Fajade
,
J.
,
Morice
,
M. C.
,
Bode
,
C.
,
Barragan
,
P.
,
Serruys
,
P. W.
,
Wijns
,
W.
,
Constantini
,
C. R.
,
Guermonprez
,
J. L.
,
Eltchaninoff
,
H.
,
Blanchard
,
D.
,
Bartorelli
,
A.
,
Laarman
,
G. J.
,
Perin
,
M. A.
,
Sousa
,
J. E.
,
Shuler
,
G.
,
Molnar
,
F.
,
Guagliumi
,
G.
,
Colombo
,
A.
,
Hayashi
,
E. B.
, and
Wulfert
,
E.
, 2005, “
Maintenance of Long-Term Clinical Benefit With Sirolimus-Eluting Coronary Stents—Three-Year Results of the RAVEL Trial
,”
Circulation
0009-7322,
111
, pp.
1040
1044
.
19.
Suzuki
,
T.
,
Kopia
,
G.
,
Hayashi
,
S.
,
Bailey
,
L. R.
,
Llanos
,
G.
,
Wilensky
,
R.
,
Klugherz
,
B. D.
,
Papandreou
,
G.
,
Narayan
,
P.
,
Leon
,
M. B.
,
Yeung
,
A. C.
,
Tio
,
F.
,
Tsao
,
P. S.
,
Falotico
,
R.
, and
Carter
,
A. J.
, 2001, “
Stent-Based Delivery of Sirolimus Reduces Neointimal Formation in a Porcine Coronary Model
,”
Circulation
0009-7322,
104
, pp.
1188
1193
.
20.
Klugherz
,
B. D.
,
Llanos
,
G.
,
Lieuallen
,
W.
,
Kopia
,
G. A.
,
Papandreou
,
G.
,
Narayan
,
P.
,
Sasseen
,
B.
,
Adelman
,
S. J.
,
Falotico
,
R.
, and
Wilensky
,
R. L.
, 2002, “
Twenty-Eight-Day Efficacy and Phamacokinetics of the Sirolimus-Eluting Stent
,”
Coron. Artery Dis.
0954-6928,
13
(
3
), pp.
183
188
.
21.
Virmani
,
R.
,
Kolodgie
,
F. D.
,
Farb
,
A.
, and
Lafont
,
A.
, 2003, “
Drug Eluting Stents: Are Human and Animal Studies Comparable?
Heart
1355-6037,
89
, pp.
133
138
.
22.
Jones
,
R. M.
, 1999,
Mechanics of Composite Materials
,
Taylor and Francis
,
PA
.
23.
Dolla
,
W. S.
, 2006, “
Drug Diffusion and Structural Design Criteria for Conventional and Auxetic Stents
,” Ph.D. dissertation, University of Missouri—Kansas City.
24.
Bauchau
,
O. A.
, 1983, “
Optimal Design of High Speed Rotating Graphite∕Epoxy Shafts
,”
J. Compos. Mater.
0021-9983,
17
(
2
), pp.
170
181
.
25.
Tsai
,
S. W.
, and
Pagano
,
N. J.
, 1968, “
Invariant Properties of Composite Materials
,” in Composite Materials Workshop, Technomic, CN, also in AFML-TR-67-349.
26.
Roguin
,
A.
, and
Bayer
,
R.
, 1998, “
BeStent—The Serpentine Balloon Expandable Stent: Review of Mechanical Properties and Clinical Experience
,”
Artif. Organs
0160-564X,
22
(
3
), pp.
243
249
.
27.
Lu
,
X.
,
Pandit
,
A.
, and
Kassab
,
G. S.
, 2004, “
Biaxial Incremental Homeostatic Elastic Moduli of Coronary Artery: Two-Layer Model
,”
Am. J. Physiol. Heart Circ. Physiol.
0363-6135,
287
, pp.
H1663
1669
.
28.
Lakes
,
R. S.
, 1987, “
Foam Structures With a Negative Poisson’s Ratio
,”
Science
0036-8075,
235
, pp.
1038
1040
.
This content is only available via PDF.
You do not currently have access to this content.