Theoretical Modeling of Cyclically Loaded, Biodegradable Cylinders

  • J. S. Soares
  • J. E. MooreJr.
  • K. R. Rajagopal
Part of the Modeling and Simulation in Science, Engineering and Technology book series (MSSET)


The adaptation of fully biodegradable stents, thought to be the next revolution in minimally invasive cardiovascular interventions, is supported by recent findings in cardiovascular medicine concerning human coronaries and the likelihood of their deployment has been made possible by advances in polymer engineering. The main potential advantages of biodegradable polymeric stents are: (1) the stent can degrade and transfer the load to the healing artery wall which allows favorable remodeling, and (2) the size of the drug reservoir is dramatically increased. The in-stent restenotic response usually happens within the first six months, thus a fully biodegradable stent can fulfill the mission of restoring flow while mitigating the probability of long-term complications. However, it is a key concern that the stent not degrade away too soon, or develop structural instabilities due to faster degradation in key portions of the stent. We present here a preliminary model of the mechanics of a loaded, biodegradable cylindrical structure. The eventual goal of this research is to provide a means of predicting the structural stability of biodegradable stents

As a first step towards a fully nonlinear model, biodegradable polymers are modeled as a class of linearized materials. An inhomogeneous field that reflects the degradation, which we henceforth refer to as degradation, and a partial differential equation governing the degradation are defined. They express the local degradation of the material and its relationship to the strain field. The impact of degradation on the material is accomplished by introducing a time-dependent Young’s modulus function that is influenced by the degradation field. In the absence of degradation, one recovers the classical linearized elastic model. The rate of increase of degradation was assumed to be dependent on time and linearized strain with the following characteristics: (1) a material degrades faster when it is exposed to higher strains, and (2) a material that is strained for a longer period of time degrades more rapidly than a material that has been strained by the same amount for a shorter period of time

The initial boundary value problem considered is that of an infinitely long, isotropic, nearly incompressible, homogeneous, and strain-degradable cylindrical annulus subjected to radial stresses at its boundaries. A semiinverse method assuming a specific form of the displacement field was employed and the problem reduced to two coupled nonlinear partial differential equations for a single spatial coordinate and time. These equations were solved simultaneously for the displacement and degradation fields using a time marching finite element formulation with a set of nonlinear iterations for each time step

The main features that were observed were: (1) strain-induced degradation showed acceptable phenomenological characteristics (i.e. progressive failure of the material and parametric coherence with the defined constants); (2) an inhomogeneous deformation leads to inhomogeneous degradation and therefore in an initially homogeneous body the properties vary with the current location of the particles; and (3) the linearized model, in virtue of degradation, exhibits creep, stress relaxation, and hysteresis, but this is markedly different from the similar phenomena exhibited by viscoelastic materials


Cyclically Load Biodegradable Polymer Radial Displacement Hoop Stress Polymer Degradation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. [AGa] Agrawal, C.M., and Clark, H.G., Deformation characteristics of a bioabsorbable intravascular stent. Invest. Radiol., 27 (1992), 1020–1024.Google Scholar
  2. [AGb]
    Agrawal, C.M., Haas, K.F., Leopold, D.A., and Clark, H.G., Evaluation of poly(L-lactic acid) as a material for intravascular polymeric stents. Biomaterials, 13 (1992), 176–182.Google Scholar
  3. [AHa]
    Ahn, Y.K., Jeong, M.H., Kim, J.W., et al., Preventive effects of the heparin-coated stent on restenosis in the porcine model. Catheter Cardiovasc. Interv., 48 (1999), 324–330.Google Scholar
  4. [ALa]
    Al Suwaidi, J., Berger, P.B., and Holmes, D.R., Jr., Coronary artery stents. JAMA, 284 (2000), 1828–1836.Google Scholar
  5. [ALb]
    Ali, S.A., Doherty, P.J., and Williams, D.F., Mechanisms of polymer degradation in implantable devices. 2. Poly(DL-lactic acid). J. Biomed. Mater. Res., 27 (1993), 1409–1418.Google Scholar
  6. [ALc]
    Ali, S.A., Zhong, S.P., Doherty, P.J., and Williams, D.F., Mechanisms of polymer degradation in implantable devices. 1. Poly (caprolactone). Biomaterials, 14 (1993), 648–656.Google Scholar
  7. [ARa]
    Ardissino, D., Cavallini, C., Bramucci, E., et al., Sirolimus-eluting vs. uncoated stents for prevention of restenosis in small coronary arteries: a randomized trial, JAMA, 292 (2004), 2727–2734.Google Scholar
  8. [ATa]
    Athanasiou, K.A., Agrawal, C.M., Barber, F.A., and Burkhart, S.S., Orthopaedic applications for PLA-PGA biodegradable polymers. Arthroscopy J. Arthroscopic Related Surg., 14 (1998), 726–737.Google Scholar
  9. [AXa]
    Axel, D.I., Kunert, W., Goggelmann, C., et al., Paclitaxel inhibits arterial smooth muscle cell proliferation and migration in vitro and in vivo using local drug delivery. Circulation, 96 (1997), 636–645.Google Scholar
  10. [BAa]
    Babapulle, M.N., and Eisenberg, M.J., Coated stents for the prevention of restenosis: Part II. Circulation, 106 (2002), 2859–2866.Google Scholar
  11. [BEa]
    Bedoya, J., Meyer, C.A., Timmins, L.H., Moreno, M.R., and Moore, J.E., Jr., Effects of stent design parameters on artery wall mechanics (submitted).Google Scholar
  12. [BEb]
    Bellenger, V., Ganem, M., Mortaigne, B., and Verdu, J., Lifetime prediction in the hydrolytic aging of polyesters. Polym. Degradation Stability, 49 (1995), 91–97.Google Scholar
  13. [BEc]
    Bertrand, O.F., Sipehia, R., Mongrain, R., et al., Biocompatibility aspects of new stent technology. J. Am. Coll. Cardiol., 32 (1998), 562–571.Google Scholar
  14. [BIa]
    Bier, J.D., Zalesky, P., Li, S.T., Sasken, H., and Williams, D.O., A new bioabsorbable intravascular stent: in vitro assessment of hemodynamic and morphometric characteristics. J. Interv. CardioL, 5 (1992), 187–194.Google Scholar
  15. [BLa]
    Blindt, R., Hoffmeister, K.M., Bienert, H., et al., Development of a new biodegradable intravascular polymer stent with simultaneous incorporation of bioactive substances. Int. J. Artif. Organs, 22 (1999), 843–853.Google Scholar
  16. [BOa]
    Bose, S.M., and Git, Y., Mathematical modelling and computer simulation of linear polymer degradation: Simple scissions. Macromol. Theor. Simul., 13 (2004), 453–473.Google Scholar
  17. [BRa]
    Browarzik, D., and Koch, A., Application of continuous kinetics to polymer degradation. J. Macromol. Sci. Pure Appl. Chem., 33A (1996), 1633–1641.Google Scholar
  18. [BUa]
    Burkersroda, F.v., Schedl, L., and Gopferich, A., Why degradable polymers undergo surface erosion or bulk erosion. Biomaterials, 23 (2002), 4221–4231.Google Scholar
  19. [COa]
    Colombo, A., and Karvouni, E., Biodegradable stents: “Fulfilling the mission and stepping away.” Circulation, 102 (2000), 371–373.Google Scholar
  20. [CUa]
    Currier, J.W., and Faxon, D.P., Restenosis after percutaneous transluminal coronary angioplasty: have we been aiming at the wrong target? J. Am. Coll. Cardiol., 25 (1995), 516–520.Google Scholar
  21. [DEa]
    De Scheerder, I.K., Wilczek, K.L., Verbeken, E.V., et al., Biocompatibility of biodegradable and nonbiodegradable polymer-coated stents implanted in porcine peripheral arteries. Cardiovasc. Intervent. Radiol., 18 (1995), 227–232.Google Scholar
  22. [DEb]
    De Scheerder, I.K., Wilczek, K.L., Verbeken, E.V., et al., Biocompatibility of polymer-coated oversized metallic stents implanted in normal porcine coronary arteries. Atherosclerosis, 114 (1995), 105–114.Google Scholar
  23. [DEc]
    DePalma, V.A., Baier, R.E., Ford, J.W., Glott, V.L., and Furuse, A., Investigation of three-surface properties of several metals and their relation to blood compatibility. J. Biomed. Mater. Res., 6 (1972), 37–75.Google Scholar
  24. [DIa]
    Di Mario, C., Griffiths, H., Goktekin, O., et al., Drug-eluting bioabsorbable magnesium stent. J. Interv. Cardiol., 17 (2004), 391–395.Google Scholar
  25. [DOa]
    Dotter, C.T., Transluminal angioplasty: A long view. Radiology, 135 (1980), 561–564.Google Scholar
  26. [DOb]
    Douglas, J.S., Jr., King, S.B., 3rd, and Roubin, G.S., Influence of the methodology of percutaneous transluminal coronary angioplasty on restenosis. Am. J. Cardiol., 60 (1987), 29B–33B.Google Scholar
  27. [DRa]
    Drumright, R.E., Gruber, P.R., and Henton, D.E., Polylactic acid technology. Adv. Mater., 12 (2000), 1841–1846.Google Scholar
  28. [DUa]
    Duda, S.H., Bosiers, M., Lammer, J., et al., Sirolimus-eluting versus bare nitinol stent for obstructive superficial femoral artery disease: The SIROCCO II trial. J. Vasc. Interv. Radiol., 16 (2005), 331–338.Google Scholar
  29. [DUb]
    Duda, S.H., Pusich, B., Richter, G., et al., Sirolimus-eluting stents for the treatment of obstructive superficial femoral artery disease: Six-month results. Circulation, 106 (2002), 1505–1509.Google Scholar
  30. [EDa]
    Edelman, E.R., and Rogers, C., Pathobiologic responses to stenting. Am. J. Cardiol., 81 (1998), 4E–6E.Google Scholar
  31. [FAa]
    Farb, A., Weber, D.K., Kolodgie, F.D., Burke, A.P., and Virmani, R., Morphological predictors of restenosis after coronary stenting in humans. Circulation, 105 (2002), 2974–2980.Google Scholar
  32. [FAb]
    Faxon, D.P., Vascular stents. Rev. Cardiovasc. Med., 2 (2001), 106–107.Google Scholar
  33. [FIa]
    Fischell, TA., Polymer coatings for stents. Can we judge a stent by its cover? Circulation, 94 (1996), 1494–1495.Google Scholar
  34. [FIb]
    Fischman, D.L., Leon, M.B., Baim, D.S., et al., A randomized comparison of coronary-stent placement and balloon angioplasty in the treatment of coronary-artery disease. N. Engl. J. Med., 331 (1994), 496–501.Google Scholar
  35. [GAa]
    Gallo, R., Padurean, A., Jayaraman, T., et al., Inhibition of intimai thickening after balloon angioplasty in porcine coronary arteries by targeting regulators of the cell cycle. Circulation, 99 (1999), 2164–2170.Google Scholar
  36. [GAb]
    Garlotta, D., A literature review of poly(lactic acid). J. Polym. Environ., 9 (2001), 63–84.Google Scholar
  37. [GLa]
    Glagov, S., Zarins, C.K., Masawa, N., Xu, CP., Bassiouny, H., and Giddens, D.P., Mechanical functional role of non-atherosclerotic intimai thickening. Front. Med. Biol. Eng., 5 (1993), 37–43.Google Scholar
  38. [GLb]
    Glagov, S., Intimai hyperplasia, vascular modeling, and the restenosis problem. Circulation, 89 (1994), 2888–2891.Google Scholar
  39. [GOa]
    Gopferich, A., and Langer, R., Modeling polymer erosion. Macromolecules, 26 (1993), 4105–4112.Google Scholar
  40. [GOb]
    Gopferich, A., Mechanisms of polymer degradation and elimination. In: Domb, A.J., Kost, J., and Wiseman, D.M., Eds. Handbook of Biodegradable Polymers. Harwood Academic, Australia (1997), 451–471.Google Scholar
  41. [GOc]
    Gopferich, A., Polymer degradation and erosion: Mechanisms and applications. Eur. J. Pharm. Biopharm., 4 (1996), 1–11.Google Scholar
  42. [GRa]
    Grabow, N., Martin, H., and Schmitz, K.P., The impact of material characteristics on the mechanical properties of a poly(L-lactide) coronary stent. Biomed. Tech. (Berl.), 47 (2002), 503–505.Google Scholar
  43. [GRb]
    Grabow, N., Schlun, M., Sternberg, K., Hakansson, N., Kramer, S., and Schmitz, K.P., Mechanical properties of laser cut poly(L-lactide) micro-specimens: Implications for stent design, manufacture, and sterilization. J. Biomech. Eng., 127 (2005), 25–31.Google Scholar
  44. [GRc]
    Grube, E., Gerckens, U., Muller, R., and Bullesfeld, L., Drug eluting stents: Initial experiences. Z. Kardiol., 91 (2002), 44–48.Google Scholar
  45. [GRd]
    Grube, E., Silber, S., Hauptmann, K.E., et al., TAXUS I: Sixand twelve-month results from a randomized, double-blind trial on a slow-release paclitaxel-eluting stent for de novo coronary lesions. Circulation, 107 (2003), 38–42.Google Scholar
  46. [GUa]
    Gutwald, R., Pistner, H., Reuther, J., and Muhling, J., Biodegradation and tissue-reaction in a long-term implantation study of poly (L-Lactide). J. Mater. Sci. Mater. Med., 5 (1994), 485–490.Google Scholar
  47. [HAa]
    Hawkins, W.L., Polymer degradation. In: Polymer degradation and stabilization. Springer-Verlag, Berlin (1984) 3–34.Google Scholar
  48. [HAb]
    Hayashi, T., Biodegradable polymers for biomedical uses. Prog. Polym. Sci., 19 (1994), 663–702.Google Scholar
  49. [HEa]
    Heublein, B., Rohde, R., Kaese, V., Niemeyer, M., Hartung W., and Haverich, A., Biocorrosion of magnesium alloys: A new principle in cardiovascular implant technology? Heart, 89 (2003), 651–656.Google Scholar
  50. [HIa]
    Hietala, E.M., Salminen, U.S., Stahls, A., et al., Biodegradation of the copolymeric polylactide stent. Long-term follow-up in a rabbit aorta model. J. Vasc. Res., 38 (2001), 361–369.Google Scholar
  51. [HOa]
    Holmes, D.R., Camrud, A.R., Jorgenson, M.A., Edwards, W.D., and Schwartz, R.S., Polymeric stenting in the porcine coronary artery model: Differential outcome of exogenous fibrin sleeves versus polyurethane-coated stents. J. Am. Coll. Cardiol., 24 (1994), 525–531.Google Scholar
  52. [HYa]
    Hyon, S.H., Jamshidi, K., and Ikada, Y., Effects of residual monomer on the degradation of DL-lactide polymer. Polym. Int., 46 (1998), 196–202.Google Scholar
  53. [ISa]
    Isotalo, T., Talja, M., Valimaa, T., Tormala, P., and Tammela, T.L., A bioabsorbable self-expandable, self-reinforced poly-L-lactic acid urethral stent for recurrent urethral strictures: Long-term results. J. Endourol., 16 (2002), 759–762.Google Scholar
  54. [IVa]
    Ivanova, T., Grozev, N., Panaiotov, I., and Proust, J.E., Role of the molecular weight and the composition on the hydrolysis kinetics of monolayers of poly(alpha-hydroxy acid)s. Colloid Polym. Sci., 277 (1999), 709–718.Google Scholar
  55. [JEa]
    Jeremias, A., Sylvia, B., Bridges, J., et al., Stent thrombosis after successful sirolimus-eluting stent implantation. Circulation, 109 (2004), 1930–1932.Google Scholar
  56. [JOa]
    Joshi, A., and Himmelstein, K.J., Dynamics of controlled release from bioerodible matrices. J. Control. Release, 15 (1991), 95–104.Google Scholar
  57. [KAa]
    Kastrati, A., Dibra, A., Eberle, S., et al., Sirolimus-eluting stents vs. paclitaxel-eluting stents in patients with coronary artery disease: meta-analysis of randomized trials. JAMA, 294 (2005), 819–825.Google Scholar
  58. [KAb]
    Kastrati, A., Hall, D., and Schomig, A., Long-term outcome after coronary stenting. Curr. Control Trials Cardiovasc. Med., 1 (2000), 48–54.Google Scholar
  59. [KAc]
    Katti, D.S., Lakshmi, S., Langer, R., and Laurencin, C.T., Toxicity, biodegradation and elimination of polyanhydrides. Adv. Drug Deliv. Rev., 54 (2002), 933–961.Google Scholar
  60. [KHa]
    Khang, G., Rhee, J.M., Jeong, J.K., et al., Local drug delivery system using biodegradable polymers. Macromol. Res., 11 (2003), 207–223.Google Scholar
  61. [KIa]
    Kimura, T., Yokoi, H., Nakagawa, Y., et al., Three-year follow-up after implantation of metallic coronary-artery stents. N. Engl. J. Med., 334 (1996), 561–566.Google Scholar
  62. [LAa]
    Labinaz, M., Zidar, J.P., Stack, R.S., and Phillips, H.R., Biodegradable stents: The future of interventional cardiology? J. Interv. Cardiol., 8 (1995), 395–405.Google Scholar
  63. [LAb]
    Lambert, T.L., Dev, V., Rechavia, E., Forrester, J.S., Litvack F, and Eigler, N.L., Localized arterial wall drug delivery from a polymercoated removable metallic stent. Kinetics, distribution, and bioactivity of forskolin. Circulation, 90 (1994), 1003–1011.Google Scholar
  64. [LAc]
    Langer, R., Drug delivery and targeting. Nature, 392 (1998), 5–10.Google Scholar
  65. [LAd]
    Laufman, H., and Rubel, T., Synthetic absorbable sutures. Surg. Gynecol. Obstet., 145 (1977), 597–608.Google Scholar
  66. [LEa]
    Lemos, P.A., Serruys, P.W., van Domburg, R.T., et al., Unrestricted utilization of sirolimus-eluting stents compared with conventional bare stent implantation in the “real world”: The Rapamycin-eluting stent evaluated at Rotterdam Cardiology Hospital (RESEARCH) registry. Circulation, 109 (2004), 190–195.Google Scholar
  67. [LEb]
    Levenberg, S., and Langer, R., Advances in tissue engineering. In: Current Topics in Developmental Biology, Vol 61. Elsevier, San Diego (2004) 113.Google Scholar
  68. [LIa]
    Li, S.M., and McCarthy, S., Further investigations on the hydrolytic degradation of poly(DL-lactide). Biomaterials, 20 (1999), 35–44.Google Scholar
  69. [LIb]
    Li, S.M., and Vert, M., Morphological-Changes Resulting from the hydrolytic degradation of stereocopolymers derived from L-lactides and D1-lactides. Macromolecules, 27 (1994), 3107–3110.Google Scholar
  70. [LIc]
    Libby, P., Schwartz, D., Brogi, E., Tanaka, H., and Clinton, S.K., A cascade model for restenosis. A special case of atherosclerosis progression. Circulation, 86 (1992), 11147–11152.Google Scholar
  71. [LId]
    Lincoff, A.M., Fürst, J.G., Ellis, S.G., Tuch, R.J., and Topol, E.J., Sustained local delivery of dexamethasone by a novel intravascular eluting stent to prevent restenosis in the porcine coronary injury model. J. Am. Coll. Cardiol., 29 (1997), 808–816.Google Scholar
  72. [LIe]
    Lincoff, A.M., Topol, E.J., and Ellis, S.G., Local drug delivery for the prevention of restenosis. Fact, fancy, and future. Circulation, 90 (1994), 2070–2084.Google Scholar
  73. [LIf]
    Lipinski, M.J., Fearon, W.F., Froelicher, V.F., and Vetrovec, G.W., The current and future role of percutaneous coronary intervention in patients with coronary artery disease. J. Interv. Cardiol., 17 (2004), 283–294.Google Scholar
  74. [LUa]
    Lunt, J., Large-scale production, properties and commercial applications of polylactic acid polymers. Polym. Degradation Stability, 59 (1998), 145–152.Google Scholar
  75. [MAa]
    Marx, S.O., Jayaraman, T., Go, L.O., and Marks, A.R., RapamycinFkbp inhibits cell-cycle regulators of proliferation in vascular smoothmuscle cells. Circulation Res., 76 (1995), 412–417.Google Scholar
  76. [MIa]
    Middleton, J.C., and Tipton, A.J., Synthetic biodegradable polymers as orthopedic devices. Biomaterials, 21 (2000), 2335–2346.Google Scholar
  77. [MIb]
    Mintz, G.S., Hoffmann, R., Mehran, R., et al., In-stent restenosis: The Washington Hospital Center experience. Am. J. Cardiol., 81 (1998), 7E–13E.Google Scholar
  78. [MIc]
    Mintz, G.S., Popma, J.J., Pichard, A.D., et al., Arterial remodeling after coronary angioplasty: A serial intravascular ultrasound study. Circulation, 94 (1996), 35–43.Google Scholar
  79. [MOa]
    Moore, J., Jr., and Berry, J.L., Fluid and solid mechanical implications of vascular stenting. Ann. Biomed. Eng., 30 (2002), 498–508.Google Scholar
  80. [MOb]
    Morice, M.C., Serruys, P.W., Sousa, J.E., et al., A randomized comparison of a sirolimus-eluting stent with a standard stent for coronary revascularization. N. Engl. J. Med., 346 (2002), 1773–1780.Google Scholar
  81. [Moc]
    Moses, J.W., Leon, M.B., Popma, J.J., et al., Sirolimus-eluting stents versus standard stents in patients with stenosis in a native coronary artery. N. Engl. J. Med., 349 (2003), 1315–1323.Google Scholar
  82. [MUa]
    Muller, D.W., Ellis, S.G., and Topol, E.J., Experimental models of coronary artery restenosis. J. Am. Coll. Cardiol., 19 (1992), 418–432.Google Scholar
  83. [MUb]
    Murphy, J.G., Schwartz, R.S., Edwards, W.D., Camrud, A.R., Vlietstra RE, and Holmes, D.R., Jr. Percutaneous polymeric stents in porcine coronary arteries. Initial experience with polyethylene terephthalate stents. Circulation, 86 (1992), 1596–1604.Google Scholar
  84. [MUc]
    Murphy, J.G., Schwartz, R.S., Huber, K.C., and Holmes, D.R., Jr. Polymeric stents: Modern alchemy or the future? J. Invasive. Cardiol., 3 (1991), 144–148.Google Scholar
  85. [NGa]
    Nguyen, K.T., Su, S.H., Sheng, A., et al., In vitro hemocompatibility studies of drug-loaded poly-(L-lactic acid) fibers. Biomaterials, 24 (2003), 5191–5201.Google Scholar
  86. [NGb]
    Nguyen, T.Q., and Kausch, H.H., GPC data interpretation in mechanochemical polymer degradation. Int. J. Polym. Anal. Characterization, 4 (1998), 447–470.Google Scholar
  87. [NGc]
    Nguyen, T.Q., Kinetics of mechanochemical degradation by gel permeation chromatography. Polym. Degradation Stability, 46 (1994), 99–111.Google Scholar
  88. [NUa]
    Nuutinen, J.P., Clerc, C., and Tormala, P., Theoretical and experimental evaluation of the radial force of self-expanding braided bioabsorbable stents. J. Biomater. Sci. Polym. Ed., 14 (2003), 677–687.Google Scholar
  89. [ONa]
    Ong, A.T., Serruys, P.W., and Aoki, J., et al., The unrestricted use of paclitaxelversus sirolimus-eluting stents for coronary artery disease in an unselected population: One-year results of the Taxus-Stent Evaluated at Rotterdam Cardiology Hospital (T-SEARCH) registry. J. Am. Coll. Cardiol., 45 (2005), 1135–1141.Google Scholar
  90. [OTa]
    Ottenbrite, R.M., Albertsson, and A.C., Scott, G., Discussion on degradation terminology. In: Vert, M., Feijen, J., Albertsson, A.C., Scott, G., Chiellini, E., Eds. Biodegradable Polymers and Plastics. The Royal Society of Chemisty, Cambridge (1992) 73–92.Google Scholar
  91. [PAa]
    Palmaz, J.C., Balloon-expandable intravascular stent. AJR Am. J. Roentgenol., 150 (1988), 1263–1269.Google Scholar
  92. [PEa]
    Peng, T., Gibula, P., Yao K.-d., and Goosen, M.F.A., Role of polymers in improving the results of stenting in coronary arteries. Biomaterials, 17 (1996), 685–694.Google Scholar
  93. [PEb]
    Peuster, M., Wohlsein, P., Brugmann, M., et al., A novel approach to temporary stenting: Degradable cardiovascular stents produced from corrodible metal-results 6–18 months after implantation into New Zealand white rabbits. Heart, 86 (2001), 563–569.Google Scholar
  94. [PIa]
    Pietrzak, W.S., Sarver, D.R., and Verstynen, M.L., Bioabsorbable polymer science for the practicing surgeon. J. Craniofac. Surg., 8 (1997), 87–91.Google Scholar
  95. [PIb]
    Pietrzak, W.S., Verstynen, M.L., and Sarver, D.R., Bioabsorbable fixation devices: Status for the craniomaxillofacial surgeon. J. Craniofac. Surg., 8 (1997), 92–96.Google Scholar
  96. [PIc]
    Pistner, H., Bendix, D.R., Muhling, J., and Reuther, J.F., Poly (L-Lactide) — A long-term degradation study invivo. 3. Analytical characterization. Biomaterials, 14 (1993), 291–298.Google Scholar
  97. [PId]
    Pistner, H., Gutwald, R., Ordung, R., Reuther, J., and Muhling, J., Poly(L-lactide) — A long-term degradation study in-vivo.l. Biological results. Biomaterials, 14 (1993), 671–677.Google Scholar
  98. [RAa]
    Rajagopal, K.R., and Wineman, A.S., A note on viscoelastic materials that can age. Int. J. NonLinear Mech., 39 (2004), 1547–1554.MATHGoogle Scholar
  99. [ROa]
    Robaina, S., Jayachandran, B., He, Y., et al., Platelet adhesion to simulated stented surfaces. J. Endovasc. Tier., 10 (2003), 978–986.Google Scholar
  100. [ROb]
    Rogers, C., and Edelman, E.R., Endovascular stent design dictates experimental restenosis and thrombosis. Circulation, 91 (1995), 2995–3001.Google Scholar
  101. [ROc]
    Roubin, G.S., Douglas, J.S., Jr., King, S.B., 3rd, et al., Influence of balloon size on initial success, acute complications, and restenosis after percutaneous transluminal coronary angioplasty. A prospective randomized study. Circulation, 78 (1988), 557–565.Google Scholar
  102. [SAa]
    Saia, F., Marzocchi, A., and Serruys, P.W., Drug-eluting stents. The third revolution in percutaneous coronary intervention. Ital. Heart J., 6 (2005), 289–303.Google Scholar
  103. [SAb]
    Sarembock, I.J., LaVeau, P.J., Sigal, S.L., et al., Influence of inflation pressure and balloon size on the development of intimai hyperplasia after balloon angioplasty. A study in the atherosclerotic rabbit. Circulation, 80 (1989), 1029–1040.Google Scholar
  104. [SCa]
    Schakenraad, J.M., Hardonk, M.J., Feijen, J., Molenaar, I., and Nieuwenhuis, P., Enzymatic activity toward poly(L-lactic acid) implants. J. Biomed. Mater. Res., 24 (1990), 529–545.Google Scholar
  105. [SCb]
    Schatz, R.A., Baim, D.S., Leon, M., et al., Clinical-experience with the Palmaz-Schatz coronary stent-Initial results of a multicenter study. Circulation, 83 (1991), 148–161.Google Scholar
  106. [SCc]
    Schatz, R.A., Introduction to intravascular stents. Cardiol. Clin., 6 (1988), 357–372.Google Scholar
  107. [SCd]
    Schnabel, W., Polymer Degradation. Macmillan, New York (1981).Google Scholar
  108. [SCe]
    Schofer, J., Schluter, M., Gershlick, A.H., et al., Sirolimus-eluting stents for treatment of patients with long atherosclerotic lesions in small coronary arteries: Double-blind, randomised controlled trial (E-SIRIUS). Lancet, 362 (2003), 1093–1099.Google Scholar
  109. [SCf]
    Schwartz, R.S., Neointima and arterial injury: Dogs, rats, pigs, and more. Lab. Invest., 71 (1994), 789–791.Google Scholar
  110. [SCg]
    Schwartz, R.S., Pathophysiology of restenosis: Interaction of thrombosis, hyperplasia, and/or remodeling. Am. J. Cardiol., 81 (1998), 14E–17E.Google Scholar
  111. [SEa]
    Serruys, P.W., Dejaegere, P., Kiemeneij, F., et al., A comparison of balloon-expandable-stent implantation with balloon angioplasty in patients with coronary-artery disease. N. Engl. J. Med., 331 (1994), 489–495.Google Scholar
  112. [SEb]
    Serruys, P.W., Emanuelsson, H., van der Giessen, W., et al., Heparincoated Palmaz-Schatz stents in human coronary arteries. Early outcome of the Benestent-II Pilot Study. Circulation, 93 (1996), 412–422.Google Scholar
  113. [SIa]
    Siepmann, J., and Gopferich, A., Mathematical modeling of bioerodible, polymeric drug delivery systems. Adv. Drug Delivery Rev., 48 (2001), 229–247.Google Scholar
  114. [SIb]
    Sigwart, U., Puel, J., Mirkovitch, V., Joffre, F., and Kappenberger, L., Intravascular stents to prevent occlusion and restenosis after transluminal angioplasty. N. Engl. J. Med., 316 (1987), 701–706.Google Scholar
  115. [SIc]
    Silber, S., Hamburger, J., Grube, E., et al., Direct stenting with TAXUS stents seems to be as safe and effective as with predilatation. A post hoc analysis of TAXUS II. Herz, 29 (2004), 171–180.Google Scholar
  116. [SId]
    Siparsky, G.L., Voorhees, K.J., and Miao, F.D., Hydrolysis of polylactic acid (PLA) and polycaprolactone (PCL) in aqueous acetonitrile solutions: Autocatalysis. J. Environ. Polym. Degradation, 6 (1998), 31–41.Google Scholar
  117. [STa]
    Staab, M.E., Holmes, D.R., and Schwartz, R.S., Polymers. In: Sigwart U, Ed. Endoluminal Stenting. WB Saunders, London (1996), 34–44.Google Scholar
  118. [STb]
    Stone, G.W., Ellis, S.G., Cox, D.A., et al., One-year clinical results with the slow-release, polymer-based, paclitaxel-eluting TAXUS stent: The TAXUS-IV trial. Circulation, 109 (2004), 1942–1947.Google Scholar
  119. [SUa]
    Su, S.H., Chao, R.Y., Landau, C.L., et al., Expandable bioresorbable endovascular stent. I. Fabrication and properties. Ann. Biomed. Eng., 31 (2003), 667–677.Google Scholar
  120. [TAa]
    Tamada, J.A., and Langer, R., Erosion kinetics of hydrolytically degradable polymers. Proceedings of the National Academy of Sciences of the United States of America, 90 (1993), 552–556.Google Scholar
  121. [TAb]
    Tamai, H., Igaki, K., Kyo, E., et al., Initial and 6-month results of biodegradable poly-1-lactic acid coronary stents in humans. Circulation, 102 (2000), 399–404.Google Scholar
  122. [TAc]
    Tamai, H., Igaki, K., Tsuji, T., et al., A biodegradable poly-L-lactic acid coronary stent in the porcine coronary artery. J. Interven. Cardiol., 12 (1999), 443–449.Google Scholar
  123. [TAd]
    Tammela, T.L., and Talja, M., Biodegradable urethral stents. B.JU Int., 92 (2003), 843–850.Google Scholar
  124. [TAe]
    Tanabe, K., Serruys, P.W., Grube, E., et al., TAXUS III Trial: Instent restenosis treated with stent-based delivery of paclitaxel incorporated in a slow-release polymer formulation. Circulation, 107 (2003), 559–564.Google Scholar
  125. [THa]
    Therasse, E., Soulez, G., Cartier, P., et al., Infection with fatal outcome after endovascular metallic stent placement. Radiology, 192 (1994), 363–365.Google Scholar
  126. [THb]
    Thombre, A.G., Theoretical aspects of polymer biodegradation: Mathematical modeling of drug release and acid-catalyzed poly(othoester) biodegradation. In: Vert, M., Feijen, J., Albertsson, A.C., Scott, G., Chiellini, E., Eds. Biodegradable Polymers and Plastics. The Royal Society of Chemisty, Cambridge (1992) 214–225.Google Scholar
  127. [TSa]
    Tsuji, T., Tamai, H., Igaki, K., et al., Biodegradable polymeric stents. Curr. Interv. Cardiol. Rep., 3 (2001), 10–17.Google Scholar
  128. [TSb]
    Tsuji, T., Tamai, H., Igaki, K., et al., Biodegradable stents as a platform to drug loading. Int. J. Cardiovasc. Intervent., 5 (2003), 13–16.Google Scholar
  129. [UNa]
    Unverdorben, M., Spielberger, A., Schywalsky, M., et al., A polyhydroxybutyrate biodegradable stent: Preliminary experience in the rabbit. Cardiovasc. Intervent. Radiol., 25 (2002), 127–132.Google Scholar
  130. [UUa]
    Uurto, I., Mikkonen, J., Parkkinen, J., et al., Drug-eluting biodegradable poly-D/L-lactic acid vascular stents: An experimental pilot study. J. Endovasc. Ther., 12 (2005), 371–379.Google Scholar
  131. [VAa]
    Valimaa, T., Laaksovirta, S., Tammela, T.L., et al., Viscoelastic memory and self-expansion of self-reinforced bioabsorbable stents. Biomaterials, 23 (2002), 3575–3582.Google Scholar
  132. [VAb]
    van der Giessen, W.J., Lincoff, A.M., Schwartz, R.S., et al., Marked inflammatory sequelae to implantation of biodegradable and nonbiodegradable polymers in porcine coronary arteries. Circulation, 94 (1996), 1690–1697.Google Scholar
  133. [VAc]
    van der Giessen, W.J., Slager, C.J., Gussenhoven, E.J., et al., Mechanical features and in vivo imaging of a polymer stent. Int. J. Card. Imaging., 9 (1993), 219–226.Google Scholar
  134. [VAd]
    van der Giessen, W.J., Slager, C.J., van Beusekom, H.M., et al., Development of a polymer endovascular prosthesis and its implantation in porcine arteries. J. Interv. Cardiol., 5 (1992), 175–185.Google Scholar
  135. [VAe]
    van der Giessen, W.J., Vanbeusekom H.M.M., Vanhouten, C.D., Vanwoerkens, L.J., Verdouw, P.D., and Serruys, P.W., Coronary stenting with, polymer-coated and uncoated self-expanding endoprostheses in pigs. Coronary Artery Disease, 3 (1992), 631–640.Google Scholar
  136. [VEa]
    Vert, M., Li, S., Garreau, H., et al., Complexity of the hydrolytic degradation of aliphatic polyesters. Angew Makromol Chem., 247 (1997), 239–253.Google Scholar
  137. [VEb]
    Vert, M., Li, S.M., Spenlehauer, G., and Guerin, P., Bioresorbability and biocompatibility of aliphatic polyesters. J. Mater. Sci. Mater. Med., 3 (1992), 432–446.Google Scholar
  138. [VEc]
    Vert, M., Aliphatic polyesters: Great degradable polymers that cannot do everything. Biomacromolecules, 6 (2005), 538–546.MathSciNetGoogle Scholar
  139. [VIa]
    Virmani, R., Liistro, F., Stankovic, G., et al., Mechanism of late instent restenosis after implantation of a paclitaxel derivate-eluting polymer stent system in humans. Circulation, 106 (2002), 2649–2651.Google Scholar
  140. [WEa]
    Weir, N.A., Buchanan, F.J., Orr, J.F., and Dickson, G.R., Degradation of poly-L-lactide. Part 1: In vitro and in vivo physiological temperature degradation. Proc Inst Mech Eng [H], 218 (2004), 307–319.Google Scholar
  141. [WEb]
    Weir, N.A., Buchanan, F.J., Orr, J.F., Farrar, D.F., and Dickson, G.R., Degradation of poly-L-lactide: Part 2: Increased temperature accelerated degradation. Proceedings of the Institution of Mechanical Engineers Part H-J. Eng. Med., 218 (2004), 321–330.Google Scholar
  142. [WEc]
    Wentzel, J.J., Krams, R., Schuurbiers, J.C., et al., Relationship between neointimal thickness and shear stress after Wallstent implantation in human coronary arteries. Circulation, 103 (2001), 1740–1745.Google Scholar
  143. [WEd]
    Wentzel, J.J., Whelan, D.M., van der Giessen, W.J., et al., Coronary stent implantation changes 3-D vessel geometry and 3-D shear stress distribution. J. Biomech., 33 (2000), 1287–1295.Google Scholar
  144. [WHa]
    Whelan, D.M., van Beusekom, H.M., and van der Giessen, W.J., Mechanisms of drug loading and release kinetics. Semin. Interv. Cardiol., 3 (1998), 127–131.Google Scholar
  145. [WIa]
    Williams, D.F., Biodegradation of surgical polymers. J. Mater. Sci., 17 (1982), 1233–1246.Google Scholar
  146. [YAa]
    Yamawaki, T., Shimokawa, H., Kozai, T., et al., Intramural delivery of a specific tyrosine kinase inhibitor with biodegradable stent suppresses the restenotic changes of the coronary artery in pigs in vivo. J. Am. Coll. Cardiol., 32 (1998), 780–786.Google Scholar
  147. [YEa]
    Ye, Y.W., Landau, C., Willard, J.E., et al., Bioresorbable microporous stents deliver recombinant adenovirus gene transfer vectors to the arterial wall. Ann. Biomed. Eng., 26 (1998), 398–408.Google Scholar
  148. [YOa]
    Yoon, J.S., Jin, H.J., Chin, I.J., Kim, C., and Kim, M.N., Theoretical prediction of weight loss and molecular weight during random chain scission degradation of polymers. Polymer, 38 (1997), 3573–3579.Google Scholar
  149. [ZAa]
    Zahn, R., Hamm, C.W., Schneider, S., et al., Incidence and predictors of target vessel revascularization and clinical event rates of the sirolimus-eluting coronary stent (results from the prospective multicenter German Cypher Stent Registry). Am. J. Cardiol., 95 (2005), 1302–1308.Google Scholar
  150. [ZHa]
    Zhang, Y., Zale, S., Sawyer, L., and Bernstein, H., Effects of metal salts on poly(DL-lactide-co-glycolide) polymer hydrolysis. J. Biomed. Mater. Res., 34 (1997), 531–538.Google Scholar
  151. [ZIa]
    Zidar, J., Lincoff, A., and Stack, R., Biodegradable stents. In: Topol, E.J., Ed. Textbook of Interventional Cardiolology. 2nd ed. WB Saunders, Philadelphia (1994), 787–802.Google Scholar
  152. [ZIb]
    Zilberman, M., Nelson, K.D., and Eberhart, R.C., Mechanical properties and in vitro degradation of bioresorbable fibers and expandable fiber-based stents. J. Biomed. Mater. Res. B Appl. Biomater., 74 (2005), 792–799.Google Scholar
  153. [ZIc]
    Zilberman, M., Schwade, N.D., and Eberhart, R.C., Protein-loaded bioresorbable fibers and expandable stents: Mechanical properties and protein release. J. Biomed. Mater. Res. B Appl. Biomater., 69 (2004), 1–10.Google Scholar

Copyright information

© Birkhäuser Boston 2007

Authors and Affiliations

  • J. S. Soares
    • 1
  • J. E. MooreJr.
    • 2
  • K. R. Rajagopal
    • 1
    • 2
  1. 1.Department of Mechanical EngineeringTexas A&M University College StationUSA
  2. 2.Department of Biomedical EngineeringTexas A&M University College StationUSA

Personalised recommendations