Abstract
The rate of fracture of Nitinol stents in the superficial femoral artery (SFA) is higher than desirable. Development of more fracture-resistant stents requires a better understanding of in-vivo loads, how stents deform under these loads, and the influence of the artery on stent deformation. In the work reported here, testing devices were designed and constructed to measure loads in stents undergoing tensile, bending, and torsional deformations. Tests to measure mechanical stiffnesses were performed on stents, mock arteries, and stents emplaced in mock arteries. Significant stent/artery interaction was observed under tension and bending; little interaction occurred under torsion loads. The results are explained by changes in stent geometry under load. The deformation, load, and stent/artery interaction information will be useful in validating finite element codes for designing and analyzing stents.
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References
Allie DE, Hebert CJ, Walker CM (2004) Nitinol stent fractures in the SFA. Endovasc Today 7:22–34
Scheinert D et al (2005) Prevalence and clinical impact of stent fractures after femoropopliteal stenting. J Am Coll Cardiol 45:312–315. doi:10.1016/j.jacc.2004.11.026
Smouse HB, Nikanorov A, LaFlash D (2004) Changes in major peripheral arteries during joint movement before and after stent placement in the cadaver model. In: Program and Abstracts, Transcatheter Cardiovascular Therapeutics, Washington, D.C., 27 Sep-4 Oct
Cheng CP, Wilson NM, Herfkens RJ, Taylor CA (2005) Superficial femoral artery deformations due to maximal hip and knee flexion: implications for stent design. In:13th International Society for Magnetic Resonance in Medicine, Miami, FL, 3–5 May
Stoeckel D, Pelton A, Duerig T (2004) Self-expanding Nitinol stents: material and design considerations. Eur Radiol 14:292–301. doi:10.1007/s00330-003-2022-5
SMST-2007: Proceedings of the International Conference on Shape Memory and Superelastic Technology (2007) Miyazaki, S (ed.), Tsukuba City, Japan, 3–5 December
McNaney JM, Imbeni V, Jung Y, Papadopoulos P, Ritchie RO (2003) An experimental study of the superelastic effect in a shape-memory Nitinol alloy under biaxial loading. Mech Mater 35(10):969–986
Perry KE, Labossiere PE, Steffler E (2007) Measurement of deformation and strain in Nitinol. Exp Mech 47(3):373–380
Robertson SW, Ritchie RO (2007) In vitro fatigue–crack growth and fracture toughness behavior of thin-walled superelastic Nitinol tube for endovascular stents: a basis for defining the effect of crack-like defects. Biomater 28(4):700–709
McKelvey AL, Ritchie RO (2001) Fatigue–crack growth behavior in the superelastic and shape-memory alloy Nitinol. Metall Mater Trans A 32A:731–743
Pelton AR, Schroedera V, Mitchell MR, Gong XY, Barneya M, Robertson SW (2008) Fatigue and durability of Nitinol stents. J Mech Behav Biomed Mat 1(2):153–164
Shockey D (2004) RESIStent Program: Reliability Enhancement and Service Improvement for Stents. In: SRI International Web site. Available via http://www.sri.com/psd/fracture/stents.html. Accessed February 2010
Cheng CP, Wilson NM, Hallett RL, Herfkens RJ, Taylor CA (2006) In vivo MR angiographic quantification of axial and twisting deformations of the superficial femoral artery resulting from maximum hip and knee flexion. J Vasc Interv Radiol 17(6):979–987
Tang BT, Cheng CP, Draney MT, Wilson NM, Tsao PS, Herfkens RJ, Taylor CA (2006) Abdominal aortic hemodynamics in young healthy adults at rest and during lower limb exercise: quantification using image-based computer modeling. Am J Physiol Heart Circ Physiol 291:H668–H676
Zhu L, Bennett NR, Fahrig R (2006) Scatter correction method for X-ray CT using primary modulation: theory and preliminary results. IEEE Trans Med Imag 25(12):1573–1587
Fahrig R, Wen Z, Ganguly A, DeCrescenzo G, Rowlands JA, Stevens GM, Saunders RF, Pelc NJ (2005) Performance of a static-anode/flat-panel X-ray fluoroscopy system in a diagnostic strength magnetic field: a truly hybrid X-ray/MR imaging system. Med Phys 32(6):1775–1784
Simons JW, Shockey DA (2006) Mechanical testing devices for characterizing stents. Presented at the 2006 SMST Conference, Pacific Grove, California, 7–11 May
Simons JW, Dalal A, Shockey DA (2007) Load-deflection behavior of bare and covered stents. 2007 SEM Annual Conference & Exposition, Springfield, Massachusetts, 3–6 June
Duerig T (2010) Personal communication. NDC, Fremont, CA
Ramesh R, Strope RR, Price KS, Conti JC (2005) Frequency dependent hysteresis of silicone and latex mock arteries used in stent testing. Biomed Sci Instrum 41:163–168
Cheng CP, Choi G, Herfkens RJ, Taylor CA (2010) The effect of aging on deformations of the superficial femoral artery resulting from hip and knee flexion: potential clinical implications. J Vasc Interv Radiol 21(2):195–202
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Simons, J.W., Dalal, A. & Shockey, D.A. Load-Deformation Behavior of Nitinol Stents. Exp Mech 50, 835–843 (2010). https://doi.org/10.1007/s11340-010-9341-7
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DOI: https://doi.org/10.1007/s11340-010-9341-7