A Comparison of Functional and Physical Properties of Self-Expanding Intracranial Stents [Neuroform3, Wingspan, Solitaire, Leo(+), Enterprise]

Abstract

Purpose: 5 self-expanding intracranial stents Neuroform (N), Wingspan (W), Solitaire (S), Leo(+) (L), and Enterprise (E) were subjected to an in vitro examination and comparison of their physical features and functional properties in order to better understand the clinical advantages and potential limitations of each device.

Material and Methods: The following features were examined for each stent: visual appearance, radial strength, wall apposition, bending stiffness, gator backing, kink resistance, ovalization, vessel wall coverage, cell size, ease of delivery.

Results: Given are rankings for the 5 stents: radial force at 50% oversizing: L<N<E<S<W; radial force at 15% oversizing L<E<S<N<W; wall apposition: E<N=W<S; bending stiffness: N<L<W<S<E; gator backing: N and W only; kink resistance: N=W<E<S<L; ovalization: W<L<S<N<E; vessel wall coverage: S<E<N<W<L; cell size: L<W<E<N<S; ease of delivery: W<N<L<E<S. A comparative analysis of the in vitro test results with the clinical experience of the authors is presented in this paper.

Conclusion: The 5 stents have fundamentally different features and there is no stent that is superior in all tested aspects. The selection in an individual treatment should be based on clinical and technical requirements.

stents - Neuroform - Wingspan - Solitaire - Leo+ - Enterprise

References

• 1 Fernandez Zubillaga A, Guglielmi G, Viñuela F. et al . Endovascular occlusion of intracranial aneurysms with electrically detachable coils: correlation of aneurysm neck size and treatment results.  AJNR Am J Neuroradiol. 1994;  15 815-820
• 2 Higashida RT, Smith W, Gress D. et al . Intravascular stent and endovascular coil placement for a ruptured fusiform aneurysm of the basilar artery. Case report and review of the literature.  J Neurosurg. 1997;  87 944-949
• 3 Solymosi L, Chapot R, Bendszus M. Stent, balloon, or clip? The problem of wide-necked aneurysms.  Clin Neuroradiol. 2005;  15 145-160
• 4 Henkes H, Bose A, Felber S. et al . Endovascular coil occlusion of intracranial aneurysms assisted by a novel self-expandable nitinol microstent (Neuroform).  Intervent Neuroradiol. 2002;  8 107-119
• 5 Henkes H, Miloslavski E, Lowens S. et al . Treatment of intracranial atherosclerotic stenoses with balloon dilatation and self-expanding stent deployment (Wingspan).  Neuroradiology. 2005;  47 222-228
• 6 Henkes H, Flesser A, Brew S. et al . A novel microcatheter-delivered, highly-flexible and fully-retrievable stent, specifically designed for intracranial use Technical note.  Intervent Neuroradiol. 2003;  9 391-393
• 7 Liebig T, Henkes H, Reinartz J. et al . A novel self-expanding fully retrievable intracranial stent (SOLO): experience in nine procedures of stent-assisted aneurysm coil occlusion.  Neuroradiology. 2006;  48 471-478
• 8 Lubicz B, Francois O, Levivier M. et al . Preliminary experience with the enterprise stent for endovascular treatment of complex intracranial aneurysms: potential advantages and limiting characteristics.  Neurosurgery. 2008;  62 1063-1069
• 9 Mocco J, Snyder KV, Albuquerque FC. et al . Treatment of intracranial aneurysms with the Enterprise stent: a multicenter registry.  J Neurosurg. 2009;  110 35-39
• 10 Kis B, Weber W, Berlit P. et al . Elective treatment of saccular and broad-necked intracranial aneurysms using a closed-cell nitinol stent (Leo).  Neurosurgery. 2006;  58 443-450
• 11 Duerig TW, Tolomeo DE, Wholey M. An overview of superelastic stent design.  Minim Invasive Ther Allied Technol. 2000;  9 235-246
• 12 Colombo A, Stankovic G, Moses JW. Selection of coronary stents.  J Am Coll Cardiol. 2002;  40 1021-1033
• 13 Siewiorek GM, Finol EA, Wholey MH. Clinical significance and technical assessment of stent cell geometry in carotid artery stenting.  J Endovasc Ther. 2009;  16 178-188
• 14 Lylyk P, Ferrario A, Pasbon B. et al . Buenos Aires experience with the Neuroform self-expanding stent for the treatment of intracranial aneurysms.  J Neurosurg. 2005;  102 235-241
• 15 Ansari SA, Lassig JP, Nicol E. et al . Thrombosis of a fusiform intracranial aneurysm induced by overlapping neuroform stents: case report.  Neurosurgery. 2007;  60 E950-E951
• 16 Fiorella D, Albuquerque FC, Masaryk TJ. et al . Balloon-in-stent technique for the constructive endovascular treatment of “ultra-wide necked” circumferential aneurysms.  Neurosurgery. 2005;  57 1218-1227
• 17 Lopes D, Sani S. Histological postmortem study of an internal carotid artery aneurysm treated with the Neuroform stent.  Neurosurgery. 2005;  56 E416
• 18 Turk AS, Niemann DB, Ahmed A. et al . Use of self-expanding stents in distal small cerebral vessels.  AJNR Am J Neuroradiol. 2007;  28 533-536
• 19 Radaelli AG, Augsburger L, Cebral JR. et al . Reproducibility of haemodynamical simulations in a subject-specific stented aneurysm model − a report on the Virtual Intracranial Stenting Challenge 2007.  J Biomech. 2008;  41 2069-2081
• 20 Cantón G, Levy DI, Lasheras JC. et al . Flow changes caused by the sequential placement of stents across the neck of sidewall cerebral aneurysms.  J Neurosurg. 2005;  103 891-902
• 21 Henkes H, Reinartz J, Preiss H. et al . Endovascular treatment of small intracranial aneurysms: three alternatives to coil occlusion.  Minim Invas Neurosurg. 2006;  49 65-69
• 22 Benndorf G, Claus B, Strother CM. et al . Increased cell opening and prolapse of struts of a neuroform stent in curved vasculature: value of angiographic computed tomography: technical case report.  Neurosurgery. 2006;  58 (4 Suppl 2) ONS-E380
• 23 Benndorf G, Ionescu M, Valdivia y, Alvarado M. et al . Anomalous hemodynamic effects of a self-expanding intracranial stent: comparing in-vitro and ex-vivo models using ultra-high resolution microCT based CFD.  J Biomech. 2010;  43 740-748
• 24 Ebrahimi N, Claus B, Lee CY. et al . Stent conformity in curved vascular models with simulated aneurysm necks using flat-panel CT: an in vitro study.  AJNR Am J Neuroradiol. 2007;  28 823-829
• 25 Hsu SW, Chaloupka JC, Feekes JA. et al . In vitro studies of the Neuroform microstent using transparent human intracranial arteries.  AJNR Am J Neuroradiol. 2006;  27 1135-1139
• 26 Fiorella D, Albuquerque FC, Deshmukh VR. et al . Usefulness of the Neuroform stent for the treatment of cerebral aneurysms: results at initial (3-6-mo) follow-up.  Neurosurgery. 2005;  56 1191-1201
• 27 Fiorella D, Albuquerque FC, Woo H. et al . Neuroform in-stent stenosis: incidence, natural history, and treatment strategies.  Neurosurgery. 2006;  59 34-42
• 28 Hoit DA, Malek AM. Three-dimensional rotational angiographic detection of in-stent stenosis in wide-necked aneurysms treated with a self-expanding intracranial stent.  Neurosurgery. 2005;  57 1228-1236
• 29 Fiorella D, Albuquerque FC, Deshmukh VR. et al . In-stent stenosis as a delayed complication of neuroform stent-supported coil embolization of an incidental carotid terminus aneurysm.  AJNR Am J Neuroradiol. 2004;  25 1764-1767
• 30 Henkes H, Kirsch M, Mariushi W. et al . Coil treatment of a fusiform upper basilar trunk aneurysm with a combination of “kissing” Neuroform stents, TriSpan-, 3D- and fibered coils, and permanent implantation of the microguidewires.  Neuroradiology. 2004;  46 464-468
• 31 Thorell WE, Chow MM, Woo HH. et al . Y-configured dual intracranial stent-assisted coil embolization for the treatment of wide-necked basilar tip aneurysms.  Neurosurgery. 2005;  56 1035-1040
• 32 Yavuz K, Geyik S, Saatci I. et al . WingSpan stent system in the endovascular treatment of intracranial aneurysms: clinical experience with midterm follow-up results.  J Neurosurg. 2008;  109 445-453
• 33 Turk AS, Levy EI, Albuquerque FC. et al . Influence of patient age and stenosis location on Wingspan in-stent restenosis.  AJNR Am J Neuroradiol. 2008;  29 23-27
• 34 Kim M, Levy EI, Meng H. et al . Quantification of hemodynamic changes induced by virtual placement of multiple stents across a wide-necked basilar trunk aneurysm.  Neurosurgery. 2007;  61 1305-1312
• 35 Klisch J, Eger C, Sychra V. et al . Stent-assisted coil embolization of posterior circulation aneurysms using Solitaire AB: preliminary experience.  Neurosurgery. 2009;  65 258-266
• 36 Lubicz B, Leclerc X, Levivier M. et al . Retractable self-expandable stent for endovascular treatment of wide-necked intracranial aneurysms: preliminary experience.  Neurosurgery. 2006;  58 451-457
• 37 Valdivia y, Alvarado M, Ebrahimi N, Benndorf G.. Study of conformability of the new Leo plus stent to a curved vascular model using flat-panel detector computed tomography (DynaCT).  Neurosurgery. 2009;  64 130-134
• 38 Pumar JM, Lete I, Pardo MI. et al . Leo stent monotherapy for the endovascular reconstruction of fusiform aneurysms of the middle cerebral artery.  AJNR Am J Neuroradiol. 2008;  29 1775-1776
• 39 Peluso JP, van Rooij WJ, Sluzewski M. et al . A new self-expandable nitinol stent for the treatment of wide-neck aneurysms: initial clinical experience.  AJNR Am J Neuroradiol. 2008;  29 1405-1408
• 40 Lavine SD, Meyers PM, Connolly ES. et al . Spontaneous delayed proximal migration of enterprise stent after staged treatment of wide-necked basilar aneurysm: technical case report.  Neurosurgery. 2009;  64 E1012
• 41 Benndorf G, Ionescu M, YA MV. et al . Wall shear stress in intracranial self-expanding stents studied using ultra-high-resolution 3D reconstructions.  AJNR Am J Neuroradiol. 2009;  30 479-486
• 42 Lopes DK, Wells K. Stent remodeling technique for coiling of ruptured wide-neck cerebral aneurysms: case report.  Neurosurgery. 2009;  65 E1007-E1008

Correspondence