Effects of metal coverage rate of flow diversion device on neointimal growth at side branch ostium and stented artery: an animal experiment in rabbit abdominal aorta

IntroductionTo access the effect of actual metal coverage rate (MCR) on neointimal growth at covered side branch ostium and stented artery after implantation of a flow diversion device.MethodsFlow diverters (FDs) were implanted into abdominal aortas of 20 New Zealand rabbits. Four weeks and three months after FD implantation, the patency of side branches covered by the devices was assessed by angiography. The animals were sacrificed after angiography at 3 months postsurgery. The local actual MCR was measured under microscope and calculated. The extent of neointimal coverage at the ostia of branches and the neointima within the stent were examined by histology and scanning electron microscopy.ResultsNo side branch occlusion was noted, either immediately after implantation or at follow-ups. At 3 months after implantation, the intimal coverage of branch ostia caused by a 30–40% MCR was not significantly different from that caused by an MCR ≤ 30% (p = 0.792), but it was significantly lower than that caused by an MCR ≥ 40% (p = 0.021). Neointimal thickness in the stented abdominal aorta was positively correlated to MCR (r = 0.523, p = 0.001). The neointima was composed predominantly of smooth muscle cells and collagen fibers.ConclusionThe actual MCR exhibited remarkable differences once FD was implanted in vivo. Significantly more intimal coverage at the side branch ostia could be induced when MCR was ≥40%. The neointimal thickness within the stent was positively correlated to device MCR.

[1]  Baruch B. Lieber,et al.  Particle Image Velocimetry Assessment of Stent Design Influence on Intra-Aneurysmal Flow , 2002, Annals of Biomedical Engineering.

[2]  A study of the first-generation pipeline embolization device morphology using intraoperative angiographic computed tomography (ACT) , 2010, Neuroradiology.

[3]  T. Liou,et al.  Hemodynamics altered by placing helix stents in an aneurysm at a 45 degrees angle to the curved vessel. , 2008, Physics in medicine and biology.

[4]  M. Sluzewski,et al.  Perforator Infarction after Placement of a Pipeline Flow-Diverting Stent for an Unruptured A1 Aneurysm , 2010, American Journal of Neuroradiology.

[5]  David F. Kallmes,et al.  A New Endoluminal, Flow-Disrupting Device for Treatment of Saccular Aneurysms , 2007, Stroke.

[6]  Jacqueline Birks,et al.  Risk of recurrent subarachnoid haemorrhage, death, or dependence and standardised mortality ratios after clipping or coiling of an intracranial aneurysm in the International Subarachnoid Aneurysm Trial (ISAT): long-term follow-up , 2009, The Lancet Neurology.

[7]  Baruch B. Lieber,et al.  Angiographic Assessment of the Performance of Flow Divertors to Treat Cerebral Aneurysms , 2006, 2006 International Conference of the IEEE Engineering in Medicine and Biology Society.

[8]  N. Stergiopulos,et al.  Effect of Flow Diverter Porosity on Intraaneurysmal Blood Flow , 2009, Clinical Neuroradiology.

[9]  J. Pruvo,et al.  Flow-Diverter Stent for the Endovascular Treatment of Intracranial Aneurysms: A Prospective Study in 29 Patients With 34 Aneurysms , 2010, Stroke.

[10]  Isabel Wanke,et al.  High-Profile Flow Diverter (Silk) Implantation in the Basilar Artery: Efficacy in the Treatment of Aneurysms and the Role of the Perforators , 2010, Stroke.

[11]  P. Sandercock,et al.  International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised comparison of effects on survival, dependency, seizures, rebleeding, subgroups, and aneurysm occlusion , 2005, The Lancet.

[12]  Stephen Rudin,et al.  The Asymmetric Vascular Stent: Efficacy in a Rabbit Aneurysm Model , 2009, Stroke.

[13]  E. Edelman,et al.  Pathobiologic responses to stenting. , 1998, The American journal of cardiology.

[14]  Liliana Cesar,et al.  An Original Flow Diversion Device for the Treatment of Intracranial Aneurysms: Evaluation in the Rabbit Elastase-Induced Model , 2009, Stroke.

[15]  Bernd F. M. Romeike,et al.  Treatment of wide-necked intracranial aneurysms with a novel self-expanding two-zonal endovascular stent device , 2007, Neuroradiology.

[16]  Z Kulcsar,et al.  Treatment of Intracranial Aneurysms by Functional Reconstruction of the Parent Artery: The Budapest Experience with the Pipeline Embolization Device , 2010, American Journal of Neuroradiology.

[17]  Hui Meng,et al.  Comparison of Two Stents in Modifying Cerebral Aneurysm Hemodynamics , 2008, Annals of Biomedical Engineering.

[18]  T. Liou,et al.  Effects of stent porosity on hemodynamics in a sidewall aneurysm model. , 2008, Journal of biomechanics.

[19]  A. Molyneux,et al.  International Subarachnoid Aneurysm Trial (ISAT) of Neurosurgical Clipping Versus Endovascular Coiling in 2143 Patients With Ruptured Intracranial Aneurysms: A Randomised Comparison of Effects on Survival, Dependency, Seizures, Rebleeding, Subgroups, and Aneurysm Occlusion , 2005 .

[20]  Chander Sadasivan,et al.  Endoluminal scaffolds for vascular reconstruction and exclusion of aneurysms from the cerebral circulation. , 2010, Stroke.

[21]  Z Kulcsar,et al.  The Potential of Flow Modification in the Treatment of Intracranial Aneurysms , 2008, Interventional neuroradiology : journal of peritherapeutic neuroradiology, surgical procedures and related neurosciences.

[22]  R. Blanc,et al.  An in vitro study of silk stent morphology , 2011, Neuroradiology.

[23]  D. Fiorella,et al.  CURATIVE RECONSTRUCTION OF A GIANT MIDBASILAR TRUNK ANEURYSM WITH THE PIPELINE EMBOLIZATION DEVICE , 2009, Neurosurgery.

[24]  H. Woo,et al.  DEFINITIVE RECONSTRUCTION OF CIRCUMFERENTIAL, FUSIFORM INTRACRANIAL ANEURYSMS WITH THE PIPELINE EMBOLIZATION DEVICE , 2008 .

[25]  Jason Sherman,et al.  Angiographic analysis of animal model aneurysms treated with novel polyurethane asymmetric vascular stent (P-AVS): feasibility study , 2009, Medical Imaging.

[26]  Stephen Rudin,et al.  Asymmetric Vascular Stent: Feasibility Study of a New Low-Porosity Patch-Containing Stent , 2008, Stroke.

[27]  A. Becker,et al.  Neointimal tissue response at sites of coronary stenting in humans: macroscopic, histological, and immunohistochemical analyses. , 1998, Circulation.

[28]  Baruch B. Lieber,et al.  Treatment of Rabbit Elastase-Induced Aneurysm Models by Flow Diverters: Development of Quantifiable Indexes of Device Performance Using Digital Subtraction Angiography , 2009, IEEE Transactions on Medical Imaging.

[29]  I. Wanke,et al.  Effect of Flow Diversion Treatment on Very Small Ruptured Aneurysms , 2010, Neurosurgery.

[30]  Jaehoon Seong,et al.  In vitro evaluation of flow divertors in an elastase-induced saccular aneurysm model in rabbit. , 2007, Journal of biomechanical engineering.

[31]  A. Wakhloo,et al.  Alteration of hemodynamics in aneurysm models by stenting: Influence of stent porosity , 1997, Annals of Biomedical Engineering.

[32]  D F Kallmes,et al.  A Second-Generation, Endoluminal, Flow-Disrupting Device for Treatment of Saccular Aneurysms , 2009, American Journal of Neuroradiology.

[33]  Kyehan Rhee,et al.  Changes of Flow Characteristics by Stenting in Aneurysm Models: Influence of Aneurysm Geometry and Stent Porosity , 2002, Annals of Biomedical Engineering.

[34]  Carlos Miranda,et al.  CURATIVE ENDOVASCULAR RECONSTRUCTION OF CEREBRAL ANEURYSMS WITH THE PIPELINE EMBOLIZATION DEVICE: THE BUENOS AIRES EXPERIENCE , 2009, Neurosurgery.