Finanziamento Il presente studio è stato sostenuto dal fondo di ricerca Falk per il Dipartimento di Chirurgia cardiotoracica della Stanford University School of Medicine, Stanford, CA, USA. Tobias Deuse è stato finanziato da una borsa di studio della Società Tedesca cardiaca. Sonja Schrepfer ha ricevuto un assegno di ricerca dalla Deutsche Forschungsgemeinschaft (DFG) (SCHR992/2-1).

Aortica distribuzione stent <ol><li> Maschi Sprague-Dawley di peso 550-600 g sono acquistati da Harlan (Indianapolis, IN, USA). Ratti casa in condizioni convenzionali, alimentati standard di ratto cibo e acqua ad libitum. </li><li> Anestetizzare ratto con isoflurano (2%) e ketamina (25 mg / kg). In vista microscopico, eseguire una media superiore mini-laparotomia per esporre l&#39;aorta sottorenale. </li><li> Sezionare l&#39;aorta addominale dal tessuto circostante, dal livello delle arterie renali fino alla biforcazione. ATTENZIONE: Non c&#39;è bisogno di sezionare l&#39;aorta dalla IVC. </li><li> Usa microclamps per fermare il flusso aortico sangue. Posizionare il morsetto prossimale per primo, seguito dal morsetto distale. </li><li> Aprire l&#39;aorta con una piccola incisione trasversale e lavare l&#39;aorta con eparina (200 unità). </li><li> L&#39;endotelio aortico è denudato dal passaggio di un 2-francese catetere Fogarty embolectomia arteriosa (Baxter Healthcare, Deerfield, IL, USA). </li><li> Utilizzare qualsiasi dimensione umana stent tra 8mm e 12mm di lunghezza e 2,5 mm-3mm di diametro. ATTENZIONE: Il diametro dello stent non dovrebbe superare il diametro del vaso di oltre il 10% per evitare stenosi pre-e post-stent. ATTENZIONE: Non accendere la lunghezza dello stent all&#39;interno dello studio stesso. </li><li> Distribuire lo stent con palloncino alla pressione appropriata per ottenere il diametro desiderato. </li><li> L&#39;incisione aortica piccolo si chiude con 9-0 punti di sutura Prolene (Ethicon, Norderstedt, Germania). </li><li> Chiudere l&#39;incisione addominale a strati con 4-0 punti di sutura Vicryl esecuzione (Ethicon, Norderstedt, Germania). Le suture cutanee devono ancora essere rimosse entro 7-14 giorni, anche quando Viacryl viene utilizzato. </li><li> Animali ricevuto Carprofen (6mg/kg) durante l&#39;intervento, e Metamizol per 7 giorni in più in acqua potabile. </li></ol> Optical Coherence Tomography (OCT) Imaging Immagini ottobre si ottengono con i PTOM M2 sistema di imaging (Lightlab Imaging, Inc., Westford, MA, USA). ImageWire è una sonda di imaging per fornire la luce al tessuto e raccogliere i segnali. Il ImageWire composto da 0,006 &quot;(0,15 mm) in fibra ottica core, all&#39;interno di una guaina con un diametro esterno massimo di 0,019&quot; (0,48 mm). <ol><li> Anestetizzare ratto con isoflurano (2%) e ketamina (25 mg / kg). In vista microscopico, eseguire una laparotomia mediana rifare per esporre l&#39;aorta sottorenale. </li><li> Morsetto l&#39;aorta prossimale ed entrambi arteria iliaca. </li><li> Eseguire una arteriotomia trasversale alla fine distale dell&#39;aorta, a filo con 1ml PBS utilizzando un catetere 28G e inserire il catetere ottobre e lo trasmette nell&#39;aorta. </li><li> Motorizzato pullback ottobre l&#39;imaging viene effettuata ad un tasso pullback di 1,0 mm al secondo. </li><li> Acquisire immagini a 15 fotogrammi al secondo, le immagini vengono visualizzate con una tabella di colori di look-up e archiviati in formato digitale. </li><li> Chiudere il arteriotomia. </li><li> Chiudere l&#39;addominale e incisioni con 4-0 punti di sutura Vicryl esecuzione (Ethicon, Norderstedt, Germania). Le suture cutanee devono ancora essere rimosse entro 7-14 giorni, anche quando Viacryl viene utilizzato. </li><li> La formazione si svilupperà neointima massimo entro 6 settimane dopo l&#39;impianto dello stent. </li></ol> Analizzando le immagini Ottobre Misure ottobre vengono eseguite utilizzando il software proprietario Lightlab ottobre imaging con un topo-based. <ol><li> Calibrare il sistema alla riflessione del filo ottobre imaging, che è la tecnica standard di calibrazione per questo sistema. </li><li> Traccia lume dello stent e aree delle sezioni trasversali (CSA) manualmente ad ogni intervallo 1,0 mm. </li><li> Calcolare l&#39;area trasversale della placca come CSA stent sottratto dal CSA lume. Calcolare placca zona per cento CSA placca diviso per CSA stent (%). Calcolare la media aree placca per cento. </li></ol> Validazione della tecnica di ottobre Risultati Ottobre correlano bene con l&#39;istopatologia (Figura 1). CSA placca istologici sono calcolati come sopra descritto. L&#39;istologia rivela iperplasia intimale con alta densità di cellule fusiformi e solo poche cellule mononucleate infiammazione. Dopo 6 settimane, gli stent sono interamente rivestiti con tessuto di granulazione neointimale e il CSA placca misure di 1,3 ± 0,4 mm 2 in uno stent da 2,5 mm. <img src="/files/ftp_upload/1346/1346fig1tmb.jpg" border="0" /> Figura 1: Ottobre (A) e istologiche (B, ingrandimento 16x) le immagini dello stent 6 settimane dopo la distribuzione. Risultati ottenuti da CSA placca immagini Ottobre correlano bene con l&#39;istopatologia. Si prega di <a href="https://www.jove.com/files/ftp_upload/1346/1346fig1.jpg">cliccare qui</a> per vedere una versione più grande della figura 1.

<ol>
	<li>Langeveld, B., Roks, A. J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Commentary:+rat+restenosis+models:+means+for+thorough+restenosis+research.">Commentary: rat restenosis models: means for thorough restenosis research.</a> Journal of endovascular therapy. 12 (3), 343-345 (2005).</li><li>Roguin, A., Grenadier, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stent-based+percutaneous+coronary+interventions+in+small+coronary+arteries.">Stent-based percutaneous coronary interventions in small coronary arteries.</a> Acute Card Care. 8, 70-74 (2006).</li><li>Post, M. J., Waltenberger, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+Is+Beautiful:+A+Miniature+Stent+Model.">Small Is Beautiful: A Miniature Stent Model.</a> Arterioscler. Thromb. Vasc. Biol. 27, 701-702 (2007).</li><li>Langeveld, B., Roks, A. J. M., Tio, R. A., Boven, A. J. v. a. n., Want, J. J. L. v. a. n. d. e. r., Henning, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rat+abdominal+aorta+stenting:+a+new+and+reliable+small+animal+model+for+in-stent+restenosis.">Rat abdominal aorta stenting: a new and reliable small animal model for in-stent restenosis.</a> Journal of vascular research. 41 (5), 377-386 (2004).</li><li>Lowe, H. C., Chesterman, C. N., Khachigian, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rat+aortic+stenting:+toward+a+simple+model+of+in-stent+restenosis.">Rat aortic stenting: toward a simple model of in-stent restenosis.</a> The American journal of cardiology. 88 (6), 720-721 (2001).</li><li>Groenewegen, R., Harst, R. v. a. n. d. e. r., Roks, R., Buikema, R., Zijlstra, R., Gilst, R. v. a. n. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+angiotensin+II+and+angiotensin+II+type+1+receptor+blockade+on+neointimal+formation+after+stent+implantation.">Effects of angiotensin II and angiotensin II type 1 receptor blockade on neointimal formation after stent implantation.</a> International Journal of Cardiology. , (2007).</li><li>de Smet, B. J. G. L., Zijlstra, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+look+at+drug+eluting+stents+with+optical+coherence+tomography.">A look at drug eluting stents with optical coherence tomography.</a> European Heart Journal. 28 (8), 918-919 (2007).</li><li>Pinto, T. L., Waksman, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+applications+of+optical+coherence+tomography.">Clinical applications of optical coherence tomography.</a> Journal of interventional cardiology. 19 (6), 566-573 (2006).</li><li>Matsumoto, D., Shite, J., Shinke, T., Otake, H., Tanino, Y., Ogasawara, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neointimal+coverage+of+sirolimus-eluting+stents+at+6-month+follow-up:+evaluated+by+optical+coherence+tomography.">Neointimal coverage of sirolimus-eluting stents at 6-month follow-up: evaluated by optical coherence tomography.</a> European Heart Journal. 28 (8), 961-967 (2007).</li><li>Kawase, Y., Suzuki, Y., Ikeno, F., Yoneyama, R., Hoshino, K., Ly, H. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+nonuniform+rotational+distortion+between+mechanical+IVUS+and+OCT+using+a+phantom+model.+Ultrasound+in+medicine+&amp;amp;+biology.">Comparison of nonuniform rotational distortion between mechanical IVUS and OCT using a phantom model. Ultrasound in medicine &amp;amp; biology.</a> 33 (1), 67-73 (2007).</li></ol>

Tutti i ratti sono stati ospitati nella struttura cura degli animali presso la Stanford University Medical Center (Stanford, Ca), alla temperatura standard, umidità e condizioni di illuminazione, e sono stati forniti ratto cibo e acqua ad libitum. L&#39;indagine conforme alla Guida per la cura e l&#39;uso di animali da laboratorio pubblicato dal National Institutes of Health (NIH pubblicazione n ° 85-23, riveduta nel 1996). Il protocollo dello studio è stato approvato dal gruppo amministrativa per la cura degli animali da laboratorio, la Stanford University.

Anche se l&#39;arteria iliaca coniglio e maiale i modelli delle arterie coronarie sono le più frequentemente utilizzate per il posizionamento dello stent 1, una combinazione di radiologia e di attrezzature chirurgiche è richiesto, capacità di alloggiamento animale è limitata, ed i costi di acquisto sono elevati. Limiti del modello di ratto stent è necessario l&#39;uso di stent progettato specificamente per i ratti, il metallo-arteria rapporto con conseguente più danno vascolare 2, e l&#39;incidenza artificialmente elevato di trombosi 3. Il modello di stenting ratto è un 4 semplice, economico, rapido e accurato modello preclinico. Dopo la relazione iniziale di stenting diretto dell&#39;aorta ratto da Lowe et al. 5, fattibilità e l&#39;idoneità di questo modello per la valutazione della fisiopatologia della ristenosi in-stent è stato completamente dimostrato 5,6. Il diametro dell&#39;aorta ratto è sufficiente per consentire l&#39;espansione degli stent disponibili in commercio senza interruzioni dell&#39;architettura nave fisiologico. E &#39;stato dimostrato che i meccanismi fisiopatologici, come la formazione di trombi, l&#39;infiammazione e la proliferazione SMC, si sviluppano in questi modelli di ratto come fanno nel coniglio e maiale. Di conseguenza, questi modelli sono rappresentazioni bene il processo reale di ristenosi. L&#39;alta risoluzione ottobre tecnologia di imaging è utile per valutare iperplasia intimale. La profondità di penetrazione è solo 1,5-2 mm, ma la sua risoluzione è un ordine di grandezza superiore a quella degli ultrasuoni intravascolari (IVUS) 7,8. Diversi studi a confronto con ottobre IVUS concludere che ottobre è attualmente la tecnica preferita per valutare iperplasia neointimale dopo 8-10 impianto di stent. Soprattutto nei piccoli animali con diametri dei piccoli vasi, l&#39;alta risoluzione di Ottobre lo rende migliore la modalità di imaging per la valutazione della ristenosi. In sintesi, questo video mostra che (1) aortica stenting ratto è facilmente fattibile, (2) stent aorta addominale di ratto è adatto per i test stent fabbricato industrialmente e (3) Ottobre imaging è una tecnica precisa ed elegante per il monitoraggio longitudinale di in-stent ristenosi.

imaging in-stent restenosis: an inexpensive, reliable, and rapid preclinical model

Modelli preclinici di restenosi sono essenziali per svelare i processi fisiopatologici che conducono alla ristenosi in-stent e per ottimizzare esistenti e futuri stent medicati. Una varietà di anticorpi e di ceppi transgenici e knockout sono disponibili nei ratti. Di conseguenza, un modello per la ristenosi in-stent nel ratto sarebbe conveniente per gli studi pathobiological e fisiopatologici. In questo video, vi presentiamo l&#39;intera procedura e tranelli di un modello di topo stent adatto per ricerca di alta velocità dello stent. Mostreremo la procedura chirurgica di stent, e la valutazione della ristenosi in-stent con la tecnica più elegante di OCT (Optical Coherence Tomography). Questa tecnica assicura un&#39;elevata precisione nella valutazione CSA placca (zone di sezione trasversale) e si correla bene con le sezioni istologiche, che richiedono tecniche speciali che consumano tempo e embedding e sezionamento. Ottobre di imaging consente inoltre il monitoraggio longitudinale dello sviluppo della ristenosi in-stent all&#39;interno dello stesso animale in confronto a un tempo istantanee con istologia.

Watch this Scientific Journal Video about Imaging In-Stent Restenosis: An Inexpensive, Reliable, and Rapid Preclinical Model at JoVE.com

Imaging In-Stent Restenosis: An Inexpensive, Reliable, and Rapid Preclinical Model

Questo video illustra come utilizzare un modello preclinico economico e affidabile per lo studio dei processi fisiopatologici pathobiological e di sviluppo in-stent restenosi. Longitudinale monitoraggio in vivo utilizzando OCT (Optical Coherence Tomography) e l&#39;analisi delle immagini Ottobre sono anche dimostrato.

Imaging ristenosi in-stent: un poco costoso, modello affidabile, rapido e preclinici

Preclinical models of restenosis are essential to unravel the pathophysiological processes that lead to in-stent restenosis and to optimize existing and ...

imaging-stent-restenosis-an-inexpensive-reliable-rapid-preclinical

Research

JoVE Journal

Biology

13.8K Views.  Stanford University School of Medicine. Questo video illustra come utilizzare un modello preclinico economico e affidabile per lo studio dei processi fisiopatologici pathobiological e di sviluppo in-stent restenosi. Longitudinale monitoraggio in vivo utilizzando OCT (Optical Coherence Tomography) e l'analisi delle immagini Ottobre sono anche dimostrato.

Video: Imaging In-Stent Restenosis: An Inexpensive, Reliable, and Rapid Preclinical Model

Monitoring the Wall Mechanics During Stent Deployment in a Vessel

Clinical trials have reported different restenosis rates for various stent designs1. It is speculated that stent-induced strain concentrations on the arterial wall lead to tissue injury, which initiates restenosis2-7. This hypothesis needs further investigations including better quantifications of non-uniform strain distribution on the artery following stent implantation. A non-contact surface strain measurement method for the stented artery is presented in this work. ARAMIS stereo optical surface strain measurement system uses two optical high speed cameras to capture the motion of each reference point, and resolve three dimensional strains over the deforming surface8,9. As a mesh stent is deployed into a latex vessel with a random contrasting pattern sprayed or drawn on its outer surface, the surface strain is recorded at every instant of the deformation. The calculated strain distributions can then be used to understand the local lesion response, validate the computational models, and formulate hypotheses for further in vivo study.

Stent-induced arterial strain distributions are characterized using an optical surface strain measurement system. This visualization technique is used to gain insights into the impact of stent implantation on the host vessel.

Monitoraggio dei Mechanics parete durante la distribuzione stent in un recipiente

Clinical trials have reported different restenosis rates for various stent designs1. It is speculated that stent-induced strain concentrations on the ...

Ricerca

Bioingegneria

Human Internal Mammary Artery (IMA) Transplantation and Stenting: A Human Model to Study the Development of In-Stent Restenosis

Preclinical in vivo research models to investigate pathobiological and pathophysiological processes in the development of intimal hyperplasia after vessel stenting are crucial for translational approaches1,2.
The commonly used animal models include mice, rats, rabbits, and pigs3-5. However, the translation of these models into clinical settings remains difficult, since those biological processes are already studied in animal vessels but never performed before in human research models6,7. In this video we demonstrate a new humanized model to overcome this translational gap. The shown procedure is reproducible, easy, and fast to perform and is suitable to study the development of intimal hyperplasia and the applicability of diverse stents.
This video shows how to perform the stent technique in human vessels followed by transplantation into immunodeficient rats, and identifies the origin of proliferating cells as human.

Human Internal Mammary Artery IMA Transplantation and Stenting: A Human Model to Study the Development of In-Stent Restenosis

This video shows a model to study the development of intimal hyperplasia after stent deployment using a human vessel (IMA) in an immunodeficient rat model.

Umano arteria mammaria interna (IMA) Trapianti e Stenting: un modello umano per studiare lo sviluppo della ristenosi in-stent

Preclinical in vivo research models to investigate pathobiological and pathophysiological processes in the development of intimal hyperplasia after vessel ...

Medicina

Retrograde Perfusion and Filling of Mouse Coronary Vasculature as Preparation for Micro Computed Tomography Imaging

Visualization of the vasculature is becoming increasingly important for understanding many different disease states. While several techniques exist for imaging vasculature, few are able to visualize the vascular network as a whole while extending to a resolution that includes the smaller vessels1,2. Additionally, many vascular casting techniques destroy the surrounding tissue, preventing further analysis of the sample3-5. One method which circumvents these issues is micro-Computed Tomography (&mu;CT). &mu;CT imaging can scan at resolutions &lt;10 microns, is capable of producing 3D reconstructions of the vascular network, and leaves the tissue intact for subsequent analysis (e.g., histology and morphometry)6-11. However, imaging vessels by ex vivo &mu;CT methods requires that the vessels be filled with a radiopaque compound. As such, the accurate representation of vasculature produced by &mu;CT imaging is contingent upon reliable and complete filling of the vessels. In this protocol, we describe a technique for filling mouse coronary vessels in preparation for &mu;CT imaging.
Two predominate techniques exist for filling the coronary vasculature: in vivo via cannulation and retrograde perfusion of the aorta (or a branch off the aortic arch) 12-14, or ex vivo via a Langendorff perfusion system 15-17. Here we describe an in vivo aortic cannulation method which has been specifically designed to ensure filling of all vessels. We use a low viscosity radiopaque compound called Microfil which can perfuse through the smallest vessels to fill all the capillaries, as well as both the arterial and venous sides of the vascular network. Vessels are perfused with buffer using a pressurized perfusion system, and then filled with Microfil. To ensure that Microfil fills the small higher resistance vessels, we ligate the large branches emanating from the aorta, which diverts the Microfil into the coronaries. Once filling is complete, to prevent the elastic nature of cardiac tissue from squeezing Microfil out of some vessels, we ligate accessible major vascular exit points immediately after filling. Therefore, our technique is optimized for complete filling and maximum retention of the filling agent, enabling visualization of the complete coronary vascular network &#x2013; arteries, capillaries, and veins alike.

Visualization of the coronary vessels is critical to advancing our understanding of cardiovascular diseases. Here we describe a method for perfusing murine coronary vasculature with a radiopaque silicone rubber (Microfil), in preparation for micro-Computed Tomography (&mu;CT) imaging.

Perfusione retrograda e riempimento del sistema vascolare coronarico mouse come preparazione per la Micro Computed Tomography Imaging

Visualization of the vasculature is becoming increasingly important for understanding many different disease states. While several techniques exist for ...

A Murine Model of Stent Implantation in the Carotid Artery for the Study of Restenosis

Despite the considerable progress made in the stent development in the last decades, cardiovascular diseases remain the main cause of death in western countries. Beside the benefits offered by the development of different drug-eluting stents, the coronary revascularization bears also the life-threatening risks of in-stent thrombosis and restenosis. Research on new therapeutic strategies is impaired by the lack of appropriate methods to study stent implantation and restenosis processes. Here, we describe a rapid and accessible procedure of stent implantation in mouse carotid artery, which offers the possibility to study in a convenient way the molecular mechanisms of vessel remodeling and the effects of different drug coatings.

A model of stent implantation in mouse carotid artery is described. Compared to other similar methods, this procedure is very rapid, simple and accessible, offering the possibility to study in a convenient way the vascular wall reaction to different drug-eluting stents and the molecular mechanisms of restenosis.

Un modello murino di impianto di stent a livello dell&#39;arteria carotidea per lo Studio della restenosi

Despite  the considerable progress made in the stent development in the last decades,  cardiovascular diseases remain the main cause of death in western ...

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD).

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

This method outlines the use of Quantum Micro-Computed Tomography (MicroCT) to assess cardiac morphology, function, perfusion, metabolism and viability with iodinated contrast agent in mice with experimentally-induced myocardial ischemia. The technique can be applied for non-destructive high-throughput longitudinal in vivo imaging of various animal models of human heart disease.

In Vivo quantitativa valutazione della struttura del miocardio, la funzione, la perfusione e sostenibilità Utilizzando cardiaca micro-tomografia computerizzata

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that ...

Induction of Accelerated Atherosclerosis in Mice: The "Wire-Injury" Model

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. Moreover, by rupture of the defective vascular wall, atherosclerosis induces occlusive thrombus formation, which represents the main cause of myocardial infarction or stroke and the most frequent cause of death. Despite the advances in the cardiovascular field, many questions remain unanswered, and additional basic research is essential to improve our understanding of the molecular mechanisms during atherosclerosis and its effects. Due to limited clinical studies, there is a need for representative animal models recreating atherosclerotic conditions such as neointima formation after stent implantation, balloon angioplasty, or endarterectomy. Since the mouse presents many advantages and is the most frequently used model for studying molecular processes, the current study proposes an invasive procedure of endothelial denudation, also known as the wire-injury model, which is representative of the human condition of neointima formation in arteries after revascularization procedures.

This study describes an invasive procedure for the induction of accelerated atherosclerosis in mice. In comparison to other methods using electric- or cryo-induced injury, mechanical-induced injury mimics the human condition of restenosis after revascularization therapies and is ideal for the study of the molecular mechanisms involved.

Induzione di aterosclerosi accelerata nei topi: il modello "Wire-Injury"

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. ...

Biodegradable Magnesium Stent Treatment of Saccular Aneurysms in a Rat Model - Introduction of the Surgical Technique

The steady progess in the armamentarium of techniques available for endovascular treatment of intracranial aneurysms requires affordable and reproducable experimental animal models to test novel embolization materials such as stents and flow diverters. The aim of the present project was to design a safe, fast, and standardized surgical technique for stent assisted embolization of saccular aneurysms in a rat animal model.
Saccular aneurysms were created from an arterial graft from the descending aorta.The aneurysms were microsurgically transplanted through end-to-side anastomosis to the infrarenal abdominal aorta of a syngenic male Wistar rat weighing &#62;500 g. Following aneurysm anastomosis, aneurysm embolization was performed using balloon expandable magnesium stents (2.5 mm x 6 mm). The stent system was retrograde introduced from the lower abdominal aorta using a modified Seldinger technique.
Following a pilot series of 6 animals, a total of 67 rats were operated according to established standard operating procedures. Mean surgery time, mean anastomosis time, and mean suturing time of the artery puncture site were 167 &#177; 22 min, 26 &#177; 6 min and 11 &#177; 5 min, respectively. The mortality rate was 6% (n=4). The morbidity rate was 7.5% (n=5), and in-stent thrombosis was found in 4 cases (n=2 early, n=2 late in stent thrombosis).
The results demonstrate the feasibility of standardized stent occlusion of saccular sidewall aneurysms in rats - with low rates of morbidity and mortality. This stent embolization procedure combines the opportunity to study novel concepts of stent or flow diverter based devices as well as the molecular aspects of healing.

Reproducable experimental animal models are needed for the testing of novel embolization materials, which have been designed to treat endovascular occlusion of intracranial aneurysms (IA). The present study aims to develop a safe and standardized surgical technique for stent assisted embolization of saccular aneurysms in a rat animal model.

Trattamento di Stent biodegradabili magnesio dei Aneurysms Saccular in un modello del ratto - introduzione della tecnica chirurgica

The steady progess in the armamentarium of techniques available for endovascular treatment of intracranial aneurysms requires affordable and reproducable ...

Neuroscienze

Novel Percutaneous Approach for Deployment of 3D Printed Coronary Stenosis Implants in Swine Models of Ischemic Heart Disease

Minimally invasive methods for creating models of focal coronary narrowing in large animals are challenging. Rapid prototyping using three-dimensionally (3D) printed coronary implants can be employed to percutaneously create a focal coronary stenosis. However, reliable delivery of the implants can be difficult without the use of ancillary equipment. We describe the use of a mother-and-child coronary guide catheter for stabilization of the implant and for effective delivery of the 3D printed implant to any desired location along the length of the coronary vessel. The focal coronary narrowing was confirmed under coronary cineangiography and the functional significance of the coronary stenosis was assessed using gadolinium-enhanced first-pass cardiac perfusion MRI. We showed that reliable delivery of 3D printed coronary implants in swine models (n = 11) of ischemic heart disease can be achieved through repurposing mother-and-child coronary guide catheters. Our technique simplifies the percutaneous delivery of coronary implants to create closed-chest swine models of focal coronary artery stenosis and can be performed expeditiously, with a low procedural failure rate.

We describe a novel, cost-effective, and efficient technique for percutaneous delivery of three-dimensionally printed coronary implants to create closed-chest swine models of ischemic heart disease. The implants were fixed in place using a mother-and-child extension catheter with high success rate.

Nuovo approccio percutaneo per la distribuzione di impianti coronarici stampati in 3D in modelli suini di malattie cardiache ischemiche

Minimally invasive methods for creating models of focal coronary narrowing in large animals are challenging. Rapid prototyping using three-dimensionally ...

Implantation of Human-Sized Coronary Stents into Rat Abdominal Aorta Using a Trans-Femoral Access

Percutaneous coronary intervention (PCI), combined with the deployment of a coronary stent, represents the gold standard in interventional treatment of coronary artery disease. In-stent restenosis (ISR) is determined by an excessive proliferation of neointimal tissue within the stent and limits the long-term success of stents. A variety of animal models have been used to elucidate pathophysiological processes underlying in-stent restenosis (ISR), with the porcine coronary and the rabbit iliac artery models being the most frequently used. Murine models provide the advantages of high throughput, ease of handling and housing, reproducibility, and a broad availability of molecular markers. The apolipoprotein E deficient (apoE-/- ) mouse model has been widely used to study cardiovascular diseases. However, stents must be miniaturized to be implanted into mice, involving important changes of their mechanical and (potentially) biological properties. The use of apoE-/- rats can overcome these shortcomings as apoE-/- rats allow for the evaluation of human-sized coronary stents while at the same time providing an atherogenic phenotype. This makes them an excellent and reliable model to investigate ISR after stent implantation. Here, we describe, in detail, the implantation of commercially available human coronary stents into the abdominal aorta of rats with an apoE-/- background using a trans-femoral access.

This protocol describes the implantation of human coronary stents into the abdominal aorta of rats with an apoE-/- background using a trans-femoral access. Compared with other animal models, murine models carry the advantages of high throughput, reproducibility, ease of handling and housing, and a broad availability of molecular markers.

Impianto di stent coronari di dimensioni umane nell'aorta addominale del ratto utilizzando un accesso trans-femorale

Percutaneous coronary intervention (PCI), combined with the deployment of a coronary stent, represents the gold standard in interventional treatment of ...

Preclinical Evaluation of Coronary Artery Stents

Coronary artery disease is a major contributor to morbidity and mortality worldwide. While lifestyle changes and medication are the cornerstones of treatment, coronary artery balloon angioplasty and stenting are routinely performed on patients with acute coronary syndromes and chronic coronary artery disease who remain symptomatic with optical medical treatment. Several generations of coronary stents have been developed over recent decades. Balloon angioplasty and stenting are supported by the use of pharmaceutical agents applied onto balloons and the stent surface, either to advance the healing properties of the artery post-intervention or to prevent the formation of restenosis. New devices need to be rigorously tested for safety and efficacy before acceptance into clinical practice; thus, there is a continuing need for reliable and reproducible preclinical methods of stent evaluation. We describe here a pig coronary artery model as well as an atherosclerotic rabbit model for coronary artery stent research and describe basic steps in intravascular imaging and stent histology.

New coronary artery stent designs and materials must be tested before clinical use in relevant preclinical models. Here we describe an atherosclerotic rabbit aorta model and a pig coronary artery model for stent research with in vivo and histological analyses.

Coronary artery disease is a major contributor to morbidity and mortality worldwide. While lifestyle changes and medication are the cornerstones of ...