The work was supported by the intramural research program of the NIH, National Institute on Aging, and by a Priority Research Centers Program grant from the National Research Foundation (NRF-2009-0093812) funded by the Ministry of Science, Information and Communication Technology, &amp; Future Planning, the Republic of Korea (H.T.). We thank Dr. Han-sol Park for putting "material" part together for the manuscript.

NOTE: the use of rat balloon injury model and associated procedures including injection of recombinant sRAGE and ultrasound sonographic studies have been approved by the Animal Care and Use Committee (ACUC) of National Institute on Aging, NIH.
1. Pre-surgery Preparations
<ol>
	<li>Instrument, Surgical Platform, and Personal Protection Equipment.
	<ol>
		<li>See Materials and Equipment&#39;s Table for all the surgical instruments and reagents used in this pro...

<ol>
	<li>Chaabane, C., Otsuka, F., Virmani, R., Bochaton-Piallat, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+responses+in+stented+arteries.">Biological responses in stented arteries.</a> Cardiovasc Res. 99, 353-363 (2013).</li><li>Goel, S. A., Guo, L. W., Liu, B., Kent, K. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+post-intervention+arterial+remodelling.">Mechanisms of post-intervention arterial remodelling.</a> Cardiovasc Res. 96, 363-371 (2012).</li><li>Khan, R., Agrotis, A., Bobik, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Understanding+the+role+of+transforming+growth+factor-beta1+in+intimal+thickening+after+vascular+injury.">Understanding the role of transforming growth factor-beta1 in intimal thickening after vascular injury.</a> Cardiovasc Res. 74, 223-234 (2007).</li><li>Schillinger, M., Minar, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Restenosis+after+percutaneous+angioplasty:+the+role+of+vascular+inflammation.">Restenosis after percutaneous angioplasty: the role of vascular inflammation.</a> Vasc Health Risk Manag. 1, 73-78 (2005).</li><li>Katz, G., Harchandani, B., Shah, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drug-eluting+stents:+the+past,+present,+and+future.">Drug-eluting stents: the past, present, and future.</a> Curr Atheroscler Rep. 17, 485 (2015).</li><li>Jain, M., Singh, A., Singh, V., Barthwal, M. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Involvement+of+Interleukin-1+Receptor-Associated+Kinase-1+in+Vascular+Smooth+Muscle+Cell+Proliferation+and+Neointimal+Formation+After+Rat+Carotid+Injury.">Involvement of Interleukin-1 Receptor-Associated Kinase-1 in Vascular Smooth Muscle Cell Proliferation and Neointimal Formation After Rat Carotid Injury.</a> Arterioscler Thromb Vasc Biol. , (2015).</li><li>Lee, K. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carvacrol+inhibits+atherosclerotic+neointima+formation+by+downregulating+reactive+oxygen+species+production+in+vascular+smooth+muscle+cells.">Carvacrol inhibits atherosclerotic neointima formation by downregulating reactive oxygen species production in vascular smooth muscle cells.</a> Atherosclerosis. 240, 367-373 (2015).</li><li>Li, G., Chen, S. J., Oparil, S., Chen, Y. F., Thompson, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+in+vivo+evidence+demonstrating+neointimal+migration+of+adventitial+fibroblasts+after+balloon+injury+of+rat+carotid+arteries.">Direct in vivo evidence demonstrating neointimal migration of adventitial fibroblasts after balloon injury of rat carotid arteries.</a> Circulation. 101 (12), 1362-1365 (2000).</li><li>Noda, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+endoplasmic+reticulum+stress+regulator,+gipie,+regulates+the+survival+of+vascular+smooth+muscle+cells+and+the+neointima+formation+after+vascular+injury.">New endoplasmic reticulum stress regulator, gipie, regulates the survival of vascular smooth muscle cells and the neointima formation after vascular injury.</a> Arterioscler Thromb Vasc Biol. 35 (5), 1246-1253 (2015).</li><li>Deuse, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dichloroacetate+prevents+restenosis+in+preclinical+animal+models+of+vessel+injury.">Dichloroacetate prevents restenosis in preclinical animal models of vessel injury.</a> Nature. 509 (7502), 641-644 (2014).</li><li>Guo, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=p55gamma+functional+mimetic+peptide+N24+blocks+vascular+proliferative+disorders.">p55gamma functional mimetic peptide N24 blocks vascular proliferative disorders.</a> J Mol Med (Berl). , (2015).</li><li>Oh, C. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dimethylfumarate+attenuates+restenosis+after+acute+vascular+injury+by+cell-specific+and+Nrf2-dependent+mechanisms.">Dimethylfumarate attenuates restenosis after acute vascular injury by cell-specific and Nrf2-dependent mechanisms.</a> Redox Biol. 2, 855-864 (2014).</li><li>Tae, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+N-glycoform+of+sRAGE+is+the+key+determinant+for+its+therapeutic+efficacy+to+attenuate+injury-elicited+arterial+inflammation+and+neointimal+growth.">The N-glycoform of sRAGE is the key determinant for its therapeutic efficacy to attenuate injury-elicited arterial inflammation and neointimal growth.</a> J Mol Med (Berl. 91 (12), 1369-1381 (2013).</li><li>Zhou, Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Receptor+for+AGE+(RAGE)+mediates+neointimal+formation+in+response+to+arterial+injury.">Receptor for AGE (RAGE) mediates neointimal formation in response to arterial injury.</a> Circulation. 107 (17), 2238-2243 (2003).</li><li>Lindner, V., Fingerle, J., Reidy, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+model+of+arterial+injury.">Mouse model of arterial injury.</a> Circ Res. 73 (5), 792-796 (1993).</li><li>Le, V., Johnson, C. G., Lee, J. D., Baker, A. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+model+of+femoral+artery+wire+injury+with+implantation+of+a+perivascular+drug+delivery+patch.">Murine model of femoral artery wire injury with implantation of a perivascular drug delivery patch.</a> J Vis Exp. (96), e52403 (2015).</li><li>Iannaccone, P. M., Jacob, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rats!+.">Rats! .</a> Dis Model Mech. 2 (5-6), 206-210 (2009).</li><li>Fu, Y., Sander, J. D., Reyon, D., Cascio, V. M., Joung, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improving+CRISPR-Cas+nuclease+specificity+using+truncated+guide+RNAs.">Improving CRISPR-Cas nuclease specificity using truncated guide RNAs.</a> Nat Biotechnol. 32 (3), 279-284 (2014).</li><li>Sander, J. D., Joung, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=CRISPR-Cas+systems+for+editing,+regulating+and+targeting+genomes.">CRISPR-Cas systems for editing, regulating and targeting genomes.</a> Nat Biotechnol. 32 (4), 347-355 (2014).</li><li>Tulis, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rat+carotid+artery+balloon+injury+model.">Rat carotid artery balloon injury model.</a> Methods Mol Med. 139, 1-30 (2007).</li><li>Zhang, W., Trebak, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+balloon+injury+and+intraluminal+administration+in+rat+carotid+artery.">Vascular balloon injury and intraluminal administration in rat carotid artery.</a> J Vis Exp. (94), (2014).</li><li>Tae, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vessel+ultrasound+sonographic+assessment+of+soluble+receptor+for+advanced+glycation+end+products+efficacy+in+a+rat+balloon+injury+model.">Vessel ultrasound sonographic assessment of soluble receptor for advanced glycation end products efficacy in a rat balloon injury model.</a> Curr Ther Res Clin Exp. 76, 110-115 (2014).</li><li>Tae, H. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chronic+treatment+with+a+broad-spectrum+metalloproteinase+inhibitor,+doxycycline,+prevents+the+development+of+spontaneous+aortic+lesions+in+a+mouse+model+of+vascular+Ehlers-Danlos+syndrome.">Chronic treatment with a broad-spectrum metalloproteinase inhibitor, doxycycline, prevents the development of spontaneous aortic lesions in a mouse model of vascular Ehlers-Danlos syndrome.</a> J Pharmacol Exp Ther. 343 (1), 246-251 (2012).</li><li>Sakaguchi, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Central+role+of+RAGE-dependent+neointimal+expansion+in+arterial+restenosis.">Central role of RAGE-dependent neointimal expansion in arterial restenosis.</a> J Clin Invest. 111 (7), 959-972 (2003).</li></ol>

The authors declare that they have no competing financial interests.

There have been two methods used to inflate the balloon in order to generate the injury that removes the mural endothelium in the carotid arterial lumen. One is to fill the attached syringe with liquid20, and the other is to use air pressure21. We prefer to use liquid-filled syringe because the exact liquid volume (0.02 ml) will be used for each procedure. This renders a precise and reproducible inflation of the balloon, leading to a similar level of injury in each animal undergoing the procedure. U...

Angioplasty is an endovascular procedure used to widen the narrowed or obstructed arteries resultant from pathological conditions such as atherosclerosis. One common complication of angioplasty is the post-operational neointimal hyperplasia, or restenosis, which occurs owing to surgical injuries and the subsequent inflammation-induced vascular remodeling. These conditions lead to proliferation of vascular smooth cells, and multiple pathophysiological consequences1-3. Neointimal hyperplasia re-thickens the vessel, and occurs in up to 60% post-angioplasty patients within the first year. Therefore, restenosis is a major setback of the widely used angioplasty procedure4. Although the implantation of the drug-elution stent may help to prevent restenosis, only selected candidates can undergo this costly procedure5.
Both animal and clinical studies have established that chronic inflammation generated by vascular injury and /or surgical wound serves as the main stimulus for post-angioplasty neointimal growth2,4. The rat carotid balloon injury model mimics the clinical situation and therefore serves as a valuable model system to identify cellular factors that involve in the vascular remodeling and vascular cell proliferation6-9. This model system is also a highly useful tool to evaluate and/or screen for drugs and therapeutic reagents that suppress neointimal growth in pre-clinical translational studies10-14.
Compared to the murine carotid wire injury model15 and the murine femoral artery wire injury model16, the rat carotid balloon injury model has the advantages of being sufficiently large in size for the ease of surgical procedure that facilitates reproducibility of the inflicted injury. It can provide a larger number of primary cells (e.g. vascular smooth muscle cells, endothelial cells) for additional in vitro studies to delineate the molecular mechanism governing vascular remodeling. Importantly, compared to mice, rats are also known to be a better model for physiological and toxicological studies17. Although a disadvantage or limitation of the rat model is the lack of genetic modified and gene knockout models, this disadvantage can be overcome by the availability of the rat genomic sequence and the recent development of powerful genomic editing tools such as CRISPR-CAS technology that renders possible manipulation of vast ranges of genomic sequences in different model systems18,19.
Although the rat balloon injury model has been used by multiple labs and various comprehensive protocols have been published20,21, this protocol aims at providing more details at pre-surgery preparations and may guide researchers new to this procedure to set up this surgical practice. We also emphasize the post-surgery care of the animals that allows not only post-mortem pathological and histomorphological analyses of the therapeutic effects on arterial remodeling, but also ultrasound sonographic studies in live animals13,22.

<table border="0" cellpadding="0" cellspacing="0" width="450">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">2 F Fogarty balloon embolectomy catheter&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
			<td style="width:163px;">Edwards Lifesciences&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Standard scalpel</td>
			<td style="width:163px;">Fine Science Tools</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:287px;">Small&#160; curved forceps (Large radius Dumont#7shanks curved)&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
			<td style="width:163px;">Fine Science Tools&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Large, medium and small micro-scissors</td>
			<td style="width:163px;">Roboz</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Needles (20 G)&#160;&#160;</td>
			<td style="width:163px;">TycoHealthcare</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:287px;">Micro-surgery forceps with micro-blunted atraumatic tips</td>
			<td style="width:163px;">Fine Science Tools&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Atraumatic straight small arterial clamps&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
			<td style="width:163px;">Fine Science Tools&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:287px;">Retractor&#160; with maximum spread 5.5 cm long blunt teeth</td>
			<td style="width:163px;">Fine Science Tools&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Silk suture (4.0 and&#160; 6.0 )</td>
			<td style="width:163px;">Fine Science Tools&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Syringe (1.0 ml)&#160;</td>
			<td style="width:163px;">BD&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Curity gauze sponges</td>
			<td style="width:163px;">AllegroMedical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Cotton tip applicators sterile and non-sterile</td>
			<td style="width:163px;">Puritan Medical Products</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Compact hot bead sterilizer</td>
			<td style="width:163px;">Fine Science Tools</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Self-regulating heating pad</td>
			<td style="width:163px;">Fine Science Tools&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">ADS200 anesthesia system/ventilator</td>
			<td style="width:163px;">Paragon Medical</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Isoflurane (forane), liquid form</td>
			<td style="width:163px;">Baxter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">Sodium chloride 0.9% (Saline)&#160;</td>
			<td style="width:163px;">Hospira</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:287px;">Buprenex (buprenorphine)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</td>
			<td style="width:163px;">Reckitt Benckiser Healthcare (UK) Ltd.&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">70% alcohol</td>
			<td style="width:163px;">Fisher</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:287px;">1: 10 Betadine</td>
			<td style="width:163px;">Fisher</td>
		</tr>
	</tbody>
</table>

a rat carotid balloon injury model to test anti-vascular remodeling therapeutics

The rat carotid balloon injury is a well-established surgical model that has been used to study arterial remodeling and vascular cell proliferation. It is also a valuable model system to test, and to evaluate therapeutics and drugs that negate maladaptive remodeling in the vessel. The injury, or barotrauma, in the vessel lumen caused by an inflated balloon via an inserted catheter induces subsequent neointimal growth, often leading to hyperplasia or thickening of the vessel wall that narrows, or obstructs the lumen. The method described here is sufficiently sensitive, and the results can be obtained in relatively short time (2 weeks after the surgery). The efficacy of the drug or therapeutic against the induced-remodeling can be evaluated either by the post-mortem pathological and histomorphological analysis, or by ultrasound sonography in live animals. In addition, this model system has also been used to determine the therapeutic window or the time course of the administered drug. These studies can leadto the development of a better administrative strategy and a better therapeutic outcome. The procedure described here provides a tool for translational studies that bring drug and therapeutic candidates from bench research to clinical applications.

Two weeks after the balloon injury, the rat is euthanized and the carotid arteries are isolated for histo-morphological analysis. Both operated left carotid artery and un-operated right artery are cross-sectioned, processed, and paraffin-embedded. The paraffin samples are then further thin-sectioned, and stained with hematoxylin-eosin (H &#38; E). Histo-morphological analyses are performed using a digital imaging analysis system. The details of artery harvest and histo-morphological analy...

Watch this Scientific Journal Video about A Rat Carotid Balloon Injury Model to Test Anti-vascular Remodeling Therapeutics at JoVE.com

A Rat Carotid Balloon Injury Model to Test Anti-vascular Remodeling Therapeutics

The rat carotid balloon injury model described below allows researchers to evaluate drugs or therapeutics that negate injury-induced arterial hyperplasia. Detailed pre-surgical preparation, surgical procedure, and post-surgical cares of the animal are described.

The rat carotid balloon injury is a well-established surgical model that has been used to study arterial remodeling and vascular cell proliferation. It is ...

The overall goal of this Rat Carotid Balloon Injury procedure is to mimic clinical angioplasty and its potential consequences. This message can help answer key questions in the cardiovascular research field, about the cardiovascular surgical injury elicited neointimal hyperplasia which can significantly compromise the benefits of the surgery. The main advantage of this technique is that the result can be obtained within two weeks, allowing a quick evaluation of the therapeutic reagents administered during the treatment period.Demonstrating the procedure will be Dr.Natalia Petrasheskatya from the laboratory of cardiovascular sciences and at the National Institute on Aging. Before beginning the surgery, autoclave all of the surgical instruments and use 70%ethanol to disinfect the operating platform surface. Put on the proper personal protective equipment, placing a box of sterilized gloves near the surgical platform for additional use.Next, fill a 1 milliliter syringe with sterile water and attach the syringe to a sterile, water-filled, two-way stopcock. Gently push the water through the stopcock to fill the lure-lock portion of the balloon catheter, and remove any air bubbled from the opening of the catheter. Then, test the balloon inflation to confirm that the balloon can be inflated with 0.02 milliliters of water.Now, check the pedal withdrawal reflex of an anesthetized 400 to 450 gram male Wistar rat. If the rat does not withdraw its foot, transfer the animal to the surgical platform. Cover the rat with a sterile surgical sheet, and cut the sheet to expose the neck region.Then adjust the animal into the supine position on a headed pad with the head toward the surgeon and tape the limbs into place. To isolate the left carotid artery, us a number 14 scalpel to make a straight incision from below the chin to the top of the sternum, just below the ribcage. Using a 7S forceps, blunt dissect under the skin and through the salivary gland tissues to expose the underlying muscle layer.Separate the muscle tissues to gain access to the carotid vasculature and the vagus nerve in the neck. Continue to blunt dissect the tissues surrounding the carotid artery, carefully separating the vagus nerve and the vascular fascia without damaging either tissue, until the bifurcation of the common carotid artery and the internal and external carotid branches are clearly visible. When the left common carotid artery has been exposed all the way to the sternum, place a 4-0 silk stay suture behind the artery as close to the sternum as possible.Permanently ligate the smaller arteries with the sutures, along the external carotid artery, including the ascending pharyngeal, the occipital, and the superior thyroid to avoid arterial leakage. Place another 4-0 silk stay suture immediately distal to the bifurcation, behind the external carotid artery as far from the bifurcation as possible. Then gently retract the overlying carotid artery to the right to visualize the internal carotid artery and place a 4-0 silk stay suture around the artery to avoid significant retrograde blood-loss.To introduce the balloon catheter, retract the proximal suture on the common carotid artery, and temporarily stop the blood flow with an arterial clamp. Make a small incision on the external carotid artery as distal to the suture as possible, and gently insert the uninflated balloon catheter into the incision. Advance the catheter into the lumen until it is close to the arterial clamp on the common carotid artery.Then remove the clamp and advance the catheter to the aortic arch, approximately 35 to 40 millimeters from the incision. Now use the syringe of sterile water to manually inflate the catheter to a 0.02 milliliter volume, and turn the stopcock to the locked position. Slowly withdraw the catheter while rotating to produce the injury.When the instrument is close to the arterial incision, deflate the balloon and retract the catheter back to its original position. After repeating the balloon injury procedure three times, carefully remove the catheter from the arterial lumen and close the arteriotomy with size 5-0 silk stay sutures. Release the internal carotid artery to restore the blood flow and check for arterial leakage.Finally, remove the stay sutures and clamps and close the glandular tissue with 6-0 silk sutures. Then, close the skin and monitor the animal until it is fully recovered. Two weeks after the balloon injury, the carotid arteries can be isolated for histomorphological analysis.The balloon injury elicits neointimal growth, or thickening of the vessel wall. If left untreated or treated with a saline control, compared to a non-operated vessel section from the same animal. By contrast, the vessel section from a rat that received a therapeutic reagent that blocks neointimal growth demonstrates a significantly reduced thickening in the vessel wall.The effects of the balloon injury and therapeutic treatment can also be evaluated in vivo, by ultrasound sonography. And these data collaborate well with the results from histomorphological analysis. When mastered, this techniques can be completed in 30 minutes, if it is performed properly.While attempting this procedure, it is important to remember to prepare and test the balloon catheter for leaks prior to the surgery. After watching this video, you should have a good understanding of how to perform the rat carotid balloon injury procedure, for evaluating tracks and therapeutic reagents that block neointimal growth and to study the mag-ni-sen of injury elicited neointimal growth. Don't forget that working with animals requires an approved protocol by your institutional AICUC.You should also consult with your institutional laboratory animal veterinarians to establish the best practices for post-surgical care, and monitoring of the animals.

a-rat-carotid-balloon-injury-model-to-test-anti-vascular-remodeling

Research

JoVE Journal

Medicine

8.6K visualizações.  National Institute on Aging. The overall goal of this Rat Carotid Balloon Injury procedure is to mimic clinical angioplasty and its potential consequences. This message can help answer key questions in the cardiovascular research field, about the cardiovascular surgical injury elicited neointimal hyperplasia which can significantly compromise the benefits of the surgery. The main advantage of this technique is that the result can be obtained within two weeks, allowing a quick evaluation of the therapeutic reagents admini...