This work was supported in part by the National Institutes of Health Grants R56-HL095498,&#160;R01-HL-095498 (to AD),&#160;R01-HL128406, the Merit Review Award I01-BX002336 from the United States Department of Veterans Affairs Biomedical Laboratory Research and Development Program (to AD), a Yale Department of Surgery Ohse award (to AD), a Sarnoff Cardiovascular Foundation Fellowship (to JMS), and through the resources and the use of facilities at the Veterans Affairs Connecticut Healthcare System (West Haven, CT). Bovine pericardial patches were generously provided by LeMaitre Vascular Inc. (Burlington, MA).

Approval by the appropriate Institutional Animal Care and Use Committee must be obtained, indicating that your protocol follows the guidelines of your institution&#39;s animal research ethics committee.
1. Anesthesia and Pre-operative Procedures
<ol>
	<li>Anesthetize male Wistar rats, weighing around 200 g, with vaporized 3% isoflurane and 1 L/min oxygen administered into an acrylic induction chamber.</li>
	<li>Confirm adequate anesthesia through a lack of reaction to a toe and tail pinch. P...

<ol>
	<li>Muto, A., Nishibe, T., Dardik, H., Dardik, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Patches+for+carotid+artery+endarterectomy:+current+materials+and+prospects.">Patches for carotid artery endarterectomy: current materials and prospects.</a> J Vasc Surg. 50 (1), 206-213 (2009).</li><li>Li, X., 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=Current+usage+and+future+directions+for+the+bovine+pericardial+patch.">Current usage and future directions for the bovine pericardial patch.</a> Ann Vasc Surg. 25 (4), 561-568 (2011).</li><li>Biasi, G. M., Sternjakob, S., Mingazzini, P. M., Ferrari, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nine-year+experience+of+bovine+pericardium+patch+angioplasty+during+carotid+endarterectomy.">Nine-year experience of bovine pericardium patch angioplasty during carotid endarterectomy.</a> J Vasc Surg. 36 (2), 271-277 (2002).</li><li>Papakostas, J. C., 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=Use+of+the+vascu-guard+bovine+pericardium+patch+for+arteriotomy+closure+in+carotid+endarterectomy.+Early+and+long-term+results.">Use of the vascu-guard bovine pericardium patch for arteriotomy closure in carotid endarterectomy. Early and long-term results.</a> Ann Vasc Surg. 28 (5), 1213-1218 (2014).</li><li>Ohwada, S., 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=Glutaraldehyde-fixed+heterologous+pericardium+for+vena+cava+grafting+following+hepatectomy.">Glutaraldehyde-fixed heterologous pericardium for vena cava grafting following hepatectomy.</a> Hepatogastroenterology. 46 (26), 855-858 (1999).</li><li>Mori, A., 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=Standard+hepatic+vein+reconstruction+with+patch+plasty+using+the+native+portal+vein+in+adult+living+donor+liver+transplantation.">Standard hepatic vein reconstruction with patch plasty using the native portal vein in adult living donor liver transplantation.</a> Liver Transpl. 18 (5), 602-607 (2012).</li><li>Bai, H., 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=Pericardial+patch+venoplasty+heals+via+attraction+of+venous+progenitor+cells.">Pericardial patch venoplasty heals via attraction of venous progenitor cells.</a> Physiological Reports. 4 (12), (2016).</li><li>Li, X., 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=Pericardial+patch+angioplasty+heals+via+an+Ephrin-B2+and+CD34+positive+cell+mediated+mechanism.">Pericardial patch angioplasty heals via an Ephrin-B2 and CD34 positive cell mediated mechanism.</a> PLoS One. 7 (6), 38844 (2012).</li><li>Bai, H., 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=Pretreatment+of+pericardial+patches+with+antibiotics+does+not+alter+patch+healing+in+vivo.">Pretreatment of pericardial patches with antibiotics does not alter patch healing in vivo.</a> J Vasc Surg. 63 (4), 1063-1073 (2016).</li><li>Muto, A., 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=Eph-B4+prevents+venous+adaptive+remodeling+in+the+adult+arterial+environment.">Eph-B4 prevents venous adaptive remodeling in the adult arterial environment.</a> J Exp Med. 208 (3), 561-575 (2011).</li></ol>

We describe a patch angioplasty model in the rat that can be used in either veins or arteries, creating a patch venoplasty or patch arterioplasty, respectively. Using this pericardial patch model, we showed aggressive and stable neointimal hyperplasia in the rat IVC venoplasty compared to the aortic arterioplasty (Figure 2)7,8.
Several technical aspects are notable. In the aortic arterioplasty, it is important that the...

Vascular surgeons commonly close blood vessels with pericardial patches, either bovine or porcine, to reduce the risk of restenosis1,2. In arterial surgery, pericardial patch angioplasty reduces the rate of restenosis compared to a primary closure3,4. Patch venoplasty is also similarly performed to close veins, although less frequently when compared to arterial procedures5,6. Patches typically develop neointimal hyperplasia on their luminal surfaces; however, the mechanism of neointimal formation remains unclear, especially in the comparison of differences in neointimal formation between the arterial and venous environments. We previously showed that pericardial patches attract progenitor cells in both the arterial and the venous environments and that venous patch angioplasty shows more aggressive neointimal formation as compared to the arterial patches7,8.
In this study, we describe the rat model of pericardial patch angioplasty that is common to closing both veins and arteries and that may be used to study neointimal formation; this method is a small-animal model of an operative technique commonly used in human patients. The rat model has a larger diameter than the mouse model, facilitating technical aspects of the surgery and improving the learning curve for the model.

<table border="0" cellpadding="0" cellspacing="0" width="523">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Bovine pericardial patch</td>
			<td colspan="2" style="width:307px;">LeMaitre Vascular</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Vascular clamp</td>
			<td>Roboz Surgical Instrument Co.</td>
			<td>RS-5424</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Clamp applying forceps</td>
			<td>Roboz Surgical Instrument Co</td>
			<td>RS-5410</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10-0 Prolene suture</td>
			<td>Arosurgical Co.</td>
			<td>T05A10N10-13</td>
		</tr>
	</tbody>
</table>

patch angioplasty in the rat aorta or inferior vena cava

Pericardial patches are commonly used in vascular surgery to close vessels. To facilitate studies of the neointimal hyperplasia that forms on the patch, we developed a rat model of patch angioplasty that can be used in either a vein or an artery, creating a patch venoplasty or a patch arterioplasty, respectively. Technical aspects of this model are discussed. The infra-renal IVC or aorta are dissected and then clamped proximally and distally. A 3 mm venotomy or arteriotomy is performed in the infrarenal inferior vena cava or aorta of 6 to 8 week-old Wistar rats. A bovine pericardial patch (3 mm x 1.5 mm x 0.6 mm) is then used to close the site using a 10-0 nylon suture. Compared to arterial patches, venous patches show increased neointimal thickness on postoperative day 7. This novel model of pericardial patch angioplasty can be used to examine neointimal hyperplasia on vascular biomaterials, as well as to compare the differences between the arterial and venous environments.

After the patch angioplasty, there was no thrombosis in either the venous (n = 42) or arterial (n = 24) patch groups. Survival at day 7 was 100% in both groups with either a venous or arterial patch.
The patches were harvested on day 7 and stained with hematoxylin and eosin, and the neointimal thickness was compared as previously described7. Because of the distinct morphological difference between the patch and the ne...

Watch this Scientific Journal Video about Patch Angioplasty in the Rat Aorta or Inferior Vena Cava at JoVE.com

Patch Angioplasty in the Rat Aorta or Inferior Vena Cava

We have established a model of pericardial patch angioplasty that can be used in either small-diameter veins or arteries. This model can be used to compare venous and arterial neointimal hyperplasia formation.

Pericardial patches are commonly used in vascular surgery to close vessels. To facilitate studies of the neointimal hyperplasia that forms on the patch, ...

The overall goal of this procedure is to install vascular biomaterials into either the arterial or venous environment. This method can help answer key questions in the difference of neointimal hyperplasia that forms on biomaterials placed in the arterial or venous environments. The main advantage of this technique is that it's easy to learn, and need only a short time to perform.After confirming a lack of response to toe pinch, administer buprenorphine via IP as a preemptive analgesia. Remove the hair on the animal's ventral abdomen. Next, use micro scissors to trim a bovine pericardial patch to a 3 x 1.5 x 0.6 millimeter size, and soak the patch in 10 milliliters of sterilized saline in a cell culture dish for five minutes.While the patch is soaking, disinfect the incision site with a topical antiseptic, and cover the animal with a surgical drape. Under a dissecting microscope, use a scalpel to make a midline abdominal incision extending from the xiphoid process to just above the pubis, and insert a retractor into the incision. When the abdominal cavity has been opened, extract the bowel from the abdominal cavity to the right side of the animal, and wrap the tissue in saline-soaked gauze.Using sterile cotton swabs, expose the infrarenal vena cava, or IVC. Then use forceps to dissect the IVC free at approximately two millimeters below the origin of the renal veins, and use 6-0 nylon sutures to ligate and divide all of the lumbar and tributary veins. Next, place two microsurgery clips across both the proximal and distal infrarenal IVCs, and use a 25 gauge needle to puncture the anterior wall of the IVC, using scissors to enlarge the puncture to around three millimeters.Now completely close the venotomy with the patch and 10-0 nylon sutures. Remove the distal clamp to vent the patch, followed by removal of the proximal clamp to restore the blood flow to the IVC. Then observe the patch for 30 seconds without compression to confirm hemostasis, and return the bowels to the abdominal cavity, closing the abdomen with a running suture according to approved animal protocols.Apply postoperative care, including analgesia and wound care in accordance with the recommendations of the institutional animal care and use committee, monitoring the animal until full sternal recumbency is achieved. For a patch arterioplasty, soak the trimmed patch in sterile saline as just demonstrated. After extracting the bowels as for the venoplasty, use sterile cotton swabs to expose the aorta.Then free the aorta approximately two millimeters below the origin of the renal arteries, and use 6-0 nylon sutures to ligate and divide all of the lumbar arteries. Next, clamp the infrarenal aorta, and use a 25 gauge needle to puncture the anterior wall of the aorta. Use scissors to enlarge the puncture to around three millimeters.Then completely close the arteriotomy with the patch and running 10-0 nylon sutures. Remove the distal clamp first to vent the patch, followed by removal of the proximal clamp to restore the blood flow to the aorta. After confirmation of hemostasis, return the bowels to the abdominal cavity, and close the abdomen with a running suture according to the approved animal protocols, providing postoperative care as just demonstrated.On day seven harvested IVC patches, there is a distinct layer of thick neointima on the lumenal side of the patch with more cells accumulated in the neointima. In the arterial patch, there is typically a much thinner neointimal layer, with only a few cells attached to the lumenal side of the patch. Indeed, quantitative comparison of the neointima thickness between the two patch environments indicates that the neointima is significantly thicker in the venous patch environment compared to the artery patch, suggesting that the patch venoplasty model is superior to the other models for acquiring a thick neointima in a short period of time.Once mastered, this technique can be done in 30 to 40 minutes if it's performed proper. After its development, this technique paved the way for researchers in the field of vascular biology to explore neointimal hyperplasia in vascular disease.

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10.4K visualizações.  Yale University. The overall goal of this procedure is to install vascular biomaterials into either the arterial or venous environment. This method can help answer key questions in the difference of neointimal hyperplasia that forms on biomaterials placed in the arterial or venous environments. The main advantage of this technique is that it's easy to learn, and need only a short time to perform.After confirming a lack of response to toe pinch, administer buprenorphine via IP as a preemptive analgesia....