This study is supported by the American Venous Forum (AVF) 2023 Basic Science research grant and Surmodics, Inc.

The following protocol follows the University of Michigan (UMICH) Institutional Animal Care and Use Committee (IACUC) policies and guidelines, the U.S. Government Principles for the Utilization and Care of Vertebrate Animals Used in Testing, Research, and Training, and the ARRIVE guidelines 2.0. The UMICH Animal Welfare Assurance agreement is compliant with OLAW and USDA and is fully accredited by AAALAC International. This protocol was approved with the ID number PRO00010841. Male outbred Sprague Dawley rats from Charle...

Rodent Venoplasty Balloon Model for Deep Vein Treatment Studies

<ol>
	<li>Prandoni, 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=The+long-term+clinical+course+of+acute+deep+venous+thrombosis.">The long-term clinical course of acute deep venous thrombosis.</a> Ann Inter Med. 125 (1), 1-7 (1996).</li><li>Prandoni, P., Kahn, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Post-thrombotic+syndrome:+prevalence,+prognostication+and+need+for+progress.">Post-thrombotic syndrome: prevalence, prognostication and need for progress.</a> Br J Haematol. 145 (3), 286-295 (2009).</li><li>Gloviczki, 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=The+2023+Society+for+Vascular+Surgery,+American+Venous+Forum,+and+American+Vein+and+Lymphatic+Society+clinical+practice+guidelines+for+the+management+of+varicose+veins+of+the+lower+extremities.+Part+II.">The 2023 Society for Vascular Surgery, American Venous Forum, and American Vein and Lymphatic Society clinical practice guidelines for the management of varicose veins of the lower extremities. Part II.</a> J Vas Surg Venous Lymph Diso. 12 (1), 101670 (2024).</li><li>Henke, P., Sharma, S., Wakefield, T., Myers, D., Obi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+from+experimental+post-thrombotic+syndrome+and+potential+for+novel+therapies.">Insights from experimental post-thrombotic syndrome and potential for novel therapies.</a> Transl Res. 225, 95-104 (2020).</li><li>Diaz, J. 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=Choosing+a+mouse+model+of+venous+thrombosis:+A+consensus+assessment+of+utility+and+application.">Choosing a mouse model of venous thrombosis: A consensus assessment of utility and application.</a> Arterioscl Thrombo Vasc Biol. 39 (3), 311-318 (2019).</li><li>Lee, Y. U., Lee, A. Y., Humphrey, J. D., Rausch, 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=Histological+and+biomechanical+changes+in+a+mouse+model+of+venous+thrombus+remodeling.">Histological and biomechanical changes in a mouse model of venous thrombus remodeling.</a> Biorheology. 52 (3), 235-245 (2015).</li><li>Xie, 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=Correspondence+of+ultrasound+elasticity+imaging+to+direct+mechanical+measurement+in+aging+DVT+in+rats.">Correspondence of ultrasound elasticity imaging to direct mechanical measurement in aging DVT in rats.</a> Ultrasound Med Biol. 31 (10), 1351-1359 (2005).</li><li>Moini, M., 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=Venoplasty+and+stenting+in+post-thrombotic+syndrome+and+non-thrombotic+iliac+vein+lesion.">Venoplasty and stenting in post-thrombotic syndrome and non-thrombotic iliac vein lesion.</a> Minim Invasive Ther Allied Technol. 29 (1), 35-41 (2020).</li><li>Chaitidis, N., 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=Management+of+post-thrombotic+syndrome:+A+comprehensive+review.">Management of post-thrombotic syndrome: A comprehensive review.</a> Curr Pharma Des. 28 (7), 550-559 (2022).</li><li>Dangas, G. D., 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=In-stent+restenosis+in+the+drug-eluting+stent+era.">In-stent restenosis in the drug-eluting stent era.</a> J Am Coll Cardiol. 56 (23), 1897-1907 (2010).</li><li>Negl&#233;n, P., Berry, M. A., Raju, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endovascular+surgery+in+the+treatment+of+chronic+primary+and+post-thrombotic+iliac+vein+obstruction.">Endovascular surgery in the treatment of chronic primary and post-thrombotic iliac vein obstruction.</a> Euro J Vas Endovas Surg. 20 (6), 560-571 (2000).</li><li>Sharifi, M., Mehdipour, M., Bay, C., Smith, G., Sharifi, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endovenous+therapy+for+deep+venous+thrombosis:+The+TORPEDO+trial.">Endovenous therapy for deep venous thrombosis: The TORPEDO trial.</a> Catheter Cardiovasc Interv. 76 (3), 316-325 (2010).</li><li>Nicklas, J. M., Gordon, A. E., Henke, P. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Resolution+of+deep+venous+thrombosis:+Proposed+immune+paradigms.">Resolution of deep venous thrombosis: Proposed immune paradigms.</a> Int J Mol Sci. 21 (6), 2080 (2020).</li><li>Li, J., Kim, S. G., Blenis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapamycin:+One+drug,+many+effects.">Rapamycin: One drug, many effects.</a> Cell Metabol. 19 (3), 373-379 (2014).</li><li>Chen, 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=Rapamycin+regulates+Akt+and+ERK+phosphorylation+through+mTORC1+and+mTORC2+signaling+pathways.">Rapamycin regulates Akt and ERK phosphorylation through mTORC1 and mTORC2 signaling pathways.</a> Mol Carcinogen. 49 (6), 603-610 (2010).</li><li>Diaz, J. A., Farris, D. M., Wrobleski, S. K., Myers, D. D., Wakefield, T. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inferior+vena+cava+branch+variations+in+C57BL/6+mice+have+an+impact+on+thrombus+size+in+an+IVC+ligation+(stasis)+model.">Inferior vena cava branch variations in C57BL/6 mice have an impact on thrombus size in an IVC ligation (stasis) model.</a> J Thromb Haemo. 13 (4), 660-664 (2015).</li><li>Sch&#246;nfelder, T., J&#228;ckel, S., Wenzel, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+models+of+deep+vein+thrombosis.">Mouse models of deep vein thrombosis.</a> Gef&#228;sschirurgie. 22 (1), 28-33 (2017).</li><li>de Barros, R. S. M., 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=Morphometric+analysis+of+rat+femoral+vessels+under+a+video+magnification+system.">Morphometric analysis of rat femoral vessels under a video magnification system.</a> J Vasc Bras. 16 (1), 73-76 (2017).</li></ol>

The VBM can be performed on rats &#8805; 250 g using balloons in the 2.5-3.5 mm range. For rats exceeding 750 g, the technique is limited by a higher amount of adipose tissue in the abdominal cavity and organ size rather than changes in IVC diameter. From our experience, we have found that 10 or more animals per group are needed to obtain statistical significance between the groups for vein wall protein analysis or activity assays and histology. Periodic temperature control and respiration rate surveillance during surgic...

Deep vein obstructions from unresolved thrombi are a common consequence of deep vein thrombosis (DVT) and are one of the causes of post-thrombotic syndrome (PTS), costing billions of dollars in healthcare and significantly impacting the quality of life1,2,3. PTS is a unique inflammatory pathology with consequent vein wall fibrosis4 not fully captured in small animal DVT models5,6,7, and more importantly, previous models cannot evaluate the response to therapeutic interventions. Thrombotic venous obstructions are often treated by stenting and balloon venoplasty8,9; such interventions are hampered by a high reintervention rate due to restenosis and occlusion10,11,12.
Despite the availability of drug-coated balloons to address arterial-specific stenosis/occlusions, none exist for deep veins. The molecular mechanism behind restenosis is poorly understood in veins and has no direct therapy4. Therefore, our goal is to present an animal model that can test locally delivered therapeutics via venoplasty balloons simulating deep vein post-thrombotic obstructions. This model reproduces the post-thrombotic condition and evaluates how different types of venoplasty balloons affect the vein wall in vivo.

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			<td>Heifetz Microclips 8mmx1.75mm&#160;</td>
			<td>SCANLAN</td>
			<td>3795-14</td>
			<td>Straight</td>
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			<td>Heifetz Microclips 8mmx1.75mm&#160;</td>
			<td>SCANLAN</td>
			<td>3795-18</td>
			<td>Curved</td>
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			<td>Inflation device&#160;</td>
			<td>Merit Medical</td>
			<td>IN4130</td>
			<td>BasixCOMPAK with Analog Display</td>
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			<td>Isoflurane</td>
			<td>MFR VETONE</td>
			<td>SKU-501017</td>
			<td>100mL, Liquid for Inhalation</td>
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			<td>Microsurgery kit containing tweezers and forceps</td>
			<td>Customized</td>
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			<td>Oxygen, E-tank</td>
			<td>Medline</td>
			<td>MDM1630</td>
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			<td>Sharpened Guidewire</td>
			<td>Customized</td>
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			<td>Sterile Glad Press-n-Seal</td>
			<td>Glad</td>
			<td>SKU # PSS-140</td>
			<td>ETO Exposed</td>
		</tr>
		<tr>
			<td>Sterile Nonwoven Gauze Sponges 2s 4ply 4x4&#160;</td>
			<td>Medline</td>
			<td>SKU PRM21444H</td>
			<td>100Ct</td>
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			<td>Surgical microscope&#160;</td>
			<td>Zeiss</td>
			<td>S100 / OPMI pico</td>
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			<td>Surgical Scrub &#38; Handwash</td>
			<td>Vetoquinol</td>
			<td>NDC: 17030-003-16</td>
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			<td>Ultrasound Gel</td>
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			<td>ACUSON Antares</td>
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			<td>Venoplasty Balloon</td>
			<td>Customized</td>
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rodent inferior vena cava venoplasty balloon model

Balloon venoplasty is a commonly used clinical technique to treat deep vein stenosis and occlusion as a consequence of trauma, congenital anatomic abnormalities, acute deep vein thrombosis (DVT), or stenting. Chronic deep venous obstruction is histopathologically characterized by thrombosis, fibrosis, or both. Currently, no direct treatment is available to target these pathological processes. Therefore, a reliable in vivo animal model to test novel interventions is necessary. The rodent survival inferior vena cava (IVC) venoplasty balloon model (VBM) allows the study of balloon venoplasty in non-thrombotic and post-thrombotic conditions across multiple time points. The local and systemic effect of coated and uncoated venoplasty balloons can be quantified via tissue, thrombus, and blood assays such as real-time polymerase chain reaction (RT-PCR), western blot, enzyme-linked immunosorbent assay (ELISA), zymography, vein wall and thrombus cellular analysis, whole blood and plasma assays, and histological analysis. The VBM is reproducible, replicates surgical human interventions, can identify local vein wall-thrombi protein changes, and allows multiple analyses from the same sample, decreasing the number of animals required per group.

Author Spotlight: Utilizing Venoplasty Balloon Model in Rodents to Simulate Surgical Interventions for Deep Veins

Rodent Inferior Vena Cava Venoplasty Balloon Model

In our laboratory, led by Dr.Andrea Obi, we study a type of abnormal blood clotting, venous thrombosis. In fact, we're one of the very few laboratories in the world working in this promising discovery area. Our goal is to take our findings and translate them into new, safer, more effective approaches to treat venous thrombosis.Our work has led us to look more closely at the role of the immune system, including the presence of infection in thrombus formation, as well as the pathways leading to clot resolution, venous fibrosis, including vein wall scarring and post-thrombotic syndrome. No previous animal model has been able to replicate the complex immune interactions that occur in venous thromboembolism in humans. Additionally, no model has been able to characterize the response to endovascular treatments followed by ultrasound.We are making important contributions to understand how different types of immune cells interact with environment around a blood clot, and how those interactions can lead to changes in the expression of cell's genetics code, a process now as epigenetic regulation. We believe that Inferior Vena Cava Venoplasty Balloon Model will accelerate the development of novel balloon angioplasty prototypes for the treatment of venous thrombosis, and the possibility for prevention of post-thrombotic syndrome.

The VBM is a model that evaluates the effect of venoplasty balloons in complete hemostasis control. First, we quantified the IVC (mid-infrarenal section) diameter, as shown in Figure 1, for correct balloon sizing. Second, the developed step-by-step microsurgical technique is illustrated in Figure 2, and we also show examples of the critical steps in Figure 3. Notice the retrograde approach used for the IVC canulation with the sharpe...

The protocol presents a survival rodent model to test venoplasty balloon (VB) interventions in non-thrombotic, thrombotic, and post-thrombotic deep veins.

Balloon venoplasty is a commonly used clinical technique to treat deep vein stenosis and occlusion as a consequence of trauma, congenital anatomic ...

rodent-inferior-vena-cava-venoplasty-balloon-model