Name: ischemic tissue injury in the dorsal skinfold chamber of the mouse: a skin flap model to investigate acute persistent ischemia
Uploaded: 2014-11-17T14:00:00
Description: Watch this Scientific Journal Video about Ischemic Tissue Injury in the Dorsal Skinfold Chamber of the Mouse: A Skin Flap Model to Investigate Acute Persistent Ischemia at JoVE.com

We thank Katharina Haberland for image editing. &#160;Funding: The senior author received a KKF Grant from the Technische Universit&#228;t M&#252;nchen to set up a new research laboratory.

NOTE: Prior to implementation of the presented model, the corresponding animal protection laws must be consulted and permission must be obtained from the local authorities. In this work, all experiments were performed in conformity with the guiding principles for research involving animals and the German legislation on protection of animals. The experiments were approved by the local animal care committee.
1. Animal Preparation and Surgical Elevation of the Flap
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<ol>
	<li>McFarlane, R., De Young, G., Henry, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+design+of+a+pedicle+flap+in+the+rat+to+study+necrosis+and+its+prevention.">The design of a pedicle flap in the rat to study necrosis and its prevention.</a> Plast Reconstr Surg. 35, 177-182 (1965).</li><li>Finseth, F., Cutting, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+experimental+neurovascular+island+skin+flap+for+the+study+of+the+delay+phenomenon.">An experimental neurovascular island skin flap for the study of the delay phenomenon.</a> Plast Reconstr Surg. 61, 412-420 (1978).</li><li>Petry, J. J., Wortham, K. 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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+microvascular+oxygen+supply+and+tissue+oxygenation+in+hepatic+ischemia/reperfusion.">Assessment of microvascular oxygen supply and tissue oxygenation in hepatic ischemia/reperfusion.</a> Adv. Exp. Med. Biol. 428, 403-408 (1997).</li><li>Menger, M. D., Barker, J. H., Messmer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capillary+blood+perfusion+during+postischemic+reperfusion+in+striated+muscle.">Capillary blood perfusion during postischemic reperfusion in striated muscle.</a> Plast Reconstr Surg. 89, 1104-1114 (1992).</li><li>Uhl, E., R&#246;sken, F., Curri, S. B., Menger, M. D., Messmer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduction+of+skin+flap+necrosis+by+transdermal+application+of+buflomedil+bound+to+liposomes.">Reduction of skin flap necrosis by transdermal application of buflomedil bound to liposomes.</a> Plast Reconstr Surg. 102, 1598-1604 (1998).</li><li>Pang, C. Y., Neligan, P., Nakatsuka, T., Sasaki, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+the+fluorescein+dye+test+for+prediction+of+skin+flap+viability+in+pigs.">Assessment of the fluorescein dye test for prediction of skin flap viability in pigs.</a> J Surg Res. 41, 173-181 (1986).</li><li>Hjortdal, V. E., Hansen, E. S., Henriksen, T. B., Kjolseth, D., Soballe, K., Djurhuus, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+microcirculation+of+myocutaneous+island+flaps+in+pigs+studied+with+radioactive+blood+volume+tracers+and+microspheres+of+different+sizes.">The microcirculation of myocutaneous island flaps in pigs studied with radioactive blood volume tracers and microspheres of different sizes.</a> Plast Reconstr Surg. 89, 116-122 (1992).</li><li>Pang, C. Y., Neligan, P., Nakatsuka, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+microsphere+technique+for+measurement+of+capillary+blood+flow+in+random+skin+flaps+in+pigs.">Assessment of microsphere technique for measurement of capillary blood flow in random skin flaps in pigs.</a> Plast Reconstr Surg. 74, 513-521 (1984).</li><li>Sandison, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+method+for+the+microscopic+study+of+living+growing+tissues+by+the+introduction+of+a+transparent+chamber+in+the+rabbit's+ear.">A new method for the microscopic study of living growing tissues by the introduction of a transparent chamber in the rabbit's ear.</a> The Anatomical Record. 28, 281-287 (1924).</li><li>Algire, G. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Adaptation+of+the+Transparent-Chamber+Technique+to+the+Mouse.">An Adaptation of the Transparent-Chamber Technique to the Mouse.</a> Journal of the National Cancer Institute. 4, 1-11 (1943).</li><li>Lehr, H. A., Leunig, M., Menger, M. D., Nolte, D., Messmer, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dorsal+skinfold+chamber+technique+for+intravital+microscopy+in+nude+mice.">Dorsal skinfold chamber technique for intravital microscopy in nude mice.</a> Am J Pathol. 4, 1055-1062 (1993).</li><li>Barker, J. 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=An+animal+model+to+study+microcirculatory+changes+associated+with+vascular+delay.">An animal model to study microcirculatory changes associated with vascular delay.</a> Br J Plast Surg. 52, 133-142 (1999).</li><li>Erni, D., Sakai, H., Banic, A., Tschopp, H. M., Intaglietta, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+assessment+of+microhemodynamics+in+ischemic+skin+flap+tissue+by+intravital+microscopy.">Quantitative assessment of microhemodynamics in ischemic skin flap tissue by intravital microscopy.</a> Ann Plast Surg. 43, 405-414 (1999).</li><li>Roesken, F., Sch&#228;fer, T., Spitzer, W. J., Vollmar, B., Menger, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+analysis+of+the+microcirculation+of+osteomyocutaneous+flaps+using+fluorescence+microscopy.">In vivo analysis of the microcirculation of osteomyocutaneous flaps using fluorescence microscopy.</a> Br J Plast Surg. 52, 644-652 (1999).</li><li>Harder, Y., Amon, M., Erni, D., Menger, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+ischemic+tissue+injury+in+a+random+pattern+flap:+a+new+mouse+model+using+intravital+microscopy.">Evolution of ischemic tissue injury in a random pattern flap: a new mouse model using intravital microscopy.</a> J Surg Res. 121, 197-205 (2004).</li><li>Harder, Y., Contaldo, C., Klenk, J., Banic, A., Jakob, S. M., Erni, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preconditioning+with+monophosphoryl+lipid+A+improves+survival+of+critically+ischemic+tissue.">Preconditioning with monophosphoryl lipid A improves survival of critically ischemic tissue.</a> Anesth Analg. 100, 1786-1792 (2005).</li><li>Rezaeian, F., 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=Erythropoieton+protects+critically+perfused+flap+tissue.">Erythropoieton protects critically perfused flap tissue.</a> Ann Surg. 248, 919-929 (2008).</li><li>Harder, Y., 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=Erythropoietin+reduces+necrosis+in+critically+ischemic+myocutaneous+tissue+by+protecting+nutritive+perfusion+in+a+dose-dependent+manner.">Erythropoietin reduces necrosis in critically ischemic myocutaneous tissue by protecting nutritive perfusion in a dose-dependent manner.</a> Surgery. 145, 10-1016 (2009).</li><li>Rezaeian, F., 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=Erythropoietin-induced+upregulation+of+endothelial+nitric+oxide+synthase+but+not+vascular+endothelial+growth+factor+prevents+musculocutaneous+tissue+from+ischemic+damage.">Erythropoietin-induced upregulation of endothelial nitric oxide synthase but not vascular endothelial growth factor prevents musculocutaneous tissue from ischemic damage.</a> Lab Invest. 90, 40-51 (2010).</li><li>Rezaeian, F., Ong, M. 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D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=N-acetylcysteine+attenuates+leukocytic+inflammation+and+microvascular+perfusion+failure+in+critically+ischemic+random+pattern+flaps.">N-acetylcysteine attenuates leukocytic inflammation and microvascular perfusion failure in critically ischemic random pattern flaps.</a> Microvasc Res. 82, 28-34 (2011).</li><li>Rezaeian, F., 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=Ghrelin+protects+musculocutaneous+tissue+from+ischemic+necrosis+by+improving+microvascular+perfusion.">Ghrelin protects musculocutaneous tissue from ischemic necrosis by improving microvascular perfusion.</a> Am J Physiol Heart Circ Physiol. 302, 603-610 (2012).</li><li>Rezaeian, F., 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=Long-term+preconditioning+with+Erythropoietin+reduces+ischemia-induced+skin+necrosis.">Long-term preconditioning with Erythropoietin reduces ischemia-induced skin necrosis.</a> Microcirculation. , (2013).</li><li>Harder, Y., 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=Heat+shock+preconditioning+reduces+ischemic+tissue+necrosis+by+heat+shock+protein+(HSP)-32-mediated+improvement+of+the+microcirculation+rather+than+induction+of+ischemic+tolerance.">Heat shock preconditioning reduces ischemic tissue necrosis by heat shock protein (HSP)-32-mediated improvement of the microcirculation rather than induction of ischemic tolerance.</a> Ann Surg. 242, 869-878 (2005).</li><li>Tobalem, 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=Local+shockwave-induced+capillary+recruitment+improves+survival+of+musculocutaneous+flaps.">Local shockwave-induced capillary recruitment improves survival of musculocutaneous flaps.</a> J Surg Res. 184, 1196-1204 (2013).</li><li>Lindenblatt, N., Calcagni, M., Contaldo, C., Menger, M. 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In order to decrease ischemic complications and thereby improve the clinical outcome, more detailed knowledge of pathophysiologic processes in critically perfused flap tissue is required. The development of new animal models that mimic acute persistent ischemia is therefore mandatory. Accordingly, we were able to develop an easily reproducible and reliable model allowing for repetitive morphological, dynamic and functional real-time evaluation of various parameters of muscle and skin vasculature that can be correlated wi...

Coverage of exposed tendon, bone and implant material in reconstructive surgery relies on the use of flaps. A flap is a block of tissue that is transferred on its vascular pedicle that guarantees arterial inflow and venous outflow. Despite broad expertise and the availability of a variety of flaps to be transferred, ischemia-induced complications ranging from wound breakdown to total tissue loss are still encountered. Whereas conservative treatment and healing by secondary intention can be expected after minor tissue necrosis, significant flap necrosis usually requires surgical revision, including debridement, wound conditioning and secondary reconstruction. This increases morbidity, prolongs hospital stay and consequently leads to increased health care costs.
Flaps with an undefined pattern of vasculature or randomly perfused areas in the distal zone most remote from the arterial inflow are particularly prone to ischemic damage. Accordingly, numerous experimental and clinical studies have evaluated the development of necrosis in both, axial pattern flaps (defined blood supply) and random pattern flaps (undefined blood supply)1-3. The main findings are commonly based on macroscopic evaluation of the size of the necrotic area. In order to assess the causes and mechanisms of tissue necrosis more in detail, several studies focused on the analysis of microcirculation. Different techniques have been used to measure tissue perfusion, including the analysis of tissue oxygen tension using polarographic electrodes4-5, as well as the measurement of blood flow using laser Doppler flowmetry6-7, dye diffusion8, and microspheres9-10. These techniques, however, only allow for measuring indirect parameters of tissue perfusion and do not enable any morphological analysis of the microhemodynamic processes within an individual area of interest of a flap.
Sandison is known to be the first who has used a transparent chamber for prolonged in vivo studies, which he performed in rabbits11. In 1943 &#8212; approximately 20 years later &#8212; Algire was the first to adapt such a transparent chamber to be applicable in mice in order to study the behavior of micro-implants of tumor cells12. Due to the fact that mice are so-called loose skin animals and after some technical refinements over the following years, Lehr and co-workers were able to adapt such a dorsal skinfold chamber developing a smaller and lighter titanium chamber. This chamber enabled evaluation using intravital fluorescence microscopy, a technique that allows direct and repetitive visualization of a number of morphologic and microcirculatory features and their changes over time under different physiological and pathophysiological conditions, such as ischemia-reperfusion injury13.
In the investigation of perfusion of skin, muscle and bone flaps under normal and pathological conditions two trends occurred: First, the &#8220;acute&#8221; flap models that do not use the dorsal skinfold chamber such as the pedicled ear flap in the mouse14, the laterally based island skin flap in the hamster15 and the pedicled composite flap in the rat16. Second, the &#8220;chronic&#8221; flap model where the combination of a flap with a dorsal skinfold chamber permits repetitive microcirculatory analyses over several days with intravital fluorescence microscopy. It consists of a randomly perfused musculocutaneous flap that is integrated in the skinfold chamber of the mouse 17. Its width-to-length ratio was chosen that a situation of acute persistent ischemia consistently results in ~50% flap tissue necrosis 10 to 14 days after flap elevation. This reproducible extent of tissue necrosis allows further evaluation of both, protective (i.e., development of less necrosis) and detrimental factors (i.e., development of more necrosis) on flap pathophysiology. During the last years, several experimental publications demonstrating the effect of different pre-, peri- and post-conditioning procedures, including the administration of tissue-protective substances18-24 and the local application of physiologic stressors such as heat25 and shockwaves26, have emerged.
The quantitative analyses of necrosis, microvascular morphology and microcirculatory parameters can further be correlated to immunohistochemical analyses and protein assays. Different proteins and molecules including vascular endothelial growth factor (VEGF), nitric oxide synthases (NOS), nuclear factor kappa B (NF-&#954;B) and heat shock proteins (HSP-32: heme-oxygenase 1 (HO-1) and HSP-70) have been shown to play a role in tissue protection. Based on this chamber flap model, two modifications have been developed in order to analyze neovascularization and microcirculation during skin graft healing27 and angiogenic developments in a pedicled flap with axial pattern perfusion28. We present a reproducible and reliable model that includes an ischemically challenged musculocutaneous flap in the mouse skinfold chamber. This model allows visualization and quantification of the microcirculation and hemodynamics by intravital epi-fluorescence microscopy.

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			<td height="21" style="height:21px;width:319px;"><a name="RANGE!A1:D55">Name of Reagent/ Equipment</a></td>
			<td style="width:244px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:931px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">C57Bl/6 mice 6-8w 20-22g</td>
			<td style="width:244px;">Charles River</td>
			<td style="width:119px;"></td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:319px;">depilation cream</td>
			<td style="width:244px;">Veet</td>
			<td style="width:119px;"></td>
			<td>any depilation cream</td>
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			<td height="21" style="height:21px;width:319px;">titanium chamber</td>
			<td style="width:244px;">Irola</td>
			<td align="right" style="width:119px;">160001</td>
			<td>Halteblech M</td>
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			<td height="21" style="height:21px;width:319px;">slotted cheese head screw</td>
			<td style="width:244px;">Screws and More</td>
			<td align="right">842210</td>
			<td>DIN84 M2x10</td>
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			<td height="21" style="height:21px;width:319px;">hexagon full nut</td>
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			<td align="right">93422</td>
			<td>DIN934 M2</td>
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			<td height="21" style="height:21px;width:319px;">snap ring</td>
			<td style="width:244px;">Schaefer-Peters</td>
			<td align="right">472212</td>
			<td>DIN472 J12x1,0</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:319px;">cover glass</td>
			<td style="width:244px;">Volab</td>
			<td style="width:119px;"></td>
			<td>custom-made cover glass 11,8mm in diameter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">fixing foam</td>
			<td style="width:244px;">tesamoll</td>
			<td>05559-100</td>
			<td>tesamoll Standard I-Profile</td>
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			<td height="21" style="height:21px;width:319px;">ketamine hydrochloride</td>
			<td style="width:244px;">Parke Davis</td>
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			<td>Ketavet&#174;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">dihydroxylidinothiazine hydrochloride</td>
			<td style="width:244px;">Bayer</td>
			<td style="width:119px;"></td>
			<td>Rompun&#174;</td>
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			<td height="21" style="height:21px;width:319px;">Buprenorphin</td>
			<td style="width:244px;">Essex Pharma</td>
			<td style="width:119px;"></td>
			<td>Temgesic&#174;</td>
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			<td height="21" style="height:21px;width:319px;">Saline 0,9%</td>
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			<td height="21" style="height:21px;width:319px;">desinfection alcohol</td>
			<td style="width:244px;"></td>
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			<td></td>
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			<td height="21" style="height:21px;width:319px;">Vicryl 5-0</td>
			<td style="width:244px;">Ethicon</td>
			<td style="width:119px;">V 490 H</td>
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			<td height="21" style="height:21px;width:319px;">Ethilon 5-0</td>
			<td style="width:244px;">Ethicon</td>
			<td style="width:119px;">EH 7823 H</td>
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			<td height="21" style="height:21px;width:319px;">1ml syringes</td>
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			<td height="21" style="height:21px;width:319px;">surgical skin marker with flexible ruler</td>
			<td style="width:244px;">Purple surgical</td>
			<td>PS3151</td>
			<td>any surgical skin marker and flexible ruler</td>
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			<td height="21" style="height:21px;width:319px;">pointed scissors</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:319px;">Micro-Scissors</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:319px;">normal scissors</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:319px;">2 clamps</td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">fine anatomic forceps</td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">micro-forceps</td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;"></td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">hex nuter driver</td>
			<td style="width:244px;">wiha</td>
			<td>1018</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">screwdriver</td>
			<td style="width:244px;">wiha</td>
			<td style="width:119px;">685</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">snap ring plier</td>
			<td style="width:244px;">Knipex</td>
			<td style="width:119px;">4411J1</td>
			<td>12-25mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">wire cutter</td>
			<td style="width:244px;">Knipex</td>
			<td style="width:119px;">70 02 160</td>
			<td>Wire cutter is used to cut screws short; 160mm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;"></td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">trans-illumination light</td>
			<td style="width:244px;">IKEA</td>
			<td>501.632.02</td>
			<td>LED light Jansj&#246;; any light&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">magnification glasses</td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;"></td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">intravital microscope</td>
			<td style="width:244px;">Zeiss</td>
			<td>490035-0001-000</td>
			<td>Scope.A1.Axiotech</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">LED system</td>
			<td style="width:244px;">Zeiss</td>
			<td>423052-9501-000</td>
			<td>Colibri.2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">LED module 365nm</td>
			<td style="width:244px;">Zeiss</td>
			<td>423052-9011-000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">LED module 470nm</td>
			<td style="width:244px;">Zeiss</td>
			<td>423052-9052-000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">LED module 540-580nm</td>
			<td style="width:244px;">Zeiss</td>
			<td>423052-9121-000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">Filter set 62 62 HE BFP + GFP + HcRed</td>
			<td style="width:244px;">Zeiss</td>
			<td>489062-9901-000</td>
			<td>range 1: 350-390nm excitation wavelength split 395 / 402-448nm; range 2: 460-488nm, split 495nm / 500-557nm; range 3: 567-602nm, split 610nm / 615-infinite</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">Filter set 20 Rhodamine</td>
			<td style="width:244px;">Zeiss</td>
			<td>485020-0000-000</td>
			<td>540-552nm, split 560, emission 575-640nm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">2,5x objective NA=0,06</td>
			<td style="width:244px;">Zeiss</td>
			<td>421020-9900-000</td>
			<td>A-Plan 2,5x/0.06</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">5x objective NA=0,16</td>
			<td style="width:244px;">Zeiss</td>
			<td>420330-9901-000</td>
			<td>EC Plan-Neofluar 5x/0.16 M27</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">10x objetive NA=0,30</td>
			<td style="width:244px;">Zeiss</td>
			<td>420340-9901-000</td>
			<td>EC Plan-Neofluar 10x/0.30 M27</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">20x objective NA=0.50</td>
			<td style="width:244px;">Zeiss</td>
			<td>420350-9900-000</td>
			<td>EC Plan-Neofluar 20x/0.50 M27</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">50x objective NA=0,55</td>
			<td style="width:244px;">Zeiss</td>
			<td>422472-9960-000</td>
			<td>LD Epiplan-Neofluar 50x/0.55 DIC 27</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;"></td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">ZEN imaging software</td>
			<td style="width:244px;">Zeiss</td>
			<td style="width:119px;"></td>
			<td>ZenPro 2012</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">CapImage</td>
			<td style="width:244px;">Dr. Zeintl</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;"></td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">Fluorescein isothiocyanate-dextran</td>
			<td style="width:244px;">Sigma-Aldrich</td>
			<td style="width:119px;">45946</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">bisBenzimide H 33342 trihydrochloride</td>
			<td style="width:244px;">Sigma-Aldrich</td>
			<td style="width:119px;">B2261</td>
			<td>harmful if swallowed; causes severe skin burns and eye damage, may cause repiratory irritat</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">Rhodamine 6G chloride</td>
			<td style="width:244px;">Invitrogen</td>
			<td style="width:119px;">R634</td>
			<td>harmful if swallowed; may cause genetic defects; may cause cancer; may damage fertility or the unborn child</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:319px;"></td>
			<td style="width:244px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:319px;">Pentobarbital</td>
			<td style="width:244px;">Merial</td>
			<td style="width:119px;"></td>
			<td>Narcoren&#174;</td>
		</tr>
	</tbody>
</table>

ischemic tissue injury in the dorsal skinfold chamber of the mouse: a skin flap model to investigate acute persistent ischemia

Despite profound expertise and advanced surgical techniques, ischemia-induced complications ranging from wound breakdown to extensive tissue necrosis are still occurring, particularly in reconstructive flap surgery. Multiple experimental flap models have been developed to analyze underlying causes and mechanisms and to investigate treatment strategies to prevent ischemic complications. The limiting factor of most models is the lacking possibility to directly and repetitively visualize microvascular architecture and hemodynamics. The goal of the protocol was to present a well-established mouse model affiliating these before mentioned lacking elements. Harder et al. have developed a model of a musculocutaneous flap with a random perfusion pattern that undergoes acute persistent ischemia and results in ~50% necrosis after 10 days if kept untreated. With the aid of intravital epi-fluorescence microscopy, this chamber model allows repetitive visualization of morphology and hemodynamics in different regions of interest over time. Associated processes such as apoptosis, inflammation, microvascular leakage and angiogenesis can be investigated and correlated to immunohistochemical and molecular protein assays. To date, the model has proven feasibility and reproducibility in several published experimental studies investigating the effect of pre-, peri- and postconditioning of ischemically challenged tissue.

Necrosis
The main endpoint of this model&#160;&#8212; tissue necrosis following flap elevation (i.e., induction of acute persistent ischemia) &#8212; is repeatedly measured and illustrated macroscopically as shown in Figure 3 over a period of 10 days. Final demarcation of flap necrosis usually occurs between day 5 and 7 after surgery and is characterized by a red fringe, i.e., zone of vasodilation and microvascular remodeling, developing betw...

Watch this Scientific Journal Video about Ischemic Tissue Injury in the Dorsal Skinfold Chamber of the Mouse: A Skin Flap Model to Investigate Acute Persistent Ischemia at JoVE.com

Ischemic Tissue Injury in the Dorsal Skinfold Chamber of the Mouse: A Skin Flap Model to Investigate Acute Persistent Ischemia

The window of the murine dorsal skinfold chamber presented visualizes a zone of acute persistent ischemia of a musculocutaneous flap. Intravital epi-fluorescence microscopy permits for direct and repetitive assessment of the microvasculature and quantification of hemodynamics. Morphologic and hemodynamic results can further be correlated with histological and molecular analyses.

Despite profound expertise and advanced surgical techniques, ischemia-induced complications ranging from wound breakdown to extensive tissue necrosis are ...

Research

JoVE Journal

Medicine

In situ Transverse Rectus Abdominis Myocutaneous Flap: A Rat Model of Myocutaneous Ischemia Reperfusion Injury

In situ Transverse Rectus Abdominis Myocutaneous Flap: A Rat Model of Myocutaneous Ischemia Reperfusion Injury

Free tissue transfer is the gold standard of reconstructive surgery to repair complex defects not amenable to local options or those requiring composite ...

Ischemia-reperfusion Model of Acute Kidney Injury and Post Injury Fibrosis in Mice

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often ...

A Murine Model of Myocardial Ischemia-reperfusion Injury through Ligation of the Left Anterior Descending Artery

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms ...

Demonstration of the Rat Ischemic Skin Wound Model

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Open Tracheostomy Gastric Acid Aspiration Murine Model of Acute Lung Injury Results in Maximal Acute Nonlethal Lung Injury

Acid pneumonitis is a major cause of sterile acute lung injury (ALI) in humans. Acid pneumonitis spans the clinical spectrum from asymptomatic to acute ...

Inducing Ischemia-reperfusion Injury in the Mouse Ear Skin for Intravital Multiphoton Imaging of Immune Responses

Ischemia-reperfusion injury (IRI) occurs when there is transient hypoxia due to the obstruction of blood flow (ischemia) followed by a subsequent ...

A Model of Free Tissue Transfer: The Rat Epigastric Free Flap

Free tissue transfer has been increasingly used in clinical practice since the 1970s, allowing reconstruction of complex and otherwise untreatable defects ...

Modified Heterotopic Hindlimb Osteomyocutaneous Flap Model in the Rat for Translational Vascularized Composite Allotransplantation Research

Vascularized composite allotransplantation (VCA) is a relatively new field in the reconstructive surgery. Clinical achievements in human VCA include hand ...

Scratch Migration Assay and Dorsal Skinfold Chamber for In Vitro and In Vivo Analysis of Wound Healing

Impaired cutaneous wound healing is a major concern for patients suffering from diabetes and for elderly people, and there is a need for an effective ...

A Pre-clinical Rat Model for the Study of Ischemia-reperfusion Injury in Reconstructive Microsurgery

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many ...