This study was supported in part by NIH grants 1RO1DK74566 and 1RO1AM52984. The authors would like to thank Ms. Jacqueline McCarty in RRC for her help during surgery, Drs. Jianpu Wang and Harshini Sarojini for their help in surgery and postoperative care of some rabbits, Dr. Rong Wan for her histology work, and Ms. Ming Li for her HPLC measurements of high-energy phosphates.

1. Anatomic Basis
The rabbit ear has been a favored study material for wound care since the early 20th century. The ear is supplied by three vascular bundles (central, cranial, and caudal); the central bundle is the largest, while the vessels in the cranial and caudal bundles vary in size. Occasionally, the caudal artery may be absent.1 All of these vessels are easily identified on the dorsal side after the ear is shaved (Fig. 1). On the ventral side, the d...

<ol>
	<li>Ninomiya, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+vascular+bed+in+the+rabbit+ear:+microangiography+and+scanning+electron+microscopy+of+vascular+corrosion+casts.">The vascular bed in the rabbit ear: microangiography and scanning electron microscopy of vascular corrosion casts.</a> Anat. Histol. Embryol. 29, 301-305 (2000).</li><li>Sen, C. K., Gordillo, G. M., Roy, S., Kirsner, R., Lambert, L., Hunt, T. K., Gottrup, F., Gurtner, G. C., Longaker, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+skin+wounds:+a+major+and+snowballing+threat+to+public+health+and+the+economy.">Human skin wounds: a major and snowballing threat to public health and the economy.</a> Wound Repair. 17, 763-771 (2009).</li><li>Boulton, A. J., Vileikyte, L., Ragnarson-Tennvall, G., Apelqvist, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+global+burden+of+diabetic+foot+disease.">The global burden of diabetic foot disease.</a> Lancet. 366, 1719-1724 (2005).</li><li>Edwards, J., Stapley, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Debridement+of+diabetic+foot+ulcers.">Debridement of diabetic foot ulcers.</a> Cochrane Database Syst. Rev. 1, 1-40 (2010).</li><li>Werdin, F., Tennenhaus, M., Schaller, H. E., Rennekampff, H. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evidence-based+Management+Strategies+for+Treatment+of+Chronic+Wounds.">Evidence-based Management Strategies for Treatment of Chronic Wounds.</a> Eplasty. 9, 169-179 (2009).</li><li>Wu, Y., Chen, L., Scott, P. G., Tredget, E. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesenchymal+stem+cells+enhance+wound+healing+through+differentiation+and+angiogenesis.">Mesenchymal stem cells enhance wound healing through differentiation and angiogenesis.</a> Stem Cells. 25, 2648-2659 (2007).</li><li>Bennett, J. P., Matthews, R., Faulk, W. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+chronic+ulceration+of+the+legs+with+human+amnion.">Treatment of chronic ulceration of the legs with human amnion.</a> Lancet. 1, 1153-1156 (1980).</li><li>Gottrup, F., Agren, M. S., Karlsmark, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Models+for+use+in+wound+healing+research:+a+survey+focusing+on+in+vitro+and+in+vivo+adult+soft+tissue.">Models for use in wound healing research: a survey focusing on in vitro and in vivo adult soft tissue.</a> Wound Repair. 8, 83-96 (2000).</li><li>Lindblad, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+in+wound+healing+research:+do+we+need+more.">Animal models in wound healing research: do we need more.</a> Wound Repair. 8, 81-82 (2000).</li><li>LoGerfo, F. W., Gibbons, G. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+disease+of+the+lower+extremities+in+diabetes+mellitus.">Vascular disease of the lower extremities in diabetes mellitus.</a> Endocrinol. Metab. Clin. North Am. 25, 439-445 (1996).</li><li>Gottrup, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxygen,+wound+healing+and+the+development+of+infection.+Present+status.">Oxygen, wound healing and the development of infection. Present status.</a> Eur. J. Surg. 168, 260-263 (2002).</li><li>Niinikoski, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+blood+and+oxygen+supply+on+the+biochemistry+of+repair.">The effect of blood and oxygen supply on the biochemistry of repair.</a> , 56-71 (2002).</li><li>Schaffer, M., Witte, M., Becker, H. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Models+to+study+ischemia+in+chronic+wounds.">Models to study ischemia in chronic wounds.</a> Int. J. Low Extrem. Wounds. 1, 104-111 (2002).</li><li>Niinikoski, J., Gottrup, F., Hunt, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+oxygen+in+wound+repair.">The role of oxygen in wound repair.</a> , 165-174 (1991).</li><li>Harding, K. G., Morris, H. L., Patel, G. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Science,+medicine+and+the+future:+healing+chronic+wounds.">Science, medicine and the future: healing chronic wounds.</a> BMJ. 324, 160-163 (2002).</li><li>Lindblad, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Editorial:+How+should+one+study+wound+healing.">Editorial: How should one study wound healing.</a> Wound Repair. 14, 515-515 (2007).</li><li>Chien, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ischemic+rabbit+ear+model+created+by+minimally+invasive+surgery.">Ischemic rabbit ear model created by minimally invasive surgery.</a> Wound Repair Regen. 15, 928-935 (2007).</li><li>Joseph, J., Townsend, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+healing+of+defects+in+immobile+skin+in+rabbits.">The healing of defects in immobile skin in rabbits.</a> Br. J. Surg. 48, 557-564 (1961).</li><li>James, G. A., Swogger, E., Wolcott, R., Pulcini, E., Secor, P., Sestrich, J., Costerton, J. W., Stewart, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biofilms+in+chronic+wounds.">Biofilms in chronic wounds.</a> Wound Repair Regen. 16, 37-44 (2008).</li><li>Niitsuma, J., Yano, H., Togawa, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+study+of+decubitus+ulcer+formation+in+the+rabbit+ear+lobe.">Experimental study of decubitus ulcer formation in the rabbit ear lobe.</a> J. Rehabil. Res. Dev. 40, (2003).</li><li>Salcido, R., Popescu, A., Ahn, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+in+pressure+ulcer+research.">Animal models in pressure ulcer research.</a> J. Spinal Cord Med. 30, 107-116 (2007).</li></ol>

There is no financial conflict of interest involved in this study.

Diabetes affects 23.6 million people in the US,2,3 and 15-20% of these patients develop foot ulcers in their lifetime,4,5 at an annual treatment cost of more than $25 billion.3,6 However, even the best available treatments achieve only a 50% healing rate and this is often temporary,7 with recurrence rates as high as 66% in diabetics.3,6 When ulcers occur in diabetic patients, major complications such as infection and amputation increase dramatically. Despite almost a...

For monitoring during surgery
<ol>
 <li> A heating pad to maintain normal temperature. </li>
 <li>A transcutaneous oxygen monitor. </li>
 <li> A temperature monitor. </li>
</ol>
For surgery
<ol>
 <li> A #3 knife with #15 blade. </li>
 <li>Two pairs of forceps (one for skin and another for other soft tissues). </li>
 <li> 2-3 pairs of small clamps. </li>
 <li> One or two pairs of micro scissors (for tissue cutting). </li>
 <li>One pair of small scissors (for cutting sutures). </li>
 <li>A needle holder. </li>
 <li>A few stainless steel punches (for making wounds). </li>
</ol>

a simplified technique for producing an ischemic wound model

One major obstacle in current diabetic wound research is a lack of an ischemic wound model that can be safely used in diabetic animals. Drugs that work well in non-ischemic wounds may not work in human diabetic wounds because vasculopathy is one major factor that hinders healing of these wounds. We published an article in 2007 describing a rabbit ear ischemic wound model created by a minimally invasive surgical technique. Since then, we have further simplified the procedure for easier operation. On one ear, three small skin incisions were made on the vascular pedicles, 1-2 cm from the ear base. The central artery was ligated and cut along with the nerve. The whole cranial bundle was cut and ligated, leaving only the caudal branch intact. A circumferential subcutaneous tunnel was made through the incisions, to cut subcutaneous tissues, muscles, nerves, and small vessels. The other ear was used as a non-ischemic control. Four wounds were made on the ventral side of each ear. This technique produces 4 ischemic wounds and 4 non-ischemic wounds in one animal for paired comparisons. After surgery, the ischemic ear was cool and cyanotic, and showed reduced movement and a lack of pulse in the ear artery. Skin temperature of the ischemic ear was 1-10 &deg;C lower than that on the normal ear and this difference was maintained for more than one month. Ear tissue high-energy phosphate contents were lower in the ischemic ear than the control ear. Wound healing times were longer in the ischemic ear than in the non-ischemic ear when the same treatment was used. The technique has now been used on more than 80 rabbits in which 23 were diabetic (diabetes time ranging from 2 weeks to 2 years). No single rabbit has developed any surgical complications such as bleeding, infection, or rupture in the skin incisions. The model has many advantages, such as little skin disruption, longer ischemic time, and higher success rate, when compared to many other models. It can be safely used in animals with reduced resistance, and can also be modified to meet different testing requirements.

Watch this Scientific Journal Video about A Simplified Technique for Producing an Ischemic Wound Model at JoVE.com

A Simplified Technique for Producing an Ischemic Wound Model

We have developed a minimally invasive technique to create a rabbit ischemic ear wound model by dividing the central artery and nerve and the cranial neurovascular bundle. A subcutaneous tunnel then cuts all subcutaneous tissues. This procedure causes minimal skin disruption and can be safely used in diabetic animals.

One major obstacle in current diabetic wound research is a lack of an ischemic wound model that can be safely used in diabetic animals. Drugs that work ...

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17.1K Görüntüleme.  University of Louisville. Biz santral arter ve sinir ve beyin nörovasküler demet bölerek bir tavşan kulağı iskemik yara modeli oluşturmak için minimal invaziv bir teknik geliştirdik. Bir subkutan tünel sonra tüm cilt altı dokuları keser. Bu prosedür, minimal deri bozulmasına neden olmakta ve güvenli bir şekilde, diyabetik hayvanlarda kullanılabilir.