We would like to acknowledge the funding contributions of the Canadian Surgical Research Fund, the Edmonton Civic Employees Research Assistance Fund, and the Alberta IBD Consortium through a grant from Alberta Innovates.

Animal use protocols were approved by the Health Science Animal Care and Use committee at the University of Alberta.
1. Preparation of Instruments, Animals and Operative Setup
<ol>
	<li>Transfer animals to a new, clean cage absent of all solid food 24 hr prior to the procedure. They may have free access to water, and liquid diet ad lib until the time of the procedure.</li>
	<li>Autoclave all instruments required for the procedure. Clean operating surface and anesthetic nose cone with 70% eth...

<ol>
	<li>Hallet, J., Zih, F. S., Lemke, M., Milot, L., Smith, A. J., Wong, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neo-adjuvant+chemoradiotherapy+and+multivisceral+resection+to+optimize+R0+resection+of+locally+recurrent+adherent+colon+cancer.">Neo-adjuvant chemoradiotherapy and multivisceral resection to optimize R0 resection of locally recurrent adherent colon cancer.</a> European Journal of Surgical Oncology. 40 (6), (2014).</li><li>Rutgeerts, P., Geboes, K., Vantrappen, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Natural+history+of+recurrent+Crohn&#39;s+disease+at+the+ileocolonic+anastomosis+after+curative+surgery.">Natural history of recurrent Crohn&#39;s disease at the ileocolonic anastomosis after curative surgery.</a> Gut. 25 (6), 665-672 (1984).</li><li>Davis, D., Rivadeneira, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Complications+of+colorectal+anastomoses:+leaks,+strictures,+and+bleeding.">Complications of colorectal anastomoses: leaks, strictures, and bleeding.</a> The Surgical clinics of North America. 93 (1), 61-87 (2013).</li><li>Helmrath, M. A., VanderKolk, W. E., Can, G., Erwin, C. R., Warner, B. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intestinal+adaptation+following+massive+small+bowel+resection+in+the+mouse.">Intestinal adaptation following massive small bowel resection in the mouse.</a> Journal of the American College of Surgeons. 183 (5), 441-449 (1996).</li><li>Dekaney, C. M., Fong, J. J., Rigby, R. J., Lund, P. K., Henning, S. J., Helmrath, 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=Expansion+of+intestinal+stem+cells+associated+with+long-term+adaptation+following+ileocecal+resection+in+mice.+American+journal+of+physiology.">Expansion of intestinal stem cells associated with long-term adaptation following ileocecal resection in mice. American journal of physiology.</a> Gastrointestinal and liver physiology. 293 (5), (2007).</li><li>Speck, K. E., De Cruz, 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=Inflammation+enhances+resection-induced+intestinal+adaptive+growth+in+IL-10+null+mice.">Inflammation enhances resection-induced intestinal adaptive growth in IL-10 null mice.</a> The Journal of surgical research. 168 (1), 62-69 (2011).</li><li>Rigby, R. J., Hunt, M. R., 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=A+new+animal+model+of+postsurgical+bowel+inflammation+and+fibrosis:+the+effect+of+commensal+microflora.">A new animal model of postsurgical bowel inflammation and fibrosis: the effect of commensal microflora.</a> Gut. 58 (8), 1104-1112 (2009).</li><li>Kostic, A. D., Xavier, R. J., Gevers, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Microbiome+in+Inflammatory+Bowel+Disease:+Current+Status+and+the+Future+Ahead.">The Microbiome in Inflammatory Bowel Disease: Current Status and the Future Ahead.</a> Gastroenterology. , 1-11 (2014).</li><li>Gevers, D., Kugathasan, 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=The+Treatment-Naive+Microbiome+in+New-Onset+Crohn&#39;s+Disease.">The Treatment-Naive Microbiome in New-Onset Crohn&#39;s Disease.</a> Cell host &amp; microbe. 15 (3), 382-392 (2014).</li><li>Ahmed, T., Rieder, F., Fiocchi, C., Achkar, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathogenesis+of+postoperative+recurrence+in+Crohn&#39;s+disease.">Pathogenesis of postoperative recurrence in Crohn&#39;s disease.</a> Gut. 60 (4), 553-562 (2011).</li><li>Borowiec, A., Sydora, B., 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=Small+bowel+fibrosis+and+systemic+inflammatory+response+after+ileocolonic+anastomosis+in+IL-10+null+mice.">Small bowel fibrosis and systemic inflammatory response after ileocolonic anastomosis in IL-10 null mice.</a> Journal of Surgical Research. 178 (1), 147-154 (2012).</li><li>Devine, A. A., Gonzalez, 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=.">.</a> Impact of Ileocecal Resection and Concomitant Antibiotics on the Microbiome of the Murine Jejunum and Colon. 8 (8), (2013).</li><li>Bij, G. J., Oosterling, S. J., Beelen, R. H. J., Meijer, S., Coffey, J. C., van Egmond, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+perioperative+period+is+an+underutilized+window+of+therapeutic+opportunity+in+patients+with+colorectal+cancer.">The perioperative period is an underutilized window of therapeutic opportunity in patients with colorectal cancer.</a> Annals of surgery. 249 (5), (2009).</li><li>Scott, A. D., Uff, C., Phillips, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Suppression+of+macrophage+function+by+suture+materials+and+anastomotic+recurrence+of+Crohn&#39;s+disease.">Suppression of macrophage function by suture materials and anastomotic recurrence of Crohn&#39;s disease.</a> The British journal of surgery. 80 (3), (1993).</li><li>Kiernan, 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=Intestinal+anastomosis+in+the+rat+facilitated+by+a+rapidly+digested+internal+splint+and+indigestible+but+absorbable+sutures.">Intestinal anastomosis in the rat facilitated by a rapidly digested internal splint and indigestible but absorbable sutures.</a> Journal of Surgical Research. 45, 427-431 (1988).</li><li>Andersen, T. L., 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=Action+of+matrix+metalloproteinases+at+restricted+sites+in+colon+anastomosis+repair:+an+immunohistochemical+and+biochemical+study.">Action of matrix metalloproteinases at restricted sites in colon anastomosis repair: an immunohistochemical and biochemical study.</a> Surgery. 140 (1), 72-82 (2006).</li><li>Thompson, S. K., Chang, E. Y., Jobe, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+review:+Healing+in+gastrointestinal+anastomoses,+Part+I.">Clinical review: Healing in gastrointestinal anastomoses, Part I.</a> Microsurgery. 26 (3), 131-136 (2006).</li></ol>

The murine ICR is a powerful model that can be used to study the effects of surgery in bowel diseases. This article describes a method of performing ICR in mice with a success rate of 95% and no issues with failure to thrive as reflected by stable weights up to 28 days post-procedure. The most significant challenges to successful ICR include avoiding bowel obstructions at the anastomosis and anastomotic leaks.
Technical elements to the surgery for preventing obstruction are aimed at maximizing...

Ileocolic resection (ICR) is a common procedure performed in both emergent and elective situations for a variety of illnesses. Crohn&#8217;s disease and colon cancers are the two most common indications for ICR. In both illnesses, recurrence in the bowel at the site of surgery represents a major clinical problem. Local recurrence rates for colon cancer remain an issue even with the most aggressive resections1. Following ICR in Crohn&#8217;s disease, the disease most frequently (in up to 80%) recurs in the neo-terminal ileum at 1 year after surgery2. Given the impact of these two illnesses and their recurrence after surgery, it is important to understand local intestinal factors after ICR, which may have intrinsic influences on the natural history of these diseases. Further, it is also important to consider anastomotic healing after ICR. In the early post-operative period, anastomotic leaks can have devastating consequences for patients resulting in repeat surgeries, stoma creations, significant morbidity, and even mortality3. Despite the importance of this topic, our current understanding of anastomotic healing remains in its infancy as a subject of research. Animal models of ICR, in particular mice, are an excellent platform for studying the intestinal and anastomotic healing following surgery.
A mouse model of ICR was initially developed by Helmrath et al. to be used as a model of short gut syndrome4. The authors experimented with various diet regiments and suture sizes to optimize animal survival following ICR. They concluded that feeding with liquid diet in the perioperative period and using 9-0 monofilament sutures resulted in an optimal post-operative survival of 88%. Since this initial publication, ICR in mice removing 50% of the small bowel has been used in several studies to explore the dynamics of massive small bowel resection and the adaptive growth response in attempt to develop new therapies for short gut syndrome5,6.
The first application of the ICR mouse model to Crohn&#8217;s disease used the IL-10-/- mouse model, which spontaneously develops colitis7. The authors found that after ICR these animals developed inflammation in the neo-terminal ileum similar to that seen in post-operative Crohn&#8217;s disease patients, and that this inflammation was dependent on the presence of bacteria7. More recently, this model was used to explore bacterial changes induced by ICR. In Crohn&#8217;s disease there is an associated dysbiosis with relative decreases in bacteria known to have anti-inflammatory properties and increases in invasive species of bacteria8,9. The association holds true in cases of post-operative recurrence10. Two studies sought to identify microbial changes resulting from ICR. The first used IL-10 null mice, and performed denaturing gel electrophoresis to compare bacterial similarity between the small bowel and colon after ICR11. This study demonstrated that bacterial populations became similar in the small intestine and colon following ICR. A subsequent study used wild type mice and 16s pyrosequencing for phylogenetic classification of bacterial species post-operatively. This study demonstrated a marked shift in bacterial species resulting from surgery alone with Clostridium species becoming dominant as well as an increase in &#978;-proteobacteria. The results also confirmed the findings of the previous study with similar populations found in the small bowel and colon after ICR12. 
ICR is a common procedure for patients with colon cancer involving the cecum and ascending colon, and it is becoming increasingly recognized that the host-response to surgery likely contributes to both local and distant tumor recurrence13. Despite this observation, models of ICR have not been utilized for the study of colorectal cancer and post-operative recurrence. Understanding both the systemic and local immunologic changes resulting from ICR will be important in investigating future therapies. Potential pathways involved in cancer recurrence post ICR include up regulation of growth factors, which may rescue cells from apoptosis and stimulate proliferation, mechanical tumor disruption with cell shedding, and loss of immune surveillance through post-operative immunosuppression13,14. 
Mouse models of ICR have the potential to be a powerful tool for the investigation of short bowel syndrome, Crohn&#8217;s disease, and colon cancer. They may also provide lessons on how to prevent early post-operative anastomotic complications by further defining the cellular and biochemical pathways involved in healing the newly constructed anastomosis. A major barrier in utilizing the murine ICR model is the technical difficulty. The intestinal anastomosis requires the use of 8-0 or 9-0 suture, an operating microscope, and training in microsurgical techniques. The goal of this article is to provide clear instructions on how to perform ICR in mice with the goal of utilizing this procedure in models of disease.

<table border="0" cellpadding="0" cellspacing="0" width="665">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Name of Material/ Equipment</td>
			<td style="width:163px;">Company</td>
			<td style="width:119px;">Catalog Number</td>
			<td style="width:167px;">Comments/Description</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">LD101 liquid rodent diet</td>
			<td style="width:163px;">testdiet.com</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">0.9% NaCl</td>
			<td>Baxter</td>
			<td>FKE1324</td>
			<td>Injection quality saline</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Operating Microscope</td>
			<td>Ziess</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isoflurane Anesthetic Vaporizer</td>
			<td>Harvard Apparatus</td>
			<td>34-0483</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Isoflurane</td>
			<td>Abbott&#160;</td>
			<td>05260-05</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Glass plate</td>
			<td></td>
			<td></td>
			<td>For operating surface</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Cotton swabs</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Micro Castroviejo Needle holder, curved</td>
			<td>World Precision Instruments</td>
			<td align="right">503377</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Castroviejo straight scissors</td>
			<td>World Precision Instruments</td>
			<td>555530S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dissecting Scissors</td>
			<td>World Precision Instruments</td>
			<td align="right">15922</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dressing Forceps x 2</td>
			<td>World Precision Instruments</td>
			<td align="right">500363</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">5-0 silk pre-cut sutures</td>
			<td>Ethicon</td>
			<td>A182H</td>
			<td>For vessel ligation</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">8-0 Prolene on BV130-5 needle</td>
			<td>Ethicon</td>
			<td>8732H</td>
			<td>For anastomosis</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">3-0 Silk on FS-2 needls</td>
			<td>Ethicon</td>
			<td>8665G</td>
			<td>For abdominal wall closure</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Petroleum Jelly</td>
			<td>Vaseline</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10 ml syringe</td>
			<td>BD biosciences</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Povidone-iodine 7.5% surgical Scrub</td>
			<td><a href="http://betadine.com">betadine.com</a></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Heat lamps</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">buprenorphine 0.3 mg/ml</td>
			<td>Reckitt Benckiser Healthcare Ltd.&#160;</td>
			<td>PL36699/0006</td>
			<td></td>
		</tr>
	</tbody>
</table>

murine ileocolic bowel resection with primary anastomosis

Intestinal resections are frequently required for treatment of diseases involving the gastrointestinal tract, with Crohn&#8217;s disease and colon cancer being two common examples. Despite the frequency of these procedures, a significant knowledge gap remains in describing the inherent effects of intestinal resection on host physiology and disease pathophysiology. This article provides detailed instructions for an ileocolic resection with primary end-to-end anastomosis in mice, as well as essential aspects of peri-operative care to maximize post-operative success. When followed closely, this procedure yields a 95% long-term survival rate, no failure to thrive, and minimizes post-operative complications of bowel obstruction and anastomotic leak. The technical challenges of performing the procedure in mice are a barrier to its wide spread use in research. The skills described in this article can be acquired without previous surgical experience. Once mastered, the murine ileocolic resection procedure will provide a reproducible tool for studying the effects of intestinal resection in models of human disease.

Mortality rates and weight change post-op. 
Mortality rates following ICR in 129S1 wild type mice are generally ~ 5%. The most common cause of morality is bowel obstruction at the anastomosis. Other causes of mortality include anastomotic leak and internal hernia leading to bowel obstruction.
Weight loss can be seen up to 14 days post-operatively, but is generally non-significant. Mice tend to completely regain pre-operative weight by post-operative day 28 (Figure&#160;2<...

Watch this Scientific Journal Video about Murine Ileocolic Bowel Resection with Primary Anastomosis at JoVE.com

Murine Ileocolic Bowel Resection with Primary Anastomosis

Ileocolic resection is commonly performed in several human diseases; however, little is known regarding the impact of intestinal resection on surgical illnesses. This article provides instruction on executing the procedure in mice with high success, providing a means to study the effects of ileocolic resection in models of disease.

Intestinal resections are frequently required for treatment of diseases involving the gastrointestinal tract, with Crohn&#8217;s disease and colon cancer ...

murine-ileocolic-bowel-resection-with-primary-anastomosis

Research

JoVE Journal

Medicine

16.2K Views.  University of Alberta. Ileocolic resection is commonly performed in several human diseases; however, little is known regarding the impact of intestinal resection on surgical illnesses. This article provides instruction on executing the procedure in mice with high success, providing a means to study the effects of ileocolic resection in models of disease.