Creation of Colonic Anastomosis in Mice

Summary

Anastomotic leak or breakdown after surgery is a major cause of postoperative morbidity and mortality. Our surgery for creating a colonic anastomosis is a reliable and reproducible method for studying the healing mechanisms of anastomoses.

Abstract

Intestinal anastomoses are commonly performed in both elective and emergent operations. Even so, anastomotic leaks are a highly feared complications of colonic surgeries and can occur in up to 26% of surgical anastomoses, with mortality being up to 39% for patients with such a leak. Currently, there remains a paucity of data detailing the cellular mechanisms of anastomotic healing. Devising preventative strategies and treatment modalities for anastomotic leak could be greatly potentiated by a better understanding of appropriate anastomotic healing.

A murine model is ideal as previous studies have shown that the murine anastomosis is the most clinically similar to the human case as compared with other animal models. We offer an easily reproducible murine model of colonic anastomosis in mice that will allow for further illustration of anastomotic healing.

Introduction

A highly feared complication of surgical anastomosis of the intestine is anastomotic breakdown or leak. Anastomotic leak, which causes spillage of the intraluminal contents into the abdominal cavity, is life threatening and can quickly lead to intra-abdominal sepsis; shock rates vary from 0.3% to 5.5% following small bowel anastomoses, and rise to between 0.5% and 26% for colonic anastomoses^1,2. Mortality rates following leaks can be as high as 39% due to the swift onset of sepsis and rapid progression to death following intraabdominal contamination³. Preventative strategies and treatme....

Protocol

The following protocol has been approved by the University of Oklahoma Health Sciences Center Institutional Animal Care and Use Committee (IACUC) and complies with all institutional ethical guidelines regarding the use of research animals. Additionally, all experiments were performed in accordance with institutional, state and federal regulations regarding experimental animal research.

NOTE: For this protocol, we used female and male congenic in-bred C57BL6/J mice at 12 to 72 weeks of age. All mice used for this procedure were kept at our non-barrier facility for at least one week prior to the operation to adapt to the local biome. Animals ....

Results

At 7 days following surgery, the anastomosis should be well healed. The anastomosis can be harvested at time points before and after seven days to better illustrate the stages of anastomotic healing. In Figure 9, the histological analysis shows a fibrotic (collagen visualized by trichrome staining) response mediated by smooth muscle alpha-actin positive myofibroblasts. However, we have found that results from histological analyses vary between mice, specifica.......

Discussion

There are several key steps to ensure the success of and minimize the morbidity/mortality associated with this procedure. First, ensure careful handling of intestinal tissue and take care to prevent traction injury when rotating the viscera to expose the colon. Undue tension on the bowel or mesentery can injury the bowel or vasculature and cause bowel necrosis away from the site of anastomosis. Additionally, sharp forceps or forceps with teeth should not be used to handle the bowel.

Injury to .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
C57BL6/J mice	Jackson Labs	#00664
Fisherbrand Absorbent Underpads, 20" x 24"	Fisher Scientific	14-206-62
Polylined Sterile Field, 18" x 24"	Busse Hospital Disposables	696	Cut a rectangular hole
Isothesia isoflurane	Henry Schein	50033
Fisherbrand Sterile cotton gauze pad, 4" x 4"	Fisher Scientific	22-415-469
Puralube petrolatum ophthalmic ointment, 1/8 oz. tube	Dechra Veterinary Products	NDC 17033-211-38
Nair depilatory cream	Church & Dwight Co.	22339-05
Buprenex buprenorphine  0.3 mg/ml	Reckitt Benckiser Pharma Inc	NDC 12496-0757-5
1 cc insulin syringe, 27 G	Becton Dickinson	329412
Chloraprep Shampoo	Medline	APL82287
Webcol alcohol prep swabs	Covidien	6818
BioGel PI surgical gloves	Mölnlycke Health Care	ALA42675Z
Micro Forceps with teeth	Roboz	RS-5150
Fine scissors- sharp	Fine Science Tools	14060-09
Straight serrated forceps	Fine Science Tools	11050-10
Castro-Viejo needle driver	Fine Science Tools	12565-14
0.9% Sodium Chloride Irrigation	Baxter	BHL2F7121	Warm to 37 °C prior to use
10 ml syringe	Becton Dickinson	309604
4-0 Vicryl absorbable braided suture, 18", PS-2 needle	Henry Schein	6546037
Blue monofilament suture 24” BV-1 needle	Henry Schein	8305H	Usually comes double-armed. Cut the suture at the midway point to generate two usable sutures.
Cole-Parmer Microscissors, Standard Grade, Straight, 4".	Cole- Parmer	EW-10818-06
Medline Sterile lubricating jelly	Medline	MDS032273H