Murine Ileocolic Bowel Resection with Primary Anastomosis

The overall goal of this procedure is to resect the terminal ileum and cecum and perform an IOC colic anastomosis. This is accomplished by first ligating, the ileocecal blood supply. The second step is to remove the ischemic portion of intestine.

Next, the IOC colic anastomosis is constructed. The final step is to inspect the anastomosis for integrity and patency. Ultimately, the effects of IOC colic.

Resection may be determined in various models of disease. So visual demonstration of this method is critical because the resection and anastomosis require a high level of anatomical detail. To begin transfer animals to a new clean cage, absent of all solid food for 24 hours, allow free access to water and liquid diet until the time of the procedure.

Autoclave all instruments required for the procedure ahead of time and clean the operating surface and anesthetic nose cone with 70%ethanol. Next, arrange an operating microscope anesthetic machine, and surgical supplies comfortably within the working area. Instruments, sutures, cotton swabs, and a 10 milliliter syringe should be placed in a location that permits easy access while working.

Set up an overhead heat lamp to provide warmth during the procedure and light for the operating surface. Finally, fill a 50 milliliter conical tube with 0.9%saline and a 1.5 milliliter tube with petroleum jelly and place near the operating surface. When ready to begin, confirm the depth of sedation in an anesthetized mouse.

Once fully anesthetized, turn down the isof fluorine and oxygen flow rate. Periodically check the pain response during the procedure and adjust the isof fluorine flow Rate accordingly. After applying petroleum jelly to the eyes, immobilize the mouse in the supine position with limb secured using transparent tape.

Next, clean the abdomen with povidone iodine solution. Afterwards, change into new sterile gloves. Make a 1.5 centimeter incision in the upper midline of the abdomen to expose the fascia and peritoneum once exposed, cut through the linear alba to expose the peritoneal contents.

In contrast to humans, the mouse seum is typically found in the left upper quadrant of the abdomen. Once identified, gently grasp the cecum with forceps and deliver it through the incision. Place sterile gauze on the abdominal surface and use moistened cotton swabs to fan out approximately three centimeters of terminal ileum extending from the cecum.

Ensure the exposed bowel is kept moist with 0.9%saline during the entirety of the procedure. Using an operating microscope, identify the ileocecal artery branching off the superior mesenteric artery along the colon. Dissect out the avascular tissues adjacent to the ileocecal artery.

Once isolated, and circle and ligate the artery with a 5.0 silk tie. Next, locate the regional blood supply to the terminal ileum and choose a transection 0.1 0.5 to two centimeters proximal to the ileocecal junction. Ligate the branches to this section of ileum as shown earlier, divide the arteries with micro dissecting scissors.

Remove the ischemic portions of ileum and colon and ensure there is adequate blood supply to the transected ends. It is often helpful to spatulate the ileum by dividing it at a 30 degree angle to increase the diameter of the lumen so it more closely matches the colon. Next, align the transected ends of ileum and colon on the gauze, ensuring the mesenteric borders of each are aligned.

Construct the anastomosis by approximating the transected end of ileum to the transected end of colon. Using interrupted eight oh polypropylene sutures, the first stitch should be placed at the mesenteric border with subsequent sutures placed every 0.5 millimeters until the IOC colic. Anastomosis is watertight.

When passing the suture needle through the ileum and colon, ensure that the cut edge is not rolled, and that needle bites are 0.5 millimeters from the cut edges of the bowel. A typical anastomosis will require 14 to 16 interrupted sutures. Test the integrity and patency of the anastomosis upon completion by rolling a cotton swab proximal to distal over the ileum.

To force contents through small bowel contents should freely pass into the colon without anastomotic leakage. Rinse the exposed bowel with three to four milliliters of 0.9%saline from the 10 milliliter syringe to wash away stool from the surface of the bowel before delivering the bowel back into the peritoneal cavity. Using two milliliters of 0.9%saline.

Flush the peritoneal cavity. Drain this fluid by applying gentle pressure to the abdominal wall laterally. Close the incision with a 3.0 silk running suture.

Discontinue the flow of isoflurane and administer an analgesic for postoperative pain control. Observe the animals under the heat lamp until they're mobile, then transfer them to a continually warmed cage. Monitor animals in a continually warmed cage for signs of distress.

For the remainder of the day, transfer animals back to the animal care facility in a new sterile cage with access to liquid diet and water, add libido. Check the animals in the morning of postoperative day one. If they appear uncomfortable, administer another dose of buprenorphine by postoperative day two.

They should appear fully recovered. Stooling and food consumption are positive signs of recovery. If this is observed, then they can resume a solid chow diet.

Once again, Body weight was not significantly different between groups when comparing baseline to postoperative day 14 and 28. The h and d stained histologic sections of ileum and colon are lined up to demonstrate the trajectory of the suture needle through the tissues starting at point A through to point B.The knot should be tied at point C, So once mastered, this technique can be performed in approximately 45 minutes if conducted properly.