Author

Stephen J. Birchard DVM, MS, Diplomate ACVS

Saturday, October 19, 2013

Intestinal Anastomosis Made Simple: Description and Surgical Model Video


Intestinal resection and anastomosis is indicated for any bowel that is nonviable, neoplastic, perforated by a foreign body, intussuscepted, or has any other irreversible tissue damage. The principles of intestinal resection and anastomosis are:
- isolate the affected segment of intestine from the peritoneal cavity to prevent contamination
- keep the tissues moist and handle atraumatically
- use assistant’s fingers rather than forceps to occlude the bowel
- avoid excessively grabbing the intestine with thumb forceps and only grab the serosal layer
- remove all intestine that appears non-viable
- use a delayed absorbable, monofilament suture with a small swaged on needle (e.g. 4-0 PDS with an RB1 needle)
- take full thickness suture bites of the intestinal wall to assure penetration of the submucosa, which is the holding layer.
- wrap the anastomosis with the omentum after completion to seal the incision and provide blood supply and lymphatic drainage.

Technique

Fig. 1: The jejunal artery and vein are ligated
Expose the affected bowel and pack it off with moistened laparotomy sponges. Ligate the jejunal artery and vein supplying the intestine to be removed and also ligate the small vasa recti branches immediately adjacent to the mesenteric aspect of the intestine.(Figs. 1-2) 
Fig. 2: The vasa recti vessels have been ligated and the bowel is grasped with fingers
Divide the mesentery between jejunal vessel ligatures. Have the assistant place fingers on each side of the proposed incisions in the intestine to prevent leakage.

Place clamps on the bowel to be removed to prevent spillage of contents. Incise the bowel with a scalpel on each side of the segment to be removed. Angle the cuts away from the segment to insure good blood supply to the anti-mesenteric aspect of the intestine.(Fig. 3)
Use suction to gently remove material from the bowel lumen.  
Fig. 3: Lines indicate the angle of incisions to resect the indicated portion of intestine
Appose the two ends of the intestine and begin two sutures lines, one at the mesenteric aspect and one at the anti-mesenteric aspect.(Fig. 4) 
Fig. 4: Two lines of suture are placed in the ends of the intestine
Sutures are placed full thickness from serosa to mucosa on one side and mucosa to serosa on the other side. Place mosquito forceps on the free end of each suture after they are tied. The weight of these forceps helps to stabilize and align the anastomosis. Run one suture from top to bottom in a simple continuous pattern.1 (Fig. 5) 
Fig. 5: Suture from top to bottom simple continuous
Have the assistant maintain traction on the suture to prevent loosening, and use the suture needle to guide each loop of suture into place. At the end of the suture line, tie to the free end of the other suture.  Flip the bowel over and repeat on the other side. (Fig. 6)
Fig. 6: Flip the intestine over and suture the opposite side
Leak test the anastomosis by injecting 10-12cc of sterile saline into the anastomosis and gently massaging the fluid back and forth through the anastomosis. Place simple interrupted sutures as needed in leaking areas.

Wrap the anastomosis with the greater omentum by pulling it through the mesenteric opening and draping it around the intestine. Suture the omentum to itself and to the serosa of the bowel on the anti-mesenteric area. (Fig. 7-8) 
Fig. 7: Place the greater omentum through the mesenteric rent

Fig. 8: Wrap the omentum around the anastomosis and suture to itself and to the serosa of the intestine

References

1. Weisman DL, Smeak DD, Birchard SJ, Zweigart SL. Comparison of a continuous suture pattern with a simple interrupted pattern for enteric closure in dogs and cats: 83 cases (1991-1997). J Am Vet Med Assoc. 1999 May 15;214(10):1507-10.