What Are the Three Types of Anastomosis?

An intestinal anastomosis is the opening between two parts of the gastrointestinal tract. Surgeons must sometimes remove diseased parts and reconnect the healthy parts with an opening for food to pass through.

An anastomosis is a medical term used to describe connection or opening between two organs or tissues. When a part of the small or large intestine is surgically removed due to a disease or condition, the two sections of the remaining part of the intestine are joined together (intestinal anastomosis) to re-establish the continuity of the intestine. 

The intestinal anastomosis is performed following the surgical removal of part of the intestine due to intestinal diseases ore cancers. Removal of parts of the intestine may be necessary for the following conditions:

• Intestinal gangrene (tissue death due to loss of blood supply) 
• Malignancy (cancer)
• Benign tumors (e.g., intestinal polyps, intussusception, worm infestations with intestinal obstruction)
• Infections tuberculosis complicated with stricture or perforation)
• Perforations due to infection, ulcers or trauma 
• Damage to the intestine due to radiation therapy. 
• Complications with bleeding, stricture or perforation
• Inflammatory bowel disease, ulcerative colitis or Crohn disease
• Scarring and adhesions causing the intestinal block
• Chronic constipation
• Birth defects of the intestine (e.g. Meckel’s diverticulum, cysts, Hirschsprung disease)

Intestinal resection and anastomosis are performed during the same procedure. The procedure may be done in adults and children.

The intestinal anastomosis may not be feasible in conditions with a high risk of anastomotic leakage. In such cases, the surgeon may advise alternative techniques. 

The intestinal anastomosis is avoided in patients with the following conditions:

• Severe sepsis (widespread infection)
• Poor nutritional status 
• Cancer metastasis (widespread cancer cells)
• Questionable viability of the intestine
• Fecal contamination or infection in the abdomen
• Unhealthy and diseased intestine

The intestinal anastomosis is performed under anesthesia. After removal of the part of the small or large intestine, the remaining two sections are anastomosed using sutures or surgical staples. 

The surgeon decides on which surgical technique to perform the intestinal anastomosis based on the patient and the condition. The three types of intestinal anastomosis are::

• Side-to-side anastomosis: In this technique, the sides of each part of the bowel are either sutured or stapled rather than the two ends. 
• End-to-end anastomosis: In this technique, the two open ends of the intestines are connected.
• End-to-side anastomosis: In this technique, the end of the intestine which is smaller is connected to the side of the larger section.

Like any major surgery, there is a risk of complications during and after the anastomosis surgery. Some common complications are:

• Bleeding
• Reaction to anesthesia 
• Localized blood clot and smaller blood clots which enter the blood vessels causing heart and lung complications.
• Damage to surrounding structures
• Infection
• Scarring and adhesions, causing intestinal narrowing and/or blockage
• Wound dehiscence (a condition where the cut made during a surgical procedure separates or ruptures after being stitched together)
• Anastomotic leak (intestinal contents may leak through the site of anastomosis) which may lead to systemic infection
• Altered bowel movements