Anastomosis: Definition, Advantages, Risks, Limitations, Types and Differences

It is the connection of normally separate parts.

An anastomosis can occur naturally or it can be created during embryonic development , surgery or trauma, or by pathological means.

An anastomosis can, for example, connect two blood vessels, or it can connect healthy sections of the colon or rectum after a cancerous or otherwise diseased portion has been surgically removed.

Surgical anastomosis is a procedure performed to join two previously distant structures in the human anatomy.

Anastomosis is a connection that occurs between two structures in the body.

These structures are generally hollow or tubular in shape, like blood vessels or bowel loops.

In the anastomosis, the space between the organs is stitched or stapled.

Advantages of the Anastomosis

The advantages of the anastomosis are:

  • It establishes a connection between two parts that otherwise branch or diverge.
  • An anastomosis connecting an artery and a vein also creates an arteriovenous fistula as an access for hemodialysis.


As with any surgery, the anastomosis carries some risks.

The risks associated with this procedure are:

  • Chest infections can occur in smokers who have undergone blood vessel anastomosis.
  • Under the bowel repair procedure, it may take a while for your bowel movement to restore to normal.
  • The patient may also notice discharge from the surgical wound and a clear patch around it.
  • There is also a probability of wound infection.
  • Bleeding and blood clots.
  • Blocking.
  • Stenosis or abnormal narrowing.
  • Damage to surrounding structures.
  • Infections, which can lead to sepsis .
  • Anastomotic leaks or leaks at the site where the intestine is reconnected.


The limitations of the procedure are:

  • Reaction to a foreign body.
  • Ulcer development.

Types of anastomosis

The first type of anastomosis is the naturally occurring anastomosis.

This means that different structures are automatically connected by the normal arrangement of the body.

If we look at the circulatory system, we see many examples of veins and arteries that are naturally connected to each other.

Different blood vessels are naturally connected in an example of an anastomosis.

This helps the body function by transporting blood and nutrients to all the cells, tissues, and organs that need it.

The second type of anastomosis is a connection formed by surgical intervention such as:

  • A surgical connection of the blood vessels.
  • An arteriovenous fistula for dialysis.
  • A transplant.
  • Between a graft and a blood vessel to create a bypass.
  • In parts of the gastrointestinal tract by blockage (resection).
  • In a colostomy.
  • In the urinary tract.

In the case of blood vessels, the blocked part is often not removed.

An example of a natural conduit would be the use of the saphenous vein to bypass blocked arteries in the heart.

An example of an artificial conduit would be using a Dacron tube to bypass arteries in the leg.

In these cases, the anastomosis refers to where the two structures are sutured together.

Many people with gastrointestinal disorders, such as Crohn’s disease or colorectal cancer, may need a surgical anastomosis to help treat the complications of their conditions.

Anastomosis ileocólica

An ileocolic or ileocolonic anastomosis is the attachment of the end of the ileum, or small intestine, to the first part of the large intestine, called the colon.

It is usually done after bowel resection in people with Crohn’s disease.

This is because the disease often affects the small intestine and the first part of the large intestine.

An ileocolic anastomosis is usually performed to rejoin the intestines after a bowel resection.

A bowel resection is the removal of a damaged portion of the intestine.

People with the following conditions may need a bowel resection:

  • Colonrectal cancer.
  • Crohn’s disease .
  • Ulcerative colitis
  • Enteritis.
  • Intestinal abscess.
  • Meckel’s diverticulum, an abnormal sac in the intestine present at birth.
  • Severe intestinal ulcers
  • Blockage in the intestines.
  • Precancerous polyps
  • Trauma, like a wound.

In most cases, the anastomosis can be performed laparoscopically.

Laparoscopy means that the surgery is done through a small incision with a small instrument called a laparoscope.

Other types of intestinal anastomoses may be performed during the following medical procedures:

Gastric band surgery

Gastric bypass surgery is a type of bariatric surgery that is usually done to help a person lose weight.

Two anastomoses are performed during gastric bypass surgery.

First, the upper part of the stomach becomes a small gastric pouch.

A portion of the small intestine is cut and then connected to this new gastric pouch. This is the first anastomosis.

The other end of the small intestine is reconnected to the small intestine lower down. This is the second anastomosis.

Removal of a tumor

An example would be a pancreatic tumor. After the tumor is removed, the organs will need to be reattached.

This can include the bile ducts, pancreas, gallbladder, and part of the stomach.

Vascular and circulatory anastomoses

Circulatory and vascular anastomoses occur naturally in the body. For example, your body can create a new path for blood to flow if one path is blocked.

Naturally occurring circulatory anastomoses are also important for regulating body temperature.

Vascular anastomosis can also be performed surgically. It is often used to repair injured or damaged arteries and veins.

Conditions and procedures that may require vascular anastomosis include:

  • Damage to an artery due to injury.
  • Coronary artery bypass surgery to treat a blockage of an artery supplying the heart due to atherosclerosis.
  • Solid organ transplant to connect the new organ to the blood supply.
  • Hemodialysis.

During coronary bypass surgery, for example, a surgeon will use blood vessels taken from another area of ​​your body to repair a damaged or blocked artery.

Your surgeon will remove a healthy blood vessel from inside the wall or leg of your chest.

One end of the blood vessel joins above the blockage and the other below.

In contrast to the intestines and stomach, vascular anastomoses are always sewn up by the surgeon and never stapled.

Anastomosis versus colostomía

After a bowel resection, a doctor must address the two open ends of the bowel.

They may recommend a colostomy or anastomosis. It depends on the amount of intestine that was removed. Here the differences between the two:

  • In the anastomosis, the surgeon will reattach the two ends of the intestine together with stitches or staples.
  • In a colostomy, the surgeon will place one end of the intestine through an opening in the abdominal wall and connect it to a dispenser or bag.

This is done so that the stool that would normally move through the intestine into the rectum passes through the opening in the abdomen into the pouch. The bag must be emptied manually.

A colostomy is often only used as a short-term solution. It allows other parts of your intestine to rest while you recover from another surgery.

Once recovered, an anastomosis is performed to rejoin the two ends of the intestine.

Sometimes, not enough healthy intestine remains to perform an anastomosis.

In this case, a colostomy is a permanent solution.

Recognizing and treating a leak

An anastomotic leak is a rare but serious complication of the anastomosis.

As the name suggests, an anastomotic leak occurs when the newly created connection fails to heal and begins to leak.

Signs of an anastomotic leak after anastomosis may include:

  • Fever.
  • Abdominal pain.
  • Low urine output
  • Ileus , or lack of movement in the intestine.
  • Diarrhea .
  • Higher than normal white blood cell count.
  • Peritonitis.

The risk of leakage is higher in obese people.

Smoking and heavy drinking can also increase the risk of an anastomotic leak.

If the leak is small, it can be treated with antibiotics or with a drain placed through the abdominal wall until the intestines heal. If the leak is larger, another surgery is required.

In some cases, a colostomy will be required along with an abdominal wash.

During a wash, a salt water solution is used to wash the peritoneal cavity, including the intestines, stomach, and liver.