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Afferent Loop Syndrome

What is afferent loop syndrome?

Afferent loop syndrome is a complication of several different types of stomach surgery. If you have had or are going to have a procedure called gastrojejunostomy, you should know that afferent loop syndrome can occur after the surgery. Gastrojejunostomy is also also known as Billroth II gastrectomy procedure,.

During a Biliroth II type of operation, your surgeon will remove or bypass the lower part of your stomach and attach the remaining part of your stomach to a loop of intestine downstream. The area where your stomach and intestine attach is called the anastomosis. The intestine downstream from the anastomosis is called the efferent limb.

What causes afferent loop syndrome?

After surgery, your bile and pancreatic digestive juices enter the afferent loop. All these juices flow downstream and need to pass through the anastomosis and enter your digestive system. Afferent loop syndrome occurs when something traps the flow of these juices up to and past the anastomosis.

Following are common causes of afferent loop syndrome:

  • An improperly made anastomosis
  • Twisting or kinking of the afferent loop
  • Trapping of the afferent loop secondary to scar tissue in an area near the surgery
  • Scarring from ulceration at the site where the afferent loop joins the stomach
  • Cancer that recurs and blocks the afferent loop

What are the symptoms of afferent loop syndrome?

Symptoms will start to appear when the secretions from your pancreas and bile fill the afferent loop and are unable to pass through the anastomosis. The secretions build up in the afferent limb. This causes pressure, especially after a meal. Afferent loop syndrome can occur anywhere from days to years after surgery. Afferent loop syndrome that occurs soon after surgery—within the first few weeks—is called acute afferent loop syndrome. This usually means the afferent loop is completely obstructed. Afferent loop syndrome that occurs weeks, or even years, after surgery is called chronic afferent loop syndrome. This usually means there is a partial obstruction.

The most common symptoms are:

  • Abdominal pain, especially in the upper right side of your abdomen
  • Nausea and fullness, especially after eating
  • Sudden and severe vomiting of bilious fluid. This occurs when the obstruction of the distended afferent loop is relieved and the afferent loop decompresses its content into the stomach. This relieves the abdominal pain

How is afferent loop syndrome diagnosed?

Your health care provider may suspect afferent loop syndrome if you have symptoms any time after gastrojejunostomy surgery. Although blood tests and basic X-rays can help with the diagnosis, the best test is a CT scan. This will show the fluid-filled, swollen afferent loop. Another test you may get is an upper GI endoscopy. This will show obstruction of the afferent limb.

How is afferent loop syndrome treated?

Treatment is almost always surgery. In acute afferent loop syndrome, emergency surgery may be necessary to prevent rupture of the loop. The type of surgery will depend on what's causing the actual obstruction. In some cases, the anastomosis may need to be taken apart and redone. If the afferent loop has become scarred and narrowed, it may need to be removed.

When should I call my health care provider?

To better understand the complications of gastrectomy surgery, ask your doctor to explain all the risks and benefits of the surgery before your procedure. After surgery, carefully follow your medical team's instructions. And always call your doctor right away if you have any symptoms that could indicate afferent loop syndrome. 

Key points

  • Afferent loop syndrome is a complication of several different types of stomach surgery. Afferent loop syndrome occurs when something traps the flow of your  digestive juices up to and past the anastomosis.
  • Symptoms will start to appear when the secretions from the pancreas and bile fill the afferent loop and are unable to pass through the anastomosis causing pressure.
  • Common symptoms are:
    • Abdominal pain
    • Nausea and fullness
    • Sudden and severe vomiting of bilious fluid
  • Afferent loop syndrome can occur anywhere from days to years after surgery
  • The best test for diagnosis is a CT scan
  • Treatment is almost always surgery.
  • Call your health care provider right away if you have any symptoms that could indicate afferent loop syndrome. 

 

Next steps

Tips to help you get the most from a visit to your health care provider:

  • Before your visit, write down questions you want answered.
  • Bring someone with you to help you ask questions and remember what your provider tells you.
  • At the visit, write down the names of new medicines, treatments, or tests, and any new instructions your provider gives you.
  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your provider if you have questions.

Medical Reviewers:

  • Berry, Judith, PhD, APRN
  • Fetterman, Anne, RN, BSN