Afferent loop syndrome is a problem that can occur after some kinds of stomach surgery. It’s also known as afferent limb syndrome.
The small intestine loop has 2 loops. The loop going to the upper stomach is the afferent loop. The loop carrying food away from the stomach is called the efferent loop. Afferent loop syndrome can occur after some types of gastrojejunostomy. One type is the Billroth II gastrectomy. During the procedure, a surgeon will remove or bypass the lower part of the stomach and attach the remaining upper part of the stomach to a loop of small intestine. The new connection is the anastomosis.
After surgery, your bile and digestive fluids enter the afferent loop. The fluids flow toward the upper stomach. They need to pass through the anastomosis and then enter the efferent loop to help digest your food. Afferent loop syndrome occurs when something traps the flow of these juices in the afferent loop. Fluid pressure builds up in the afferent loop and causes discomfort and nausea. If the pressure builds up, the bile and pancreatic fluid may then empty into the upper stomach. This can cause symptoms such as vomiting.
Common causes of afferent loop syndrome include:
A problem with an anastomosis after gastrojejunostomy, such as an ulcer
Twisting of the afferent loop
Scar tissue (adhesions) near the afferent loop after surgery
Cancer that blocks the afferent loop
Foreign bodies such as a mass
Afferent loop syndrome can occur anywhere from days to years after surgery. If it occurs soon after surgery, it’s called acute afferent loop syndrome. If it occurs weeks or years after surgery, it’s called chronic afferent loop syndrome.
The most common symptoms are:
Abdominal pain, especially in the upper right side of your abdomen
Nausea and fullness, especially after eating
Sudden, severe vomiting of fluid with bile in it that suddenly eases the pain
Your healthcare provider may diagnose afferent loop syndrome based on your symptoms after surgery. You may have a CT scan. This may show the swollen afferent loop. You may also have an upper endoscopy. This can show blockage of the afferent loop.
Treatment is almost always surgery. For acute afferent loop syndrome, emergency surgery may be needed. This is to prevent a tear of the loop. The type of surgery will depend on what's causing the blockage. In some cases, the anastomosis may need to be redone. Scar tissue may need to be removed.
Call your healthcare provider right away if you have symptoms of afferent loop syndrome.
It occurs when something traps the flow of digestive juices in the afferent loop. Fluid pressure builds up in the loop and causes discomfort and nausea.
Common symptoms are abdominal pain, nausea, and sudden vomiting of fluid with bile in it.
Treatment is almost always surgery. For acute afferent loop syndrome, you may need emergency surgery.
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