What is Duodenal Atresia and Stenosis?
Duodenal atresia is a condition a baby is born with, in which their small intestine is blocked. This condition can lead to vomiting, which may have a yellow-green color, or not, within the first 24 to 38 hours of the baby’s life, generally after they have their first meal. This blockage is often connected to a condition during pregnancy when there’s too much amniotic fluid – a condition called polyhydramnios, and it’s one of the most frequent reasons for a blockage in the unborn baby’s bowel.
The diagnosis of this condition can be made during pregnancy using an ultrasound. If the diagnosis is not made during pregnancy, the condition can be detected after birth, initially by taking a simple abdominal x-ray. If needed, other tests like a restricted upper gastrointestinal (UGI) series using a special liquid called barium, or an ultrasound evaluation using water or Pedialyte, can also be used to confirm the diagnosis. CT scans, on the other hand, are not particularly useful in diagnosing duodenal atresia.
What Causes Duodenal Atresia and Stenosis?
Duodenal atresia is a condition that happens when the duodenum, the first part of the small intestine, gets blocked. This usually happens beyond an area called the ampulla of Vater in the second part of the duodenum. This blockage generally occurs as a result of mistakes during the eighth to the tenth week of a baby’s development in the womb.
In this condition, the duodenum is completely blocked. When the duodenum is narrowed but not fully blocked, we call it duodenal stenosis. Another cause of duodenal blockage could be a duodenal web. This is less common and causes a “windsock” shape in the duodenum.
Risk Factors and Frequency for Duodenal Atresia and Stenosis
Duodenal atresia is a condition that happens in 1 out of every 5,000 to 10,000 live births. This condition can often be found alongside other health issues such as Down syndrome and heart defects. For example, 30 to 40 percent of kids with duodenal atresia also have Down syndrome. Down syndrome patients have a 3 percent chance of also having congenital duodenal atresia. The condition affects males and females equally. Furthermore, there can often be a connection between duodenal atresia and other health conditions such as VACTERL, annular pancreas, and other bowel atresias including jejunal atresia, ileal atresia, and rectal atresia.
Signs and Symptoms of Duodenal Atresia and Stenosis
Duodenal atresia is a condition that shows up early in a baby’s life, usually within the first 24 to 38 hours after their first meal. This condition can cause a baby to vomit, which can get worse if it’s not taken care of right away. Sometimes, this vomiting can be forceful like in conditions such as pylorospasm (a spasming of the opening from the stomach into the small intestine) and gastroesophageal reflux (a backup of stomach acid into the esophagus). However, these conditions can mimic a different problem known as hypertrophic pyloric stenosis.
If a baby is vomiting up bile (a greenish-yellow substance), this might mean they have a blockage in their intestines that’s located after the ampulla of Vater (a small opening where the pancreatic and bile ducts enter the small intestine). However, some babies with atresia (blockage) that’s before the ampulla of Vater might not vomit up bile. Too much bile in the vomit can lead to low potassium and chloride levels in the body, along with a higher pH level than normal (a condition known as hypokalemic hypochloremic metabolic alkalosis), especially if the baby isn’t getting enough fluids. This can be confusing because the urine might be acidic despite the higher body pH. The babies also might have belly swelling and might not be able to pass stool.
Testing for Duodenal Atresia and Stenosis
Antenatal imaging is a type of testing done before a baby is born. This testing can highlight a condition known as duodenal atresia. The ‘double bubble’ sign can be seen in these tests – it’s a particular pattern that indicates a blockage in the baby’s digestive system. This blockage is between the stomach, which is filled with the baby’s amniotic fluid, and a part of the small intestine called the duodenum.
The ‘double bubble’ can be observed when performing an ultrasound during pregnancy, leading to an early diagnosis of duodenal atresia. You can picture this ‘double bubble’ as two close bubble-like structures in the baby’s belly on sonograms. However, the sonographer needs to ensure a connection between the two ‘bubbles’ as other conditions like foregut duplication cyst can imitate the ‘double bubble’ pattern.
After the baby is born, a simple abdominal x-ray can help confirm the diagnosis. This x-ray may reveal gas-filled spaces in the stomach and the start of the small intestine (duodenum), but not in the lower parts. The x-ray can show two air-filled sacs, one being the stomach and the smaller one being the duodenum – this is the ‘double bubble’ sign again. The condition may be caused by other problems, like the annular pancreas, or obstructions in other parts of the baby’s belly. Besides, babies with Down syndrome have a higher chance of having duodenal atresia.
When duodenal atresia is suspected but not yet confirmed before the baby is born, the doctors might use barium fluoroscopy. It’s a kind of x-ray where the baby’s gastrointestinal tract is examined using a certain kind of solution. If necessary, additional ultrasound tests or upper gastrointestinal series (UGI), a type of x-ray procedure, can also be performed.
Sometimes doctors may use a contrast agent called barium to get a clearer view during the ultrasound. This practice is typically done with great care to prevent complications, like the baby breathing in (aspiring) the substance.
A CT scan might be used, but rarely, for diagnosing duodenal atresia as it requires complex preparation and comes with additional concerns like radiation exposure. This method might be useful for confusing cases to help understand the layout of the intestines.
In the end, if the ‘double bubble’ sign is seen, the doctors would promptly arrange a talk with a surgeon to discuss the next step in managing the baby’s condition.
Treatment Options for Duodenal Atresia and Stenosis
The treatment for certain digestive system issues often involves surgery, which typically requires a two-step process.
Firstly, a procedure known as nasogastric suction is performed. This involves inserting a small, flexible tube through the nose and into the stomach to remove excess air and fluids, which can relieve pressure.
After this, surgery is performed to fix the health issue that’s causing the blockage. Most commonly, a procedure called a duodenoduodenostomy is carried out. This operation can either be done as an open surgery (with a large incision) or laparoscopically (with small incisions and special instruments). However, carrying out this operation laparoscopically can be technically demanding.
During a duodenoduodenostomy, surgeons create a bypass or shortcut in the digestive tract to avoid passing by the obstruction. The new path is made to mimic a diamond-shape and safely bypasses important parts of the stomach and pancreas.
Before the surgery, the stomach and part of the small intestine (duodenum) are usually emptied using an orogastric tube (a tube similar to the nasogastric one but placed through the mouth instead of the nose) and fluid levels in the body are managed with intravenous fluids, which are delivered directly into the blood vessels.
As with any surgery, duodenoduodenostomy has its risks; it may lead to acid reflux, an enlarged duodenum, and impaired movement of the duodenum. To avoid other complications, a thorough surgery evaluation is done to check for any other possible blockages in the intestine.
What else can Duodenal Atresia and Stenosis be?
When a newborn baby is throwing up bile, it can indicate certain health issues. Medical professionals would usually consider:
- Duodenal atresia, a birth defect where the first part of the small bowel (the duodenum) is not formed properly
- Duodenal stenosis, a narrowing of the same region
- Annular pancreas, when the pancreas forms a ring around the small bowel
- Most importantly, malrotation of the intestine, where the intestines twist around and block off blood flow to the lower bowel. This condition, called midgut volvulus, usually comes on a few days later than duodenal atresia
It’s crucial to also check for other gut-related deformities that often accompany Down syndrome, like:
- Anal atresia, which is a blockage or absence of the anal opening
- Hirschsprung’s disease, a condition causing bowel obstruction
- Diaphragmatic hernia, where there’s a hole in the diaphragm
- Omphalocele, a birth defect where some of the baby’s organs stick out from the belly button
What to expect with Duodenal Atresia and Stenosis
The outlook after successful surgery for duodenal atresia, which is a blockage in the first part of the small intestine, is generally very good. According to a study that observed infants from 1972 to 2001, about 12% of them experienced complications later on, and 6% unfortunately passed away. Even so, most patients recover well after this surgery.
Possible Complications When Diagnosed with Duodenal Atresia and Stenosis
Possible complications linked to surgery can include:
- Megaduodenum: This is a condition where the first part of the small intestine (called the duodenum) becomes larger than normal.
- Blind loop syndrome: This condition happens when a portion of the intestine forms a loop that food bypasses during digestion.
- Cholecystitis: An inflammation of the gallbladder.
- Esophagitis: A condition that involves inflammation in the esophagus, which is the tube that connects the throat to the stomach.
- Peptic ulcer disease: This refers to painful sores or ulcers in the lining of the stomach or the first part of the small intestine (the duodenum).
- GERD: Also known as Gastroesophageal Reflux Disease, it’s a digestive disorder occurring when stomach acid frequently flows back into the tube connecting your mouth and stomach (oesophagus).
- Pancreatitis: An inflammation of the pancreas.
- Anastomotic leak: A complication that can occur after surgery where there’s a breakdown that causes fluid to leak from the surgical connection between two pieces of intestine.
Recovery from Duodenal Atresia and Stenosis
After surgery, patients often need a nasogastric tube, a tube inserted through the nose into the stomach, to continue draining fluids. This might also need to be paired with parenteral nutrition, which is a way of delivering nutrients directly into the bloodstream. When the output from the nasogastric tube significantly decreases or stops, food can be introduced slowly and increased as the patient is able to tolerate more.
The decision of when to start feeding the patient through the digestive system, or enteral feeding, depends on the patient’s specific situation. If there’s any worry about the healing of the surgical connections within the digestive tract, such as the connection between the stomach and the first part of the small intestine or the connection between the stomach and the second part of the small intestine, a special kind of X-ray using a safe, water-soluble contrast dye might be performed.
Preventing Duodenal Atresia and Stenosis
No one can prevent duodenal atresia, a condition that develops before birth, from happening. It’s important for parents to understand that this issue is linked to problems that occur during the baby’s development in the womb. It’s equally crucial for them to know that they didn’t cause their baby’s condition. It’s not due to anything they did or didn’t do before or during the pregnancy.
