What are the other Names for this Condition? (Also known as/Synonyms)

• Pancreas with Annular Morphology

What is Annular Pancreas? (Definition/Background Information)

• Annular Pancreas is a rare congenital developmental anomaly, in which the portion of the pancreas called the head, is abnormal in anatomy
• In Annular Pancreas, the head of pancreas has a ring-like tissue, which surrounds a portion of the small intestine (called the second part of duodenum)
• Due to the abnormal surrounding of the pancreatic tissue around the duodenum, it may cause a blockage of the blood supply, which may result in its abnormal functioning
• Blockage in the lumen (inner cavity/tubular space) of duodenum can also occur easily, if pancreatic tissue develops inflammation, known as pancreatitis

Who gets Annular Pancreas? (Age and Sex Distribution)

• Annular Pancreas mostly occurs as an abnormal development, during the fetal growth stage. The estimated incidence worldwide is 1 in 12,000-15,000 newborns
• Both male and female sexes are prone to develop Annular Pancreas; but, the incidence is higher in males, than compared to females. No ethnic or racial preference is noted
• Occasionally, even adults, may develop such a condition

What are the Risk Factors for Annular Pancreas? (Predisposing Factors)

Following are risk factors for Annular Pancreas:

• Individuals with Down syndrome have an increased risk
• The presence of tracheoesophageal fistula increases the risk. A tracheoesophageal fistula is an abnormal connection between the esophagus (food pipe) and the trachea (wind pipe)
• Intestinal atresia: Blockage of the intestine, due to an abnormal formation of the lumen
• Acute and chronic pancreatitis
• Presence of co-existing congenital abnormalities in the abdomen

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Annular Pancreas? (Etiology)

• Annular Pancreas is caused by an abnormal development of the pancreas. The exact reason behind this abnormal development of pancreas is unknown
• During the developmental process, the head of the pancreas develops atypically, due to an abnormal fusion of the pancreatic buds. This takes place due to an improper rotation of the ventral buds of the developing pancreas, within the fetus
• Ventral buds are responsible for forming the head portion of the pancreas. The dorsal buds are responsible for formation of the body and tail of the pancreas

What are the Signs and Symptoms of Annular Pancreas?

The signs and symptoms due to Annular Pancreas can manifest in a newborn, or be observed during adulthood. They include the following, observed during or after childbirth:

• Low birth weight
• Difficulty in feeding, right from birth, resulting in nausea and vomiting
• Polyhydramnios (increased amount of amniotic fluid) during pregnancy, seen in the mother

Not all Annular Pancreas cause abnormal signs and symptoms; in many cases, no symptoms are seen.

How is Annular Pancreas Diagnosed?

A diagnosis of Annular Pancreas would involve:

• X-ray study of the abdomen: This may show the classical “double-bubble” sign
• Ultrasound, CT scan of abdomen
• Contrast studies of small intestines, using barium
• An ERCP (endoscopic retrograde cholangiopancreatography) may be performed. This can help track through imaging, the accessory pancreatic duct

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Annular Pancreas?

Complications due to Annular Pancreas include:

• Without treatment, there could be an obstruction of the duodenum, which might lead to a series of complications including vomiting, indigestion, peptic ulcer, and in severe cases perforation of the bowel wall
• Blockage of blood supply could result in necrosis (ischemic necrosis) of the bowel wall, which in turn can cause perforation of bowel wall and abdominal infection (bacterial peritonitis)
• Obstruction of the bile duct can result in jaundice (obstructive jaundice). This can also cause pancreatic inflammation (or pancreatitis). In such cases, the possibility of cancer of the pancreas should be ruled out using additional studies, such as a biopsy
• There is an increased incidence of pancreatic cancer, in individuals with Annular Pancreas. The cause for this increase remains unknown

How is Annular Pancreas Treated?

If individuals do not have any symptoms, then no treatment is generally required. Surgical treatment is the treatment of choice, in those who exhibit signs and symptoms due to Annular Pancreas.

• Surgical options include duodeno-duodenostomy and laparoscopic gastrojejunostomy. Both these surgical procedures are used in bypassing the blocked duodenum
• Current medical literature informs that a surgical removal of the Annular Pancreas should not be performed. This can result in severe complications from an injured pancreas, such as pancreatic fistula formation and acute pancreatitis

How can Annular Pancreas be Prevented?

Annular Pancreas is a congenital developmental abnormality. Currently, there are no methods available to prevent it.

What is the Prognosis of Annular Pancreas? (Outcomes/Resolutions)

• If symptoms due to Annular Pancreas are noticed during the infancy stage, then the prognosis is guarded. Typically, in such cases, other congenital abnormalities are present in the infant, together with Annular Pancreas, thus increasing its mortality
• If the symptoms occur during adulthood, then with prompt and appropriate treatment, the prognosis is usually excellent

Additional and Relevant Useful Information for Annular Pancreas:

The following DoveMed website link is a useful resource for additional information:

https://www.dovemed.com/healthy-living/digestive-center/