Duodenal Atresia

Duodenal atresia is a congenital condition characterised by the absence or closure of a portion of the duodenum, which is the initial segment of the small intestine immediately beyond the stomach. This obstruction impedes the normal flow of stomach contents into the intestines, leading to a range of complications.

Causes of Duodenal Atresia

Duodenal atresia is primarily a congenital anomaly, meaning it is present at birth. The exact aetiology remains unclear, but it is believed to result from an interruption in the normal development of the duodenum during fetal growth. Various factors, including genetic mutations and environmental influences, may contribute to the occurrence of duodenal atresia.

Genetic Factors

Research indicates a significant correlation between duodenal atresia and certain genetic disorders. Notably, it is frequently associated with Down syndrome, also known as trisomy 21. Approximately one-third of infants with duodenal atresia also have Down syndrome. Other chromosomal abnormalities, such as Edwards syndrome (trisomy 18), may also be linked to this condition.

Environmental Factors

While genetic factors play a crucial role, environmental influences cannot be disregarded. Maternal smoking, alcohol consumption, and exposure to certain medications during pregnancy have been suggested as potential risk factors. However, the precise mechanisms through which these factors contribute to duodenal atresia are not well understood and require further investigation.

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Symptoms of Duodenal Atresia

The symptoms of duodenal atresia typically manifest shortly after birth, often within the first 24 to 48 hours. The hallmark symptom is bilious vomiting, which is the expulsion of greenish-yellow bile-stained vomit. This occurs because the obstruction prevents the passage of bile from the liver into the intestine. Other notable symptoms include:

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Diagnosis of Duodenal Atresia

The diagnosis of duodenal atresia typically involves a combination of prenatal and postnatal evaluations. Early detection is crucial for timely intervention and improved outcomes.

Prenatal Diagnosis

Advancements in prenatal imaging techniques, such as ultrasound and fetal MRI, have enabled the early identification of duodenal atresia. Polyhydramnios, an excessive accumulation of amniotic fluid, is a standard prenatal indicator of gastrointestinal obstruction, including duodenal atresia. The "double bubble" sign, characterised by the presence of two fluid-filled structures (the stomach and the proximal duodenum) on ultrasound, is highly suggestive of duodenal atresia.

Postnatal Diagnosis

After birth, a combination of clinical evaluation and imaging studies is used to confirm the diagnosis. An abdominal X-ray is often performed to visualise the characteristic "double bubble" sign. In some cases, an upper gastrointestinal series or contrast study may be conducted to further delineate the obstruction and rule out other potential causes.

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Complications of Duodenal Atresia

Duodenal atresia can lead to several complications if left untreated. Timely surgical intervention is essential to prevent these adverse outcomes.

Nutritional Deficiencies

The obstruction impairs the normal digestion and absorption of nutrients, leading to malnutrition and growth retardation. Infants with duodenal atresia may require specialised nutritional support, including intravenous fluids and parenteral nutrition, until the obstruction is surgically corrected.

Biliary Complications

The accumulation of bile in the stomach and duodenum can result in bile reflux and subsequent damage to the gastric and duodenal mucosa. This can lead to inflammation, ulceration, and an increased risk of infection.

Respiratory Complications

Severe abdominal distension due to the accumulation of stomach contents can exert pressure on the diaphragm, compromising respiratory function. This can result in respiratory distress and an increased risk of aspiration pneumonia.

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Treatment of Duodenal Atresia

The definitive treatment for duodenal atresia is surgical intervention. The goal of surgery is to bypass or remove the obstructed segment of the duodenum and restore regular gastrointestinal continuity.

Preoperative Management

Before surgery, infants with duodenal atresia require stabilisation to address dehydration, electrolyte imbalances, and nutritional deficiencies. This typically involves the administration of intravenous fluids, electrolyte replacement, and parenteral nutrition. Nasogastric decompression may be performed to relieve abdominal distension and reduce the risk of aspiration.

Surgical Approaches

Several surgical techniques can be employed to correct duodenal atresia, depending on the specific anatomy and location of the obstruction. The most common procedures include:

Postoperative Care

Following surgery, infants require close monitoring and supportive care to ensure a smooth recovery. This includes pain management, nutritional support, and gradual reintroduction of oral feeds. Regular follow-up visits are essential to monitor growth and development and to address any potential complications.

Prognosis and Long-term Outcomes

With timely surgical intervention, the prognosis for infants with duodenal atresia is generally favourable. Most infants achieve average growth and development following surgery. However, long-term follow-up is necessary to monitor for potential complications, such as:

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Conclusion

Duodenal atresia is a complex congenital condition that requires prompt diagnosis and surgical intervention. Understanding the causes, symptoms, and treatment options is crucial for healthcare providers and parents alike. With advances in prenatal diagnosis and surgical techniques, the outlook for infants with duodenal atresia continues to improve, offering hope for a healthy and fulfilling life.