Overview
Definition:
Duodenal atresia is a congenital anomaly characterized by a complete obstruction of the duodenal lumen, preventing the passage of intestinal contents
It is the second most common cause of intestinal obstruction in neonates, after malrotation with volvulus.
Epidemiology:
The incidence of duodenal atresia is estimated to be 1 in 5,000 to 10,000 live births
It is frequently associated with other congenital anomalies, most notably Down syndrome (trisomy 21), occurring in 20-40% of affected infants
Annular pancreas and intestinal malrotation are also common comorbidities.
Clinical Significance:
Early recognition and prompt surgical intervention are critical for survival
Delay in diagnosis can lead to severe dehydration, electrolyte imbalance, aspiration pneumonia, and potentially death
Understanding the "double-bubble" sign on imaging is essential for diagnosis.
Clinical Presentation
Symptoms:
Non-bilious vomiting shortly after birth, often described as projectile
Abdominal distension, typically prominent above the umbilicus
Failure to pass meconium within the first 24-48 hours of life
Poor feeding and failure to thrive
Jaundice may be present due to associated anomalies or prolonged feeding intolerance.
Signs:
Abdominal distension, more pronounced in the upper abdomen
Visible gastric peristalsis may be noted in thin infants
Palpable mass in the epigastrium is rare
Bowel sounds may be normal or hyperactive initially, becoming hypoactive with progression of obstruction
Signs of dehydration may be present.
Diagnostic Criteria:
Clinical suspicion based on persistent non-bilious vomiting in a neonate
Confirmation typically relies on plain abdominal radiography and upper gastrointestinal contrast studies
The presence of the characteristic "double-bubble" sign is diagnostic.
Diagnostic Approach
History Taking:
Detailed history of the pregnancy, including maternal health and any prenatal ultrasound findings suggesting gastrointestinal anomalies
Onset and character of vomiting (non-bilious vs
bilious)
Passage of meconium
Presence of other congenital anomalies
Family history of similar conditions.
Physical Examination:
Thorough abdominal examination, noting distension, tenderness, and palpable masses
Auscultation for bowel sounds
Assessment of hydration status and vital signs
Examination for dysmorphic features suggestive of chromosomal abnormalities like Down syndrome.
Investigations:
Plain abdominal radiography (supine and erect views): may show gastric and duodenal distension with an air-fluid level, and absence of gas in the distal bowel
Upper gastrointestinal (UGI) contrast study: the gold standard for diagnosis, showing a dilated stomach and duodenal bulb with a sharply demarcated obstruction at the level of the atresia or stenosis, creating the classic "double-bubble" sign
Ultrasound: can sometimes detect duodenal dilatation antenatally or postnatally
Chromosomal analysis: recommended due to the high association with Down syndrome.
Differential Diagnosis:
Other causes of neonatal intestinal obstruction: Malrotation with volvulus (bilious vomiting is a key feature)
Pyloric stenosis (non-bilious vomiting, but typically presents later, around 3-6 weeks)
Jejunal atresia
Distal intestinal atresias
Imperforate anus
Congenital bands
Meconium ileus.
Management
Initial Management:
Immediate resuscitation and stabilization are paramount
Nasogastric (NG) tube insertion for gastric decompression and to prevent further vomiting and aspiration
Intravenous (IV) fluid resuscitation to correct dehydration and electrolyte imbalances, typically with Ringer's lactate or normal saline
Broad-spectrum IV antibiotics to cover potential infections and aspiration
Blood glucose monitoring.
Surgical Management:
Surgical correction is the definitive treatment and is usually an urgent procedure
The goal is to bypass the obstruction
Common surgical procedures include: Duodenoduodenostomy (diamond-shaped anastomosis) or duodenojunostomy
Ladd procedure may be performed concurrently if malrotation is present
The approach is typically laparotomy, though laparoscopy is increasingly being used in select centers.
Supportive Care:
Continuous NG tube decompression
Strict monitoring of fluid balance, electrolytes, and acid-base status
Nutritional support via total parenteral nutrition (TPN) until enteral feeds are tolerated
Careful monitoring for signs of infection, anastomotic leak, or wound complications
Pain management
Respiratory support if needed.
Complications
Early Complications:
Anastomotic leak or breakdown
Sepsis
Wound infection
Pneumonia due to aspiration
Prolonged ileus
Biliary obstruction if the distal common bile duct is involved in the atretic segment
Nutritional deficiencies.
Late Complications:
Stricture at the anastomosis site
Adhesive intestinal obstruction
Failure to thrive
Recurrent vomiting due to motility disorders or partial obstruction.
Prevention Strategies:
Early diagnosis and prompt surgical intervention
Meticulous surgical technique
Aggressive postoperative care, including adequate hydration, nutrition, and monitoring for complications
Careful attention to fluid and electrolyte balance.
Prognosis
Factors Affecting Prognosis:
The presence and severity of associated congenital anomalies, particularly chromosomal abnormalities, significantly impact prognosis
The timing of diagnosis and surgical intervention is crucial
The absence of other major organ system anomalies generally leads to a better outcome.
Outcomes:
With timely diagnosis and surgical repair, the prognosis for isolated duodenal atresia is generally good, with high survival rates (over 90%)
Infants with Down syndrome or multiple congenital anomalies have a poorer prognosis.
Follow Up:
Regular follow-up visits are essential to monitor growth and development
Assessment for feeding tolerance, weight gain, and signs of recurrent obstruction or complications
Long-term nutritional assessment may be required
Echocardiography and audiometry screening are often recommended, especially if Down syndrome is present.
Key Points
Exam Focus:
The "double-bubble" sign on imaging is pathognomonic for duodenal obstruction
High association with Down syndrome (trisomy 21)
Non-bilious vomiting and abdominal distension are hallmark symptoms
Prompt surgical decompression and bypass are the mainstay of management.
Clinical Pearls:
Always consider duodenal atresia in any neonate with persistent non-bilious vomiting
The absence of distal air on plain films, coupled with dilated proximal loops, is highly suggestive
If the diagnosis is unclear, an UGI contrast study is essential
Aggressive fluid resuscitation and NG decompression are critical before surgery.
Common Mistakes:
Mistaking non-bilious vomiting for simple reflux
Delaying diagnosis due to attributing symptoms to other causes
Inadequate preoperative stabilization, leading to increased surgical risk
Failure to investigate for associated anomalies, especially Down syndrome.