Duodenal Atresia (Children)
Duodenal Atresia is a congenital malformation of the duodenum, usually presenting in neonates with early bilious vomiting. It is classically associated with the “double bubble” sign on abdominal X-ray and is one of the few neonatal surgical emergencies where outcome is excellent after prompt surgery.
About 🚼
- Definition: Congenital obstruction of the duodenum due to failure of recanalisation in fetal life.
- Onset: Presents in the neonatal period, often within hours of the first feed.
- Prognosis: Excellent with surgical correction; without surgery, it is uniformly fatal due to inability to establish enteral nutrition.
Aetiology & Associations 🧬
- Embryological defect: Failure of duodenal lumen to recanalise between weeks 8–10 of gestation.
- Genetic links: ~30–40% associated with Trisomy 21 (Down syndrome).
- Other syndromes: Can be part of VACTERL (vertebral, anal, cardiac, tracheoesophageal, renal, limb anomalies).
- Polyhydramnios: Common antenatal finding due to impaired fetal swallowing.
- Other anomalies: Cardiac defects (ASD, VSD) and renal tract malformations often coexist.
Epidemiology 📊
- Incidence: 1 in 6,000–10,000 live births worldwide.
- Sex ratio: ~1:1 (no clear male predominance).
- Most cases are sporadic (non-inherited).
Clinical Features 👶
- Vomiting: Bilious (green) vomiting within hours of birth (distal to ampulla of Vater).
- Abdominal distension: Especially upper abdomen due to duodenal dilatation.
- Electrolyte imbalance: Hypochloraemic metabolic alkalosis from loss of gastric acid.
- Failure to thrive: Dehydration, weight loss if diagnosis delayed.
Investigations 🔬
- Abdominal X-Ray: “Double bubble” sign – gas in stomach + proximal duodenum, no distal gas.
- Prenatal ultrasound: May reveal polyhydramnios and double bubble sign, allowing antenatal diagnosis.
- Contrast study: Considered if obstruction site uncertain.
- Echocardiogram: Screen for congenital heart disease (especially in Down syndrome).
Differential Diagnosis 🩺
- Pyloric stenosis: Later presentation, non-bilious vomiting, hypertrophied pylorus on ultrasound.
- Malrotation with volvulus: Bilious vomiting with acute abdominal compromise – surgical emergency.
- Jejunoileal atresia: Multiple dilated loops of bowel, not classic double bubble.
- Annular pancreas: Pancreatic tissue encircling duodenum causing obstruction.
Management 💉
- Antenatal planning: If diagnosed in utero → delivery at tertiary neonatal surgical centre.
- Initial stabilisation:
- NG tube insertion for gastric decompression.
- IV fluids + electrolyte correction (esp. hypochloraemia, hypokalaemia).
- Surgery: Standard = duodenoduodenostomy (end-to-side anastomosis). Sometimes duodenojejunostomy or bypass depending on anatomy.
- Post-op care:
- Gradual reintroduction of feeds.
- Parenteral nutrition until full enteral tolerance.
- Monitor for leaks, strictures, delayed gastric emptying.
Prognosis 🌟
- Survival >95% in high-resource settings with early surgery.
- Outcomes depend on presence of associated anomalies (esp. congenital heart disease).
Classic Exam Pearls 📖
- Newborn with bilious vomiting + double bubble sign → duodenal atresia until proven otherwise.
- Association with Down syndrome is a high-yield exam fact.
- Polyhydramnios in antenatal scan → think duodenal obstruction.
References 📚
