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Duodenal Atresia (DA) is a congenital condition in which the lumen of the duodenum fails to recanalize, resulting in complete obstruction of the small intestine, typically at or just distal to the ampulla of Vater.
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It is a common cause of neonatal intestinal obstruction.
| Feature | Details |
|---|---|
| Definition | Congenital complete obstruction of the duodenum |
| Common location | Second portion of duodenum (near ampulla of Vater) |
| Cause | Failure of duodenal recanalization during embryogenesis (weeks 6–8) |
| Incidence | ~1 in 6,000 to 10,000 live births |
| Sex | Slight male predominance |
Associated conditions:
| Condition | Frequency / Note |
|---|---|
| ‣ | ~30% of duodenal atresia cases |
| ‣ | Common associated anomaly |
| Malrotation | May co-occur |
| Cardiac anomalies | ASD, VSD, AVSD (especially with Trisomy 21) |
| Renal/urinary tract anomalies | Occasionally seen |
Within first 24–48 hours of life:
| Modality | Imaging features |
|---|---|
| US (prenatal) | • Polyhydramnios |
| • Double-bubble sign may be seen | |
| • Dilated stomach and proximal duodenum | |
| XR (post-natal) | • ‣ (CLASSIC): Dilated stomach and proximal duodenum separated by pylorus |
| • No distal bowel gas: Indicates complete obstruction (vs incomplete/malrotation) | |
| (if distal gas is present: consider duodenal stenosis, annular pancreas, or malrotation with volvulus) | |
| Barium | • Used to rule out malrotation with midgut volvulus |
| • Shows abrupt cutoff at 2nd part of duodenum |
Duodenal atresia. (A) Plain radiograph of the abdomen showing the classical “double bubble” sign with no gas distally in a case of duodenal atresia. (B) Plain abdominal radiograph of another newborn with duodenal atresia showing the distended stomach and duodenum with air-fluid levels and no distal gas consistent with the double bubble sign of duodenal atresia. (C) Findings were confirmed intraoperatively
Jain SN, Shah RS, Modi T, Varma RU. ICRI White Paper: An Update on Role of Conventional Radiography in Imaging of Pediatric Gastrointestinal Tract. Indian Journal of Radiology and Imaging - New Series/Indian Journal of Radiology and Imaging/Indian Journal of Radiology & Imaging. 2022;33(02):218-229. doi:10.1055/s-0042-1759481
Differential Diagnosis for Double-Bubble Sign
| Condition | Distal Gas | Notes |
|---|---|---|
| Duodenal atresia | Absent | Complete obstruction |
| Duodenal web/stenosis | Present | Partial obstruction |
| Annular pancreas | Variable | External compression |
| Malrotation/volvulus | Present or absent | Needs urgent differentiation |