Intestinal Atresia and Stenosis

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Intestinal Atresia/Stenosis - Embryo's Oopsie Daisy

  • Definitions:
    • Atresia: Complete congenital obstruction of intestinal lumen; a gap.
    • Stenosis: Incomplete obstruction or narrowing of intestinal lumen.
  • Incidence: Affects ~1 in 1500-5000 live births.
  • General Embryological Basis:
    • Failure of recanalization: Fetal gut's solid cord stage (Weeks 8-10) fails to re-open.
    • Vascular accidents: Intrauterine ischemic events cause bowel segment resorption. Types of Intestinal Atresia

⭐ Intestinal atresia is the most common cause of congenital intestinal obstruction in newborns.

Duodenal Atresia - Double Bubble Classic

  • Embryology: Failure of recanalization of duodenum (typically 8th-10th week gestation).
  • Clinical Features:
    • Bilious vomiting (85%) within hours of birth.
    • Epigastric fullness/distension.
    • Polyhydramnios in utero (50%).
  • Associations:
    • Down syndrome (Trisomy 21) (~30%).
    • 📌 VACTERL (Vertebral, Anal, Cardiac, Tracheo-Esophageal, Renal, Limb defects).
    • Annular pancreas, malrotation.
  • Diagnosis:
    • X-ray: Classic "double bubble" sign (stomach and proximal duodenum).
    • Absence of distal gas (indicates complete obstruction). X-ray: Double bubble sign in duodenal atresia

⭐ Approximately 30% of infants with duodenal atresia have Down syndrome (Trisomy 21).

Jejunoileal & Colonic Atresia - Vascular Event Aftermath

  • Etiology: In-utero mesenteric vascular accident (ischemic insult) → bowel necrosis & resorption.

    ⭐ Jejunoileal atresias are most commonly caused by an in-utero mesenteric vascular accident.

  • Jejunoileal (JI) Atresia Classification (Louw & Barnard):
    TypeDescription
    IMembranous web
    IIFibrous cord between blind ends
    IIIaMesenteric gap, V-shaped
    IIIbApple-peel/Christmas tree deformity
    IVMultiple atresias (string of sausages)
    Louw & Barnard Classification of Jejunoileal Atresia
  • Clinical: Bilious vomiting (first 24-48h), abdominal distension, failure to pass meconium.
  • Diagnosis:
    • X-ray: Multiple air-fluid levels, no distal gas.
    • Contrast enema: Microcolon; rules out colonic atresia/meconium ileus.
  • Colonic Atresia: Rarer; similar etiology; types (membranous, cord, separation).

Diagnosis & Management - Spot & Snip Strategy

  • Antenatal Diagnosis: Ultrasound showing polyhydramnios.

    ⭐ Polyhydramnios is a significant antenatal indicator, especially for proximal intestinal atresias like duodenal atresia.

  • Postnatal Diagnosis:
    • Plain abdominal X-ray (e.g., "double bubble" sign).
    • Upper GI contrast study if needed; contrast enema for distal obstruction.
  • Preoperative Stabilization: NPO, nasogastric/orogastric tube decompression, IV fluids, electrolyte correction, prophylactic antibiotics.
  • Surgical Principles:
    • Resection of dilated proximal bowel, primary end-to-end anastomosis.
    • Tapering enteroplasty for significant caliber discrepancy.
    • Stoma creation if primary anastomosis is unsafe.
  • Postoperative Complications: Anastomotic leak, stricture formation, short bowel syndrome.

High‑Yield Points - ⚡ Biggest Takeaways

  • Duodenal atresia is strongly associated with Down syndrome and presents with a classic "double bubble" sign on X-ray.
  • Jejunoileal atresias typically result from in-utero vascular accidents or ischemic insults.
  • The "apple peel" or "Christmas tree" deformity is characteristic of Type IIIb jejunal atresia.
  • Bilious vomiting shortly after birth is a cardinal sign of intestinal obstruction distal to the ampulla of Vater.
  • Maternal polyhydramnios is a common antenatal finding, especially with proximal intestinal atresias.
  • Intestinal stenosis causes incomplete obstruction, often presenting with more subtle or delayed symptoms than atresia.
  • Definitive management for all intestinal atresias and symptomatic stenosis is surgical repair.

Practice Questions: Intestinal Atresia and Stenosis

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X-ray feature of pyloric stenosis is –

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Flashcards: Intestinal Atresia and Stenosis

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_____ is characterized by dilation of the stomach and proximal duodenum with a "double bubble" sign on X-ray

TAP TO REVEAL ANSWER

_____ is characterized by dilation of the stomach and proximal duodenum with a "double bubble" sign on X-ray

Duodenal atresia

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