Vitelline Duct (Omphalomesenteric Duct

🧬 Vitelline Duct (Omphalomesenteric Duct)

📷 Insert Illustration Here (Vitelline Duct Remnants Diagram)

Recommended: Meckel’s diverticulum, fistula, cyst, fibrous band

📌 Definition:
The vitelline duct is an embryologic connection between the midgut and yolk sac, which normally obliterates by 7th week of gestation.

🔬 Embryology:

• Connects ileum → yolk sac
• Provides early nutrition before placental circulation
• Normally disappears completely

⚠️ Vitelline Duct Remnants:

1. Meckel’s Diverticulum (Most Common)

• True diverticulum (all layers)
• Located on antimesenteric border

Rule of 2s:

• 2% population
• 2 feet from ileocecal valve
• 2 inches long
• 2 types ectopic mucosa
• Presentation before age 2

Complications: painless bleeding, obstruction, diverticulitis

2. Vitelline Fistula
Entire duct persists → fecal discharge from umbilicus

3. Vitelline Cyst
Central portion persists → cystic mass

4. Fibrous Band
Risk of volvulus and intestinal obstruction

🧪 Clinical Clues:

• Painless rectal bleeding in child → Meckel’s diverticulum
• Feces from umbilicus → Vitelline fistula
• Differentiate from urachus: urine vs feces

🔍 Diagnosis:
Technetium-99m pertechnetate scan (Meckel scan)

💉 Management:

• Surgical resection (symptomatic)
• Often removed if found incidentally in young patients

💡 High-Yield Points:

• Most common remnant → Meckel’s diverticulum
• Painless GI bleeding = Meckel’s until proven otherwise
• Contains ectopic gastric mucosa → ulceration
• Feces (vitelline) vs urine (urachus)