Vitello-intestinal Duct (VIT)
Definition
- Vitello-intestinal duct (VIT): This embryonic duct links the yolk sac to the developing midgut. It typically closes by the seventh week of pregnancy.
Embryology
- Normal development: The duct generally closes and disappears by the seventh week of gestation.
- Pathology: Failure to obliterate can result in various congenital abnormalities.
Congenital Anomalies Associated with Persistent VIT
| Anomaly | Description | Clinical Features | Diagnosis | Management |
|---|---|---|---|---|
| Meckel’s Diverticulum | A true diverticulum on the anti-mesenteric side of the ileum | Usually asymptomatic; may cause bleeding, obstruction, or infection | Technetium-99m scan, CT, MRI | Surgical removal if symptoms present |
| Vitelline Fistula | An open duct connecting the ileum to the umbilicus | Discharge of intestinal contents from the navel | Clinical examination, fistulography | Surgical removal |
| Vitelline Cyst | A cystic remnant found between the umbilicus and the ileum | Can cause abdominal pain or be discovered accidentally | Ultrasound, CT | Surgical excision |
| Fibrous Bands | Fibrous connections between the ileum and umbilicus | Potential cause of small bowel obstruction | X-ray, CT | Surgical intervention if symptomatic |
Diagnostic Approach
- History and Physical Examination:
- Check for umbilical anomalies or signs of bowel obstruction.
- Investigate family history for congenital issues.
- Imaging:
- Ultrasound: First-line imaging.
- Technetium-99m scan: Particularly for Meckel’s diverticulum.
- CT/MRI: Provides detailed anatomical information.
Management
- Asymptomatic cases: Often managed with regular monitoring.
- Symptomatic cases:
- Surgery: Removal of the remnant or treatment of complications.
- Preoperative care: Ensure proper hydration, balance electrolytes, and provide antibiotics if infection is suspected.
Prognosis
- Generally excellent following surgical treatment.
- Regular follow-ups are crucial to detect any potential complications early.
Rule of 2s in Meckel’s Diverticulum
- Occurs in 2% of the population.
- Located within 2 feet of the ileocecal valve.
- Usually about 2 inches long.
- Often symptomatic before age 2 but can be asymptomatic.
- Contains two types of ectopic tissue: gastric and pancreatic.
- More common in males than females, by a factor of two.
Summary
- The vitello-intestinal duct, an embryonic remnant, can lead to several congenital anomalies if it remains.
- These anomalies include Meckel’s diverticulum, vitelline fistula, vitelline cyst, and fibrous bands.
- Diagnosis involves clinical evaluation and imaging.
- Management primarily involves surgery, particularly for symptomatic cases, with a generally good prognosis.
Key Points
- The vitello-intestinal duct should normally close by the seventh week of gestation.
- Persistence can cause congenital anomalies such as Meckel’s diverticulum, vitelline fistula, vitelline cyst, and fibrous bands.
- Diagnosis is often achieved through imaging studies like ultrasound, CT, and Technetium-99m scan.
- Symptomatic cases usually require surgical intervention.
- Prognosis is generally excellent with proper surgical management.