A male infant presented with distension of abdomen shortly after birth with delayed passage of meconium. Subsequently a full-thickness biopsy of the rectum was performed. The rectal biopsy is likely to show:

Hyalinization of the muscular coat

A newborn baby presented with a failure to pass meconium in the immediate postnatal period. The pediatrician also notices visible yet ineffective peristalsis, and abdominal distention. A radiological contrast enema demonstrated a narrow conical segment and a dilated proximal bowel. A diagnosis of Hirschsprung disease was made. Which of the following is a cause of the condition in the patient?

Failure of migration of neural crest cells

Persistence of embryonic structures in the bowel wall

Congenital obstruction due to external factors

Abnormal peristalsis due to neural dysfunction

All are true about Hirschsprung disease Except

Absence of ganglion cells within the affected segment

Dilation proximal to the affected segment.

Hirschsprung disease typically presents with a failure to pass meconium in the immediate postnatal period.

What are the primary criteria for considering operative treatment in Hirschsprung's disease?

Has failed to respond to conservative treatment

Is at least 8 kg in weight and thriving

Which of the following statements about Hirschsprung disease is incorrect?

The non-peristaltic affected segment is dilated

Absence of ganglion cells in the involved segment

Swenson, Duhamel, and Soave are surgical procedures for this condition

Hypochloremia, hypokalemia, and alkalosis are typically seen in which of the following conditions?

Congenital hypertrophic pyloric stenosis

Hirschsprung's Disease: High-Yield Surgery Lessons

HD 101 - Gut's Missing Ganglia

Congenital aganglionic megacolon causing functional bowel obstruction.
Embryology: Defective craniocaudal migration of neural crest cells (NCCs) during weeks 4-12 gestation.
- NCCs fail to populate distal bowel.
- RET gene mutations are frequently implicated.
Pathophysiology: Absence of ganglion cells (Auerbach's & Meissner's plexuses) in distal segment.
- Results in a tonically contracted aganglionic segment.
- Leads to proximal bowel dilatation.

⭐ The aganglionosis always starts at the anus and extends proximally; rectosigmoid is affected in ~80% of cases.

HD Signs - Blocked Baby Blues

Feature	Neonates	Older Infants/Children
Meconium	Failure to pass (>24-48h) - cardinal sign	History of delayed passage
Vomiting	Bilious	Occasional, may be non-bilious
Abdomen	Progressive distension	Chronic distension, palpable fecal masses
Stools	Obstipation; explosive on DRE	Chronic constipation, ribbon-like, foul
Systemic	Enterocolitis risk (fever, diarrhea)	Failure to thrive (FTT), malnourishment

HD Detective - Unmasking Aganglionosis

Suspicion: Failure to pass meconium (>24-48h), bilious emesis, abdominal distension, chronic constipation, enterocolitis episodes.
Imaging:
- AXR: Dilated proximal bowel loops, paucity of distal gas.
- Contrast Enema (Barium/Gastrografin): Transition zone (key!), narrow spastic distal segment, dilated proximal bowel. Retained contrast >24h.
Anorectal Manometry: Absence of Rectoanal Inhibitory Reflex (RAIR); useful if enema equivocal or in older children.
Gold Standard: Rectal Biopsy
- Suction biopsy (2-3 cm above dentate line) or full-thickness.
- Histology: Absence of ganglion cells (submucosal/myenteric plexuses).
- Key: Hypertrophied nerve trunks (Acetylcholinesterase positive staining).
⭐ Gold standard: Full-thickness rectal biopsy showing aganglionosis & hypertrophied, AChE-positive nerve trunks. 📌 HD: Transition Zone, Aganglionic Biopsy. (TZAB)

HD Solutions - Surgical Fixes & Woes

Core Principle: Resect aganglionic segment, pull-through healthy bowel to anus.
Key Procedures:
- Swenson: Original pull-through; full-thickness resection.
- Soave: Endorectal mucosectomy, ganglionated bowel pulled through muscular cuff. (📌 Soave = Submucosal/Stripping)
- Duhamel: Retrorectal transanal pull-through; side-to-side anastomosis.
- Minimally Invasive: Laparoscopic or transanal (TEPT).
Post-Op Woes:
- Hirschsprung-Associated Enterocolitis (HAEC):
  - Signs: Fever, distension, explosive foul diarrhea.
  - Rx: Aggressive! IV fluids, antibiotics, rectal irrigations.
- Anastomotic stricture/leak.
- Persistent constipation/soiling.

Surgical procedures for Hirschsprung's disease

⭐ HAEC remains the leading cause of morbidity and mortality in HD patients, occurring in up to 20-30% even after corrective surgery.

High‑Yield Points - ⚡ Biggest Takeaways

Congenital aganglionosis of the distal bowel, most commonly rectosigmoid.

Results from failed neural crest cell migration to the hindgut.

Neonates: delayed meconium passage (>24-48 hours), bilious vomiting, abdominal distension.

Gold standard diagnosis: Rectal biopsy showing absent ganglion cells.

Contrast enema: transition zone between narrowed aganglionic and dilated ganglionic bowel.

Anorectal manometry: absent rectoanal inhibitory reflex (RAIR).

Treatment: Surgical resection of affected segment; risk of Hirschsprung-Associated Enterocolitis (HAEC).

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