Hirschsprung's Pull-Through
What the Examiner Expects
Definitive surgical treatment for Hirschsprung's disease — resection of the aganglionic bowel segment and pull-through of normally innervated bowel to the anus. The examiner expects you to diagnose with rectal suction biopsy (absence of ganglion cells, presence of hypertrophied nerve trunks — acetylcholinesterase staining), recognize that the disease extends from the anus proximally (rectosigmoid in 75% of cases), and describe the pull-through techniques: Soave (endorectal — dissection in the submucosal plane, preserving the muscular cuff), Duhamel (retrorectal — ganglionic bowel pulled posterior to the aganglionic rectum), or Swenson (full-thickness rectal dissection). Most can be done as a primary single-stage transanal pull-through.
Key Examiner Focus Points
- Absence of ganglion cells in Meissner's and Auerbach's plexuses — distal bowel fails to relax
- Diagnosis: rectal suction biopsy showing absent ganglion cells and hypertrophied nerve trunks
- Transition zone: aganglionic (narrowed) to ganglionic (dilated) bowel
- Pull-through: resect aganglionic segment, pull ganglionated bowel to the anus (Soave, Duhamel, or Swenson)
- Enterocolitis is the most dangerous complication (both pre- and post-repair)
Common Curveballs
Newborn with Hirschsprung's develops abdominal distension, fever, and explosive diarrhea
Hirschsprung-associated enterocolitis (HAEC) — a life-threatening complication. Immediate treatment: NPO, IV antibiotics, aggressive IV fluid resuscitation, and rectal irrigations (warm saline via a large rectal tube to decompress the colon). If the child does not improve rapidly, emergent diverting colostomy (in ganglionic bowel, confirmed by frozen section) is required.
Rectal biopsy shows ganglion cells are absent all the way to the transverse colon
Total colonic aganglionosis (5% of cases). The pull-through procedure must extend to the ganglionic small bowel. Options include a Duhamel procedure with a long aganglionic pouch side-to-side with ileum, or an extended resection with ileal J-pouch-anal anastomosis. Serial frozen sections of the proximal bowel are essential to confirm the transition zone.