Colorectal Quiz Episode 27: Delayed Hirschsprung Disease

Of 1000 constipated patients, approximately 900 can be managed by pediatrician with diet and laxatives, 90 of the remaining 100 by gastroenterologist, leaving 10 requiring surgical evaluation and 1 needing surgical intervention

Red flags for Hirschsprung referral include marginal weight gain and requirement for rectal stimulation to produce any bowel movement

90% of Hirschsprung disease is diagnosed in the first month of life

Older children with delayed Hirschsprung diagnosis typically never develop enterocolitis despite years of symptoms

In the recto-anal inhibitory reflex (RARE), smooth muscle normally relaxes when rectum is distended; in Hirschsprung disease and internal sphincter achalasia, the muscle contracts instead

Coordinated OR approach: perform anorectal manometry awake with anesthesia standby, if RARE absent then proceed with biopsy, and consider Botox injection for potential internal sphincter achalasia treatment

Anorectal manometry is not reliable under age one year, though many gastroenterologists disagree with this assessment

Anorectal manometry requires awake, cooperative patient to obtain accurate resting pressure for external sphincter and pelvic floor information; sedated patients will not have resting pressure

Dyssynergia (sphincter not working in coordination with body) is often seen in 3-year-old age group during potty training and can be detected on anorectal manometry

Suction rectal biopsies are taken at 1 centimeter, 2 centimeters, and 3 centimeters from the anal verge using the suction biopsy gun

Helen Noblett, a pediatric surgeon in Melbourne, Australia, developed the suction rectal biopsy gun and was the only woman among early Hirschsprung surgery icons

For profuse rectal bleeding after suction biopsy, management is digital rectal insertion with direct pressure against the sacrum to tamponade bleeding from the posterior rectal wall

Suction rectal biopsy is reliable under 6 months of age, gray zone between 6-12 months depending on baby size, and over 10-12 months should transition to open biopsy in OR

Hirschsprung diagnosis requires both absence of ganglion cells on 100 levels AND presence of hypertrophic nerves; do not operate on absence of ganglion cells alone

Adequate rectal biopsy specimen must contain sufficient submucosa to determine specimen adequacy

Hypertrophic nerves are defined as greater than 40 microns, a standard defined by Margaret Collins

Rectal biopsy showing squamous epithelium indicates inadequate specimen that is too distal

Rectal biopsy specimen filled with eosinophils suggests milk protein allergy, which can mimic Hirschsprung appearance but is ruled out by presence of ganglion cells

If ganglion cells are present, it is not Hirschsprung disease regardless of whether hypertrophic nerves are present; hypertrophic nerves in this context are secondary to constipation

Contrast enema in Hirschsprung should show rectum as widest part of colon; inverted ratio with sigmoid wider than rectum suggests Hirschsprung

Older children with Hirschsprung typically have very short segment aganglionosis and their proximal colon can overcome the aganglionic segment most of the time, which is how they get by until diagnosis

Rectal irrigations should be taught to families when moderate concern for Hirschsprung exists but biopsy is refused, as potential preventive measure

For severely distended colon in delayed Hirschsprung, options include aggressive irrigations for 1-2 months, leveling colostomy, or ileostomy; preference is for irrigations first, then ileostomy if diversion needed rather than leveling colostomy

Tapered colon segments do not function well; preference is to decompress with stoma, wait for colon to shrink, then perform pull-through to normal caliber proximal sigmoid or left colon

Technique for anastomosing slightly larger circle to slightly smaller circle: place stitches at 12, 6, 3, and 9 o'clock positions, then continue dividing between those stitches

Laparoscopic approach is safer than transanal-only for obtaining true level confirmation with full-thickness biopsy and performing mesenteric dissection, thereby decreasing transanal dissection time and reducing sphincter injury risk

Transanal-only dissection might be appropriate in older children with rectal transition zone where level is very confident and operation can be performed at anal level without sphincter stretching, preferably in prone position

Patient underwent primary laparoscopic-assisted Swenson procedure, recovered well postoperatively with 5-day hospital stay, and is currently stooling well with flatter abdomen