Hirschsprung Pull-Through

Hirschsprung-associated enterocolitis - fever, abdominal distension and explosive foul diarrhea with fast dehydration, and mortality near 10% against 0 to 2% without it. A child who looks septic on the morning of surgery is a resuscitation, not a case start.

Full stomach from obstruction - the aganglionic segment stays tonically contracted, so bowel above it is loaded and distended. Decompress the stomach before induction and treat the acutely obstructed or enterocolitic infant as an RSI, not an inhalational induction.

Distension and diaphragmatic splinting - a tense abdomen cuts functional residual capacity in a child whose oxygen consumption is already high, so desaturation comes fast. Preoxygenate properly and expect compliance to improve once the abdomen is opened.

Access above the waist - no IV lines and no monitors go on the lower extremities, because the legs go up into the frame and the perineum is inside the prep. Site two upper-limb cannulae, 20 to 22 gauge, before anything is draped.

Both ends at once - the table is turned 90 degrees so the surgeon reaches abdomen and perineum while you keep the head. Once the drapes are up you cannot get back to the airway, so tape the tube hard and confirm depth before you lose access.

Mid-case position change - the child starts supine and moves to lithotomy for the perineal phase, with a full reprep and redrape. Pad the lateral fibular head against common peroneal compression, protect the eyes, and recheck breath sounds once the hips are flexed.

Radiant heat loss - a small child with an open abdomen and exposed bowel loses heat mostly by radiation. Warm the room to 75 to 80 degrees F before the child arrives and run forced air plus fluid warming, because a cold start cannot be recovered later.

Fluid and glucose - maintenance of NS or LR near 10 mL/kg/h, plus 10 to 20 mL/kg to offset the bowel prep deficit, titrated to urine output of 1 mL/kg/h through a catheter. An infant needs a separate dextrose infusion, not sugar in the replacement fluid.

Proportional blood loss - 5 to 10 mL/kg is trivial in absolute terms but a real slice of a 10 kg child's blood volume. Have a hematocrit and a type and screen, and use 5% albumin when volume has to go in quickly.

Caudal analgesia - sacral anatomy is normal in this disease, so a caudal block or a caudally threaded catheter covers both the abdominal and perineal fields. Place it before the perineal prep, since the entry site sits inside the surgical field.

Relaxation versus analgesia - a working block covers the pain but not the abdominal wall relaxation needed to mobilize the colon and bring it down. Run a low-dose volatile with an intermediate non-depolarizer dosed to the surgical need, not to the block.

Trisomy 21 - present in about 1 in 20 of these children. Get an echo result rather than assuming a murmur was sorted, anticipate a smaller tube than age predicts and airway obstruction on emergence, and move the neck gently through positioning.

Frozen-section dead time - the case stalls while the pathologist confirms ganglion cells, sometimes repeatedly, so the anesthetic has to hold a stable plane through unpredictable pauses. Budget 3 to 4 hours open, roughly half that for a perineal single-stage.

Extubation and disposition - the plan is a tube out at the end, which needs the child warm and the block working, then PICU. Afterwards nothing goes in the rectum: no rectal probe and no rectal drugs, because the coloanal anastomosis leaks in about 5%.

Hirschsprung's disease is a congenital absence of ganglion cells that begins at the dentate line and extends proximally for a variable distance, so the involved bowel cannot relax and sits tonically contracted. That produces a functional obstruction: stool backs up, the proximal colon dilates, and the child presents with severe constipation or frank obstruction. The transition to normally innervated bowel lies in the distal colon in about 80% of cases and in the small bowel in 10%. Stasis above the aganglionic segment allows bacterial overgrowth and mucosal injury, producing Hirschsprung-associated enterocolitis (HAEC), a toxic dehydrating illness that can kill before any definitive operation and is the reason a severely affected infant may be decompressed with an urgent colostomy first. Incidence is roughly 1 in 5,000 with a 4:1 male predominance.

Diagnosis - a contrast enema suggests the transition zone and a rectal biopsy confirms the disease by showing absence of ganglion cells.

Leveling - laparoscopy, an umbilical incision, or a left lower quadrant incision is used to biopsy up the colon until frozen section identifies ganglionated bowel.

Mobilization - the colon and rectal mesentery are divided and the proximal colon freed so it will reach the anus without tension.

Transanal dissection - a circumferential incision in the rectal mucosa 5 to 10 mm above the pectinate line starts a submucosal dissection carried up to meet the abdominal dissection.

Muscular cuff - the rectal muscular cuff is incised circumferentially and split posteriorly so the pull-through segment can pass through it.

Pull-through - rectum and sigmoid are drawn down through the cuff, the colon is transected at a level confirmed ganglionic by frozen section, and a single-layer end-to-end coloanal anastomosis is completed transanally.

Staging - a one-stage repair avoids a stoma altogether; the traditional route brings out a leveling colostomy first and closes it at a later operation.

Enterocolitis is not finished by the operation. It can appear days to weeks after a technically perfect pull-through, and the picture is the same one you saw preoperatively: fever, a distending abdomen and explosive diarrhea in a child who decompensates quickly. Say that out loud at the PICU handover rather than leaving it as an assumption.