Hirschsprung's Disease with Dr. Marc Levitt

Many non-Hirschsprung's medical conditions can mimic Hirschsprung's disease in the newborn, including maternal magnesium sulfate administration, hypothyroidism, opiate exposure transmitted to the baby, and milk protein allergy after feeding.

Surgical conditions that can mimic Hirschsprung's disease include anorectal malformation (even with fistula), small left colon syndrome, and colonic atresia.

Ten percent of patients with meconium plug have Hirschsprung's disease, so suction rectal biopsy is performed routinely even after successful plug passage.

In meconium plug cases, the initial contrast study may show a dilated rectosigmoid that does not appear consistent with Hirschsprung's, but after plug passage a repeat contrast study will reveal a more obvious transition zone.

In total colonic Hirschsprung's disease, there is often no obvious transition zone on contrast study.

Suction rectal biopsy is a gold standard for ruling out Hirschsprung's disease, though some centers proceed directly to biopsy without contrast study.

Dr. Levitt prefers to have a contrast study as a surgical GPS map of the colon before going to the operating room.

The physiologic obstruction in Hirschsprung's disease leads to stasis, which causes bacterial overgrowth and bacterial translocation because mucosal integrity is abnormal in these patients.

A constipated baby without Hirschsprung's disease will not develop enterocolitis because their mucosal integrity and IgA levels are normal.

Down syndrome patients with Hirschsprung's disease have worse enterocolitis because they have a weaker immune barrier.

Irrigations must follow a written protocol: use a 20 French soft silicone Foley catheter, inject 10-20 cc aliquots of warm saline, remove the syringe to let fluid drip back, advance the catheter a few centimeters, and repeat to wash the entire rectosigmoid over approximately 30 minutes, two to three times per day.

If irrigations do not reach the transition zone, the baby's distension will not improve and irrigations will not be effective.

When irrigations fail despite correct technique, the surgeon must decide between a leveling colostomy (bringing dilated bowel to the surface, ideally with frozen section confirmation of ganglion cells) or an ileostomy with colonic biopsies.

Dr. Levitt's personal preference is ileostomy with colonic biopsies because the baby will almost certainly thrive, all pathology data on the colon can be obtained electively, and the surgeon does not need frozen section at 3 a.m., though this approach requires three operations instead of two.

In many parts of the world, ileostomy is difficult to manage and babies can become dehydrated quickly, making leveling colostomy more appropriate in those settings.

The risk of a leveling colostomy is opening the stoma in the transition zone rather than in dilated ganglionic bowel.

A loop ileostomy where the two limbs are equal is inappropriate because stool will jump across into the aganglionic segment, causing continued distension and potential enterocolitis despite diversion.

For loop diversion, Dr. Levitt recommends a Turnbull ileostomy (cutting the bowel completely on one side of the loop, inserting a finger to evert it into an end-stoma appearance with the distal limb flat on the skin) or a divided ileostomy with the distal limb tacked to the proximal limb.

Post-pull-through Hirschsprung's patients present with two distinct problems: the obstructed patient and the soiling patient, and these two phenotypes rarely overlap.

The typical obstructed patient had their pull-through, did well for about six months, then developed chronic distension, recurrent enterocolitis episodes, and sometimes failure to thrive from poor oral intake due to distension.

Anatomic causes of post-pull-through obstruction include: inadequate Soave cuff resection, rolled-up or refused cuff creating a circumferential rubbery ring outside the pull-through, twisted pull-through (180 or 360 degrees), Duhamel spur where the two lumens were not successfully joined, large Duhamel pouch extending into the pelvis, stricture, and transition zone pull-through.

A twisted pull-through can be detected on digital exam (inability to advance the finger into the pelvis, hitting a wall) and on contrast study with oblique angles.

A Soave cuff can be detected on digital exam as a rubbery circumferential ring and on lateral contrast study as widening of the presacral space, with the pull-through pushed forward rather than hugging the sacrum.

Dr. Levitt's routine for the obstructed post-pull-through patient is contrast study, examination under anesthesia to look for anatomic causes, biopsy, and empiric Botox injection because non-relaxing sphincters might be the cause if no anatomic or pathologic abnormality is found.

In Duhamel patients, biopsy must be performed on the posterior wall because the anterior wall is the original aganglionic rectum.

Every child born with Hirschsprung's disease has 100% potential for bowel control because the continence mechanism (sphincters and anal canal) is normal, unlike anorectal malformation where associated spinal problems, poor sacrum, or poor muscles limit continence potential regardless of surgical quality.

If the sphincters are too good (non-relaxing), this is the opposite of weak sphincters seen in anorectal malformation.

Fecal incontinence in Hirschsprung's patients results from iatrogenic injury: overstretching of the sphincters or starting the transanal dissection too low and removing the dentate line.

Patients with damaged sphincters or absent dentate line do not have good continence potential and require a mechanical bowel management program with enemas from below (Peristeen) or antegrade enemas (Malone).

Sphincter quality can be assessed by digital exam or by observing whether the anus appears closed when the child is awake; a closed anus usually indicates good sphincters.

Anorectal manometry can objectively determine whether sphincters are intact.

The vast majority of Hirschsprung's patients are constipated and require stimulant laxatives (senna or bisacodyl), not stool softeners.

Adding water-soluble fiber to stimulant laxatives provides bulk to prevent watery stool (which is difficult to control) while maintaining the propulsion effect, creating one to two well-formed stools per day.

Soiling patients with intact sphincters may be withholding or have not learned to overcome their non-relaxing internal sphincter, and Botox is often required to help them achieve successful potty training.

Some Hirschsprung's patients have hypermotility (stool too frequently) rather than constipation; these patients may be inappropriately treated with senna, and stopping the senna can result in continence within two days.

Hypermotile patients can be identified by x-ray showing no stool accumulation despite frequent stooling, or by contrast study showing a non-dilated colon, whereas constipated patients have dilated colons.

Nocturnal soiling occurs because patients are totally dependent on voluntary control of the external sphincter, which they lose awareness of during sleep.

Hypermotile Hirschsprung's patients are managed with constipating diet, water-soluble fiber, and occasionally loperamide to achieve one to two formed stools per day.

Nocturnal soiling is managed by having the child attempt to stool before bed and sometimes giving a small enema before bed to keep the rectum empty for eight hours.

Malone antegrade continence enema is indicated when rectal enemas are not tolerated, Peristeen is ineffective, or the family prefers not to use the rectal route.

Malone procedures are typically performed between ages 3.5 and 8-9 years, around the time of potty training when it becomes clear that antegrade flushes will be required.

Most children should be in normal underwear (out of diapers) by age 3-4 years.