Hirschsprung Disease Flashcards
Which of the following is true concerning Hirschsprung’s disease?
A. More common in females
B. Absent ganglion cells in both the Auerbach and Meissner plexuses
C. Failure to pass meconium in the first 72 h of life
D. Best diagnosed by lower gastrointestinal (GI) contrast- enhanced study
E. Atrophy of submucosal nerve endings seen in rectal biopsy specimens
ANSWER: B
COMMENTS: Hirschsprung’s disease is a congenital abnormality wherein the normal ganglion nerves within the bowel wall have failed to migrate all the way down to the anus.
Nerves are missing or abnormally start at the anus and extend to a variable distance up the bowel.
The involved bowel does not exhibit normal motility and is contracted.
As a result, the normal bowel above this dilates, resulting in megacolon.
Hirschsprung’s disease is more common in males than in females.
The primary clinical manifestation of Hirschsprung’s disease is intestinal obstruction with failure to pass meconium in the first 48 h of life or chronic constipation in older infants and children.
Affected infants are prone to developing enterocolitis, which carries a high mortality rate if not recognized and treated promptly.
Evaluation may include contrast enema radiographs, anorectal manometry, and rectal wall biopsy.
Barium enema studies typically show a narrow low rectal segment and marked dilation above.
In newborns, the barium enema may be normal since dilation of the bowel proximal to the aganglionic segment may not have developed yet.
During anorectal manometry, the rectoanal inhibitory reflex is tested by distending the low rectum with a small balloon and observing a decrease in the anal canal resting pressure.
Absence of the rectoanal inhibitory reflex is pathognomonic for Hirschsprung’s disease.
Definitive diagnosis is based on a deep rectal biopsy, which will show submucosal hypertrophied nerve endings, absent ganglion cells in the Auerbach and Meissner plexuses, and acetylcholinesterase staining.
Full-term infants with Hirschsprung’s disease but without enterocolitis may be treated by a single-stage pull-through operation.
The remaining patients are managed mostly by a serial intestinal biopsy to determine the level of normal ganglionated intestine and a leveling colostomy acutely followed by a pull-through procedure 3 to 6 months later.
Anastomosis of the normally innervated colon to the anus is the basis of all of the three classically described procedures (Swanson, Duhamel, and Soave).
A newborn infant has failed to pass meconium by 48 h of life. The anus appears to be normally formed. An abdominal radiograph demonstrates dilated bowel loops with no air in the rectum. Which of the following tests is most likely to yield the diagnosis?
A. Upper GI study
B. Lower GI study
C. Suction rectal biopsy
D. Exploratory laparotomy
E. CT scan
ANSWER: C
COMMENTS: This baby most likely has Hirschsprung’s disease, which is the lack of ganglion cells in the myenteric and submucosal plexuses of the distal intestine.
The typical presentation is a failure to pass meconium within the first 48 h of life.
The patients may also have abdominal distention and dilated loops of bowel on radiographs.
This is the presentation for 50%–90% of all cases of Hirschsprung’s.
The differential diagnosis of this presentation includes distal intestinal atresia, meconium ileus, or meconium plug.
A suction rectal biopsy demonstrating a lack of ganglion cells is diagnostic. Lower GI can be helpful in the diagnosis and will demonstrate a transition zone from the normal intestine to the aganglionic portions.
However, a normal lower GI does not rule out Hirschsprung’s disease, as a short segment could be present and not result in the classic findings.
Additionally, the lower GI can help resolve a meconium ileus.
A less common presentation of Hirschsprung’s disease is chronic constipation in an older infant or even in an adult.
Many of these patients have a short segment involvement, and once weaned from breastfeeding, they tend to develop constipation.
In older children, a full-thickness biopsy rather than a suction rectal biopsy is needed to get an adequate sampling to make the diagnosis.
Describe Hirschsprung disease.
Hirschsprung disease (HD), characterized by the absence of enteric ganglia along a variable length of intestine, is the main genetic cause of functional intestinal obstruction. The enteric ganglia are derived from the vagal neural crest cells.
Describe the incidence and the most common sites of aganglionosis.
The prevalence of HD is approximately 1 in 5000 live births with a male to female
ratio of 1.
Presentation of HD is influenced by the length of colon (or in rare cases small bowel too) that is affected. HD can occur in the rectum and various lengths of proximal intestine.
The length correlates with illness severity and diagnostic difficulty.
The length of colon affected is variable; including the rectosigmoid colon (75% of patients), a longer segment above the sigmoid (17%), or the entire colon and variable lengths of the small intestine (8%).
Is Hirschsprung disease genetically inherited?
Between 15 and 25% of children born with HD have other congenital anomalies.
What percent of patients with Hirschsprung’s disease have other congenital anomalies?
HD occurs as an isolated trait in 70% of patients.
Familial cases of HD account for approximately 10–20% of total cases.
A newborn with an affected sibling has a 1 in 200 chance of having HD.
The most common chromosome abnormality associated with HD is Trisomy 21 which occurs in conjunction in 2–10% of HD cases.
Which diseases are associated with Hirschsprung disease?
Neural crest abnormalities, Trisomy 21, Smith-Lemili-Opitz syndrome, Waardenberg’s syndrome, Ondine’s curse Congenital Central hypoventilation syndrome, Mowat-Wilson, MEN-2A/Familial Medullary Thyroid Cancer, MEN-2B [1].
In what layer of the bowel are ganglion cells missing with Hirschsprung disease?
There is an absence of ganglion cells in the intramuscular plexus and the submucosal plexsus.
The internal sphincter is also dysfunctional; there is an absence of the rectoanal inhibitory reflex (RAIR).
What is the differential diagnosis of Hirschsprung disease?
Malrotation with volvulous, intestinal atresias or stenoses, duodenal obstruction, meconium ileus, meconium plug syndrome, hypothyroidism, anorectal malformation, constipation, milk protein allergy, opoid affect transmitted from the mother, angnesium sulfate toxicity from maternal labor.
What is the presentation of HD and how is it diagnosed?
Most infants present in the first 24-hours after birth with delayed passage of meconium and associated abdominal distension, constipation, and bilious emesis.
Digital examination of the anus may result in explosive passage of meconium/ stool and gas.
The diagnosis is suspected with plain abdominal films demonstrating a colon distended with gas and an nondilated rectum.
A contrast enema usually identifies a transition zone.
Contrast retained in the colon great than 24 hours and on a post evacuation film are typical.
The rectosigmoid ratio is utilized by radiologists and is calculated from the contrast enema.
It divides the widest diameter of the rectum by the widest diameter of the sigmoid loop when the colon is fully distended by contrast media.
The normal rectosigmoid index is >1, and in HD it is <1.
A suction rectal biopsy or full thickness rectal biopsy for permanent pathology confirms the diagnosis, and both the absence of ganglion cells and the presence of hypertrophic nerves (greater than 40 microns) must be observed.
In Hirschprung Disease, which should be used as first line therapy in the treatment of Hirschsprung associated enterocolitis (HAEC)?
Irrigations and metronidazole.
The reported incidence of HAEC varies widely (due largely to a broad definition) ranging from 6 to 60% prior to definitive pull-through surgery and from 25–37% following surgery [2].
The principles of treatment are to decompress the colon/intestine, perform rectal irrigations, initiate broad-spectrum antibiotics, and correct dehydration and electrolyte imbalances.
Prompt rectal irrigations should be initiated immediately in the emergency department, neonatal intensive care unit, or clinic.
A rectal irrigation is performed with a large bore soft silicone catheter, 20-French for children less than 1 year of age, or a 24-French for children greater than 1 year of age.
Using room temperature or warm saline, 10–20 mL of saline should be instilled into the colon via the catheter to allow gas and stool to empty through the catheter.
This process should be repeated with aliquots of 10–20 mL of saline until the effluent runs clear.
What is the best, most reliable intervention to perform for a sick child with enterocolitis if irrigations are not working?
Leveling colostomy or an ileostomy. Both are correct answers depending on the clinical circumstances.
In obtaining a suction rectal biopsy in a neonatal infant, what are important technical components of the biopsy for the diagnosis of Hirschsprung disease?
A diagnostic biopsy should be performed 1 cm above the dentate line.
The biopsy should be performed at this level and not distal to it as the epithelium is different than that visualized in the large intestine- squamous epithelial cells vs. columnar epithelial cells.
Mucosa and submucosa should be included in the tissue sampled.
At the time of the surgical procedure, when you do a biopsy to determine the colonic level at which to do the pull-through, you should:
Take a full thickness biopsy (which includes submucosa) either laparoscopic, tran- sumbilical, or open in the part of the colon above the visualized transition zone.
The reason for this biopsy technique is to avoid the potential pitfall of sampling only the seromuscular layer which could have ganglion cells while submucosal layer could have hypertrophic nerves.
What size nerve is considered hypertrophic?
Greater than 40 microns.
During the pull-through, where is the ideal location to begin the transanal dissection?
0.5–1.0 cm above the dentate line.
Starting the trans-anal dissection too low in the anal canal (too distal) results in loss of the dentate line and will negatively impact future continence.
Describe the operative differences in the three most common types of pull-through operations performed for Hirschsprung disease.
Swenson: Full thickness rectosigmoid dissection with end-to-end anastomosis.
Soave: originally performed as a way to avoid the risks of injury to pelvic structures inherent in the Swenson dissection plane (which occurred when the surgeon was in the incorrect surgical plane). Consists of removing the mucosa and submucosa of the rectum and placing the pull-through bowel within a “cuff” of aganglionic muscle.
Duhamel: The aganglionic colon is resected to the rectum and the normal proximal bowel is brought retrorectally. The ganglionated colon and rectum are brought together in a side-to side anastomosis.
Laparoscopy as part of a pull-through for Hirschsprung disease is helpful for:
Mobilization of the splenic flexure, ligation of the inferior mesenteric and sigmoidal arcades, mobilization of the left colon off the retroperitoneum, and distal dissection of rectum into the pelvis.
In the Soave procedure, what complication can result by having too long of a cuff or an incised cuff that has fused back together or rolled up?
An obstructing cuff, which surrounds the pull-through, and physiologically causes external compression.
What goals should be achieved prior to the performance of a pull- through on a child with total colonic Hirschsprung Disease to reduce the incidence of perineal excoriation?
HD may extend to the small intestine (total colonic type)and males and females are equally affected.
Imaging may demonstrate a normal or small caliber colon. Prior to ileo-anal or ileo-Duhamel pull-through the patient must demonstrate the ability to have thickened ileostomy output as liquid stools are difficult to control, good nutrition and growth (check urinary sodium—should be >30 mmol/L), and the availability of products to treat perineal rash.
Timing for these milestones is between 6–12 months of age.
What are early complications of a pull-through for Hirschsprung disease?
Anastomotic leak, stricture, intestinal obstruction, wound infection, and enterocolitis.
In a post pull-through Hirschsprung patient with recurrent enterocolitis, what potential problems with the pull-through can cause obstructive symptoms?
A stricture at the anastomosis, obstructing Soave cuff, twist of the pull-through, Duhamel spur, or dilated pouch, persistently dilated segment of bowel, retained transition zone, or aganglionic pull-through.
In Hirschsprung Disease, the most likely cause of postoperative fecal incontinence is:
Iatrogenic, related to the loss of the dentate line, overstretching of the sphincters, or both [3].
A Hirschsprung patient at the age of 12 is soiling. Work-up for this patient should include:
Contrast enema, digital and visual exam of the anal canal and dentate line under anesthesia, and anorectal manometry.
Anal manometry (AMAN) is performed for fecal soiling demonstrating no recto anal inhibitory reflex (RAIR) and low resting pressures. Given these findings on AMAN, what likely findings will be visualized on operative visualization of anal canal and dentate line under anesthesia?
Injured sphincters without tone or complete loss of the dentate line.
What finding on anorectal manometry suggests a diagnosis of Hirschsprung Disease?
Absence of the recto anal inhibitory reflex (RAIR).
The physiology of voluntary bowel evacuation relies on the RAIR.
The normal internal sphincter relaxation in response to distention of the rectum is absent in Hirschsprung disease.
When a bolus of fecal material is delivered to the rectum, increased rectal pressure and distension causes transient relaxation of the internal anal sphincter, allowing a small sample of the rectal contents to come in contact with the sensory afferent somatic nerves innervating the anorectum.
Then the individual can choose if and when to tighten the external (voluntary) sphincters.
What are some different histologic stains utilized to assist in diagnosing Hirschsprung disease?
H + E or hematoxylin and eosin—one of the principal stains in histology.
Acetylcholinesterase (AChE)—only good for the distal colon.
Calretinin—stains thin nerve fibrils (neurites) and can add diagnostic value to
specimens with inadequate submucosa or rarely seen ganglion cells.
Is the content of acetylcholinesterase increased or decreased in the nerve fibers of the lamina propria and muscularis mucosa in patients with Hirschsprung disease?
It is significantly increased, and is one of the essential points of diagnosis in some institutions when assessing a rectal biopsy for HD.
However, it is useful only in rectal biopsies and in biopsies of the left colon because there usually is no acetylcholinesterase activity proximal to the splenic flexure.
Should the evaluation for ganglion cells in the appendix be utilized for pathologic diagnosis of Hirschsprung’s disease?
The appendix should not be utilized to determine whether there is Hirschsprung disease as many normal appendices have no ganglion cells [4].
Define functional constipation? What is the most current indication for surgical management in children with constipation?
Constipation is defined as infrequent bowel movements (2 or fewer per week) that are painful, or large in caliber stools that require excessive straining.
The Rome III criteria for constipation are utilized in infants and children up to 4 years of age.
This includes one month of at least 2 of the following: 2 or fewer defecations per week, at least 1 episode per week of incontinence after acquiring toileting skills, history of excessive stool retention, history of painful or hard bowel movements, presence of a large fecal mass in the rectum, history of large diameter stools that may obstruct the toilet.
Accompanying symptoms include irritability with decreased appetite and/or early satiety.
The accompanying symptoms disappear immediately following passage of a large stool.
What imaging and workup aids in understanding functional constipation and potentially rules out other causes of constipation?
A thorough understanding of which laxatives or enemas have been utilized and to what effect, as well as anorectal examination, contrast enema, anorectal manometry, and colonic motility testing.
Colonic motility testing (sitzmarkers, radionuclides, or colonic manometry) is reserved only for those patients who have failed medical management (laxative or enema therapy).
What is the most common indication for surgical management in children with constipation?
The most common indication for surgical intervention in a child with functional constipation is for one who has failed medical management; high dose laxatives do not work or cause intolerable cramping and enemas do not empty the colon or are not tolerated.
For these patients, anal manometry (AMAN) is performed to see if Botox or pelvic floor biofeedback is indicated and colonic manometry (CMAN) is performed to determine whether motility is normal, diffusely abnormal or seg- mentally (usually the sigmoid) abnormal.
Based on the motility testing an antegrade option can be offered which is usually successful, but if flushes do not work a colonic resection may be required.
How is functional constipation treated?
Through a combined multidisciplinary approach with the implementation of laxatives, dietary modifications, defecation trials, psychosocial support and appropriate testing.
Psychosocial counseling often benefits the patient and family as part of a multimodality management.
What are some surgical options for children with medically refractory functional constipation?
A number of surgical procedures have been proposed that include anal and pelvic floor procedures (such as Botox and biofeedback training), antegrade continence enema procedures (Malone antegrade continence enemas or cecostomy), colonic resections and sacral nerve stimulation (SNS) [5].
What colonic manometry/colonic motility test finding is consistent with poor colonic motility?
The absence of high amplitude propagating contractions (HAPC) in response to a stimulant medication.
Which patients are most likely to have a good response to antegrade enema flushes?
Children with poor motility that is limited to the sigmoid as well as children with normal colon motility.
What percentage of neurologically normal children with fecal incontinence have functional constipation as an underlying disorder?
> 95% of children.
A barium enema shows the following findings on Hirschsprung disease, except:
A. Spastic (narrow) distal intestine with dilated proximal intestine.
B. Transitional zone.
C. Presacral space.
D. Right-sided sigmoid colon
E. Increased recto-sigmoid index.
E. Increased recto-sigmoid index.
What is not true about the surgical procedures of Hirschsprung disease?
A. In Duhamel procédure, there is retro-rectal pullthrough.
B. In Swenson procedure, there is resection and anastomosis.
C. In Soave procedure, there is endorectal pullthrough.
D. Martin’s modification is for ultra-short segment Hirschsprung disease.
E. Aganglionic patch is used in Kimura’s procedure.
D. Martin’s modification is for ultra-short segment Hirschsprung disease.
What is true about the full thickness rectal biopsy for Hirschsprung disease?
A. It is an established manner of diagnosis.
B. It is taken from below the dentate line.
C. It is taken from anterior rectal wall.
D. Rectal defect is left open.
E. Stay suture helps in taken biopsy, should be avoided.
A. It is an established manner of diagnosis.
Which of the following is false for leveling colostomy for Hirschsprung disease?
A. You should determine the ganglionic level at the time of colostomy.
B. It facilitâtes subsequent pullthrough.
C. It allows proximal bowel to grow, which will stretch the mesentery and simply subsequent pullthrough procedure.
D. All above.
E. None of the above.
E. None of the above.
Which of the following is not true regarding colostomy for Hirschsprung disease?
A. It is easy to identify the transitional zone in neonate.
B. On the frozen section, hypertrophy of the nerve bundle, despite the presence of ganglion, suggests that one is still in the transition zone.
C. Loop colostomy is created at one of the normal biopsy sites.
D. Aganglionosis of appendix indicates total colonic aganglionosis.
E. Stoma usually starts to act within 24hours.
A. It is easy to identify the transitional zone in neonate.
Regarding rectal suction biopsy, for Hirschsprung disease, which of the following is false?
A. It is a painless procedure, provided it is taken at least 2.5cm above the anal verge in neonates and 3.5cm in older children.
B. Pressure usually used is above 300mmHg.
C. Specimen is usually taken from anterior wall.
D. Specimen is usually 3mm long and 1mm wide.
E. Inadequate specimen is a common problem.
C. Specimen is usually taken from anterior wall.
Causes of constipation in children include all except:
A. Anteriorly placed anus
B. Anal stenosis
C. Anal fissure
D. Cystic fibrosis
E. Hyperthyroidism
E. Hyperthyroidism
Regarding types of Hirschsprung disease according to involved segments, which of the following statements is false?
A. In short segment disease, rectal and distal sigmoid colonic involvement only occurs.
B. Long segment typically extends to splenic flexure/transverse colon
C. In total colonic aganglionosis, occasional there is extension of aganglionosis into small bowel
D. Ultrashort segment disease is 3-4cm of internal anal sphincter only
E. All of the above are false.
E
Statements A, B, C, D are true.
—
The ultrashort segment HD, which is a rare condition, is characterized by an aganglionic segment of 1 to 3 cm long and normal acetylcholinesterase (AChE) activity in the lamina propria and increased AChE activity in the muscularis mucosae. Many patients who are considered to have ultrashort HD on abnormal anorectal manometric findings show presence of ganglion cells and normal acetylcholinesterase (AChE) activity in suction rectal biopsies.
Coran
—
Some surgeons use this term to describe children with normal ganglion cells on rectal biopsy, but with absence of the RAIR, which is synonymous with the definition of internal sphincter achalasia. We prefer to reserve this term for children who have a documented aganglionic segment of <3–4 cm.
In children with this condition, the findings of hypertrophic nerves and abnormal cholinesterase staining may be absent.
The treatment of ultra-short segment HD is controversial. Some authors advocate simple anal sphincter myectomy, whereas others prefer excision of the aganglionic segment with a pull-through.
H&A
Pathologic histological findings in Hirschsprung disease?
1) Absence of ganglion cells in the submucosal and myenteric plexus
2) Hypertrophied nerve trunks
3) Stains: H&E, characteristic pattern of increased acetylcholinesterase in submucosa and mucosa, absent calretinin
What are criteria for diagnosing HAEC?
The classic manifestations of HAEC include abdominal distention, fever, and diarrhea. However, there is a broad clinical spectrum with which children present, and other signs or symptoms may include vomiting, rectal bleeding, lethargy, loose stools, and obstipation.
Of note, these symptoms are non-specific and this likely contributes to the highly variable incidence of HAEC reported in the literature.
Mild cases, manifesting with only fever, mild distension, and diarrhea, present just like viral gastroenteritis, which is very common in young children.
Given the difficulty in making a definitive diagnosis, combined with the high morbidity associated with a delayed or missed diagnosis, most pediatric surgeons err on the side of assigning the diagnosis of HAEC and presumptively treating suspected cases.
In general, assuming the child has HAEC and initiating treatment is preferable to delaying the diagnosis and having the child present later with more advanced disease.
In an attempt to address the difficulty in establishing the diagnosis of HAEC, a group of 27 gastroenterologists and surgeons participated in a Delphi process, starting with 38 features (history, patient characteristics, physical exam signs, laboratory findings, radiology findings, pathology findings) and iteratively refining this list to 16 items to develop a HAEC score.
The resulting tool, although useful for standardizing outcome measures in research studies, is cumbersome for routine use, has not been validated for clinical application, and has not been widely adopted in the clinical setting. More recently, another group described a “clinical grade” for HAEC for use in a prospective trial.
This system grades the degree of diarrhea, abdominal distention and systemic manifestations into mild, moderate and severe in order to assign an overall clinical grade. Following a staging system similar to that described by Bell for necrotizing enterocolitis (NEC), and incorporating elements of published HAEC grading systems and clinical experience, we have categorized the clinical suspicion and severity of HAEC into three grades based on history, physical examination, and imaging studies [Figure 1].
The goal of this approach is to create a standardized, clinically relevant, and easy to use system that can be universally adopted to allow a consistent approach to the diagnosis and treatment of HAEC. In general, presence of higher grade findings should prompt providers to err toward assigning the higher grade and initiating the corresponding treatment.
Guideline for the diagnosis and grading of HAEC from grade I (possible HAEC) through grade III (severe HAEC) based on clinical history, physical examination, and radiographic findings. This figure is not intended as a scoring system, but rather a decision-support tool to ensure that all of the relevant history, examination and radiographic findings are considered. In general, presence of higher grade findings should prompt providers to assign the higher grade. (HAEC: Hirschsprung-associated enterocolitis, DRE: digital rectal examination).
PubMed Central
What is the management of HAEC?
Since the cause of HAEC is generally unknown, treatment remains empiric and directed toward alleviating acute symptoms as well as managing the factors that may contribute to pathogenesis. Treatment is based on the severity of the clinical presentation, as detailed in Figure 2.
In cases classified as Grade I (possible HAEC), outpatient management can typically be employed. Treatment in these cases should include oral metronidazole and oral hydration with Pedialyte or other electrolyte-rich solution. Rectal irrigations to wash retained stool out of the colon should be considered in children who have abdominal distension or who are not evacuating fully. They may also be used as a trial to see if irrigation leads to symptomatic improvement. Close monitoring is necessary in case symptoms progress to a higher grade of disease.
In more severe cases, Grade II (Definite HAEC), inpatient admission is often necessary. These children are managed with either clear liquids or nothing by mouth, intravenous fluids, and nasogastric decompression if there is significant abdominal distension. Rectal irrigations are very effective, helping to resolve fecal stasis. Metronidazole (oral or parenteral) is used to treat anaerobes, including Clostridium difficile, which has been associated with HAEC. In addition to metronidazole, broad spectrum intravenous antibiotic coverage using either the combination of ampicillin and gentamicin, or piperacillin/tazobactam, or aztreonam (in the case of penicillin allergy) should be considered.
Children with findings consistent with Grade III (severe) HAEC, particularly with shock, may require admission to an intensive care unit. Bowel rest, intravenous fluid resuscitation, rectal irrigations, and broad-spectrum antibiotics (including metronidazole) are required. Patients who fail to improve may benefit from proximal enteric diversion. Rarely, pneumoperitoneum can occur, which would prompt immediate surgical intervention.
PubMed Central
What are principles for Hegar dilatation postoperatively?
Dilating Your Child’s New Anus
You will start by dilating your child’s new anus two times each day – one time in the morning and one time in the evening.
Put your child on their back with the knees pulled up towards the chest.
Lubricate the dilator. Put the dilator in the anus and keep in place for 30 seconds.
Remove it and put it in again for 30 seconds.
It is best to not dilate your child right after they eat a meal.
Changing the Size of the Dilator
Every week, you will increase the size of the dilator, using the next larger size. Continue to dilate your child’s anus two times a day until you get to the goal size set by the doctor.
Tips about Dilatations
The dilatations may cause some discomfort for your child as you get closer to the last 2-3 sizes. You may feel that you want to stop dilating your child’s anus every day because of the slight discomfort, but it is very important to keep dilating two times a day.
For best comfort, be sure to lubricate the dilator well.
Lubricate and insert a smaller dilator, just before you insert the right size dilator.
Position your child without movement.
If the dilation plan is not followed right, there is risk of scarring during the healing process. This can narrow the anus. If this happens, your child may need to have more surgery to correct the problem.
For Children with a Colostomy
If your child had a colostomy before this surgery, the colostomy may be closed when the goal size of the anus is reached. After the colostomy is closed, you will still need to dilate your child’s anus until the dilator goes in easily with no discomfort. This will likely be about 3-4 weeks after you get to the last size dilator.
Cincinnati Children’s
How are obstructive symptoms evaluated and managed post pullthrough?
There are a range of obstructive symptoms that can be seen after a pull-through. Abdominal distension, bloating, vomiting, or ongoing severe constipation may be present immediately after surgery or may develop later after an initial period of normal bowel function.
There are five major reasons for persistent obstructive symptoms following a pull-through:
mechanical obstruction,
recurrent or acquired aganglionosis,
disordered motility in the proximal colon or small bowel,
internal sphincter achalasia, or functional megacolon caused by stool-holding behavior.
The clinician will have much greater success in managing these difficult patients if an organized approach to this problem is taken. One proposed algorithm is shown in Figure 101-9.
1) Mechanical Obstruction
The most common cause of mechanical obstruction after a pull-through is a stricture, which usually occurs after a Swenson or Soave procedure.
Patients undergoing a Duhamel procedure may have a retained “spur” consisting of the anterior aganglionic bowel, which may fill with stool and obstruct the pulled-through bowel.
In other cases, there may be obstruction secondary to a twist in the pulled-through bowel, or narrowing due to a long muscular cuff in children who have had a Soave procedure.
Obstruction can be identified using a combination of digital rectal examination and a barium enema.
Initial management of anastomotic stricture consists of repeated dilatation using a finger, dilator, or radially dilating balloon. Some authors have advocated innovative techniques for recalcitrant strictures including antegrade dilatation over a string using Tucker dilators and the use of intralesional steroid.
In some cases the stricture cannot be successfully dilated, and revision of the pull-through is necessary. This is best done using the Duhamel technique, although other operations have also been advocated.
Duhamel spurs can be resected from above or managed by extending the staple line from below, with or without laparoscopic visualization.
Twisted pullthroughs and narrow muscular cuffs usually require surgical intervention, typically a repeat pull-through. In some cases, a muscular cuff can be divided laparoscopically without having to re-do the entire pull-through.
2) Persistent or Acquired Aganglionosis
This rare problem may be due to pathologist error, a transition zone pull-through, or ganglion cell loss after a pull-through. Repeat rectal biopsy, above the previous anastomosis (it must be posterior in the case of an initial Duhamel procedure), should be done to determine whether there are normal ganglion cells present in all patients with persistent obstructive symptoms after surgery.
The pathology from the original operation should be reviewed to ensure that there was normal innervation at the proximal margin, and in some cases further sections should be done circumferentially from the resection margin because the transition zone is often asymmetrical in children with Hirschsprung disease.
The best treatment for persistent or acquired aganglionosis in most cases is a repeat pull-through, which can be done using either a Soave or Duhamel approach.
3) Motility Disorder
Children with Hirschsprung disease often have associated motility disorders including an increased incidence of gastroesophageal reflux and delayed gastric emptying, small bowel dysmotility, and disordered colonic motility. Some cases are more focal, usually involving the left colon. In some cases the disordered motility may be associated with histological abnormalities such as intestinal neuronal dysplasia (discussed in greater detail later).
In children who have been shown not to have a mechanical obstruction and who have normal ganglion cells on rectal biopsy, investigations for motility disorders should be undertaken. This can include a radiologic shape study, radionuclide colon transit study, colonic manometry, and laparoscopic biopsies looking for evidence of intestinal neuronal dysplasia. If a focal abnormality is found, consideration should be given to resection and repeat pull-through using normal bowel. If the abnormality is diffuse, the appropriate treatment is bowel management and the use of prokinetic agents. Some children with particularly dysmotile colon will benefit from placement of a cecostomy for antegrade colonic enemas.
4) Internal Sphincter Achalasia
This term refers to the lack of a normal RAIR that is present in all children with Hirschsprung disease (as described earlier in “Diagnosis”). It is unclear why only some children develop obstructive symptoms from this nonrelaxation, while others function normally in the postoperative period. It is also unclear why most children eventually “grow out” of this problem over time, usually by the age of 5 years. Internal sphincter achalasia is a diagnosis of exclusion, which is made after ruling out mechanical obstruction, aganglionosis, and dysmotility. The diagnosis can be confirmed by demonstrating a clinical response to intrasphincteric botulinum toxin. However, the response to botulinum toxin is not related to the absolute value of the internal anal sphincter pressure (i.e., patients with a higher resting pressure are not necessarily more likely to benefit from botulinum toxin).
The standard treatment of internal sphincter achalasia has been internal sphincterotomy or myectomy, but because this problem tends to resolve on its own in most children and there is concern about sphincter-cutting operations exacerbating future soiling issues, we prefer to use “chemical sphincterotomy” with intrasphincteric botulinum toxin. In many cases repeated injection of botulinum toxin or applications of nitroglycerine paste or topical nifedipine are necessary while waiting for resolution of the problem.
5) Functional Megacolon
Functional megacolon is the result of stool-holding behavior, a common cause of constipation that some authors claim affects up to half of normal children at some time during their first few years of life. This condition is probably even more common in children with Hirschsprung disease because of their predisposition to constipation, which leads to hard painful stools, withholding behavior, and a resulting vicious cycle. The treatment for this problem is a bowel management regimen consisting of laxatives, enemas, and behavior modification including support for the child and family. In some severe cases of obstructive symptoms, the child may be best served by use of a cecostomy and administration of antegrade enemas, or even by the creation of a proximal stoma. In many cases the cecostomy or stoma can ultimately be reversed when the child reaches adolescence.
Coran
What are the causes of fecal soiling post pullthrough?
There are three broad causes of soiling after a pull-through:
abnormal sphincter function,
abnormal sensation, or
“pseudo-incontinence” related to abnormal rectal function or obstipation.
Abnormal sphincter function may be due to sphincter injury during the pull-through or to a previous myectomy or sphincterotomy and can usually be identified using anorectal manometry.
Two forms of abnormal sensation exist. The first is lack of sensation of a full rectum, which is also identifiable using anorectal manometry by expanding a balloon in the rectum and asking the child to state when he can feel it.
The other type of sensation that may be abnormal is the ability to detect the difference between gas and stool, which is dependent on intact transitional epithelium in the anal canal. This sensation may be impaired if the anastomosis is done too low and the transitional epithelium is damaged. This problem is usually evident on simple physical examination.
Neither sphincter weakness nor abnormal sensation is amenable to a surgical solution, and most of these children are best managed using a bowel routine that may include a constipating diet, rectal enemas, or antegrade enemas through a cecostomy.
Biofeedback training has been advocated, especially for those children with sphincter weakness. In some cases the child is best served by a colostomy.
If both the sphincter and sensation are intact, the most common cause of soiling after a pull-through is “pseudoincontinence.” Some patients have severe obstipation with a massively distended rectum and develop overflow of liquid stool around the fecal mass. Others simply leak small amounts of stool through the day, creating “skid marks” in the underwear on a constant basis. Other children suffer from hyperperistalsis of the pulled-through bowel, which results in inability of the anal sphincter to achieve control despite normal sphincter function.
Successful management depends on a clear understanding of the underlying basis for the soiling, which requires a clear history and physical examination, as well as investigations such as abdominal radiograph, barium enema, anorectal manometry, and in some cases colonic manometry. Children with severe constipation will benefit from laxative therapy. However, if the sphincter or sensation, or both, are inadequate, passive laxatives such as lactulose or PEG 3300 will make the problem worse and the child should instead be treated with stimulant laxatives such as senna or enemas. On the other hand, children with stool-holding behavior who have a normal sphincter and sensation will often experience exacerbation of the behavioral problem by rectal enemas or any other kind of anal manipulation.
Children without constipation who have hyperperistalsis of the pulled-through bowel or abnormal sphincter function or sensation will benefit from a constipating diet and medications such as loperamide.
Children with slow transit constipation or stool-holding behavior, on the other hand, will benefit from a high-fiber diet and passive laxative therapy.
The treatment of soiling must be based on a clear understanding of the child’s underlying problem.
Coran
How is enterocolitis managed post pullthrough?
Enterocolitis may be present both before and after surgical correction of the disease, and it can be severe or life threatening.
HAEC is more common in children diagnosed at a younger age, those with longer segment disease, and those with trisomy 21.
The clinical features of HAEC are generally agreed on and include fever, abdominal distention, diarrhea, elevated white blood cell count, and evidence of intestinal edema on abdominal radiograph.
Because there is overlap between HAEC and other conditions such as obstructive symptoms and gastroenteritis, there has been confusion in the literature as to the exact definition and the true incidence of the condition.
A recently developed HAEC score may be useful in the future in both the clinical setting and in research into this area (Table 101-4).
The treatment of postoperative HAEC involves nasogastric drainage, intravenous fluids, broad-spectrum antibiotics, and decompression of the rectum and colon using rectal stimulation or irrigations. The risk of HAEC can be minimized by using preventive measures such as routine irrigations or chronic administration of metronidazole or probiotic agents, particularly in those who are thought to be at higher risk for this complication on the basis of clinical or histologic grounds.
Because enterocolitis is the most common cause of death in children with Hirschsprung disease and can occur postoperatively even in children who did not have it preoperatively, it is extremely important that the surgeon educate the family about the risk of this complication and urge early return to the hospital if the child should develop any concerning symptoms.
Coran
How do you diagnose intestinal neuronal dysplasia?
DIAGNOSTIC CRITERIA
Since the first description in 1971, most controversy surrounding IND has been regarding which histologic diagnostic criteria are required for definitive diagnosis. The presently recognized diagnostic criteria, previously reported by our group and supported by others, are hyperganglionosis and giant ganglia, in addition to the presence of at least one of the following on suction rectal biopsy: ectopic ganglia in the lamina propria and increased AChE-positive nerve fibers around submucosal blood vessels and in the lamina propria. However, Lumb and Moore believe that giant ganglia can be a normal feature in normal bowel, having identified them in segments of adult bowel removed during surgery for colorectal carcinoma. To overcome the confusion in diagnostic criteria, Borchard and colleagues produced guidelines for identifying IND in mucosal rectal biopsies.
These comprised two obligatory criteria (hyperplasia of the submucous plexus and an increase in AChE-positive nerve fibers around submucosal blood vessels) and two additional criteria (neuronal heterotopia and increased AChE activity in the lamina propria).
In our experience, hyperganglionosis and giant ganglia are the most important features for the diagnosis of IND in suction rectal biopsies, except in the newborn, when hyperganglionosis is a normal finding.
DIAGNOSIS
Suction rectal biopsy is the principal method for the diagnosis of disorders of intestinal innervation. It is necessary to include a sufficient amount of submucosa in the suction biopsy specimens. Traditionally, hematoxylin and eosin and AChE histochemical staining (Figs. 102-1 and 102-2) in suction rectal biopsy specimens have provided the basis for the diagnostic evaluation of IND. However, there has been discussion about whether AChE histochemistry is sufficient for the accurate diagnosis of IND and other additional staining techniques have been proposed.
Meier-Ruge and colleagues suggest lactate dehydrogenase histochemistry.
In my laboratory, neuronal markers currently being used are reduced nicotinamide-adenine dinucleotide phosphate (NADPH) diaphorase histochemistry and immunohistochemistry using antibodies raised against neural cell adhesion molecule, protein gene product 9.5 (PGP9.5), S-100, peripherin, and synaptophysin.
Ganglion-cell counting can be difficult. Standard immunohistochemical techniques, using antibodies raised against neuron-specific enolase or PGP9.5, which are commonly used to display the enteric nervous system, are less suitable for cell counting because they stain not only the cell bodies but also the axonal processes. Cuprolinic blue staining has been proposed as the method that stains the largest number of ganglion cells. Furthermore, this method stains only the cell bodies and not the axons, which makes it relatively easy to distinguish the individual cells.
Barium enema in IND does not show any specific radiologic features other than rectosigmoid distention. Similarly, anorectal manometry may show the rectosphincteric reflex to be present, absent, or atypical.
CORRELATION BETWEEN HISTOLOGIC FINDINGS AND CLINICAL SYMPTOMS
Several investigators have raised doubts about the existence of IND as a distinct histopathologic entity. One reason for this has been the weak correlation found between the severity of clinical symptoms and the histologic findings. It has been suggested that the histologic findings of IND can be a part of normal development or secondary to prolonged constipation. Recently, Montedonico and colleagues correlated specific clinical, radiologic, and manometric findings with the severity of histopathologic findings in 44 patients with IND treated at their institution over 20 years. They classified IND according to the severity of histochemical alteration into two groups: mild IND and severe IND. The criteria used for the diagnosis of severe IND included hyperplasia of the submucous plexus, giant ganglia with more than seven ganglion cells, increased AChE activity in the lamina propria or surrounding submucosal blood vessels, and heterotopic neuronal cells in the lamina propria. Any biopsy specimen that showed giant ganglia of the submucous plexus with only one of the other elements was considered mild IND. According to their results, the characteristic clinical pattern of severe IND can be found in infants younger than 1 year old with a history of constipation and abdominal distention, thus mimicking HD, with absence of internal sphincter relaxation in anorectal manometry but who have a normal barium enema. The median age at presentation of severe IND was 5 months, and similar results have been reported in other series. These authors found a correlation between the histologic severity of IND and the clinical symptoms, suggesting that IND is a distinct entity. Although many cases of IND are clinically indistinguishable from HD, barium enema findings in IND are often equivocal or show slight to moderate rectosigmoid distention but lack the typical narrow segment of aganglionosis.
Coran
How do you diagnose isolated hypoganglionosis?
Isolated hypoganglionosis (IH) has been classified as a “hypogenetic type” of intestinal innervation disorders.
Clinically, IH resembles classical HD: Patients present with severe constipation or pseudo-obstruction.
Due to the fact that IH is one of the rarest subtypes of intestinal innervation disorders, accounting for only 5% of all cases, the number of reported cases in the literature is limited. Dingemann and Puri recently reviewed 92 patients with IH reported in the English literature between 1978 and 2008 and critically analyzed the current state of the epidemiologic, diagnostic, and therapeutic features of this rare neuronal intestinal disorder.
EPIDEMIOLOGY
In the reported review the overall male-to-female ratio of IH was 3:1. This is similar to the overall male-to-female ratio of HD, which is commonly considered to be 4:1. Although 29 (32%) patients were diagnosed in the newborn period, the median age at diagnosis of the reported patients with IH was 4.85 years. This is due to the fact that, in some patients, diagnosis was made as late as the age of 17 years. This differs significantly from HD. Although late diagnosis is also possible in HD, more than 90.6% of patients are diagnosed in the newborn period. This late diagnosis of IH might reflect the difficulties in diagnosing IH in rectal suction biopsies but also the rareness of the disease.
CLINICAL PRESENTATION
Even though the median age at diagnosis is significantly higher in patients with IH than in those with HD, the symptoms of IH resemble classical aganglionosis. The symptoms reported in all IH included intractable constipation, ileus, and enterocolitis. As in HD, enterocolitis of the newborn remains the most serious complication of IH, as 6 of the 7 reported IH related deaths were neonates with enterocolitis.
HISTOPATHOLOGIC APPROACH
The diagnosis of IH by means of rectal suction biopsy is difficult. As recommended by the interdisciplinary consensus conference, a full-thickness bowel is essential for the diagnosis of IH. Besides standard hematoxylin and eosin staining, histochemical evaluation of AChE was performed by 91% of the authors in the review by Dingemann and Puri to visualize the characteristic changes for IH such as low mucosal activity of AChE, deficiency of nerve cells in the myenteric plexuses, and hypertrophy of muscularis mucosae and circular muscle layers.
Morphometric measurements in IH using AChE staining, as suggested by Meier-Ruge and colleagues, represent one of the cornerstones of diagnostic criteria for the disease. It has been shown that plexus area and nerve cell number are dramatically decreased, and the distance between ganglia is almost doubled.
Several additional neuronal markers have been used to diagnose IH. Rolle and colleagues used NADPH diaphorase staining, which not only allows one to characterize the nitrergic innervation of the muscle but also differentiates mature fully developed ganglia from the immature ganglia in IH.
Coran
What is megacystis-microcolon-intestinal hypoperistalsis syndrome?
MEGACYSTIS-MICROCOLON-INTESTINAL HYPOPERISTALSIS SYNDROME
MMIHS is a rare congenital and generally fatal cause of functional intestinal obstruction in the newborn.
This syndrome is characterized by abdominal distension caused by a distended nonobstructed urinary bladder, microcolon, and decreased or absent intestinal peristalsis.
Usually incomplete intestinal rotation and shortened small bowel are associated.
PATHOGENESIS
MMIHS was first described in1976 by Berdon and colleagues and, to date, 182 cases have been reported in the literature.
The etiology of this syndrome remains unclear. Several hypotheses have been proposed to explain the pathogenesis of MMIHS: genetic, neurogenic, myogenic, and hormonal origin.
Histologic studies of the myenteric and submucosal plexuses of the bowel of MMIHS patients have found normal ganglion cells in the majority of the patients, decreased in some, hyperganglionosis, and giant ganglia in others.
Recently, Piotrowska and colleagues 34 reported absence of interstitial cells of Cajal (ICCs) in the bowel and urinary bladder of patients with MMIHS. ICCs are pacemaker cells that assist active propagation of electrical events and neurotransmission, and their absence may result in hypoperistalsis and voiding dysfunction in MMIHS.
Puri and colleagues showed, in 1983, vacuolar degenerative changes in the smooth muscle cells (SMCs) with abundant connective tissue between muscle cells in the bowel and bladder of patients with MMIHS and suggested that a degenerative disease of smooth muscle cells could be the cause of this syndrome.
Several subsequent reports have confirmed evidence of intestinal myopathy in MMIHS. Other investigators have reported absence or marked reduction in a-smooth muscle actin and other contractile and cytoskeletal proteins in the smooth muscle layers of MMIHS bowel.
Contractile and cytoskeletal proteins are important structural and functional components of SMCs and play a vital role in the interaction of the filaments in smooth muscle contraction.
Coran
How is megacystis-microcolon-intestinal hypoperistalsis syndrome diagnosed?
PRENATAL DIAGNOSIS
Puri and Shinkai reviewed 182 cases of MMIHS reported in the literature. In 54 cases ultrasound findings associated with MMIHS were described.
The most frequent finding was enlarged bladder (88%), with hydronephrosis seen in 31 patients (57%).
Normal amniotic fluid volume was revealed in 32 cases (59%), increased volume occurred in 18 (33%), and volume decreased in 4 (7%).
In three cases (5%) abdominal distention caused by dilated stomach was detected.
Three cases of oligohydramnios during the second and early third trimesters were reported, probably related to the functional bladder obstruction.
Serial obstetrical ultrasonography showed that the earliest finding in MMIHS is enlarged bladder, detectable from 16 weeks of gestational age. A later finding is hydronephrosis, caused by the functional obstruction of the bladder. Usually polyhydramnios develops late, appearing during the third trimester.
CLINICAL PRESENTATION
Of the 182 cases reported in the literature, sex of the patient was mentioned in 149 patients. Ninety-eight were females and 43 were males. In four cases, pregnancy was terminated after ultrasonography detected MMIHS, which was confirmed at autopsy in all cases. The duration of pregnancy was reported in 98 cases. Fifty-eight patients (59%) were born at term, 25 (25.5%) at 36 to 39 weeks of gestation, 12 (12%) at 32 to 35 weeks, and 3 (3%) at 31 weeks and less. Dystocia delivery caused by abdominal distention was reported in eight cases. In four cases Caesarean section was required, and in four cases the bladder was so distended that the baby could only be delivered vaginally after removal of 250, 500, 650, 500 mL of urine, respectively, from fetal bladder by paracentesis. The mean birth weight was normal (3 kg) for gestational age.
The clinical symptoms of MMIHS are similar to other neonatal intestinal obstructions. Characterized by abdominal distention, bile-stained vomiting, and absent or decreased bowel sounds, abdominal distention was a constant and early finding. A consequence of the distended, nonobstructed urinary bladder was relieved by catheterization. Of 182 cases 61 had bilious vomiting, and failure to pass meconium was clearly reported in only 23 cases. The majority of patients were not able to void spontaneously.
In the review by Puri and Shinkai, 19 sets of siblings affected with MMIHS were reported. Eighteen families had two affected siblings and one had three. Four sets of affected siblings occurred to consanguineous parents. In another case an affected child was born to a member of the family reported by Penman, and consanguinity was also present in these parents. In three further cases an elder sibling of the affected child died just after birth because of intestinal obstruction 30 or multiple abnormalities; in another case a sibling of the patient was affected by prune-belly syndrome.
The occurrence of MMIHS in 19 sets of affected siblings and consanguinity in four sets of parents suggest an autosomal recessive pattern of inheritance.
RADIOLOGIC FINDINGS
In the vast majorities of the 182 cases, radiologic evaluation usually suggested the diagnosis of MMIHS. Plain abdominal films showed either dilated small bowel loops or a gasless abdomen with evident gastric bubble. An enlarged urinary bladder was present in all patients who had cystography or ultrasonography (Fig. 102-5).
Intravenous urography or ultrasonography detected unilateral or bilateral hydronephrosis in 84 patients.
Forty-four patients had an upper gastrointestinal series both before and after laparotomy: hypoperistalsis or aperistalsis in stomach, duodenum, and small bowel was a constantly detected symptom.
In three cases reverse peristalsis from small bowel into the stomach was also observed.
In two cases hypoperistalsis was associated with gastroesophageal reflux, and in one case the esophagus was aperistaltic.
Barium enema showed microcolon in all 71 patients in whom this study was performed; in 39 cases malrotation was associated.
Coran
