0 It is functional obstruction of the large intestine due to the lack of intramural ganglion cells distal to the gastrointestinal tract. Craniocaudal migration of ganglia in the intestine is impaired.
0 Hirschsprung's disease is an anomaly of neural crest development. The ganglia of the involved segment are not developed.
0 There are abnormal peristaltic movements and the basic pathophysiology is the absence of intestinal nerve plexuses.
0 As a result, there is always an aganglionic segment in the distal (anal region).
0 70% of Hirschsprung patients have total colonic aganglionosis.
0 occurs in 60-70% of the rectosigmoid region, 20% in the extraperitoneal rectum, 5% in the entire colon, and 1% in the entire GIS.
It is seen with a frequency of 0 1/4500-5000 and 70-80% in males.
0 It is common in term and normal birth weight babies.
0 It is multifactorial genetically transmitted. Chagas disease and surgery can also cause aganglionosis.
0 Due to the common neuroectodermal source, it can be seen together with diseases of the same origin such as neuroblastoma and neurofibromatosis.
Its association with Down syndrome is common.
0 GIS, CNS, CVS and eye anomalies may accompany.
0 Shah Waardenburg syndrome: Megacolon + facial deformity + congenital deafness + white hair
0 Ondine syndrome: Hirschsprung's disease + congenital central hypoventilation
Clinic and Diagnosis
In 70-80% of cases, there is inability to remove meconium, abdominal distension and biliary vomiting.
The most typical and earliest symptom is removal of meconium more than 24-48 hours later.
There may be signs of dehydration and sepsis.
> 1 year old children have complaints of constipation, attacks of enterocolitis or meteorism.
There is developmental delay, a swollen abdomen, and peripheral edema due to hypoproteinemia and weak extremities.
Peristaltic waves may be seen in the abdomen and fecalomas may be palpated. Their abdomens are swollen and tense.
It is typical that the rectum envelops the little finger and gas and meconium gush from the anus when the finger is removed.
On rectal examination, 55% of the rectum is empty, 40% of small stools and 15% of the cases are hard stools.
There are signs of distal intestinal obstruction in ADBG. The absence of gas shadow in the rectum despite the presence of enlarged intestinal loops favors Hirschsprung's disease. If there is a perforation, there may be free air.
It is typical to see a narrow and overlying enlarged colon on the colon graphy. Failure to discharge the barium after 24 hours also strengthens the diagnosis.
It is pathognomonic to see the transition zone from the ganglionic segment to the aganglionic segment on contrast-enhanced radiographs performed with the Neuhauser technique.
In anorectal manometry, there is no relaxation in the internal sphincter.
Definitive diagnosis is made by full thickness rectal biopsy.
Attention should be paid to psychogenic or habitual constipation.
Meconium plug syndrome, small left colon syndrome, meconium ileus, anal fissure or stenosis
Complications
• Its most serious complication is enterocolitis and its most important indicator is diarrhea.
• The risk of enterocolitis is higher in people with Down syndrome.
• If left untreated, perforation occurs and is often perforated from the appendix and cecum.
• The most serious form of enterocolitis is toxic megacolon. Fever, bilious vomiting, explosive diarrhea, distention, dehydration, and shock ensue. It is 80% mortal.
• Other complications are inflammatory enterocolitis, appendicitis, mucosal ulcers, growth retardation.
Treatment
• The proximal ganglionic segment is anastomosed to the anus, with the internal sphincter partially preserved and the external sphincter completely preserved, and the aganglionic segment in between is removed.
• Duhamel surgery and its various variants are most commonly used.
• Pullthrough surgery can be performed.
• Enterostomy can be performed before definitive surgery in newborns.