Wednesday, January 19, 2011

Hirschsprung disease (intestinal Aganglioza, congenital megacolon)

Hirschsprung disease (intestinal Aganglioza, congenital megacolon) Hirschsprung disease is a congenital disorder of the enteric nervous system and is characterized by the absence of ganglion cells in the distal colon forcing its functional obstruction. Maforitatea cases are diagnosed in the newborn period nascut.Boala Hirschsprung should be considered in any newborn not remove the meconium in the first 24-48 hours after birth. Although double-contrast radiology is useful in diagnosis, rectal biopsy remains the criterion standard.O Once the diagnosis is made, treatment is excision of the portion of intestine is broken, aganglionic, and colono-rectal anastomosis. Approximately 20% of affected children associated cardiovascular abnormalities in the nervous system, urological or gastrointestinal. Hirschsprung disease is associated with the following conditions: Down-syndrome syndrome, Yemen, piebaldismul Neurocristopatie-syndrome, Goldberg-Shprintzen syndrome Waardenburg-Shah-syndrome, multiple endocrine neoplasia type II -Congenital hypoventilation syndrome. Untreated, congenital megacolon has a mortality rate of 80%.
Pathogenesis and causes Aganglioza congenital disease of the colon defines Hirschsprung.Aganglioza begins with anus, which is always involved, and continues a distance variabila.Ambele nerve plexus: mienteric-Auerbach, and the submucous-Meissner, missing colon causes loss of function and lack of precise peristalticii.Mecanismul underlying disease is unknown. Crest derived enteric ganglion cells during fetal development neurala.In normal neuroblastii small intestine may be seen beginning with the seventh week of gestation and will arrive in the colon Twelve week. A possible etiology of Hirschsprung disease is abnormal migration neuroblastilor to intestin.Alternativ, defects can occur in the survival, proliferation and their differentiation. Additionally it was noted that lymph node cells that have migrated are electrically inactive, another important factor is Cajal cells, which connects the pacemaker role of enteric nerves and intestinal myocytes. In patients with Hirschsprung disease, is increased innervate extrinsic and both cholinergic and adrenergic inervatii also predominate.
Signs and symptoms Symptoms usually begins in young children and include: Absence of meconium-elimination -Lack seat after the first 24-48 hours after birth -Constipation, bloating -Vomiting, watery diarrhea Reduced weight-gain Slow-growth in children under 5 years -Malabsorption, anemia Food-refusal, bilious vomiting. Approximately 10% of the children will present with diarrhea due to bacterial enterocolitis intestinale.Debutul stasis disease occurs in adolescents with chronic constipation and weight gain sarac.10% of patients had a positive family medical history. Most severe complication is the development of enterocolitis due to pathogenic bacterial colonization toxic by prolonged stasis.
Diagnosis The laboratory tests include: -CBC: hematocrit, leukocyte and erythrocyte count, -Coagulation tests and platelet count in case of surgical inerventie Abdominal X-ray-and double-contrast colon distensionat highlights Anorectal manometry reflezul-detect-relaxation of internal anal sphincter after rectal distension of the lumen, this reflex is usually absent in patients Rectal-exam-biopsy diagnosis.
Treatment Treatment of invasive or noninvasive techniques include different intestinal excision: -For patients with a short segment of intestine affected rectal myomectomy is performed -For a longer segment of bowel to be resected classic or laparoscopic surgery is performed with rectal anastomosis. A new therapy is tried stem cell transplantation. For enterocolitis toxic drugs used are broad spectrum antibiotics: ampicillin, metronidazole, gentamicin. Surgery patients receive injections of botulinum toxin type A to regulate bowel movements. After bowel resection surgery 90% of patients had a normal chair.

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