title: A prospective study of botulinum toxin for internal anal sphincter hypertonicity in children with Hirschsprung's disease.
abstract: BACKGROUND
  Internal anal sphincter hypertonicity with nonrelaxation can cause persistent constipation and obstructive symptoms in children after surgery for Hirschsprung's disease. Intractable symptoms traditionally have been treated with anal myectomy, which may be ineffective or complicated by long-term incontinence. The authors evaluated prospectively the use of intrasphincteric botulinum toxin for these patients.
  
  
  METHODS
  Eighteen children were studied (age 1 to 13; median, 4 years). Botulinum toxin was injected (total dose 15 to 60 U) into 4 quadrants of the sphincter. Resting sphincter pressure was measured in 14 patients before and after injection. Ten have had 1 to 5 additional injections (total dose, 30 to 60 U per injection).
  
  
  RESULTS
  Four patients had no improvement in bowel function, 2 had improvement for less than 1 month, 7 had improvement for 1 to 6 months, and 5 had improvement more than 6 months. Nine of those with symptomatic improvement longer than 1 month had pressures measured, with a documented decrease in 8. Five with no significant clinical improvement had pressure measurements, with a decrease in 3. There were no adverse effects associated with botulinum toxin injection. Four children had new encopresis postinjection, which was mild and resolved in each case.
  
  
  CONCLUSIONS
  Intrasphincteric botulinum toxin is a safe and less-invasive alternative to myectomy for symptomatic internal sphincter hypertonicity. Persistent symptoms, despite a fall in sphincter pressure, suggest a nonsphincteric etiology. Repeat injections often are necessary for recurrent symptoms.
authors: Division of Pediatric Surgery, Department of Surgery, St Louis Children's Hospital and Washington University School of Medicine, St Louis, MO, USA.
authors: R K
authors: RK
authors: Minkes
authors: J C
authors: JC
authors: Langer
mesh_terms: D000293:Adolescent; D001003:Anal Canal / Q000187:drug effects*; D018726:Anti-Dyskinesia Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001905:Botulinum Toxins / Q000494:pharmacology / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006627:Hirschsprung Disease / Q000188:drug therapy*; D006801:Humans; D007223:Infant; D008297:Male; D011446:Prospective Studies
chemical_list: D018726:Anti-Dyskinesia Agents; D001905:Botulinum Toxins