title: Residual aganglionosis after pull-through operation for Hirschsprung's disease: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Most patients with Hirschsprung's disease (HD) have a satisfactory outcome after pull-through (PT) operation. However, some children continue to have persistent bowel symptoms after the initial operation and may require redo PT. Redo PT operation in HD is usually indicated for anastomotic strictures or residual aganglionosis (RA). We designed this meta-analysis to determine the incidence and outcome of RA among patients with HD following PT operation.
  
  
  METHODS
  A meta-analysis of redo PT operations for HD reported in the literature between 1985 and 2011 was performed. Detailed information was recorded in patients with RA and transition-zone bowel (TZB), including recurrent bowel problems, histological findings on repeat rectal biopsy, type of redo PT operation and outcome.
  
  
  RESULTS
  Twenty-nine articles reported 555 patients with redo PT operations. 193 (34.8%) patients demonstrated abnormal histological findings on rectal biopsy with 144 patients showing RA and 49 patients showing TZB. These 193 patients presented with persistent constipation (n = 135), recurrent enterocolitis (n = 45) and abnormal histology of the pulled-through bowel (n = 13). Mean age at redo PT was 4.4 years (range 4 months-17 years). Redo procedures were Duhamel (n = 57), transanal endorectal PT (n = 40), Soave (n = 35), Swenson (n = 10), posterior sagittal approach (n = 1) and not reported (n = 50). Follow-up information after redo PT was available in 134 (69.4%) patients and not available in 59 patients. Of the 134 patients, 99 (73.9%) patients had normal bowel habits, 19 patients had persistent constipation/soiling and 16 patients had recurrent enterocolitis.
  
  
  CONCLUSIONS
  This meta-analysis reveals that RA and TZB are the underlying causes of persistent bowel symptoms in one-third of all patients with HD requiring redo PT operation. Most patients have a satisfactory outcome after redo operation. Rectal biopsy should be performed in all patients with recurrent bowel problems after PT operation.
authors.affiliation: National Childrens's Research Centre, Our Lady's Children's Hospital, Crumlin, Dublin 12, Ireland.
authors.forename: Florian
authors.initials: F
authors.lastname: Friedmacher
authors.forename: Prem
authors.initials: P
authors.lastname: Puri
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003248:Constipation / Q000453:epidemiology / Q000601:surgery; D004760:Enterocolitis / Q000453:epidemiology / Q000601:surgery; D005242:Fecal Incontinence / Q000453:epidemiology / Q000601:surgery; D005260:Female; D006627:Hirschsprung Disease / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D011183:Postoperative Complications / Q000453:epidemiology / Q000601:surgery; D016737:Proctocolectomy, Restorative; D012008:Recurrence; D012086:Reoperation; D016896:Treatment Outcome