title: Risk factors associated with postnecrotizing enterocolitis strictures in infants.
abstract: BACKGROUND
  Survivors of necrotizing enterocolitis (NEC) often develop a post-NEC intestinal stricture, causing severe and prolonged morbidity.
  
  
  OBJECTIVE
  We first aimed to determine the incidence of post-NEC strictures. Second, we aimed to determine risk factors associated with intestinal post-NEC strictures.
  
  
  METHODS
  A total of 441 patients diagnosed with NEC Bell's stage ≥2 were retrospectively included in three academic pediatric surgical centers between January 2005 and January 2013. Clinical data were related to the occurrence of intestinal post-NEC strictures. Post-NEC strictures were defined as clinically relevant strictures with a radiological and/or surgical confirmation of this post-NEC stricture.
  
  
  RESULTS
  The median gestational age of the 337 survivors of the acute phase of NEC was 29weeks (range 24-41) and median birth weight was 1130g (range 410-4130). Of the survivors, 37 (17%) medically treated NEC patients developed a post-NEC strictures versus 27 surgically treated NEC patients (24%; p=0.001). Highest C-reactive protein (CRP) level measured during the NEC episode was associated with the development of post-NEC strictures (OR 1.20, 95% confidence interval 1.11-1.32; p=0.03). No post-NEC strictures were detected in patients with CRP levels <46mg/L.
  
  
  CONCLUSIONS
  This multicenter retrospective cohort study demonstrates an overall incidence of clinical relevant post-NEC strictures of 19%, with a higher rate (24%) in NEC cases treated surgically. Increased CRP levels during the NEC episode were associated with the development of post-NEC strictures.
authors.affiliation: Department of Pediatric Surgery, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands. Electronic address: f.h.heida@umcg.nl.
authors.forename: F H
authors.initials: FH
authors.lastname: Heida
authors.affiliation: Department of Pediatric Surgery, Pediatric Surgical Center Amsterdam, Amsterdam, the Netherlands.
authors.forename: M H J
authors.initials: MH
authors.lastname: Loos
authors.affiliation: Department of Pediatric Surgery, Pediatric Surgical Center Amsterdam, Amsterdam, the Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Stolwijk
authors.affiliation: Department of Pediatric Surgery, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: B J C
authors.initials: BJ
authors.lastname: Te Kiefte
authors.affiliation: Department of Pediatric Surgery, Pediatric Surgical Center Amsterdam, Amsterdam, the Netherlands.
authors.forename: S J
authors.initials: SJ
authors.lastname: van den Ende
authors.affiliation: Department of Neonatology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: Onland
authors.affiliation: Department of Pediatric Radiology, Academic Medical Center, Amsterdam, the Netherlands.
authors.forename: R R
authors.initials: RR
authors.lastname: van Rijn
authors.affiliation: Department of Pediatric Radiology, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Dikkers
authors.affiliation: Department of Neonatology, VU University Medical Center, Amsterdam, the Netherlands.
authors.forename: F A M
authors.initials: FA
authors.lastname: van den Dungen
authors.affiliation: Department of Neonatology, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: E M W
authors.initials: EM
authors.lastname: Kooi
authors.affiliation: Department of Neonatology, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: A F
authors.initials: AF
authors.lastname: Bos
authors.affiliation: Department of Pediatric Surgery, Beatrix Children's Hospital, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: J B F
authors.initials: JB
authors.lastname: Hulscher
authors.affiliation: Department of Pediatric Surgery, Pediatric Surgical Center Amsterdam, Amsterdam, the Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Bakx
mesh_terms: D020345:Enterocolitis, Necrotizing / Q000150:complications*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007415:Intestinal Obstruction / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Necrotizing enterocolitis; Post-NEC strictures; Risk factors