title: Mechanisms underlying the antireflux effect of Nissen fundoplication in children.
abstract: OBJECTIVE
  It is reported that the main mechanism responsible for gastroesophageal reflux (GER) is transient lower esophageal sphincter (LES) relaxation in children. However, the effect of Nissen fundoplication on transient LES relaxation has not been investigated in children. This study examined the effect of Nissen fundoplication on motor patterns of the LES in children with pathological GER.
  
  
  METHODS
  Esophageal manometry and pH were recorded concurrently for 2 hours after administration of apple juice (10 mL/kg). In seven children documented to have pathological GER by prolonged esophageal pH monitoring (%time pH less than 4.0>5.0), studies were performed preoperatively and 1 to 3 months after surgery.
  
  
  RESULTS
  Nissen fundoplication virtually eliminated reflux in all patients. Percentage of time pH was less than 4.0 reduced from 15+/-9 to 0+/-0. Basal LES pressure did not change significantly (pre, 21+/-10 mm Hg v post, 27+/-9 mm Hg). The number of transient LES relaxation reduced significantly from 13+/-4 to 7+/-7, and the mean nadir LES pressures during swallow-induced LES relaxation and transient LES relaxation increased significantly from 1+/-1 mm Hg to 13+/-5 mm Hg and from 0+/-0 mm Hg to 11+/-7 mm Hg, respectively.
  
  
  CONCLUSIONS
  Our findings suggest the antireflux effects of Nissen fundoplication may be based on changes of LES motor patterns that result in incomplete LES relaxation and reduction of the number of transient LES relaxation.
authors.affiliation: Department of Pediatric Surgery, Osaka University Medical School, Yamadaoka, Suita, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kawahara
authors.forename: K
authors.initials: K
authors.lastname: Imura
authors.forename: M
authors.initials: M
authors.lastname: Yagi
authors.forename: A
authors.initials: A
authors.lastname: Yoneda
authors.forename: H
authors.initials: H
authors.lastname: Soh
authors.forename: Y
authors.initials: Y
authors.lastname: Tazuke
authors.forename: A
authors.initials: A
authors.lastname: Okada
mesh_terms: D002648:Child; D002675:Child, Preschool; D015154:Esophageal Motility Disorders / Q000150:complications* / Q000175:diagnosis; D005260:Female; D018662:Fundoplication; D005764:Gastroesophageal Reflux / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008365:Manometry; D008991:Monitoring, Physiologic; D011184:Postoperative Period; D011300:Preoperative Care; D011312:Pressure; D011446:Prospective Studies; D018709:Statistics, Nonparametric