Mechanisms underlying the antireflux effect of Nissen fundoplication in children

Background/Purpose: 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. Copyright (C) 1998 by W.B. Saunders Company.