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 sphin cter (LES) relaxation in children. However, the effect of Nissen fundo plication on transient LES relaxation has not been investigated in chi ldren. This study examined the effect of Nissen fundoplication on moto r patterns of the LES in children with pathological GER. Methods: Esop hageal manometry and pH were recorded concurrently for 2 hours after a dministration 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 t o 3 months after surgery. Results: Nissen fundoplication virtually eli minated 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 numbe r of transient LES relaxation reduced significantly from 13 +/- 4 to 7 +/- 7, and the mean nadir LES pressures during swallow-induced LES re laxation 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 effect s of Nissen fundoplication may be based on changes of LES motor patter ns that result in incomplete LES relaxation and reduction of the numbe r of transient LES relaxation. Copyright (C) 1998 by W.B. Saunders Com pany.