title: Gastric emptying after fundoplication is dependent on changes in gastric volume and compliance.
abstract: OBJECTIVE
  Nissen gastroesophageal fundoplication (GEF) increases gastric emptying (GE); however, the duration and the mechanisms for this improvement in GE remain unclear. The aim of this study was to evaluate the effects of a GEF on GE of a mixed meal, and to determine the correlation between GE and changes in intragastric pressure (IGP) and compliance.
  
  
  METHODS
  Using a radiolabeled mixed meal, GE was measured preoperatively 15 and 30 days after operation in 24 Sprague-Dawley rats divided into SHAM and GEF groups. Results were expressed as percent gastric retention at 90 minutes (GRg90), and time to evacuate 50% of the isotope meal (T1/2). Changes in IGP and compliance were determined at the same time-points using a different set of 20 rats.
  
  
  RESULTS
  Fifteen days after surgery, GR90 and T1/2 in the GEF group were reduced significantly when compared with preoperative values but returned to near preoperative values 30 days postoperation. In contrast, rats from the SHAM group showed no change in GR90 and T1/2 at 15 days and 30 days postoperation. Immediately after GEF, maximal distension of the stomach resulted in pressures 65% higher than those recorded before operation (20.2 v 11.7 mm Hg; P< .05), which persisted on the 15th postoperative day (17.7 v 10.7 mm Hg; P<.05). On the 30th postoperative day, however, there was no difference in the IGP between rats undergoing GEF compared with those undergoing a SHAM operation (11.7 v 12.0 mm Hg; P < .05). Similarly, mean gastric compliance decreased significantly immediately after and 15 days after GEF, but returned to preoperative levels 30 days after the operation.
  
  
  CONCLUSIONS
  In a rat model, GEF produces a transitory increase in GE, which is related to a simultaneous decrease in gastric volume and compliance. However, 30 days after GEF, associated with an elevated IGP, gastric volume increases and GE returns to preoperative levels.
authors.affiliation: Department of Surgery, UCLA School of Medicine, Los Angeles, CA 90095, USA.
authors.forename: J
authors.initials: J
authors.lastname: Bustorff-Silva
authors.forename: C A
authors.initials: CA
authors.lastname: Perez
authors.forename: E W
authors.initials: EW
authors.lastname: Fonkalsrud
authors.forename: C
authors.initials: C
authors.lastname: Hoh
authors.forename: H E
authors.initials: HE
authors.lastname: Raybould
mesh_terms: D000818:Animals; D018662:Fundoplication; D005746:Gastric Emptying; D005764:Gastroesophageal Reflux / Q000503:physiopathology / Q000601:surgery; D008297:Male; D011184:Postoperative Period; D011312:Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000502:physiology; D013997:Time Factors