An ambulant porcine model of acid reflux used to evaluate endoscopic gastroplasty.
BACKGROUND
There is a lack of suitable models for testing of therapeutic procedures for gastro-oesophageal reflux disease. Endoscopic sewing methods might allow the development of a new less invasive surgical approach to treatment of gastrointestinal disorders.


OBJECTIVE
To develop an animal model of gastro-oesophageal reflux for testing the efficacy of a new antireflux procedure, endoscopic gastroplasty, performed at flexible endoscopy without laparotomy or laparoscopy.


METHODS
At endoscopy a pH sensitive radiotelemetry capsule was sewn to the oesophageal wall, 5 cm above the lower oesophageal sphincter, in six large white pigs. Ambulant pH recordings (48-96 hours; total 447 hours) were obtained. The median distal oesophageal pH was 6.8 (range 6.4-7.3); pH was less than 4 for 9.3% of the time. After one week, endoscopic gastroplasty was performed by placing sutures below the gastro-oesophageal junction, forming a neo-oesophagus of 1-2 cm in length. Postoperative manometry and pH recordings (24-96 hours; total 344 hours) were carried out.


RESULTS
Following gastroplasty, the median sphincter pressure increased significantly from 3 to 6 mm Hg and in length from 3 to 3.75 cm. The median time pH was less than 4 decreased significantly from 9.3% to 0.2%.


CONCLUSIONS
These are the first long term measurements of oesophageal pH in ambulant pigs. The finding of spontaneous reflux suggested a model for studying treatments of reflux. Endoscopic gastroplasty increased sphincter pressure and length and decreased acid reflux.
D000818:Animals; D019723:Endoscopes; D004724:Endoscopy / Q000379:methods*; D004947:Esophagus / Q000503:physiopathology; D005069:Evaluation Studies as Topic; D005260:Female; D005764:Gastroesophageal Reflux / Q000503:physiopathology / Q000601:surgery*; D015391:Gastroplasty / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008365:Manometry / Q000295:instrumentation / Q000379:methods; D008954:Models, Biological; D013552:Swine; D013686:Telemetry / Q000295:instrumentation / Q000379:methods