Endoscopic implantation of polymethylmethacrylate augments the gastroesophageal antireflux barrier: a short-term study in a porcine model.

BACKGROUND AND AIMS: Endoscopic injection of filler agents into the esophagogastric junction has been developed to augment the antireflux barrier and decrease gastroesophageal reflux (GER). However, evidence of efficacy is lacking and serious complications have been reported in humans. The aim of this study was to assess whether endoscopic implantation of polymethylmethacrylate augments the antireflux barrier in a porcine model for GER.
METHODS: Large White pigs underwent esophageal manometry, gastric yield pressure (GYP), and gastric yield volume (GYV) measurements and implantation of PMMA in the distal esophagus under general anesthesia. After follow-up of 28 days, esophageal manometry and gastric yield measurements were repeated and animals sacrificed.
RESULTS: Implantation of PMMA was performed in 18 animals, and 14 animals survived 28 days. There was a significant increase in GYP (10.7 mmHg versus 8.1 mmHg; p = 0.017) and GYV (997 ml versus 393 ml; p < 0.001) after PMMA implantation, whereas resting LES pressure did not change significantly. Acute inflammatory changes and fibrous tissue deposits were found surrounding the PMMA implants during histology. One animal died after esophageal perforation and three others due to pneumonia (two) and colon perforation (one) in the postoperative period.
CONCLUSIONS: Endoscopic implantation of PMMA in the distal esophagus augments the antireflux barrier 28 days after the procedure. However, esophageal perforation points to the need for technical refinements to make the procedure safer.