Endoscopic SIS injection into the lower oesophageal sphincter in dogs

Aim To determine the usefulness of endoscopically-delivered small intestinal submucosa (SIS) as a scaffold in enhancing the lower oesophageal sphincter (LOS) pressures. Methods Six dogs were endoscopically injected - four with the SIS and two with its glycerin carrier. Manometry was performed prior to injection and every four weeks post-op. Results Adequate and site correct injections were made in four dogs. In one dog, significant augmentation of pressures were obtained at four weeks. None had significant changes in pressure at eight weeks, differences in length at either four or eight weeks or significant differences in the thickness of the examined layers. Four of the six had capillary cushions on pathological examination. The dog injected with the carrier had a loose and disorganised collection, while the others were well organised. Conclusion SIS is a biologically compatible material. Lack of an animal model for gastro-oesophageal reflux disease (GORD) makes determining the ability of injections of SIS to combat reflux problematic.