Endoscopic magnet placement into subadventitial tunnels for augmenting the lower esophageal sphincter using submucosal endoscopy: ex vivo and in vivo study in a porcine model (with video)

Abstract

Endolumenal therapies serve as a treatment option for GERD. This study aimed to determine if magnets could be placed endoscopically using the adventitial layer to create a subadventitial space near the esophagogastric junction to augment the lower esophageal sphincter using submucosal endoscopy. This study consisted of 2 phases, exvivo and invivo, with domestic pig esophagus. A long submucosal tunnel was made at the mid to lower esophagus. The muscularis propria was incised by a needle-knife within the submucosal tunnel. A subadventitial tunnel was made by biliary balloon catheter blunt dissection, and a magnet was deployed in the subadventitial space. The same maneuver was done within the opposing esophageal wall, with magnet placement in the opposing subadventitial space. Submucosal tunnels and subadventitial tunnels were successful without perforation exvivo in all attempts and in 9 of 10 cases, respectively. Magnets were deployed in the subadventitial space in 7 cases. Magnets connected and separated with atraumatic endoscope passage into the stomach and reconnected when the endoscope was withdrawn under fluoroscopy in 5 of 7 cases (71.4%). Invivo submucosal tunnels and subadventitial tunnels were successful in all 5 cases, and magnet augmentation was functionally active in 4 cases (80%). Subadventitial tunnels were feasible and could represent a new working space for endoscopic treatment. Endoscopic placement of magnets within the subadventitial space may be an attractive alternative endolumenal therapy for GERD.