Background and study aims: Pyloric stenosis is currently managed using open or laparoscopic pyloromyotomy. However,
with recent improvements in flexible endoscopic instrumentation and techniques, totally
peroral endoscopic approaches could reduce the invasiveness of myotomic procedures.
The aim of the study was to establish the feasibility and efficacy of endoscopic submucosal
pyloromyotomy in a porcine model.
Methods: Four pigs were included in a preliminary study and a 2-week survival study was performed
in another four pigs. An esophagogastroduodenoscope was inserted perorally into the
stomach. Saline solution was injected into the submucosal space proximal to the pylorus.
The gastric mucosa was incised and a 5-cm submucosal tunnel was created. After exposure
of the muscular layer in a submucosal tunnel, myotomy of the circular muscle layer
was performed until the longitudinal muscular layer was reached. Once myotomy was
completed, endoscopic clips were used to re-approximate the mucosal incision.
Results: Submucosal dissection, identification of the circular muscular layer, and pyloromyotomy
were achieved in all animals. Acute complications such as bleeding and perforation
were not observed in any cases. Median pyloric resting pressure was reduced from 16.5 mmHg
to 6.1 mmHg immediately after myotomy and 8.4 mmHg at 14 days after myotomy.
Conclusion: Peroral endoscopic submucosal pyloromyotomy appears to be technically feasible and
effective. Potential clinical applications, such as for infantile hypertrophic pyloric
stenosis or delayed gastric emptying after esophagectomy, could be considered after
confirmation of safety in additional survival studies.
