Assessment of the Neuro-glio-epithelial Unit (NGEU) in Biopsies Taken During Peroral Endoscopic Myotomy (POEM) for Achalasia: a Feasibility and Safety Study.

"In total, 14 biopsies are performed with a pediatric biopsy forceps belonging to the study center: 3 biopsies at 3-6 cm above cardia, contralaterally from POEM, of which 2 are placed in nitrogen and 1 in formol for histopathological analysis; 3 biopsies at the cardia, contralaterally from POEM, of which 2 are placed in nitrogen and 1 in formol for histopathological analysis; 4 biopsies of the muscularis propria (exposed during POEM) at 3-6 cm above cardia, of which 3 are placed in nitrogen and 1 in formol for histopathological analysis; 4 biopsies of the muscularis propria at the cardia, of which 3 are placed in nitrogen and 1 in formol for histopathological analysis; The biopsies intended for histopathological analysis will be analyzed in FFOCT before histopathological analysis. The FFOCT analysis take place for the patient inclued after than 10 november 2020.~The biopsies are taken by the gastroenterologist who performs the POEM and is assisted by an endoscopy-specialized nurse."