title: EndoFLIP system for the intraoperative evaluation of peroral endoscopic myotomy.
abstract: BACKGROUND
  Peroral endoscopic myotomy (POEM) has been recently introduced in clinical practice for the treatment of achalasia. The endoluminal functional lumen imaging probe (EndoFLIP) system) uses impedance planimetry for the real-time measurement of the diameter of the oesophago-gastric junction.
  
  
  OBJECTIVE
  The aim of this study is to prospectively evaluate the effect of POEM on the oesophago-gastric junction using EndoFLIP.
  
  
  METHODS
  All the patients who underwent POEM in a single centre between April and July 2013 were enrolled in the study. EndoFLIP was used intraoperatively, immediately before and after POEM. During follow-up patients underwent oesophagogastroduodenoscopy, oesophageal pH monitoring and manometry. Clinical outcomes were compared with the diameter of the oesophago-gastric junction after POEM.
  
  
  RESULTS
  In total, 23 patients (12 males, mean age 51.7 years) were enrolled, and 21 underwent POEM successfully. Preoperative mean basal lower oesophageal sphincter pressure was 42.1 mmHg (±17.6). Before POEM, the mean oesophago-gastric junction diameter and cross-sectional area were 6.3 mm (±1.8) and 32.9 mm(2) (±23.1), respectively. After treatment, the mean diameter and cross-sectional area of the oesophago-gastric junction were 11.3 mm (±1.7 SD) and 102.38 mm(2) (±28.2 SD), respectively. No complications occurred during a mean follow-up of 5 months. Median post-operative Eckardt score was 1. Three patients (14.3%) referred heartburn. Follow-up studies revealed gastro-oesophageal reflux disease (GORD) in 57.1% of patients and oesophagitis in 33.3%. No correlations were observed between the diameter of oesophago-gastric junction after POEM and symptoms relief, GORD incidence and lower oesophageal sphincter pressure.
  
  
  CONCLUSIONS
  The diameter of oesophago-gastric junction substantially increases after POEM. EndoFLIP is a reliable method for the intraoperative evaluation of oesophago-gastric junction diameter. However, the real usefulness of this technology after POEM remains controversial.
authors.affiliation: Digestive Endoscopy Unit, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Familiari
authors.affiliation: Digestive Endoscopy Unit, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gigante
authors.affiliation: Digestive Endoscopy Unit, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Marchese
authors.affiliation: Digestive Endoscopy Unit, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Ivo
authors.initials: I
authors.lastname: Boskoski
authors.affiliation: Digestive Endoscopy Unit, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Bove
authors.affiliation: Digestive Endoscopy Unit, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Tringali
authors.affiliation: Digestive Endoscopy Unit, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Perri
authors.affiliation: Department of Geriatrics, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Graziano
authors.initials: G
authors.lastname: Onder
authors.affiliation: Digestive Endoscopy Unit, Gemelli University Hospital, Università Cattolica del Sacro Cuore, Rome, Italy.
authors.forename: Guido
authors.initials: G
authors.lastname: Costamagna
keywords: Achalasia; EndoFLIP; endoscopy; oesophageal manometry; oesophago-gastric junction; oesophagus; peroral endoscopic myotomy