EndoFLIP system for the intraoperative evaluation of peroral endoscopic myotomy.

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 postoperative 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.