Intraoperative measurement of esophagogastric junction cross-sectional area by impedance planimetry correlates with clinical outcomes of peroral endoscopic myotomy for achalasia: a multicenter study.

BACKGROUND: Peroral endoscopic myotomy (POEM) has been introduced as an endoscopic alternative to surgical myotomy. The endoluminal functional lumen imaging probe (endoFLIP) evaluates esophagogastric junction (EGJ) distensibility based on cross-sectional area and pressure in response to volume distension. The aim of this study was to evaluate whether there is a correlation between endoFLIP measurements during POEM and postoperative clinical outcomes in terms of symptom relief and development of post-procedure reflux.

METHODS: We conducted a retrospective review of achalasia patients who underwent POEM and intraoperative endoFLIP at three tertiary centers. Patients were divided into two groups based on clinical response measured by Eckardt score (ES): good response (ES < 3) or poor response (ES ≥ 3). Post-procedure reflux was defined as the presence of esophagitis and/or abnormal pH study. EGJ diameter, cross-sectional area, and distensibility measured by endoFLIP were compared.

RESULTS: Of the 63 treated patients, 50 had good and 13 had poor clinical response. The intraoperative final EGJ cross-sectional area was significantly higher in the good-response group versus poor-response group; median (interquartile range): 89.0 (78.5-106.7) versus 72.4 (48.8-80.0) mm(2) [p = 0.01]. The final EGJ cross-sectional area was also significantly higher in patients who had reflux esophagitis after POEM: 99.5 (91.2-103.7) versus 79.3 (57.1-94.2) mm(2) [p = 0.02].

CONCLUSION: Intraoperative EGJ cross-sectional area during POEM for achalasia correlated with clinical response and post-procedure reflux. Impedance planimetry is a potentially important tool to guide the extent and adequacy of myotomy during POEM.