The Functional Lumen Imaging Probe Can Be Used to Assess Response to Peroral Endoscopic Myotomy

Clinical response after peroral endoscopic myotomy (POEM) is subjectively assessed using the Eckardt score (ES) or objectively tested using high-resolution manometry (HRM) or barium esophagram. The functional lumen imaging probe (FLIP) device can also be used endoscopically to objectively assess changes in function after achalasia treatment. What is not known is whether FLIP is comparable to HRM for objectively assessing clinical outcomes after POEM.

This single-center retrospective study evaluated a cohort of 87 patients (58% men; mean age, 51 ± 17 years) who had first-time treatment for achalasia (78% type II) and completed HRM, FLIP, and ES evaluation >6 months after treatment. Objective measures of achalasia improvement using HRM and FLIP were compared with ES scores for all patients. Clinical response was defined by ES ≤3, esophagogastric junction-distensibility index (EGJ-DI) >2.8 mm2/mm Hg at 40 to 50 mL balloon distension, integrated relaxation pressure (IRP) <15 mm Hg, and maximum EGJ diameter (MxEGJD) ≥14 mm at any diameter balloon distension. 

The overall clinical response as assessed by ES, IRP, MxEGJD, and EGJ-DI were 97.7%, 86.2%, 75.9%, and 92.0%, respectively. For predicting overall clinical response, the sensitivity of a normal IRP (87.1%; 95% confidence interval [CI], 78.0%-93.4%) was similar to that of a normal MxEGJD (75.3%; 95% CI, 64.7%-84.0%; P=.053) and normal EGJ-DI (91.8%; 95% CI, 83.8%-96.6%; P=.39). There was no difference in the area under the curve of a normal MxEGJD or EGJ-DI to predict a normal IRP (P=.956) after POEM.