Esophageal impedance planimetry during per-oral endoscopic myotomy guides myotomy extent.

Abstract

Peroral endoscopic myotomy (POEM) is the standard treatment for achalasia. Functional luminal imaging probe (FLIP) technology enables objective measurement of lower esophageal sphincter (LES) geometry, with literature linking specific values to improved post-POEM outcomes. Our study assesses FLIP's intraoperative use in evaluating myotomy extent in real-time. Retrospective data from all patients undergoing POEM with intraoperative FLIP measurements were extracted from June 2020 to January 2023. The primary endpoint was intraoperative FLIP measurements, management changes, and symptom improvement (Eckardt score). Fourteen patients (age 56 ± 14years, BMI 28 ± 7kg/m2) were identified. Most patients were female (64%). Predominantly, patients presented with type II achalasia (50%). FLIP measurements were taken before and after myotomy, demonstrating increases in mean distensibility index (DI) 1.6 ± 1. 4 to 5.4 ± 2.1 mm2/mmHg (p < 0.05) and mean diameter (Dmin) 6 ± 1.8 to 10.9 ± 2.3mm (p < 0.05) at 50ml balloon fill. Additional myotomy was performed in one patient when an inadequate increase in FLIP values were noted. Mean operative time was 98 ± 28min, and there were no intraoperative complications. At the30-day follow-up, median Eckardt score decreased from mean apreoperative score of 7 ± 2 to apost-operative mean of 2 ± 3, with 10 patients (78%) having a score ≤ 2. In total, four patients experienced symptom recurrence, with repeat FLIP values revealing a significant decrease in DI from 7 ± 2.2 post-POEM to 2.5 ± 1.5 at recurrence. FLIP technology identified LES pathology in 3 out of 4 (75%) patients, facilitating referral to LES-directed therapy. Our study adds to the literature supporting the use of FLIP technology during thePOEM procedure, with most patients achieving ideal values after a standard-length myotomy. This suggests thepotential benefits of shorter myotomies guided by FLIP to achieve comparable outcomes and reduce postoperative GERD risk. Collaborative standardization of study designs and outcome measures is crucial for facilitating prospective trials and cross-setting outcome comparisons.