Esophagogastric junction compliance on impedance planimetry (EndoFLIP™) following peroral endoscopic myotomy (POEM) predicts improvement in postoperative eckardt score.

Background: Peroral endoscopic myotomy (POEM) is a mainstay of treatment for achalasia. Tailored myotomy based on compliance, as measured with impedance planimetry (FLIP), has yet to be described. In this study we describe the associations between Eckardt score, postoperative GERD, and compliance.

Methods: A retrospective review of a prospectively maintained database was performed, evaluating patients who underwent POEM and intraoperative FLIP between January 2019 and November 2021. Group comparisons were made using two-tailed Wilcoxon rank-sum and Fisher's exact tests. Spearman's correlation coefficients (r) were used to assess the relationship between compliance and outcomes, all with two-tailed statistical significance of p < 0.05.

Results: Thirty five patients underwent POEM with intraoperative FLIP. At a 30 mL and 40 mL fill, respectively, compliance increased by 80% (180 ± 152%) and 77% (177 ± 131%) from pre to post myotomy. Mean Eckardt score improved from 5.5 ± 2.6 preoperatively to 1.3 ± 1.6 and 1.8 ± 1.9 at first and second follow up, respectively. Median times to first and second follow up were 22 days (IQR 16-23) and 65 days (IQR 58-142). A higher compliance at 40 mL fill was moderately associated with lower Eckardt score at first (r = -0.49, p = 0.012) and second (r = -0.64, p = 0.014) follow up. Post myotomy compliance ≥ 125 mm/mmHg at 40 mL fill was associated with lower Eckardt scores, < 3, at first (0.4 ± 0.5 vs 1.8 ± 1.3, p = 0.008) and second (0.4 ± 0.5, vs 2.0 ± 1.4, p = 0.027) follow up. Compliance ≥ 125 mm/mmHg performed better than previously defined ideal ranges of DI and CSA in predicting postoperative Eckardt scores. Compliance was not significantly associated with development of postoperative GERD.

Conclusions: A target post myotomy compliance of ≥ 125 mm/mmHg at a 40 mL fill is associated with normal Eckardt scores at first and second postoperative visits, and performs better than previously defined ideal ranges of DI and CSA in predicting post-operative Eckardt scores. Compliance is a poor predictor of developing GERD after POEM.