Fragmented and failed swallows on esophageal high-resolution manometry associate with abnormal reflux burden better than weak swallows.

Abstract

Association between proportions of hypomotile swallows on esophageal high-resolution manometry (HRM) and esophageal reflux burden remains incompletely understood. We investigated relationships between hypomotility, acid exposure time (AET), and mean nocturnal baseline impedance (MNBI) on ambulatory reflux monitoring. Clinical data, HRM, and ambulatory pH-impedance studies (performed off acid suppression) from patients with persisting reflux symptoms were reviewed from five international centers. AET (abnormal>6%) and MNBI (abnormal<2292ohms) were extracted from pH-impedance studies. Distal contractile integral (DCI) designated esophageal peristalsis into normal (DCI>450mmHg.cm.s), fragmented (DCI>450mmHg.cm.s with breaks>5cm), weak (DCI 100-450mmHg.cm.s), and failed (DCI<100mmmmHg.cm.s) sequences. Univariate and multivariate analyses were performed to identify motor associations of abnormal reflux burden. Of 351 patients (52.1±0.8years, 67%F), 29.3% had AET>6% and 61.8% had MNBI<2292ohms. On univariate analysis, both fragmented peristalsis and IEM associated with abnormal AET (P≤.01) and MNBI (P≤.03); reflux burden was more profound with >70% fragmented as well as ineffective sequences compared to ≤70% for each (P<.05 for each comparison). When weak and failed sequences within IEM were separately analyzed, ≥50% failed sequences predicted abnormal AET (P≤.009), and ≥50% weak sequences did not (P=.14). On multivariate regression, ≥50% failed sequences predicted abnormal AET (P=.02), and >70% ineffective sequences trended strongly (P=.069); >70% ineffective sequences predicted abnormal MNBI (P=.046), and >70% fragmented sequences trended strongly (P=.076). Breaks in esophageal peristaltic integrity seen with fragmented and failed sequences are more relevant to abnormal esophageal acid burden than weak sequences.