Elevated average maximum intrabolus pressure on high-resolution manometry is associated with esophageal dysmotility and delayed esophageal emptying on timed barium esophagram

BACKGROUND: Intrabolus pressure (IBP) recorded by high-resolution manometry (HRM) portrays the compartmentalized force on a bolus during esophageal peristalsis. HRM may be a reliable screening tool for esophageal dysmotility in patients with elevated average maximum IBP (AM-IBP). Timed barium esophagram (TBE) is a validated measure of esophageal emptying disorders, such as esophagogastric junction outflow obstruction and achalasia. This study aimed to determine if an elevated AM-IBP correlates with esophageal dysmotility on HRM and/or delayed esophageal emptying on TBE. METHODS: A retrospective analysis of all HRM (unweighted sample n = 155) performed at a tertiary referral center from 09/2015–03/2017 yielded a case group (n = 114) with abnormal AM-IBP and a control group (n = 41) with a normal AM-IBP (pressure < 17 mmHg) as consistent with Chicago Classification 3. All patients received a standardized TBE, with abnormalities classified as greater than 1 cm of retained residual liquid barium in the esophagus at 1 and 5 min or as tablet retention after 5 min. RESULTS: AM-IBP was significantly related to liquid barium retention (p = 0.003) and tablet arrest on timed barium esophagram (p = 0.011). A logistic regression model correctly predicted tablet arrest in 63% of cases. Tablet arrest on AM-IBP correlated with an optimal prediction point at 20.1 mmHg on HRM. Patients with elevated AM-IBP were more likely to have underlying esophageal dysmotility (95.6% vs. 70.7% respectively; p < 0.001), particularly esophagogastric junction outflow obstruction disorders. Elevated AM-IBP was associated with incomplete liquid bolus transit on impedance analysis (p = 0.002). CONCLUSIONS: Our findings demonstrate that an elevated AM-IBP is associated with abnormal TBE findings of esophageal tablet retention and/or bolus stasis. An abnormal AM-IBP (greater than 20.1 mm Hg) was associated with a higher probability of retaining liquid bolus or barium tablet arrest on TBE and esophageal dysmotility on HRM. This finding supports the recent incorporation of IBP in Chicago Classification v4.0.