Identification of transient hiatal hernia on high-resolution manometry is associated with gastroesophageal reflux...

A swallow-induced transient hiatal hernia (tHH) is seen on high-resolution manometry (HRM) in some patients with type I esophagogastric junction (EGJ) morphology. As this finding is often overlooked, we evaluated the prevalence of tHH and its association with gastroesophageal reflux disease (GERD).

We conducted a retrospective, cross-sectional study on suspected GERD patients undergoing HRM and 24-hour pH monitoring (January 2018-October 2024). Patients with manometric HH at baseline, prior foregut surgery, esophageal disorders, end-stage respiratory disease, or on acid suppression as well as suboptimal studies were excluded. We compared GERD prevalence (DeMeester score [DMS] ≥14.72) between patients with tHH (swallow-induced LES-CD separation ≥1 cm in ≥10% of swallows) and those without tHH. The association strength was evaluated via multivariate logistic regression.

We included 207 patients with type I EGJ morphology (61.4% female; median age: 58 years): 31 with tHH and 176 without; the overall point prevalence of tHH was 15% (95%CI: 10.4-20.6). The tHH group showed a significantly higher prevalence of GERD (67.7% vs. 42%, P = 0.014) and a higher median DMS (24.1 [11.5-39] vs. 12.8 [4.9-26.8], P = 0.009) than the non-tHH group. The presence of tHH (any size or number of swallows) was an independent strong predictor of GERD (aOR: 3.50 [95%CI: 1.48-8.84], P = 0.006).

Around 15% of patients with normal EGJ morphology without manometric HH at baseline will exhibit tHH, which is predictive of abnormal distal esophageal acid exposure. This warrants further investigation and integration of tHH into multivariate diagnostic algorithms and future EGJ manometric classifications.