Identifying hiatal hernia with impedance planimetry during esophageal distension testing

Introduction Functional luminal imaging probe (FLIP) Panometry evaluates the esophageal response to distension involving biomechanics and motility. We have observed that hiatus hernia (HH) is evident during FLIP studies as a separation between the crural diaphragm (CD) and lower esophageal sphincter (LES) like what is seen with high-resolution manometry (HRM). The aim of this study was to compare FLIP findings to endoscopy and HRM in the detection of HH. Methods A total of 100 consecutive patients that completed FLIP during sedated endoscopy and HRM were included. LES-CD separation was assessed on FLIP and HRM with the presence of HH defined as LES-CD >= 1 cm. The agreement was evaluated using the kappa (kappa) statistic. Results Hiatal hernia was detected in 32% of patients on HRM and 44% of patients on FLIP with a substantial agreement between studies (84% agreement; kappa = 0.667). On FLIP, a 'new' HH (i.e. HH not observed on HRM) occurred in 14 patients and an enlarged HH (i.e., LES-CD >= 2 cm larger than on HRM) occurred in 11 patients. Among patients that also completed, timed barium esophagogram (TBE), delayed esophageal emptying on TBE was more common in patients with new or enlarged HH on FLIP than those without: 7/11 (64%) versus 2/12 (17%); p = 0.017. Conclusion FLIP can detect HH with a substantial agreement with HRM, though esophageal distension with FLIP testing appeared to elicit and/or enlarge a HH in an additional 25% of patients. Although this unique response to esophageal distension may represent a mechanism of dysphagia or susceptibility to reflux, additional study is needed to clarify its significance.

Automated summary

FLIP has a substantial agreement with HRM in detecting hiatal hernias, but distension with FLIP testing may lead to the occurrence or enlargement of hiatal hernia in some patients. Further study is needed to clarify the significance of this unique response to esophageal distension.