Related Experiment Video
Updated: Oct 9, 2026
Robotic Myotomy and Partial Fundoplication for Achalasia
Published on: August 11, 2023
Biomechanical Assessment During High-Resolution Impedance Manometry Enhances Characterization of Inconclusive
Aidan D Smires1, Wenjun Kou1, John E Pandolfino1
1Kenneth C. Griffin Esophageal Center of Northwestern Medicine, Department of Medicine, Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Background:
Esophagogastric junction outflow obstruction (EGJOO) identified on high-resolution manometry (HRM) remains a clinically heterogeneous and inconclusive finding. Additional complementary testing with functional lumen imaging probe (FLIP) or timed barium esophagram (TBE) is recommended to confirm clinically relevant obstruction. We aimed to assess the association of novel Four-Dimensional (4D) HRM metrics against FLIP and TBE outcomes among symptomatic patients with inconclusive EGJOO on HRM.
Methods:
Adult patients with inconclusive HRM-EGJOO who completed corresponding FLIP and TBE studies were identified for inclusion in a cross-sectional, retrospective study. Primary 4D HRM metrics of EGJ opening, EGJ distensibility index (4D EGJ-DI), and 4D maximum EGJ diameter were analyzed relative to reference outcomes defined by FLIP and esophagram.
Results:
Among 123 patients (mean age 59 years; 60% female), 4D EGJ-DI and 4D maximum EGJ diameter differed significantly across FLIP and TBE outcome categories (all p < 0.01). Lower 4D EGJ-DI and lower 4D maximum EGJ diameter were associated with reduced EGJ opening on FLIP and abnormal retention on esophagram. There were 0 patients with normal EGJ opening on FLIP that had 4D maximum EGJ diameter < 8.0 mm and 0 patients with reduced EGJ opening on FLIP that had a 4D EGJ-DI > 2.2 mm2/mmHg and 4D maximum EGJ diameter > 10.2 mm.
Conclusions:
By integrating biomechanical assessment of EGJ opening with conventional pressure metrics, 4D HRM provides complementary physiologic information for evaluating esophageal motor function. This additional information may improve characterization of patients with inconclusive EGJOO.
