Interactive Panometry: Using Proximal Balloon Distension During Functional Lumen Imaging Probe Panometry to Enhance Motility Evaluation of Inhibitory Function.

BACKGROUND/AIMS: : Descending inhibition facilitates esophageal peristalsis and lower esophageal sphincter relaxation, processes impaired in achalasia. The functional lumen imaging probe (FLIP) assesses esophageal motility and esophagogastric junction (EGJ) opening but does not directly evaluate neuromyogenic function. We developed "Interactive Panometry," a novel FLIP maneuver utilizing proximal balloon distension to physiologically provoke descending inhibition.

METHODS

: Four healthy volunteers and 5 patients with untreated type II achalasia underwent FLIP Panometry with proximal esophageal balloon distension (20-mm in controls, 20-30 mm in achalasia) at 50-mL and 60-mL fill volumes. EGJ distensibility index (EGJ-DI), intra-bag pressure, and contractile response were measured before, during, and after distension. In 3 controls, simultaneous high-resolution manometry was performed to verify physiologic responses.

RESULTS

: Feasibility was first demonstrated in control subjects using simultaneous FLIP and high-resolution manometry. Proximal balloon distension induced cessation of repetitive antegrade contractions with concurrent increases in EGJ-DI and reductions in FLIP pressure. At a 50-mL FLIP fill volume and 20-mm proximal balloon distension, controls demonstrated a mean EGJ-DI increase of 3.5 mm²/mmHg and a 16.5-mmHg pressure reduction, whereas achalasia cases exhibited an EGJ-DI increase of 0.1 mm²/mmHg and a 0.2 mmHg pressure reduction. With 30-mm proximal distension, achalasia cases showed an EGJ-DI increase of 0.2 mm²/mmHg and a 5.3-mmHg pressure reduction. Trends were similar at 60-mL fill volumes.

CONCLUSIONS

: Interactive Panometry is a feasible FLIP maneuver physiologically consistent with descending inhibition. This proof-of-concept study supports further investigation in larger cohorts of symptomatic patients with suspected esophageal dysmotility to validate its role in assessing descending inhibition.