Regional variation in distal esophagus distensibility assessed using the functional luminal imaging probe (FLIP)

Background This study aimed to evaluate the spatial variation in esophageal distensibility in normal subjects using a novel multichannel functional luminal imaging probe (FLIP). Methods Ten healthy subjects (four men, age 21–49 years) were evaluated during endoscopy with a high-resolution impedance planimetry probe (FLIP) positioned through the esophagogastric junction (EGJ) and distal 10 cm of the esophageal body. Stepwise bag distensions using 5-mL increments from 0 to 60 mL were conducted, and simultaneous measurements of cross-sectional area (CSA) and the associated intrabag pressure from each subject were analyzed using a customized MATLAB™ program. The distensibility along the esophagus was determined and compared between the EGJ and interval locations at 2–5 cm and 6–10 cm above the EGJ. Key Results The pressure–CSA relationship was nearly linear among sites at lower pressures (0 to 7.5 mmHg) and reached a distension plateau at pressures ranging from 8 to 24 mmHg. The location of greatest distensibility was 4 cm above the EGJ. Although the CSAs of individual recording loci were not significantly different, there was a significant difference between the mean CSAs when comparing the region 2 to 5 cm proximal to EGJ with that 6 to 10 cm proximal to the EGJ. Conclusions & Inferences There were significant regional differences in distensibility along the distal esophagus with lower values in the proximal part compared with more distal part. The greatest distensibility was noted to occur at about 4 cm above the EGJ in close proximity to the location of the contractile deceleration point and phrenic ampulla.