Esophagogastric junction distensibility after fundoplication assessed with a novel functional luminal imaging probe

Abstract

Objective: The aim of the study was to compare the esophagogastric junction (EGJ) compliance in response to controlled distension in fundoplication (FP) patients and controls using the functional luminal imaging probe (FLIP).

Background: FP aims to replicate normal EGJ distensibility. FLIP is a new technology that uses impedance planimetry to measure intraluminal cross-sectional area (CSA) during controlled distension.

Methods: Ten controls and ten FP patients were studied with high-resolution esophageal pressure topography (HREPT) and then the FLIP placed across the EGJ. Deglutitive and interdeglutitive EGJ distensibility was assessed with volume-controlled distension. The FLIP measured eight CSAs spaced 4 mm apart within a cylindrical saline-filled bag along with the corresponding intrabag pressure.

Results: The EGJ formed an hourglass shape during distensions with the central constriction at the diaphragmatic hiatus. The distensibility of the hiatus was significantly greater during deglutitive relaxation in both subject groups, but FP patients exhibited reduced EGJ distensibility and compliance compared to controls. During the interglutitive period, the corresponding increase in intrabag pressures at larger volumes were also greater in FP patients implying a longer segment of EGJ constriction. The EGJ distensibility characteristics did not correlate with HREPT measures.

Conclusions: FLIP technology was used to compare EGJ distensibility in FP patients and control subjects. The least distensible locus within the EGJ was always at the hiatus. EGJ distensibility was significantly reduced, and the length of constriction increased in FP patients. Future FLIP studies will compare patients with and without post-FP dysphagia and gas bloat, symptoms suggestive of an overly restrictive FP.

Figures

Figure 1

Distal end of FLIP showing the electrode and pressure measurement loci within the bag (modified from McMahon et al.20).

Figure 2

A fluoroscopic image with a distended FLIP bag in situ straddling the EGJ following a 5-ml barium swallow.

Figure 3

Esophagogastric junction geometry as depicted by the FLIP. The hourglass shape of the EGJ narrowed at the hiatus (y-axis=0 cm) in both control subjects (black) and fundoplication patients (gray). The panels show the EGJ measurements with a 60-ml FLIP bag volume during the interdeglutitive period (a) and deglutitive relaxation (b).

Figure 4

Measured FLIP bag distensile pressure and estimated EGJ volume with the FLIP bag filled to 40 ml (lower dots), 50 ml (middle dots), and 60 ml (upper dots). Both control subjects (black) and fundoplication patients (gray) exhibited measureable EGJ distention during the interdeglutitive period (solid lines) and deglutitive relaxation (dashed lines) only with 50- and 60-ml FLIP bag volumes. Both groups exhibited increased EGJ volume during deglutitive relaxation. However, the distensile pressures associated with EGJ distention were consistently 8–10 mmHg greater in the FP patients compared to the control subjects (see also Table 3).

Figure 5

Esophagogastric junction compliance in controls and postfundoplication patients during the interdeglutitive period (a) and deglutitive relaxation (b). Median (5th–95th percentile); *p<0.05 vs. controls.