Esophagogastric Junction Distensibility on Functional Lumen Imaging Probe Topography Predicts Treatment Response in Achalasia-Anatomy Matters!

Abstract

Introduction: To compare the utility of the distensibility index (DI) on functional lumen imaging probe (FLIP) topography to other esophagogastric junction (EGJ) metrics in assessing treatment response in achalasia in the context of esophageal anatomy.

Methods: We prospectively evaluated 79 patients (at ages 17-81 years; 47% female patients) with achalasia during follow-up after pneumatic dilation, Heller myotomy, or per-oral endoscopic myotomy with timed barium esophagram, high-resolution impedance manometry, and FLIP. Anatomic deformities were identified based on consensus expert opinion. Patients were classified based on anatomy and EGJ opening to determine the association with radiographic outcome and Eckardt score (ES).

Results: Twenty-seven patients (34.1%) had an anatomic deformity-10 pseudodiverticula at myotomy, 7 epiphrenic diverticula, 5 sigmoid, and 5 sinktrap. A 5-minute column area of >5 cm was best associated with an ES of >3, with a sensitivity of 84% (P = 0.0013). Area under the curve for EGJ metrics in association with retention was as follows: DI, 0.90; maximal EGJ diameter, 0.76; integrated relaxation pressure, 0.64; and basal esophagogastric junction pressure, 0.53. Only FLIP metrics were associated with retention given normal anatomy (DI 2.4 vs 5.2 mm/mm Hg and maximal EGJ diameter 13.1 vs 16.6 mm in patients with and without retention, respectively; P values < 0.0001 and 0.002). Using a DI cutoff of <2.8 as abnormal, 40 of 45 patients with retention (P = 0.0001) and 23 of 25 patients with an ES of >3 (P = 0.02) had a low DI and/or anatomic deformity. With normal anatomy, 21 of 22 patients with retention had a low or borderline low DI.

Discussion: The FLIP DI is most useful metric for assessing the effect of achalasia treatment on EGJ opening. However, abnormal anatomy is an important mediator of outcome and treatment success will be modulated by anatomic defects that impede bolus emptying.

Figure 1.

Anatomical deformities noted in treated achalasia. A) pseudodiverticulum at the myotomy site, B) epiphrenic diverticulum, C) sigmoid deformity D) sinktrap deformity. Measurement of column height and area is shown for each figure.

Figure 2.

Esophagogastric junction metrics based on retention outcome in 52 patients with normal anatomy. Statistically significant differences are shown. Abbreviations: DI: distensibility index, EGJP: basal esophagogastric junction pressure, IRP: integrated relaxation pressure, MxEGJD: maximal EGJ diameter

Figure 3.

Degree of retention based on distensibility index (DI) is shown. P value for Spearman’s rho is <.0001.

Figure 4.

Outcomes in groups based on distensibility index (DI) and anatomy. Statistically significant differences are shown. Outliers are marked with ◆.

Figure 5.

Outcomes in groups based on maximal EGJ diameter (MxEGJD) and anatomy. Statistically significant differences are shown. Outliers are marked with ◆.

Figure 6.

Case examples of retention driven by A) closed EGJ, and B) anatomic deformity in the presence of an open EGJ. Five-minute timed barium esophagram images are shown on the left. Composite figures with FLIP topography (top) and pressure and volume curves focused on the 60 ml distension volume (bottom) are shown on the right. The EGJ location is marked, and the distensibility index (EGJ-DI^60ml) is shown. Abbreviations: DI: distensibility index, EGJ: esophagogastric junction, FLIP: functional lumen imaging probe

Figure 7.

Outcome analysis tree for retention (A) and Eckardt score (B). A breakdown of patients and % based on distensibility index (DI) and anatomy is shown. Statistically significant differences are indicated. Discordant cases are marked with an *. 3/5 cases a low DI yet no retention had repetitive antegrade contractions, and all 5 had contractility. Both cases of deformity were epiphrenic diverticula. 4/5 cases with retention despite a normal DI had a DI < 3.5 suggesting a borderline obstruction. 3/5 of these cases also had repetitive retrograde contractions. 2/2 cases with an ES >3 despite a normal DI had a DI < 3.5 suggesting a borderline obstruction. 1 of these cases also had repetitive retrograde contractions.

Figure 8.

Outcome analysis tree for retention (A) and Eckardt score (B). A breakdown of patients and % based on maximal EGJ diameter (MxEGJD) and anatomy is shown. Statistically significant differences are indicated. Discordant cases are marked with an *.