Esophagogastric junction contractile integral (EGJ-CI) quantifies changes in EGJ barrier function with surgical intervention

Abstract

Background: Esophagogastric junction contractile integral (EGJ-CI) assesses EGJ barrier function on esophageal high resolution manometry (HRM). We assessed EGJ-CI values in achalasia and gastroesophageal reflux disease (GERD) to determine if postoperative EGJ-CI changes reflected surgical intervention.

Methods: Twenty-one achalasia patients (42.8 ± 3.2 years, 62% F) with HRM before and after Heller myotomy (HM) and 68 GERD patients (53.9 ± 1.8 years, 66% F) undergoing antireflux surgery (ARS) were compared to 21 healthy controls (27.6 ± 0.6 years, 52% F). Esophagogastric junction contractile integral (mmHg.cm) was calculated using the distal contractile integral measurement across the EGJ, measured above the gastric baseline and corrected for respiration. Pre and postsurgical EGJ-CI and conventional lower esophageal sphincter pressure (LESP) metrics were compared within and between these groups using non-parametric tests. Correlation between EGJ-CI and conventional LESP metrics was assessed.

Key results: Baseline EGJ-CI was higher in achalasia compared to GERD (p < 0.001) or controls (p = 0.03). Esophagogastric junction contractile integral declined by 59.2% after HM in achalasia (p = 0.001), and increased by 26.3% after ARS in GERD (p = 0.005). End-expiratory and basal LESP decreased by 74.5% and 64.5% with HM, but increased by only 17.8% and 4.3% with ARS. Differences were noted between Dor vs Toupet fundoplication in achalasia (p = 0.007), and partial vs complete ARS in GERD (p = 0.03). Esophagogastric junction contractile integral correlated modestly with both end-expiratory and basal LESP (Pearson's r of 0.8 for all), but was less robust in GERD (0.7).

Conclusions & inferences: Esophagogastric junction contractile integral has clinical utility in assessing EGJ barrier function at baseline and after surgical intervention to the EGJ, and could complement conventional EGJ metrics.

Keywords: antireflux surgery; esophagogastric junction; high-resolution manometry; myotomy.

Figure 1

Measurement of the esophagogastric junction contractile integral (EGJ-CI). The distal contractile integral (DCI) box is placed over the esophagogastric junction covering exactly 3 respiratory cycles, during the initial landmark phase when basal LES metrics are obtained. The recorded value (raw EGJ-CI, in mmHg.cm.sec) is divided by the duration of three respiratory cycles to yield the corrected EGJ-CI in mmHg.cm.

Figure 2

Comparison of lower esophageal sphincter pressure (LESP) metrics and EGJ-CI between achalasia, GERD and controls at baseline (A) and between achalasia and GERD postoperatively (B). Baseline conventional metrics (end expiratory LESP, basal LESP) as well as EGJ-CI were higher in achalasia compared to the other two groups (p≤0.03 for each comparison). Post-operative EGJ-CI strongly trended to be lower in achalasia compared to GERD (p=0.051) but conventional LESP metrics were not different between the two groups.

Figure 2

Comparison of lower esophageal sphincter pressure (LESP) metrics and EGJ-CI between achalasia, GERD and controls at baseline (A) and between achalasia and GERD postoperatively (B). Baseline conventional metrics (end expiratory LESP, basal LESP) as well as EGJ-CI were higher in achalasia compared to the other two groups (p≤0.03 for each comparison). Post-operative EGJ-CI strongly trended to be lower in achalasia compared to GERD (p=0.051) but conventional LESP metrics were not different between the two groups.

Figure 3

Change in esophagogastric junction contractile integral (EGJ-CI) following surgical intervention in achalasia and GERD. All LES metrics declined significantly following Heller myotomy for achalasia (p<0.001 for each comparison). Only EGJ CI augmented significantly following antireflux surgery for GERD (p<0.001).

Figure 4

Differences in esophagogastric junction contractile integral (EGJ-CI) between types of antireflux procedures performed with Heller myotomy (HM) in achalasia, and in GERD. Augmentation of EGJ-CI was more robust following Dor fundoplication with HM (p=0.007 compared with Toupet fundoplication in this setting. Nissen fundoplication in GERD resulted in the highest augmentation of EGJ-CI (p=0.025 compared to Toupet fundoplication in this setting).

Figure 5

Comparison of conventional lower esophageal sphincter pressure (LESP) metrics with esophagogastric junction contractile integral (EGJ-CI). There was excellent correlation between individual LESP metrics (end-expiratory LESP, A; basal LESP, B) and EGJ-CI (Pearson’s r=0.8, p<0.001 for each comparison). Correlation was similar for controls and achalasia (r=0.8–0.9), but less robust for GERD (r=0.7).

Figure 5

Comparison of conventional lower esophageal sphincter pressure (LESP) metrics with esophagogastric junction contractile integral (EGJ-CI). There was excellent correlation between individual LESP metrics (end-expiratory LESP, A; basal LESP, B) and EGJ-CI (Pearson’s r=0.8, p<0.001 for each comparison). Correlation was similar for controls and achalasia (r=0.8–0.9), but less robust for GERD (r=0.7).