Bolus exposure as a novel predictor of postoperative symptom resolution after laparoscopic Nissen fundoplication: a two-institutional retrospective cohort study

Abstract

Background: Even in the absence of definite evidence of pathological acid reflux, antireflux surgery (ARS) can still effectively improve gastroesophageal reflux symptoms. Nonetheless, predicting postoperative reflux symptom improvement has been primarily dependent on acid-based parameters. No objective index reflecting both acid and non-acid reflux was identified to select ARS candidates. Materials and methods: Prospectively collected data of 121 patients with gastroesophageal reflux disease (GERD), who underwent laparoscopic Nissen fundoplication from two institutions, were retrospectively reviewed. The patients reported preoperative and postoperative GERD symptoms using the Korean version of the GERD questionnaire, along with the gastroesophageal reflux disease-health-related quality of life (GERD-HRQL). The patients assessed for reflux symptoms using bolus exposure, acid exposure time (AET), and DeMeester score (DMS) as measurements were selected. For each reflux parameter, its association, correlation, and predictive capacity of the degree of postoperative symptom resolution were analyzed using chi-squared tests, point-biserial correlations, logistic regression analyses, and receiver operating characteristic curve analyses. Results: 72 patients were eligible for this study. Bolus exposure was superior to the other parameters in terms of the degree of association and correlation with resolution of typical symptoms. Bolus exposure also showed a higher diagnostic accuracy in predicting the resolution of epigastric pain (area under the curve [AUC]=0.723, P=0.013) and regurgitation (AUC=0.981, P<0.001). Secondary analyses were performed in patients without pathological reflux, defined as the DMS-negative (DMS<14.7) or AET-negative (AET<6%) groups. In the secondary analyses, bolus exposure showed considerable diagnostic accuracy with statistical significance for all typical symptoms in both in the DMS-negative (heartburn: AUC=0.717, P=0.025; epigastric pain: AUC=0.717, P=0.025; regurgitation: AUC=0.975, P<0.001) and AET-negative (heartburn: AUC=0.681, P=0.045; epigastric pain: AUC=0.749, P=0.009; regurgitation: AUC=0.975, P<0.001) groups. Conclusion: Bolus exposure, a parameter of total reflux, was superior to AET or DMS in defining candidates for ARS. Further studies investigating the surgical indications for ARS in patients with non-acid reflux using bolus exposure are required.