The correlation between gastric bubble size and laryngopharyngeal reflux pattern in patients with laryngopharyngeal reflux disease

Objective To investigate the correlation between gastric bubble size and laryngopharyngeal reflux pattern in patients with laryngopharyngeal reflux disease(LPRD). Methods A total of 52 LPRD patients who underwent Dx-pH monitoring and anteroposterior chest radiography at the same time from February 2016 to November 2018 were retrospectively studied. Patients were devided into three position-related groups according to the Ryan score of upright and supine: isolated upright reflux(IUR), isolated supine reflux(ISR) and bipositional reflux(BR) groups. In addition, 13 healthy volunteers with negative pH monitoring were selected as the control group. Gastric bubble size and pH monitoring data among the four groups were compared. SPSS 24.0 was used for statistical analysis. Results In all the 52 patients, 35 cases (67.3%) were classified as IUR, 9 cases (17.3%) as ISR, and 8 cases (15.4%) as BR. The height of gastric bubbles in the four groups were: IUR (26±14) mm, ISR (9±8) mm, BR (20±13) mm, control (17±15) mm, and statistical difference was found among the four groups(P=0.004). Post Hoc Multiple Comparisons found that IUR group had statistical difference between ISR group and control group (P=0.001, P=0.034 respectively). There was no statistical difference of gastric bubble width and area among the four groups(P=0.340, P=0.186 respectively). The ROC curve of the gastric bubble height with isolated upright and supine reflux patterns was obtained, and the optimal cutoff value of the gastric bubble height was 11 mm. Accordingly, we divided the patiens into two groups with high and low gastric bubble. LPRD reflux pattern distribution was significantly different between the two groups(P<0.001). The comparison of reflux parameters in pH monitoring also showed that the supine reflux parameters in the lower group were significantly higher than those in the higher group, and the upright reflux parameters in the higher group were significantly higher than those in the lower group(P<0.001). Conclusions The height of gastric bubble is significantly correlated with the reflux patterns in LPRD patients. The gastric bubble of patients with IUR is significantly higher than that of patients with ISR. Taking 11 mm as the cutoff value, patients with higher gastric bubble are more prone to upright laryngopharyngeal reflux, while those with lower gastric bubble are more prone to supine laryngopharyngeal reflux. Key words: Laryngopharyngeal reflux; Posture; pH monitoring; Radiography, thoracic