Abstract
OBJECTIVE: To assess the suitability of Bama pigs as a model for laryngopharyngeal reflux disease (LPRD) research. METHODS: Sixteen 8-month-old male Bama pigs underwent esophageal manometry to determine the precise anatomical positioning of the upper (UES) and lower esophageal sphincters (LES) relative to the incisor teeth, as well as their respective contraction intensities. The pigs were randomly allocated into three experimental groups (n = 6, 5, 5), with each group subjected to Dx PH-probe monitoring. In Group 1, animals were fasted for 24 hours and water-deprived for 6 hours before undergoing pH monitoring under anaesthesia. Group 2 was anaesthetised two hours post-normal feeding and subsequently monitored. Group 3 also received anaesthesia two hours after eating but were monitored in an awake state. RESULTS: The mean distance from the UES to the incisor teeth was found to be 19.8 ± 1 cm, while the LES was located at 40 ± 2.5 cm. The resting pressure measurements revealed a mean value of 64 ± 12 mmHg for the UES and 20 ± 4 mmHg for the LES in Bama pigs. Laryngopharyngeal pH values across the three groups were 7 ± 0.6, 7 ± 0.5, and 7.4 ± 1.2, respectively, showing no significant differences or reflux events. Similarly, there was no statistically significant difference in the lower oesophageal pH between Group 1 and Group 2. CONCLUSIONS: The Bama pig emerges as a suitable animal model for studying LPRD, given its comparable physiological parameters. The feasibility of establishing a reflux model in Bama pigs and using it to investigate the underlying mechanisms of LPRD is convincingly supported by these findings.