In vitro and in vivo evaluation of a novel wired transmission pH-combined photographic catheter for ambulatory gastroesophageal reflux monitoring (with videos)

Twenty-four-hour pH-impedance monitoring is an important diagnostic approach for gastroesophageal reflux disease (GERD). Reflux monitoring results cannot be synchronized with ambulatory motility imaging of the esophageal sphincter. We have designed a novel wired transmission pH-combined photographic catheter (WT-CPC) for the synchronous acquisition of reflux image and pH. Different patterns of reflux events were simulated to perform in a porcine gastroesophageal reflux model in vitro. The live porcine model of gastroesophageal reflux was established in three Bama pigs. Monitoring was conducted with the WT-CPC and pH-impedance catheter simultaneously. Measurements included the number and proportion of reflux events, as well as acid exposure time (AET). The detection rates of WT-CPC for distal and horizontal acid reflux events were significantly higher compared to those of pH-impedance catheters (100% vs. 14.29%, 100% vs. 57.14%, P < 0.05). There was no significant difference between the two methods in proximal acid reflux events (P = 0.217). Regarding mixed reflux events, WT-CPC exhibited higher detection rates for distal events than pH-impedance catheter (100% vs. 42.86%, P < 0.05). However, there was no significant difference between the two methods for proximal reflux events (P > 0.05). Both methods showed similar results for horizontal reflux events. A porcine gastroesophageal reflux model was successfully established and utilized for reflux monitoring. A total of 28 episodes of reflux were detected within 6.5 min. The detection rate achieved by WT-CPC for reflux events was significantly higher than that obtained by pH-impedance (100% vs. 78.57%, P = 0.023). The WT-CPC has demonstrated reflux monitoring capabilities in an isolated reflux organ model. It also showed good operability and performance in the porcine model. The WT-CPC holds promising potential to provide valuable diagnostic evidence for GERD.