No abstract available.
Gastroesophageal Reflux*

Background/Aims: Cholecystokinin (CCK) administration has been shown to reduce lower esophageal sphincter (LES) pressure in normal subjects in manometric studies. Functional luminal imaging probe (FLIP) panometry offers a method to assess esophageal motility in response to sustained distension though mechanisms related to this response remain unexplored. The aim of this study is to evaluate the effect of CCK-8 on the esophageal response to distension in asymptomatic volunteers using FLIP. Methods: Esophageal response to distension was studied in 7 asymptomatic volunteers (mean age ± SD [27 ± 2]; 86% female) before and after CCK-8 administration in a crossover study design. During sedated endoscopy, FLIP was performed twice with CCK-8 administered via intravenous push in one of 2 protocols: during filling (n = 4) or during emptying (n = 3). Esophagogastric junction distensibility index (EGJ-DI) at 60 mL fill volume and esophageal body contractile response patterns were analyzed. Results: During the baseline FLIP study, all subjects had a contractile response with repetitive antegrade contractions both before and after CCK-8 administration. However, a sustained LES contraction or a sustained occluding contraction with esophageal shortening was observed in all subjects in the filling protocol, but in none during the emptying protocol. EGJ-DI was similar before and after CCK-8 during both filling (4.7 ± 1.9 mm2 /mmHg vs 4.3 ± 1.8 mmmm2 /mmHg) and emptying protocol (7.5 ± 1.4 mmmm2 /mmHg vs 6.9 ± 0.6 mmmm2 /mmHg). Conclusion While EGJ-DI appeared unaffected by CCK-8 administration in asymptomatic volunteers, CCK induced spastic-reactive contractions of the LES during distention suggesting that exogenous CCK interferes with normal LES relaxation during secondary peristalsis.

Background/Aims: This study aimed to develop a diagnostic tool using machine learning to apply functional luminal imaging probe (FLIP) panometry data to determine the probability of esophagogastric junction (EGJ) obstruction as determined using the Chicago Classification version 4.0 (CCv4.0) and high-resolution manometry (HRM). Methods: Five hundred and fifty-seven adult patients that completed FLIP and HRM (with a conclusive CCv4.0 assessment of EGJ outflow) and 35 asymptomatic volunteers (“controls”) were included. EGJ opening was evaluated with 16-cm FLIP performed during sedated endoscopy via EGJ-distensibility index and maximum EGJ diameter. HRM was classified according to the CCv4.0 as conclusive disorders of EGJ outflow or normal EGJ outflow (timed barium esophagram applied when required and available). The probability tool utilized Bayesian additive regression treesBART, which were evaluated using a leave-one-out approach and a holdout test set. Results: Per HRM and CCv4.0, 243 patients had a conclusive disorder of EGJ outflow while 314 patients (and all 35 controls) had normal EGJ outflow. The model accuracy to predict EGJ obstruction (based on leave-one-out/holdout test set, respectively) was 89%/90%, with 87%/85% sensitivity, 92%/97% specificity, and an area under the receiver operating characteristic curve of 0.95/0.97. A free, opensource tool to calculate probability for EGJ obstruction using FLIP metrics is available at https://www.wklytics.commgi/prob_flip.html. Conclusions Application of FLIP metrics utilizing a probabilistic approach incorporates the diagnostic confidence (or uncertainty) into the clinical interpretation of EGJ obstruction. This tool can provide clinical decision support during application of FLIP Panometry for evaluation of esophageal motility disorders.