Phenotyping patients with borderline elevated esophageal acid exposure.

Acid exposure time (AET) <4% on ambulatory reflux monitoring definitively rules out pathologic gastroesophageal acid reflux, while AET >6% indicates pathologic reflux per the Lyon Consensus, leaving AET of 4-6% as borderline. We aimed to elucidate the borderline AET population and identify metrics that could help differentiate this group. A total of 50 subjects in each group, AET <4, 4-6, and >6% on pH-impedance monitoring between 2015 and 2019, were retrospectively reviewed. In addition to demographic and clinical information, the extracted data included mean nocturnal baseline impedance (MNBI) on reflux study and high-resolution manometry (HRM) parameters and diagnosis. After excluding patients with prior foregut surgery, major esophageal motility disorder, or unreliable impedance testing, a total of 89 subjects were included in the analysis (25 with normal AET < 4%, 38 with borderline 4-6%, 26 with abnormal >6%). MNBI in borderline AET patients was significantly lower compared to normal AET (1607.7 vs. 2524.0 ohms, P < 0.01), and higher than abnormal AET (951.5 ohms, P < 0.01). Borderline subjects had a greater frequency of ineffective esophageal motility (IEM) diagnosis per Chicago classification v3.0 (42.1 vs. 8.0%, P = 0.01), but did not demonstrate any differences compared to abnormal subjects (34.6%, P = 0.56). Patients with borderline AET had an average MNBI that was in between normal AET and abnormal AET. Borderline AET patients also commonly demonstrate IEM on HRM, similar to those with abnormal AET. Our findings can be potentially useful in assigning higher clinical significance for patients found to have borderline AET with concomitant low MNBI and IEM on manometry.

Changes in impedance planimetry metrics predict clinical response to flexible endoscopy in Zenker's diverticulotomy.

Background and study aims Various techniques have been described for flexible endoscopic therapy for Zenker's diverticulum (ZD). Objective methods to assess myotomy effectiveness are lacking. We assessed the utility of impedance planimetry in flexible endoscopic ZD therapies and correlation with a validated symptom score. Patients and methods Patients undergoing endoscopic therapy for symptomatic ZD from February 2019 to March 2020 were included. Intraprocedural impedance planimetry was performed pre- and post-myotomy to assess esophageal diameter and distensibility index (DI). Eating Assessment Tool (EAT)-10 scores were assessed preintervention and post-intervention. Descriptive statistics were calculated. Results Thirteen patients (46 % women; mean age 80 years; 77 % peroral endoscopic myotomy technique) were included. Technical and clinical success was 100 %. No adverse events occurred. At 40 mL and 50 mL, the diameter improved (mean 2.3 mm and 2.6 mm, respectively). At 40 mL and 50 mL, the DI improved (mean 1.0 mm 2 /mmHg and 1.8 mm 2 /mmHg, respectively). EAT-10 scores improved by a mean of 15 points. Mean follow-up was 97 days. Conclusions Intraprocedural impedance planimetry may provide objective data to define success for flexible endoscopic ZD. Further research is required to corroborate these results.

Impact of gastric per-oral endoscopic myotomy on static and dynamic pyloric function in gastroparesis patients.

BACKGROUND: Functional Lumen Imaging Probe (EndoFLIP) tests typically measure static pyloric parameters, but the pylorus exhibits phasic variations on manometry. Dynamic changes in pyloric function have not been quantified using EndoFLIP, and the impact of Gastric Per-Oral Endoscopic Myotomy (G-POEM) on static and dynamic pyloric activity in gastroparesis is unknown. METHODS: EndoFLIP balloon inflation to 30, 40, and 50 mL was performed to measure mean, maximum, and minimum values and variability in pyloric diameter and distensibility before and after G-POEM in 20 patients with refractory gastroparesis. The impact of phasic contractions on these pyloric measures was compared. KEY RESULTS: G-POEM increased mean (P < .0001) and maximum (P = .0002) pyloric diameters and mean (P = .02) and maximum (P = .02) pyloric distensibility on 50 mL EndoFLIP inflation but not intraballoon pressures or minimum diameters or distensibility. Temporal variability of pyloric diameter (P = .02) and distensibility (P = .02) also increased after G-POEM. Phasic coupled contractions propagating from the antrum through the pylorus were observed in 37.5% of recordings; other phasic activity including isolated pyloric contractions were seen in 23.3%. Variability of pyloric diameter and distensibility tended to be higher during recordings with phasic activity. Some pyloric responses to G-POEM were influenced by age, gastroparesis etiology, gastric emptying, and prior botulinum toxin injection. CONCLUSIONS & INFERENCES: Pyloric activity exhibits dynamic changes on EndoFLIP testing in gastroparesis. G-POEM increases maximal but not minimal diameter and distensibility with increased variations, suggesting this therapy enhances pyloric opening but may not impair pyloric closure. Phasic pyloric contractions contribute to variations in pyloric activity.