This study aims to enhance the effectiveness of high resolution manometry (HRM) and pH-impedance monitoring metrics in distinguishing between gastro-esophageal reflux disease (GERD) and non-GERD. A retrospective propensity score matching (PSM) study was conducted on 643 patients with GERD symptoms. PSM matched 134 GERD patients with 134 non-GERD controls. Body mass index (BMI), intra-esophageal pressure (IEP) and intra-gastric pressure (IGP) were significantly higher in the GERD group compared to the non-GERD group. BMI was correlated with IEP and IGP positively. IGP was positively correlated with esophagogastric (EGJ) pressure (EGJ-P) in participants with EGJ type 1 and 2, but not in participants with EGJ type 3. BMI was correlated with distal MNBI negatively. Logistic regression showed BMI as an independent risk factor for GERD. Receiver operating characteristic curve (ROC) and decision curve analysis (DCA) showed that BMI adjusted EGJ contractile integral (EGJ-CI) and BMI adjusted MNBI were superior to the corresponding original ones in predicting GERD susceptibility. According to the findings, BMI and IGP are the main factors contributing to the development of GERD. BMI affects IEP through the adaptive response of EGJ-P to IGP. Incorporating BMI into the calculations of EGJ-CI and MNBI can improve their ability in predicting GERD susceptibility.

Clinical practice guidelines drive clinical practice and clinicians rely to them when trying to answer their most common questions. One of the most important position papers in the field of gastro-esophageal reflux disease (GERD) is the one produced by the Lyon Consensus. Recently an updated second version has been released. Mean nocturnal baseline impedance (MNBI) was proposed by the first Consensus to act as supportive evidence for GERD diagnosis. Originally a cut-off of 2292 Ohms was proposed, a value revised in the second edition. The updated Consensus recommended that an MNBI < 1500 Ohms strongly suggests GERD while a value > 2500 Ohms can be used to refute GERD. The proposed cut-offs move in the correct direction by diminishing the original cut-off, nevertheless they arise from a study of normal subjects where cut-offs were provided by measuring the mean value ± 2SD and not in symptomatic patients. However, data exist that even symptomatic patients with inconclusive disease or reflux hypersensitivity (RH) show lower MNBI values in comparison to normal subjects or patients with functional heartburn (FH). Moreover, according to the data, MNBI, even among symptomatic patients, is affected by age and body mass index. Also, various studies have proposed different cut-offs by using receiver operating characteristic curve analysis even lower than the one proposed. Finally, no information is given for patients submitted to on-proton pump inhibitors pH-impedance studies even if new and extremely important data now exist. Therefore, even if MNBI is an extremely important tool when trying to approach patients with reflux symptoms and could distinguish conclusive GERD from RH or FH, its values should be interpreted with caution.

This study evaluated in vivo, an intraoral device against the gold standard esophageal device for gastroesophageal reflux disease (GERD) monitoring. Subjects scheduled for a catheter-based esophageal pH/impedance testing at a gastroenterology clinic were recruited. They were screened using the GerdQ questionnaire, demographics and dental conditions recorded. A prototype intraoral device, consisting of a Bravo™ capsule embedded in an Essix-style retainer fabricated for each subject, monitored intraoral pH. Concurrently, subjects underwent 24-h esophageal pH-impedance monitoring. A self-administered survey elicited the comfort and acceptance of both devices. The study recruited ten adult subjects (23 to 60-years-old) with a median GerdQ score of 9.5 corresponding to a 79% likelihood of GERD. Subjects with severe dental erosion had significantly (p < 0.05) higher acid exposure time and more non-meal reflux events. No adverse events were associated with the intraoral device while one was recorded for the esophageal device. The intraoral device was significantly more comfortable to place, more comfortable to wear, and interfered less with daily routine compared to the esophageal device. Accuracy of the intraoral device ranged between 86.15% and 37.82%. Being more tolerable than traditional esophageal pH monitoring, intraoral pH monitoring may be a useful adjunct for the diagnosis and management of GERD.

BACKGROUND: Mean nocturnal baseline impedance (MNBI) can improve diagnostic accuracy for gastroesophageal reflux disease (GERD), but must be manually calculated and is not routinely reported. We aimed to determine how automated software-derived mean supine baseline impedance (MSBI), a potential novel GERD metric, is related to MNBI.
METHODS: Consecutively obtained pH-impedance studies were assessed. Manually extracted MNBI was compared to MSBI using paired t-test and Spearman\'s correlations.
RESULTS: The correlation between MNBI and MSBI was very high (ρ = 0.966, p < 0.01).
CONCLUSIONS: The ease of acquisition and correlation with MNBI warrant the routine clinical use and reporting of MSBI with pH-impedance studies.

BACKGROUND: Gastro-esophageal reflux (GORD) following sleeve gastrectomy (SG) is a central challenge, and precise indications for revisional surgery or the physiology have not been precisely defined. We aimed to determine whether OAGB performed for reflux post-SG (1) accelerates gastric emptying half-time, (2) reduces the frequency and severity of reflux events, and (3) improves reflux symptoms.
METHODS: We undertook a prospective trial (ACTRN12616001089426). There were 22 participants who underwent measurement before and after revisional surgery with 29 optimal SG (patients with optimal outcome from their primary surgery) as controls. All participants underwent a protocolized nuclear scintigraphy, 24-h pH monitoring, and gastroscopy and completed objective questionnaires.
RESULTS: Trial patients were 90.9% female, age 44.4 years. Conversion from SG to OAGB was at a median of 45.2 ± 19.6 months. Scintigraphy showed an increased rate of gastric emptying post-OAGB 34 (IQR 14) vs 24 (IQR 10.3) min, p-value 0.008, with decreased number of reflux events post-prandially (39 (IQR 13) vs 26 (IQR 7), p-value 0.001). This data correlated with the pH analysis; total acid events substantially reduced post-OAGB 58.5 (IQR 88) vs 12 (IQR 9.4) events, p-value 0.017. Endoscopic findings indicated a reduction in incidence of bile stasis 72.7% vs 40.9% post-OAGB, p-value < 0.00010. Post-OAGB, patients experienced less frequent regurgitation (12 ± 4.1 vs. 5.5 ± 3, p-value 0.012) and reflux (37.1 ± 15.7 vs. 16.8 ± 12.6, p-value 0.003).
CONCLUSIONS: We found OAGB is an effective treatment for reflux associated with delayed gastric emptying post-SG. The likely mechanisms is by, an increase in the rate of gastric clearance and reduced reflux events and overall esophageal acid exposure. This suggests that some forms of post-SG reflux are driven by slower emptying of the residual stomach and are amenable to treatment with drainage above the incisura.

BACKGROUND: Upper gastrointestinal (UGI) symptoms are very common in the general adult population. Dysphagia, heartburn, regurgitation and non-cardiac chest pain are the most common signs. The clinical approach in managing these symptoms starts with upper GI endoscopy in order to exclude inflammatory, neoplastic and fibrotic disorders that involve the esophagus. Upper GI endoscopy is mandatory especially when alarm signs exist. In patients with no structural abnormalities, physiological testing might aid to better understand the origin of the symptoms and to improve management.

OBJECTIVE: The incidence of unresolved postoperative reflux after bariatric surgery varies considerably. Consistent perioperative patient characteristics predictive of unresolved reflux remain unknown. We leverage our institution\'s comprehensive preoperative esophageal testing to identify predictors of postoperative reflux.
METHODS: We performed a single-center retrospective review of adult patients with preoperative reflux symptoms who underwent either vertical sleeve gastrectomy (VSG) or Roux-en-Y gastric bypass (RYGB) from 2015 to 2021. All patients had pH and high-resolution manometry preoperatively. Predictors of postoperative unresolved reflux at 1 year were explored via Fisher\'s exact test, Kruskal Wallis test, and univariate logistic regression.
RESULTS: Unresolved reflux was higher in patients undergoing VSG (n = 60/129,46.5%) vs. RYGB (n = 19/98, 19.4%). Median DeMeester scores were higher (22 vs. 13, p = .07) along with rates of ineffective esophageal motility (IEM) (31.6 vs. 8.9%, p = .01) in the 19 (19.3%) patients with unresolved postoperative reflux after RYGB compared to the resolved RYGB reflux cohort. Sixty (46.5%) of VSG patients had unresolved postoperative reflux. The VSG unresolved reflux cohort had similar median DeMeester and IEM incidence to the resolved VSG group but more preoperative dysphagia (13.3% vs. 2.9%, p = .04) and higher preoperative PPI use (56.7 vs. 39.1%, p = .05). In univariate analysis, only IEM was predictive of unresolved reflux after RYGB (OR 4.74, 95% CI 1.37, 16.4).
CONCLUSIONS: Unresolved reflux was higher after VSG. Preoperative IEM predicted unresolved reflux symptoms after RYGB. In VSG patients, preoperative dysphagia symptoms and PPI use predicted unresolved reflux though lack of correlation to objective testing highlights the subjective nature of symptoms and the challenges in predicting postoperative symptomatology.

BACKGROUND: Esophageal pH-impedance monitoring is a tool for diagnosing gastroesophageal reflux in children. The position of the pH catheter is essential for a reliable reading and the current formulas for calculating catheter insertion length are not completely accurate. The aim of the present study was to develop a new formula for adequate insertion of the pH catheter.
METHODS: A cross-sectional study was conducted on children that underwent pH-impedance monitoring and later radiographic control, to calculate the correct catheter insertion length. The documented variables were age, sex, weight, height, naris to tragus distance, tragus to sternal notch distance, sternal notch to xiphoid process distance, and initial insertion length determined by the Strobel and height interval formulas. A multivariate regression analysis was carried out to predict the final insertion length. Regression ANOVA and Pearson\'s adjusted R-squared tests were performed.
RESULTS: Forty-five pH-impedance studies were carried out, 53% of which were in males. The age and weight variables were not normally distributed. In the initial regression model, the variables that did not significantly correlate with the final insertion length were: sex (P 0.124), length determined by the Strobel or height interval formulas (P 0.078), naris to tragus distance (P 0.905), and tragus to sternal notch distance (P 0.404). The final equation: 5.6 + (height in cm * 0.12) + (sternal notch to xiphoid process distance * 0.57) produced an R2 of 0.93 (P 0.000).
CONCLUSIONS: This formula can be considered a valid option for placement of the pH-impedance monitoring catheter in pediatrics.

BACKGROUND: Post-reflux swallow-induced peristaltic wave index (PSPWI) and mean nocturnal baseline impedance (MNBI) are novel parameters reflect esophageal clearance capacity and mucosal integrity. They hold potential in aiding the recognition of gastroesophageal reflux-induced chronic cough (GERC). Our study aims to investigate their diagnostic value in GERC.
METHODS: This study included patients suspected GERC. General information and relevant laboratory examinations were collected, and final diagnosis were determined following guidelines for chronic cough. The parameters of multichannel intraluminal impedance-pH monitoring (MII-pH) in patients were analyzed and compared to explore their diagnostic value in GERC.
RESULTS: A total of 186 patients were enrolled in this study. The diagnostic value of PSPWI for GERC was significant, with the area under the working curve (AUC) of 0.757 and a cutoff value of 39.4%, which was not statistically different from that of acid exposure time (AET) (p > 0.05). The combined diagnostic value of AET > 4.4% and PSPWI < 39.4% was superior to using AET > 4.4% alone (p < 0.05). Additionally, MNBI and distal MNBI also contributed to the diagnosis of GERC, with AUC values of 0.639 and 0.624, respectively. AET > 4.4% or PSPWI < 39.4% is associated with a 44% reduction in missed diagnoses of non-acid GERC compared to AET > 6.0% or symptom association probability (SAP) ≥ 95%, and may be more favorable for identifying GERC.
CONCLUSIONS: The diagnostic value of PSPWI for GERC is comparable to that of AET. Combining PSPWI < 39.4% or AET > 4.4% can improve the diagnostic efficiency by reducing the risk of missed diagnoses in cases where non-acid reflux is predominant. Distal MNBI and MNBI can serve as secondary reference indices in the diagnosis of GERC.

OBJECTIVE: To evaluate the efficacy of distal esophageal mean nocturnal baseline impedance (MNBI), a general marker of esophageal mucosal barrier integrity, in predicting laryngopharyngeal reflux (LPR) and symptomatic response to acid reflux therapy.
METHODS: This retrospective study analyzed 173 patients who presented with symptoms of laryngopharyngeal reflux and underwent 24-h multichannel intraluminal impedance-pH (MII-pH) testing. Mean nocturnal baseline impedance values were calculated and assessed for their association and ability to predict LPR symptoms, MII-pH results, treatment response, and other markers of LPR.
RESULTS: Notably, 153 of the 173 patients were tested off acid suppression medication and included in statistical analysis. Based on the MII-pH probe data, 108 (71%) patients had LPR, 8 (5%) had gastroesophageal reflux disease (GERD), and 37 (24%) were without pathologic reflux. Distal esophageal MNBI of LPR patients was significantly lower in LPR patients than patients with negative studies (1332 ± 94.8 vs. 2158 ± 173.5, p = 0.001). Among 118 patients who trialed antireflux therapy, a distal esophageal MNBI cutoff value of <1580 Ω was an independent predictor of treatment response (OR = 4.148 [1.877-9.189]). This value better predicted improvement with antireflux therapy for LPR than other objective MII-pH probe data, which were not independent predictors of treatment response.
CONCLUSIONS: Distal esophageal MNBI values may have value in the diagnosis of LPR and potentially predict medication responsiveness in LPR patients.
METHODS: 3 Laryngoscope, 134:4071-4077, 2024.