Introduction

Prolonged wireless pH monitoring is the preferred diagnostic tool in unproven GERD when available.1 The Bravo system is better tolerated and increases the diagnostic yield compared to 24-hour transnasal catheter studies.2, 3 A novel system, Alpha, uses a stitch rather than a pin to attach the capsule to the esophageal wall. It stores data temporarily inside the capsule before transmission to the recorder and has been introduced in the United States and worldwide. We aim to compare the two systems with respect to the duration of attachment and patient tolerability.

Aims & Methods

We aim to compare the two systems with respect to the duration of attachment and patient tolerability. Three hundred and ninety-nine patients who underwent prolonged wireless pH monitoring at a regional esophageal center from November 2020 to October 2022 were prospectively studied. The clinical indications for wireless pH studies were set out in published guidelines, and patients followed the same standard procedures. The total capsule retention time and duration of artifacts were measured in minutes. A complete day was defined as more than 20 hours of attachment. Patients completed a previously validated tolerability questionnaire, which included symptoms graded on a Likert scale.³

Results

Two hundred and two symptomatic patients (mean age 47 (18-82) years, 65% F) underwent wireless Alpha, and 197 patients (mean age 48 (18-81) years, 72% F) underwent wireless Bravo catheter-free pH monitoring. Capsule attachment for 96, 72, and 48 hour studies were obtained in 184 (91%), 11 (5.4%), and 3 (1.5%) patients who received Alpha studies, respectively, and in 149 (75.6%), 22 (11%) and 16 (8%) patients who received Bravo studies. No complications occurred with either method (capsule retention, bleeding, perforation). The total capsule retention time was longer in patients receiving the Alpha system when compared to the Bravo system (mean 5560 minutes vs 5194 minutes, p < 0.00001). The Bravo system recordings had more artifacts than Alpha (mean 272 minutes vs 133 minutes, p<0.00001). In patients who achieved a 96-hour study, there were no significant differences in patient tolerability and acceptance between the two systems across all domains (table 1). One hundred and fifteen out of 126 (91%) would recommend Alpha, and 83 out of 91 (91%) patients would recommend Bravo to another patient (p=0.7).

Table 1

Question	n	Alpha 96 hours	n	Bravo 96 hours	p value
Overall experience of the system	127	3.62	89	3.89	0.08
Chest pain	130	3.4	94	3.37	0.7
Swallowing difficulty	130	3.33	94	3.62	0.1
Eating feel different	130	3.27	93	3.36	0.6
Restriction daily activities	128	3.7	93	4.01	0.1
Throat discomfort	130	3.32	94	3.35	0.9

Values are presented as n, number of patients; Alpha and Bravo mean scores.

Conclusion

Both wireless pH monitoring systems had excellent tolerability and low capsule detachment rates before 96 hours. The Alpha system had a lower premature detachment rate, lower artifacts and similar tolerability when compared with the Bravo system.

References

1. Gyawali CP, Yadlapati R, Fass R, et al. Updates to the modern diagnosis of GERD: Lyon consensus 2.0. Gut 2023.
2. Sweis R, Fox M, Anggiansah A, Wong T. Prolonged, wireless pH-studies have a high diagnostic yield in patients with reflux symptoms and negative 24-h catheter-based pH-studies. Neurogastroenterol Motil 2011;23:419-26.
3. Sweis R, Fox M, Anggiansah R, et al. Patient acceptance and clinical impact of Bravo monitoring in patients with previous failed catheter-based studies. Aliment Pharmacol Ther 2009;29:669-76.

Disclosure

No co

Introduction

The definition of actionable GERD according to the Lyon v2.0 Consensus in patients with inconclusive diagnosis of GERD (acide exposure time [AET] that ranges among 4 and 6%) requires adjunctive metrics such as mean nocturnal baseline impedance (MNBI), total number of reflux events and reflux/symptom association (RSA) indices.

Aims & Methods

The aim of this study was to identify patients most likely to have a positive metrics on prolonged 96 hours wireless pH monitoring (PWPM) among patients with inconclusive AET values on 24 hours pH-impedance monitoring (MII-pH) off PPI. Secondary aim was to identify other MII-pH parameters predictive of GERD diagnosis.
This was a retrospective study that collected a series of patients with typical GERD presentation. All patients underwent:

• Endoscopy, to exclude the presence of erosive esophagitis (grade B or higher according to Los Angeles classification);
• Esophageal HRM to rule out motility disorders and calculate: esophago-gastric junction contractile integral (EGJ-CI), esophagogastric junction (EGJ) morphology, and Milan Score.
• MII-pH monitoring to assess AET values, total reflux events, MNBI, RSA and Lyon Score.
• PWPM performed for 96 hours within 1 month after MII-pH.
• Treatment (PPI) response was evaluated with VAS scale during follow-up.

Patients were categorized into 2 different groups: those with vs. without conclusive GERD on PWPM. MII-pH and HRM parameters were compared between the two groups.

Results

51 consecutive patients (24 female; median age 51yrs) were included: 15 patients (8 female, 49yrs, BMI 22.8) had non-conclusive PWPM for GERD (negative), while GERD was confirmed (positive) in 36 patients (16 female, 53yrs, BMI 26.8). There were no significant demographic differences. Prevalence of heartburn and regurgitation were comparable in both groups. Patients with confirmed GERD were more likely to respond to PPI treatment (positive 69% vs negative 59%, p=0.014).
Patients with confirmed GERD on PWPM had a higher AET (p<0.001), total reflux events (p < 0.001), and lower MNBI (p < 0.001) on MII-pH; lower EGJCI, and higher prevalence of hiatal hernia (p<0.001) on HRM; higher Milan SCORE (p < 0.001), and higher Lyon Score (p<0.01) compared to negative PWPM. See Table 1.

	Negative PWPM 96h (15)	Positive PWPM 96h (36)	P
PPI response (VAS)	59 (39, 69)	59 (39, 69)	0.014
Hiatal Hernia	0 (0%)	18 (50%)	<0.001
EGJ-CI	63 (46, 87)	20 (11, 30)	<0.001
MILAN SCORE	48 (42, 53)	196 (173, 234)	<0.001
AET (MIIpH)	1.60 (1.10, 2.90)	5.20 (3.75, 5.85)	<0.001
N REFLUX	25 (19, 29)	44 (36, 54)	<0.001
Symptom Index (+)	0 (0%)	10 (28%)	0.024
MNBI	2871 (2269, 3165)	1055 (910, 1247)	<0.001
LYON SCORE	1.00 (0.00, 2.00)	5.00 (3.00, 6.00)	<0.001

ROC analysis showed that MNBI is the strongest predictor of GERD (AUC 1.0), followed by the Milan (AUC 0.99, Sens 100%, Spec 93%) and Lyon Scores (AUC 0.97, Sens 80%, Spec 100%), total number of reflux events (AUC 0.9, Sens 86%, Spec 93%)
A subgroup of 13 patients (7 female) with an AET<4% but MNBI values <1500 Ohms on MII-pH, all (100%) were confirmed as having GERD on 96h PWPM.

Conclusion

We demonstrate that a low MNBI value on MII-pH is the strongest predicting factor of conclusive GERD diagnosis in patients with borderline or normal AET values. A sub-group of patients with AET <4% but very low MNBI (<1500 Ohms) on MII-pH showed conclusive GERD during subsequent 96 hour PWPM, establishing its longitudinal role in confirming reflux disease.

Disclosure

Conference Speech: Reckitt Benckiser; Malesci; Dr Falk, PharmaLine, AlfaSigma, Sanofi-Genzyme.
Advisory Board: Dr Falk; Astra Zeneca; Sanofi Genzyme, AlfaSigma
Research grant: Dr Falk; Sanofi Genzyme

Introduction

Eosinophilic esophagitis (EoE) and gastroesophageal reflux disease (GERD) may coexist. The role of GERD in histologically PPI (proton pump inhibitors)-refractory (PPI-R) EoE has been poorly investigated.

Aims & Methods

We characterized ambulatory reflux monitoring findings and heartburn outcomes in PPI-R EoE patients undergoing 96-h wireless pH monitoring (WPM) or 24-h pH-impedance (MII-pH). In this international study conducted in two EoE referral centres, we enrolled consecutive patients with EoE who did not achieve histological remission with PPIs (≥15 eosinophils/high-power field) and subsequently underwent off-PPIs reflux monitoring. Demographics, symptoms, medical history, endoscopy findings at index endoscopy, and heartburn resolution following a 12-week course of PPI were retrospectively reviewed. Acid exposure time (AET), number of refluxes, and symptoms index and association probability (SI/SAP) were calculated for MII-pH and WPM. Mean nocturnal baseline impedance and post-reflux swallowed induced peristaltic wave index were also calculated for MII-pH. Validated diagnostic thresholds for reflux monitoring and Rome IV criteria were used to formulate each diagnosis. Data are described as median and interquartile range (Q1-Q3) or as counts and percent. Kruskal-Wallis Rank Sum Test was used for continuous data, and Pearson’s Chi-Square test and Fisher’s exact test for counts. Significance threshold was p<0.05.

Results

Among 73 included patients, 54.8% (n=40) had MII-pH, and 45.2% (n=33) had WPM. The prevalence of conclusive GERD was 34.2% (25/73). Among those with normal AET (65.7%, 48/73), 20.8% had positive SI/SAP, while 79.2% had negative SI/SAP. Conclusive GERD was more frequent on WPM (48.5% vs 22.5%, p=0.02), while absence of GERD was more frequent on MII-pH (77.5% vs 51.5%, p=0.02). There was no difference in the prevalence of SI/SAP positivity between MII-pH and WPM. Heartburn was reported in 76.0% of GERD patients and in 66.6% of those without GERD (p=0.41). Patients with GERD and those without GERD received similar doses of PPIs. Among the 28 patients who were assessed for heartburn resolution, those with normal AET combined with SI/SAP positivity had similar response to PPIs compared to those with GERD (60.0% vs 61.1%; p>0.99).

Conclusion

1. Among PPI-R EoE, only one third has GERD, suggesting that an abnormal AET has a limited role in PPI refractoriness. 2. Heartburn response to PPIs does not predict conclusive GERD in patients with EoE. 3. Although per Rome IV criteria EoE should be ruled out to diagnose reflux hypersensitivity, a proportion of EoE patients with a normal AET has positive symptom-reflux correlation suggesting a possible overlap. In this setting, PPIs provided heartburn resolution in most patients regardless of histologically active EoE.

	Conclusive GERD (25)	No GERD evidence (48)	p value
Age at diagnosis	45 (31-51)	33 (28-41)	0.03
Male sex (n)	64.0%	68.7%	0.68
Heartburn	76.0%	66.6%	0.41
Dysphagia	96.0%	88.0%	0.41
Chest Pain	12.0%	12.0%	>0.99
Nausea/dyspepsia/abdominal pain	8.0%	8.3%	>0.99
Food Impaction	28%	38%	0.42
PPI dose (mg)	40 (32-80)	40 (40-80)	0.66
Number of patients with heartburn response to PPIs	61.1%	60.0%	>0.99

Introduction

Dysphagia is a possible complication of anti-reflux surgery. Whether absent peristalsis on pre-operative esophageal high-resolution manometry (HRM) increases the risk of post-operative dysphagia is unclear.

Aims & Methods

We compared dysphagia and gastro-esophageal disease (GERD) outcomes in patients with absent peristalsis and normal motility undergoing anti-reflux surgery. We enrolled consecutive patients with heartburn and proven GERD on pH-impedance monitoring undergoing Nissen or Toupet fundoplication. All patients underwent pre-operative HRM and pH-impedance monitoring, which were assessed according to Chicago Classification v4.0 and Lyon Consensus, respectively. Age, sex, presence of dysphagia, pH-impedance, and HRM findings were recorded pre-operatively. Post-operatively, all patients completed the following questionnaires: hospital odynophagia & dysphagia questionnaire (HODQ), reflux symptoms index (RSI), reflux disease questionnaire (RDQ), and the GERD-health related quality of life (GERD-HRQL). Data are described as median and interquartile range (Q1-Q3) or as counts and percent. Kruskal-Wallis Rank Sum Test was used for continuous data, and Pearson’s Chi-Square test and Fisher’s exact test for counts. Significance threshold was p<0.05.

Results

Fifty-seven consecutive patients were included, 27 (47.3%) with absent peristalsis (group A) and 30 (26.3%) normal motility (Group B). Nissen fundoplication was performed in 67% of group A and in 90% of group B, while Toupet fundoplication was performed in 33% of group A and 10% of group B. The two groups were comparable in age, sex, and prevalence of pre-operative dysphagia. Significantly more patients from group B underwent Nissen fundoplication (p=0.03). The overall median time interval between the surgery and questionnaires was 28 months (9-48), without significant differences between the groups. The scores of all the post-operative symptomatic outcome measures were comparable between the two groups. These results remained consistent even when only patients undergoing Nissen fundoplication were included in the analysis.

Conclusion

Patients with absent peristalsis do not have an increased risk of post-operative dysphagia and have similar GERD outcomes compared to patients with normal esophageal motility. Absent peristalsis on HRM should not be considered a contraindication for anti-reflux surgery in patients with proven GERD at pH-impedance.

Introduction

Duodenogastroesophageal reflux (DGER), or bile reflux, has gained renewed interest due to the increasing number of bariatric surgeries (BS) performed. Anatomical modifications after BS may predispose patients to reflux. Revisional bariatric surgery (RBS) is indicated for inadequate weight loss or refractory symptoms.

Aims & Methods

This study aimed to evaluate the diagnostic accuracy of pH-impedance (pH-Z) monitoring in detecting DGER, using spectrophotometric bilirrubin (Bilitec2000) as the clinical reference standard. This prospective study included consecutive patients with a history of sleeve gastrectomy (SG) referred for preoperative evaluation prior to RBS between October 2023 and February 2025. All patients underwent simultaneous 24-hour pH-Z monitoring and Bilitec2000 monitoring while off proton pump inhibitors (PPIs). Patients followed a standardized white semiliquid diet. Gastroesophageal reflux disease (GERD) was diagnosed according to the Lyon 2 Consensus. Pathological bile reflux was defined as a total bilirubin absorbance ≥ 0.14 for ≥ 1.9% of the monitoring time.

Results

Fifty-three patients were enrolled [38 (71.7%) female, median age 48 years (IQR 43 – 55), median BMI 37.3 Kg/m² (IQR 34.1 – 41.3)]. Reason for RBS evaluation included
inadequate weight loss (39.6%) refractory reflux symptoms (32.1%), both (24.5%) and other indications (3.5%). GERD was diagnosed in 31 patients (58.5%) and 21 (39.6%) had pathological bile reflux. Erosive GERD according to Los Angeles classification was identified in 10 patients (19.6%). The area under the curve for non-acid reflux episodes detected by pH-z in diagnosing DGER was 0.61 (CI 95% 0.44 - 0.78), with an optimal cutoff of 85 episodes (sensitivity: 38.1% (CI 95% 20.8 – 59.1); specificity of 93.6% (CI95% 79.9 – 98.3). A moderate correlation was found between non-acid reflux and bile reflux (r = 0.38, p=0.005). However, GERD was not associated with increased bile exposure time (1.4% (IQR 0.3 – 9.5) vs 1.3% (IQR 0.0 – 4.8), p=0.262), nor was this association observed in those with erosive esophagitis (1.9%, IQR 0.4 – 9.5 vs 1.4% IQR 0.0 – 5.8; p=0.914).

Conclusion

Approximate 40% of SG patients undergoing RBS evaluation had pathological bile reflux, which was not linked to GERD or erosive esophagitis. Despite a moderate correlation between bile and non-acid reflux episodes, pH-z monitoring failed to reliably detect DGER and should not be considered a substitute for spectrophotometric bilirrubin concentration monitoring.

References

- Basnayake C, Geeraerts A, Pauwels A, et al. Systematic review: duodenogastroesophageal (biliary) reflux prevalence, symptoms, oesophageal lesions and treatment. Aliment Pharmacol Ther. 2021;54(6):755-778. doi:10.1111/apt.16533.
- Eldredge TA, Bills M, Myers JC, Bartholomeusz D, Kiroff GK, Shenfine J. HIDA and Seek: Challenges of Scintigraphy to Diagnose Bile Reflux Post-Bariatric Surgery. Obes Surg. 2020;30(5):2038-2045. doi:10.1007/s11695-020-04510-7