Technical problems produced by the Bravo pH test in nonerosive reflux disease patients

A novel placement method of a calibration-free pH capsule for continuous wireless measurement of intragastric pH in horses

BACKGROUND

Current methods to measure intragastric pH in horses have limitations. A wireless capsule has been designed for continuous esophageal pH monitoring in humans.

OBJECTIVES

To (1) determine the feasibility and describe the methodology of measuring intragastric pH wirelessly in horses; and (2) determine attachment duration of the capsules.

ANIMALS

Eleven healthy adult horses.

METHODS

Capsules were attached to squamous and glandular gastric mucosa under gastroscopic guidance, using suture loops and 1 to 4 hemostasis clips. pH was continuously recorded using a wireless recorder in both fed and fasted states. Gastroscopy was performed daily to assess capsule attachment and any mucosal damage. Data were analyzed using commercially available software. Values are reported as median (interquartile range).

RESULTS

Capsules were successfully placed and data obtained in squamous (n = 11) and glandular (n = 7) regions. The overall duration of squamous capsule attachment was 27 hours (15-32); 1 clip (n = 4) was 15 hours (11-20), 2 clips (n = 2) was 20 hours (16-23), 3 clips (n = 4) was 32 hours (30-32), and 4 clips (n = 1) was 33 hours. The overall duration of glandular capsule attachment was 10 hours (8-21); 1 clip (n = 2) was 11 hours (10-13), 2 clips (n = 2) was 19 hours (14-23), 3 clips (n = 2) was 7 hours (7-8), and 4 clips (n = 1) was 158 hours. There was no substantial damage to the gastric mucosa as a consequence of attachment.

CONCLUSIONS AND CLINICAL IMPORTANCE

This novel technique enables the wireless measurement of intragastric pH in horses at known locations under fed and fasted conditions, providing a viable alternative for continuous monitoring in both research and clinical scenarios.

Gastrointestinal devices: common and uncommon foreign bodies

Devices for the gastrointestinal tract are widely available and constantly advancing with less invasive techniques. They play a crucial role in diagnostic and therapeutic interventions and are commonly placed by interventional radiologists, gastroenterologists, and surgeons. These devices frequently appear in imaging studies, which verify their proper placement, identify any complications, or may be incidentally detected. Radiologists must be able to identify these devices at imaging and understand their intended purpose to assess their efficacy, detect complications such as incorrect positioning, and avoid misinterpreting them as abnormalities. Furthermore, many patients with these devices may require MRI, making assessing compatibility essential for safe patient care. This review seeks to provide a succinct and practical handbook for radiologists regarding both common and uncommon gastrointestinal devices. In addition to textual descriptions of clinical indications, imaging findings, complications, and MRI compatibility, the review incorporates a summary table as a quick reference point for key information and illustrative images for each device.

The assessment of patients with non-erosive gastroesophageal reflux disease by using the Bravo® pH monitoring system

Background and aim: Gastroesophageal reflux disease (GERD) is a common disease in the world. GERD is always treated with drugs. The Bravo® wireless pH monitoring system is a good technique. The Bravo® may affect increasing the specificity and sensitivity in the diagnosis of GERD with its 48-hour recording feature. In this study, we aimed to assess the diagnostic performance of the Bravo® pH monitoring system in patients with non-erosive GERD. Materials and Methods: Patients with non-erosive reflux disease (normal endoscopy) whose symptoms persisted after PPI treatment (at least two months) were included in the study. All patients had upper gastrointestinal system endoscopies performed in our clinic between January 2013 and December 2019. All patients had a 48-hour Bravo® wireless pH monitoring record. Results: Twenty-three patients (M: 18 (78.3%; Age: 35.7 ± 11) were included in the study. All patients completed the 2-day recording protocol. During and after the procedure, no patient showed any adverse effects of the Bravo® procedure. We diagnosed GERD in 13 of 23 patients by Bravo® capsule. According to the Bravo® pH-meter recordings; Total time pH < 4 (minute) was 187 ± 190, the total number of refluxes was 90 ± 61, the percentage of time with pH < 4 was 7.1 ± 7.22, the number of long reflux events were 8.1 ± 8, the duration of the longest reflux episode during pH < 4 (minute) was 31 ± 49, the Demeester score was 20.8 ± 19.3 detected. Conclusion: Based on the results of the current study, the Bravo® pH monitoring system is a practical and effective diagnostic technique for non-erosive GERD. Further prospective studies would be useful for comparing the differences between 24-hour and 48-hour pH recording results.

Esophageal pH Capsule Retention

The wireless pH capsule is widely used to evaluate gastroesophageal reflux disease in patients. Common complications include premature capsule detachment, dysphagia, chest pain, and technical malfunctions. We present a 6-year-old boy who presented to our institution with a 2-day history of coffee-ground emesis. A pH capsule was found to be lodged in his distal esophagus 45 days after initial placement. We explore the possible reasons for capsule retention and briefly discuss the safety implications of this finding because we believe that this complication may be underreported.

[The Additional Role of Symptom-Reflux Association Analysis of Diagnosis of Gastroesophageal Reflux Disease Using Bravo Capsule pH Test]

BACKGROUND/AIMS

Since the development of ambulatory esophageal pH monitoring test to diagnose gastroesophageal reflux disease (GERD), several parameters have been introduced. The aim of this study was to assess whether using the symptom index (SI), symptom sensitivity index (SSI), and symptom association probability (SAP), in addition to the DeMeester score (DS), would be useful for interpreting the Bravo pH monitoring test.

METHODS

A retrospective study, which included 68 patients with reflux symptoms refractory to proton pump inhibitor (PPI) therapy who underwent a Bravo capsule pH test between October 2006 and May 2015, was carried out. Acid reflux parameters and symptom reflux association parameters were analyzed.

RESULTS

The median percent time of total pH<4 and DS were 2.90% (interquartile range [IQR] 1.13-6.03%) and 11.10 (IQR 4.90-22.80), respectively. According to the analysis of the day-to-day variation in percent time of total pH<4 (r=0.724) and DS (r=0.537), there was a significant correlation between Day 1 and Day 2. The positive rate of Bravo test according to DS was 27 (39.7%). Although thirty patients experienced symptoms during the test, there were no significant differences of reflux parameters compared with other patients. In the symptom group, 7 patients (23.3%) were identified as having negative DS and an abnormal symptom-related index. There were no significant test-related complications.

CONCLUSIONS

In addition to the analysis of traditional acid parameters of the Bravo capsule pH test, diagnosis of GERD, including reflux hypersensitivity, can be improved by performing an analysis of the symptom-reflux association and of the day-to-day variation.

Bravo® Capsule Aspiration: A Rare Case Report

Bravo® capsule (BC) (Medtronic, Minneapolis, MN) endoscopy is a reliable, viable, and well-tolerated diagnostic modality for resistant gastroesophageal reflux disease (GERD). Common complications of the procedure include early dislodgment, poor transmission, and premature removal due to intractable pain, while aspiration of the capsule is exceedingly rare. This paper reports a case of BC aspiration in a 52-year-old female who presented after being ventilated when her oxygen saturation dropped. The initial chest radiograph revealed that the BC was in the right main bronchus; the site was further elaborated by flexible endoscopy and the capsule was found to be in the right lower lobe bronchus distal to the bronchus intermedius. This was followed by a rigid bronchoscopy and extraction of the capsule with rigid grasper forceps. Although this occurs rarely, immediate endotracheal intubation and ventilator support is the preferred emergency step in such cases until bronchoscopic removal can be performed. 

Evaluation of Gastroesophageal Reflux Disease Using the Bravo Capsule pH System

Gastroesophageal reflux disease (GERD) is a disease predominantly seen in the West but there is a rising trend in Asia. Ambulatory 24-hour catheter-based pH monitoring has been the de facto gold standard test for GERD that correlates symptoms with acid reflux episodes. However, drawbacks such as patients’ discomfort, and catheter displacement render the test as cumbersome and error-prone. The Bravo pH wireless system is designed to be user-friendly and has an added advantage of prolonged pH monitoring. The system is comparable to the catheter-based pH monitoring system in terms of diagnostic yield and symptom-reflux association. Indications include evaluation of patients with refractory GERD symptoms and prior to anti-reflux surgery. Bravo utilizes a wireless pH-sensing capsule with a complete prepackaged system, and a data processing software. The capsule may be positioned indirectly using endoscopic or manometric landmarks or under direct endoscopic guidance. Optimal threshold cut-off values are yet to be standardized but based on available studies, for the Asian population, it may be recommended for total % time pH < 4 of 5.8 over 48 hours. Cost is a limitation but capsule placement is relatively safe although technical failures may be seen in small percentage of cases.

Gastric perforation following endoscopic removal of a Bravo pH capsule in a cat

A 7-year-old domestic shorthair cat was evaluated for hyporexia and weight loss following endoscopic placement of an intragastric pH monitoring device. Physical examination of the cat was unremarkable, and its blood work was notable for a mild hypoalbuminemia. The cat's acute hyporexia and weight loss was attributed to discomfort associated with the intragastric pH monitoring device, as has been reported in humans. Endoscopic removal of the intragastric pH monitoring device resulted in gastric perforation. The cat underwent exploratory laparotomy for surgical resection and repair of the perforated area. To our knowledge, this is the first report of gastric perforation secondary to removal of a Bravo pH capsule. Caution may be advised when considering intragastric pH capsule removal in cats.

Unreported complication of Bravo pH capsule dislodged into the pyriform sinus

We report an unexpected, previously unreported complication of Bravo pH capsule dislodgement. During Bravo pH testing of a 44-year-old man with gastroesophageal reflux disease, we were unable to endoscopically visualize the capsule attached to the esophageal wall after deployment. After multiple attempts to detect the capsule, it was visualized in the left pyriform sinus. As there was significant risk for pulmonary dislodgement, ENT and pulmonary physicians were immediately consulted to review options for safe removal. Ultimately, ENT successfully retrieved the capsule with a foreign body removal forceps. The Bravo pH test is generally a well-tolerated diagnostic tool used to confirm the presence of abnormal esophageal acid reflux. While few complications have been reported, technical difficulties can occur, including poor data reception, misplacement, and early dislodgement. Rarely, more serious complications can occur, ranging from esophageal wall trauma to capsule aspiration. Gastroenterologists performing this procedure should be aware of the low, but non-trivial, risk of complications.

Flexible and capsule endoscopy for screening, diagnosis and treatment

Endoscopy dates back to the 1860s, but many of the most significant advancements have been made within the past decade. With the integration of robotics, the ability to precisely steer and advance traditional flexible endoscopes has been realized, reducing patient pain and improving clinician ergonomics. Additionally, wireless capsule endoscopy, a revolutionary alternative to traditional scopes, enables inspection of the digestive system with minimal discomfort for the patient or the need for sedation, mitigating some of the risks of flexible endoscopy. This review presents a research update on robotic endoscopic systems, including both flexible scope and capsule technologies, detailing actuation methods and therapeutic capabilities. A future perspective on endoscopic potential for screening, diagnostic and therapeutic gastrointestinal procedures is also presented.

The value of early wireless esophageal pH monitoring in diagnosing functional heartburn in refractory gastroesophageal reflux disease

BACKGROUND AND AIMS

It is difficult to differentiate functional heartburn from proton pump inhibitor (PPI) failure. The aims of this study were to assess the role of early wireless esophageal pH monitoring in patients referred with gastroesophageal reflux disease (GERD) and to identify differences in the clinical spectrum among GERD subtypes.

METHODS

We enrolled consecutive referred patients with suspected GERD. After endoscopy on the first visit, all underwent wireless esophageal pH monitoring when off the PPI.

RESULTS

Two hundred thirty patients were enrolled. These patients were classified into a reflux esophagitis group (20, 8.7 %) and a normal endoscopic findings group (210, 91.3 %). Among the 210 patients in the normal endoscopic findings group, 63 (27.4 %) were diagnosed with pathological reflux, 35 (15.2 %) with hypersensitive esophagus, 87 (37.8 %) with normal acid exposure with negative symptom association, and 25 (10.9 %) with test failure. These groups did not differ in age, body mass index, smoking habit, alcohol consumption, symptom severity, quality of life, presence of atypical symptoms, overlap with irritable bowel syndrome, and the frequency of somatization, depression, and anxiety. PPI responses were evaluated in 135 patients. Fifty patients (37.0 %) were not responsive to the 4-week treatment; 26 (19.3 %) were diagnosed with refractory non-erosive gastroesophageal disease, and 24 (17.8 %) with functional heartburn. The demographics and clinical and psychological characteristics did not differ between the two groups.

CONCLUSIONS

Demographic characteristics and symptom patterns alone cannot differentiate functional heartburn from various subtypes of GERD. Wireless esophageal pH monitoring should be considered for the initial evaluation of GERD in the tertiary referral setting.

Wireless oesophageal pH monitoring: establishing values in a multiracial cohort of asymptomatic Asian subjects

BACKGROUND

Wireless oesophageal (Bravo) readings in healthy European and American subjects show varied results. Values in Asians remain unstudied.

AIMS

We performed Bravo studies in healthy Asians to determine if values differed from previously published and identified reflux parameters to differentiate healthy volunteers from patients.

METHODS

Fifty healthy volunteers were recruited between August 2009 and August 2011 to undergo 48 h wireless pH monitoring. Bravo capsule was introduced transorally and placed 6 cm above the squamocolumnar junction. Acid reflux parameters were compared against 41 patients previously evaluated for non-erosive reflux disease.

RESULTS

Five volunteers were excluded. Capsule dislodgement occurred in four and three volunteers on study days 1 and 2 respectively. Forty and 37 volunteers (73% male, mean age 33.0 ± 7.6 years) had interpretable readings at 24 and 48 h, respectively. Percentage of time oesophageal pH<4 in 37 volunteers who completed 48 h recordings was 1.6% (7.5%), 1.5% (6.3%) and 1.9% (5.8%) on days 1, 2 and overall study duration, respectively.

CONCLUSION

Bravo readings in Asians differed from previously published. Percentage of time oesophageal pH<4 on day 2 and DeMeester score on day 2 (95th percentile 22.9) best discriminated healthy volunteers from patients.