Successful oesophageal pH monitoring with a catheter-free system

Use of Preoperative Endoscopic Capsule-Based pH Testing Before Bariatric Surgery

BACKGROUND

Vertical sleeve gastrectomy is the most performed bariatric operation in the US; however, a significant number of patients suffer from persistent or new-onset reflux. No consensus for objective preoperative evaluation in these patients exists. We compared capsule-based pH testing vs GERD symptom scoring to determine extent of preoperative GERD to aid in procedure selection for bariatric surgery.

STUDY DESIGN

An IRB-approved retrospective review of consecutive patients at a single institution was performed from April 2021 to December 2022. During initial consultation for bariatric surgery, a validated GERD symptom subjective survey was administered. All patients demonstrating interest in sleeve gastrectomy or had a history of reflux underwent upper endoscopy with capsule-based pH testing.

RESULTS

Sixty-two patients underwent preoperative endoscopy with capsule-based pH testing and completed GERD symptom assessment survey(s). Median BMI was 43.4 kg/m 2 and 66.1% of patients were not taking a proton-pump inhibitor before performance of pH testing. There was negligible linear association between the objective DeMeester score obtained by capsule-based pH probe and GERD symptom survey scores. Median GERD symptom survey scores did not differ between patients with and without a diagnosis of GERD based on pH testing (all p values >0.11).

CONCLUSIONS

An objective method for identifying severe GERD in the preoperative assessment may aid in the decision tree for procedure selection and informed consent process. Patients with significant preoperative GERD may be at higher risk for future GERD-related sleeve complications. Capsule-based pH testing may prove to be superior to subjective symptom scoring systems in this patient population.

Patient adverse events and technical failures with the bravo capsule pH system: insights from the MAUDE database

BACKGROUND

The BRAVO pH monitor system can benefit patients with ongoing GERD symptoms despite treatment and/or atypical symptoms. We aim to investigate the number and type of complications associated with the BRAVO pH capsule.

METHODS

From April 2016 through February 2021, we analyzed post-marketing surveillance data from the FDA Manufacturer and User Facility Device Experience (MAUDE) database.

RESULTS

During the study period, approximately 1,651 reports were identified with 2391 cases associated with a device failure, and 254 reporting a patient-related adverse event. Most device complications were due to aspiration n = 153), followed by reported pain (n = 79), injury (unspecified) (n = 63), and additional radiologic imaging (n = 44). Laceration and bleeding accounted for 29 and 19 cases. Furthermore, three patients suffered perforation. Most device failures were due to loss or failure of the Bravo capsule to bond or adhere to the esophageal mucosa as planned (n = 1269), followed by an activation or positioning failure (n = 972), premature detachment of device (n = 284), and failure of the device to record or transmit data (n = 158).

CONCLUSIONS

Findings from the MAUDE database highlight the risk of aspiration, hemorrhage/bleeding, perforation, injury, and retention as potential complications of BRAVO capsule placement.

Developments in Gastroesophageal Reflux Disease over the Last 40 Years

BACKGROUND

The last 40 years have seen a remarkable change in our understanding of reflux disease.

SUMMARY

These changes encompass disease definition and impact, pathophysiology, diagnostic testing, regulatory oversight of clinical trials, pharmacotherapy, endoscopic, and surgical treatment. We have also seen a number of promising therapies fail.

KEY MESSAGES

The future holds the promise of further advances. Adaptive artificial intelligence will take over diagnostics in manometry and pH impedance testing and patient-driven outcomes may be changed by interactions with artificial intelligence rather than humans. Changes in chip technology will allow higher resolution chips to be carried on smaller devices making extra-esophageal areas where reflux may play a role more accessible to prolonged observation and testing.

Nissen fundoplication and dyspeptic symptoms: is the water load test useful?

BACKGROUND

The water load test is a simple, cheap and standardized method to evaluate gastric distension and gastric motility responses. We have previously shown that in patients with mild erosive or non-erosive esophagitis this test is frequently abnormal, suggesting an altered gastric function. The aim was to evaluate the water load test score before and after Nissen fundoplication in reflux patients.

METHODS

Thirty-one patients (16 men, 15 women, mean age 46.5 y) were studied before and 3 months after Nissen fundoplication by stationary esophageal manometry, wireless Bravo pH system monitoring (48 hours), and water load test. A dyspepsia symptom questionnaire was also completed before and after surgery. Data were compared with those of 35 controls.

RESULTS

All patients had pH-monitoring positive for pathological acid exposure and/or related-reflux symptoms in the absence of motility disorders. Basal symptoms scores were higher in patients compared to controls and improved after surgery, except than postprandial fullness, early satiation, and bloating, that were significantly increased. At baseline, all patients ingested significantly lower water volumes than controls, with a tendency to early onset of fullness and nausea, respectively. After surgery, the water volumes were significantly lower than presurgery.

CONCLUSIONS

In patients with reflux-related symptoms, with or without esophagitis, the water load test is frequently abnormal, suggesting an altered gastric function. Nissen fundoplication is associated with a relatively higher incidence of bloating, epigastric pain and fullness. These preliminary data could explain the incomplete resolution of symptoms after surgery in some patients, and suggest the use of additional studies to explore the gastric function in presurgical evaluation.

British Society of Gastroenterology guidelines for oesophageal manometry and oesophageal reflux monitoring

These guidelines on oesophageal manometry and gastro-oesophageal reflux monitoring supersede those produced in 2006. Since 2006 there have been significant technological advances, in particular, the development of high resolution manometry (HRM) and oesophageal impedance monitoring. The guidelines were developed by a guideline development group of patients and representatives of all the relevant professional groups using the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool. A systematic literature search was performed and the GRADE (Grading of Recommendations Assessment, Development and Evaluation) tool was used to evaluate the quality of evidence and decide on the strength of the recommendations made. Key strong recommendations are made regarding the benefit of: (i) HRM over standard manometry in the investigation of dysphagia and, in particular, in characterising achalasia, (ii) adjunctive testing with larger volumes of water or solids during HRM, (iii) oesophageal manometry prior to antireflux surgery, (iv) pH/impedance monitoring in patients with reflux symptoms not responding to high dose proton pump inhibitors and (v) pH monitoring in all patients with reflux symptoms responsive to proton pump inhibitors in whom surgery is planned, but combined pH/impedance monitoring in those not responsive to proton pump inhibitors in whom surgery is planned. This work has been endorsed by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG) under the auspices of the oesophageal section of the BSG.

The role of oesophageal physiological testing in the assessment of noncardiac chest pain

Oesophageal physiology testing plays an important role in the diagnosis of noncardiac chest pain (NCCP) after cardiac, structural and mucosal abnormalities have been ruled out. Endoscopy can establish the presence of structural causes of chest pain such as cancer, oesophageal webs and diverticula. Even if macroscopically normal, eosinophilic oesophagitis is a common cause of chest pain and needs to be ruled out with an adequate biopsy regimen. In the remaining cases, diagnosis is focused on the identification of often subtle mechanisms that lead to NCCP. The most common oesophageal aetiologies for NCCP are gastro-oesophageal reflux disease (GORD), oesophageal dysmotility and functional chest pain. Ambulatory pH studies (with or without impedance or wireless measurements) can establish the presence of GORD, nonerosive reflux as well any association with symptoms of chest pain. High-resolution manometry, particularly with the inclusion of adjunctive testing, can rule out major motility disorders such as spasm, hypercontraction or achalasia. The EndoFLIP device can help define disorders with reduced distensibility, not easily appreciated with endoscopy or manometry. When all tests remain negative, a diagnosis of oesophageal hypersensitivity is normally made and therapy is shifted from targeting a disease to treating symptoms and patient affect.

Interference with daily activities and major adverse events during esophageal pH monitoring with bravo wireless capsule versus conventional intranasal catheter: a systematic review of randomized controlled trials

For three decades, ambulatory 24-hour intranasal pH monitoring has been the established gold standard for detecting acid reflux in patients with refractory gastroesophageal reflux disease. However, device-associated adverse events and unpleasant experiences, reported by patients during pH monitoring have led to the invention of more convenient pH monitors such as Bravo wireless capsule. To compare the interference with daily activities and major adverse events during pH monitoring with Bravo wireless capsule (Bravo) versus conventional intranasal catheter (catheter), PubMed, Cochrane Library, Clinical Trials.gov, and Google Scholar were searched up to March 20, 2015. Only randomized controlled trials in adult patients that compared the interference with routine daily activities and adverse events between Bravo and catheter pH monitors were included. After screening 574 articles, three unique studies with 167 patients met our inclusion criteria. The average age of patients enrolled in these studies was 51 years. Interference with normal daily activities was more in the catheter than Bravo group: 75 ± 5 versus 92 ± 2, P < 0.001 (Andrews et al, findings were reported as100 mm, mean visual analogue scale (VAS) ± standard error of the mean, 100 = completely normal); Wong et al. (mean ± standard error of the mean): 1.3 ± 0.2 versus 0.32 ± 0.1, P = 0.001 and Wenner et al. using 10 cm median VAS (Interquartile range),10 been the worst is 5.7 (2.3-8.0) compared to 0.7 (0.2-3.4), P < 0.0001, respectively. Overall adverse events were more in the catheter group than Bravo (39 ± 4 vs. 26 ± 4, P = 0.012 for Andrews et al. (100 been the worst) and 5.1 (2.0-6.6) vs. 2.1 (0.5-4.6), P < 0.001 for Wenner et al.). No overall adverse events recorded for Wong et al. Most patients in catheter group complained of nasal and throat symptoms. Significantly, runny nose in 24 out of 25 patients (96%) catheter versus 13 out of 25 (52%) Bravo, P = 0.001 and nose pain 15 out 25 (60%) versus 8 out of 25 patients (32%), P = 0.047, respectively for Wong et al. Andrews and Wenner et al also showed profound nasal discomforts in catheter group compared to Bravo (39 ± 3 vs. 10 ± 3, P < 0.001 and 6.5 (1.5-8.0) versus 0.2 (0.0-1.9), P < 0.0001, respectively. Throat symptoms reported in Wong et al. were mainly throat discomfort in catheter group 23 out of 25 patients (92%) versus Bravo 12 out of 25 (48%), P = 0.001 and throat pain catheter (12 out of 25 patients (48%) vs. Bravo 4 out of 25 (16%)), P = 0.032. This trend was also observed in Andrews et al. with profound throat discomfort in the catheter group 43 ± 4 compared to Bravo 19 ± 4, P < 0.001. Majority of the patients randomized to Bravo group reportedly perceived chest pain higher than those in catheter group; 9 out of 25 patients (36%) versus 2 out of 25 (8%), P = 0.037 in Wong et al. 29 ± 4 versus 14 ± 3, P = 0.001 for Andrews et al., 2.4 (0.3-5.9) versus 1.1 (0.3-2.9), P = 0.084 in Wenner et al. respectively (though not statistically significant). Bravo wireless capsule pH monitor interfered less with daily activities and adverse events were minimal compared to conventional intranasal catheter.

Nutcracker esophagus: demographic, clinical features, and esophageal tests in 115 patients

Nutcracker esophagus (NE) is a common esophageal motility disorder chacterized by high amplitude peristaltic contractions in the distal esophagus. While previous studies have examined selected aspects of this condition (e.g. pathogenesis and treatment), there is a paucity of data regarding demographic and clinical features in large cohorts of patients. The aim of this study was to describe demographics, clinical features, comorbidities, time to diagnosis, source of patient referral by specialty, and medication use in a large cohort of patients with NE. We retrospectively analyzed consecutive cases of NE diagnosed from 2008-2010. The electronic medical records of these patients were reviewed, and relevant information was extracted. We identified 115 patients with NE. The median age was 62 years (range 25-87 years), and 63% were female. The median time patients experienced symptoms prior to diagnosis was 24 months (0-480 months). Most patients presented to an internal medicine consultant (42%) or to a gastroenterologist (35%). Presenting symptoms were chest pain (31%) and dysphagia (21%). Gastroesophageal reflux disease (GERD) symptoms were common: heartburn occurred in 51% of patients, 77% had a prior history of GERD, and 78% were receiving acid suppressive medications. GERD was confirmed by testing in at least 35%. Psychiatric comorbidity occurred in 24% with half the patients receiving psychotropic medications. Irritable bowel syndrome (IBS) and fibromyalgia co-existed in 15% and 12% of patients, respectively. Surprisingly, opioids were prescribed to 26% of patients. No statistically significant correlation was found between esophageal motility parameters and symptoms. In this study, NE patients were more commonly middle-aged females experiencing a considerable amount of time between symptom onset and diagnosis. Many were initially evaluated by internists for dysphagia or chest pain and had a history of GERD. Medication prescribed prior to diagnoses frequently involved acid suppression, but narcotic and psychotropic prescriptions were also commonly used. Central sensitization syndromes (fibromyalgia and IBS), psychiatric comorbidity, and reflux commonly coexisted. Our study suggests that future investigations should address the role and interaction of GERD and psychiatric disorders in NE.

Clinical value of wireless pH-monitoring of gastro-esophageal reflux in children before and after proton pump inhibitors

Background

Wireless pH-monitoring is an accurate method for diagnosing adults with gastroesophageal reflux disease (GERD). The aim of this study was to evaluate the use of the Bravo capsule on children investigated for GERD in terms of safety, tolerability and feasibility before and after administration of proton pump inhibitors.

Methods

A Bravo capsule was inserted during upper endoscopy under general anaesthesia or deep sedation with propofol. 48-hour pH-metry was performed in 106 children (50 males, 56 females) at the median age of 11 years (range 17 months-18 years). On the second day of investigation, proton pump inhibitor (PPI) was given at a mean dose of 1.6 mg/kg (SD ±0.6 mg). The definition of GERD was set to a reflux index (RI) of ≥5% and DeMeester score (DMS) ≥14.7.

Results

Application of the capsule was successful in 103 of the 106 children (97.2%) and interpretable in 99 of these 103 (96.1%). 49 of the children with interpretable results (49.5%) had GERD according to RI, while 51 (56.7%) had GERD according to DMS. After PPI was given on day 2, RI decreased from a median of 4.9% (range 0.3-63.4%) to 2.2% (0–58.0%), while DMS decreased from a median of 17.6 (range 2.2-207.6) to 8.2 (0.3-178.6), respectively (p < 0.0001). No severe adverse events were reported.

Conclusion

Wireless pH-metry is a safe and tolerable method when investigating children for GERD. PPI given on the second day of assessment provides additional information on response to treatment suggesting that pH-metry preferably should be extended to 48 hours.

Diagnostic work-up of GERD

Gastroesophageal reflux disease (GERD) is frequently diagnosed by symptoms and good response to acid suppression with proton pump inhibitors. Further work up is required when the diagnosis of GERD is uncertain, for alarm symptoms, PPI-refractoriness, and often for extraesophageal presentations. Useful tools include endoscopy for mucosal assessment and reflux monitoring (pH or impedance-pH) to quantify reflux burden. Objective documentation of pathological reflux is mandatory prior to anti-reflux surgery. In some patients, symptoms that can be attributed to GERD may have other causes; in these patients, testing that excludes GERD helps direct the diagnostic and treatment efforts to other causes.

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.

[Updated guidelines 2012 for gastroesophageal reflux disease]

In 2010, a Korean guideline for the management of gastroesophageal reflux disease (GERD) was made by the Korean Society of Neurogastroenterology and Motility, in which the definition and diagnosis of GERD were not included. The aim of this guideline was to update the clinical approach to the diagnosis and management of GERD in adult patients. This guideline was developed by the adaptation process of the ADAPTE framework. Twelve guidelines were retrieved from initial queries through the Appraisal of Guidelines for Research & Evaluation II process. Twenty-seven statements were made as a draft and revised by modified Delphi method. Finally, 24 consensus statements for the definition (n=4), diagnosis (n=7) and management (n=13) of GERD were developed. Multidisciplinary experts participated in the development of the guideline, and the external review of the guideline was conducted at the finalization phase.

Esophagogastroduodenoscopy with conscious sedation does not interfere with catheter-based 24-h pH monitoring

AIM: To investigate the impact of esophagogastroduodenoscopy with conscious sedation on the subsequent 24-h catheter-based pH monitoring.

METHODS: Fifty patients with extra-esophageal symptoms of gastroesophageal reflux disease undergoing ambulatory dual-probe 24-h pH monitoring were enrolled from March 2010 to August 2011. All of the data were collected prospectively and analyzed retrospectively. Thirty-six patients (72%, group A) underwent pH monitoring shortly after esophagogastroduodenoscopy (EGD) with conscious sedation, and 14 patients (28%, group B) underwent pH monitoring without conscious sedation. The 24-h pH data from two time periods were analyzed: the first 4 h (Period I) and the remaining time of the study (Period II).

RESULTS: The mean age of the patients was 49.6 ± 12.5 years; 20 patients (40%) were men. The baseline data, including age, sex, body mass index, reflux esophagitis, the Reflux Symptom Index, and the Reflux Findings Score, were comparable between the two groups. The percentage of total time with a pH < 4 and the frequency of acid reflux during Period I were not significantly different between the two groups, as measured using both pharyngeal (0.03% ± 0.10% vs 0.07% ± 0.16%, P = 0.32; and 0.07 ± 0.23 episodes/h vs 0.18 ± 0.47 episodes/h, P = 0.33, respectively) and esophageal probes (0.96% ± 1.89% vs 0.42% ± 0.81%, P = 0.59; and 0.74 ± 1.51 episodes/h vs 0.63 ± 0.97 episodes/h, P = 0.49, respectively). The percentage of total time with a pH < 4 and the frequency of acid reflux were also not significantly different between Periods I and II in group A patients, as measured using both pharyngeal (0.03% ± 0.10% vs 0.23% ± 0.85%, P = 0.21; and 0.07 ± 0.23 episodes/h vs 0.29 ± 0.98 episodes/h, P = 0.22, respectively) and esophageal probes (0.96% ± 1.89% vs 1.11% ± 2.57%, P = 0.55; and 0.74 ± 1.51 episodes/h vs 0.81 ± 1.76 episodes/h, P = 0.55, respectively).

CONCLUSION: EGD with conscious sedation does not interfere with the results of subsequent 24-h pH monitoring in patients with extra-esophageal symptoms of gastroesophageal reflux disease.

GERD assessment including pH metry predicts a high response rate to PPI standard therapy

Background

Inadequate response to proton pump inhibitor (PPI) therapy in patients with gastroesophageal reflux disease (GERD) is reported in up to 40%. Patients with non erosive reflux disease (NERD) have lower response rates compared to patients with erosive reflux disease (ERD); pH metry contributes to GERD diagnosis and is critical for proper diagnosis of NERD.

Aim of the study was to assess the need for doubling esomeprazole standard dose (40 mg) for 4 weeks in PPI naive patients with typical reflux symptoms and diagnosis of GERD based on endoscopy and 48 hours, wireless pH metry.

Methods

All patients underwent upper GI endoscopy. Symptoms were recorded with a structured questionnaire (RDQ) and acid exposure was determined by 48 hours, wireless pH monitoring (BRAVO). In case of abnormal acid exposure, patients received a short term treatment with esomeprazole 40 mg q.d. for 4 weeks. If symptoms persisted, patients underwent a second pH metry on PPI and the dose was increased to 40 mg b.i.d.

Results

31 consecutive patients with typical reflux symptoms underwent 48 hours pH monitoring. 22 patients (71%) had abnormal acid exposure, 9 patients had normal pH metry (29%). Of the 9 patients with normal pH metry, 2 were found with erosive esophagitis and 7 without endoscopic abnormalities.

24 patients with documented GERD received esomeprazole treatment. 21 patients achieved complete symptom resolution with 40 mg q.d. after 4 weeks (88%). Only 2 patients required doubling the dose of esomeprazole for complete symptom resolution, 1 patient remained with symptoms.

Conclusions

Patients with typical reflux symptoms and abnormal acid exposure have a high response rate to standard dose esomeprazole regardless of whether they have ERD or NERD.

Comparative study of two modes of gastroesophageal reflux measuring: conventional esophageal pH monitoring and wireless pH monitoring

CONTEXT

Esophageal pH monitoring is considered to be the gold standard for the diagnosis of gastroesophageal acid reflux. However, this method is very troublesome and considerably limits the patient's routine activities. Wireless pH monitoring was developed to avoid these restrictions.

OBJECTIVE

To compare the first 24 hours of the conventional and wireless pH monitoring, positioned 3 cm above the lower esophageal sphincter, in relation to: the occurrence of relevant technical failures, the ability to detect reflux and the ability to correlate the clinical symptoms to reflux.

METHODS

Twenty-five patients referred for esophageal pH monitoring and with typical symptoms of gastroesophageal reflux disease were studied prospectively, underwent clinical interview, endoscopy, esophageal manometry and were submitted, with a simultaneous initial period, to 24-hour catheter pH monitoring and 48-hour wireless pH monitoring.

RESULTS

Early capsule detachment occurred in one (4%) case and there were no technical failures with the catheter pH monitoring (P = 0.463). Percentages of reflux time (total, upright and supine) were higher with the wireless pH monitoring (P < 0.05). Pathological gastroesophageal reflux occurred in 16 (64%) patients submitted to catheter and in 19 (76%) to the capsule (P = 0.355). The symptom index was positive in 12 (48%) patients with catheter pH monitoring and in 13 (52%) with wireless pH monitoring (P = 0.777).

CONCLUSIONS

1) No significant differences were reported between the two methods of pH monitoring (capsule vs catheter), in regard to relevant technical failures; 2) Wireless pH monitoring detected higher percentages of reflux time than the conventional pH-metry; 3) The two methods of pH monitoring were comparable in diagnosis of pathological gastroesophageal reflux and comparable in correlating the clinical symptoms with the gastroesophageal reflux.

Critical analysis of esophageal multichannel intraluminal impedance monitoring 20 years later

Multichannel intraluminal impedance (MII) for the evaluation of esophageal diseases was created in 1991 trying to solve previous limitations of esophageal function test. MII-pH is able to determine the physical characteristics of the refluxate (liquid, gas, or mixed) and nonacidic GER. MII-manometry can determine the presence of bolus and its relation with peristalsis. This paper makes a critical analysis of the clinical applications of MII 20 years after its creation. Literature review shows that MII made great contributions for the understanding of esophageal physiology; however, direct clinical applications are few. MII-pH was expected to identify patients with normal acid reflux and abnormal nonacidic reflux. These patients are rarely found off therapy, that is, nonacidic reflux parallels acid reflux. Furthermore, the significance of isolated nonacidic reflux is unclear. Contradictory MII-manometry and conventional manometry findings lack better understanding and clinical implication as well as the real significance of bolus transit.

Traditional vs wireless intragastric pH monitoring: are the two techniques comparable?

BACKGROUND

Few data are available comparing intragastric pH measured with the traditional catheter-based and the more recent wireless system (Bravo), and also comparing intraesophageal and intragastric pH during reflux events. Aims of our study were to elucidate these points.

METHODS

Eleven subjects with functional dyspepsia underwent placement of a Bravo capsule 9 cm below the squamo-columnar junction (SCJ) and of a dual-electrode catheter, so that the distal electrode was located 9 cm below and the proximal one 6 cm above the SCJ.

KEY RESULTS

The wireless system showed lower intragastric pH than the traditional catheter in the postprandial period (median 2.2 wireless vs 2.7 catheter, P < 0.05) but not in the whole 24 h. Moreover, during the 24 h, minimum intraesophageal pH during reflux events was lower than the simultaneous pH in the gastric body recorded using the catheter (2.2 vs 2.4, P < 0.01) and in the postprandial period lower than the one recorded using both techniques (2.3 vs 2.8 wireless and 3.2 catheter, P < 0.001).

CONCLUSIONS & INFERENCES

(i) after meals, in the 1st 2 h postprandial pH in the gastric body is significantly lower when measured with the wireless capsule than with the traditional catheter, presumably because of less buffering by food in proximity of the mucosa, (ii) during reflux events intraesophageal pH is lower than pH in the gastric body, in accordance with the notion of greater intragastric acidity in the subcardial region.

Utilization of wireless pH monitoring technologies: a summary of the proceedings from the esophageal diagnostic working group

Gastroesophageal reflux disease (GERD) can be difficult to diagnose - symptoms alone are often not enough, and thus, objective testing is often required. GERD is a manifestation of pathologic levels of reflux into the esophagus of acidic, nonacidic, and/or bilious gastric content. However, in our current evidence-based knowledge approach, we only have reasonable outcome data in regards to acid reflux, as this particular type of refluxate predictably causes symptoms and mucosal damage, which improves with medical or surgical therapy. While there are data suggesting that nonacid reflux may be responsible for ongoing symptoms despite acid suppression in some patients, outcome data about this issue are limited. Therefore, this working group believes that it is essential to confirm the presence of acid reflux in patients with 'refractory' GERD symptoms or extraesophageal symptoms thought to be caused by gastroesophageal reflux before an escalation of antireflux therapy is considered. If patients do not have pathologic acid reflux off antisecretory therapy, they are unlikely to have clinically significant nonacid or bile reflux. Patients who do not have pathologic acid gastroesophageal reflux parameters on ambulatory pH monitoring then: (i) could attempt to discontinue antisecretory medications like proton pump inhibitors and H2-receptor antagonists (which are expensive and which carry risks - i.e. C. diff, etc.); (ii) may undergo further evaluation for other causes of their esophageal symptoms (e.g. functional heartburn or chest pain, eosinophilic esophagitis, gastroparesis, achalasia, other esophageal motor disorders); and (iii) can be referred to an ear, nose, and throat/pulmonary/allergy physician for assessment of non-GERD causes of their extraesophageal symptoms.

Unsedated peroral wireless pH capsule placement vs. standard pH testing: a randomized study and cost analysis

BACKGROUND

Wireless capsule pH-metry (WC) is better tolerated than standard nasal pH catheter (SC), but endoscopic placement is expensive.

AIMS

to confirm that non-endoscopic peroral manometric placement of WC is as effective and better tolerated than SC and to perform a cost analysis of the available esophageal pH-metry methods.

METHODS

Randomized trial at 2 centers. Patients referred for esophageal pH testing were randomly assigned to WC with unsedated peroral placement or SC after esophageal manometry (ESM). Primary outcome was overall discomfort with pH-metry. Costs of 3 different pH-metry strategies were analyzed: 1) ESM + SC, 2) ESM + WC and 3) endoscopically placed WC (EGD + WC) using publicly funded health care system perspective.

RESULTS

86 patients (mean age 51 ± 2 years, 71% female) were enrolled. Overall discomfort score was less in WC than in SC patients (26 ± 4 mm vs 39 ± 4 mm VAS, respectively, p = 0.012) but there were no significant group differences in throat, chest, or overall discomfort during placement. Overall failure rate was 7% in the SC group vs 12% in the WC group (p = 0.71). Per patient costs ($Canadian) were $1475 for EGD + WC, $1014 for ESM + WC, and $906 for ESM + SC. Decreasing the failure rate of ESM + WC from 12% to 5% decreased the cost of ESM + WC to $991. The ESM + SC and ESM + WC strategies became equivalent when the cost of the WC device was dropped from $292 to $193.

CONCLUSIONS

Unsedated peroral WC insertion is better tolerated than SC pH-metry both overall and during placement. Although WC is more costly, the extra expense is partially offset when the higher patient and caregiver time costs of SC are considered.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier NCT01364610.

Bravo 48-hour Wireless pH Monitoring in Patients With Non-cardiac Chest Pain. Objective Gastroesophageal Reflux Disease Parameters Predict the Responses to Proton Pump Inhibitors

Background/Aims

In patients with non-cardiac chest pain (NCCP), gastroesophageal reflux disease (GERD) is the commonest cause and ambulatory pH is of great value in identifying these patients. However, parameters in the context of predicting therapeutic response are still unknown. By extending the monitoring period, we could better evaluate the best evidence for GERD association. Our aims were (1) to compare the outcomes of 48-hour pH monitoring to 24-hour and (2) to determine whether objective parameters could predict the treatment success in patients with NCCP using Bravo pH system.

Methods

Pathological esophageal acid reflux (PEAR) and positive symptom index (SI) were calculated after 24-hour and compared to the 48-hour study. Evidence suggestive of GERD diagnosis was considered if PEAR and/or SI (+) were present on each different day. After pH study, all patients received proton pump inhibitor twice a day for 4 weeks. Treatment success was determined at the end of therapy.

Results

Thirty-two patients with NCCP participated. GERD was identified in 20 (62.5%) patients; 17 (53.1%) had PEAR, 3 (9.4%) SI (+) and 7 (22%) both. Twelve (41%) patients exhibited PEAR values on day 1, while 17 after 2 days; a 12.1% gain. SI (+) was found in 6 patients (18.8%) on day 1 and in 4 more on day 2, a gain of 12.5%. Significantly higher proportion of patients with GERD indicators showed improvement compared to those without (90% vs 16.7%, P < 0.005).

Conclusions

In patients with NCCP, 48-hour pH measurement identified GERD as the cause of NCCP with an increased yield by almost 12% compared to 12 hours. Objective GERD parameters could predict response to antireflux therapy.

Esophageal spasm: demographic, clinical, radiographic, and manometric features in 108 patients

Diffuse esophageal spasm (DES) remains insufficiently understood. Here we aimed to summarize the demographic, clinical, radiographic, and manometric features in a large cohort of patients with DES. We identified all consecutive patients diagnosed with DES from 2000 to 2006 at Mayo Clinic Florida. The computerized records of these patients were reviewed to extract relevant information. We performed 2654 esophageal motilities during that period. There were 108 patients with esophageal spasm, and 55% were female. Median age was 71 years. The most common leading symptom was dysphagia in 55, followed by chest pain in 31. Weight loss occurred in 28 patients. The median of time from onset of symptoms to diagnosis was 48 months (range 0-480), with a median of time from the first medical consultation to diagnosis of 8 months (range 0-300). The most frequent comorbidities were hypertension and psychiatric problems. At presentation, 81 patients were taking acid-reducing medications, and 49 patients were taking psychotropic drugs. An abnormal esophagogram was noted in 46 of 76 patients with this test available, but most radiographic findings were nonspecific with the typical 'corkscrew' appearance seen in only three patients. Gastroesophageal reflux disease (GERD) was diagnosed by pH testing or endoscopy in 41 patients. We did not find any difference between the rate of simultaneous contractions or esophageal amplitude between patients with a leading symptom of dysphagia and those with chest pain. DES is an uncommon motility disorder that often goes unrecognized for years. Physicians should be aware of the clinical heterogeneity of DES and consider motility testing early in the course of unexplained esophageal symptoms. Given the high prevalence of GERD in DES, the role of GERD and the impact of acid-reducing therapy in DES deserve further study.

Wireless ambulatory pH studies: manometric or endoscopic guidance?

Wireless pH studies are widely used to assess the presence and severity of gastroesophageal reflux disease. We hypothesized that sedation or air insufflation during a preceding endoscopy may systematically alter results. A retrospective review of ambulatory pH studies completed between January 2008 and April 2010 was performed. The pH capsule was placed 6 cm above the endoscopically determined location of the squamocolumnar junction or 5 cm above the manometrically localized upper border of the lower esophageal sphincter (LES). A total of 356 patients (65% women) underwent pH studies using the BRAVO system (GIVEN Imaging, Yoqneam, Israel). In 186 patients (E-P), the capsule was placed during endoscopy. In 170 patients (M-P), capsule placement was based on manometric determination of LES boundaries using pharyngeal anesthesia only. Endoscopic placement was successful in all cases, whereas two patients could not tolerate capsule insertion with topical anesthesia only. The mean recording time did not differ between the two groups (E-P: 2468 ± 38 min; M-P: 2415 ± 40 min). The number of patients with abnormal findings on day 1 but normal results for day 2 was similar with 15% for E-P compared with 11% for M-P. However, there was a significant difference in total acid exposure times between days 1 and 2 for endoscopically (day 1: 7.3 ± 1.2; day 2: 4.8 ± 0.5; P < 0.01), but not manometrically based placement (day 1: 7.7 ± 0.7; day 2: 7.2 ± 0.6). There was no difference in the number of symptoms between days or groups (E-P day 1:13.4 ± 1.3; E-P day 2: 16.0 ± 1.6; M-P day 1: 14.1 ± 2.1; M-P day 2: 15.7 ± 2.0). Similarly, the symptom sensitivity index did not differ significantly between days and groups (E-P: day 1: 4.1 ± 0.5; day 2: 5.9 ± 0.8; M-P: day 5.3 ± 0.8; day 2: 5.7 ± 0.8). The majority of patients tolerate insertion of a wireless pH monitoring capsule without sedation. Unsedated placement did not negatively affect total recording times. Although endoscopy resulted in higher acid exposure on day one it did not significantly increase the overall fraction of abnormal tests. If confirmed in prospective studies, the more consistent findings and a potential to lower cost favor manometrically guided capsule placement.

Esophageal pH monitoring with the BRAVO capsule: experience in a single tertiary medical center

AIM

The aim of the present study was to report the global experience with placement, complication rate, and recording of esophageal pH using the BRAVO capsule at our institution.

PATIENTS AND METHODS

We recorded the rate of any technical problems and complications during placement in all of the patients (ages 4-22 years) who received this device during a 2-year period. All of the patients undergoing esophagogastroduodenoscopy with the placement of BRAVO pH capsule were included in this analysis. We also examined the pH data recorded on days 1 and 2 for significant day-to-day variability during 2 days of pH monitoring.

RESULTS

Two hundred eighty-nine BRAVO pH probes were placed from January 1, 2006 to December 31, 2008. At least 1 day of data was obtained in 278 patients (96.2%). Two days of data were obtained in 274 patients (94.8%). Of all of the reported complications, 1% occurred before deployment of the capsule, 4% occurred during deployment of the capsule, and 9% occurred after successful deployment of the capsule. One patient experienced a superficial esophageal tear that was associated with failure of the capsule to release from the delivery system. No patient requested removal of the capsule and all of the capsules detached within 14 days. In 9.12% of our patients, reflux index was normal on day 1 and abnormal on day 2. There was no statistically significant difference between reflux index recorded on day 1 versus day 2 (P = 0.686).

CONCLUSIONS

The BRAVO pH capsule is easy to place, safe, and well tolerated by children. Performing a 48-hour study detected abnormal reflux in an additional 9% of our patients.

Differential diagnosis in allergy

The otolaryngic allergist must be able to distinguish between common nonallergic diagnoses that present very similarly to allergic conditions. This article describes a few of the vast myriad of conditions that must be ruled out before a diagnosis of allergy may be made. After reading this article clinicians will be able to identify various conditions, which will enhance their ability to appropriately make correct decisions for prompt and efficient management of their patients with allergic or nonallergic diseases of the head and neck.

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

AIM: To evaluate the technical failures of the Bravo pH test in a population with nonerosive gastroesophageal reflux disease.

METHODS: Over the course of a year, we prospectively studied a population of 66 nonerosive reflux disease patients who received a Bravo pH test. The number and frequency of all technical failures were documented, quantified and analyzed.

RESULTS: A total of 66 patients, with a mean age of 41.7 years, were studied. Technical failures occurred in 15.15% of the sample. The most frequent failures were due to poor data reception (4.5%), early dislodgement (4.5%) and capsule removal (6.1%).

CONCLUSION: The Bravo capsule pH test involves a low but non-negligible rate of technical problems, a fact that must always be considered by physicians.

Efficacy of three different dosages of esomeprazole in the long-term management of reflux disease: a prospective, randomized study, using the wireless Bravo pH system

OBJECTIVES

Gastroesophageal reflux disease (GERD) is a chronic condition that usually requires long-term maintenance therapy with proton-pump inhibitors (PPIs). In clinical practice, patients receive PPIs at the lowest dose to control symptoms. However, it is not known whether this approach adequately controls acidic esophageal reflux. We sought to investigate the efficacy of three different dosages of esomeprazole in patients receiving maintenance therapy for GERD, using the Bravo pH system.

METHODS

Patients with a previous history of erosive esophagitis A or B (LA classification) that was healed at the time of enrollment or endoscopy-negative reflux disease (ENRD), documented with an abnormal pH study, were randomized to receive maintenance therapy with esomeprazole 40 mg twice daily (group A), once daily (group B), or every other day (group C). Intraesophageal pH was monitored for two consecutive days using the Bravo wireless system, 30 days after randomization. The parameters subjected to analysis were percent of total time pH<4 and the De Meester score.

RESULTS

The pH results from 73 patients (group A=24, group B=24, group C=25 patients) were subjected to final analysis. On the first day of the study, the mean (+/-s.d.) percent of total time pH <4 and the De Meester score were group A: 0.9(1.2) and 4.1(4.0); group B: 1.5(1.6) and 7.0(6.9); group C: 1.3(1.0) and 6.0(3.3), respectively (P=0.262 and 0.134, respectively). On the second day of the study, the corresponding values were group A: 0.7(1.0) and 3.9(5.9); group B: 1.5(1.8) and 6.4(6.6); group C: 7.0(4.4) and 29.4(19.4), respectively. The difference was statistically significant (P<0.0001 and <0.0001, respectively). Further analysis showed that patients not receiving PPI had a significantly higher mean percent of total time pH<4 and De Meester score as compared with patients on PPI once or twice daily (P<0.001 and <0.001 respectively).

CONCLUSIONS

The administration of esomeprazole 40 mg every other day does not control acidic esophageal reflux on the day off PPI. Esomeprazole 40 mg once daily effectively controls reflux of acid in patients with history of mild esophagitis or ENRD, whereas doubling the dose does not seem to confer any further advantage.

To Bravo or not? A comparison of wireless esophageal pH monitoring and conventional pH catheter to evaluate non-erosive gastroesophageal reflux disease in a multiracial Asian cohort

OBJECTIVE

Non-erosive reflux disease (NERD) constitutes the majority of patients with gastroesophageal reflux disease (GERD). Esophageal pH monitoring is useful in distinguishing patients with NERD from functional heartburn. The gastroenterologist often faces the dilemma of choosing the most appropriate investigative modality. The wireless Bravo capsule allows prolonged 48 hour monitoring with improved patient tolerance, but concerns regarding its reduced sensitivity compared to conventional pH catheter have been raised. We compared the prevalence of high esophageal acid exposure and positive symptom correlation profiles (using the symptom index [SI] and symptom association probability [SAP]) in patients who underwent Bravo compared to patients who underwent conventional pH catheter, and evaluated the efficacy of Bravo monitoring in a multiracial Asian cohort.

METHODS

Retrospective analysis of all pH studies performed between January 2004 and February 2009 for patients with persistent reflux symptoms and a normal gastroscopy.

RESULTS

66 (27 Male, 42.4 +/- 13.4 years) and 55 (24 Male, 47.1 +/- 13.3 years) patients underwent wireless and pH catheter evaluation respectively. "True NERD" (abnormal acid exposure) was diagnosed in 26 (39.4%) and 20 (36.4%) patients (pNS) while "acid-sensitive esophagus" (SI > or = 50% and/or SAP > or = 95%) occurred in 14 (21.2%) and 12 (21.8%) patients (pNS) using the wireless and pH catheter respectively. Extended recording time with Bravo led to an incremental diagnostic yield of 30%.

CONCLUSION

The wireless capsule was well tolerated. The diagnostic yield was similar using both modalities. With the increasing availability of impedance-pH technology, it is uncertain if devices that detect only acid-reflux events will be surpassed.

Comparison of esophageal placement of Bravo capsule system under direct endoscopic guidance with conventional placement method

Background:

Conventional placement of a wireless esophageal pH monitoring device in the esophagus requires initial endoscopy to determine the distance to the gastroesophageal junction. Blind placement of the capsule by the Bravo delivery system is followed by repeat endoscopy to confirm placement. Alternatively, the capsule can be placed under direct vision during endoscopy. Currently there are no published data comparing the efficiency of one method over the other. The objective of this study was to compare the method of Bravo wireless pH device placement under direct visualization with the conventional method.

Methods:

A retrospective study involving 58 patients (29 patients with indirect and 29 patients with direct visualization) who had Bravo capsule placement. The physician endoscopy procedure notes, nurse’s notes, postprocedure notes, recovery notes, and pH monitoring results were reviewed. The safety of the procedures, length of the procedures, and patient tolerability were evaluated.

Results:

None of the 58 patients had early detachment of the device and had no immediate procedure-related complications. The overall incidence of complications in both the groups was similar. No failures due to the technique were noted in either group. Average amount of time taken for the procedure was similar in both groups.

Conclusion:

The technique of placing a Bravo pH device under direct visualization is as safe and effective as the conventional method. In addition, there is an added advantage of avoiding a second endoscopic intubation in the direct visualization technique.

Subcardial 24-h wireless pH monitoring in gastroesophageal reflux disease patients with and without hiatal hernia compared with healthy subjects

OBJECTIVES

After meals, highly acidic gastric juice is present in the subcardial region, the so-called acid pocket. Patients with gastroesophageal reflux disease (GERD) have a higher frequency of acidic reflux. Our aim was to investigate the possible differences in subcardial pH in GERD over 24 h and the role of hiatal hernia (HH), using a wireless capsule.

METHODS

A total of 14 healthy volunteers (4 men, 24-60 years), 10 GERD patients without HH (4 men, 25-68 years), and 11 GERD patients with HH >or=3 cm (2 men, 46-74 years) underwent 24-h wireless pH monitoring 2 cm below the squamocolumnar junction. All patients had increased 24-h acid reflux. A standardized lunch was given to all study subjects.

RESULTS

No capsule detached during the 24-h recording. Median 24-h pH was similar in healthy subjects, and in patients without and with HH, median: 1.4 (interquartile range: 1.2 -1.9), 1.5 (1.3 -1.7), and 1.4 (1.3 -1.7), respectively. Similar results were seen in the supine period. Median pH after the standardized meal was often highly acidic, 2.7 (1.5 - 3.2), 1.9 (1.6 - 2.3), and 2.5 (1.6 - 3.2), respectively. The first minute with a median pH <2 occurred 14 min (4 - 49), 14 min (6 - 25), and 20 min (4 - 43), respectively, P=NS, after the end of the meal. Similar data were observed on pooling all meals together.

CONCLUSIONS

Subcardial pH is confirmed to be highly acidic early after meals, but it is similar over 24 h in healthy subjects and GERD patients independent of the presence of HH.

Patient acceptance and clinical impact of Bravo monitoring in patients with previous failed catheter-based studies

BACKGROUND

Standard pH monitoring is performed over 24 h with a naso-oesophageal catheter (C-pH). Limitations include naso-pharyngeal discomfort, nausea and social embarrassment resulting in reduced reflux-provoking activities. Recently a catheter-free pH-monitoring technique has become available. The tolerability and diagnostic yield of this system in patients who failed standard monitoring remain unknown.

AIM

To examine the tolerability and diagnostic outcome of catheter-free pH-monitoring technique in patients who failed standard monitoring.

METHODS

Patients referred for C-pH and catheter-free pH monitoring completed a tolerability questionnaire. Acid exposure in the distal oesophagus and symptom index (SI) were reviewed.

RESULTS

Over 4 years, 883/1751 (50%) of patients with typical reflux symptoms referred for C-pH were diagnosed with gastro-oesophageal reflux disease (GERD) based on a pathological percentage time acid exposure (%time pH <4);134 (8%) patients failed C-pH and, of these, 129 successfully completed 2-day catheter-free pH monitoring. Ninety-eight (76%) of these patients had a pathological percentage pH <4 on either day compared with 49/102 (49%) of contemporaneous C-pH patients (P < 0.01). There was no difference in SI for heartburn (35% vs. 42%; P = 0.49). The questionnaire demonstrated a preference for catheter-free pH monitoring (96%) with less restriction in activities of daily living, naso-pharyngeal discomfort, dysphagia and chest pain.

CONCLUSIONS

Tolerance and satisfaction with catheter-free pH monitoring are high in patients who had previously failed C-pH; catheter-free pH monitoring assists the definitive diagnosis of GERD in this group.

Obesity is associated with increased 48-h esophageal acid exposure in patients with symptomatic gastroesophageal reflux

OBJECTIVES

Obesity has been associated with gastroesophageal reflux disease (GERD) but the relationship between body mass index (BMI) and esophageal acid exposure remains poorly understood. We hypothesized that overweight (OW) and obese (OB) patients with GER symptoms would have a higher degree of esophageal acid exposure than with normal weight (NW) patients.

METHODS

157 patients separated in groups according to BMI were studied for 48h while off antisecretory medications using ambulatory wireless capsule pH-metry. The pH capsule was appropriately positioned and esophageal pH data were collected. Appropriate univariate and multivariate statistical methods were used.

RESULTS

Groups did not differ in age, but more women were in the NW group. OB patients had a fivefold increase in odds for abnormal total acid exposure compared with NW (OR=5.01; 95% CI 2.94, 12.95). Total acid exposure time (AET) was elevated in OB (8.7%+/-5.1%) compared with NW (5.3%+/-5.2%; P<0.05). AET was highest during awake, upright periods. The DeMeester score was higher in OB (31.7+/-19.2) and OW (26.0+/-16.8) groups compared with the NW (19.8+/-17.6) group (P<0.001). AET increased from day 1 to day 2 in the OB group only.

CONCLUSIONS

This is the first study to report a positive relationship between BMI and esophageal acid exposure time using prolonged, continuous wireless esophageal pH-metry. Abnormal AET was more frequent in OB patients. Variability in AET increased from day 1 to day 2 in the OB group, supporting the use of more prolonged pH studies in subsets of patients.

A novel placement method of the Bravo wireless pH monitoring capsule for measuring intragastric pH

PURPOSE

The delivery system of the Bravo capsule was designed for placement on the esophagus. We evaluated the feasibility of our novel placement method of the Bravo capsule using a clip to monitor intragastric pH and to compare the accuracy of the Bravo wireless system to the traditionally used Slimline catheter-Mark III Digitrapper pH monitoring system.

METHODS

The Bravo capsule was placed by clip or conventional delivery system using suction on the gastric wall in 20 fasted subjects. A separate group of ten healthy volunteers underwent simultaneous intragastric pH monitoring for comparison of the two systems with meals.

RESULTS

Early dislodgment rate of the capsules was lower when placed using clipping (20%) than using conventional delivery system (70%) within 48 h after placement. We observed prominent movement of one catheter in the stomach during the study. Post-test calibration drifts of the catheters at pH 7.01 were significantly greater than those of the Bravo capsules (P = 0.02).

CONCLUSION

Our novel clipping method of the Bravo pH capsule placement provided accurate monitoring of intragastric pH with merits of tolerability, acid stability, and fixing position.

[Outpatient monitoring of oesophageal pH with a catheter-free pH-meter (Bravo System). A Study of tolerance, safety and efficacy]

BACKGROUND AND OBJECTIVE

A new catheter-free outpatient oesophageal pH-meter system (Bravo) has recently been developed. The objective of this study is to test the tolerance, safety and efficacy of the system in the measurement of gastric-oesophageal reflux by comparing it with a conventional pH system.

PATIENTS AND METHOD

The study was performed on a control group consisting of 10 healthy volunteers (group 1) and in a group of 40 patients with symptoms of gastric-oesophageal reflux disease (groups 2 and 3). An upper digestive system endoscopy, oesophageal manometry and oesophageal pH measurements with a conventional system and/or with the Bravo catheter-free system, was performed on all patients. All patients who had both tests done (groups 1 and 2) filled in a questionnaire on any physical problems and changes in their daily activity.

RESULTS

The test tolerance was higher with the Bravo system in the 9 parameters studied. In the group of healthy volunteers (group 1), the median (range) of the total percentage of pH < 4 was 1.1% (0.5-3.1) with the conventional pH and 1.7% (0-3.4) with the Bravo. When comparing the patients with symptoms of gastric-oesophageal reflux disease (group 2) with those who had only one type of pH measurement made, the acid reflux was significantly higher in patients with Barrett's oesophagus than in the rest of the groups, with conventional pH as well as with the Bravo. If we analyse the patient group with disease due to gastric-oesophageal reflux with those on whom both techniques were used (group 3), 7 of the 10 patients had a pathological reflux that only showed up on measuring pH with the Bravo system.

CONCLUSIONS

Catheter-free pH measurements (Bravo) is better tolerated and with better satisfaction for the healthy volunteers and patients than with conventional PH, even, on occasions being more efficient for studying acid reflux due to the lower incidence of negative results.

New esophageal function testing (impedance, Bravo pH monitoring, and high-resolution manometry): clinical relevance

Esophageal testing aims to quantify gastroesophageal reflux or characterize esophageal motility. Reflux monitoring traditionally has been based on the detection of acidic reflux by a transnasal catheter that measures esophageal pH. Recently there have been two major developments in this field: the wireless Bravo pH capsule (Medtronic, Inc., Minneapolis, MN), which allows catheter-free monitoring, and impedance-pH measurement, a catheter-based technique that enables detection of acidic and nonacidic reflux. The assessment of esophageal motility has relied on conventional manometry for many years. Two new procedures also recently became available to assess esophageal motility: high-resolution manometry, which uses many closely spaced pressure sensors and provides spatiotemporal plots of esophageal pressure changes, and impedance manometry, a test that directly measures bolus transit and provides conventional manometric data. The advantages, disadvantages, and clinical importance of these new esophageal tests are discussed in this review.

Use and utility of the Bravo pH capsule

The single technological advancement that Bravo pH monitoring offers over conventional pH monitoring is the elimination of the transnasal catheter. This was not a trivial advance in terms of technologic achievement. Development of a delivery system that could temporarily place a wireless capsule on the esophageal mucosa was extremely difficult to envision given the fact that the esophageal body is not conducive to retaining a foreign body. Thus, the delivery system and the ability to attach the pH capsule to the wall are what make the Bravo system unique. This approach has the potential to improve tolerance and obtain pH studies for durations greater than 24 hours; however, it still lacks the ability to measure nonacid reflux and also the ability to distinguish swallow events from true reflux. This review will highlight the advantages of the Bravo system and how it should be used.

Endoscopic pH monitoring for patients with suspected or refractory gastroesophageal reflux disease

BACKGROUND

Wireless pH studies can offer prolonged pH monitoring, which may potentially facilitate the diagnosis and management of patients with gastroesophageal reflux disease (GERD). The aim of the present study was to evaluate the detection rate of abnormal esophageal acid exposure using prolonged pH monitoring in patients with suspected or refractory GERD symptoms.

METHODS

Patients undergoing prolonged ambulatory pH studies for the evaluation of GERD-related symptoms were assessed. Patients with a known diagnosis of GERD were tested on medical therapy, while patients with suspected GERD were tested off therapy. The wireless pH capsules were placed during upper endoscopy 6 cm above the squamocolumnar junction.

RESULTS

One hundred ninety-one patients underwent a total of 198 pH studies. Fifty ambulatory pH studies (25%) were excluded from the analysis: 27 patients (14%) had insufficient data capture (less than 18 h on at least one day of monitoring), 15 patients had premature capsule release (7%), seven were repeat studies (3.5%) and one had intolerable pain requiring capsule removal (0.5%). There were 115 patients undergoing pH studies who were off medication, and 33 patients were on therapy. For the two groups of patients, results were as follows: 32 (28%) and 22 (67%) patients with normal studies on both days; 58 (50%) and five (15%) patients with abnormal studies on both days; 18 (16%) and three (9%) patients with abnormal studies on day 1 only; and seven (6%) and three (9%) patients with abnormal studies on day 2 only, respectively.

CONCLUSIONS

Prolonged 48 h pH monitoring can detect more abnormal esophageal acid exposure but is associated with a significant rate of incomplete studies.

The Bravo pH capsule system

Limitations of existing pH recording methodology have been the impetus for the emergence of new technologies focused on improving ambulatory pH monitoring. The Bravo pH capsule system (Bravo, Medtronic, Shoreview, MN) is one of the recent advances that utilize a wireless system to improve patient compliance and extend the period of monitoring. These changes could potentially improve diagnostic accuracy along with patient acceptance. Given this fact, the following review will evaluate the potential benefits that wireless pH monitoring may have over conventional catheter based pH monitoring based on the available data. In addition, we will also focus on the technical aspects related to its safety, tolerability and diagnostic accuracy.

New technologies to evaluate esophageal function

This review provides an overview of the recent advances made in diagnostic technologies of esophageal functional disorders. There is discussion of technologies that evaluate esophageal motor function with special attention to high-resolution manometry and esophageal manometry combined with intraluminal impedance testing. Technologies to evaluate gastroesophageal reflux disease are presented with focus on 24-h ambulatory pH monitoring with intraluminal impedance testing and 48-h ambulatory catheter-free pH monitoring. These new technologies have advanced the study and treatment of esophageal disorders in that they allow for more accurate diagnosis of known esophageal disorders and have introduced previously unexplored disorders, such as achalasia with shortening of the esophagus and nonacid reflux.

New method for long-term monitoring of intragastric pH

AIM: Consecutive monitoring of intragastric pH using the Bravo^® capsule.

METHODS: We put threads through a Bravo^® capsule and then affixed it to the gastric wall by endoscopic hemoclipping in seven subjects. Study data were uploaded to a computer via Datalink every 48 h. In this way, repeated monitoring of intragastric pH was undertaken.

RESULTS: All subjects were able to monitor gastric pH over a 1-wk period, and five for > 2 wk. No complications were encountered during the monitoring. After pH monitoring, we safely retrieved the capsule endoscopically.

CONCLUSION: Clipping a Bravo^® capsule onto the gastric wall enabled long-term intragastric pH monitoring. This is a methodological report of pH monitoring over a period of > 2 wk.

Water load test before and after PPI therapy in patients with gastro-oesophageal reflux disease

BACKGROUND

Patients with gastro-oesophageal reflux disease may complain of epigastric pain, bloating, early satiety, epigastric fullness, epigastric burning, nausea and vomiting.

AIMS

To evaluate the symptoms in response to gastric distension and its relationship to a therapeutic course in patients with gastro-oesophageal reflux disease using the water load test, compared to healthy controls.

METHODS

Thirty gastro-oesophageal reflux disease patients with grade A oesophagitis (studied before and after 4 weeks of therapy with esomeprazole, 40 mg per day) and 15 patients with reflux-related symptoms demonstrated at wireless pH monitoring (non-erosive reflux disease) were compared to 30 healthy volunteers.

RESULTS

Patients with grade A oesophagitis and with reflux-related symptoms ingested significantly lower water volumes than did controls, before onset of fullness, without statistically significant difference between erosive or non-erosive gastro-oesophageal reflux disease; this variable improved in patients after treatment. Nausea scores were higher basally in patients, pre- and post-therapy, and improved after therapy. Thirty-minute fullness and bloating scores improved after therapy in all gastro-oesophageal reflux disease patients compared to controls and pre-therapy. In all pre-treatment patients, a significant correlation was found only with epigastric fullness; after treatment, there was no significant relationship between the water load and the symptom scores.

CONCLUSIONS

In patients with reflux-related symptoms, with or without grade A oesophagitis, the water load test is frequently abnormal, suggesting an altered gastric function. This could explain the incomplete resolution of symptoms after treatment in some patients, and should lead to additional studies aimed at exploring gastric function in gastro-oesophageal reflux disease patients.

The impact of prolonged pH measurements on the diagnosis of gastroesophageal reflux disease: 4-day wireless pH studies

INTRODUCTION

Prolonged, 4-day (96 h) measurement by the wireless Bravo system provides an opportunity to assess the variance, diagnostic reproducibility, and yield of 24- and 48-h pH and symptom association studies.

METHOD

Retrospective analysis of 83 patients with suspected reflux symptoms undergoing wireless pH monitoring with the intention of 96-h measurement. Study periods were classified based on esophageal acid exposure, the DeMeester score (DMS), and the association of reflux events and symptoms (symptom index). The technical success of prolonged pH recording and diagnostic accuracy of 24-, 48-, and 72-h pH studies compared to the 96-h "gold standard" were assessed.

RESULTS

Prolonged Bravo pH studies were possible and well tolerated in routine clinical practice. Complete 96-h recordings were available for 34/83 (41%) patients. Variation in pH measurements reduced with increasing study duration (24-h 45%vs 48-h 27%, P<0.01), but no change in reflux severity over time was observed (ANOVA, P=ns). Abnormal acid exposure was found in 7 (19%) on every test day and 21 (58%) on at least one of four test days. A diagnosis consistent with the 96-h "gold standard" was present in 22 (63%), 29 (83%), and 32 (91%) patients for 24-, 48-, and 72-h test periods, respectively, with a significant improvement of diagnostic sensitivity with study duration (P<0.01). Similar findings were present for symptom association.

CONCLUSION

Increasing the duration of pH studies progressively improves measurement variance and the diagnostic reproducibility of reflux studies. Future studies must address the impact of prolonged pH studies on clinical management.

Accuracy and tolerability of the Bravo catheter-free pH capsule in patients between the ages of 4 and 18 years

OBJECTIVE

The aim of this study was to determine if the Bravo pH capsule is comparable to the nasally placed pH catheter in terms of pH-metry, safety, and tolerability in children.

METHODS

Ten patients each in the age ranges of 4 to 6 years, 7 to 10 years, and >10 years were tested simultaneously with the catheter and the capsule. Six each were tested with the catheter alone or the capsule alone. Subjects recorded adverse events and graded tolerance (in terms of activity, appetite, and satisfaction) on a scale of 1 to 5, with a score of 5 indicating that the device was well tolerated. A 24-hour reflux index and 24- and 48-hour reflux indices were generated from the catheter and capsule, respectively. Student t test, Mann-Whitney U test, and Fisher exact test were used to compare reflux index, tolerability, and adverse events between the catheter and capsule.

RESULTS

Sixty-six patients 4 to 16 years of age (mean, 9.4 years) were enrolled. There was no statistically significant difference between the mean reflux indices (RIs) obtained simultaneously with the catheter and capsule in all patients combined on day 1 (P = 0.0665). There was a significant difference between day 2 and days 1 and 2 combined with the capsule versus the catheter (P = 0.007 and P = 0.0107); however, a discordant result of normal RI on day 1 and pathological RI on day 2 was seen in only 1 patient. The capsule was better tolerated than the catheter in terms of appetite (P = 0.029), activity (P = 0.001), and satisfaction (P = 0.003). There were no significant complications.

CONCLUSIONS

The Bravo pH capsule was as accurate and safe and better tolerated than the conventional pH catheter in children 4 years of age and older.