Combined multichannel intraluminal impedance-pH monitoring to select patients with persistent gastro-oesophageal reflux for laparoscopic Nissen fundoplication

Endoscopic full-thickness plication for the treatment of gastroesophageal reflux disease using multiple Plicator implants: 12-month multicenter study results

BACKGROUND

The full-thickness Plicator (Ethicon Endosurgery, Sommerville, NJ, USA) was developed for endoscopic treatment of gastroesophageal reflux disease (GERD). The goal is to restructure the antireflux barrier by delivering transmural pledgeted sutures through the gastric cardia. To date, studies using this device have involved the placement of a single suture to create the plication. The purpose of this study was to evaluate the 12-month safety and efficacy of this procedure using multiple implants to restructure the gastroesophageal (GE) junction.

METHODS

A multicenter, prospective, open-label trial was conducted at four tertiary centers. Eligibility criteria included symptomatic GERD [GERD Health-Related Quality-of-Life (GERD-HRQL) questionnaire, off of medication], and pathologic reflux (abnormal 24-h pH) requiring daily proton pump inhibitor therapy. Patients with Barrett's epithelium, esophageal dysmotility, hiatal hernia > 3 cm, and esophagitis (grade III or greater) were excluded. All patients underwent endoscopic full-thickness plication with linear placement of at least two transmural pledgeted sutures in the anterior gastric cardia.

RESULTS

Forty-one patients were treated. Twelve months post treatment, 74% of patients demonstrated improvement in GERD-HRQL scores by > or = 50%, with mean decrease of 17.6 points compared with baseline (7.8 vs. 25.4, p < 0.001). Using an intention-to-treat model, 63% of patients had symptomatic improvements of > or = 50%, with mean GERD-HRQL decrease of 15.0 (11.0 vs. 26.0, p < 0.001). The need for daily proton pump inhibitor (PPI) therapy was eliminated in 69% of patients at 12 months on a per-protocol basis, and 59% on an intention-to-treat basis. Adverse events included postprocedure abdominal pain (44%), shoulder pain (24%), and chest pain (17%). No long-term adverse events occurred.

CONCLUSIONS

Endoscopic full-thickness plication using multiple Plicator implants can be used safely and effectively to improve GERD symptoms and reduce medication use.

[Gastro-esophageal reflux through gastric antisecretory drugs]

During the 20th century, gastro-esophageal reflux moved from the status of a rare and severe disease to that of a frequent disease occurring mostly, in the absence of any significant lesions. Proton pump inhibitors (PPIs) are the mainstay of its therapy and are prescribed mainly in an empirical way. Extradigestive manifestations require more accurate diagnostic tests and therapeutic management. The modalities of prescription of the PPIs quickly progressed toward the on-demand therapy and over-the-counter PPIs should become widespread. The relative failures of PPIs led to a profusion of new antisecretory agents but clinical improvements are presently disappointing and the rationale of this escalation is questionable. The concept of non acid gastro-esophageal reflux opens more innovative diagnostic and therapeutic perspectives which, however, must be validated. In this respect, endoscopic treatment needs more reliable techniques and more rigorous trials. Gastro-esophageal reflux refractory to PPIs corresponds mainly to functional esophageal disorders that need diagnostic and therapeutic improvements. Barrett's esophagus constitutes a major challenge for the next few years. Its screening and its prevention seem, for the moment, inaccessible. Its survey and the prevention of its complications should benefit from progress of diagnostic and interventional endoscopy.

Pulmonary manifestations of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) may cause, trigger or exacerbate many pulmonary diseases. The physiological link between GERD and pulmonary disease has been extensively studied in chronic cough and asthma. A primary care physician often encounters patients with extra esophageal manifestations of GERD in the absence of heartburn. Patients may present with symptoms involving the pulmonary system; noncardiac chest pain; and ear, nose and throat disorders. Local irritation in the esophagus can cause symptoms that vary from indigestion, like chest discomfort and abdominal pain, to coughing and wheezing. If the gastric acid reaches the back of the throat, it may cause a bitter taste in the mouth and/or aspiration of the gastric acid into the lungs. The acid can cause throat irritation, postnasal drip and hoarseness, as well as recurrent cough, chest congestion and lung inflammation leading to asthma and/or bronchitis/ pneumonia. This clinical review examines the potential pathophysiological mechanisms of pulmonary manifestations of GERD. It also reviews relevant clinical information concerning GERD-related chronic cough and asthma. Finally, a potential management strategy for GERD in pulmonary patients is discussed.

Association of gastroesophageal reflux and O2 desaturation: a novel study of simultaneous 24-h MII-pH and continuous pulse oximetry

BACKGROUND

Proof of the relationship between gastroesophageal reflux disease (GERD) and respiratory symptoms remains a challenge. Our aim was to determine the association between reflux events and O(2) desaturation in GERD patients with primary respiratory symptoms (RS) compared to those with primary esophageal symptoms (ES) using ambulatory monitoring systems.

METHODS

One thousand eight hundred fifty-one reflux episodes were detected by multichannel intraluminal impedance (MII)-pH testing in 30 patients with symptoms of GERD (20 RS, ten ES.) All patients underwent simultaneous 24-h MII-pH and continuous O(2) saturation monitoring via pulse oximetry. Reflux-associated desaturation events were determined by correlating synchronized 24-h esophageal pH and/or impedance and O(2) desaturation.

RESULTS

One thousand one hundred seventeen reflux events occurred in patients with RS and 734 in those with ES. Nearly 60% of these 1,851 reflux events were associated with O(2) desaturation. Markedly more events were associated with O(2) desaturation in patients with RS (74.5%, 832/1,117) than in patients with ES (30.4%, 223/734, p < 0.0001). The difference in reflux desaturation association was more profound with proximal reflux--80.3% with RS vs. 29.4% with ES (p < 0.0001).

CONCLUSIONS

A remarkably high prevalence of O(2) desaturation associated with gastroesophageal reflux was noted in patients with RS. Given further study, simultaneous combined esophageal reflux and O(2) saturation monitoring may prove a useful diagnostic tool in this difficult group of patients.

The Italian validation of the Montreal Global definition and classification of gastroesophageal reflux disease

BACKGROUND AND AIMS

Recently, a Global definition and a classification of gastroesophageal reflux disease (GERD) were developed by Montreal Consensus Group, composed of international expert gastroenterologists. Guidelines and consensus documents are, however, infrequently accepted and adopted at a local level. The aim of this study was to measure the acceptance of Montreal Global definition of GERD consensus document by specialists in a single country (Italy) and to measure the linguistic, scientific, and practical differences between the international consensus document and the Italian version.

METHODS

A 2-day meeting was held in June 2007 in Rome, Italy, attended by 147 Italian physicians who were experts in gastroenterology. They reviewed the individual original statements in their Italian translation and then voted on the statement using the scoring system used by the Montreal Consensus Group (6-point Likert scale). Voting was performed at baseline and after an analytical discussion on each statement, led by six internationally renowned experts. Consensus was defined as an agreement with a statement by at least two-thirds of the group. Results were compared with the Montreal statements.

RESULTS AND DISCUSSION

The level of consensus was already extremely high at the first vote (>90% with the two-thirds threshold). The level of agreement at the second vote increased slightly. The maximum variation between two votes was 33% (of increase from first to second round, 59-92%). The high level of agreement could be because of both the general acceptance of Montreal Consensus by scientific community, and the new scientific evidences published after the Montreal report, which fit with the original statements.

CONCLUSION

This study is the first national linguistic validation of the Montreal Global definition of GERD and is also proof of its scientific validity, based on the same methodology used to create the Montreal statements. It also suggests that evidence-based International disease classification systems can be applied to local settings after validation by local experts.

Proton pump inhibitor failure--what are the therapeutic options?

Proton pump inhibitor (PPI) failure is very common and may affect up to one-third of the PPI consumers. Identifying the underlying mechanisms for PPI failure in each individual patient is essential for treatment success. For residual acid reflux, increasing the PPI dose to twice daily; switching to another PPI, or adding an histamine 2 receptor antagonist could be a successful therapeutic strategy. In patients with duodenogastroesophageal reflux, weak acidic/alkaline reflux and hypersensitivity to acid reflux, therapeutic modalities that reduce transient lower esophageal sphincter relaxation or visceral pain could be entertained. Treatment of PPI failure due to delayed gastric emptying should be focused on improving gastric motor activity. Psychological management may supplement any medical or surgical approach toward PPI failure.

Addition of pH-impedance monitoring to standard pH monitoring increases the yield of symptom association analysis in infants and children with gastroesophageal reflux

OBJECTIVE

To assess the additional yield of combined multichannel intraluminal pH-impedance (pH-MII) monitoring compared with standard pH monitoring on gastroesophageal reflux (GER) symptom associations in infants and children.

STUDY DESIGN

In 80 patients, 24-hour ambulatory pH-MII monitoring was performed. Tracings were analyzed with established pH-MII criteria. Symptoms of regurgitation and belching were excluded from analysis, because these were considered to be a direct consequence of GER. Standard GER-symptom correlation indices were calculated with: 1) standard pH monitoring; 2) MII detection of liquid and mixed bolus GER; 3) MII detection of all bolus GER (liquid, mixed, and gas); 4) pH-MII detection of all GER, including pH-only GER.

RESULTS

Fifty patients (21 children) were included. MII detection of all bolus GER yielded a significantly greater number of patients who were symptom-positive, 36 (72%) compared with 25 (50%) with standard pH-monitoring (P = .04). A positive symptom association was observed in 8 of 10 (80%) patients with pathological esophageal acid exposure and 28 of 40 (70%) patients with negative pH-findings.

CONCLUSIONS

A high proportion of patients with normal esophageal acid exposure had a positive symptom association on pH-MII monitoring. Including all MII-detected bolus GER and excluding pH-only GER for analysis optimizes the yield of GER-symptom associations in infants and children.

Review article: intra-oesophageal impedance monitoring for the assessment of bolus transit and gastro-oesophageal reflux

BACKGROUND

Intra-oesophageal impedance monitoring can be used to assess the clearance of a swallowed bolus (oesophageal transit) and to detect gastro-oesophageal reflux independent of its acidity.

AIM

To discuss the clinical application of the impedance technique for the assessment of bolus transit and gastro-oesophageal reflux.

METHODS

Review of the literature on intra-oesophageal impedance monitoring of bolus transit and gastro-oesophageal reflux.

RESULTS

Using impedance criteria, normal oesophageal bolus clearance can be defined as complete clearance of at least 80% of liquid boluses and at least 70% of viscous boluses. Impedance recording identifies oesophageal function abnormalities in non-obstructive dysphagia patients and in patients with postfundoplication dysphagia. The impedance technique seems to be less suitable for the most severe end of the dysphagia spectrum like achalasia. Intra-oesophageal impedance monitoring detects reflux events independent of the pH of the refluxate, which allows identification of non-acid reflux episodes. In addition, use of impedance monitoring enables assessment of the composition (liquid, gas, mixed) and proximal extent of the refluxate. Combined impedance-pH monitoring is more accurate than pH alone for the detection of both acid and weakly acidic reflux. Furthermore, addition of impedance monitoring to pH increases the yield of symptom association analysis both in patients off and on proton pump inhibitor therapy.

CONCLUSIONS

Intra-oesophageal impedance monitoring is a feasible technique for the assessment of bolus transit and gastro-oesophageal reflux. Combined impedance-manometry provides clinically important information about oesophageal function abnormalities and combined impedance-pH monitoring identifies the relationship between symptoms and all types of reflux events regarding acidity and composition.

Gastroesophageal reflux monitoring: pH (catheter and capsule) and impedance

Diagnostic testing for GERD has evolved to include multi esophageal sites (distal, proximal and hypopharyngeal monitoring), wireless pH, and oropharyngeal devices. The versatility of the devices has increased our ability to better understand the role of acid reflux in various disorders involving reflux of acid. Wireless pH monitoring improves patient comfort and allows monitoring for gastroesophageal reflux events over several days. Ambulatory MII-pH monitoring is another exciting diagnostic tool, which is capable of detecting more than one type of reflux and achieves higher sensitivity and specificity to detect GERD than endoscopy or pH-metry. It is useful in patients with either typical or atypical reflux symptoms who are refractory to proton pump inhibitor (PPI) therapy. In this setting, MII-pH can be performed on PPI therapy to assess the efficacy of PPIs and the role of nonacid or acid reflux in persistent symptoms.

Ambulatory monitoring of GERD: current technology

Various techniques have been devised to diagnose, characterize, and classify gastroesophageal reflux (GER). Stationary techniques, such as fluoroscopy and scintigraphy, provide interesting anatomic and functional information related to GER but are not sensitive enough and are usually performed in nonphysiologic conditions. Ambulatory techniques for GER monitoring have been developed and used since 1974. The current available techniques include catheter and wireless pH-metry, Bilitec, and impedance-pH monitoring. Prolonged wireless pH monitoring can be useful to evaluate patients off and on proton pump inhibitor (PPI) treatment. Impedance-pH monitoring is being used increasingly in patients who have persistent symptoms on PPI therapy because it can establish an association between symptoms and weakly acidic or nonacid reflux. Bilitec is performed in patients suspected to have increased duodenogastroesophageal reflux (DGER). This article discusses the technical details, clinical indications, and applications of these diagnostic techniques.

Gastroesophageal reflux disease and connective tissue disorders: pathophysiology and implications for treatment

INTRODUCTION

It has been postulated that in patients with connective tissue disorders (CTD) and gastroesophageal reflux disease (GERD), esophageal function is generally deteriorated, often with complete absence of peristalsis. This belief has led to the common recommendation of avoiding antireflux surgery for fear of creating or worsening dysphagia.

METHODS

We hypothesized that in most patients with CTD and GERD: (a) esophageal function is often preserved; (b) peristalsis is more frequently absent when end-stage lung disease (ESLD) is also present; (c) a tailored surgical approach (partial or total fundoplication) based on the findings of esophageal manometry allows control of reflux symptoms without a high incidence of postoperative dysphagia. Forty-eight patients with CTD were evaluated by esophageal manometry and 24-hour pH monitoring (EFT). Twenty patients (group A) had EFT because of foregut symptoms, and 28 patients with ESLD (group B) had EFT as part of the lung transplant evaluation. Two hundred and eighty-six consecutive patients with GERD by pH monitoring served as a control group (group C). A laparoscopic fundoplication was performed in two group A patients (total), eight group B patients (three patients total, five patients partial) and in all group C patients (total).

RESULTS

Esophageal peristalsis was preserved in all patients with CTD and GERD. In contrast, peristalsis was absent in about half of patients when ESLD was also present. A tailored surgical approach resulted in control of reflux symptoms in all patients. One patient only developed postoperative dysphagia, which resolved with two Savary dilatations.

CONCLUSION

These data show that esophageal motor function is preserved in most patients with CTD, so that they should be offered antireflux surgery early in the course of their disease to prevent esophageal and respiratory complications. In patients with ESLD in whom peristalsis is absent, a partial rather than a total fundoplication should be performed, as it allows control of reflux symptoms while avoiding postoperative dysphagia.

The role of nonacid reflux in NERD: lessons learned from impedance-pH monitoring in 150 patients off therapy

INTRODUCTION

Nonerosive reflux disease (NERD) is the most common form of gastroesophageal reflux disease. While the role of acid reflux has been established, the relevance of nonacid reflux in generating symptoms in NERD is unknown.

AIM

To evaluate the diagnostic utility of impedance-pH monitoring in NERD patients.

METHODS

Patients with typical reflux symptoms (heartburn and/or regurgitation) and normal endoscopy (NERD) underwent a combined impedance-pH monitoring off proton pump inhibitor (PPI) therapy. Previously investigated 48 healthy volunteers served as controls. Distal esophageal acid exposure (% time pH < 4), number of acid and nonacid reflux episodes, 2-min window symptom index (SI; positive if > or = 50%), and symptom association probability (SAP; positive if > or = 95%) were calculated.

RESULTS

Between June 2004 and June 2007, 150 NERD patients (82 women, mean age 48 yr, range 18-78 yr) reported symptoms during the impedance-pH monitoring. NERD patients had more reflux episodes (median [25th-75th percentile]) compared with healthy volunteers (total: 46 [26-65] vs 32 [18-43], P < 0.05; acid: 29 [14-43] vs 17 [8.5-31.0], P < 0.05; and nonacid: 20 [15-27] vs 18 [13.5-26.0], P = NS). Sixty-three (42%) patients had abnormal % time pH < 4. Among 87 patients with normal % time pH < 4., 22 (15%) had a positive SAP for acid, 19 (12%) for nonacid reflux, and 7 (5%) for both. Classifying patients with symptomatic nonacid reflux as having a hypersensitive esophagus reduced the number of patients with functional heartburn from 65 (43%) to 39 (26%).

CONCLUSION

Monitoring for nonacid reflux in NERD patients reduces the proportion of patients classified as having "functional heartburn." Studies assessing the clinical implications of these findings are warranted.

Diagnostic options for patients with refractory GERD

Patients with refractory gastroesophageal reflux disease (GERD) are those who have persistent symptoms while being treated with proton pump inhibitors (PPIs). One third of GERD patients requiring a daily PPI are estimated to eventually experience treatment failure. These patients are usually referred for further investigation to confirm the presence of GERD or to identify other entities as the cause of symptoms. Tools that can be used in this diagnostic process include upper gastrointestinal endoscopy with analysis of esophageal biopsies, esophageal pH monitoring, impedance-pH monitoring, and esophageal bilirubin monitoring. The conventional diagnostic approach includes upper gastrointestinal endoscopy and ambulatory pH monitoring while receiving PPI therapy. New diagnostic techniques that may be useful with refractory GERD include impedance-pH monitoring, which is very sensitive in detecting persistent weakly acidic reflux, and bilirubin monitoring, which detects increased esophageal exposure to bile. Gastric pH monitoring should be reserved for patients in whom PPI resistance is suspected.

Laryngeal manifestations of gastroesophageal reflux disease

Chronic laryngeal signs and symptoms associated with gastroesophageal reflux disease (GERD) are often referred to as reflux laryngitis or laryngopharyngeal reflux (LPR). It is estimated that up to 15% of all visits to otolaryngology offices are because of manifestations of LPR. Damage to laryngeal mucosa may be the result of reflux of gastroduodenal contents, whether chronic or a single incident. The most common presenting symptoms of LPR include hoarseness, sore throat, throat clearing, and chronic cough. The diagnosis of LPR is usually made on the basis of presenting symptoms and associated laryngeal signs, including laryngeal edema and erythema. The current recommendation for managing these patients is empiric therapy with twice-daily proton pump inhibitors for 1 to 2 months. Other causes of laryngeal irritation are considered in most of those who are unresponsive to such therapy. Surgical fundoplication is most effective in those who are responsive to acid-suppressive therapy.

Multichannel intraluminal impedance and pH monitoring in gastroesophageal reflux disease

The role of acid is very well established in the pathogenesis of gastroesophageal reflux disease and acid suppression constitutes the main approach to its medical treatment. With the current frequent use of proton pump inhibitors, we are seeing increasing numbers of patients in whom symptoms persist despite pharmacological acid suppression. Reflux monitoring has been traditionally performed through esophageal pH measurement to detect acid reflux (i.e., drops in esophageal pH to below 4.0). Multichannel intraluminal impedance and pH measurement constitutes an important development in reflux monitoring because, in addition to detecting acid reflux, it enables measurement of nonacid reflux (i.e., with a pH >4.0, also known as 'weakly acidic' for pH >4 but <7, or 'weakly alkaline' if pH >7), which may be responsible for symptoms in some patients who are being treated with proton pump inhibitors. This review describes the approach to measuring nonacid reflux, the possible mechanisms responsible for symptoms due to this type of reflux, the clinical importance of this phenomenon and available treatment options; and the role of multichannel intraluminal impedance and pH monitoring in the evaluation of refractory gastroesophageal reflux disease.

Prospective assessment of patient selection for antireflux surgery by combined multichannel intraluminal impedance pH monitoring

INTRODUCTION

Selecting gastroesophageal reflux disease (GERD) patients for surgery on the basis of standard 24-h pH monitoring may be challenging, particularly if this investigation does not correlate with clinical symptoms. Combined multichannel intraluminal impedance pH monitoring (MII-pH) is able to physically detect each episode of intraesophageal bolus movements, enabling identification of either acid or non-acid reflux episodes and thus establish the association of the reflux with symptoms.

MATERIALS AND METHODS

We prospectively assessed and reviewed data from 314 consecutive patients who underwent MII-pH for GERD not responsive or not compliant to proton pump inhibitor therapy. One hundred fifty-three patients with a minimum follow-up of 1 year constituted the study population. Clinical outcomes and satisfaction rate were collected in all patients who underwent laparoscopic Nissen-Rossetti fundoplication. Outcomes were reported for patients with normal and ineffective peristalsis and for patients with positive pH monitoring, negative pH monitoring and positive total number of reflux episodes at MII, and negative pH monitoring and normal number of reflux episodes at MII and a positive symptom index correlation with MII.

RESULTS

The overall patient satisfaction rate was 98.3%. No differences were recorded in the clinical outcomes of the patients with preoperative normal and ineffective peristalsis. No differences in patients' satisfaction and clinical postoperative DeMeester symptom scoring system were noted between the groups as determined by MII-pH.

CONCLUSION

MII-pH provides useful information for objective selection of patients to antireflux surgery. Nissen fundoplication provides excellent outcomes in patients with positive and negative pH and positive MII monitoring or Symptom Index association. More extensive studies are needed to definitively standardize the useful MII-pH parameters to select the patient to antireflux surgery.

High-resolution manometry and impedance-pH/manometry: valuable tools in clinical and investigational esophagology

Both high-resolution manometry (HRM) and impedance-pH/manometry monitoring have established themselves as research tools and both are now emerging in the clinical arena. Solid-state HRM capable of simultaneously monitoring the entire pressure profile from the pharynx to the stomach along with pressure topography plotting represents an evolution in esophageal manometry. Two strengths of HRM with pressure topography plots compared with conventional manometric recordings are (1) accurately delineating and tracking the movement of functionally defined contractile elements of the esophagus and its sphincters, and (2) easily distinguishing between luminal pressurization attributable to spastic contractions and that resultant from a trapped bolus in a dysfunctional esophagus. Making these distinctions objectifies the identification of achalasia, distal esophageal spasm, functional obstruction, and subtypes thereof. Ambulatory intraluminal impedance pH monitoring has opened our eyes to the trafficking of much more than acid reflux through the esophageal lumen. It is clear that acid reflux as identified by a conventional pH electrode represents only a subset of reflux events with many more reflux episodes being composed of less acidic and gaseous mixtures. This has prompted many investigations into the genesis of refractory reflux symptoms. However, with both technologies, the challenge has been to make sense of the vastly expanded datasets. At the very least, HRM is a major technological tweak on conventional manometry, and impedance pH monitoring yields information above and beyond that gained from conventional pH monitoring studies. Ultimately, however, both technologies will be strengthened as outcome studies evaluating their utilization become available.

Improved reflux monitoring in the acute gastroesophageal reflux porcine model using esophageal multichannel intraluminal impedance measurement

BACKGROUND

Acute animal models are needed to obtain further insights into the mechanism of gastroesophageal reflux disease. Existing acute models use imprecise methods to detect reflux. The aim of the present study was to evaluate the potential of esophageal multichannel intraluminal impedance measurement (MII) to improve the quality of results of acute reflux porcine models.

MATERIALS AND METHODS

MII was used in ten pigs to monitor gastroesophageal reflux. Measurements were obtained (A) before and (B) after mobilization of the esophagus and (C) after myotomy. The results were compared to those obtained when reflux was monitored by esophageal drainage of intragastrically infused blue solution (DBS).

RESULTS

The times to first appearance of reflux were 67% (A), 86% (B), and 57% (C) of those by DBS when detected by MII; p < 0.05. The respective values for intragastric pressures needed to provoke reflux were 46%, 76%, and 66%; p < 0.05. Although the lower esophageal sphincter pressure decreased by 69% after (B) the intragastric pressure needed to provoke reflux increased by 140%; p < 0.05.

CONCLUSIONS

MII improves the detection of reflux in the acute reflux porcine model. The finding that after sole mobilization of the esophagus the intragastric pressure needed to provoke reflux was increased although the finding that the pressure of the lower esophageal sphincter was decreased needs further investigation.

Reflux monitoring: current status

Gastroesophageal reflux monitoring is a key investigation in managing gastroesophageal reflux disease. Esophageal pH monitoring is used to quantify esophageal acid exposure and the association of symptoms with acidic reflux episodes. Recently available wireless pH monitoring systems allow reflux monitoring over prolonged periods and increase patient comfort during the procedure. Combined impedance-pH monitoring offers the ability to identify reflux episodes independently of their acid content, an important advantage when evaluating patients with symptoms persisting during acid-suppressive therapy.

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.

Clinical importance of impedance measurements

BACKGROUND

Because impedance changes have been shown to be a sensitive and reliable means to detect fluid or gas movement within the esophagus, numerous studies worldwide have addressed the potential for impedance determinations to provide a sensitive measure of either esophageal transit function or the presence and extent of gastroesophageal reflux. Using a catheter with multiple impedance measuring sites [multichannel intraluminal impedance (MII)] allows the opportunity to track fluid movement within the esophagus.

AIM

To review the clinical importance of impedance measurements.

CONCLUSIONS

Ambulatory MII-pH monitoring is a valuable tool in the assessment of reflux because it identifies not only acid reflux but overcomes the deficiency of simple pH monitoring by showing all reflux types, both acid and nonacid. It is our belief that MII-pH testing on proton pump inhibitor therapy has become the new "gold standard" for detection of reflux and for clarifying its relationship to symptoms.

Impedance-pH monitoring: new standard for measuring gastro-oesophageal reflux

Impedance monitoring is a new technique that can be used to detect the flow of fluids and gas through hollow viscera. With impedance monitoring gastro-oesophageal reflux can be detected independent of its acidity by differences in electrical impedance between the mucosal surface, fluids and gas that surround the catheter. Clinically, it is used in combination with oesophageal pH monitoring, and the combination of impedance-pH monitoring allows recognition of both acidic and weakly acidic reflux episodes. Studies have shown that impedance-pH monitoring is useful in the evaluation of patients with proton pump inhibitor-resistant typical reflux symptoms, as it provides a higher yield in detecting reflux as the cause of a patient's symptoms compared to pH monitoring alone. It is therefore likely that impedance-pH monitoring will largely replace pH monitoring in the next 5 years and it will become the standard for reflux detection.

Efficacy of laparoscopic mesh-augmented hiatoplasty in GERD and symptomatic hiatal hernia. Study using combined impedance-pH monitoring

BACKGROUND

Laparoscopic fundoplication is the standard antireflux procedure. However, side effects such as gas bloating indicate that the procedure is not unproblematic. Laparoscopic mesh-augmented hiatoplasty (LMAH) might be an alternative operation aimed at restoring the intra-abdominal part of the esophagus and reducing the size of the diaphragmatic hiatus.

AIM

The aim of this study was to prospectively evaluate gastroesophageal reflux disease symptoms and gastroesophageal reflux before and after LMAH using 24 h impedance-pH monitoring (MII-pH).

MATERIALS AND METHODS

Twenty patients underwent MII-pH monitoring pre- and 3 months post-LMAH. Symptoms were assessed using the Gastrointestinal Symptom Rating Scale questionnaire.

RESULTS

LMAH reduced the mean (SD) reflux syndrome score [pre-op 4.5 (1.7) vs post-op 1.4 (0.9); p<0.001], median (25th-75th percentile) distal %time pH<4 [4.9 (3.4-10.3) vs 1.0 (0.3-2.5) %; p=0.001) and total number of liquid reflux episodes [27.5 (17.5-38.3) vs 18 (7.3-29.3); p<0.05] without changing the number of gas reflux episodes [12 (6-34.3) vs 13.5 (6-20); p=0.346). All patients reported no limitation of their ability to belch.

CONCLUSION

LMAH significantly reduces reflux symptoms and esophageal acid exposure without interfering with the ability to vent gas from the stomach documented by an unchanged number of gas reflux episodes before and after LMAH.

Characteristics of symptomatic reflux episodes on Acid suppressive therapy

BACKGROUND

Persistent symptoms on acid suppressive therapy are due to either acid or nonacid gastroesophageal reflux (GER) episodes or are not related to reflux.

AIM

To compare physical and chemical characteristics of GER episodes associated with symptoms in patients on acid suppressive therapy.

METHODS

Patients with persistent symptoms on acid suppressive therapy underwent combined impedance-pH monitoring. Reflux episodes were classified as acid if nadir pH was <4.0, and nonacid if it remained at >/=4.0, separated into liquid-only or mixed (liquid-gas), and considered to reach the proximal esophagus if liquid was present 15 cm above the lower esophageal sphincter (LES). Reflux episodes were considered symptomatic if patients recorded a symptom within 5 min after the reflux episode. Risk factors of symptomatic reflux episodes were identified using multivariable generalized estimating equations (GEEs).

RESULTS

One hundred twenty patients (85 women, median age 54 yr, range 18-85 yr) recorded 3,547 reflux episodes (84.3% nonacid, 50.6% mixed), of which 468 (13.2%) were symptomatic. Based on multivariable GEE analysis with episode-level symptom status (symptomatic vs nonsymptomatic) as the outcome variable, reflux episode acidity was not significantly associated with symptoms (P= 0.40). Mixed reflux episodes were significantly associated with symptoms relative to liquid-only episodes (odds ratio [OR] 1.49, 95% confidence interval [CI] 1.19-1.87, P= 0.0005), as were reflux episodes reaching the proximal esophagus compared with those reaching the distal esophagus only (OR 1.28, 95% CI 1.06-1.55, P= 0.012).

CONCLUSION

The majority of reflux episodes on acid suppressive therapy are asymptomatic. Reflux episodes extending proximally and having a mixed (liquid-gas) composition are significantly associated with symptoms, irrespective of whether pH is acid (<4) or nonacid (>/=4).

An analysis of persistent symptoms in acid-suppressed patients undergoing impedance-pH monitoring

BACKGROUND & AIMS

Despite proton-pump inhibitors (PPIs), patients may have persistent symptoms of gastroesophageal reflux disease (GERD). We aimed to identify symptom types and frequency experienced by patients on PPI therapy, and to identify the type of reflux, if any, associated with these symptoms.

METHODS

A retrospective review was performed of 200 patients on PPI with GERD symptoms during ambulatory impedance-pH testing. The symptom index (SI) was determined for each symptom, and an SI of 50% or more was considered positive. Patients were divided into 2 groups: those with exclusively nonacid reflux (NAR) episodes and those with mixed-acid and NAR episodes. Symptom profiles were compared between these 2 groups.

RESULTS

A total of 415 symptoms were reported by the 200 patients on twice-daily PPIs. Throat clearing was most common (24%). A total of 110 (27%) were typical symptoms and 305 (73%) were atypical. Typical symptoms were more likely to have a positive SI than atypical symptoms (48% vs 25%, P < .01). Eighty-four patients (42%) had a positive SI, and 116 patients (58%) had a negative SI. One hundred patients (50%) had only NAR; the other 100 had mixed acid and NAR. Heartburn (21% vs 63%, P < .01) and nausea (8% vs 44%, P < .01) were more likely associated with reflux in the mixed-acid and NAR group.

CONCLUSIONS

Patients on PPIs still experience GERD symptoms. Impedance-pH monitoring identifies similar symptom associations with all types of reflux and also clarifies symptoms not related to any reflux.

Review article: respiratory manifestations of gastro-oesophageal reflux disease

BACKGROUND

Respiratory manifestations represent one of the most prevalent and difficult-to-manage extra-oesophageal syndromes of gastro-oesophageal reflux disease.

AIMS

To review the epidemiology, pathophysiological mechanisms and therapeutic outcomes of reflux-related respiratory disorders.

METHODS

Search of the literature published in English using PubMed database.

RESULTS

There is a discrepancy between the high prevalence of reflux in asthmatics and the limited efficacy of antireflux therapies. Asthma per se may cause reflux. Patients with difficult-to-treat asthma and/or nocturnal symptoms should be screened for reflux. Reflux can induce chronic cough through different mechanisms including micro-aspiration and both local and central reflexes. Cough and reflux may precipitate each other. A meta-analysis found no significant difference between placebo and proton pump inhibitors in the resolution of cough. Encouraging results have been reported, following antireflux surgery in patients selected on the basis of pH-impedance monitoring. Attention has been drawn to obstructive sleep apnoea syndrome.

CONCLUSIONS

The role of gastro-oesophageal reflux disease in the pathogenesis of miscellaneous respiratory disorders has been discussed for decades and established in asthma and cough. However, no major therapeutic advances have been reported recently. Future trials should concentrate on patient selection and the control of efficacy using recently developed technologies, such as pH-impedance monitoring.

Esophageal impedance-pH monitoring

Classical techniques like endoscopy and esophageal pH-metry are routinely used to study patients with symptoms related to gastroesophageal reflux disease (GERD). Although these techniques have been useful over the years both for diagnosis and therapeutic guidance, there are still many patients with typical or atypical GERD symptoms with normal endoscopy and pH-metry that do not respond adequately to antisecretory therapy. Ambulatory esophageal impedance-pH monitoring is a new technique that can be used to evaluate all types of gastroesophageal reflux, achieving higher rates of sensitivity and specificity than standard techniques. This review describes esophageal impedance-pH monitoring, summarizing the current literature on validation studies and clinical application.

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.

Review article: The measurement of non-acid gastro-oesophageal reflux

BACKGROUND

Oesophageal pH monitoring has been used for three decades to study gastro-oesophageal reflux, but it does not allow detection of non-acid reflux episodes.

AIM

To discuss the techniques by which non-acid reflux can be measured and to evaluate the clinical relevance of such measurements.

METHODS

Review of the literature on non-acid reflux monitoring.

RESULTS

Ambulatory oesophageal impedance monitoring (using a catheter with ring electrodes) allows one to detect all types of gastro-oesophageal reflux, acid as well as non-acid. Measurement of intra-oesophageal bilirubin concentration also detects reflux irrespective of the pH, but only when there is bilirubin in the gastric juice and technical short-comings limit the applicability of this technique. In untreated subjects, about 50% of reflux episodes are non-acid (nadir pH > 4). In patients on acid inhibition, up to 95% of reflux episodes are non-acid. Treatment with an acid inhibitor leads to a significant decrease in the incidence of acid reflux episodes, but not to a reduction in the total number of reflux episodes. This shift is associated with a shift in symptoms from heartburn to regurgitation. With impedance monitoring, the temporal association between symptoms that persist during inhibition of acid secretion and non-acid reflux events can be demonstrated. In a proportion of patients with chronic cough, the coughing episodes are preceded by non-acid reflux.

CONCLUSIONS

Intraluminal impedance monitoring of gastro-oesophageal reflux is a feasible technique, which provides clinically important information about the relationships between symptoms and non-acid reflux events.

Clinical trial: persistent gastro-oesophageal reflux symptoms despite standard therapy with proton pump inhibitors - a follow-up study of intraluminal-impedance guided therapy

BACKGROUND

Persistent gastro-oesophageal reflux disease (GERD), despite proton pump inhibitor (PPI) therapy, is a common problem. Combined pH/impedance monitoring (pH/MII) enables detection of reflux episodes. Aim To identify patients with objective episodes of persistent reflux and second, to evaluate the effect of modified therapy based on the results of pH/MII.

METHODS

In all, 143 patients were examined with pH/MII because of GERD-symptoms resistant to PPI-therapy. Patients with pathological pH/MII (group 1) and with normal results (group 2) were identified. Therapy modifications were evaluated after a minimum follow-up of 3 months.

RESULTS

In 56 of 143 (39.1%) patients, pathological findings in pH/MII were identified. Therapy was escalated in 33/52 patients (group 1) and in 30/71 patients (group 2). Escalating therapy led to symptomatic relief in 90.9% of the patients in group 1 and 43.3% of the patients in group 2 (P < 0.001).

CONCLUSIONS

GERD symptoms refractory to PPI-therapy could be objectively identified with pH/MII in almost 40% of all patients. Furthermore, escalating anti-reflux therapy if pH/MII was pathological is associated with a significantly higher rate of successful treatment compared to the patients with normal findings. Therefore, pH/MII facilitates a more focussed therapeutical approach to patients with PPI-resistant GERD.

Prospective study examining the impact of multichannel intraluminal impedance on antireflux surgery

BACKGROUND

Reflux monitoring using combined multichannel intraluminal impedance (MII) and pH-metry increases the sensitivity for identifying gastroesophageal reflux episodes. The likelihood of a positive symptom index (SI) for patients with reflux disease (gastroesophageal reflux disease [GERD] or nonerosive reflux disease [NERD]) receiving proton pump inhibitor (PPI) treatment has been used to select candidates for antireflux surgery. Little is known about the advantages of MII-pH monitoring compared with pH monitoring alone for evaluating GERD/NERD patients off PPI treatment considered as candidates for antireflux surgery or for assessing changes in MII-pH-detected reflux episodes after antireflux surgery. This study aimed to determine the additional value of MII over pH-metry alone for patients off PPI treatment before and after antireflux surgery.

METHODS

For this study 12 patients (4 women and 8 men; mean age, 45 years; range, 27-74 years) were evaluated using ambulatory MII-pH monitoring before and 3 months after mesh-augmented hiatoplasty. Reflux events were identified by MII-pH (A) and pH-metry (B) as patients recorded symptoms on a data logger. For each symptom, a symptom index was calculated for reflux events identified by MII-pH and by pH-monitoring alone.

RESULTS

Preoperatively, MII-pH monitoring identified 71.9 +/- 8.4 reflux episodes, whereas pH monitoring identified only 51.0 +/- 7.8 (p < 0.05). Postoperatively, MII-pH monitoring identified 35.5 +/- 6.6 reflux episodes, whereas pH monitoring identified only 19.6 +/- 4.7 (p < 0.05). The pre- and postoperative symptom index for MII-pH monitoring was higher than pH monitoring (preoperative 91.7% vs 25%, p = 0.006; postoperative 50% vs 16.7%, p = 0.012).

CONCLUSION

Combined MII-pH-metry improves the pre- and postoperative assessment of GERD patients off PPI and results in a higher symptom-reflux association.

Review article: the role of surgery in gastro-oesophageal reflux disease

BACKGROUND

Rates for laparoscopic fundoplication are declining in the United States and there is no consensus on the indications for referral to surgery in gastro-oesophageal reflux disease.

AIM

To highlight recent studies on the outcomes of laparoscopic fundoplication in adults that cast doubt on the traditional indications for surgery in reflux disease.

RESULTS

Patients who are well maintained on medical therapy have more to lose with surgical intervention than to gain, and should not be offered surgery. Likewise, the notion that surgery prevents oesophageal cancer is a hypothesis that is not supported by current evidence, therefore surgical intervention should not be offered to these patients. The only clear-cut candidates for surgery include: patients with anatomic abnormalities such as a large hiatus hernia, or those with persistent regurgitation that causes troublesome symptoms despite medical therapy; and carefully selected patients with extra-oesophageal disorders who have symptoms of reflux disease such as heartburn and regurgitation, an incomplete response to medical therapy and persistent plus demonstrable reflux on pH or impedance testing that is associated with their symptoms. Patients should be aware of the high likelihood of needing continued acid inhibitory therapy following surgery and the possibility of side-effects.

CONCLUSION

Only a few carefully selected patients should undergo fundoplication for reflux disease.

Review article: acidity and volume of the refluxate in the genesis of gastro-oesophageal reflux disease symptoms

BACKGROUND

A number of mechanisms, other than acid reflux, may be responsible for the symptoms of gastro-oesophageal reflux disease.

AIM

To assess the importance of non-acid reflux mechanisms.

METHODS

This review is based on presentations and discussion at a workshop, where specialists in the field analysed data relating to these mechanisms.

RESULTS

Weakly acidic reflux, pH (4-7), detected with impedance-pHmetry is associated with regurgitation and atypical gastro-oesophageal reflux disease symptoms. It is not clear whether pepsin and trypsin can elicit symptoms, but bile can elicit heartburn. The magnitude of reflux-induced oesophageal distension can be determined by high frequency ultrasonography and is not reduced by proton pump inhibition, suggesting that persisting symptoms 'on' a proton pump inhibitor may still be due to oesophageal distension by non-acidic reflux. Exaggerated longitudinal muscle contraction can induce non-acid-related heartburn. Preliminary studies showed a positive effect of baclofen, surgery or endoscopic procedures to reduce weakly acidic reflux.

CONCLUSION

Mechanisms other than acid reflux are involved in some of the symptoms of gastro-oesophageal reflux disease. Controlled outcome studies are needed to clarify their roles and the indications for antireflux procedures in patients with persistent symptoms whilst 'on' a proton pump inhibitor.

Improved diagnosis of gastro-oesophageal reflux in patients with unexplained chronic cough

BACKGROUND

Symptoms, oesophageal pHmetry and proton pump inhibitor treatment are used for diagnosing gastro-oesophageal reflux-related cough. Weakly acidic reflux is now increasingly associated with reflux symptoms such as regurgitation or chest pain.

AIM

To study the association between weakly acidic reflux and cough in a selected, large group of patients with unexplained chronic cough.

METHODS

A total of 100 patients with chronic cough (77 'off' and 23 'on' a proton pump inhibitor) were studied using impedance-pHmetry for reflux detection and manometry for objective cough monitoring. Symptom Association Probability (SAP) Analysis characterized the reflux-cough association.

RESULTS

Acid reflux could be a potential mechanism for cough in 45 patients (with either heartburn, high acid exposure or +SAP for acid reflux). Weakly acidic reflux could be a potential mechanism for cough in 24 patients (with either increased oesophageal volume exposure, increased number of weakly acidic reflux or +SAP for weakly acidic reflux). Reflux could not be identified as a potential mechanism for cough in 31 patients.

CONCLUSION

A positive association between cough and weakly acidic reflux was found in a significant subgroup of patients with unexplained chronic cough. Impedance-pH-manometry identified patients in whom cough can be related to reflux that would have been disregarded using the standard diagnostic criteria for acid reflux.

Review article: complete gastro-oesophageal reflux monitoring - combined pH and impedance

Gastroesophagel reflux disease (GERD) is a common condition encountered in clinical practice. Over the years there has been a continuous interaction between the understanding of the disease, the diagnostic tools and treatments of GERD. The use of proton pump inhibitor (PPI) trials by primary care physicians as diagnostic tool in patients with symptoms suspected to be due to GERD has led to a shift in the type of patients referred to specialists. Currently, gastrointestinal specialists are frequently asked to evaluate patients with persistent reflux symptoms despite acid suppressive therapy. In these patients symptoms can be associated with reflux (both acid and non-acid) or not associated with reflux. While conventional pH monitoring can quantify esophageal acid exposure and evaluate the association between symptoms and acid reflux, it cannot reliably detect reflux episodes with a pH > 4 (i.e. non-acid reflux). Detecting reflux episodes by changes in intraluminal resistance to alternating current (i.e. impedance), combined multichannel intraluminal impedance and pH (MII-pH) monitoring offers the opportunity to detect both acid and non-acid reflux episodes and to evaluate the relationship between symptoms and reflux. We believe that MII-pH monitoring has become the new ''gold standard'' for clarifying the mechanisms of persistent symptom on PPI therapy.