Characterization of reflux events after fundoplication using combined impedance-pH recording

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.

Ambulatory reflux monitoring for diagnosis of gastro-esophageal reflux disease: Update of the Porto consensus and recommendations from an international consensus group

BACKGROUND

An international group of experts evaluated and revised recommendations for ambulatory reflux monitoring for the diagnosis of gastro-esophageal reflux disease (GERD).

METHODS

Literature search was focused on indications and technical recommendations for GERD testing and phenotypes definitions. Statements were proposed and discussed during several structured meetings.

KEY RESULTS

Reflux testing should be performed after cessation of acid suppressive medication in patients with a low likelihood of GERD. In this setting, testing can be either catheter-based or wireless pH-monitoring or pH-impedance monitoring. In patients with a high probability of GERD (esophagitis grade C and D, histology proven Barrett's mucosa >1 cm, peptic stricture, previous positive pH monitoring) and persistent symptoms, pH-impedance monitoring should be performed on treatment. Recommendations are provided for data acquisition and analysis. Esophageal acid exposure is considered as pathological if acid exposure time (AET) is greater than 6% on pH testing. Number of reflux episodes and baseline impedance are exploratory metrics that may complement AET. Positive symptom reflux association is defined as symptom index (SI) >50% or symptom association probability (SAP) >95%. A positive symptom-reflux association in the absence of pathological AET defines hypersensitivity to reflux.

CONCLUSIONS AND INFERENCES

The consensus group determined that grade C or D esophagitis, peptic stricture, histology proven Barrett's mucosa >1 cm, and esophageal acid exposure greater >6% are sufficient to define pathological GERD. Further testing should be considered when none of these criteria are fulfilled.

The dynamics of the oesophageal squamous epithelium 'normalisation' process in patients with gastro-oesophageal reflux disease treated with long-term acid suppression or anti-reflux surgery

BACKGROUND

Proton pump inhibitors and laparoscopic anti-reflux surgery (LARS) offer long-term symptom control to patients with gastro-oesophageal reflux disease (GERD).

AIM

To evaluate the process of 'normalisation' of the squamous epithelium morphology of the distal oesophagus on these therapies.

METHODS

In the LOTUS trial, 554 patients with chronic GERD were randomised to receive either esomeprazole (20-40 mg daily) or LARS. After 5 years, 372 patients remained in the study (esomeprazole, 192; LARS, 180). Biopsies were taken at the Z-line and 2 cm above, at baseline, 1, 3 and 5 years. A severity score was calculated based on: papillae elongation, basal cell hyperplasia, intercellular space dilatations and eosinophilic infiltration. The epithelial proliferative activity was assessed by Ki-67 immunohistochemistry.

RESULTS

A gradual improvement in all variables over 5 years was noted in both groups, at both the Z-line and 2 cm above. The severity score decreased from baseline at each subsequent time point in both groups (P < 0.001, all comparisons), attaining a normal level by 5 years. Corresponding decreases in Ki-67 expression were observed (P < 0.001, all comparisons). No significant differences were found between esomeprazole treatment and LARS. Neither baseline severity score nor Ki-67 expression predicted the risk of treatment failure.

CONCLUSIONS

Five years of treatment is generally required before squamous epithelial cell morphology and proliferation are 'normalised' in patients with chronic GERD, despite endoscopic and symptomatic disease control. Control of the acid component of the refluxate seems to play the predominant role in restoring tissue morphology.

Factors associated with nonresponse to proton pump inhibitors therapy in patients referred for esophageal pH-impedance monitoring

Nonresponse to proton pump inhibitors (PPI) concerns up to 40% of patients treated for gastroesophageal reflux disease (GERD). Identifying predictive factors of nonresponse might help to optimize patients' treatment. The aim of this study was to determine clinical factors associated with nonresponse to PPI therapy in patients referred for pH-impedance monitoring. One hundred and sixty-eight consecutive patients (105 females, mean age 52 years, range 17-83) were included between October 2011 and May 2013. Before the realization of high-resolution manometry and 24-hour pH-impedance monitoring they completed a questionnaire including Rome III criteria for functional dyspepsia and irritable bowel syndrome (IBS). Comparisons between patients with and without PPI response were performed using chi-square or analysis of variance tests. One hundred and twenty-six patients (83%) were considered as PPI nonresponders and 26 (17%) as responders. No significant difference was observed for age and body mass index. No manometric and pH-impedance profiles were identified as associated with PPI response. The percentage of patients with functional dyspepsia and IBS was higher in PPI nonresponders patients than in responders (65.6% and 27.2%, respectively, vs. 38.5% and 7.7%, P = 0.01 and P = 0.03). This study confirms that functional digestive disorders are more frequent in patients with persistent GERD symptoms on PPI and they might be indicative of nonresponse to PPI therapy.

GERD phenotypes from pH-impedance monitoring predict symptomatic outcomes on prospective evaluation

BACKGROUND

Combinations of reflux parameters (acid exposure time, AET; symptom association probability, SAP) on pH-impedance monitoring describe varying confidence in reflux evidence. We compared outcomes between phenotypes with distinct pre-identified reflux parameters.

METHODS

In this observational cohort study, patients undergoing pH-impedance testing over a 5-year period were phenotyped by strength of reflux evidence as strong (abnormal AET, positive SAP), good (abnormal AET, negative SAP), reflux hypersensitivity (RH, normal AET, positive SAP), and equivocal evidence of reflux, and compared to two historical institutional pH monitoring cohorts. Symptom burden (dominant symptom intensity, DSI; global symptom severity, GSS) was assessed by questionnaire at baseline and on prospective follow-up and compared between phenotypes.

KEY RESULTS

Of 94 patients tested off proton pump inhibitor (PPI) therapy, baseline symptom burden was highest with strong reflux evidence and lowest when equivocal (DSI: p = 0.01; GSS: p = 0.03 across groups). After 3.1 ± 0.2 years follow-up, symptomatic improvement with surgical or medical therapy was highest with strong or good evidence, and lowest when equivocal (DSI: p = 0.008; GSS: p = 0.005 across groups). This was most pronounced for typical symptoms (DSI: p = 0.001; GSS: 0.016 across groups), but not atypical symptoms (DSI: p = 0.6; GSS: p = 0.2). For testing on PPI therapy, only GSS followed a similar trend (GSS: p = 0.057, DSI: p = 0.3). Compared to historical cohorts with pH monitoring alone, equivocal evidence for reflux was partly replaced by RH, especially off PPI (p < 0.0001).

CONCLUSIONS & INFERENCES

Phenotyping gastroesophageal reflux disease by the strength of reflux evidence on pH-impedance testing off PPI efficiently stratifies symptomatic outcome, especially for typical symptoms, and could be useful in planning management.

Parameters on esophageal pH-impedance monitoring that predict outcomes of patients with gastroesophageal reflux disease

BACKGROUND & AIMS

pH-impedance monitoring detects acid and nonacid reflux events, but little is known about which parameters predict outcomes of different management strategies. We evaluated a cohort of medically and surgically managed patients after pH-impedance monitoring to identify factors that predict symptom improvement after therapy.

METHODS

In a prospective study, we followed up 187 subjects undergoing pH-impedance testing from January 2005 through August 2010 at Washington University in St. Louis, Missouri (mean age, 53.8 ± 0.9 y; 70.6% female). Symptom questionnaires assessed dominant symptom intensity (DSI) and global symptom severity (GSS) at baseline and at follow-up evaluation. Data collected from pH impedance studies included acid exposure time (AET), reflux exposure time (RET) (duration of impedance decrease 5 cm above lower esophageal sphincter, reported as the percentage of time similar to AET), symptom reflux correlation (symptom index and symptom association probability [SAP]), and the total number of reflux events. Univariate and multivariate analyses were performed to determine factors associated with changes in DSI and GSS after therapy.

RESULTS

Of the study subjects, 49.7% were tested on proton pump inhibitor (PPI) therapy and 68.4% were managed medically. After 39.9 ± 1.3 months of follow-up, DSI and GSS scores decreased significantly (P < .05). On univariate analysis, an abnormal AET predicted decreased DSI and GSS scores (P ≤ .049 for each comparison); RET and SAP from impedance-detected reflux events (P ≤ .03) also were predictive. On multivariate analysis, abnormal AET consistently predicted symptomatic outcome; other predictors included impedance-detected SAP, older age, and testing performed off PPI therapy. Abnormal RET, acid symptom index, or SAP, and numbers of reflux events did not independently predict a decrease in DSI or GSS scores.

CONCLUSIONS

Performing pH-impedance monitoring off PPI therapy best predicts response to antireflux therapy. Key parameters with predictive value include increased AET, and correlation between symptoms and reflux events detected by impedance.

Long-term results of electrical stimulation of the lower esophageal sphincter for treatment of proximal GERD

INTRODUCTION

Electrical stimulation of the lower esophageal sphincter (LES) in gastroesophageal reflux disease (GERD) patients, using EndoStim(®) LES stimulation system (EndoStim BV, the Hague, Netherlands), enhances LES pressure, decrease distal esophageal acid exposure, improves symptoms, and eliminates the need in many patients for daily GERD medications.

AIM

To evaluate, in a post hoc analysis, the effect of LES stimulation on proximal esophageal acid exposure in a subgroup of patients with abnormal proximal esophageal acid exposure.

METHODS

Nineteen patients (median age 54 years; IQR 47-64; men-10) with GERD partially responsive to proton pump inhibitors (PPI), hiatal hernia ≤ 3 cm, esophagitis ≤ LA grade C underwent laparoscopic implantation of the LES stimulator. LES stimulation at 20 Hz, 215 μs, 5-8 m Amp sessions was delivered in 6-12, 30 min sessions each day. Esophageal pH at baseline and after 12-months of LES stimulation was measured 5 and 23 cm above the manometric upper border of LES.

RESULTS

Total, upright and supine values of median (IQR) proximal esophageal pH at baseline were 0.4 (0.1-1.4), 0.6 (0.2-2.3), and 0 (0.0-0.2) %, respectively, and at 12 months on LES-EST were 0 (0-0) % (p = 0.001 total and upright; p = 0.043 supine comparisons). 24-hour distal esophageal acid exposure improved from 10.2 (7.6-11.7) to 3.4 (1.6-7.0) % (p = 0.001). Seven (37%) patients had abnormal (>1.1%) 24-hour proximal acid exposure at baseline; all normalized at 12 months (p = 0.008). In these 7 patients, total, upright, and supine median proximal acid exposure values at baseline were 1.7 (1.3-4.1), 2.9 (1.9-3.7), and 0.3 (0-4.9) %, respectively, and after 12 months of LES-EST were 0 (0-0.0), 0 (0-0.1), and 0 (0-0) % (p = 0.018 total and upright; p = 0.043 supine comparisons). Distal esophageal pH for this group improved from 9.3 (7.8-17.2) at baseline to 3.2 (1.1-3.7) % at 12-months (p = 0.043). There were no GI side effects such as dysphagia, gas-bloat or diarrhea or device or procedure related serious adverse events with LES-EST. There was also a significant improvement in their GERD-HRQL scores.

CONCLUSION

LES-EST is associated with normalization of proximal esophageal pH in patients with GERD and may be useful in treating those with proximal GERD. The LES-EST is safe without typical side effects associated with traditional antireflux surgery.

Acid-based parameters on pH-impedance testing predict symptom improvement with medical management better than impedance parameters

OBJECTIVES

pH-impedance testing detects reflux events irrespective of pH, but its value in predicting treatment outcome is unclear. We prospectively evaluated subjects treated medically after pH-impedance testing to determine predictors of symptom improvement.

METHODS

Subjects referred for pH-impedance testing completed questionnaires in which dominant symptoms and global symptom severity (GSS) were recorded. Acid-reflux parameters (acid-exposure time, AET; symptom association by Ghillebert probability estimate, GPE; symptom index, SI) and impedance reflux parameters (reflux-exposure time, RET; number of reflux events; GPE and SI with impedance data) were extracted. Symptoms and GSS were prospectively reevaluated after medical therapy. Univariate and multivariate analyses determined predictors of GSS improvement following medical management.

RESULTS

Over 5 years, 128 subjects (mean 53.3±1.3 years, 66.4% female; typical symptoms 57.0%, 53.9% tested on therapy) underwent pH-impedance testing and subsequent medical therapy for reflux symptoms, and completed required questionnaires. On follow-up 3.35±0.14 years later, mean GSS declined by 45.0%, with 42.2% patients reporting ≥50% GSS improvement. On univariate analysis, total AET, AET≥4.0%, and GPE for all reflux events predicted both linear and ≥50% GSS improvement, but RET and number of reflux events did not. On multivariate analysis, controlling for testing on or off therapy, only AET (P=0.003) and GPE for all reflux events (P=0.029) predicted GSS improvement.

CONCLUSIONS

Acid-based reflux parameters offer greater value over impedance-based nonacid-reflux parameters in predicting symptomatic responses to proton pump inhibitor (PPI) therapy. Our findings support conducting pH-impedance studies off PPI therapy to maximize clinical utility in predicting outcome.

The impact of reflux burden on Pseudomonas positivity in children with cystic fibrosis

OBJECTIVES

Nonacid gastroesophageal reflux (GER), particularly in patients taking acid suppression, has been implicated as a cause of respiratory infections. We hypothesize that children with cystic fibrosis (CF) and a higher nonacid reflux burden have greater rates of Pseudomonas aeruginosa (Pa) infection than patients with a lower reflux burden.

STUDY DESIGN

We reviewed the multichannel intraluminal impedance (pH-MII) tracings of 35 patients with CF between 2003 and 2010. We compared the reflux profiles between those patients who were Pa positive and Pa negative.

RESULTS

The mean age was 13.5 ± 5.8 years. Twenty-seven patients (76%) were Pa positive. Ninety seven percent of patients were taking proton pump inhibitors during pH-MII testing. The mean percentage of time pH was <4 was 8.5 ± 12%. Pa patients had a significantly higher total, acid and proximal nonacid reflux burden (P < 0.009). There was a negative correlation between nonacid reflux burden and FEV1 (r = -0.397, P = 0.03) and between total number of reflux events and FEV1 (r = -0.474, P = 0.009). After adjusting for age and FEV1, total reflux burden remains significantly associated with Pa positivity (P = 0.055).

CONCLUSIONS

Increased reflux burden may predispose patients to Pa infection and worse lung function.

Reflux and belching after 270 degree versus 360 degree laparoscopic posterior fundoplication

OBJECTIVE

To investigate differences in effects of 270 degrees (270 degrees LPF) and 360 degrees laparoscopic posterior fundoplication (360 degrees LPF) on reflux characteristics and belching.

BACKGROUND

Three hundred sixty degrees LPF greatly reduces the ability of the stomach to vent ingested air by gastric belching. This frequently leads to postoperative symptoms including inability to belch, gas bloating and increased flatulence. Two hundred seventy degrees LPF allegedly provides less effective reflux control compared with 360 degrees LPF, but theoretically may allow for gastric belches (GBs) with a limitation of gas-related symptoms.

METHODS

Endoscopy, stationary esophageal manometry, and 24-hour impedance-pH monitoring off PPIs was performed before and 6 months after fundoplication for PPI-refractory gastroesophageal reflux disease (n = 14 270 degrees LPF vs. n = 28 360 degrees LPF). GBs were defined as gas components of pure gas and mixed reflux episodes reaching the proximal esophagus. Absolute reductions (Δ) were compared.

RESULTS

Reflux symptoms and the 24-hour incidence of acid (Δ -77.6 vs. -76.7), weakly acidic (Δ -9.4 vs. -6.6), liquid (Δ -59.0 vs. -49.8) and mixed reflux episodes (Δ -28.0 vs. -33.5) were reduced to a similar extent after 270° LPF and 360° LPF, respectively. The reduction in proximal, mid-esophageal and distal reflux episodes were similar in both groups as well. Persistent symptoms were not related to acid or weakly acidic reflux. Two hundred seventy degrees LPF had no significant impact on the number of gas reflux episodes (Δ -3.6; P = 0.363), whereas 360 degrees LPF significantly reduced gas reflux episodes (Δ -17.0; P = 0.002). After 270 degrees LPF, GBs (Δ -29.3 vs. -50.6; P = 0.026) were significantly less reduced and the prevalence of gas bloating (7.1% vs. 21.4%; P = 0.242) and increased flatulence (7.1% vs. 42.9%; P = 0.018) was lower compared to 360 degrees LPF. Twenty-eight patients (67%) showed supragastric belches (SGBs) before and after surgery. The increase in SGBs without reflux (Δ +32.4 vs. +25.5) and the decrease in reflux-associated SGBs (Δ -12.1 vs. -14.0) were similar after 270 degrees LPF and 360 degrees LPF.

CONCLUSIONS

Two hundred seventy degrees LPF and 360 degrees LPF alter the belching pattern by reducing GBs (air venting from stomach) and increasing SGBs (no air venting from stomach). However, gas reflux and GBs are reduced less after 270 degrees LPF than after 360 degrees LPF, resulting in more air venting from the stomach and less gas bloating and flatulence, whereas reflux is reduced to a similar extent in the short-term.

Reflux parameters as modified by EsophyX or laparoscopic fundoplication in refractory GERD

BACKGROUND

EsophyX is a novel transoral incisionless fundoplication device developed to mimic surgical fundoplication. EsophyX fundoplication improves acid reflux parameters in proton pump inhibitor (PPI)-responsive GERD patients but its efficacy in refractory GERD has been scarcely studied.

AIM

To assess reflux parameters before and after EsophyX or laparoscopic fundoplication and their relationship with symptoms in refractory GERD.

METHODS

In an open-label study, we enrolled prospectively patients with heartburn/regurgitation persisting despite high-dose PPI therapy. Impedance-pH monitoring was performed on PPI therapy before intervention and off PPI therapy 3 months after intervention.

RESULTS

Ten patients chose to undergo EsophyX (EndoGastric Solutions, Redmond, WA, USA) fundoplication while ten chose laparoscopic fundoplication, and the baseline characteristics were comparable. Distal and proximal refluxes were significantly reduced post-operatively in the surgical but not in the endoscopic group and the median values were significantly lower in the former than in the latter. The oesophageal acid exposure time was normal in 50% of cases after EsophyX and in 100% of cases after surgery (P=0.033); the number of distal refluxes was normal in 20% and 90% of cases (P=0.005) and the number of proximal refluxes was normal in 40% and 100% of cases (P=0.011), respectively. A positive persisting symptom-reflux association was found post-operatively in 6/10 patients in the EsophyX group and in 0/10 patients in the surgical group (P=0.011).

CONCLUSIONS

In patients with refractory GERD, EsophyX fundoplication is significantly less effective than laparoscopic fundoplication in improving reflux parameters and accordingly, in inducing symptom remission.

Reflux parameters as modified by laparoscopic fundoplication in 40 patients with heartburn/regurgitation persisting despite PPI therapy: a study using impedance-pH monitoring

BACKGROUND

Patients with typical reflux symptoms (heartburn/regurgitation) persisting despite proton pump inhibitor (PPI) therapy are not uncommon. Impedance-pH monitoring detects gastroesophageal reflux at all pH levels and may establish if ongoing symptoms on PPI therapy are associated with acid/nonacid reflux. Laparoscopic fundoplication is a therapeutic option in such patients but reflux parameters on PPI therapy and after intervention and their relationship with symptom persistence/remission have been scarcely studied.

AIMS

The aim of this study was to assess reflux parameters and their relationship with symptoms before and after laparoscopic fundoplication, on and off PPI therapy, respectively, in patients with PPI-unresponsive heartburn/regurgitation and with a positive symptom-reflux association and/or abnormal reflux parameters detected on PPI therapy.

METHODS

Impedance-pH monitoring was performed on high-dose PPI therapy and 3 months after laparoscopic fundoplication, off PPI therapy, in 40 patients with PPI-unresponsive heartburn/regurgitation. Symptoms were scored by a validated questionnaire.

RESULTS

Esophageal acid exposure time as well as the number of total and proximal reflux events and of acid and weakly acidic refluxes decreased significantly after surgery: normal values were found in 100, 77, 95, 92 and 65% of cases, respectively. Weakly alkaline refluxes increased significantly postoperatively but neither before nor after intervention were associated with symptoms. All patients reported total/subtotal remission of heartburn/regurgitation 3 months after surgery.

CONCLUSIONS

Laparoscopic fundoplication improves acid and weakly acidic reflux parameters when compared with PPI therapy. This improvement justifies the very high post-surgical symptom remission rate that we observed. Prolonged follow-up is warranted but our findings strongly support the surgical option in PPI failures.

Guidelines for the diagnosis and management of gastroesophageal reflux disease: an evidence-based consensus

Gastroesophageal reflux disease (GERD) is one of the most common disorders in medical practice. A number of guidelines and recommendations for the diagnosis and management of GERD have been published in different countries, but a Brazilian accepted directive by the standards of evidence-based medicine is still lacking. As such, the aim of the Brazilian GERD Consensus Group was to develop guidelines for the diagnosis and management of GERD, strictly using evidence-based medicine methodology that could be clinically used by primary care physicians and specialists and would encompass the needs of physicians, investigators, insurance and regulatory bodies. A total of 30 questions were proposed. Systematic literature reviews, which defined inclusion and/or exclusion criteria, were conducted to identify and grade the available evidence to support each statement. A total of 11,069 papers on GERD were selected, of which 6,474 addressed the diagnosis and 4,595, therapeutics. Regarding diagnosis, 51 met the requirements for the analysis of evidence-based medicine: 19 of them were classified as grade A and 32 as grade B. As for therapeutics, 158 met the evidence-based medicine criteria; 89 were classified as grade A and 69 as grade B. In the topic Diagnosis, answers supported by publications grade A and B were accepted. In the topic Treatment only publications grade A were accepted: answers supported by publications grade B were submitted to the voting by the Consensus Group. The present publication presents the most representative studies that responded to the proposed questions, followed by pertinent comments. Follow examples. In patients with atypical manifestations, the conventional esophageal pH-metry contributes little to the diagnosis of GERD. The sensitivity, however, increases with the use of double-channel pH-metry. In patients with atypical manifestations, the impedance-pHmetry substantially contributes to the diagnosis of GERD. The examination, however, is costly and scarcely available in our country. The evaluation of the histological signs of esophagitis increases the diagnostic probability of GERD; hence, the observation of the dimensions of the intercellular space of the esophageal mucosa increases the probability of diagnostic certainty and also allows the analysis of the therapeutic response. There is no difference in the clinical response to the treatment with PPI in two separate daily doses when compared to a single daily dose. In the long term (>1 year), the eradication of H. pylori in patients with GERD does not decrease the presence of symptoms or the high recurrence rates of the disease, although it decreases the histological signs of gastric inflammation. It seems very likely that there is no association between the eradication of the H. pylori and the manifestations of GERD. The presence of a hiatal hernia requires larger doses of proton-pump inhibitor for the clinical treatment. The presence of permanent migration from the esophagogastric junction and the hernia dimensions (>2 cm) are factors of worse prognosis in GERD. In this case, hiatal hernias associated to GERD, especially the fixed ones and larger than 2 cm, must be considered for surgical treatment. The outcomes of the laparoscopic fundoplication are adequate.

New developments in reflux-associated cough

Gastro-oesophageal reflux disease (GORD) is generally considered one of the three main causes of chronic cough, along with asthma and nasal disease. The diagnosis of GORD is often based upon a successful trial of anti-acid treatment however GORD is a complex condition taking many forms. Only recently have studies started to address the different types of GORD in patients with chronic cough and how these may infer the mechanisms linking these common conditions. GORD can be assessed in a number of ways; whilst endoscopy provides evidence of oesophagitis (i.e. erosive disease), 24-h ambulatory oesophageal pH monitoring may demonstrate abnormal oesophageal acid exposure in the absence of oesophageal damage (i.e. non-erosive disease). The development of oesophageal impedance monitoring now allows the assessment of all reflux events (regardless of degree of acidity) and further classification of reflux by the proximal extension e.g. to upper oesophagus or even pharynx. Chronic cough patients may still be considered to have GORD if there is a significant temporal association between reflux events and coughing. Recent studies have examined the relationships between cough and reflux events, the roles of distal and proximal/pharyngeal reflux and also micro-aspiration in chronic cough patients. Increasing evidence suggests a significant proportion of patients display statistical associations between reflux and cough events, in the absence of an excessive numbers of reflux events either within or outside of the oesophagus.

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.

Recurrent symptoms after fundoplication with a negative pH study--recurrent reflux or functional heartburn?

INTRODUCTION

A small cohort of patients present after antireflux surgery complaining of recurrent heartburn. Over two thirds of these patients will have a negative 24-h pH study. The aim of our study is to determine whether these patients have an associated functional disorder or abnormal cytokine activity and to examine the reproducibility of pH testing.

METHODS

A prospective analysis was carried out on a cohort of patients who had undergone a fundoplication and postoperative pH testing for recurrent heartburn: group A--patients with recurrent heartburn and a negative 24-h pH study and group B (control group)--patients with recurrent heartburn and a positive pH study. Questionnaires, a blood sample, and repeat pH testing were completed.

RESULTS

Sixty-nine patients were identified. Group A's depression score (8.6 +/- 4.1) was significantly higher than group B's (5.9 +/- 4.2; P = 0.03). Cytokine levels were similar in both groups. Forty-seven of 49 (96%) patients who underwent repeat pH testing had a negative study. Symptom-reflux correlation was highly significant (P < 0.001).

CONCLUSION

Some patients with recurrent heartburn and a negative pH study have associated functional or psychiatric comorbidities such as depression. Reproducibility of 24-h pH testing in these patients is excellent.

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.

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.

Total fundoplication controls acid and nonacid reflux: evaluation by pre- and postoperative 24-h pH-multichannel intraluminal impedance

BACKGROUND

Studies have demonstrated that Nissen fundoplication controls acid gastroesophageal reflux (GER). Combined 24-h pH and multichannel intraluminal impedance (MII-pH) allows detection of both acid and nonacid GER. Antireflux surgery is considered for any patient whose medical therapy is not efficient, particularly patients with nonacid gastroesophageal reflux disease (GERD). Nevertheless, fundoplication used to control nonacid reflux has not been reported to date.

METHODS

In this study, 15 consecutive patients who underwent laparoscopic Nissen-Rossetti fundoplication had MII-pH both before and after the surgical procedure. The numbers of acid and nonacid GER episodes were calculated with the patient in both upright and recumbent positions.

RESULTS

The 24-h pH monitoring confirmed the postoperative reduction of exposure to acid (p < 0.05). Postoperatively, the total, acid, and nonacid numbers of GER episodes were reduced (p < 0.05).

CONCLUSION

According to the findings, MII-pH is feasible and well tolerated. It provides an objective means for evaluating the effectiveness of Nissen-Rossetti fundoplication in controlling both acid and nonacid GER.

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.

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.

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.

Correlation between gastric pH and gastro-oesophageal reflux contents: ambulatory pH-impedance monitoring results

Gastro-oesophageal reflux events should be related to gastric contents. The goal of this study was to determine the relationship between gastric pH and the nature of reflux events. Ambulatory oesophageal pH-impedance and gastric pH monitoring was performed in 41 patients [29 off and 12 on proton pump inhibitor (PPI) therapy] and 12 controls. The mean gastric pH was measured within 2 min around the reflux episodes, 10 cm below the cardia. Acid reflux events occurred more frequently at gastric pH <4 (89%) than non-acid reflux events (63%, P < 0.0001). Acid reflux events extended more frequently 15 cm above the lower oesophageal sphincter (LOS; 34%) than non-acid reflux episodes (24%, P = 0.005). Gastric pH was significantly lower during interprandial reflux events than during postprandial ones in the three groups (P < 0.001). A positive correlation was found between gastric pH and the nadir oesophageal pH during reflux events in the three groups: this correlation was more significant in patients on PPI therapy. We conclude that most acid and non-acid reflux episodes occur at acid gastric pH, as measured 10 cm below the LOS. This measure does not appear a good predictor of the pH of reflux events.

Role of intra-oesophageal impedance monitoring in the evaluation of endoscopic gastroplication for gastro-oesophageal reflux disease

BACKGROUND

In the evaluation of several endoscopic antireflux procedures, a discrepancy in the degree of improvement between symptoms and objective reflux parameters as measured by pH-metry has been reported.

AIM

To assess the additional value of impedance monitoring in the evaluation of endoscopic gastroplication for gastro-oesophageal reflux disease.

METHODS

Eighteen patients with gastro-oesophageal reflux disease were treated with three endoscopic gastroplications, and underwent 24 h pH-impedance monitoring before and 3 months after treatment.

RESULTS

Total reflux exposure time as assessed by pH-metry and impedance monitoring was significantly decreased after treatment (P = 0.047 and <0.001, respectively). When assessed with impedance monitoring, the mean number of reflux episodes was significantly decreased after the procedure (82 vs. 56, pre vs. post, P < 0.001). Furthermore, the mean numbers of liquid and acid reflux episodes in patients with symptomatic improvement were significantly reduced after treatment (P = 0.04 and 0.02, respectively). After treatment, mean volume clearance time (s) and mean number of proximal reflux episodes were significantly decreased (P < 0.001 and 0.002, respectively).

CONCLUSIONS

Impedance monitoring can identify the specific effect of endoscopic gastroplication on the different types of reflux episodes with regard to gas-liquid composition and pH, as well as on volume clearance and the proximal extent of the refluxate.