Normal 24-hr ambulatory esophageal pH values. Influence of study center, pH electrode, age, and gender

Does helicobacter pylori have a role in the etiology of adenoid hypertrophy?

To investigate whether there is any association between nasopharyngeal reflux and adenoid hypertrophy in children by using 24-h pH monitoring with dual probe and to determine whether Helicobacter pylori simply colonises in adenoid tissue or it is present there temporarily due to extraesophageal reflux. A prospective study at a tertiary referral center. Thirty-two patients who underwent adenoidectomy, aged ranged between 4 and 13 were included. All children with adenoid hypertrophy underwent 24-h pH monitoring with a dual probe. Proximal probe was placed in the nasopharynx. The presence of nasopharyngeal reflux and gastroesophageal reflux were investigated by 24-h pH monitoring. The presence of H. pylori was investigated in adenoidectomy samples by HP-fast test. Of the 32 patients who underwent adenoidectomy, 5 had nasopharyngeal reflux positivity while 27 patients did not show nasopharyngeal reflux positivity with pH monitorisation. Helicobacter pylori could not be detected in 5 nasopharyngeal reflux positive children while 3 of 27 nasopharyngeal reflux negative children showed H. pylori positivity, one of them in the mucosa and others in the core. This study demonstrated the high incidence of nasopharyngeal reflux and gastroesophageal reflux in adenoid hypertrophy and the possible colonisation of H. pylori in the adenoid tissue. This may change the assesment of children with adenotonsillar hypertrophy in near future. However, more placebo controlled and double blind studies and larger series are still needed to support this hypothesis.

Deoxycholic acid causes DNA damage while inducing apoptotic resistance through NF-κB activation in benign Barrett's epithelial cells

Gastroesophageal reflux is associated with adenocarcinoma in Barrett's esophagus, but the incidence of this tumor is rising, despite widespread use of acid-suppressing medications. This suggests that refluxed material other than acid might contribute to carcinogenesis. We looked for potentially carcinogenetic effects of two bile acids, deoxycholic acid (DCA) and ursodeoxycholic acid (UDCA), on Barrett's epithelial cells in vitro and in vivo. We exposed Barrett's (BAR-T) cells to DCA or UDCA and studied the generation of reactive oxygen/nitrogen species (ROS/RNS); expression of phosphorylated H2AX (a marker of DNA damage), phosphorylated IkBα, and phosphorylated p65 (activated NF-κB pathway proteins); and apoptosis. During endoscopy in patients, we took biopsy specimens of Barrett's mucosa before and after esophageal perfusion with DCA or UDCA and assessed DNA damage and NF-κB activation. Exposure to DCA, but not UDCA, resulted in ROS/RNS production, DNA damage, and NF-κB activation but did not increase the rate of apoptosis in BAR-T cells. Pretreatment with N-acetyl-l-cysteine (a ROS scavenger) prevented DNA damage after DCA exposure, and DCA did induce apoptosis in cells treated with NF-κB inhibitors (BAY 11-7085 or AdIκB superrepressor). DNA damage and NF-κB activation were detected in biopsy specimens of Barrett's mucosa taken after esophageal perfusion with DCA, but not UDCA. These data show that, in Barrett's epithelial cells, DCA induces ROS/RNS production, which causes genotoxic injury, and simultaneously induces activation of the NF-κB pathway, which enables cells with DNA damage to resist apoptosis. We have demonstrated molecular mechanisms whereby bile reflux might contribute to carcinogenesis in Barrett's esophagus.

Determination of pH turning point with pH mapping of the gastroesophageal junction: an alternative technique to orientate esophageal pH monitoring

Manometric location of the lower esophageal sphincter (LES) has been mandatory before esophageal pH monitoring, despite costs and discomfort related with esophageal manometry. The aims of the study were: (i) to map the pH of the gastroesophageal junction (GEJ) to determine a pH turning point (PTP) and its relation with LES; and (ii) to test the feasibility of this technique to orientate esophageal pH monitoring. We studied 310 adult patients who underwent esophageal manometry and pH monitoring off acid-suppressive therapy. GEJ pH mapping was carried out by step-pulling the pH sensor from 5 cm below to 5 cm above LES, and a PTP was determined when pH changed from below to above 4, in centimeters from the nostril. Thirty-six patients referred only for pH monitoring were studied with pH sensor placed at 5 cm above the PTP. Out of 310 patients, a PTP was found in 293 (94.5%): inside LES in 86.3%, into the stomach in 8.2% and in the esophageal body in 5.5% of patients. The median distance between PTP and place where pH sensor monitored reflux was 8 cm. Among 36 patients who performed pH monitoring without LES manometry, there was no gastric monitoring during reflux testing. In adult patients investigated off acid suppressive therapy, GEJ pH mapping with reflux monitoring 5 cm above the PTP can be an alternative technique to perform esophageal pH monitoring when LES manometry is not available. Additional studies are needed before the widespread use of GEJ pH mapping in the clinical practice.

NF-κB is activated in oesophageal fibroblasts in response to a paracrine signal generated by acid-exposed primary oesophageal squamous cells

Oesophageal exposure to duodenogastro-oesophageal refluxate leads to reflux oesophagitis and is implicated in the development of Barrett's metaplasia (BM). NF-κB signalling in epithelial cells is associated with the activation of transcription factors believed to be central to BM development, whilst NF-κB activation in fibroblasts plays a critical role in matrix remodelling. Our aim was to study the effects of acid exposure on NF-κB activation in primary human oesophageal fibroblasts (HOFs) and primary and immortalized oesophageal squames and to investigate any epithelial/stromal interactions in the response of these cells to acid. Primary HOFs and primary and immortalized oesophageal epithelial cells were exposed to acid (pH 7 - pH 4 ≤ 120 min) in single or pulsed treatments. Conditioned medium from epithelial cells following acid exposure was also applied to fibroblasts. Cell viability was determined by MTT-ESTA. NF-κB activation was determined by cellular localization of NF-κB/p65 visualized by immunofluorescence. Conditioned medium from oesophageal epithelial cells, subjected to pH 5 pulsatile exposure, activated NF-κB in fibroblasts, with some inter-patient variability, but these conditions did not directly activate NF-κB in the epithelial cells themselves. Significant NF-κB activation was seen in the epithelial cells but only with greater acidity and exposure times (pH 4, 60-120 min). Our findings show that acid exposure can cause indirect activation of stromal cells by epithelial-stromal interactions. This may contribute to the pathogenesis of oesophageal diseases, and the inter-patient variability may go some way to explain why some patients with reflux oesophagitis develop BM and others do not.

Tailored or routine addition of an antireflux fundoplication in laparoscopic large hiatal hernia repair: a comparative cohort study

Background

There is controversy about the tailored or routine addition of an antireflux fundoplication in large hiatal hernia (type II–IV) repair. We investigated the strategy of selective addition of a fundoplication in patients with a large hiatal hernia and concomitant gastroesophageal reflux disease.

Methods

Between 2002 and 2008, 60 patients with a large hiatal hernia were evaluated preoperatively and 12 months after surgery by reflux-related symptoms, upper endoscopy, and esophageal 24-h pH monitoring. In patients with preoperatively documented gastroesophageal reflux disease, an antireflux fundoplication was added during hiatal hernia repair.

Results

An antireflux procedure was added in 35 patients and 25 patients underwent hiatal hernia repair only. Preoperative symptoms were improved or resolved in 31 patients (88.6%) in the group who had fundoplication and in 20 patients (87.0%) in the group who did not have fundoplication. In patients with fundoplication, esophagitis was present in 6 patients (22.2%) after surgery and abnormal esophageal acid exposure persisted in 11 (39.3%). Seven patients (38.9%) with hernia repair only developed abnormal esophageal acid exposure, and esophagitis was postoperatively generated in five (27.8%). In neither group did patients have new onset of daily heartburn or dysphagia.

Conclusions

In patients with a large hiatal hernia associated with gastroesophageal reflux disease, addition of a fundoplication during hernia repair yields acceptable reduction of symptoms and does not generate symptomatic side effects. Objective control of reflux, however, is only moderate. Omission of an antireflux procedure in the absence of gastroesophageal reflux disease induced esophagitis in 28% and abnormal esophageal acid exposure in 39% of patients. Therefore, routine addition of an antireflux fundoplication should be recommended.

Obese patients have stronger peristalsis and increased acid exposure in the esophagus

BACKGROUND

Obesity is a risk factor for GERD and a potential modulator of esophageal motility.

AIM

To assess whether obese patients differ from non-obese patients in terms of esophageal motility and reflux.

METHODS

Patients (n = 332) were categorized in GERD and controls after clinical assessment, esophageal manometry, and pH monitoring. Non-obese (BMI 16-29.9) and obese (BMI 30-68) were compared in regard of distal esophageal amplitude (DEA), LES pressure (LESP), manometric diagnosis, and esophageal acid exposure (EAE).

RESULTS

Obese showed higher DEA in both controls (122 ± 53 vs. 97 ± 36 mmHg, p = 0.041) and GERD patients (109 ± 38 vs. 94 ± 46 mmHg, p < 0.001), higher LESP in GERD patients (20.5 ± 10.6 vs. 18.2 ± 10.6 mmHg, p = 0.049), higher frequency of nutcracker esophagus in controls (30 vs. 0%, p = 0.001), lower frequency of ineffective motility in GERD patients (6 vs. 20%, p = 0.001), and higher EAE in both controls [total EAE: 1.6% (0.7-5.1) vs. 0.9% (0.2-2.4), p = 0.027] and GERD patients [upright EAE: 6.5% (3.8-11.1) vs. 5.2% (1.5-10.6), p = 0.048]. Multiple linear regression showed that BMI was associated either with EAE (p < 0.001), DEA (p = 0.006), or LESP (in men, p = 0.007).

CONCLUSIONS

Obese patients differed from non-obese in terms of esophageal motility and reflux, regardless of the presence of GERD. Obese patients showed stronger peristalsis and increased acid exposure in the esophagus.

Prolonged, wireless pH-studies have a high diagnostic yield in patients with reflux symptoms and negative 24-h catheter-based pH-studies

BACKGROUND

Catheter-based esophageal pH-monitoring is used to evaluate patients with suspected gastro-esophageal reflux disease (GERD); however false-negative results may occur due to poor tolerance of the catheter with reduced oral intake and activity, or high day-to-day variation in reflux and symptom events. We assessed diagnostic yield and clinical impact of prolonged, wireless pH-monitoring in patients with negative results from 24-h catheter-based studies and ongoing symptoms.

METHODS

Esophageal acid exposure (percentage time pH <4), Symptom Index, and Symptom Association Probability (SAP) were calculated. Diagnostic yield was assessed using Average (mean) and Worst Day (24-h period with highest acid exposure or symptom load) analyses. Outcome data were assessed 6-36 months (median 24) after initiation of definitive therapy based on physiologic testing.

KEY RESULTS

Data from prolonged pH-monitoring up to 96-h (median 72-h) were available from 38 patients. Using Average and Worst Day analysis, esophageal acid exposure was pathologic in 37% and 47%, whereas SAP was positive in 34% and 63% of patients, respectively. Overall using Average and Worst Day analyses, 61% and 76% patients were diagnosed with GERD based on either pathologic acid exposure or positive symptom association. Of 12 patients that underwent antireflux surgery, 10(83%) reported a good outcome at a median 24 months follow-up.

CONCLUSIONS & INFERENCES

Prolonged, wireless pH-monitoring increases test sensitivity and diagnostic yield in patients with continuing esophageal symptoms despite negative 24-h catheter-based pH-studies. Without a definitive diagnosis, many would not have received effective treatment.

Impact of symptom-reflux association analysis on long-term outcome after Nissen fundoplication

BACKGROUND

A positive symptom association probability (SAP) is regarded as an important selection criterion for antireflux surgery by many physicians. However, no data corroborate the relationship between symptom-reflux association and outcome, nor is it clear what impact a negative SAP has on the outcome of antireflux surgery in patients with abnormal oesophageal acid exposure. This study compared long-term outcomes of Nissen fundoplication in patients with a negative versus positive SAP.

METHODS

Five-year outcome of Nissen fundoplication in patients with proton-pump inhibitor (PPI)-refractory reflux and pathological acid exposure was compared between those with (SAP+, 109) and without (SAP-, 29 patients) a positive symptom association. Symptoms, quality of life (QoL), PPI use, endoscopic findings, manometry and acid exposure were evaluated.

RESULTS

At 5 years' follow-up, relief of reflux symptoms (95 versus 87 per cent), reduction in PPI use (80 to 25 per cent versus 85 to 14 per cent; P < 0·050) and improvement in QoL were similar in the SAP- and SAP+ groups. Reduction in acid exposure time (13·4 to 1·6 per cent versus 11·1 to 0·2 per cent of total time; P < 0·010), improvement in oesophagitis (44 to 6 per cent versus 61 to 13 per cent; P < 0·050) and increase in lower oesophageal sphincter pressure were also comparable.

CONCLUSION

The subjective and objective outcomes of fundoplication in patients with pathological acid exposure are comparable among those with a positive and negative SAP. Patients with pathological acid exposure and a negative SAP can also benefit from antireflux surgery.

Predictors of objectively identified recurrent reflux after primary Nissen fundoplication

Background

Laparoscopic Nissen fundoplication is the most frequently performed operation for gastro-oesophageal reflux disease (GORD). Studies on predictors of subjective outcome of fundoplication have yielded inconsistent results. This study identified predictors of objective reflux control after Nissen fundoplication.

Methods

This was a retrospective analysis of prospectively collected data from patients who underwent Nissen fundoplication for proton pump inhibitor-refractory GORD with pathological acid exposure in a single centre between 1997 and 2005. The predictive value of demographics, endoscopic hiatal hernia size, oesophagitis, lower oesophageal sphincter pressure, distal oesophageal contraction amplitude, percentage of peristaltic contractions and acid exposure was determined. Endpoints were recurrent pathological acid exposure on 24-h pH monitoring at 6 months and surgical reintervention for recurrent GORD up to 6 years.

Results

Of 177 patients, 22 had recurrent pathological acid exposure at 6 months for which 11 had surgery within 6 years. Only low percentage of peristaltic contractions (odds ratio (OR) 0·97, 95 per cent confidence interval 0·95 to 0·99; P = 0·004) and high supine acid exposure (OR 1·03, 1·00 to 1·07; P = 0·025) were independent predictors of recurrent pathological acid exposure. The absolute risk of recurrent exposure was 45·5 per cent in patients with both predictors. High supine acid exposure was also an independent predictor of surgical reintervention (OR 1·05, 1·01 to 1·08; P = 0·006).

Conclusion

Nissen fundoplication should not necessarily be withheld from patients with poor oesophageal peristalsis or excessive supine acid exposure. As about half of patients with both variables experience recurrent pathological acid exposure after primary Nissen fundoplication, surgery should be restricted in this group.

Inhibitory effect of rosiglitazone on the acid-induced intracellular generation of hydrogen peroxide in cultured feline esophageal epithelial cells

Peroxisome proliferator-activated receptor-gamma (PPARγ) agonists have been reported to enhance antioxidant defenses by increasing levels of catalase and copper-zinc superoxide dismutase (Cu/Zn SOD) in oligodendrocyte progenitor cells. In this study, we investigated the effects of the PPARγ agonist, rosiglitazone, on hydrogen peroxide (H(2)O(2)) generation by acidified medium at pH 5.5 (AM5.5), which is in the pH range of duodenogastric refluxates, in primary cultured feline esophageal epithelial cells (EEC). Successful isolation of EEC was identified by immunocytochemistry. AM5.5- and rosiglitazone-induced cell viabilities were determined using 3-(4,5-dimethylthiozol-2-yl)-2,5-diphenyltetrazolium bromide assays. The NAD(P)H oxidase activity was measured, and expression of catalase or SOD protein by AM5.5 in the absence and presence of rosiglitazone was assessed using western blotting analysis. PPARγ protein and mRNA were constitutively expressed in EEC. In the incubation with rosiglitazone alone, cell viability was shown more than 90% at 0-10 μM for 72 h. After exposure to AM5.5 for 8 h, intracellular H(2)O(2) was significantly generated. Treatment with rosiglitazone prior to and during exposure to AM5.5 inhibited the H(2)O(2) generation whereas the specific PPARγ antagonist GW9662 offsets the inhibitory action of rosiglitazone. H(2)O(2) generation was also prevented by a nonspecific ROS scavenger N-acetylcysteine or an inhibitor of NADPH oxidase diphenyleneiodonium. The enhanced AM5.5-induced NAD(P)H oxidase activity was not suppressed by rosiglitazone. Instead, the pretreatment of rosiglitazone enhanced the protein expression of catalase, Cu/Zn SOD, and Mn SOD, which are endogenous antioxidative enzymes. These findings indicate that rosiglitazone inhibits AM5.5-induced intracellular H(2)O(2) production, which occurs via NAD(P)H oxidase activation, by using a PPARγ-dependent pathway, and that the underlying mechanism involves an increase in the expression of catalase and SOD proteins.

Laboratory based investigations for diagnosing gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) still remains the most common out- GI-related condition in the out-patient setting. While primary care physicians often use empiric trials with proton pump inhibitors (PPI trial) to diagnose GERD, often specialised tests are required to confirm or exclude gastroesophageal reflux causing esophageal or extraesophageal symptoms. The most commonly used procedures to diagnose GERD include: conventional (catheter based) pH monitoring, wireless esophageal pH monitoring (Bravo), bilirubin monitoring (Bilitec), and combined multichannel intraluminal impedance-pH monitoring (MII-pH). Each technique has strengths and limitations of which clinicians and investigators should be aware when deciding which one to choose.

Reflux episodes are similar in healthy African Americans and non-Hispanic whites

Ambulatory esophageal pH monitoring is the current gold standard diagnostic exam for gastroesphageal reflux disease. Presently, no data are available for normal 24-hour esophageal pH monitoring among any US ethnic group. The aim of the present study was to obtain normal values of 24-hour esophageal pH monitoring in healthy adult African American (AA) volunteers and compare these with values obtained in healthy non-Hispanic white (nHw) volunteers to determine if ethnic variation exists in 24-hour esophageal pH testing. Twenty-four-hour dual esophageal pH monitoring was performed in healthy AA and nHw. Values for total number of reflux episodes, episodes longer than 5 min, total reflux time in minutes, and longest reflux episode in the proximal and distal esophagus were obtained for both ethnic groups. Differences between groups were considered significant if P < 0.05. Eighty subjects volunteered for the study and completed 24-hour pH testing. Forty-one were AAs and 39 were nHws, with males making up 49% of each group. The AAs were older and had higher body mass index than the nHws. No difference was observed between the AA and the nHw subjects for any measured pH parameter in either the proximal or distal esophagus. There is no difference in values obtained during esophageal pH monitoring in healthy African Americans and non-Hispanic whites. This indicates that the currently accepted normal values of ambulatory esophageal pH monitoring are readily applicable to African Americans and can be used without compromising diagnostic accuracy in this ethnic group.

Altered sensorimotor responses to esophageal acidification in older adults with GERD

OBJECTIVE

This study aimed to compare the effect of intraluminal acidification on esophageal sensory perception and motor activity between older and younger patients with gastroesophageal reflux disease (GERD).

MATERIAL AND METHODS

All 40 subjects had saline and hydrochloric acid infused into the mid-esophagus. The esophageal perception to acid infusion was documented including lag time, intensity rating, and sensitivity score. Esophageal body motility was recorded.

RESULTS

The younger group had a shorter lag time to initial heartburn perception (p = 0.01) and a greater sensory intensity rating (p = 0.001). The acid infusion sensitivity score was lower in the older patients (p = 0.001). Age positively correlated to lag time to initial symptom perception (r = 0.44, p = 0.005), but negatively correlated to sensory intensity (r = -0.40, p = 0.01) and acid infusion sensitivity score (r = -0.39, p = 0.01). When compared with saline infusion, acid infusion induced a significant increase in the deglutition frequency in younger patients (0.51 vs. 0.67, p = 0.005), but not in older patients (0.59 vs. 0.65, p = 0.67).

CONCLUSIONS

Age-related decrease in sensorimotor response to esophageal acidification may be an important element in the pathogenesis and clinical presentation of GERD in older adults.

Symptomatic and objective results of laparoscopic Nissen fundoplication after failed EndoCinch gastroplication for gastro-oesophageal reflux disease

BACKGROUND

Several endoscopic techniques have been introduced to treat gastro-oesophageal reflux disease, but their effectiveness varies. Subsequent laparoscopic Nissen fundoplication (LNF) might be required because of persistence or recurrence of symptoms. The aim of this study was to evaluate the outcome of LNF after previous EndoCinch gastroplication.

METHODS

Eleven consecutive patients who underwent LNF after failed EndoCinch were included. Data were prospectively collected. Symptomatic outcome was obtained by validated questionnaires, and objective outcome by endoscopy, oesophageal manometry and pH monitoring.

RESULTS

LNF was performed without major complications. After a median (range) follow-up of 31 (6-61) months, preoperative symptoms were resolved or improved in nine patients (81.8%), and general quality of life was significantly improved. None of the patients experienced daily complaints of heartburn postoperatively, and the median Gastro-Esophageal Reflux Disease Health Related Quality of Life score was 4 (0-9). Three patients (27.3%) had troublesome daily dysphagia. Oesophageal acid exposure was normalised after surgery in all but one patient, and another patient (9.1%) had persisting grade A oesophagitis. One patient (9.1%) underwent revisional LNF because of reflux and dysphagia caused by an intrathoracic migrated wrap.

CONCLUSION

This study has shown that quality of life and reflux control were satisfactory after LNF for failed EndoCinch gastroplication. Troublesome dysphagia was more frequently present after surgery in comparison with primary LNF.

Acid and bile salt-induced CDX2 expression differs in esophageal squamous cells from patients with and without Barrett's esophagus

BACKGROUND & AIMS

It is not clear why only a minority of patients with gastroesophageal reflux disease (GERD) develop Barrett's esophagus. We hypothesized that differences among individuals in molecular pathways activated when esophageal squamous epithelium is exposed to reflux underlie the development of Barrett's metaplasia.

METHODS

We used esophageal squamous cell lines from patients who had GERD with Barrett's esophagus (normal esophageal squamous [NES]-B3T and NES-B10T) and without Barrett's esophagus (NES-G2T and NES-G4T) to study effects of acid and bile salts on expression of the CDX2 gene. Bay 11-705, Ad5 inhibitor kappaB(IkappaB)alpha-SR, and site-directed mutagenesis were used to explore effects of nuclear factor-kappaB (NF-kappaB) inhibition on CDX2 promoter activity; DNA binding of the NF-kappaB subunits p50 and p65 was assessed by chromatin immune-precipitation.

RESULTS

Acid and bile salts increased CDX2 messenger RNA (mRNA), protein, and promoter activity in NES-B3T and NES-B10T cells, but not in NES-G2T or NES-G4T cells. Inhibition of NF-kappaB abolished the increase in CDX2 promoter activity. Increased CDX2 promoter activity was associated with nuclear translocation of p50, which bound to the promoter. We found CDX2 mRNA in 7 of 10 esophageal squamous biopsy specimens from patients with Barrett's esophagus, but in only 1 of 10 such specimens from patients who had GERD without Barrett's esophagus.

CONCLUSIONS

Acid and bile salts induce CDX2 mRNA and protein expression in esophageal squamous cells from patients with Barrett's esophagus, but not from GERD patients without Barrett's esophagus. We speculate that these differences in acid- and bile salt-induced activation of molecular pathways may underlie the development of Barrett's metaplasia.

Long-term outcome of Nissen fundoplication in non-erosive and erosive gastro-oesophageal reflux disease

BACKGROUND

Non-erosive (NERD) and erosive (ERD) gastro-oesophageal reflux disease (GORD) show similar severity of symptoms and impact on quality of life (QoL). Prospective data on long-term outcomes of antireflux surgery in NERD are lacking.

METHODS

Subjective and objective 5-year outcomes of Nissen fundoplication were compared in 96 patients with NERD and 117 with ERD, operated on for proton-pump inhibitor (PPI)-refractory GORD.

RESULTS

Preoperative and postoperative QoL, PPI use, acid exposure time, symptom-reflux correlation, lower oesophageal sphincter (LOS) pressure and reoperation rates were similar in the two groups. At 5 years, relief of reflux symptoms was similar (NERD 89 per cent versus ERD 96 per cent), PPI use showed a similar reduction (82 to 21 per cent versus 81 to 15 per cent respectively; both P < 0.001) and QoL score improved equally (50.3 to 65.2 (P < 0.001) versus 52.0 to 60.7 (P = 0.016)). Five patients with NERD developed erosions after surgery; oesophagitis healed in 87 per cent of patients with ERD. Reduction in total acid exposure time (NERD 12.7 to 2.0 per cent versus ERD 13.8 to 2.9 per cent; both P < 0.001) and increase in LOS pressure (1.3 to 1.8 kPa versus 1.2 to 1.8 kPa; both P < 0.001) were similar. The reintervention rate was comparable (NERD 15 per cent versus ERD 12.8 per cent).

CONCLUSION

Patients with PPI-refractory NERD and ERD benefit equally from Nissen fundoplication. The absence of mucosal lesions on endoscopy in patients with proven PPI-refractory reflux disease is not a reason to refrain from antireflux surgery.

How to Interpret Ambulatory 24 hr Esophageal pH Monitoring

Newer developing techniques for esophageal functional testing such as wireless pH capsule monitoring and esophageal impedance testing are currently available. However, ambulatory 24 hr esophageal pH monitoring is still widely used and provides quantitative data on esophageal acid exposure and the ability to correlate symptoms with acid exposure events. To properly analyze the result of pH monitoring, it is recommended to interpret in the order presented: visual inspection, computer calculation and symptom correlation.

Acid and bile salt up-regulate BMP4 expression in human esophageal epithelium cells

OBJECTIVE

Barrett's esophagus (BE) with an intestinal-type epithelium is thought to be a precancerous lesion of adenocarcinoma of the esophagus. The pathophysiology of Barrett's metaplasia is poorly understood. Previous studies suggest that differentiation of multipotent cells to columnar epithelium may be one of the possible mechanisms. Bone morphogenetic protein 4 (BMP4), a factor determining the fate of cells, is up-regulated in BE and esophagitis mucosa when compared with normal squamous or non-goblet cell-containing cardiac epithelium. The aim of this study was to demonstrate that BMP4 is a molecular mediator that links etiological agents of BE to the phenotypic changes in human esophagus epithelium cells (HEECs).

MATERIAL AND METHODS

Primary cultured HEECs were used to investigate the effect of acid and bile salt on BMP4 expression and to examine the biological effects of BMP4 on HEECs.

RESULTS

Acid and bile salt increased the expression of BMP4. In addition, recombinant human BMP4 induced villin expression in HEECs, as did chronic acid exposure, which can be effectively inhibited by Noggin, a specific antagonist of BMP4. Results from a Western blot assay suggest that BMP4 induces activation of smad1 and promotes protein expression of ID2 and CDX2.

CONCLUSION

BMP4 may play an important role in the development of BE.

Lack of correlation between a self-administered subjective GERD questionnaire and pathologic GERD diagnosed by 24-h esophageal pH monitoring

INTRODUCTION

Self-reported reflux symptoms do not always correspond to pathologic gastroesophageal reflux disease (GERD). We evaluated whether GERD-related symptoms in the self-reported Mayo-GERD questionnaire (GERDQ) were correlated with current gold standard definitions of pathologic GERD.

METHODS

Three hundred thirty-six consecutive consenting individuals with GERD symptoms referred for 24-h esophageal pH monitoring completed a baseline GERDQ. Univariate and multivariate analyses identified questions that were most associated with percent total time pH<4 at distal probe (DT) >4% or DeMeester score (DS) >or=14.7, two accepted definitions of pathologic GERD. A risk score was created from these analyses, followed by generation of receiver operating characteristic curves and determination of C-statistics, sensitivity, and specificities at various cut points, with prespecified minimal values of each that would be required to meet the definition of "potential clinical utility."

RESULTS

Forty-nine percent of patients were found to have pathologic GERD; half the patients (not necessarily those with pathologic GERD) described suffering from severe or very severe heartburn or acid regurgitation in the past year. Univariate logistic regression analysis identified six of 22 key GERD questions that were significantly related to DT or DS, in addition to age and gender. Three questions (duration of symptoms, nocturnal heartburn, hiatal hernia) along with age and gender remained significant in multivariate analyses. A risk score (RS) was created from these five questions separately for DT and DS. For DT, the C-statistic for RS was 0.75, and at the optimal cut point of >or=6 that maximizes sensitivity (SS) and specificity (SP), SS was 68% and SP was 72%. For DS, the C-statistic was 0.73, and at the optimal cut point, SS was 82%and SP 60%. When considering other cut points, the rare extreme case of very low RS (<or=2) was strongly predictive of lack of pathologic GERD: for DT, SS 100%/SP 18%, negative predictive value (NPV) 100%; and for DS, SS 97%, SP 25%, NPV 88%. However, only 10-15% of patients referred for pH testing had RS scores of <or=2.

CONCLUSION

Self-reported prolonged history of GERD-like symptoms, nocturnal heartburn, history of a hiatus hernia, and male gender were associated with abnormal 24-h esophageal pH monitoring. However, these factors lack clinical utility to predict pathologic GERD in patients referred for pH testing. We found that 51% of patients with severe GERD symptoms do not have true pathological GERD on objective testing. The clinical implications of this study are significant in that treatment with acid-suppressing medication in such patients would be inappropriate.

Review article: sleep-related gastro-oesophageal reflux as a distinct clinical entity

BACKGROUND

Many patients with chronic gastro-oesophageal reflux disease (GERD) have frequent nighttime heartburn as well as sleep-related gastro-oesophageal reflux (GOR). Sleep-related GOR has been shown to play an important role in the development of oesophagitis and other complications of GOR.

AIM

To present a conceptual argument that nighttime heartburn and associated sleep-related GOR should be recognized as a distinct clinical entity deserving special attention with regard to the diagnosis and treatment of GERD.

METHODS

The data presented come from surveys of GERD patients as well as from physiological studies to include studies monitoring oesophageal pH and spontaneous reflux events during polysomnographically (PSG) monitored sleep.

RESULTS

Evidence is presented to show that nighttime heartburn is prevalent and its occurrence separates patients from those who have heartburn most exclusively in the daytime. The evidence presented also supports the notion that nighttime heartburn sufferers have a more complicated disease and they have a greater risk of developing oesophagitis and other respiratory complications. The data also show that responses to acid mucosal contact are quite different during sleep compared to responses measured during the waking state.

CONCLUSIONS

Nighttime heartburn and GOR represent a distinct clinical entity which deserves specific attention in the diagnosis and optimal treatment of GERD.

Ten-year outcome of laparoscopic and conventional nissen fundoplication: randomized clinical trial

OBJECTIVE

To compare 10 years outcome of a multicenter randomized controlled trial on laparoscopic (LNF) and conventional Nissen fundoplication (CNF), with focus on effectiveness and reoperation rate.

SUMMARY OF BACKGROUND DATA

LNF has replaced CNF as surgical treatment for gastroesophageal reflux disease (GERD). Decisions are based on equal short-term effectiveness and reduced morbidity, but confirmation by long-term level 1 evidence is lacking.

METHODS

From 1997 to 1999, 177 proton pump inhibitor (PPI)-refractory GERD patients were randomized to undergo LNF or CNF. The 10 years results of surgery on reflux symptoms, general health, PPI use, and reoperation rates, are described. High-resolution manometry, 24-hour pH-impedance monitoring and barium swallow were performed in symptomatic patients only.

RESULTS

A total of 148 patients (79 LNF, 69 CNF) participated in this 10-year follow-up study. GERD symptoms were relieved in 92.4% and 90.7% (NS) after LNF and CNF, respectively. Severity of heartburn and dysphagia were similar, but slightly more patients had relief of regurgitation after LNF (98.7% vs. 91.0%; P = 0.030). The percentage of patients using PPIs slowly increased with time in both groups to 26.6% for LNF and 22.4% for CNF (NS). General health (74.7% vs. 72.7%; NS) and quality of life (visual analogue scale score: 65.3 vs. 61.4; NS) improved similarly in both groups. The percentage of patients who would have opted for surgery again was similar as well (78.5% vs. 72.7%; NS). Twice as many patients underwent reoperation after CNF compared with LNF (12 [15.2%] vs. 24 [34.8%]; P = 0.006), including a higher number of incisional hernia corrections (2 vs. 9; P = 0.015). Mean interval between operation and reintervention was longer after CNF (22.9 vs. 50.6 months; P = 0.047). Of the patients who were dependent on daily PPI therapy at 10 years (LNF 10, CNF 10), 7 patients (LNF 3, CNF 4) had recurrent GERD on pH-impedance monitoring, 5 of them with some form of anatomic recurrence. A total of 13 of 20 (65.0%) patients did not have recurrent GERD. Fourteen patients had an abnormal high-resolution manometry.

CONCLUSIONS

CNF carries a higher risk for surgical reintervention compared with LNF, mainly due to incisional hernia corrections. The 10-year effectiveness of LNF and CNF is comparable in terms of improvement of GERD symptoms, PPI use, quality of life, and objective reflux control. Consequently, the long-term results from this trial lend level 1 support to the use of LNF as the surgical procedure of choice for GERD.

The modern investigation and management of gastro-oesophageal reflux disease (GORD)

Gastro-oesophageal reflux disease results from impaired function of the LOS and acid clearance of the distal oesophagus. Most patients do not require investigation and respond either to lifestyle changes, antacid/alginates, H2A, PPI or a combination of these treatments. Surgery is only rarely indicated.

Manometric findings in patients with isolated distal gastroesophageal reflux

AIM: To analyze manometric abnormalities in patients with isolated distal reflux and compare these findings in patients with erosive and non-erosive disease.

METHODS: Five hundred and fifty patients who presented to the outpatient clinic of Turkiye Yuksek Ihtisas Hospital with gastroesophageal reflux disease-like symptoms were enrolled. Each individual was evaluated with esophageal manometry, 24-h ambulatory pH monitoring, and upper gastrointestinal endoscopy. Manometric findings for the patients with isolated distal reflux were compared to findings in controls who were free of reflux disorders or hypersensitive esophagus. Findings for isolated distal reflux patients with and without erosive reflux disease were also compared.

RESULTS: Of the 550 subjects enrolled, 97 (17.6%, mean age 48 years) had isolated distal reflux and 100 had no abnormalities on ambulatory pH monitoring (control group, mean age 45 years). There were no significant differences between the isolated distal reflux group and control group with respect to age, body mass index, and esophageal body contraction amplitude (EBCA). Mean lower esophageal sphincter pressure was significantly higher in the control group (12.7 ± 10.3 mmHg vs 9.6 ± 7.4 mmHg, P = 0.01). Fifty-five (56.7%) of the 97 patients with isolated distal reflux had erosive reflux disease. There were no statistical differences between the erosive reflux disease and non-erosive reflux disease subgroups with respect to mean EBCA, lower esophageal sphincter pressure, or DeMeester score. However, 13% of patients with gastroesophageal reflux disease had distal wave amplitudes ≤ 30 mmHg, whereas none of the patients with non-erosive reflux disease had distal wave amplitudes in this low category.

CONCLUSION: Patients with erosive and non-erosive disease present with similar manometric abnormalities. The only striking difference is the observation of very low EBCA exclusively in patients with erosive disease.

In benign Barrett's epithelial cells, acid exposure generates reactive oxygen species that cause DNA double-strand breaks

Cells that sustain double-strand breaks (DSB) can develop genomic instability, which contributes to carcinogenesis, and agents that cause DSBs are considered potential carcinogens. We looked for evidence of acid-induced DNA damage, including DSBs, in benign Barrett's epithelial (BAR-T) cell lines in vitro and in patients with Barrett's esophagus in vivo. In BAR-T cells, we also explored the mechanisms underlying acid-induced DNA damage. We exposed BAR-T cells to acid in the presence of a fluorescent probe for reactive oxygen species (ROS) and in the presence or absence of disodium 4,4'-diisothiocyanatostilbene-2,2'-disulfonate (which prevents intracellular acidification) and N-acety-l-cysteine (a scavenger of ROS). DSBs were detected by Western blotting and immunofluorescence for histone H2AX phosphorylation and by CometAssay. During endoscopy in patients with Barrett's esophagus, we took biopsy specimens from the metaplastic mucosa before and after esophageal perfusion with 0.1 N HCl for 3 min and sought DSBs by Western blotting for histone H2AX phosphorylation. In BAR-T cells, acid exposure resulted in ROS production and caused a time-dependent increase in levels of phospho-H2AX that continued for at least 48 h. Pretreatment with disodium 4,4'-diisothiocyanatostilbene-2,2'-disulfonate or N-acety-l-cysteine prevented the acid-induced increase in phospho-H2AX levels. DSBs also were detected in biopsy specimens of Barrett's metaplasia following esophageal acid perfusion in all of 6 patients with Barrett's esophagus. Acid exposure causes DSBs in Barrett's epithelial cells through ROS produced as a consequence of intracellular acidification. These findings suggest that acid can be considered a carcinogen in Barrett's esophagus.

Gastroesophageal reflux might cause esophagitis through a cytokine-mediated mechanism rather than caustic acid injury

BACKGROUND & AIMS

Reflux esophagitis is believed to be caused by the caustic effects of refluxed gastric acid on esophageal epithelial cells. However, caustic chemical injuries develop rapidly whereas esophagitis might not appear until weeks after the induction of reflux in animal models. We studied early histologic events in the development of reflux esophagitis in a rat model and performed in vitro experiments to determine whether exposure to acidified bile salts causes esophageal epithelial cells to secrete chemokines that might contribute to inflammation.

METHODS

At various time points after esophagoduodenostomy, the rat esophagus was removed and inflammatory changes were analyzed by histologic analyses. Human esophageal squamous cell lines were exposed to acidified bile salts to evaluate their effects on cytokine production and immune-cell migration.

RESULTS

Reflux esophagitis started at postoperative day 3 with lymphocytic infiltration of the submucosa that progressed to the epithelial surface-these findings contradicted those expected from a caustic chemical injury. Basal cell and papillary hyperplasia preceded the development of surface erosions. Exposure of squamous cells to acidified bile salts significantly increased the secretion of interleukin-8 and interleukin-1beta; conditioned media from these cells caused significant increases in the migration rates of T cells and neutrophils.

CONCLUSIONS

These findings support, but do not prove, an alternative concept for the development of reflux esophagitis in which refluxed gastric juice does not directly damage the esophagus, but rather stimulates esophageal epithelial cells to secrete chemokines that mediate damage of esophageal tissue.

Gastroesophageal reflux in mechanically ventilated pediatric patients and its relation to ventilator-associated pneumonia

INTRODUCTION

The objective was to determine the frequency of gastroesophageal reflux (GER) in mechanically ventilated pediatric patients and its role as a risk factor for ventilator-associated pneumonia (VAP), which may be enhanced among those patients.

METHODS

The study is a prospective cohort study of mechanically ventilated pediatric patients in the pediatric intensive care unit (PICU) of Ain Shams University Children's Hospital. It was conducted in 24 mechanically ventilated patients (16 of them developed VAP and 8 did not, with mean age of 16.6 +/- 20.5 and 18.6 +/- 22.4 months respectively). Esophageal 24-hour pH-metry beside clinical and laboratory evaluation of their underlying problem and severity of their condition were carried out.

RESULTS

All VAP patients had GER (50% alkaline reflux, 12.5% acidic reflux and 37.5% combined reflux) compared to 75% of non-VAP ones (100% alkaline reflux). The mean total reflux time was significantly longer among VAP (50 minutes) versus non-VAP (3 minutes) patients. There was significant increase in acidic reflux parameters among non-survivors versus survivors (P < 0.001). For VAP mortality, total acidic reflux at a cut-off value of 28.6 minutes is found to be a mortality predictor with a sensitivity of 100% and a specificity of 100%.

CONCLUSIONS

GER is a constant incident in mechanically ventilated pediatric patients, with alkaline reflux being more common than acidic reflux. Both acidic and alkaline refluxes were found to be associated with the development of VAP and total reflux time was found to be a reliable predictor of VAP. Moreover, acidic reflux was found to be more related to mortality than alkaline reflux.

Functional evaluation at 1-year follow-up of laparoscopic Nissen-Rossetti fundoplication

Laparoscopic Nissen fundoplication is currently the gold standard for surgical treatment of gastroesophageal reflux disease. The aim of this study was to present our experience with this procedure at 1 year of follow-up. Forty patients were operated on between January 2006 and July 2007, and 30 underwent a 24-hour postoperative pH-metry study. Ninety-two percent of the patients were asymptomatic at a follow-up of 12 months. All pH-metric parameters improved. DeMeester and Johnson's score was reduced from 44.7 to 7.75; endoscopy with histologic samples revealed the healing of esophagitis in all patients; 4 (13%) patients complained of dysphagia, which resolved within 1 month after surgery. Twenty-seven (90%) patients were completely satisfied by their surgical results. One year after surgery, 24-hour ph-metric results show that laparoscopic Nissen fundoplication can completely control acid reflux with relatively few complications and a high degree of patient satisfaction.

Oesophageal acid hypersensitivity is not a contraindication to Nissen fundoplication

BACKGROUND

The Rome III criteria classify patients with a positive relationship between symptoms and reflux episodes but a physiological oesophageal acid exposure time as having gastro-oesophageal reflux disease (GORD) with an acid hypersensitive oesophagus. The long-term outcome of antireflux surgery in these patients was investigated.

METHODS

Outcomes of Nissen fundoplication in 28 patients with GORD refractory to proton-pump inhibitors (PPIs) and oesophageal acid hypersensitivity (group 1) were compared with those of 126 patients with pathological acid exposure (group 2).

RESULTS

Fundoplication had a similar effect in both groups. Three months after surgery, total acid exposure time and the prevalence of oesophagitis had decreased, whereas mean lower oesophageal pressure had increased. The percentage of patients using PPIs was reduced from 83 to 4 per cent in group 1 and from 86.1 to 7.4 per cent in group 2 (both P < 0.001). Quality of life measured on a scale from 0 to 100 improved from 52 to 69 (P = 0.009) and 64 (P < 0.001) respectively. The percentage of patients with resolved or improved symptoms at 5 years was similar.

CONCLUSION

Patients with oesophageal acid hypersensitivity benefit from Nissen fundoplication as much as those with pathological acid exposure.

A new pH catheter for laryngopharyngeal reflux: Normal values

OBJECTIVES/HYPOTHESIS

Laryngopharyngeal reflux (LPR) represents a challenging field. Therapeutic studies of proton pump inhibitors in LPR have shown mixed results. The Restech pH catheter (Respiratory Technology Corp., San Diego, CA) is a minimally invasive device for detection of oropharyngeal acid reflux. The aim of this study was to provide normative data using this device in both distal esophagus and oropharynx.

STUDY DESIGN

Prospective observational study.

METHODS

Normal volunteers were recruited to undergo pH monitoring. A custom made longer catheter was used to assess distal esophageal pH. Oropharyngeal pH catheter was placed at the level of uvula. The distribution of % time was summarized using the 5th, 25th, 50th (median), 75th, and 95th quantiles for pH < 6, pH < 5, and pH < 4 for both upright and supine positions.

RESULTS

A total of 20 normal, healthy volunteers underwent pH monitoring for 14 to 24 hours (median 20.5 hours). The 95th percentile for % total time pH < 4, pH < 5, pH < 6 for the distal esophageal pH catheter were 4.52%, 10.91%, and 42.99%, respectively. For the oropharynx pH probe, the 95th percentile for % total time pH < 4, pH < 5, and pH < 6 were 0.02%, 2.33%, and 21.41% respectively. The 95th percentile for number of reflux events for total pH < 4, pH < 5, and pH < 6 were 1.3, 8.1, and 128.0, respectively.

CONCLUSIONS

Oropharyngeal acid reflux is an infrequent occurrence in healthy volunteers without LPR. The normative data for Restech pH catheter may now be compared to those with suspected LPR.

Effects of asymptomatic proximal and distal gastroesophageal reflux on asthma severity

RATIONALE

Silent gastroesophageal reflux (GER) is common in patients with asthma, but it is unclear whether GER is associated with worse asthma symptoms or reduced lung function.

OBJECTIVES

To determine in patients with poorly controlled asthma, whether proximal or distal esophageal reflux is associated with asthma severity, symptoms, physiology, or functional status.

METHODS

Baseline asthma characteristics were measured in patients with asthma enrolled in a multicenter trial assessing the effectiveness of esomeprazole on asthma control. All participants underwent 24-hour esophageal pH probe monitoring. Lung function, methacholine responsiveness, asthma symptoms, and quality-of-life scores were compared in subjects with and without GER.

MEASUREMENTS AND MAIN RESULTS

Of 304 participants with probe recordings, 53% had reflux. Of 242 participants with recordings of proximal pH, 38% had proximal reflux. There was no difference in need for short-acting bronchodilators, nocturnal awakenings, dose of inhaled corticosteroid, use of long-acting beta-agonists, lung function, or methacholine reactivity between individuals with and without proximal or distal GER. Participants with GER reported more use of oral corticosteroids and had worse asthma quality of life and subjects with proximal GER had significantly worse asthma quality of life and health-related quality of life compared with participants without GER.

CONCLUSIONS

Asymptomatic GER is not associated with distinguishing asthma symptoms or lower lung function in individuals with suboptimal asthma control who are using inhaled corticosteroids. Patients with proximal reflux report significantly worse asthma and health-related quality of life despite lack of physiologic impairment or increase in asthma symptoms. Clinical trial registered with www.clinicaltrials.gov (NCT00069823).

The preoperative reflux pattern as prognostic indicator for long-term outcome after Nissen fundoplication

OBJECTIVES

We set out to investigate the impact of the preoperative reflux pattern on long-term outcome after Nissen fundoplication. Recent studies disagree on whether patients with pathological upright reflux should be discouraged from undergoing surgery.

METHODS

A total of 338 patients underwent Nissen fundoplication. Of these, 234 of 289 patients had pathological acid exposure on preoperative 24-h esophageal pH monitoring and their reflux was classified as pathological upright (n=81), supine (n=55), or bipositional (n=98). Clinical outcomes and results of endoscopy, manometry, and 24-h pH monitoring were compared before surgery, and at 3 months and 5 years after surgery.

RESULTS

Patients with pathological upright and supine reflux had similar preoperative reflux parameters. In patients with pathological bipositional reflux, however, preoperative total acid exposure was higher than that in patients with upright or supine reflux (18.3% vs. 10.7 and 7.5%; P<0.001 and P<0.001). Prevalence of esophagitis was higher in patients with bipositional reflux than in those with upright reflux, both before (64.0 vs. 45.6%; P=0.035) and 3 months after surgery (16.0 vs. 3.5%; P=0.018). Before surgery, mean lower esophageal sphincter (LES) pressure was lower compared with the upright and supine reflux groups (1.0 vs. 1.5 and 1.6 kPa; P=0.007 and 0.005, respectively). The increase in quality of life, reduction of symptoms, use of acid-suppressing drugs, total acid exposure, and esophagitis were independent of reflux pattern at 3 months and 5 years after surgery (all P<0.05). Prevalence of recurrent pathological acid exposure was higher in the bipositional group than in the upright group (40.9 vs. 10.7%; P=0.013). Surgical reintervention was significantly more common in bipositional reflux patients (20.0 vs. 8.9% for upright and 4.1% for supine).

CONCLUSIONS

All three pathological reflux patterns respond favorably to Nissen fundoplication in the long term. Patients with pathological bipositional reflux, however, suffer from more severe disease with higher chance of recurrence and reoperation.

Efficacy of esomeprazole for treatment of poorly controlled asthma

BACKGROUND

Gastroesophageal reflux is common among patients with asthma but often causes mild or no symptoms. It is not known whether treatment of gastroesophageal reflux with proton-pump inhibitors in patients who have poorly controlled asthma without symptoms of gastroesophageal reflux can substantially improve asthma control.

METHODS

In a parallel-group, double-blind trial, we randomly assigned 412 participants with inadequately controlled asthma, despite treatment with inhaled corticosteroids, and with minimal or no symptoms of gastroesophageal reflux to receive either 40 mg of esomeprazole twice a day or matching placebo. Participants were followed for 24 weeks with the use of daily asthma diaries, spirometry performed once every 4 weeks, and questionnaires that asked about asthma symptoms. We used ambulatory pH monitoring to ascertain the presence or absence of gastroesophageal reflux in the participants. The primary outcome was the rate of episodes of poor asthma control, as assessed on the basis of entries in asthma diaries.

RESULTS

Episodes of poor asthma control occurred with similar frequency in the placebo and esomeprazole groups (2.3 and 2.5 events per person-year, respectively; P=0.66). There was no treatment effect with respect to individual components of the episodes of poor asthma control or with respect to secondary outcomes, including pulmonary function, airway reactivity, asthma control, symptom scores, nocturnal awakening, or quality of life. The presence of gastroesophageal reflux, which was documented by pH monitoring in 40% of participants with minimal or no symptoms, did not identify a subgroup of patients that benefited from treatment with proton-pump inhibitors. There were fewer serious adverse events among patients receiving esomeprazole than among those receiving placebo (11 vs. 17).

CONCLUSIONS

Despite a high prevalence of asymptomatic gastroesophageal reflux among patients with poorly controlled asthma, treatment with proton-pump inhibitors does not improve asthma control. Asymptomatic gastroesophageal reflux is not a likely cause of poorly controlled asthma. (ClinicalTrials.gov number, NCT00069823.)

Continuous distal oesophageal acidification decreases postprandial gastric acidity in healthy human subjects

BACKGROUND

Previously, we hypothesized that exposing the distal oesophagus to acid signals the stomach to decrease gastric acidity.

AIM

To test the hypothesis that exposing the distal oesophagus to acid signals the stomach to decrease gastric acidity.

METHODS

Twenty-two healthy humans ingested a standard meal containing [(14)C]octanoic acid and [(13)C]glycine over 30 min on 2 separate occasions. Gastric pH was measured for 90 min before and 240 min after the meal. 10 mm HCl was infused continuously at 1 mL/min into either the distal oesophagus or stomach in a 2-way crossover fashion for 60 min before and 240 min after the meal. Gastric emptying of solid and liquid were determined with breath tests.

RESULTS

Compared to gastric infusion, oesophageal infusion significantly decreased gastric acidity after the meal, but not before the meal and the magnitude of the decrease varied directly with gastric acidity. Gastric emptying of solid or liquid with oesophageal infusion was not significantly different from that with gastric infusion.

CONCLUSIONS

These findings support the hypothesis of the existence of a physiological oesophago-gastric feedback mechanism that might contribute to regulation of postprandial gastric acidity. Oesophageal acidification might decode gastric information and signal the stomach to decrease gastric acidity. Further studies are needed to assess the characteristics of such feedback mechanism in-patients with gastro-oesophageal reflux disease (GERD).

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.

Normal ambulatory 24-hour esophageal pH values in Koreans -a multicenter study-

Ambulatory 24-hr esophageal pH monitoring is considered the gold standard for diagnosing gastroesophageal reflux disease. The aim of this study was to establish normal values for gastroesophageal acid exposure in healthy Koreans. Fifty healthy volunteers (24 males and 26 females; mean age, 45 yr) without reflux symptoms and without reflux esophagitis or hiatal hernia on upper endoscopy underwent ambulatory 24-hr esophageal pH monitoring after esophageal manometry. The 95th percentiles for the reflux parameters were: the percent total time pH <4, 3.7%; the percent upright time pH <4, 5.7%; the percent supine time pH <4, 1.0%; the number of reflux episodes with pH <4, 76.5; the number of reflux episodes with pH <4 for >5 min, 1.5; the duration of the longest episode, 12.5 min; and the composite score, 14.2. Age and gender were not associated with any of the pH parameters. In conclusion, physiological gastroesophageal reflux occurs in healthy Koreans. These normal esophageal pH values will provide reference data for clinical and research studies in Korea.

Predictors of symptomatic and objective outcomes after surgical reintervention for failed antireflux surgery

BACKGROUND

Recurrent gastro-oesophageal reflux disease (GORD) and troublesome dysphagia after primary antireflux surgery are treated successfully by reoperation in 70 per cent of patients. Identifying predictors of outcome could allow selection of patients likely to benefit from further surgery. The aim was to identify such predictors in patients reoperated on for recurrent GORD or troublesome dysphagia.

METHODS

Between 1994 and 2005, 83 patients (mean(s.d.) age 47.2(14.4) years; 47 men) with recurrent GORD and 47 (aged 50.7(13.4) years; 18 men) with troublesome dysphagia had further surgery. The predictive values of demographic, anatomical and manometric variables, and 24-h pH monitoring were analysed with respect to symptomatic and objective outcomes in each group.

RESULTS

None of the factors included in a multivariable analysis predicted outcome after surgery for recurrent GORD. Independent predictors of symptomatic outcome after reoperation for dysphagia were amplitude of distal oesophageal contractions (odds ratio (OR) 1.613 (95 per cent confidence interval (c.i.) 1.087 to 2.393); P = 0.017), intrathoracic wrap migration (OR 0.077 (0.003 to 1.755); P = 0.108) and an abdominal approach (OR 0.012 (0.001 to 0.337); P = 0.009).

CONCLUSION

Low-amplitude distal oesophageal contractions, intrathoracic wrap migration and an abdominal approach were significant predictors of an unsuccessful symptomatic outcome after reoperation for troublesome dysphagia.

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

BACKGROUND AND OBJECTIVE

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

PATIENTS AND METHOD

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

RESULTS

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

CONCLUSIONS

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

Occurrence of nighttime gastroesophageal reflux in disturbed and normal sleepers

BACKGROUND & AIMS

It is not uncommon in a sleep laboratory to encounter individuals who have complaints of disturbed sleep, but who do not meet the criteria for a sleep disorder when evaluated by polysomnography. Because gastroesophageal reflux is known to occur in many individuals without their awareness, it is possible that some of these individuals might be suffering from reflux that is disturbing their sleep.

METHODS

Eighty-one individuals with complaints of disturbed or unrefreshing sleep, but no complaints of heartburn, were recruited. A comparison group of 39 individuals with neither sleep nor heartburn complaints also was studied. Both groups were studied on 2 separate occasions by simultaneous polysomnography and pH monitoring to detect the presence of nighttime gastroesophageal reflux and to determine sleep outcomes.

RESULTS

In the disturbed-sleep group 27% of subjects had at least one reflux event compared with 33% in the normals. In the subjects who experienced reflux, the disturbed-sleep group had a significantly greater percentage of acid exposure time compared with the normals (9.5% vs 1.6%; P < .05). Participants in the disturbed-sleep group also had a longer sleep-onset latency (P < .05) and less total sleep time (P < .05) compared with the normal sleepers.

CONCLUSIONS

Among individuals with complaints of disturbed sleep, there was a subset of individuals who had significant gastroesophageal reflux. We speculate that sleep-related gastroesophageal reflux may play a role in producing disturbed sleep in individuals without heartburn and otherwise unexplained sleep disturbance.

The Visick score: a good measure for the overall effect of antireflux surgery?

OBJECTIVE

In scoring the outcome of antireflux surgery, it is extremely difficult to combine the effect on reflux symptoms and esophageal acid exposure in one and the same single system - the Visick score revisited. The aim of this study was to correlate subjective outcome variables and objective outcome variables in an attempt to come to an overall reproducible scoring system.

MATERIAL AND METHODS

From 1997 to 1999, a randomized trial was set up to compare 98 patients who had undergone laparoscopic Nissen fundoplication (LNF) with 79 patients treated with conventional Nissen fundoplication (CNF). All patients were requested to complete a questionnaire, before and 3, 6, 12, 24 and 60 months after surgery. A subgroup of 87 patients agreed to undergo objective evaluation by pH-metry. The results of all these assessments were correlated with the effect of surgery on the Visick score.

RESULTS

After LNF and CNF, 79 and 69 patients, respectively, completed the questionnaires. After 5 years, complaints about heartburn, regurgitation and dysphagia were still significantly improved in the majority of patients, but in these groups, 6, 3 and 27% of patients, respectively, experienced deterioration. Visick score I or II (complaints resolved or improved) was recorded by 87% of patients. The Visick score correlated with the reduction of postoperative reflux symptom grades for heartburn, but not with the reduction of regurgitation, dysphagia and esophageal acid exposure.

CONCLUSIONS

Although this study shows that the Visick score can be applied to monitor the subjective effect of primary antireflux surgery as it correlates well with the most prominent symptom of GERD (heartburn), it also underlines the difficulty in adequately scoring symptomatic outcome of antireflux surgery.

Ninety-six-hour wireless oesophageal pH monitoring following proton pump inhibitor administration in NERD patients

BACKGROUND

Comparative studies of proton pump inhibitors (PPIs) have revealed that acid reflux is influenced by PPI treatment, formulations and dosing regimens. Wireless pH capsules have circumvented some of the limitations of conventional catheter-based pH testing with the additional advantage of 96-h recording periods.

AIM

To clarify the effectiveness of intra-oesophageal acid suppression by omeprazole, pantoprazole and lansoprazole in non-erosive reflux disease patients through a 4-day monitoring of oesophageal pH and related symptoms.

METHODS

Twenty-four patients with typical symptoms of gastro-oesophageal reflux disease were enrolled and administered upper endoscopy and placement of a wireless pH capsule. Patients randomly received omeprazole, pantoprazole or lansoprazole for 3 days after the first 24 h. Symptom-reflux associations were expressed using the symptom index (SI).

RESULTS

All patients completed the study. Significant decrease in acid exposure occurred on day 2 and in each successive day in all groups. Pantoprazole and omeprazole are more effective than lansoprazole at inducing a normalization of intra-oesophageal acid exposure at days 2 and 3. Significant reduction in SI at day 2 was observed.

CONCLUSIONS

Four-day ambulatory oesophageal pH monitoring is feasible and safe. Omeprazole, pantoprazole and lansoprazole have an equivalent potency for normalizing intra-oesophageal acid exposure after 3 days of treatment in non-erosive reflux disease patients.

Normal 24-hour Ambulatory Esophageal pH Values in Koreans

BACKGROUND/AIMS

Twenty-four-hour ambulatory esophageal pH monitoring is considered the gold standard for diagnosing gastroesophageal reflux disease. The aim of this study was to quantify normal distal esophageal acid parameters in healthy Koreans.

METHODS

Thirty healthy adults who were not on medication and were free from gastrointestinal symptoms were analyzed. Ambulatory esophageal acid (pH <4) exposure parameters were recorded at 5 cm above the lower esophageal sphincter.

RESULTS

The 95th percentiles for reflux parameters assessed in the distal esophagus were as follows: percentage of total time with pH <4, 5.10%; percentage of upright time with pH <4, 7.88%; percentage of supine time with pH <4, 4.00%; number of reflux episodes, 62.7; number of reflux episodes with pH <4 for >5 minutes, 5.3; and the longest single acid-exposure episode, 21.3 minutes.

CONCLUSIONS

Physiological gastroesophageal reflux occurs frequently in healthy Koreans. These data provide a reference range that could be utilized in studies involving Korean subjects.

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.