Number Of Reflux Episodes Research Articles

Use of multiple channel pH monitoring for evaluation of ultra-distal reflux in patients after fundoplication for treatment of Barrett's esophagus

Dysplasia and esophageal adenocarcinoma may arise in patients with Barrett's esophagus after fundoplication esophageal pH monitoring showing no acid in esophagus. This suggests the need to develop methodology to evaluate the occurrence of ultra-distal reflux (1cm above the LES). The objective of the study was to compare acid exposition in three different levels: 5cm above the upper border of the LES, 1cm above the LES and in the intrasphincteric region. Eleven patients with Barrett's esophagus after Nissen fundoplication with no clinical, endoscopic and radiologic evidence of reflux were selected. Four-channel pH monitoring took place: channel A, 5cm above the upper border of the LES; channel B, 1cm above the LES; channel C, intrasphincteric; channel D, intragastric. The results of channels A, B and C were compared. There was significant increase in number of reflux episodes and a higher fraction of time with pH <4.0 in channel B compared to channel A. There was significant decrease in fraction of time with pH <4.0 in channel B compared to channel C. Two cases of esophageal adenocarcinoma were diagnosed in the studied patients. The region 1cm above the upper border of the LES is more exposed to acid than the region 5cm above the upper border of the LES, although this exposure occurred in reduced levels. The region 1cm above the upper border of the LES is less exposed to acid than the intrasphincteric region.

Acid-Suppressive Effect of Rabeprazole 5 mg and 10 mg Once Daily by 24-Hour Esophageal pH Monitoring in Patients with Non-erosive Reflux Disease in Japan: A Multicenter, Randomized, Parallel-Group, Double-Blind Pharmacodynamic Study

Acid suppression induced by rabeprazole 5 mg in patients with NERD has not been reported in the literature. The objective of this study was to investigate gastroesophageal acid suppression in NERD patients by rabeprazole 5 mg and 10 mg/day. Subjects were grade M (minimal changes) NERD patients. Twenty-two patients not responding to open label antacid therapy entered a double-blind treatment phase in which rabeprazole 5 mg or 10 mg/day for four weeks were compared. Twenty-four-hour esophageal pH monitoring was performed before and on treatment (at week 4) to assess the pharmacodynamic effect of these doses of rabeprazole. The frequency of heartburn episodes and the number of acid reflux episodes in the esophagus corresponded well in grade M NERD patients (r=0.44, P=0.042). Median percentage of time at pH<4 was 4.3% before treatment and 1.1% on treatment with rabeprazole 5 mg (change from baseline; -2.5%), whereas the median percentage of time at pH<4 in the rabeprazole 10 mg group was 7.4% before treatment and 0.5% on treatment (change from baseline; -6.6%). Likewise, treatment-related changes of median number of reflux episodes were -18.0 with rabeprazole 5 mg and -44.0 with rabeprazole 10 mg. For each esophageal pH data, no significant differences were observed between the two groups (P=0.377, P=0.077). Administration of 5 mg and 10 mg rabeprazole sufficiently inhibited pathological gastroesophageal acid reflux and relieved heartburn episodes in NERD patients who did not respond to an antacid. Further investigation would be necessary to determine proper usage of the two doses.

Temporal relationship between gastroesophageal reflux and rate of gastric emptying in children

There are conflicting reports for the relationship of reflux and the gastric emptying rate. In addition, the acquisition period is not well defined for the gastroesophageal reflux studies. The aim of our study was to evaluate the temporal distribution of the reflux episodes and to evaluate whether the gastric emptying rate changed with the gastroesophageal reflux time or amount. We used radionuclide scintigraphy to evaluate 211 pediatric patients (0-10 years of age). Scintigraphic studies were performed by acquiring 15 s images for 1 h in a supine position after ingesting milk containing 0.5 mCi (18.5 MBq) Tc-99m colloid. Reflux episodes were calculated every 10 min for each patient who had reflux. The gastric emptying rate was measured by drawing an region of interest over the gastric activity. Gastric reflux was observed in 104 patients (49.28%). The number of reflux episodes was higher in the first and second 10 min (33.7 and 29.1% respectively). The lowest reflux episode was observed in the last 10 min (between 50 and 60 min) (2.6%) suggesting that the reflux episode was decreasing by the gastric emptying. Within the first 30 min, reflux was observed in 98 of 104 patients (94.23%). The gastric emptying rate was calculated to be 73 min in patients with a higher incidence of reflux and 62 min in patients who had delayed and lower incidence of reflux episodes. In 104 patients, the average gastric emptying rate was 71.60 min. There were no significant differences in the gastric emptying rates between patients who had reflux episodes beginning in the first 30 min of the study and those who had reflux episodes in the last 30 min of the study (P>0.05). This study has suggested that the number of reflux episodes were not related with the gastric emptying rate. However, reflux could be observed in a higher frequency before gastric emptying, which also suggested that a 30-min period may be sufficient when reflux is shown early. In negative cases, a 60-min acquisition time is recommended for the diagnosis of gastroesophageal reflux.

Computer analysis of 24-h esophageal impedance signals

Objective. To assess the accuracy of newly developed software for detection of gastro-esophageal reflux episodes in ambulatory 24-h impedance tracings. Material and methods. 24-h esophageal impedance recordings obtained from 60 consecutive patients with reflux symptoms were used in this study. The impedance tracings of the first 10 consecutive patients were analyzed manually by three investigators. Liquid-containing reflux episodes and their proximal extent were scored. A consensus between the three investigators was used as a gold standard. Computer analysis using dedicated software was performed, and the results were compared with the results of the consensus agreement. In addition, in order to assess the accuracy of symptom association analysis 24-h impedance tracings of all 60 patients were analyzed both manually by one investigator and using computer software. The number of reflux episodes and the results of symptom association analysis obtained by the human and computer analysis software were compared. Results. The consensus meeting resulted in a total of 625 reflux episodes. The mean sensitivity and the percentage of true-positives of analysis by individual investigators was 89 ± 1% and 94 ± 1%, respectively. Automated analysis had a sensitivity of 73 ± 4% and a proportion of true-positive reflux episodes of 62 ± 8%. Symptom association analysis performed by the computer and a human observer showed concordant results in 83% of the patients. Conclusions. Although not as good as manual analysis by experts, computer analysis can be a helpful tool to identify reflux episodes and to assess the relationship between reflux episodes and symptoms.

How to Interpret Esophageal Impedance pH Monitoring

Esophageal impedance pH monitoring provides quantitative data on esophageal acid exposure and has the ability to correlate the symptoms with acid exposure events. The nomenclature for the reflux patterns detected in impedance pH monitoring as well as the normal values have been determined. Data interpretation is similar to 24-hour pH monitoring, ie, searching for an increase in the number of reflux episodes, prolonged acid or volume exposure or increased numbers of proximal reflux events. In particular, the key clinical measurements for impedance testing on proton pump inhibitor therapy are the number of acid and non-acid reflux episodes and their relationship with the symptoms using the symptom index or symptom-association probability.

T1702 Cytokines Regulate Tight-Junction Structure and Function in the Rat Chronic Acid Esophagitis Model

tomy had more frequently erosive esophagitis than patients with cholecystectomy (p<0.05). Conclusions: Colecystectomy do not increase the overall number of reflux episodes compared to patients without colecystectomy, but modifies significantly the composition of the refluxate raising the frequency of nonacid reflux. The different proportion of acid/nonacid reflux may explain the higher presence of erosive esophagitis in nCCE patients.

Beyond Acid Suppression: New Pharmacologic Approaches for Treatment of GERD

Proton pump inhibitors are highly successful in treating gastroesophageal reflux disease, but a significant proportion of patients have persistent symptoms from weakly or nonacidic reflux. Transient lower esophageal sphincter relaxation (TLESR) represents the dominant mechanism of gastroesophageal reflux and has therefore become the most intensely investigated therapeutic target. The triggering of TLESR involve the vagal pathways and the gamma-aminobutyric type B (GABA(B)) and metabotropic glutamate type 5 (mGluR5) receptors. Baclofen is a GABA(B) receptor agonist that is effective in inhibiting TLESR and reducing the number of reflux episodes, but is associated with significant central nervous system (CNS) side effects. The newer GABA(B) agonists, such as AZD9343 and AZD3355, and mGluR5 antagonists, such as 2-methyl-6-(phenylethynyl)-pyridine (MPEP), have been shown in small, randomized, controlled trials to have comparable efficacy to baclofen, but possibly a more favorable CNS side effect profile. Cannibinoid agonists, such as Delta(9)-THC, have also been demonstrated to reduce TLESRs and reflux events respectively. Macrolide antibiotics (eg, erythromycin) show early promise in a select group of patients with possible reflux associated post-lung transplant problems.

The novel, peripherally restricted GABA B receptor agonist lesogaberan (AZD3355) inhibits acid reflux and reduces esophageal acid exposure as measured with 24-h pHmetry in dogs

While patients with symptoms of gastroesophageal reflux disease generally respond well to proton pump inhibitors, 20–30% continue to experience troublesome symptoms. In such cases, agents that target transient lower esophageal sphincter (LES) relaxation may be useful as add-on therapy to proton pump inhibitors. The GABA B receptor agonist baclofen inhibits transient LES relaxation but it is not an ideal agent due to central nervous system activity. Lesogaberan (AZD3355) is a peripherally restricted GABA B receptor agonist with limited central nervous system activity that inhibits transient LES relaxation in dogs. In the present study, the comparative effects of lesogaberan (7 µmol/kg) and baclofen (2.8 μmol/kg) on reflux were studied in dogs using 24-h pHmetry. Drugs (or vehicle control) were administered orally prior to the first meal of the day, and the number of reflux episodes (pH < 4 for ≥ 5 s) and acid exposure time were computed for the 24-h monitoring period. The mean (S.E.M.) number of reflux episodes/24 h was 4.6 (0.4) and 6.4 (0.6) for lesogaberan and baclofen, respectively, versus 10.7 (0.5) for control ( P < 0.0001 for both). Acid exposure time was 51.2 (4.5) min for control versus 23.6 (3.8) min for lesogaberan ( P < 0.0001) and 35.4 (6.5) min with baclofen ( P = 0.05). It is concluded that lesogaberan significantly reduces acid reflux in dogs, with comparable efficacy to baclofen.

The role of psychological distress in laryngopharyngeal reflux patients: a prospective questionnaire study

To determine the role of psychological distress in laryngopharyngeal reflux patients and evaluate the correlation between symptoms, laryngeal signs, pH monitoring results and psychological profile. Prospective study. Hanyang University Hospital, a university teaching hospital and tertiary referral center. One hundred and six patients who were diagnosed with laryngopharyngeal reflux by 24-h ambulatory double probe pH monitoring and 119 healthy controls visiting our health promotion center from January 2006 to June 2007. The psychological profile of laryngopharyngeal reflux patients measured by the Symptom Checklist-90-Revised questionnaire were evaluated and compared with those of healthy controls. The correlation between reflux symptom index, reflux finding score, parameters of pH monitoring and the Symptom Checklist-90-Revised profiles were also evaluated. On the Symptom Checklist-90-Revised questionnaire, the total mean T-scores of the nine symptom dimensions and three global indices of the laryngopharyngeal reflux patients were all below 50. The Global Severity Index, which indicates overall psychological distress, was normal in all of the patients. On comparison with the control group, no statistically significant difference was noted in the psychological profile except on the Somatisation scale where laryngopharyngeal reflux patients showed significantly higher scores. Reflux symptom index showed significant positive correlation with the number of reflux episodes, percentage of time which pH fell below 4 in total positions, and DeMeester score of the upper probe. The nine symptom dimensions and three global indices of Symptom Checklist-90-Revised questionnaire did not show any correlation with reflux symptom index, reflux finding score and the parameters of the 24-h ambulatory double probe pH monitoring. Laryngopharyngeal reflux patients did not demonstrate any significant level of psychological distress and their symptom severity showed significant positive correlation with reflux severity.

Rabeprazole Combined with Hydrotalcite is Effective for Patients with Bile Reflux Gastritis after Cholecystectomy

Regardless of surgical technique, patients who have undergone cholecystectomy appear to be predisposed to the development of bile reflux gastritis. To assess the efficacy of rabeprazole and hydrotalcite in patients with bile reflux gastritis after cholecystectomy. Postcholecystectomy patients with bile reflux gastritis confirmed by endoscopy and 24 h gastric bilirubin monitoring were randomly assigned to one of four eight-week treatments: observation (group A), rabeprazole alone (group B), hydrotalcite alone (group C) and rabeprazole in combination with hydrotalcite (group D). Endoscopy and 24 h gastric bilirubin monitoring were repeated in all patients after treatment. Dyspeptic symptoms of abdominal pain, bloating, heartburn, bitter taste, endoscopic and histological finding, and biliary reflux were evaluated before and after treatment. After administering medication, patient symptoms in groups B, C and D were relieved - most significantly in group D (P<0.05). There were no significant differences in endoscopic hyperemia and histological inflammation among the groups (P>0.05). However, histological activity, the number of reflux episodes and the number of reflux episodes lasting longer than 5 min were significantly decreased only in group D (P<0.05). The total per cent of bilirubin absorption (value of 0.14 units or greater) time was decreased in groups B, C and D, and most significantly in group D (P<0.05). Rabeprazole combined with hydrotalcite is an effective therapeutic option in the treatment of patients with bile reflux gastritis after cholecystectomy.

Arbaclofen Placarbil Decreases Postprandial Reflux in Patients With Gastroesophageal Reflux Disease

Arbaclofen placarbil (AP), previously designated as XP19986, is an investigational prodrug of the active R-isomer of baclofen, a gamma-aminobutyric acid agonist reflux inhibitor. The aim of this study was to assess the efficacy and safety of AP for decreasing meal-induced reflux episodes in patients with gastroesophageal reflux disease (GERD). We conducted a multicenter, randomized, double-blind, crossover study comparing single doses of AP with placebo. Different patients were enrolled at each of four escalating AP doses: 10, 20, 40, and 60 mg. Enrolled patients had GERD symptoms at least three times a week and 20 reflux episodes on impedance/pH monitoring over a period of 2 h. During study visits separated by periods of 3-7 days, patients received single doses of AP or placebo, followed by high-fat meals 2 and 6 h after treatment. The primary end point was the number of reflux episodes over 12 h after treatment. A total of 50 patients were treated; efficacy analysis included 44 patients who received both AP and placebo and had technically satisfactory impedance/pH data. For the combined data from all dose cohorts, there was a statistically significant (P=0.01) decrease in reflux episodes over 12 h after treatment with AP compared with placebo. The mean (s.d.) number of reflux episodes over 12 h after AP treatment was 50.5 (27.2), with a mean reduction of 10.4 (23.9) episodes (17%) compared with placebo, for which a mean (s.d.) number of 60.9 (35.3) episodes was observed. Heartburn events associated with reflux were reduced during treatment with AP compared with placebo. AP seemed to be the most efficacious in the 60-mg dose group, and was well tolerated at all dose levels. AP decreased reflux and associated symptoms with good tolerability in patients with GERD.

547 A Study On the Intercellular Space of Squamous Epithelium in Lower-Esophagus with Light Microscopy in the Diagnosis of GERD

(between 53.0 and 66.4%) or alkaline (between 0.5 and 1.3%) was similar in all groups. However, the median nadir pH of reflux episodes decreased with increasing severity of mucosal damage and was highest in the controls (pH 3.8) and lowest in the patients with Barrett (pH 2.5). Besides an increased number of reflux episodes, the acid clearance time of the acid reflux episodes was significantly longer in the patients with severe esophagitis (134±20 s) and Barrett's esophagus (104±21 s) compared to the controls (58±30 s), patients with NERD (73±14 s), LA A (84±49 s) and LA B (70±35 s). Comparison with normal values revealed that none of the controls, 40% of the patients with NERD, 50% of the patients with LA A, 80% of the patients with LA B and all patients with LA C/D or Barrett's esophagus had an abnormally high total number of reflux episodes. In the patients with severe esophagitis a significantly higher percentage of reflux episodes reached the proximal esophagus (43.8%) compared to the patients with Barrett's esophagus (19.2%). Conclusions: Not only the number of acid reflux episodes but also the number of weakly acidic reflux episodes is increased in patients with increasing severity esophagitis and Barrett's esophagus. However, a large overlap between the groups exists which implies that comparison to normal values is of limited relevance. In patients with Barrett's esophagus fewer reflux episodes reach the (more sensitive) proximal esophagus which might explain their low sensitivity to reflux.

Patterns of laryngopharyngeal and gastroesophageal reflux

Double-probe, 24-hour pH monitoring remains the 'gold standard' for the diagnosis of laryngopharyngeal reflux disease, even though there is no consensus on how to interpret the data collected. Tetra-probe, 24-hour pH monitoring was performed in 56 patients with suspected laryngopharyngeal reflux, in order to investigate patterns of laryngopharyngeal and gastroesophageal reflux. The number of reflux episodes and the total and percentage time periods spent with pH < 4.0 were correlated with the distance of the probe from the lower oesophageal sphincter. The number of reflux episodes and the total and percentage time periods with pH < 4.0 were greater when patients were upright (i.e. during the daytime). There were few laryngopharyngeal reflux events recorded for pH levels of <4.0; however, there were a significant number of laryngopharyngeal reflux events recorded for pH levels of <5.0, a level capable of causing laryngopharyngeal reflux disease. When a pH level of <5.0 was used, the number, total time and percentage time of laryngopharyngeal reflux episodes was greater during the supine period (i.e. during sleeping) in a quarter of the cases, compared with results when a pH of <4.0 was used. It is valid to use a pH level of 5.0 as indicative of laryngopharyngeal reflux in the hypopharynx.

Nonacid Reflux Episodes Reaching the Pharynx are Important Factors Associated With Cough

Gastroesophageal reflux is implicated in the pathogenesis of asthma and chronic cough. To date most studies have focused on acid reflux measured by pH below the upper esophageal sphincter (UES). The aim of this study was to assess the relationship between cough and reflux through the UES into the pharynx. Thirty-seven patients with asthma (19) and chronic cough (18) were recruited from the respiratory clinic. Reflux was monitored using a combined multichannel intraluminal impedance and pH probe by detecting (1) bolus reflux episodes within the esophagus and in the pharynx and (2) acidic reflux episodes within the esophagus and in the pharynx. All acid suppressive therapy was stopped for at least 7 days before the study. Demonstration of cough being linked to reflux was achieved using the symptom association probability (SAP). This was calculated using a 2-minute association window between symptoms and bolus entry into the esophagus. SAP was considered positive if >95%. A positive SAP for cough was noted in 7/26 patients reporting symptoms on the day of monitoring. Compared with SAP-negative patients, SAP-positive patients had both a greater number [median (interquartile range), 5(2 to 8) vs. 2(0 to 4), P<0.05] and a higher proportion of reflux episodes crossing the UES into the pharynx [25%(14% to 28%) vs. 7% (2% to 14%), P<0.02]. There was no difference in the number of reflux episodes or acid exposure time in the distal esophagus between SAP-positive and SAP-negative patients. Only 1% to 2% of episodes were detected by the pharyngeal pH sensor. Impedance detected pharyngeal reflux episodes are important factors in symptom production in cough patients.

M1839 Association Between Body Mass-Index and Increased Number of Reflux Episodes Is Present in Females But Not Males

M1839 Association Between Body Mass-Index and Increased Number of Reflux Episodes Is Present in Females But Not Males

Normal Values of 24-Hour Combined Esophageal Multichannel Intraluminal Impedance and pH Monitoring in the Chinese Population

Background: There is a lack of data on combined esophageal multichannel intraluminal impedance and pH (MII-pH) monitoring in the Chinese population. Goals: To define the normal range and compare the parameters to those of the Western population. Study: Healthy volunteers were recruited and underwent 24-hour ambulatory combined MII-pH monitoring. Gastroesophageal reflux episodes were detected and characterized by pH (acidic, weakly acidic and weakly alkaline reflux) and composition (liquid, mixed and gas reflux). Results: Seventy healthy volunteers (male:female 33:37) were recruited. The median and 95th percentile number of the total reflux episodes over 24 h in the Chinese population was 40 and 75, respectively, whereas the corresponding numbers of acidic, weakly acidic and weakly alkaline reflux episodes were 22 and 54, 16 and 40, and 0 and 4, respectively. Among all reflux episodes 53.3% were acidic, 44.7% were weakly acidic, and 2% weakly alkaline. More than half (52.4%) of the reflux episodes were mixed, 37.2% were liquid, and 10.4% were gas. A total of 26.6% of reflux episodes reached 15 cm above the lower esophageal sphincter. Male gender was associated with an increased number of acid, liquid, mixed and proximal reflux episodes (p < 0.05). Conclusions: This study provides normal values for the Chinese population. Differences between genders in impedance parameters required caution during data interpretation. The number of reflux episodes in the Chinese population was similar to that in the Western population.

Increased swallowing frequency in GORD is likely to be caused by perception of reflux episodes

Patients with gastro-oesophageal reflux disease (GORD) swallow air more frequently and have more gas-containing reflux episodes than healthy controls. One explanation for this phenomenon may be that GORD patients primarily swallow more frequently and, as a consequence, have more swallow- or transient lower oesophageal sphincter relaxation-associated reflux episodes. Another explanation may be that GORD patients swallow more often in response to perception of reflux episodes. The aim of this study was to differentiate between these two possible mechanisms. In 34 patients with typical reflux symptoms oesophageal 24-h pH-impedance monitoring was performed twice, once off and once on proton pump inhibitor (PPI) therapy. The number of reflux episodes and number of swallows and air swallows was evaluated. The symptom association probability (SAP) was used to distinguish patients with a good relationship between symptoms and reflux episodes (SAP+) from those who had not (SAP-). In both the SAP+ (n = 21) as SAP- patients (n = 13), the acid exposure time decreased during PPI therapy. In the SAP+ patients, the number of swallows decreased on PPI (829 +/- 85 off vs 701 +/- 79 on PPI, P < 0.05), whereas in the SAP- patients, the incidence of swallows (802 +/- 93 off vs 814 +/- 69 on PPI, P = NS) was not influenced by the PPI therapy. PPI therapy reduces the number of swallows in patients with a positive SAP, but not in those with a negative SAP. This finding supports the hypothesis that the increased incidence of swallows in GORD is brought about by responses to perceived reflux events.

The Effect of Thickened-Feed Interventions on Gastroesophageal Reflux in Infants: Systematic Review and Meta-analysis of Randomized, Controlled Trials

Currently, thickened feeds are increasingly being used to treat infants with gastroesophageal reflux, driven in large part by the baby food industry. Previous meta-analyses have shown that although thickened formulas do not seem to reduce measurable reflux, they may reduce vomiting. However, because data are limited, there is still uncertainty regarding the use of thickening agents. Our goal was to systematically evaluate and update data from randomized, controlled trials on the efficacy and safety of thickened feeds for the treatment of gastroesophageal reflux in healthy infants. The Cochrane Library, Medline, Embase, and CINAHL databases and proceedings of the European and North American pediatric gastroenterology conferences (from 2000) were searched in May 2008; additional references were obtained from reviewed articles. Only randomized, controlled trials that evaluated thickened feeds used in infants for at least several days for the treatment of gastroesophageal reflux were considered for inclusion. Three reviewers independently performed data extraction by using standard data-extraction forms. Discrepancies between reviewers were resolved by discussion between all authors. Only the consensus data were entered. Fourteen randomized, controlled trials with a parallel or crossover design, some with methodologic limitations, were included. Use of thickened formulas compared with standard formula significantly increased the percentage of infants with no regurgitation, slightly reduced the number of episodes of regurgitation and vomiting per day (assessed jointly or separately), and increased weight gain per day; it had no effect on the reflux index, number of acid gastroesophageal reflux episodes per hour, or number of reflux episodes lasting >5 minutes but significantly reduced the duration of the longest reflux episode of pH<4. No definitive data showed that one particular thickening agent is more effective than another. No serious adverse effects were noted. This meta-analysis shows that thickened food is only moderately effective in treating gastroesophageal reflux in healthy infants.

Lap-Band Impact on the Function of the Esophagus

The laparoscopic adjustable gastric band (LAGB) has been widely used to treat morbid obesity. There is conflicting data on its long-term effect on esophageal function. Our aim was to assess the long-term impact of the LAGB on esophageal motility and pH-metry in patients who had LAGB who had normal and abnormal esophageal function at baseline. Consecutive patients referred for bariatric surgery were prospectively enrolled. A detailed medical history was obtained, and esophageal manometric and 24-h pH evaluations were performed in standard fashion preoperatively and 6 and 12 months postoperatively; patients served as their own controls. Twenty-two patients completed manometric evaluation. Ten patients had normal manometric parameters at baseline; at 6 months, mean lower esophageal sphincter (LES) residual pressure increased significantly from baseline (3.9 +/- 2 vs. 8.9 +/- 4 mmHg, p = 0.014). At 12 months, the mean peristaltic wave duration increased from 3.6 +/- 1 at baseline to 6.8 +/- 2 s, p = 0.025 and wave amplitude decreased during the same period (98.7 +/- 22 vs. 52.3 +/- 24, p = 0.013). LES pressure and percent peristalsis did not differ significantly pre- and post-LAGB. Twelve patients had one or more abnormal manometric findings at baseline; at 12 months, LES pressure in these 12 patients decreased significantly (31.1 +/- 10 vs 23.6 +/- 7, p = 0.011) and wave amplitude was significantly reduced (125.9 +/- 117 vs 103 +/- 107, p = 0.039). LES residual pressure did not change significantly pre- and post-LAGB. Twenty-two individuals were evaluated for impact of Lap-Band on esophageal acid exposure. Sixteen of these patients had normal esophageal pH-metry values at baseline and had no significant changes in 12 months in any pH-metry measurement. Six patients had abnormal pH-metry values at baseline. Among these patients, time with pH < 4.0 and Johnson/DeMeester score did not change significantly during follow-up. There was a significant decrease in the number of reflux episodes from baseline to 6 months (159 +/- 48 vs. 81 +/- 61, p = 0.016). Abnormal manometric findings are frequently encountered post-LAGB. Increases in LES residual pressure and peristaltic wave duration were the most significant changes. LAGB is not associated with an increase in total esophageal acidification time. Further evaluation of the clinical significance of manometric abnormalities is warranted.

Normal 24-hour Ambulatory Esophageal pH Values in Koreans

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