Clinical impact of different cut-off values in high-resolution manometry systems on diagnosing esophageal motility disorders.

BACKGROUND: The values of the parameters in the Chicago classification measured by a high-resolution manometry (HRM) system with the Unisensor catheter (Starlet) are significantly different from those measured by the ManoScan. The contraction vigor is categorized by values of the distal contractile integral (DCI) in the Chicago classification v3.0; however, reference values of the DCI in the Starlet and the clinical impact of the different reference values in the Starlet and ManoScan on diagnosing esophageal motility disorders are not known. METHODS: We evaluated data from a previous report in which ManoScan and Starlet were compared in the same subjects. The DCI values in each system were compared and reference DCI values were calculated. Moreover, diagnoses assessed by Starlet using reference values in ManoScan were compared with those using calculated reference values and those assessed by ManoScan. RESULTS: There was a significant positive correlation between the DCI values measured by ManoScan and those measured by Starlet (r = 0.80, p < 0.01). Based on a linear functional relationship considering measurement errors, the reference DCI values for diagnosing failed, weak and hypercontractile contraction vigor were calculated as 590.6, 1011.3 and 10,085.8 mmHg-s-cm, respectively, in the Starlet. Therefore, the proposed reference values in the Starlet were 500, 1000 and 10,000 mmHg-s-cm, respectively. When the reference values in the ManoScan were used in the Starlet data, approximately 30% of subjects were diagnosed inappropriately. This issue was resolved using the proposed reference values in the Starlet. CONCLUSION: Recognizing systemic differences in HRM systems is important.

Increase of transient lower esophageal sphincter relaxation associated with cascade stomach.

We previously reported that cascade stomach was associated with reflux symptoms and esophagitis. Delayed gastric emptying has been believed to initiate transient lower esophageal sphincter relaxation (TLESR). We hypothesized that cascade stomach may be associated with frequent TLESR with delayed gastric emptying. Eleven subjects with cascade stomach and 11 subjects without cascade stomach were enrolled. Postprandial gastroesophageal manometry and gastric emptying using a continuous 13C breath system were measured simultaneously after a liquid test meal. TLESR events were counted in early period (0-60 min), late period (60-120 min), and total monitoring period. Three parameters of gastric emptying were calculated: the half emptying time, lag time, and gastric emptying coefficient. The median frequency of TLESR events in the cascade stomach and non-cascade stomach groups was 6.0 (median), 4.6 (interquartile range) vs 5.0, 3.0 in the early period, 5.0, 3.2 vs 3.0, 1.8 in the late period, and 10.0, 6.2 vs 8.0, 5.0 in the total monitoring period. TLESR events were significantly more frequent in the cascade stomach group during the late and total monitoring periods. In contrast, gastric emptying parameters showed no significant differences between the two groups. We concluded that TLESR events were significantly more frequent in persons with cascade stomach without delayed gastric emptying.

New endoscopic classification of cascade stomach, a risk factor for reflux esophagitis.

BACKGROUND: We recently demonstrated that cascade stomach detected by barium studies was correlated with upper gastrointestinal symptoms. We developed a new endoscopic classification of cascade stomach and examined its relationship with reflux esophagitis. METHODS: Study 1: the classification (grades 0-3) was based on detecting a ridge that runs from the cardia toward the anterior wall crossing the greater curvature. Inter-observer variation was evaluated by kappa statistics when ten experienced endoscopists used this classification three times each. Study 2: in 710 consecutive subjects (500 men and 210 women) undergoing endoscopic screening, the grade of cascade stomach and incidence of reflux esophagitis were compared. RESULTS: In study 1, the kappa values at the third assessment were 0.85, 0.58, 0.50, and 0.78 for each grade, respectively, while overall agreement was 0.68. In study 2, the incidence of reflux esophagitis in men was 20 % in grade 0, 17 % in grade 1, 25 % in grade 2, and 30 % in grade 3, showing significant differences. Among women, the incidence of reflux esophagitis in each grade was 9, 3, 6, and 35 %, respectively, also showing significant differences. Multivariate analysis showed that independent risk factors for reflux esophagitis were cascade stomach (odds ratio = 2.20), body mass index, and hiatus hernia in men, as well as cascade stomach (odds ratio = 9.01) and smoking tobacco in women. CONCLUSIONS: This endoscopic classification of cascade stomach showed acceptable inter-observer variation. Cascade stomach is a risk factor for reflux esophagitis.

Liquid-containing Refluxes and Acid Refluxes May Be Less Frequent in the Japanese Population Than in Other Populations: Normal Values of 24- hour Esophageal Impedance and pH Monitoring.

BACKGROUND/AIMS: Twenty-four-hour esophageal impedance and pH monitoring allows detection of all types of reflux episodes and is considered the best technique for identifying gastroesophageal refluxes. However, normative data for the Japanese population are lacking. This multicenter study aimed to establish the normal range of 24-hour esophageal impedance and pH data both in the distal and the proximal esophagus in Japanese subjects. METHODS: Forty-two healthy volunteers (25 men and 17 women) with a mean ± standard deviation age of 33.3 ± 12.4 years (range: 22-72 years) underwent a combined 24-hour esophageal impedance and pH monitoring. According to the physical and pH properties, distal or proximal esophageal reflux events were categorized. RESULTS: Median 45 reflux events occurred in 24 hours, and the 95th percentile was 85 events. Unlike previous reports, liquid-containing reflux events are median 25/24 hours with the 95th percentile of 62/24 hours. Acidic reflux events were median 11/24 hours with the 95th percentile of 39/24 hours. Non-acidic gas reflux events were median 15/24 hours with the 95th percentile of 39/24 hours. Proximal reflux events accounted for 80% of the total reflux events and were mainly non-acidic gas refluxes. About 19% of liquid and mixed refluxes reached the proximal esophagus. CONCLUSIONS: Unlike previous studies, liquid-containing and acidic reflux events may be less frequent in the Japanese population. Non-acidic gas reflux events may be frequent and a cause of frequent proximal reflux events. This study provides important normative data for 24-hour impedance and pH monitoring in both the distal and the proximal esophagus in the Japanese population.

Evaluation of proton pump inhibitor-resistant nonerosive reflux disease by esophageal manometry and 24-hour esophageal impedance and pH monitoring.

BACKGROUND: Patients with proton pump inhibitor (PPI)-resistant nonerosive reflux disease (NERD) include subgroups that have markedly different pathophysiology. This study aimed to clarify the pathophysiology of NERD by esophageal manometry with 24-hour esophageal impedance and pH monitoring. METHODS: Eighteen consecutive outpatients referred to our expert center for functional gastrointestinal motility with suspected PPI-resistant NERD were enrolled. Manometry was performed to detect esophageal motility disorders. Subsequently, 24-hour esophageal impedance and pH monitoring was done while patients were on PPI therapy. RESULTS: Manometry revealed 1 case of achalasia, 1 case of nutcracker esophagus and 3 cases of diffuse esophageal spasm. Three patients had ineffective esophageal motility, with impedance and pH monitoring being performed in 2 of them. Esophageal acid exposure (%time pH <4) was normal in both, but the symptom index (SI) was positive for nonacidic reflux in 1 patient. One of the 10 patients with normal esophageal motility had abnormal esophageal acid exposure. The SI was positive for weakly acidic and nonacidic reflux in 3 of the remaining 9 patients with normal esophageal acid exposure. Five of the other 6 patients seemed to have functional heartburn. CONCLUSION: A substantial percentage (28%) of patients with suspected PPI-resistant NERD had primary esophageal motility disorders. Both nonacidic reflux and weakly acidic reflux are important contributors to the symptoms of patients with PPI-resistant NERD. Esophageal manometry is required to exclude motility disorders, while 24-hour esophageal impedance and pH monitoring is invaluable for assessing symptom-reflux associations and the indications for fundoplication in patients with suspected PPI-resistant NERD.

More severe upper gastrointestinal symptoms associated with non-erosive reflux disease than with erosive gastroesophageal reflux disease during maintenance proton pump inhibitor therapy.

BACKGROUND: During maintenance proton pump inhibitor (PPI) therapy, patients with gastroesophageal reflux disease (GERD) sometimes complain of upper gastrointestinal symptoms. AIM: To evaluate upper gastrointestinal symptoms in patients on maintenance PPI therapy for erosive GERD or non-erosive reflux disease (NERD) without endoscopic mucosal breaks by using a new questionnaire. METHODS: At Gunma University Hospital over a 12-month period during 2011-2012, we enrolled 30 consecutive patients with erosive GERD and 46 patients with NERD. All patients had been on maintenance PPI therapy for more than 1 year. We used the modified frequency scale for the symptoms of GERD (mFSSG) questionnaire to assess upper gastrointestinal symptoms. We also asked patients about their satisfaction with maintenance therapy and whether they wished to change their current PPI. RESULTS: The NERD patients had significantly higher symptom scores than the erosive GERD patients. There was no difference in the treatment satisfaction rate between patients with erosive GERD and NERD, but more patients with NERD wanted to change their PPI therapy. There was no difference in the mFSSG score between NERD patients who wished to change their current PPI therapy and those who were satisfied with it. CONCLUSIONS: During maintenance PPI therapy, upper gastrointestinal symptoms were more severe in NERD patients than in patients with erosive GERD. NERD patients often wished to change their PPI therapy, but this was not dependent on the severity of their upper GI symptoms.

Gastrointestinal motility and functional gastrointestinal diseases.

Digestive tract motility patterns are closely related to the pathophysiology of functional gastrointestinal diseases (FGID), and these patterns differ markedly between the interdigestive period and the postprandial period. The characteristic motility pattern in the interdigestive period is so-called interdigestive migrating contraction (IMC). IMCs have a housekeeping role in the intestinal tract, and could also be related to FGID. IMCs arising from the stomach are called gastrointestinal IMCs (GI-IMC), while IMCs arising from the duodenum without associated gastric contractions are called intestinal IMCs (I-IMC). It is thought that I-IMCs are abnormal in FGID. Transport of food residue to the duodenum via gastric emptying is one of the most important postprandial functions of the stomach. In patients with functional dyspepsia (FD), abnormal gastric emptying is a possible mechanism of gastric dysfunction. Accordingly, delayed gastric emptying has attracted attention, with prokinetic agents and herbal medicines often being administered in Japan to accelerate gastric emptying in patients who have anorexia associated with dyspepsia. Recently, we found that addition of monosodium L-glutamate (MSG) to a high-calorie liquid diet rich in casein promoted gastric emptying in healthy men. Therefore, another potential method of improving delayed gastric emptying could be activation of chemosensors that stimulate the autonomic nervous system of the gastrointestinal tract, suggesting a role for MSG in the management of delayed gastric emptying in patients with FD.

Development and evaluation of a modified Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease to distinguish functional dyspepsia from non-erosive reflux disease.

BACKGROUND AND AIM: The Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease (FSSG) is the standard questionnaire used in Japan for the diagnosis of gastroesophageal reflux disease (GERD) and assessment of the response to treatment. We modified the FSSG in order to assess dyspepsia symptoms, and evaluated the modified questionnaire. METHODS: We modified the FSSG by adding two questions on interdigestive and postprandial epigastric pain. We then assessed the modified FSSG with 100 new untreated symptomatic patients presenting to hospital and in 200 subjects undergoing health checks. Endoscopic assessment of the esophagogastric junction was performed according to the modified Los Angeles classification with addition of Grade N (normal appearance) and Grade M (minimal change). Endoscopic images were assessed by five experienced endoscopists blinded to the questionnaire results. RESULTS: The 100 new patients included 16 with erosive GERD (>Grade A), 12 with peptic ulcer, and two with gastric cancer. Among the 70 patients with no evidence of organic disease, the modified FSSG diagnosed functional dyspepsia (FD) in 41 and non-erosive gastric disease (NERD) in 29. A significant difference was seen in the dyspepsia score between patients with FD and NERD. Subjects with endoscopic GERD undergoing health checks had significantly higher scores for all symptoms, reflux symptoms, and dyspeptic symptoms on the modified FSSG. CONCLUSION: The modified FSSG can clearly distinguish FD from NERD, and is useful for the assessment of dyspeptic symptoms.