Akihiko Kawakami

Transient Lower Esophageal Sphincter Relaxations (TLESRs) Are the Major Mechanism of Gastroesophageal Reflux but Are Not the Cause of Reflux Disease

In healthy subjects, the rate of acid reflux during transient lower esophageal sphincter relaxations (TLESRs) is more frequent at the proximal margin of the LES. In this study, we investigated the hypothesis that the rate of acid reflux at the proximal margin of LES during TLESRs is similar in reflux disease to that in healthy subjects. Concurrent esophageal manometry and pH monitoring were performed in the sitting position for 3 hr after a standard meal in 10 patients with reflux disease and 10 age-matched healthy controls. The rate of TLESRs in patients with reflux disease (5.0/hr [3.3–6.7]; median [interquartile range]) was similar to that of controls (4.5/hr [3.7–5.7]). The incidence of acid reflux 7 cm above the LES during TLESRs in patients (48.1% [27.2–71.4%]) was significantly higher than that in controls (10.9% [0.0–18.8%]) but there was no difference 2 cm above the LES (75.0 [69.2–87.5] vs. 74.3 [55.5–90.0%]). The rate of TLESRs and the incidence of acid reflux during TLESRs are not increased in reflux disease. These findings, therefore, indicate that reflux disease is not a disorder of TLESRs and relates more to the proximal extent of the refluxate.

Esophageal motility in Japanese patients with Barrett's esophagus

BackgroundThe prevalence of gastroesophageal reflux disease has been increasing in Japan as it has in Western countries, but Barrett’s esophagus (BE) is less common in Japan than in Western countries. The aim of this study, therefore, was to investigate esophageal motility and clinical characteristics in Japanese patients with BE.MethodsTen patients with BE were compared with ten patients with mild reflux esophagitis (RE), ten patients with severe RE, and ten healthy subjects of comparable age and sex. The prevalence of Helicobacter pylori was investigated in the patients with BE. The intraluminal microtransducer method was used to test for esophageal motility. Basal lower esophageal sphincter (LES) pressure was assessed by the rapid pull-through method. The esophageal wave after ten repeated 5-ml water swallowings at 30-s intervals was measured at 3, 8, 13, and 18 cm above the LES.ResultsThe basal LES pressure, the amplitude of the esophageal wave at 3 and 8 cm above the LES, and the frequency of primary peristalsis in the severe RE group and BE group were significantly lower than the values in the healthy subjects and the mild RE group. The amplitude of the esophageal wave 13 cm above the LES in the BE group was significantly lower than that in the healthy subjects and the mild RE group. There was no difference between the severe RE group and the BE group in the basal LES pressure and the amplitude of the esophageal wave. The frequency of primary peristalsis in the BE group, however, was significantly lower than that in the severe RE group. Nine of the ten patients with BE were H. pylori-negative.ConclusionsOur conclusions are that esophageal dysmotility in Japanese patients with BE represents an advanced stage of severe RE, and that most Japanese patients with BE are H. pylori-negative.

Effect of body position on lower esophageal sphincter pressure.

Abstract: This study examined the effect of body position on lower esophageal sphincter (LES) pressure. In 36 healthy subjects and 31 patients with reflux esophagitis, LES and intragastric pressures were measured with subjects in the supine and sitting positions by the intraluminal microtransducer method. LES pressure was significantly lower in the sitting position than in the supine position in both healthy subjects and patients with reflux esophagitis. Intragastric pressure was significantly higher in the sitting position than in the supine position in both healthy subjects and patients with reflux esophagitis, but this increase was less marked than the decrease in LES pressure in the sitting position. The overlap of LES pressure values between healthy subjects and patients with reflux esophagitis was lower in the sitting position than in the supine position. We conclude that the measurement of LES pressure in the sitting position reflects LES function more accurately.

Association between reflux esophagitis and/or hiatus hernia and gastric mucosal atrophy level in Japan

Background and Aims:  The mechanisms involved in reflux esophagitis (RE) are mainly esophageal motor dysfunction and abnormal esophageal acid exposure. Therefore the extent of gastric mucosal atrophy (GMA), which is related to gastric acid secretion, is an important factor in the development of RE. The aim of this study was to evaluate the prevalence of RE and hiatus hernia (HH) according to level of GMA.

The minimum pressure of the lower esophageal sphincter, determined by the rapid pull-through method, is an index of severe reflux esophagitis.

BackgroundBecause of the wide overlap between the groups, patients with reflux esophagitis (RE) cannot be distinguished from healthy subjects by basal lower esophageal sphincter (LES) pressure. The LES has radial asymmetry, with maximum pressure on the left side. It has been noted that one directional LES pressure, determined using the rapid pull-through (RPT) method, in most patients with severe RE is very low, compared with that in healthy subjects. The aim of this study was to examine whether or not the minimum value of four directional LES pressures could become an index of RE by the RPT method.MethodsThirty patients with severe RE (grade C or D of the Los Angeles classification) were compared with 30 patients with mild RE (grade A or B) and 30 healthy subjects of comparable age and sex. LES pressure was measured by the RPT method, with the subject in the supine position. The catheter was withdrawn manually at a rate of 10 mm/s during suspended respiration at the end-expiratory phase after 5-min rest accommodation. LES pressure, with reference to the intragastric fundic pressure, was recorded by three consecutive RPTs, and 12 LES pressures were obtained for each subject.ResultsMinimum LES pressure, mean LES pressure, and maximum LES pressure were calculated from the 12 LES pressures. Wide overlaps in the mean and maximum LES pressures between healthy subjects and patients with mild or severe RE occurred; however, the overlap of minimum LES pressure between these groups was clearly less than that for the mean and maximum LES pressures. If it is accepted that more than the tenth percentile of the minimum LES pressure in healthy subjects is the cutoff value for healthy subjects, the sensitivity was 93.3% and the specificity for severe RE was 93.3%.ConclusionsThis finding would suggest that the minimum LES pressure determined by the RPT method is an index of severe RE.

Esophageal motility and gastric acid secretion in patients with Barrett's esophagus

Patients with Barretts esophagus (BE) usually have low resting lower esophageal sphincter (LES) pressure, and also have impaired esophageal body motility, with low amplitude and failed peristaltic contractions on swallowing being common. These motor abnormalities contribute to excessive esophageal acid exposure in patients with BE. However, gastric acid secretion is not different between patients with BE and reflux esophagitis.

Effects of transjugular intrahepatic portosystemic shunt (TIPS) on esophageal motor function and gastroesophageal reflux

Abstract: The effects of transjugular intrahepatic portosystemic shunt (TIPS) placement on esophageal motor function and gastroesophageal reflux were investigated in patients with esophageal varices. In six men with esophageal varices, esophageal manometry and upper gastrointestinal endoscopy were performed before and 15–20 days after TIPS placement. Intraesophageal pH monitoring was performed in the four patients with severe esophageal varices (defined as the largest sized varices) following TIPS placement. Findings were compared with those in six healthy men (controls) who underwent esophageal manometry and intraesophageal pH monitoring. The esophageal varices resolved or were reduced after TIPS placement. Resting lower esophageal sphincter (LES) pressures were similar in the study group before and after TIPS placement and in the control subjects. The incidence and progression of esophageal contractions were similar in the study group before and after TIPS placement and in the control subjects. At 3 cm above the LES, the amplitude of esophageal contraction after TIPS placement was significantly higher than that before TIPS placement. At 3 and 8 cm above the LES, the amplitude of esophageal contraction in the control subjects was significantly higher than that in the study group before and after TIPS placement. Esophageal acid exposure time after TIPS placement was similar to that in the controls. TIPS placement is a useful treatment that improves esophageal motor function without the occurrence of pathologic gastroesophageal reflux.