Transient Lower Esophageal Sphincter Relaxations and Gastroesophageal Reflux Episodes in Healthy Subjects and GERD Patients During 24 Hours

Still little is known about the 24-hr pattern of transient lower esophageal sphincter relaxations (TLESRs), particularly in patients with GERD. The aim of our study was to evaluate the 24-hr esophageal and LES motor pattern and esophageal pH and to identify the relationship between TLESRs and gastroesophageal reflux in healthy subjects and in GERD patients. Ten healthy subjects and nine patients with esophagitis (grade I–II) underwent a 24-hr pH manometric recording by means of a portable electronic device. The recording aimed at identifying the temporal relationships between reflux episodes and LES motor events. The GERD patients showed a greater number of either reflux episodes or TLESRs during the 24 hr as compared to controls. While most refluxes occurred during TLESRs in both groups, a small percentage of TLESRs was followed by reflux episodes in healthy people, with only a slight increase in GERD patients. In conclusion, although representing an important motor pattern during gastroesophageal reflux both in healthy subjects and in patients with GERD, TLESR could probably be considered one of the pathophysiologic mechanisms of gastroesophageal reflux more than the primary cause of reflux episodes.     

Pathophysiology of gastroesophageal reflux diseases in Chinese--role of transient lower esophageal sphincter relaxation and esophageal motor dysfunction

BACKGROUND AND AIMS: Transient lower esophageal sphincter relaxation (TLESR) is the major mechanism for gastroesophageal reflux in the Western population. The major reflux mechanism in Chinese patients with GERD has not been studied before. METHODS: Fifty-four patients with GERD and 28 controls underwent stationary baseline manometry and the 24-h ambulatory esophageal pH monitoring. TLESRs were measured before and after an 850 kcal meal in the supine position. Primary peristalsis, secondary peristalsis, and esophageal acid clearance were measured by esophageal manometry. RESULTS: Total time esophageal pH 相似文献   

Excess gastroesophageal reflux in patients with hiatus hernia is caused by mechanisms other than transient LES relaxations

BACKGROUND & AIMS: Esophageal acid exposure is higher in gastroesophageal reflux disease (GERD) patients with hiatus hernia than in those without. We investigated the effect of a sliding hiatus hernia on the mechanisms underlying spontaneous gastroesophageal reflux over 24 hours. METHODS: Twelve GERD patients with and 10 GERD patients without hiatus hernia were studied for 24 hours. Combined esophageal pH and manometric recordings of the pharynx, lower esophageal sphincter (LES), and stomach were performed using a multiple-lumen assembly incorporating a Dent sleeve connected to a portable water-perfused manometric system and a pH glass electrode. RESULTS: Patients with hiatus hernia had greater esophageal acid exposure (7.6% vs. 3.3%; P < 0.01) and more reflux episodes (3.1 vs. 1.8/h; P < 0.001) than those without. LES pressure, the incidence of transient LES relaxations (TLESRs), and the proportion of TLESRs associated with acid reflux were comparable in both groups. Both groups had equal numbers of reflux episodes associated with TLESRs and swallow-associated prolonged LES relaxations. Patients with hiatus hernia had more reflux associated with low LES pressure, swallow-associated normal LES relaxations, and straining during periods with low LES pressure. CONCLUSIONS: The excess reflux in GERD patients with hiatus hernia compared with those without is caused by malfunction of the gastroesophageal barrier during low LES pressure, swallow-associated normal LES relaxations, deep inspiration, and straining.     

The role of transsphincteric pressure and proximal gastric volume in acid reflux before and after fundoplication

BACKGROUND & AIMS: This study was conducted to explore the role of proximal gastric volume and transsphincteric pressure on acid reflux during transient lower esophageal sphincter relaxation (TLESR) in patients with gastroesophageal reflux disease (GERD) both before and after laparoscopic fundoplication. METHODS: Twenty GERD patients were studied before and after fundoplication along with 20 healthy controls. High-resolution manometry and pH recording was performed for 1 hour before and 2 hours following meal ingestion (500 mL/300 kcal). Three-dimensional ultrasonographic images of the stomach were acquired before and every 15 minutes after meal ingestion. RESULTS: Postprandial proximal to total gastric volume distribution ratios were significantly larger in GERD patients before fundoplication (0.57 +/- 0.01; P < .05) and smaller following fundoplication (0.37 +/- 0.01; P < .001) compared with controls (0.46 +/- 0.01). The percentage of TLESRs associated with acid reflux did not relate to proximal gastric volume in any subject group. The transsphincteric pressure profile was different for TLESRs with and without reflux in GERD patients as well as in healthy controls. The pressure gradient across the esophagogastric junction (EGJ) (DeltaEGJp) was greater for TLESRs with acid reflux compared with TLESRs without acid reflux in both GERD patients (11.4 +/- 0.8 vs 8.0 +/- 0.5 mm Hg, respectively; P < .01) and controls (10.6 +/- 0.7 vs 7.1 +/- 0.8 mm Hg, respectively; P < .05). After fundoplication, DeltaEGJp during TLESRs was 7.9 +/- 0.9 mm Hg, and the transsphincteric pressure profile markedly changed. CONCLUSIONS: Although proximal gastric volume plays a key role in eliciting TLESRs, it is not related to the incidence of acid reflux during TLESRs. The transsphincteric pressure gradient is greater in TLESRs associated with acid gastroesophageal reflux.     

Transient lower esophageal sphincter relaxation and the related esophageal motor activities

Transient lower esophageal sphincter (LES) relaxation (TLESR) is defined as LES relaxation without a swallow. TLESRs are observed in both of the normal individuals and the patients with gastroesophageal reflux disorder (GERD). However, TLESR is widely considered as the major mechanism of the GERD. The new equipments such as high resolution manometry and impedance pH study is helped to understand of TLESR and the related esophageal motor activities. The strong longitudinal muscle contraction was observed during development of TLESR. Most of TLESRs are terminated by TLESR related motor events such as primary peristalsis and secondary contractions. The majority of TLESRs are associated with gastroesophageal reflux. Upper esophageal sphincter (UES) contraction is mainly associated with liquid reflux during recumbent position and UES relaxation predominantly related with air reflux during upright position. The frequency of TLESR in GERD patients seems to be not different compared to normal individuals, but the refluxate of GERD patients tend to be more acidic during TLESR.     

Composition of the postprandial refluxate in patients with gastroesophageal reflux disease

OBJECTIVE: It is not known whether the characteristics of the postprandial refluxate in patients with gastroesophageal reflux disease (GERD) differ from those observed in normal subjects. The aim of this study was to characterize the postprandial refluxate in adult patients with GERD using combined intraluminal electrical impedance and pH measurements. METHODS: Postprandial gastroesophageal reflux was assessed in 16 patients with GERD and 15 controls. pH and intraluminal electrical impedance were used to identify acid and nonacid reflux of liquid, mixed (liquid + gas) or gas. RESULTS: Transient lower esophageal sphincter relaxations (TLESRs) and reflux of gastric contents were equally frequent in both groups. However, patients with GERD had more acid reflux [8 (4.7-10.5)/h vs 3.5 (2.6-6)/h, p < 0.05], and normal subjects had more nonacid reflux [5 (4.3-6.7)/h is 3 (1-3.5)/h, p < 0.05]. Gas reflux was less frequent in GERD than in controls (51% vs 68%; p < 0.05). Pure liquid reflux, however, was more frequent (40% vs 26%, p < 0.05) and twice as likely to be acid in GERD. During TLESRs, liquid acid reflux was more frequent in GERD than in controls. CONCLUSIONS: TLESRs and reflux of gastric contents are similarly frequent in patients with GERD and controls. However, patients with GERD have more acid reflux and less nonacid reflux. Differences in the air-liquid composition of the refluxate may contribute to the higher rate of acid reflux observed in these patients.     

Transient Lower Esophageal Sphincter Relaxations and Esophageal Body Muscular Contractile Response in Reflux Esophagitis

In patients with gastroesophageal reflux disease (GERD), transient lower esophageal sphincter relaxations (TLESRs) are more frequently accompanied by acid reflux than in normals. The role of esophageal tone during gastroesophageal reflux events is unknown. We studied the tonic motor activity in the body of the esophagus during TLESRs with and without acid reflux in 11 patients with erosive esophagitis and compared the results with those previously obtained in healthy subjects. Esophageal peristaltic contractions were recorded 13, 8, and 3 cm above a sleeve that measured LES pressure. An intraluminal balloon was inflated 8 cm above the sleeve to induce an esophageal tonic contraction [artificial high pressure zone (HPZ)]. The percentage of TLESRs with acid reflux was significantly higher in patients with esophagitis than in healthy controls (58.3% vs 37.3%, P < 0.05). TLESRs per se were not associated with an inhibition or increase in esophageal body contractility, which, however, changed substantially immediately after reflux. In patients with esophagitis the esophageal body tonic contractility was inhibited in 59.5% of TLESRs vs 36% in controls (P < 0.05). Esophageal contractions during TLESRs traveled down the esophagus in 77% of the instances in patients vs 96.5% in controls (P < 0.05). In conclusion, gastroesophageal reflux during TLESRs was more frequently associated with inhibition of esophageal body tonic contractility in patients with esophagitis than in normals. The different response of the esophageal body to reflux observed in GERD patients may partially contribute to the higher prevalence of reflux during TLESRs in these patients.     

Gastroesophageal reflux and gastric emptying,revisited

Total gastric emptying is delayed in 10% to 33% of adult patients with gastroesophageal reflux disease (GERD), but a strong correlation between duration of gastric emptying and severity of acid reflux or esophagitis has never been proved. Previous studies reported that patients with GERD might have exaggerated postprandial fundus relaxation with retention of food and triggering of transient lower esophageal sphincter relaxations (TLESRs). There is a positive correlation between postprandial fundus relaxation and number of TLESRs and also between proximal gastric emptying and esophageal acid exposure. However, new studies suggest that a high number of TLESRs and reflux events may occur even with accelerated gastric emptying, and prolonged gastric retention might be associated with less rather than more esophageal acid exposure. Using simultaneous gastric emptying and esophageal pH impedance we found that the rate of gastric emptying might determine the acidity and proximal extent of reflux: The slower the emptying, the higher the pH and proximal extent of the refluxate.     

Effects of bronchial obstruction on lower esophageal sphincter motility and gastroesophageal reflux in patients with asthma

The relationship between gastroesophageal reflux and asthma remains unclear. The aim of this study was to analyze the effect of bronchial obstruction on lower esophageal sphincter (LES) motility and reflux in patients with asthma. LES motility and esophageal pH were assessed in eight subjects with intermittent asthma and eight healthy volunteers during three consecutive 30-minute periods: baseline, methacholine-induced bronchospasm, and after inhalation of the beta2-agonist salbutamol. Healthy subjects inhaled 2 mg of methacholine, whereas subjects with asthma inhaled the dose of methacholine causing a 15% fall in FEV(1), as determined by a previous methacholine challenge. LES motility, esophageal pH, and FEV(1) were not significantly different between the three periods in healthy subjects. In patients with asthma, methacholine induced a 21.9 +/- 2.6% decrease in FEV(1) and a concomitant increase in the rate of transient LES relaxation (TLESR) and reflux episodes. Inhalation of salbutamol decreased the rate of TLESRs but not the number of reflux episodes. We conclude that in patients with asthma, methacholine-induced bronchospasm increases the rate of TLESR and the number of reflux episodes. These results support the belief that, in asthma, bronchial obstruction may be responsible for reflux or may aggravate reflux through a mechanism that remains to be further clarified.     

Randomized,double-blind,placebo-controlled crossover trial of pirenzepine in patients with gastroesophageal reflux

A muscarinic receptor subtype 1 (M1) antagonist, pirenzepine, recently has been shown to be relatively free of the usual anticholinergic side effects on esophageal smooth muscle and thus has been implicated for the treatment of gastroesophageal reflux disease (GERD). However, the effect of pirenzepine on GERD remains to be defined. Thirteen patients who demonstrated GERD in a baseline 24-hr ambulatory intraesophageal pH monitoring study were randomized in a double-blind crossover fashion to receive pirenzepine and placebo. An ambulatory 24-hr intraesophageal pH monitor was used to assess reduction in reflux (esophageal pH less than 4.0) with respect to position (upright vs supine), to total number of reflux episodes, and to episodes greater than 5 min. A significant effect for pirenzepine was seen for episodes greater than 5 min (t = 2.61, P = 0.023) and a trend towards significance was seen for total (upright and supine positions combined) percent time of reflux (t = 2.13, P = 0.055). Although not statistically significant, pirenzepine consistently showed greater reduction in all parameters of reflux tested. A greater reduction in percent time of reflux in supine vs upright positions (pirenzepine: 58.9% vs 21.4%; placebo: 43.6% vs 7.3%) may be clinically important in prevention of esophageal injury due to reflux in the recumbent position. Pirenzepine may provide a unique alternative for some GERD patients who may be refractory to other therapies of GERD.     

Provocation of transient lower esophageal sphincter relaxations by gastric distension with air

OBJECTIVES: Transient lower esophageal sphincter relaxations (TLESRs) are the major mechanism permitting not only gastroesophageal reflux but also venting of air from the stomach. Triggering of TLESRs is provoked by gastric distension. Antireflux surgery is associated with impaired ability to belch. It is not known whether a reduced capacity to belch results from postoperative reduction in TLESRs. METHODS: We studied the occurrence of TLESRs, common cavities (indicator for gas gastroesophageal reflux), and belching after standardized acute gastric distension by air insufflation (750 ml). Control subjects (n = 10), patients with gastroesophageal reflux disease (GERD) (n = 22), and patients after fundoplication (n = 24) were studied. LES and esophageal motilities were recorded with perfusion manometry. RESULTS: Gastric distension with air significantly (p < 0.05) increased TLESR frequency in controls (1.6+/-0.3 to 3.5+/-1.0 per 20 min), GERD patients (1.2+/-0.3 to 3.1+/-0.5 per 20 min), and patients after fundoplication (0.5+/-0.1 to 1.8+/-0.6 per 20 min). Postfundoplication the number of TLESRs was significantly reduced (p < 0.05) both under fasting conditions and after air insufflation. The number of common cavities and belches after gastric air distension also was significantly reduced (p < 0.05) after fundoplication: 2.3+/-0.6 versus 4.7+/-0.4 in controls and 4.1+/-0.4 in GERD patients. About half of the common cavities occurred during TLESRs, and half during other mechanisms. An impaired ability to belch in daily life correlated with an impaired belching response during the test. An impaired ability to belch occurred only in patients with complete fundoplication and not in patients with partial fundoplication and was associated with a reduced number of common cavities after gastric air insufflation. CONCLUSIONS: Short-lasting gastric air distension 1) provokes TLESRs but does not differentiate GERD patients from controls, 2) reveals impaired belching capacity in patients after complete fundoplication, and 3) shows that common cavities do not exclusively occur during TLESRs.     

Effect of sodium valproate on esophageal motility in healthy subjects and patients with gastroesophageal reflux

BACKGROUND: There is experimental evidence to show that upper gastrointestinal tract motility is influenced by a GABAergic mechanism. Sodium valproate acts as a GABA agonist, and has been proven to affect the human internal anal sphincter. The aim of this study was to evaluate any possible effect of sodium valproate on esophageal motility in healthy subjects and patients with gastroesophageal reflux disease (GERD). METHODS: Ten healthy volunteers (4 M, 6 F; age range: 20-61 years) and 12 patients (4 M, 8 F; age range: 25-70 years) with GERD were included in the study. Standard esophageal manometry and ambulatory 24-h esophageal pH monitoring were performed before and 5 days after oral administration of sodium valproate (400 mg four times per day). Main measurements included a) lower esophageal sphincter (LES) resting pressure and amplitude and duration of peristalsis at 5, 10 and 15 cm proximal to LES, and b) percentage of time with esophageal pH <4 and number of reflux episodes. RESULTS: Sodium valproate (i) significantly increased LES resting pressure in both groups (P<0.05), without affecting either the LES postdeglutition relaxation or any of the parameters of the esophageal peristaltic activity, (ii) significantly reduced the number of reflux episodes at the postprandial period in both healthy subjects (P=0.02) and reflux patients without hiatal hernia (P=0.04) and (iii) the time percentage with esophageal pH <4 at the postprandial period in reflux patients (P=0.01). CONCLUSIONS: Sodium valproate increases normal and reduced tonic activity of the human LES and reduces the number of reflux episodes in health and GERD. This action could be attributed to a central GABAergic mechanism.     

Fasting and postprandial mechanisms of gastroesophageal reflux in children with gastroesophageal reflux disease

In order to define the mechanisms of gastroesophageal reflux (GER) in children, we performed simultaneous intraluminal, esophageal motility and pH studies in 24 children with symptomatic reflux and abnormal prolonged pH probe study, ten (group A) without endoscopic and histologic esophagitis, 14 (group B) with endoscopic and histologic esophagitis. Median (ranges) age (years) was 5.0 (6 months-10 years) and 3.0 (6 months-12 years), respectively. Recordings were done for 1 hr before and 1 hr after feeding apple juice (15 ml/kg; pH 4.0). All episodes of GER in group A patients and 77.1% in group B patients were accounted for by abrupt transient lower esophageal sphincter (LES) relaxation (TLESR); 22.9% of reflux events in group B patients occurred during gradual drifts of LES pressure (LESP) to undetectable levels. Esophageal refluxate exposure (mean percentage time with esophageal pH<4.0) the rate of TLESR (number of episodes/hr), and the percentage of TLESRs associated with reflux significantly increased in the fed period both in group A (18.5±5.4%, 6.2±2.65, 87.1%) and in group B (29.7±6.5 7.8±3.05, 84.9%) as compared to the fasting state (group A: 10.8±3.9, 3.9±3.17, 46.1%; group B: 16.1±2.6, 4.14±3.06, 55.17%) (p<0.01). The rate of LESP drifts (number of episodes/hr) was also significantly higher postprandially (4.85±1.24 vs 1.8±0.9,p<0.01); furthermore there was a postfeeding increase of the LESP drift percentage associated with reflux (79.41% vs 46.15%,p<0.01). Residual pressure of TLESRs associated with reflux was significantly lower than that of TLESRs without GER in both groups of patients, during fasting (group A:p<0.01; group B:p<0.05) and fed state (p<0.05), whereas duration of relaxation and LESP in the 1-min period before each TLESR did not discriminate TLESRs associated with reflux from those without reflux. In children with GER disease, TLESR is the most common mechanism of reflux, but gradual LESP drift is associated with more severe disease; the postprandial increase in the esophageal acid exposure is mainly due to increased rate of TLESRs and LESP drifts; degree of sphincter inhibition during TLESRs is a critical factor for the induction of reflux.Presented in part at the 91st Annual Meeting of the American Gastroenterological Association, San Antonio, Texas, May 12–18, 1990.     

Transient lower esophageal sphincter relaxations are no more frequent in patients with gastroesophageal reflux disease than in asymptomatic volunteers

OBJECTIVES: Studies of the relative frequency of transient lower esophageal sphincter relaxations (TLESRs) in patients with gastroesophageal reflux disease and asymptomatic controls have revealed conflicting data. We have therefore studied the frequency of TLESRs and the frequency and mechanisms of acid reflux episodes in patients with gastroesophageal reflux disease and age- and sex-matched asymptomatic controls using standardized criteria. METHODS: Ten patients with symptomatic gastroesophageal reflux disease (four male, aged 50 [30-59] yr) and 10 asymptomatic matched volunteers (four male, aged 50 [32-59] yr) were studied. Esophageal, lower esophageal sphincter, and gastric manometric and esophageal pH readings were recorded for 1 h before and 1 h after a 200-kcal, 150 ml long-chain triglyceride meal. RESULTS: TLESR frequency increased after the meal in both volunteers (median 0 [range = 0-3] to 3 [0-8] per hour,p < 0.01) and patients (1 [0-6] to 2.5 [0-9] per hour, p = 0.08). There was no significant difference in the frequency of TLESRs between volunteers and patients. TLESRs were more likely to be associated with acid reflux in patients (65% vs 37%, p = 0.03), whereas volunteers were more likely to reflux gas or liquid without acid (30% vs 3.0%, p = 0.01). CONCLUSIONS: TLESRs are no more frequent in patients with gastroesophageal reflux disease than age- and sex-matched asymptomatic volunteers. However, when TLESRs occur in patients, they are twice as likely to be associated with acid reflux.     

Pathophysiology and pharmacological treatment of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is one of the most common diagnoses in a gastroenterologist's practice. Gastroesophageal reflux describes the retrograde movement of gastric contents through the lower esophageal sphincter (LES) to the esophagus. It is a common, normal phenomenon which may occur with or without accompanying symptoms. Symptoms associated with GERD include heartburn, acid regurgitation, noncardiac chest pain, dysphagia, globus pharyngitis, chronic cough, asthma, hoarseness, laryngitis, chronic sinusitis and dental erosions. The introduction of fiberoptic instruments and ambulatory devices for continuous monitoring of esophageal pH (24-hour pH monitoring) has led to great improvement in the ability to diagnose reflux disease and reflux-associated complications. The development of pathological reflux and GERD can be attributed to many factors. Pathophysiology of GERD includes incompetent LES because of a decreased LES pressure, transient lower esophageal sphincter relaxations (TLESRs) and deficient or delayed esophageal acid clearance. Uncomplicated GER may be treated by modification of life style and eating habits in an early stage of GERD. The various agents currently used for treatment of GERD include mucoprotective substances, antacids, H(2) blockers, prokinetics and proton pump inhibitors. Although these drugs are effective, they do not necessarily influence the underlying causes of the disease by improving the esophageal clearance, increasing the LESP or reducing the frequency of TLESRs. The following article gives an overview regarding current concepts of the pathophysiology and pharmacological treatment of GERD.     

The role of excessive esophageal acid exposure in patients with gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD), especially reflux esophagitis (RE), is characterized by excessive esophageal acid exposure. Transient lower esophageal sphincter (LES) relaxation is the major mechanism of acid reflux episodes in both healthy subjects (HS) and patients with GERD. In the sitting position, where acid reflux episodes often occur, there is no difference in the frequency of transient LES relaxations between these two groups; however, in patients with GERD, at 5 cm above the LES, the proportion of acid reflux episodes during transient LES relaxations is significantly greater than in the HS group. This difference is considered to be one of the causes of excessive esophageal acid exposure in patients with GERD, but its cause is still unclear. A recent study, which investigated the proportion of acid reflux episodes during transient LES relaxations at 2 and 7 cm above the LES, showed that there was no difference at 2 cm above the LES between HS and patients with RE, but at 7 cm they were significantly greater in patients with RE than in HS. Evaluation of acid reflux at 2 cm above the LES is difficult to measure, but the proximal extent of refluxate could be one of the important factors of excessive acid esophageal exposure in patients with RE. Ineffective esophageal motility, found in patients with moderate to severe RE, impairs esophageal bolus clearance of acid, therefore both the proximal extent of refluxate and the delay of esophageal bolus clearance of acid could be major causes of excessive esophageal acid exposure. Hiatus hernia also causes acid reflux, due to its association with hypotensive LES, and also impairs esophageal bolus clearance of acid.     

Effect of laparoscopic partial fundoplication on reflux mechanisms

OBJECTIVES: Transient lower esophageal sphincter relaxations (TLESRs) are the main mechanism causing gastroesophageal reflux. Since 1994 we have performed laparoscopic partial instead of complete fundoplication as standard surgical treatment for therapy resistant reflux disease to minimize postoperative dysphagia. To better understand the management of gastroesophageal reflux, we conducted a prospective study of the effects of laparoscopic partial fundoplication on TLESRs and other reflux mechanisms. METHODS: From 1994 to 1999, 65 patients underwent laparoscopic partial fundoplication (180-200 degrees) and 28 of these patients (16 female, 12 male, mean age 43 +/- 2 yr [range, 26-66 yr]) agreed to participate in this prospective study on reflux mechanisms. Before and 6 months after surgery, all patients were evaluated by simultaneous recording of pH and lower esophageal sphincter characteristics, using sleeve manometry. RESULTS: After partial fundoplication basal LES pressure increased significantly (p < 0.05), from 14.3 +/- 1.2 mm Hg to 17.8 +/- 1 mm Hg. Partial fundoplication significantly (p < 0.05) decreased the number of TLESRs, from 3.4 +/- 0.8 to 1.6 +/- 0.3 per hour in the fasting period, and from 4.7 +/- 0.5 to 1.9 +/- 0.3 per hour postprandially. The percentage of TLESRs associated with reflux also decreased significantly (p < 0.05), from 45 +/- 7% to 27 +/- 6% after operation. The number of reflux episodes decreased significantly (p < 0.05), from 4.1 +/- 0.7 to 1.3 +/- 0.3 per hour postoperatively. The majority of these episodes were associated with TLESRs: 57% and 46%, pre- and postoperatively, respectively. CONCLUSIONS: Laparoscopic partial fundoplication significantly increased fasting and postprandial LES pressure and significantly decreased TLESR frequency. This resulted in a significant reduction in esophageal acid exposure, with preservation of postprandial LES characteristics.     

Effect of different recumbent positions on postprandial gastroesophageal reflux in normal subjects

OBJECTIVE: Gastroesophageal reflux (GER) is increased in the right compared to the left recumbent position. Esophageal acid exposure is related to the acidity at the cardia, but the effect of body position on the acidity at the cardia has not yet been investigated. We aimed to investigate the mechanisms underlying increased esophageal acid exposure in the right recumbent position. METHODS: On 2 separate days a 4-h combined esophageal and lower esophageal sphincter (LES) manometry and pH recording of esophagus, gastric cardia, and corpus was performed in the right and left recumbent position after a high fat meal in 10 healthy subjects. RESULTS: In the right recumbent position a prolonged esophageal acid exposure (7.0% vs 2.0%, p < 0.03), a higher incidence of reflux episodes (3.8 vs 0.9/h, p < 0.03), more transient LES relaxations (TLESRs) (6.5 vs 3.2/h, p < 0.03), and higher percentage TLESRs associated with reflux (57.0% vs 22.4% p < 0.03) was recorded than in the left supine position. Acidity at gastric cardia and corpus was not affected by body position. CONCLUSIONS: Increased esophageal acid exposure in the right recumbent position relative to the left recumbent position is the result of a higher incidence of GER episodes caused by an increased incidence of TLESRs and higher percentage of TLESRs associated with GER. Body position does not affect the acidity at the gastric cardia and corpus.     

胃食管反流病与特发性肺间质纤维化的关系

目的 明确特发性肺间质纤维化(IPIF)患者胃食管反流病(GERD)的患病率,探讨GERD与IPIF的关系.方法 对2006年12月至2008年1月在首都医科大学附属北京朝阳医院呼吸科住院确诊的24例IPIF患者进行24 h食管pH监测和食管测压,同期住院的23例非IPIF的弥漫性实质性肺疾病患者作为对照.比较两组患者GERD症状、病理性食管酸暴露及无效食管动力(IEM)的发生率.结果 (1)66.7%(16/24)的IPIF患者存在病理性食管酸暴露,明显高于对照组的26.10k(6/23),P<0.05;(2)在具有病理性酸暴露的IPIF(GERD-IPIF)患者中,87.5%(14/16)存在夜间酸暴露事件;(3)典型GERD症状在GERD-IPIF患者中的发生率只有37.5%(6/16);(4)IPIF组和非IPIF组患者IEM发生率相似,分别为42.9%(9/21)和39.1%(9/23),P>0.05.结论 在IPIF患者中GERD患病率较高,但多数患者没有典型GERD症状,IPIF患者应该进行24 h食管pH监测筛查GERD.     

Effect of l-NMMA on Postprandial Transient Lower Esophageal Sphincter Relaxations in Healthy Volunteers

In a previous study we showed that nitric oxide (NO) synthesis inhibition by N ^G-monomethyl-l-arginine (l-NMMA) reduced the number of transient lower esophageal sphincter relaxations (TLESRs) triggered by gastric balloon distention. The role of NO in postprandial TLESRs and gastroesophageal reflux, however, is unknown. Therefore, we studied the effect of l-NMMA on meal-induced TLESRs and reflux episodes with simultaneous recording of esophageal peristalsis, intraesophageal and intragastric pH, and gastric emptying in healthy volunteers. Ingestion of a solid meal resulted in an increase in TLESRs [8.5 (6.3–11.0) 60 min] which was significantly inhibited by l-NMMA [6.0 (4.0–8.8) 60 min, P < 0.05]. In addition, the total number of reflux episodes was reduced. l-NMMA had no effect on intragastric meal distribution and gastric emptying, but attenuated the postprandial increase in intragastric pH. These results confirm the involvement of NO in the neurocircuitry underlying the triggering of TLESRs. The reduction in reflux by l-NMMA has to be confirmed in patients with gastroesophageal reflux disease. NO may be involved in the regulation of gastric acid secretion.