Duration Of Lower Esophageal Sphincter Relaxation Research Articles

Evaluation of Esophageal Functions by Manometry in Iron Deficiency Anemia Patients.

BackgroundThe aim of this study was to investigate whether any esophageal motor dysfunction exists in patients with iron deficiency anemia (IDA).MethodsThe study included 39 patients (34 women, mean age: 44.17 ± 14.21 years) who met WHO diagnostic criteria for IDA. An additional 30 functional dyspepsia patients were also included as a control group. Esophageal motility testing was performed; esophagus contraction amplitude, peak velocity, contraction time, lower esophageal sphincter (LES) resting pressure, LES relaxation, and LES relaxation duration were assessed.ResultsA majority (76.4%) of patients had at least one IDA symptom, such as reflux, chest pain, or dysphagia. Manometric findings in IDA patients vs. controls were as follows: mean LES resting pressure (mm Hg): 25.41 ± 11.67 vs. 19.96 ± 6.58 (P = 0.025); mean esophageal contraction amplitude (mm Hg): 61.61 ± 24.21 vs. 63.23 ± 18.86 (P = 0.764); mean LES relaxation duration (s, x ± SD): 5.33 ± 1.61 vs. 8.75 ± 1.86 (P = 0.000); mean LES relaxation (%): 93.30 ± 9.88 vs. 95.53 ± 5.81 (P = 0.278); mean peak velocity (cm/s): 12.67 ± 37.95 vs. 3.50 ± 1.63 (P = 0.191). Esophageal dysmotility was found in 11 (28.2%) IDA patients. Non-specific esophageal motor disorder was found in three patients, hypomotility of the esophagus was found in three patients, achalasia was found in two patients, hypertensive LES was found in two patients, and hypotensive LES was found in one patient.ConclusionLES resting pressure was higher and LES relaxation duration was shorter in patients with IDA. Esophageal dysmotility was present in 28.2% of the patients with IDA A little more than half of patients had dysphagia symptoms. IDA may contribute to esophageal motility dysfunction and esophageal symptoms.

Manometric assessment of esophageal motor function in patients with primary biliary cirrhosis

Introduction/aimPrimary biliary cirrhosis is associated with other autoimmune diseases including Sjögren's syndrome, and scleroderma. Esophageal dysmotility is well known in scleroderma, and Sjögren's syndrome. The aim of this study is to investigate whether any esophageal motor dysfunction exists in patients with primary biliary cirrhosis. MethodThe study was performed in 37 patients (36 women, mean age: 56.29±10.01years) who met diagnostic criteria for primary biliary cirrhosis. Thirty-seven functional dyspepsia patients, were also included as a control group. Patients entering the study were asked to complete a symptom questionnaire. Distal esophageal contraction amplitude, and lower esophageal sphincter resting pressure were assessed. ResultsManometric findings in primary biliary cirrhosis patients vs. controls were as follows: Median lower esophageal sphincter resting pressure (mmHg): (24 vs 20, p=0.033); median esophageal contraction amplitude (mmHg): (71 vs 56, p=0.050); mean lower esophageal sphincter relaxation duration (sc, x±SD): (6.10±1.18 vs 8.29±1.92, p<0.001); and median lower esophageal sphincter relaxation (%) (96 vs 98, p=0.019); respectively. No significant differences were evident in median peak velocity (sc) (3.20 vs 3.02, p=0.778) between patients with primary biliary cirrhosis and the functional dyspepsia patients. Esophageal dysmotility was found in 17 (45.9%) primary biliary cirrhosis patients (non-specific esophageal motor disorder in ten patients, hypomotility of esophagus in five patients, nutcracker esophagus in one patient and hypertensive lower esophageal sphincter in one patient). ConclusionEsophageal dysmotility was detected in 45.9% of patients. The study suggests that subclinic esophageal dysmotility is frequent in patients with primary biliary cirrhosis.

Effect of buspirone, a 5-HT1A receptor agonist, on esophageal motility in healthy volunteers

There are limited data concerning the effects of 5-HT(1A) receptor activation on esophageal motility. Sumatriptan, a 5-HT(1A) receptor agonist, was recently reported to enhance esophageal peristalsis after intravenous administration. Buspirone, an orally available 5-HT(1A) receptor agonist, was shown to modulate gastroduodenal motor function. Our aim was to evaluate the effect of buspirone on esophageal motility of healthy volunteers. On two separate visits, 20 healthy volunteers aged 21-29 years (nine women) underwent esophageal manometry before and 10, 30, and 60 minutes after the administration of buspirone 20-mg or placebo capsule, according to a double-blind crossover design. At each time point, we compared buspirone and placebo effects on: resting pressure of the lower esophageal sphincter (LES); residual pressure and duration of LES relaxation; amplitude, duration, and onset velocity of esophageal body contractions, during 10 swallows of 5 mL of water. Significant analysis of variance differences (P < 0.05) are presented as mean ± standard deviation. Buspirone significantly increased mean distal esophageal wave amplitude (151 vs. 87 mmHg, P < 0.05) and duration (6.1 vs. 4.2 seconds, P < 0.05). Similarly, buspirone significantly increased mean LES resting pressure (26 vs. 21 mmHg, P < 0.05) and mean residual LES pressure (7.9 vs. 2 mmHg, P < 0.05), whereas reduced mean LES relaxation duration (7.2 vs. 8.0 seconds, P < 0.05) and mean distal onset velocity (7.6 vs. 14.7 cm/second, P < 0.05). Buspirone enhances esophageal peristalsis and LES function in healthy volunteers. Further study is warranted on the effects of buspirone on esophageal function and symptoms in patients with ineffective esophageal motility.

Factors influencing lower esophageal sphincter relaxation after deglutition.

To study the relationship between upper esophageal sphincter (UES) relaxation, peristaltic pressure and lower esophageal sphincter (LES) relaxation following deglutition in non-dysphagic subjects. Ten non-dysphagic adult subjects had a high-resolution manometry probe passed transnasally and positioned to cover the UES, the esophageal body and the LES. Ten water swallows in each subject were analyzed for time lag between UES relaxation and LES relaxation, LES pressure at time of UES relaxation, duration of LES relaxation, the distance between the transition level (TL) and the LES, time in seconds that the peristaltic wave was before (negative value) or after the TL when the LES became relaxed, and the maximal peristaltic pressure in the body of the esophagus. Relaxation of the LES occurred on average 3.5 s after the bolus had passed the UES and in most cases when the peristaltic wave front had reached the TL. The LES remained relaxed until the peristaltic wave faded away above the LES. LES relaxation seemed to be caused by the peristaltic wave pushing the bolus from behind against the LES gate.

Persistent Reflux Symptoms in the Proton Pump Inhibitor Era: The Changing Face of Gastroesophageal Reflux Disease

Given the widespread use of potent acid suppressive therapies and primary caregivers’ increasing comfort with prescribing these medications at high doses, the patient population presenting to gastroenterologists for symptoms of gastroesophageal reflux disease (GERD) has changed. Whereas previous consultation often revolved around the control of erosive disease and other mucosal manifestations of GERD, and terminated with the prescription of proton pump inhibitor (PPI) therapy, gastroenterologists often now only enter the scene after failure of PPI therapy, for symptoms either resistant or only partially responsive to these medications. Because of the high proportion of subjects with esophagitis who are healed with PPI, 1,2 upper endoscopy of such individuals is low yield, 3 with only a small minority demonstrating erosive disease. The care of such patients is challenging. High-quality evidence supporting useful diagnostic testing or alternative effective therapies is largely lacking. However, the number of subjects with GERD symptoms incompletely or nonresponsive to PPI therapies is high, and their utilization of healthcare resources is substantial. The purpose of this mini-review is to examine the definition and epidemiology of esophageal GERD symptoms incompletely responsive to PPI therapy, the potential pathophysiologic mechanisms behind these symptoms, the differential diagnosis and evaluation of such patients, and current and developing therapeutic options.

Esophageal motor function in Familial Mediterranean Fever: A prospective evaluation of motility in 31 patients

Background The aims of this study were to evaluate esophageal motor function in patients with Familial Mediterranean Fever (FMF) who had upper gastrointestinal symptoms and to compare esophageal motor function between FMF patients who developed amyloidosis and patients without amyloidosis. Methods 31 FMF patients with dyspeptic symptoms and 31 healthy age-matched individuals were included in the study. Endoscopic examination and esophageal motility testing were performed. Results Esophageal motor abnormalities were detected in 25.8% (8/31) of these patients [incomplete Lower esophageal sphincter (LES) relaxation: n = 4, esophageal hypomotility: n = 2, and hypotensive LES: n = 2]. Median LES relaxation (%) (min–max) was significantly lower in patients with FMF compared to control group 94% (54–100) vs. 98% (80–100), p = 0.019 respectively). However, mean LES pressure (mmHg) (19.5 ± 8.9 vs. 19.7 ± 5.6, p = 0.813), duration of LES relaxation (s) (7.9 ± 1.7 vs. 8.7 ± 1.7, p = 0.068), contraction amplitude of esophageal body (mmHg) (60.4 ± 23.3 vs. 58.2 ± 19.7, p = 0.691) and median (min–max) peak velocity (s) [3.1(− 1.43–50.3) vs. 3.1 (0.9–8.7), p = 0.435] were similar in patients with FMF compared to control group. There were no significant differences with regard to LES pressure, LES relaxation, LES relaxation duration, contraction amplitude (mmHg) and peak velocity (sc) among patients with FMF and amyloidosis, amyloidosis negative FMF patients and healthy controls. Conclusions Abnormal esophageal manometric findings can be observed at least in a subgroup of patients with FMF regardless of amyloid status. Investigation of esophageal motor function in patients with FMF who exhibit unexplained upper gastrointestinal symptoms between attacks may be a helpful tool in order to delineate esophageal motor dysfunction.

The Effect of an Effortful Swallow on the Normal Adult Esophagus

The effect of an effortful swallow on the healthy adult esophagus was investigated using concurrent oral and esophageal manometry (water perfusion system) on ten normal adults (5 males and 5 females, 20-35 years old) while swallowing 5-ml boluses of water. The effects of gender, swallow condition (effortful versus noneffortful swallows), and sensor site within the oral cavity, esophageal body, and lower esophageal sphincter (LES) were examined relative to amplitude, duration, and velocity of esophageal body contractions, LES residual pressure, and LES relaxation duration. The results of this study provide novel evidence that an effortful oropharyngeal swallow has an effect on the esophageal phase of swallowing. Specifically, effortful swallowing resulted in significantly increased peristaltic amplitudes within the distal smooth muscle region of the esophagus, without affecting the more proximal regions containing striated muscle fibers. The findings pertaining to the LES are inconclusive and require further exploration using methods that permit more reliable measurements of LES function. The results of this study hold tremendous clinical potential for esophageal disorders that result in abnormally low peristaltic pressures in the distal esophageal body, such as achalasia, scleroderma, and ineffective esophageal motility. However, additional studies are necessary to both replicate and extend the present findings, preferably using a solid-state manometric system in conjunction with bolus flow testing on both normal and disordered populations, to fully characterize the effects of an effortful swallow on the esophagus.

The impact of continuous positive airway pressure on the lower esophageal sphincter

The lower esophageal sphincter (LES) is the primary barrier to gastroesophageal reflux. Reflux is associated with periods of LES relaxation, as occurs during swallowing. Continuous positive airway pressure (CPAP) has been shown to reduce reflux in individuals with and without sleep apnea, by an unknown mechanism. The aim of this study was to determine the effect of CPAP on swallow-induced LES relaxation. Measurements were made in 10 healthy, awake, supine individuals. Esophageal (Pes), LES (Ples), gastric (Pg), and barrier pressure to reflux (Pb = Ples - Pg) were recorded using a sleeve catheter during five swallows of 5 ml of water. This was repeated at four levels of CPAP (0, 5, 10, and 15 cmH(2)O). Pressures were measured during quiet breathing and during the LES relaxation associated with a swallow. Duration of LES relaxation was also recorded. During quiet breathing, CPAP significantly increased end-expiratory Pes, Ples, Pg, and Pb (P < 0.05). The increase in Pb was due to a disproportionate increase in Ples compared with Pg (P < 0.05). During a swallow, CPAP increased nadir Ples, Pg, and Pb and decreased the duration of LES relaxation (4.1 s with 0-cmH(2)O CPAP to 1.6 s on 15-cmH(2)O CPAP, P < 0.001). Pb increased with CPAP by virtue of a disproportionate increase in Ples compared with Pg. This may be due to either reflex activation of LES smooth muscle, or nonspecific transmission of pressure to the LES. The findings suggest CPAP may make the LES less susceptible to reflux by increasing Pb and decreasing the duration of LES relaxation.

Axial stretch: a novel mechanism of the lower esophageal sphincter relaxation

Swallow and esophageal distension-induced relaxations of the lower esophageal sphincter (LES) are associated with an orad movement of the LES because of a concurrent esophageal longitudinal muscle contraction. We hypothesized that the esophageal longitudinal muscle contraction induces a cranially directed mechanical stretch on the LES and therefore studied the effects of a mechanical stretch on the LES pressure. In adult opossums, a silicon tube was placed via mouth into the esophagus and laparotomy was performed. Two needles with silk sutures were passed, 90 degrees apart, through the esophageal walls and silicon tube, 2 cm above the LES. The tube was withdrawn, and one end of each of the four sutures was anchored to the esophageal wall and the other end exited through the mouth to exert graded cranially directed stretch on the LES by using pulley and weights. A cranially directed stretch caused LES relaxation, and with the cessation of stretch there was recovery of the LES pressure. The degree an d duration of LES relaxation increased with the weight and the duration of stretch, respectively. The mean LES relaxation in all animals was 77.7 +/- 4.7%. The required weight to induce maximal LES relaxation differed in animals (714 +/- 348 g). N(G)-nitro-L-arginine, a nitric oxide inhibitor, blocked the axial stretch-induced LES relaxation almost completely (from 78 to 19%). Our data support the presence of an axial stretch-activated inhibitory mechanism in the LES. The role of axial stretch in the LES relaxation induced by swallow and esophageal distension requires further investigation.

‘Functional heartburn’: symptom for achalasia or hypertensive lower oesophageal sphincter?

Sirs, With interest we read the article by Frazzoni et al.1 entitled ‘Pathophysiological characteristics of patients with non-erosive reflux disease differ from those of patients with functional heartburn’ which is published in the current issue of Alimentary Pharmacology and Therapeutics. The study adds important information concerning the pathophysiology underlying gastro-oesophageal reflux disease (GERD).2 Based on data obtained by symptoms (i.e. heartburn, acid regurgitation and chest pain) and upper gastrointestinal (GI) function testing – manometry [lower oesophageal sphincter (LES) resting pressure, oesophageal amplitude], 24 h pH-testing non-erosive GERD and functional heartburn may in fact be a different entities.1 However, in their paper the authors do not provide information on wet swallow induced LES relaxation and duration of LES relaxation.3 In addition, it is not clarified if patients with functional heartburn did have episodes of dysphagia. Thus the reader is not able to exclude if ‘functional heartburn’ may, at least in some patients, be because of functional disorders such as achalasia4 or hypertensive LES.3 We think that exclusion of such disorders is of major importance and it may accurately help to define those patients having ‘functional heartburn’.

Esophageal contractions and oropharyngeal and esophageal transits in patients with iron deficiency anemia

Objective Patients with iron deficiency may have reduced power of the pharyngeal muscle for bolus propulsion into the esophagus. We hypothesized that esophageal muscle is similarly impaired. Methods We studied the oropharyngeal and esophageal transits and esophageal motility of 12 patients (11 women) aged 31–50 yr (median 36 yr) with iron deficiency anemia (serum iron less than 40 μg/dl) and 17 normal volunteers (16 women) aged 26–52 yr (median 37 yr) with serum iron greater than 60 μg/dl. The esophageal motility was studied by the manometric method, with continuous perfusion and 10 swallows of a 2-ml bolus of water alternated with 10 swallows of a 7-ml bolus; and the oropharyngeal and esophageal transits were studied by scintigraphy, with swallows of a 10-ml bolus for the study of oropharyngeal transit and of a 10-ml bolus for the study of esophageal transit. Motility and transit were studied in the supine position. Results The amplitude, duration and area under the curve of contractions were lower in patients than in volunteers. There were no differences in peristaltic contraction velocity, lower esophageal sphincter pressure, and lower esophageal sphincter relaxation duration. There was no difference in oropharyngeal transit. In the esophagus the transit was slower in patients than in volunteers. The time needed by the scintigraphic activity to reach a peak in the proximal esophagus was longer in patients than in volunteers. Conclusions Iron deficiency may decrease esophageal contractions and impair esophageal transit.

Esophageal swallowing phase assessed by audiosignal recording: relationship with manometry in gastroesophageal reflux disease patients.

The acoustic technique has been used for pharyngeal exploration but to date no such technique has been devised to assess esophageal motility. The aim of this study was to demonstrate that displacement through the esophagus can be quantified using this method in healthy subjects and in patients with gastroesophageal reflux. Concurrent manometric and acoustic recordings were also performed in the patients. Fifteen controls (38.5 +/- 13 years old) and 10 patients (34.9 +/- 6 years old) were included. All were recorded during wet and dry swallow sequences with microphones placed below the cricoid cartilage and on the xiphoid appendix. Standard manometry was performed for lower esophageal sphincter (LES) exploration. For the acoustic technique, the frequency of xiphoid signals (FX), esophageal transit time (ETT), duration of xiphoid sound (SD), and for the manometric study, the duration of LES relaxation (RD) were recorded and mean values were calculated (FXm), (ETTm), (SDm), (RDm). FXm for wet (94 vs 81.6%) and dry swallows (86 vs 66.6%) decreased in patients. ETTm was significantly higher (P < 0.01) for wet than for dry swallows (5.6 +/- 0.9 vs 5.2 +/- 1.2 sec) for controls but not for patients. ETTm was significantly higher for patients for wet (7.2 +/- 2.1 sec) and for dry swallows (6.5 +/- 2.3 sec) than for controls and SDm was lower. Xiphoid sound appeared in the second half of LES relaxation. Our noninvasive acoustic technique is simple and reproducible. It is well correlated with manometry, and it allows characterization of the displacement of the bolus through the esophagus and the LES. The technique could be used alone to determine appropriate pharmacological and surgical treatments for esophageal motility disorders.

Lower esophageal sphincter relaxation characteristics using a sleeve sensor in clinical manometry

Objective: We undertook this study to determine the characteristics of swallow-induced lower esophageal sphincter (LES) relaxation in the setting of clinical manometry using a standardized methodology. Methods: We reviewed 170 manometric recordings performed using a perfused manometric assembly with a sleeve sensor and a computer polygraph. Patients were categorized as patient controls, gastroesophageal reflux disease (GERD), diffuse esophageal spasm (DES), or achalasia. Tracing were semiautomatically analyzed for basal LES pressure, LES pressure during deglutitive relaxation (relaxation LES pressure), duration of LES relaxation, timing of LES relaxation, and the success rate of primary peristalsis. Results: Forty-six patient controls, 93 with GERD, five with DES, and 26 with achalasia were identified. GERD and achalasia patients had lower or higher basal LES pressures than patient controls, respectively. Compared with patient controls, achalasia patients had higher relaxation LES pressures, lower percent LES relaxation, and shorter durations of LES relaxation. The best single measure for distinguishing achalasia was the relaxation LES pressure; using the 95th percentile value of patient controls (12 mm Hg) as the upper limit of normal, its sensitivity and positive predictive value for the diagnosis of achalasia were 92% and 88%, respectively. Coupled with the finding of aperistalsis, a relaxation LES pressure ≥10 mm Hg achieved 100% sensitivity and positive predictive value among these patients. Conclusions: Sleeve sensor recording is a practical method for clinical manometry that reliably records LES relaxation characteristics and is amenable to both a standardized manometry protocol and a semiautomated analysis routine. Relaxation LES pressure has a high diagnostic value for achalasia.

Lower esophageal sphincter relaxation characteristics using a sleeve sensor in clinical manometry.

We undertook this study to determine the characteristics of swallow-induced lower esophageal sphincter (LES) relaxation in the setting of clinical manometry using a standardized methodology. We reviewed 170 manometric recordings performed using a perfused manometric assembly with a sleeve sensor and a computer polygraph. Patients were categorized as patient controls, gastroesophageal reflux disease (GERD), diffuse esophageal spasm (DES), or achalasia. Tracing were semiautomatically analyzed for basal LES pressure, LES pressure during deglutitive relaxation (relaxation LES pressure), duration of LES relaxation, timing of LES relaxation, and the success rate of primary peristalsis. Forty-six patient controls, 93 with GERD, five with DES, and 26 with achalasia were identified. GERD and achalasia patients had lower or higher basal LES pressures than patient controls, respectively. Compared with patient controls, achalasia patients had higher relaxation LES pressures, lower percent LES relaxation, and shorter durations of LES relaxation. The best single measure for distinguishing achalasia was the relaxation LES pressure; using the 95th percentile value of patient controls (12 mm Hg) as the upper limit of normal, its sensitivity and positive predictive value for the diagnosis of achalasia were 92% and 88%, respectively. Coupled with the finding of aperistalsis, a relaxation LES pressure > or = 10 mm Hg achieved 100% sensitivity and positive predictive value among these patients. Sleeve sensor recording is a practical method for clinical manometry that reliably records LES relaxation characteristics and is amenable to both a standardized manometry protocol and a semiautomated analysis routine. Relaxation LES pressure has a high diagnostic value for achalasia.

Aging, esophageal motility, and gastroesophageal reflux.

To compare esophageal motility and gastroesophageal reflux characteristics in young, middle-aged, and older healthy volunteers. Comparison of conventional esophageal manometry and scintigraphic study of gastroesophageal reflux in volunteers aged 20 to 30 years, 50 to 60 years, and 70 to 80 years. Gastroenterology and nuclear medicine laboratories of a tertiary care university hospital. Forty healthy adult volunteers recruited from the community, 20 aged 20 to 30 years, 10 aged 50 to 60 years, and 10 aged from 70 to 80 years. Each volunteer underwent conventional esophageal manometry and scintigraphic study of gastroesophageal reflux. Contractile wave amplitude, duration, velocity, and lower esophageal sphincter relaxation duration, as well as the presence of abnormal peristalsis, were correlated with the proportion of volunteers with gastroesophageal reflux and the number and duration of gastroesophageal reflux episodes. Quantitative manometric parameters showed no correlation with gastroesophageal reflux patterns. Abnormal peristalsis was found more frequently in the older volunteers. The number of gastroesophageal reflux episodes per volunteer was similar in the three age groups, but the duration of gastroesophageal reflux episodes was longer in the older volunteers. Healthy older persons have impaired clearance of refluxed materials associated with a high incidence of defective esophageal peristalsis. This may explain the higher severity of reflux esophagitis in older people.

Inhibition of resting lower esophageal sphincter pressure by pharyngeal water stimulation in humans

Background/Aims: Normal inhibition of lower esophageal sphincter (LES) tone occurs during swallowing and belching. However, it is known that it may occur independently of these functions. The aim of this study was to characterize the effect of pharyngeal water stimulation on resting LES pressure. Methods: The effect of rapid-pulse and slow continuous intrapharyngeal injection of minute increments of water on the resting tone of the upper and LES of 14 healthy young volunteers was evaluated by concurrent manometry, submental electromyography, and respirography. Results: At a threshold volume, pharyngeal water injection induced an isolated LES relaxation in all volunteers. The threshold volume inducing LES relaxation by rapid-pulse injection, 0.16 ± 0.01 mL, was significantly lower than that with slow continuous injection (0.5 ± 0.05 mL) ( P < 0.05). The duration and magnitude of LES relaxation were not volume dependent. The duration of LES relaxation induced by rapid-pulse injection was significantly longer than that of swallows. Conclusions: Minute amounts of liquid injected into the pharynx induce LES relaxation different from that of the normal swallow. Neither the duration nor the magnitude of this relaxation is volume dependent. Whereas the contribution of this finding to the mechanism of transient LES relaxation remains to be ascertained, it may partially explain the variability of the basal LES pressure.

On-line computer analysis of human lower esophageal sphincter relaxation.

Lower esophageal sphincter (LES) relaxation is usually interpreted by a subjective, mostly qualitative analysis. We studied sphincter relaxation in humans using a computer program for on-line analysis that provides objective measures of gastric pressure, resting LES pressure, percent of relaxation, residual pressure during relaxation, duration of relaxation, and area of relaxation. The program was validated by comparing computer-analyzed values to mean values obtained from manual readings by five individuals. Excellent correlation was obtained for all standard parameters. The parameters of LES relaxation for both wet and dry swallows were similar using either a carefully placed single recording orifice or a Dent sleeve. The one exception was the duration of LES relaxation, which was significantly shorter with the sleeve. All relaxation parameters and peristaltic velocity were then studied in 10 volunteers during 5 dry and 5 wet swallows under base-line conditions and after both atropine (10 micrograms/kg iv) and bethanechol (40 micrograms/kg sc). These studies showed that LES relaxation is affected by type of swallow (dry vs. wet). Percent of relaxation may not be the best measure of relaxation because it is too dependent on resting pressure. Residual pressure is not dependent on base-line pressure and may better define relaxation. Duration of the relaxation is dependent on the velocity of the peristaltic wave.

Motor responses of the esophagus and lower esophageal sphincter (LES) to vestibular stimulation in man.

Pressure recordings in the esophageal body, LES and stomach were performed in 10 healthy subjects before and after caloric stimulation of the labyrinth. While esophageal and stomach responses varied or were absent, all subjects showed variations at the LES level. Duration of LES relaxation was increased and both time and amplitude of LES augmentation were significantly reduced. The physiological mechanism of labyrinthine-digestive connections and the possibility of clinical applications are discussed.

Computer determination of lower esophageal sphincter relaxation (LESR) parameters studied during wet and dry swallows, orifice vs dent sleeve, and cholinergic stimulation and inhibition

COMPUTER DETERMINATION OF LOWER ESOPHAGEAL SPHINCTER RELAXATION (LESR) PARAMETERS STUDIED DURING WET AND DRY SWALLOWS, ORIFICE VS DENT SLEEVE, AND CHOLINERGIC STIMULATION AND INHIBITION. JA Castell, CB Dalton, DO Castell. Bownan Gray School of Medlcme, Winston-Salem, NC. LESR interpretation is a subjective, mostly qualitative analysis. We studied LESR in humans using on-line computer analysis to provide objective measures of gastric pressure, resting lower esophageal sphincter pressure (LESP), %LESR, residual pressure (RP) during LESR, duration (LESR/D) and area (LESR/A) of LESR. The program was validated by comparing computer analysis to manual readings by 5 individuals. Excellent correlation was obtained for all parameters (LESP: r=95 , % LESR: x-=.87, LES.R/D r=.96). LESR parameters and peristaltic velocity (VEL) were studied in 10 volunteers. Using pneumohydraulic perfusion gastric baseline pressure was obtained, LES located, and LESR parameters measured during 5 dry and 5 wet swallows at baseline and after atropine (lOpgm/kg; iv) and bethanechol (40pgm/kg;subQ). Results be10 LESP %LESR LESR/D RP LESR/A VEL __-___ Wet Swallow 14.9 93.9 10.8 1-r 30052-x Dry Swallow 13.9* 89.2* 9.3* 1.8* 2252* 3.8* Atropine a.7* 91.3 9.4 0.8 1623 3.8* Bethanechol 25.7* 96.8* 13.8 0.7 5475 2.2* * = ~~0.05 compared to baseline wet swallow There as excellent correlation VEL vs T.ESR/D (r=-.80) and LESP vs % LESR (r=+.92) but poor correlation LESP vs RP (r=+.29). %LESR changed significantly with resting LESP while RP as uneffected. Cholinergicstimulationand inhibition caused apparent changes in LESR, but these are explained by their effects on peristaltic VEL (hence LESR/D) and resting LESP (hence % LESR). Differences in LESR between wet and dry swallows were confirmed by repeating studies in 5 volunteers using Dent sleeve. Values for %LESR and LESR/D were lower and et and dry swallow differences more pronounced. CONCLUSIONS: l)LESR is affected by type of swallow (dry vs et). 2)% LESR may not be the best measure of LESR since it is too dependent on resting LESP. 3)RP is not dependent on baseline LESP and may better define LESR. 4)Duration of the LESR is dependent on the velocity of the peristaltic ave. 5) Cholinergic regulation of human LESR is minimal.

Apparent complete lower esophageal sphincter relaxation in achalasia

Seven of 23 patients (30%) seen in 2 yr with clinical and radiologic manifestations of achalasia underwent esophageal manometry demonstrating aperistalsis but apparent complete lower esophageal sphincter (LES) relaxation. Detailed clinical and laboratory evaluation suggests these patients may represent an early stage of achalasia. Duration of dysphagia and weight loss were significantly less (p < 0.05), whereas LES pressure was similar in the 7 patients compared with the 16 more traditional achalasia patients. Isotope retention during radionuclide esophageal solid-emptying studies showed intermediate delay in emptying between normal subjects and achalasia patients. The duration of LES relaxation in this group was significantly shorter (p < 0.01) than in normal subjects. Although complete, sphincter relaxation in these patients is functionally inadequate and may be the result of this shortened duration. The small size of standard manometry catheters may also contribute to this confusing finding. Apparent complete LES relaxation may be seen during manometry in achalasia and should not exclude its diagnosis.