Baseline Lower Esophageal Sphincter Pressure Research Articles

Endoscopic plication compared to laparoscopic fundoplication in the treatment of gastroesophageal reflux disease: a systematic review and meta-analysis.

Endoscopic plication offers an alternative to surgical fundoplication for treatment of gastroesophageal reflux disease (GERD). This systematic review and meta-analysis evaluate outcomes following endoscopic plication compared to laparoscopic fundoplication. Systematic search of MEDLINE, Embase, Scopus, and Web of Science was conducted in September 2022. Study followed PRISMA guidelines. Studies comparing endoscopic plication to laparoscopic fundoplication with n > 5 were included. Primary outcome was PPI cessation, with secondary outcomes including complications, procedure duration, length of stay, change in lower esophageal sphincter (LES) tone, and DeMeester score. We reviewed 1544 studies, with five included comparing 105 (46.1%) patients receiving endoscopic plication (ENDO) to 123 (53.9%) undergoing laparoscopic fundoplication (LAP). Average patient age was 47.6years, with those undergoing plication being younger (46.4 ENDO vs 48.5 LAP). BMI (26.6kg/m2 ENDO vs 26.2kg/m2 LAP), and proportion of females (42.9% ENDO vs 37.4% LAP) were similar. Patients undergoing laparoscopic procedures had worse baseline LES pressure (12.8mmHg ENDO vs 9.0mmHg LAP) and lower preoperative DeMeester scores (34.6 ENDO vs. 34.1 LAP). The primary outcome demonstrated that 89.2% of patients undergoing laparoscopic fundoplication discontinued PPI compared to 69.4% for those receiving plication. Meta-analysis revealed that plication had significantly reduced odds of PPI discontinuation (OR 0.27, studies = 3, 95% CI 0.12 to 0.64, P = 0.003, I2 = 0%). Secondary outcomes demonstrated that odds of complications (OR 1.46, studies = 4, 95% CI 0.34 to 6.32, P = 0.62, I2 = 0%), length of stay (MD - 1.37, studies = 3, 95% CI - 3.48 to 0.73, P = 0.20, I2 = 94%), and procedure durations were similar (MD 0.78, studies = 3, 95% CI - 39.70 to 41.26, P = 0.97, I2 = 98%). This is the first meta-analysis comparing endoscopic plication to laparoscopic fundoplication. Results demonstrate greater likelihood of PPI discontinuation with laparoscopic fundoplication with similar post-procedural risk.

Relationship between dysphagia, lower esophageal sphincter relaxation, and esophagogastric junction distensibility.

It is debated whether high-resolution manometric (HRM) integrated relaxation pressure (IRP) or functional lumen imaging probe (FLIP) distensibility index (DI) is the superior measure of esophagogastric junction (EGJ) opening. We examined the relationship between the DI and IRP and assessed correlations with dysphagia symptoms in patients with achalasia and EGJ outflow obstruction (EGJOO). Patients with achalasia and those with barium tablet retention at the EGJ were grouped as follows: Group 1:Achalasia (IRP≥15mmHg+complete absence of normal peristalsis); Group 2: Manometric+FLIP EGJOO (IRP≥15mmHg with some intact peristalsis+DI≤2.8mm2 /mmHg); Group 3: Abnormal DI only (DI≤2.8mm2 /mmHg+IRP <15mmHg); and Group 4: Normal IRP and DI (IRP≥15mmHg+DI>2.8mm2 /mmHg). Correlation between the DI, baseline lower esophageal sphincter pressure (BLESP), IRP, and dysphagia (Eckardt score) was assessed. Multivariable analysis was used to assess variables associated with dysphagia score ≥2. A total of 79 patients were included: Group 1 (n=31), Group 2 (n=33), Group 3 (n=14), and Group 4 (n=1). DI did not correlate with BLESP or IRP in the whole sample or subgroups. DI was the only variable associated with dysphagia score ≥2 (p=0.006). DI<1.25mm2 /mmHg had sensitivity of 87% and specificity of 52% (p=0.0003) for dysphagia score ≥2. DI does not correlate with HRM EGJ measurements and is the metric with the strongest effect on dysphagia severity. The various biological elements that may cause restrictive EGJ function should be the subject of future studies.

Efficacy of pneumodilation in achalasia after failed Heller myotomy.

Heller myotomy is an effective treatment for the majority of achalasia patients. However, a small proportion of patients suffer from persistent or recurrent symptoms after surgery and they are usually subsequently treated with pneumodilation (PD). Data on the efficacy of PD as secondary treatment for achalasia are scarce. Therefore, this study aimed to investigate the efficacy of PD as treatment for achalasia patients suffering from persistent or recurrent symptoms after Heller myotomy. Patients with recurrent or persistent symptoms (Eckardt score >3) after Heller myotomy were selected. Patients were treated with PD, using a graded distension protocol with balloon sizes ranging from 30 to 40 mm. After each dilation symptoms were assessed to evaluate whether a subsequent dilation with a larger balloon size was required. Patients with recurrent or persistent symptoms (Eckardt score >3) after treatment with a 40-mm balloon were identified as failures. Twenty-four patients were included in total; 15 patients with achalasia type I, seven with achalasia type II and two with achalasia type III. Median relapse time was 2.5 years after Heller myotomy (IQR: 9 years and 3 months). Three patients were not suitable for PD; one patient was morbidly obese and not fit for any form of sedation and two had a siphon-shaped esophagus leaving 21 patients to treat. Eight patients were successfully treated with a single 30-mm balloon dilation (median follow-up time: 6.5 years; IQR: 7.5 years). Four patients required dilations with 30- and 35-mm balloons (median follow-up time: 11 years; IQR: 3 years). Nine patients failed on the 35-mm balloon dilation and underwent a subsequent dilation with a 40-mm balloon, and all failed on this balloon as well. Thus, PD was successful in 12 of the 21 treatable patients, resulting in a success rate of 57% for treatable patients or 50% for all patients. Baseline Eckardt scores were also higher in those that failed (median: 8; IQR: 2) than those that were treated successfully (median: 5.5; IQR: 2) treated (p = 0.009). Furthermore, baseline barium column height at 5 min was higher in patients with failed (median: 6 cm; IQR: 6 cm) treatment than in patients with successful (median: 2.6 cm; IQR: 4.7 cm) treatment (p = 0.016). Baseline lower esophageal sphincter pressure was not different between patients who were treated successfully (median: 11 mmHg; IQR: 5 mmHg) and those that failed on PD (median: 17.5 mmHg; IQR: 10.8 mmHg) treatment (p > 0.05). Baseline symptom pattern was also not a predictor of successful treatment. No adverse events were recorded during or after PD. Pneumodilation for recurrent symptoms after previous Heller myotomy is safe and has a modest success rate of 57%, using 30- and 35-mm balloons. Patients with recurrent symptoms after PD with 35-mm balloon are likely to also fail after subsequent dilation with a 40-mm balloon.

Opioid-induced Lower Esophageal Sphincter Dysfunction.

The adverse gastrointestinal effects of opioids have been extensively described in medical literature.1 Their effect takes place mainly on the enteric nervous system, through receptors in the myenteric and submucosal plexuses. There are 3 recognized main opium receptors (μ, δ, and κ) that are expressed in the central and enteric nervous systems, which mediate the gastrointestinal effects.2 The mainly studied adverse gastrointestinal effect of opioids is constipation, due to the greater understanding of opium receptor physiology in the colon.3 However their effect on esophageal motility has seldom been studied. Our study’s objective was to assess esophageal motility, using high-resolution manometry (HRM), in patients undergoing long-term opioid therapy, referred for dysphagia study to the Digestive Functional Disorders Unit. A descriptive, prospective study of consecutive patients was conducted from January 2014 to May 2015. The clinical and manometric data of 5 patients with dysphagia undergoing opioid therapy were collected consecutively. In all cases, opioid therapy preceded the onset of dysphagia. There were no previous medical conditions that explained the dysphagia, and all patients underwent upper endoscopy and biopsies, with normal results. The HRM studies were performed with the patient supine after an 8-hour fast, using equipment with perfused catheters, based on our unit’s protocol.4 Manometric diagnosis was based on the international Chicago classification criteria.5 The HRM showed lower esophageal sphincter (LES) hypertonia with pathological relaxation in all cases. Based on the Chicago criteria, all 5 patients had esophageal motility disorders encompassed within the group called “motility disorders with esophagogastric junction (EGJ) outflow obstruction: Achalasia I, II, III, and functional EGJ obstruction.” Two patients met the achalasia criteria and 3 for functional EGJ obstruction criteria (Table and Figure). Three of the 5 patients required pneumatic dilation due to the severity of dysphagia, with little improvement of symptoms. Opioid medication was not able to be withdrawn in any of the cases. Figure. High-resolution manometric findings in a patient with opioid-induced dysphagia. Type III achalasia is seen. Table. High-resolution Manometric Findings in Patients With Opioid-induced Dysphagia The effect of opioids on esophageal motility has seldom been studied. Various studies with healthy volunteers have shown increased baseline LES pressure with incomplete relaxation when administering opioids.6,7 Kraichely et al8 confirmed these findings in clinical practice in a retrospective study of 15 patients with dysphagia and opioid consumption when manometry was performed. Our study evaluated the esophageal motility of patients with dysphagia and opioid consumption using HRM. The mechanism responsible for the effects of opioids on esophageal motility remains unclear; however, the nitric oxide pathway has been suggested to play an important role.8 Literature has shown that long-term opioid consumption can induce Oddi’s sphincter dysfunction, causing its muscles to spasm, which could have interaction pathways similar to those in the esophagus.9 Although clinical improvement with drugs and dilation is > 50% in published studies on the therapeutic management of esophageal motility disorders,10 these treatments in patients having opioid-induced dysphagia resulted in little response. This fact and the onset of symptoms after starting opioid treatment support the relationship between these drugs and the onset of motility disorders. In conclusion, long-term opioid use can induce esophageal motility disorders similar to achalasia or functional EGJ obstruction. These drugs should be considered in the differential diagnosis of processes that alter esophageal motility, mainly motor disorders which progress with pathological LES relaxation and sphincter hypertonia.

The light at the end of the tunnel: a single-operator learning curve analysis for per oral endoscopic myotomy

Per oral endoscopic myotomy (POEM) represents a natural orifice transluminal endoscopic surgery approach to Heller myotomy. Our center was the first to offer POEM outside of Japan, allowing us to accumulate what is likely the highest single-operator POEM volume in the United States. To define the POEM learning curve of a gastroenterologist by using a larger data set and more detailed statistical analysis than used in 2 other reports of POEM performed by surgeons. Prospective cohort study. Tertiary-care academic medical center. We analyzed the first 93 consecutive POEMs on patients with achalasia aged >18 years without contraindications to POEM performed by a single operator from October 2009 to November 2013. (1) Efficiency estimation via cumulative sum (CUSUM) analysis, (2) mastery estimation via penalized basis-spline regression and CUSUM analysis, (3) correlation of operator experience with clinical outcomes (Eckardt score improvement, lower esophageal sphincter pressure reduction) and technical errors (accidental mucosotomy rate), and (4) unadjusted and adjusted regression analysis to assess how patient characteristics affected procedure time by using a generalized linear model. Clinical outcomes, procedure time, technical errors. Efficiency was attained after 40 POEMs and mastery after 60 POEMs. When we used the adjusted regression analysis, only case number (operator experience) significantly affected procedure time (P < .0001). Improvements in clinical outcomes were excellent but not significantly affected by operator experience, as was the case with accidental mucosotomies. Procedure time was not significantly affected by age, sex, achalasia stage, baseline lower esophageal sphincter pressure, baseline Eckardt score, prior treatment of achalasia, prior botulinum toxin injection, incidence of accidental mucosotomies, length of myotomy, or type of knife used (all P > .05). Our analysis may underestimate the number of POEMs required to achieve mastery for operators with limited or no endoscopic submucosal dissection experience. These results offer thresholds for efficiency and mastery of a single gastroenterologist operator that may guide the efforts of novice POEM operators.

High-resolution manometric evaluation of the effects of cisapride and metoclopramide hydrochloride administered orally on lower esophageal sphincter pressure in awake dogs

To evaluate the effects of cisapride and metoclopramide hydrochloride administered orally on the lower esophageal sphincter (LES) resting pressure in awake healthy dogs. 6 adult Beagles. Each dog was evaluated after administration of a single dose of cisapride (0.5 mg/kg), metoclopramide (0.5 mg/kg), or placebo (empty gelatin-free capsule) in 3 experiments performed at 3-week intervals. To measure LES pressure, a high-resolution manometry catheter equipped with 40 pressure sensors spaced 10 mm apart was used. For each experiment, LES pressure was recorded during a 20-minute period with a virtual electronic sleeve emulation before treatment (baseline) and at 1, 4, and 7 hours after drug or placebo administration. A linear mixed-effects model was used to test whether the 3 treatments affected LES pressure differently. In the cisapride, metoclopramide, and placebo experiments, median baseline LES pressures were 29.1, 30.5, and 29.0 mm Hg, respectively. For the cisapride, metoclopramide, and placebo treatments, median LES pressures at 1 hour after administration were 44.4, 37.8, and 36.6 mm Hg, respectively; median LES pressures at 4 hours after administration were 50.7, 30.6, and 31.1 mm Hg, respectively; and median LES pressures at 7 hours after administration were 44.3, 28.5, and 33.3 mm Hg, respectively. The LES pressures differed significantly only between the placebo and cisapride treatments. Results suggested that orally administered cisapride may be of benefit in canine patients for which an increase in LES pressure is desirable, whereas orally administered metoclopramide did not affect LES resting pressures in dogs.

Effects of Dexmedetomidine and Propofol on Lower Esophageal Sphincter and Gastroesophageal Pressure Gradient in Healthy Volunteers

Many anesthetics reduce lower esophageal sphincter pressure (LESP). Reduced pressure and consequent reduction in the gastroesophageal pressure gradient (GEPG) thus promotes gastroesophageal reflux and may contribute to aspiration pneumonia and associated morbidity. Therefore, the authors compared LESP and GEPG during dexmedetomidine and propofol sedation. Using a randomized, double-blind, crossover design, 11 healthy volunteers were sedated on 2 separate days. Baseline LESP and GEPG were recorded each day. Subsequently, on each day volunteers received three 40-min-long sedative infusions of increasing doses of 0.6, 1.2, and 2.4 ng/ml dexmedetomidine or 1, 2, and 4 microg/ml propofol. LESP and GEPG were recorded during inhalation and expiration at 20 and 40 min after starting each infusion phase, and these measurements were averaged. Results are presented as mean (95% confidence interval). Two subjects did not return for the dexmedetomidine study day, and the dexmedetomidine results were unusable in another; propofol results in these volunteers were nonetheless retained for analysis. There were no significant differences in LESP and GEPG as a function of drug. However, there was a small but significant 7.4 (-1.6 to -13.2) mmHg (approximately 25%) dose-dependent decrease in LESP over the range of targeted low to high blood levels of each drug. Both dexmedetomidine and propofol have similar effects on LESP and GEPG. Although both of the drugs cause some decrease in LESP at high concentrations, it is unlikely that this effect would promote gastroesophageal reflux during sedation.

Endoscopic injection of skeletal muscle–derived cells augments gut smooth muscle sphincter function: implications for a novel therapeutic approach

Sphincter function is a common problem in gastroenterology and leads to disorders such as GERD and fecal incontinence. We hypothesized that transplantation of skeletal muscle-derived cells (MDCs) into GI sphincters may improve their function, leading to a more physiological approach to treating these disorders. We performed experiments to test the potential of MDCs to survive and differentiate within the GI smooth muscle in order to gain further knowledge on the biology of skeletal muscle transplantation in GI smooth muscle sphincters as well as to test the safety and feasibility of endoscopic injection of MDCs in a large animal model. Animal laboratory. Adult male Sprague-Dawley rats and adult male beagle dogs were used. Rat-derived and dog-derived MDCs were prepared in vitro and labeled with DiI. DiI-labeled, rat-derived MDCs (200,000/4 muL phosphate buffered saline solution) were injected bilaterally in the pyloric wall of rats, and survival, differentiation, and in vitro contractility were assessed 1 month after transplantation. Dog-derived MDCs (4.0 x 10(6) cells) were also injected into the lower esophageal sphincter of 3 beagle dogs by using a standard variceal sclerotherapy needle after baseline esophageal manometry and pH monitoring. The dogs were treated with daily cyclosporine, and 2 weeks later esophageal manometry was repeated and the esophagus was examined histologically. Differentiation of grafted cells was assessed by immunofluorescence, using specific antibodies to markers of the smooth muscle phenotype (smooth muscle actin) and of the skeletal muscle phenotype (skeletal muscle myosin). In rats, grafted MDCs were visualized based on DiI fluorescence and were found to be localized within the muscle wall and in the muscularis mucosa. In vitro organ bath studies showed a significant increase in the contractile response of the pyloric sphincter to exogenous acetylcholine. In dogs, MDC injection resulted in a significant increase in baseline lower esophageal sphincter pressure. Further, in 1 dog with significant baseline acid reflux, MDC injection resulted in a reduction of acid reflux, with the fraction of time with pH <4 decreasing from 26.5% to 1.5%. Transplanted MDCs were seen adding bulk to the lower esophageal area and were well-integrated into the surrounding tissue. Immunofluorescence analysis revealed weak expression of skeletal muscle myosin in grafted MDCs and no expression of smooth muscle actin in either rats or dogs. Animal study. MDCs can survive and integrate into GI smooth muscle and augment their contractile response. Thus, they may have potential for the treatment of a variety of conditions.

Effects of Intraduodenal Nutrient Infusion on CCK Levels, LES Pressure, and Gastroesophageal Reflux (GER)

Purpose: Background: Fats are associated with increased GER and CCK (cholecystokinin) is thought to play a role. The contribution of other nutrients to GER is not well described. Aims: Evaluate the effects of intraduodenal nutrient infusion on serum CCK levels, lower esophageal sphincter (LES) pressure, and GER. Methods: 24 healthy asymptomatic Caucasian volunteers were studied. A water-perfused, 6 cm Dent sleeve catheter (Dentsleeve International Ltd) was positioned across the LES fluoroscopically; an infusion port was located in the 2nd portion of the duodenum. An impedance-pH catheter (Sandhill Scientific) was attached to the catheter with the pH probe 5 cm above the upper border of the LES. After a 1-hour accommodation period baseline CCK levels were measured. Volunteers were randomized to receive one of 3 separate 60 kcal nutrient infusions over 30 minutes (2 cc/min): fat (F; Microlipid, Novartis Medical Nutrition); carbohydrate (C; Polycose, Ross Nutrition); or protein (P; Beneprotein, Novartis Medical Nutrition). All substances were dispersed in normal saline. Blood samples were drawn 5, 10, 15, and 25 minutes after nutrient infusion. LES resting pressure was measured at baseline and 60 minutes after nutrient infusion. Reflux events were categorized as either acid or non-acid in nature using a pH cut-off of 4.0. Results: No statistically significant difference was found among the 3 groups with regards to demographics, number of reflux events, number of acid events or percent of time with acid. A trend was noted for increased reflux and acid exposure events in the fat group. CCK levels were significantly higher in the fat group compared to the other 2 groups at 10, 15, and 25 minutes after nutrient infusion. The mean post-infusion LES pressure was significantly lower than mean baseline LES pressure in the F group (P= 0.02). Conclusion: Intraduodenal fat infusion led to a statistically significant increase in CCK levels in normal volunteers, while protein and carbohydrate did not. Reflux events were more frequent in volunteers infused with fat compared to protein or carbohydrate, although this did not reach statistical significance. LES pressure decreased significantly after fat infusion. Further studies are needed to better define the relationship between fat infusion, CCK release, LES pressure, and GER.Table

Minimally-Invasive Esophagomyotomy in 200 Consecutive Patients: Factors Influencing Postoperative Outcomes

The primary objective of this study was to review our experience with minimally-invasive esophagomyotomy as primary therapy for achalasia, and to identify those clinical variables most predictive of myotomy failure. We reviewed our experience with all patients who underwent minimally-invasive Heller myotomy from 1992 to 2005. Outcome variables analyzed included perioperative morbidity and mortality, symptomatic improvement, and requirement for postoperative interventions. Multivariate analysis was performed to identify clinical variables predictive of myotomy failure. A total of 200 consecutive patients (104 men and 96 women) underwent minimally-invasive laparoscopic (n = 194) or thoracoscopic (n = 6) Heller myotomy with partial fundoplication. Mean follow-up was 31.6 months. Median hospital stay was 2 days, with no operative mortality. There were 119 patients (59.5%) who had undergone prior endoscopic treatment (endoscopic dilation or botulinum toxin injection). An increased failure rate was noted in patients with prior endoscopic therapies (16.8% versus 3.7% with no prior treatment, p = 0.003). Multivariate analysis also revealed that longer duration of symptoms, sigmoidal esophageal changes, and low preoperative lower esophageal sphincter pressures impact adversely on the success of myotomy. There was an increase in treatment failures among patients undergoing preoperative endoscopic treatment. Other factors associated with failure during long-term follow-up include longer duration of symptoms, sigmoidal esophagus, and low baseline lower esophageal sphincter pressure. Although endoscopic modalities remain an important component of the armamentarium in the treatment of patients with achalasia, consideration should be given to minimally-invasive Heller myotomy as primary therapy for this condition.

Clinical outcome of rumination syndrome in adults without psychiatric illness: A prospective study

This prospective study was conducted to characterize the clinical features of adult rumination syndrome, in the absence of psychiatric illness, by applying newly modified clinical criteria, and to elucidate factors influencing outcomes after treatment. Twenty-one adult patients diagnosed with rumination syndrome at a tertiary referral center over a 2-year period were enrolled in the study. All patients received supportive psychotherapy and medical treatment. Changes in symptom parameters were analyzed using a pretreatment and a post-treatment questionnaire. Patients were classified into three groups according to symptomatic outcome: improved group, sustained group and aggravated group. The duration of treatment was longer in the improved group than in the sustained or aggravated groups (P = 0.018). Esophageal manometry testing demonstrated non-transmitted contractions of the esophageal body in 10 patients (47.6%) and low amplitude contractions in eight patients (38.1%). Mean lower esophageal sphincter (LES) pressure was 9.8 +/- 2.6 mmHg. Baseline LES pressure in the improved group was higher than in the other groups (P = 0.001). Ambulatory 24-h esophageal pH monitoring showed pathological acid reflux in six patients (28.6%). All pathological acid reflux occurred in post-rumination periods. Scintigraphic testing of gastric emptying revealed that the mean retention rate at 120 min was 34.2 +/- 2.5% of initial contents, and delayed emptying was noted in three patients (14.3%). Rumination syndrome is often accompanied by heterogeneous conditions such as postprandial gastroesophageal reflux, various abnormalities in esophageal manometric tests and delayed gastric emptying. Medical treatment and supportive psychotherapy can be effective in otherwise normal adult patients, especially in patients who comply with long durations of treatment and who demonstrate higher baseline LES pressures.

Effect of endoluminal gastroplication in patients with classic reflux symptoms and minimally abnormal esophageal pH studies

Purpose: Traditionally patients with classic reflux symptoms but minimally abnormal esophageal pH studies have not been considered ideal surgical candidates. Endolummal gastroplication (ELGP) has been shown to improve clinical outcome in patients with gastroesophageal disease (GERD) but it remains unclear if equally impressive improvements occur in this patient population. The aim of this study is to evaluate symptomatic outcome after ELGP in patients with reflux symptoms and minimally abnormal pH studies. Methods: Patients with GERD and minimally abnormal DeMeester scores defined as less than or equal to 30 were included. Between July 2001-July 2002, 23 patients who underwent ELGP for GERD met this criterion. All ELGPs were performed with 2 or 3 plications placed 1 to 2 cm below the gastroesophageal junction. Follow-up data included weight, BMI, heartburn frequency score (HFS), heartburn severity (HSV), heartburn symptom score (HSS), regurgitation frequency (RFS), and medication use; in 3 patients manometries, pH studies, and upper endoscopy findings were obtained at variable intervals after ELGP. Results: For the 23 patients, average age was 51 with 11 men, 12 women and average BMI 28. Nine of 23 patients had a history of previous surgical fundoplication. Only 1 patient was not on medication'before or after the ELGP. On average at baseline patients reported only a 36% improvement in symptoms on medications. Average baseline lower esophageal sphincter pressure (LESP) was low at 17.4 +/-8.6mmHg with DeMeester scores of 18.5+/-9.0. Mean follow up was 4.3 months. For all symptom scores, improvement occurred POst-ELGP (all p<0.02): HFS (0-3) from 2.4 to 1.2, HSS (0-96) from 48 to 19, HSV (0-32) from 18 to 10, and RFS (0-3) from 1.9 to 0.6. After ELGP, 68% of patients were off medications, 9% had decreased usage of medications, and 23% had no change in medications. Extraesophageal symptoms also improved: 100% of nocturnal symptoms (5 of 5), 75% of atypical chest pain (3 of 4) and cough (3 of 4), and 50% of hoarseness (2 of 4) resolved. The trend after ELGP for manometry, pH study, and upper endoscopy data was improvement: LESP from 18 to 21.75 mmHg, % time pH<4 from 3.4 to 2.2, and DeMeester scores from 14.6 to 7.9. None of the 3 patients with post-ELGP endoscopies had Barrett's but esophagitis in one patient had healed after ELGP. Conclusions: ELGP significantly improves clinical outcome in patients with GERD and persistent symptoms on medical therapy even with minimally abnormal pH studies.

Intrasphincteric botulinum toxin injection in the treatment of chagasic achalasia*

According to the WHO, 16-18 million people in Central and South America are infected by Trypanosoma cruzi. Chagasic achalasia affects between 7.1% and 10.6% of the population. The aim of this study was to evaluate the effects of Botox injections in the clinical response and esophageal function of patients with dysphagia due to chagasic achalasia. In total, 24 symptomatic patients with chagasic achalasia were randomly chosen to receive Botulinum Toxin (BT) or saline injected by endoscopy in the lower esophageal sphincter (LES). Patients were monitored with a clinical score of dysphagia and an objective assessment (esophagograms, scintillography, manometry, and nutritional assessment) for a period of 6 months. Clinical improvement of dysphagia was statistically significant (P < 0.001) in patients receiving BT when compared with the placebo. There was no significant difference in the placebo group regarding clinical score, LES basal pressure and esophageal emptying time. Esophageal emptying time in the toxin group was significantly lower than in the placebo (P=0.04) after 90 days. There were non-significant increases in esophageal emptying of 25.36% and 17.39%, respectively, at 90 and 180 days, in the BT group (P=0.266). Gender, age, and baseline LES pressure did not influence the response to BT. Our data strongly suggests that intrasphincteric injection of BT in LES is clinically effective in the treatment of chagasic achalasia.

Lower esophageal sphincter pressure during prolonged cardiac arrest and resuscitation: Ann Emerg Med 1995; 26/2: 216–219

Abstract Study objective: Unprotected airway ventilation models have been based on a lower esophageal sphincter (LES) pressure found in human beings under general anesthesia. Whether this assumption is applicable during cardiac arrest in human beings is unknown. We attempted to determine the effects of prolonged ventricular fibrillation (VF) on the tension of the LES in a swine model of cardiac arrest. Design: Prospective experimental trial using 18 female mixed- breed domestic swine (mean weight, 21.9±2.0 kg). Results: Animals were anesthetized, intubated, and fitted with instruments for the monitoring of LES pressure. LES tone was measured with a LECTRON 302 esophageal monitor (American Antec, Incorporated). VF was induced with a 3-second, 100 mA transthoracic shock and left untreated for 8 minutes; then resuscitation was attempted. LES tension was measured during the first 7 minutes of the arrest. If return of spontaneous circulation (ROSC) occurred, LES pressure was measured for 7 more minutes. The mean baseline LES pressure was 20.6±2.8 cm H 2 O. During minutes 1 through 7 of the arrest the LES tone (mean±SD) decreased from 18.0±3.0 to 3.3±4.2. ROSC occurred in 10 of the 18 trials. In the 7 minutes after ROSC, LES pressure increased from 4.7±3.8 to 9.8±3.0. Conclusion : This study demonstrated a rapid and severe decrease in LES tone during prolonged cardiac arrest. When ROSC occurred, LES tension increased quickly but did not return to baseline. [Bowman FP, Menegazzi JJ, Check BD, Duckett TM: Lower esophageal sphincter pressure during prolonged cardiac arrest and resuscitation. Ann Emerg Med August 1995;26:216-219.]

Lower Esophageal Sphincter Pressure During Prolonged Cardiac Arrest and Resuscitation

Study objective: Unprotected airway ventilation models have been based on a lower esophageal sphincter (LES) pressure found in human beings under general anesthesia. Whether this assumption is applicable during cardiac arrest in human beings is unknown. We attempted to determine the effects of prolonged ventricular fibrillation (VF) on the tension of the LES in a swine model of cardiac arrest. Design: Prospective experimental trial using 18 female mixed- breed domestic swine (mean weight, 21.9±2.0 kg). Results: Animals were anesthetized, intubated, and fitted with instruments for the monitoring of LES pressure. LES tone was measured with a LECTRON 302 esophageal monitor (American Antec, Incorporated). VF was induced with a 3-second, 100 mA transthoracic shock and left untreated for 8 minutes; then resuscitation was attempted. LES tension was measured during the first 7 minutes of the arrest. If return of spontaneous circulation (ROSC) occurred, LES pressure was measured for 7 more minutes. The mean baseline LES pressure was 20.6±2.8 cm H 2O. During minutes 1 through 7 of the arrest the LES tone (mean±SD) decreased from 18.0±3.0 to 3.3±4.2. ROSC occurred in 10 of the 18 trials. In the 7 minutes after ROSC, LES pressure increased from 4.7±3.8 to 9.8±3.0. Conclusion : This study demonstrated a rapid and severe decrease in LES tone during prolonged cardiac arrest. When ROSC occurred, LES tension increased quickly but did not return to baseline. [Bowman FP, Menegazzi JJ, Check BD, Duckett TM: Lower esophageal sphincter pressure during prolonged cardiac arrest and resuscitation. Ann Emerg Med August 1995;26:216-219.]

Effects of intrasphincteric botulinum toxin on the lower esophageal sphincter in piglets

Background: The toxin of Clostridium botulinum (BoTx) inhibits the release of acetylcholine from nerve terminals and causes paralysis of skeletal muscle. The present study examined the hypothesis that BoTx may have a similar effect on gastrointestinal smooth muscle. Methods: Baseline lower esophageal sphincter (LES) pressures were obtained in five piglets, and normal saline was injected endoscopically into the LES. One week later, LES pressure was measured again, followed by injection of BoTx into the LES. After another week, LES pressure was measured again. Results: Compared with a baseline LES pressure of 8.2 ± 1.5 mm Hg, LES pressure decreased to 3.2 ± 1.0 mm Hg after BoTx injection, a reduction of about 60% (P < 0.01). By contrast, LES pressure did not change significantly after normal saline injection. The animals showed no evidence of toxicity. Data from other experiments showed that after injection with toxin, the LES responds normally to bethanechol and pentagastrin but displays a paradoxical response to edrophonium and cholecystokinin. Conclusions: BoTx is a potent inhibitor of resting LES tone. Its relatively specific anticholinergic effect may help clarify the role of cholinergic and noncholinergic pathways in the regulation of gastrointestinal sphincters.

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.

Reduced lower esophageal sphincter (LES) pressure after acute and chronic brain injury

Symptomatic gastroesophageal reflux (GER) is commonly observed in patients with brain damage. This study evaluates the effect of acute and chronic brain injury on lower esophageal sphincter (LES) pressure in an attempt to determine a possible mechanism for GER in these cases. Adolescent (8 Ib) cats were anesthetized with pentobarbital (30 mg/kg). Baseline LES pressure was determined by conventional manometrics. Bilateral fronto-parietal cranial burr holes were made and an epidural intracranial pressure (ICP) monitor inserted in one side and a silastic balloon catheter in the other. ICP was increased by balloon inflation. LES pressure was measured acutely (at varying ICP's) and at 2 and 6 wk after the procedure. Mean pre-operative LES was 19.8±6.63 torr. At ICP of 20 torr, LES pressure was significantly reduced to 6.84 ( p p