Preoperative Lower Esophageal Sphincter Research Articles

EFFICACY OF LAPROSCOPIC HELLER'S MYOTOMY IN THE TREATMENT OF ACHALASIA

In a retrospective study conducted from September 6, 2021, to September 6, 2022, at the Thoracic Surgery Department of Bakhtawar Amin Trust Hospital in Multan, the objective was to evaluate the impact of laparoscopic Heller's Myotomy on patients with achalasia. Additionally, the study sought to identify pre-operative factors that influence treatment outcomes. The methodology involved recording pre-operative patient data, including dysphagia scores, and conducting pre-operative manometry to diagnose achalasia. The diagnostic criteria included a non-relaxing lower esophageal sphincter (LES) and abnormal esophageal contractions. Post-operative changes in dysphagia scores (delta) were calculated, and a dysphagia score falling below a specified cutoff was considered an unsuccessful treatment outcome. The study's results revealed that the patients had an average age of 48.5 years, with a standard deviation of 1.6. After Heller myotomy, the average decrease in dysphagia scores was 7.2, with a standard deviation of 2.5. A change in score of ≥5 was indicative of successful treatment, leading to dysphagia relief in 69 out of 80 patients (86%). The sole pre-operative variable that significantly predicted successful dysphagia relief was the pre-operative LES pressure. The responder group displayed higher LES pressure than the non-responder group, with 41.5 mm Hg ± 12.1 and 22.9 mm Hg ± 7.1, respectively (P = 0.001). No significant correlation was observed between post-operative LES pressure and changes in dysphagia scores. In conclusion, Heller's myotomy demonstrated excellent efficacy in providing dysphagia relief for achalasia patients. Notably, a high pre-operative LES pressure was identified as a significant predictor of an excellent treatment outcome.

GERD after Peroral Endoscopic Myotomy: Assessment of Incidence and Predisposing Factors.

Peroral endoscopic myotomy (POEM) is an effective intervention for achalasia, but GERD is a major postoperative adverse event. This study aimed to characterize post-POEM GERD and identify preoperative or technical factors impacting development or severity of GERD. This is a retrospective review of patients who underwent POEM at our institution. Favorable outcome was defined as postoperative Eckardt score of 3 or less. Subjective GERD was defined as symptoms consistent with reflux. Objective GERD was based on a DeMeester score greater than 14.7 or Los Angeles grade C or D esophagitis. Severe GERD was defined as a DeMeester score greater than 50.0 or Los Angeles grade D esophagitis Preoperative clinical and objective data and technical surgical elements were compared between those with and without GERD. Multivariate logistic analysis was performed to identify factors associated with each GERD definition. A total of 183 patients underwent POEM. At a mean ± SD follow-up of 21.7 ± 20.7 months, 93.4% achieved favorable outcome. Subjective, objective, and severe objective GERD were found in 38.8%, 50.5%, and 19.2% of patients, respectively. Of those with objective GERD, 24.0% had no reflux symptoms. Women were more likely to report GERD symptoms (p = 0.007), but objective GERD rates were similar between sexes (p = 0.606). The independent predictors for objective GERD were normal preoperative diameter of esophagus (odds ratio [OR] 3.4; p = 0.008) and lower esophageal sphincter (LES) pressure less than 45 mmHg (OR 1.86; p = 0.027). The independent predictors for severe objective GERD were LES pressure less than 45 mmHg (OR 6.57; p = 0.007) and obesity (OR 5.03; p = 0.005). The length of esophageal or gastric myotomy or indication of procedure had no impact on the incidence or severity of GERD. The rate of pathologic GERD after POEM is higher than symptomatic GERD. A nonhypertensive preoperative LES is a predictor for post-POEM GERD. No modifiable factors impact GERD after POEM.

Hypotonic Low Esophageal Sphincter Is Not Predictive of Gastroesophageal Reflux Disease After Sleeve Gastrectomy.

Sleeve gastrectomy is the most commonly performed bariatric surgery these days but is associated with de novo reflux. We aimed to study the influence of hypotonic lower esophageal sphincter (LES) on postoperative gastroesophageal reflux disease (GERD). Patients with pre- and postoperative esophageal high-resolution manometry (HRM) and 24-h pH monitoring (pHM) were included retrospectively in our study. Preoperative hypotonic LES was defined by a mean residual pressure of the lower esophageal sphincter < 4mmHg. Postoperative GERD was defined by a DeMeester's score > 14.72. We also evaluated postoperative manometric changes at the esophageal-gastric junction. Sixty-nine patients (54 females and 15 males) had pre- and postoperative HRM and pHM. The mean age was 45.9 ± 9.8years. The mean body mass index (BMI) was 47.5 ± 7.5kg/m2. Hypotonic LES concerned 21 patients (30.4%) before sleeve gastrectomy. The mean time between the two esophageal monitorings was 32.1 ± 24.1months. The sensitivity, specificity, positive predictive value, and negative predictive value of hypotonic LES to predict GERD were 31, 70, 52, and 48% respectively. The LES minimal residual pressure was not statistically decreased after sleeve gastrectomy (p= 0.24). Only the wave speed, esophageal length, and LES length were significantly reduced after SG (p = 0.029, 3.8 × 10-7 and 0.00032). Hypotonic LES has a poor predictive value on postoperative GERD. The LES's length is significantly reduced after SG and this could be a factor explaining de novo reflux.

Manometric Changes to the Lower Esophageal Sphincter After Magnetic Sphincter Augmentation in Patients With Chronic Gastroesophageal Reflux Disease.

To evaluate the manometric changes, function, and impact of magnetic sphincter augmentation (MSA) on the lower esophageal sphincter (LES). Implantation of a MSA around the gastroesophageal junction has been shown to be a safe and effective therapy for gastroesophageal reflux disease, but its effect on the LES has not been elucidated. Retrospective case control study (n = 121) evaluating manometric changes after MSA. Inclusion criteria consisted of a confirmed diagnosis of gastroesophageal reflux disease by an abnormal esophageal pH study (body mass index <35 kg/m, hiatal hernia <3 cm, and absence of endoscopic Barrett disease). Manometric changes, pH testing, and proton pump inhibitor use were assessed preoperatively and 6 and 12 months after MSA. MSA was associated with an overall increase in the median LES resting pressure (18 pre-MSA vs 23 mm Hg post-MSA; P = 0.0003), residual pressure (4 vs 9 mm Hg; P < 0.0001), and distal esophageal contraction amplitude (80 vs 90 mm Hg; P = 0.02). The percent peristalsis remained unaltered (94% vs 87%; P = 0.71).Overall, patients with a manometrically defective LES were restored 67% of the time to a normal sphincter with MSA. Those with a structurally defective or severely defective LES improved to a normal LES in 77% and 56% of patients, respectively. Only 18% of patients with a normal preoperative manometric LES deteriorated to a lower category. MSA results in significant manometric improvement of the LES without apparent deleterious effects on the esophageal body. A manometrically defective LES can be restored to normal sphincter, whereas a normal LES remains stable.

Is preoperative manometry necessary for evaluating reflux symptoms in sleeve gastrectomy patients?

BackgroundThe effect of laparoscopic sleeve gastrectomy (LSG) in gastroesophageal reflux disease (GERD) is controversial. However, it has been reported that up to 22% of patients presented with symptomatic GERD after LSG. The aim of our study was to evaluate the necessity of preoperative manometric testing in LSG patients. MethodsWe prospectively collected the data on LSG candidate patients who underwent preoperative manometric testing. The normal range for the lower esophageal sphincter (LES) pressure is 10.0–45.0 mmHg. Each patient was interviewed for the GERD score questionnaire (scaled severity and frequency of heartburn, regurgitation, epigastric pain, epigastric fullness, dysphagia and cough) at the time of the manometric study. ResultsForty-nine patients were studied. The mean preoperative LES pressure was 13.2±7.7 mmHg (range, 1.0–34.4). Eleven patients responded that they had 1 or more moderate to severe GERD symptoms >2–4 times a week, of which 9 had competent LES pressures. Thirteen (26.5%) patients had decreased LES pressures, and only 3 (23.1%) of these reported moderate to severe symptoms of GERD. In 26 LSG patients with postoperative results, the mean preoperative LES pressure was 14.8±8.0 mmHg (range, 3.5–34.4), and the mean GERD score did not show a significant difference at 9 months after LSG. Twenty-two had normal LES pressures, and 16 (72.8%) of these patients reported reflux symptoms preoperatively. Only 2 (12.5%) of these symptomatic patients reported a higher GERD score postoperatively, but the difference was not significant. Of the 4 patients who had low LES pressures, only 1 patient complained of mild GERD symptoms preoperatively. However, this patient and another without preoperative symptoms developed severe GERD symptoms postoperatively. ConclusionManometric study may be necessary in LSG patients to accurately evaluate GERD and the LES pressure.

Heller myotomy and intraluminal fundoplication: a NOTES technique

It is generally accepted that the most effective treatment of achalasia is a surgical myotomy. Nevertheless, if a myotomy alone is performed, reflux may occur in up to 30% of patients. The aim of this study was to explore a transoral incisionless stepwise approach to both esophageal Heller myotomy and fundoplication. The first step consisted of creating the esophageal myotomy. Under general anesthesia, with the pig supine, endoscopy was performed to assess the location of the esophagogastric junction (EGJ). The mucosa on the right posterolateral esophageal wall was cut with the needle-knife 15 cm above the lower esophageal sphincter (LES) and then dilated with blunt dissection to introduce the scope. A submucosal tunnel was created distally with CO(2) and blunt dissection. Once the gastroesophageal junction (GEJ) and the clasp fibers were identified, the muscular layer was cut. The scope was withdrawn into the lumen and the mucosal flap was sealed with endoscopic clips. The adequacy of the myotomy was evaluated using pre- and postoperative manometry and by comparing the EGJ distensibility before, during, and after the division of the esophageal muscular fibers using the functional lumen imaging probe, EndoFLIP®. The second step, consisted of building a transoral incisionless fundoplication 4 weeks postoperatively using the EsophyX™. Both Heller myotomy and endoscopic fundoplication were accomplished successfully with no injury to the esophageal mucosa. Postoperative manometry demonstrated a 50% loss in mean LES pressure (mean preoperative LES pressure = 22.2 mmHg; mean postoperative LES pressure = 10 mmHg, P < 0.005). The EndoFLIP® showed a preoperative minimal diameter of 6 mm with a cross-sectional area of 28 mm(2). Postoperatively, the junction was more compliant (minimal diameter = 15 mm; cross-sectional area = 177 mm(2)), with the main improvement in distensibility occurring when the clasps fibers were removed. A stepwise transoral incisionless approach to esophageal Heller myotomy and partial fundoplication is feasible and effective in the porcine model. A distensibility test such as the EndoFLIP® may provide better information on the opening and closing dynamics of the EGJ, rather than just relying on the sphincter tonic state as measured by manometry.

Preoperative Lower Esophageal Sphincter Manometry Data Neither Impact Manifestations of GERD nor Outcome After Laparoscopic Nissen Fundoplication

BackgroundExperience with laparoscopic antireflux surgery (LARS) in patients with gastroesophageal reflux disease (GERD) and manometrically intact lower esophageal sphincter (LES) is limited. The disease pattern may be different and LARS may fail to control reflux or result in higher rates of dysphagia. This is the first study investigating the impact of preoperative LES manometry data not only on manifestations of GERD and subjective outcome alone but also on objective outcomes 1 year after LARS. MethodsThree hundred fifty-one GERD patients underwent LARS and had subjective symptom and quality of life assessment, upper gastrointestinal endoscopy, barium swallow esophagogram, 24-h esophageal pH monitoring, and manometry pre- and 1 year postoperatively. Patients were divided into those with a preoperatively intact versus defective LES based on intraabdominal length and resting pressure. Baseline and 1-year postoperative follow-up data were compared. ResultsPreoperative manifestations of GERD were similar in each group. Postoperatively, all symptoms except flatulence, quality of life scores, and objective manifestations improved significantly in each group. ConclusionsThe preoperative manometric character of the LES neither impacts the manifestations of GERD nor subjective and objective outcomes after LARS. Patients with GERD and manometrically intact LES have no higher risk for postoperative dysphagia.

Four Hundred Laparoscopic Myotomies for Esophageal Achalasia

Laparoscopic myotomy is the currently preferred treatment for achalasia. Our objectives were to assess the long-term outcome of this operation and preoperative factors influencing said outcome. Demographic and clinical characteristics and data on long-term outcome were prospectively collected on patients undergoing laparoscopic myotomy for achalasia at our institution from 1992 to 2007. Treatment failure was defined as a postoperative symptom score higher than the 10th percentile of the preoperative score (>9). Logistic regression analysis was used to identify independent preoperative factors associated with successful myotomy. Four hundred seven consecutive patients (220 men, 187 women) underwent the laparoscopic Heller-Dor procedure during the study period; 89 (22%) of them had previously had endoscopic treatment(s). The mortality rate was 0; the conversion and morbidity rates were 1.5% and 1.9%, respectively. The operation failed in 10% of patients (39/407) and the 5-year actuarial probability of being asymptomatic was 87%. Most failures (25/39, 64%) occurred within 12 months of the operation and can be considered as technical failures (incomplete myotomy). Pneumatic dilation overcome the dysphagia in 75% of patients whose surgery was unsuccessful. Considering both the primary surgery and this ancillary treatment, the operation was effective in 97% of achalasia patients. The frequency of sigmoid esophagus, lower esophageal sphincter (LES) resting pressures, and chest pain scores differed statistically between patients with and without recurrences. At multivariate analysis, high preoperative LES pressures (>30 mm Hg) was an independent predictor of a good response. The presence of chest pain and of sigmoid esophagus independently predicted the failure of the procedure. Laparoscopic myotomy can durably relieve dysphagia symptoms. High preoperative LES pressures represent the strongest predictor of a positive outcome, probably reflecting a less severely damaged esophageal muscle.

Preoperative lower esophageal sphincter pressure has little influence on the outcome of laparoscopic Heller myotomy for achalasia.

It is believed that in untreated patients with achalasia, the lower esophageal sphincter (LES) is almost always hypertensive and a Heller myotomy resolves symptoms by decreasing the LES pressure. The incidence of a normal or hypotensive LES in untreated achalasia patients is unknown. The goals of this study were to determine the incidence of a normal or hypotensive LES in untreated achalasia patients and the outcome of laparoscopic Heller myotomy in achalasia patients with either normal or low LES pressure. Between January 1990 and May 2002, a diagnosis of achalasia was made in 239 patients. Among 109 patients (46%) who had not previously received any form of treatment, 53 patients underwent laparoscopic Heller myotomy and Dor fundoplication. Based on the preoperative LES pressure (normal, 14-24 mmHg) they were divided into three groups: group A--four patients (7.5%), LES pressure <14 mmHg; group B--18 patients (34%), LES pressure 14-24 mmHg; and group C-31 patients (58.5%), LES pressure >24 mmHg. Among the 109 untreated patients, the LES was hypertensive in 49 patients (45%), normal in 29 patients (27%), and hypotensive in 31 patients (28%). The clinical outcome was good among the three groups of patients who underwent laparoscopic Heller myotomy, with poor outcome in only approximately 10% in each group. These data show that in 55% of untreated. achalasia patients the LES pressure is either normal or low, and that laparoscopic Heller myotomy usually relieves symptoms regardless of preoperative LES pressure.

Barrett's esophagus can and does regress after antireflux surgery: a study of prevalence and predictive features.

To investigate the factors leading to histologic regression of metaplastic and dysplastic Barrett's esophagus (BE). The study sample consisted of 91 consecutive patients with symptomatic Barrett's esophagus. Pre- and posttreatment endoscopic biopsies from 77 Barrett's patients treated surgically and 14 treated with proton pump inhibitors (PPI) were reviewed. An expert pathologist confirmed the presence of intestinal metaplasia (IM) with or without dysplasia. Posttreatment histology was classified as having regressed if two consecutive biopsies taken more than 6 months apart plus all subsequent biopsies showed loss of IM or loss of dysplasia. Clinical factors associated with regression were studied by multivariate analysis, as was the time course of its occurrence. Histopathologic regression occurred in 28 of 77 patients (36.4%) after antireflux surgery and in 1 of 14 patients (7.1%) treated with PPIs alone (p < 0.03). After surgery, regression from low-grade dysplastic to nondysplastic BE occurred in 17 of 25 patients (68%) and from IM to no IM in 11 of 52 (21.2%). Both types of regression were significantly more common in short (< 3 cm) than long (> 3 cm) segment Barrett's esophagus; 19 of 33 (58%) and 9 of 44 (20%) patients, respectively (p = 0.0016). Eight patients progressed, five from IM alone to low-grade dysplasia and three from low- to high-grade dysplasia. All those who progressed had long segment BE. On multivariate analysis, presence of short segment Barrett's and type of treatment were significantly associated with regression; age, gender, surgical procedure, and preoperative lower esophageal sphincter and pH characteristics were not. The median time of biopsy-proved regression was 18.5 months after surgery, with 95% occurring within 5 years. This study refutes the widely held assumption that once established, Barrett's esophagus does not change. More than one-third of patients with visible segments of Barrett's esophagus undergo histologic regression after antireflux surgery. Regression is dependent on the length of the columnar-lined esophagus and time of followup after antireflux surgery.

Laparoscopic antireflux surgery: preoperative lower esophageal sphincter pressure does not affect outcome.

Concern has been raised about operating on patients with gastroesophageal reflux disease (GERD) and normal lower esophageal sphincter (LES) pressure for the fear that a fundoplication may fail to control reflux and result in a high rate of postoperative dysphagia. We hypothesized that fundoplication is effective in patients with GERD irrespective of the preoperative LES pressure, and that in patients with normal LES pressure, a total fundoplication does not result in a high incidence of dysphagia. We studied 280 unselected patients with GERD who underwent laparoscopic fundoplication. They were divided in three groups based on the preoperative LES pressure (normal, 14-24 mmHg): group A (LES pressure, 0-6 mmHg; 61 patients; 22%); group B (LES pressure, 7-13 mmHg; 178 patients; 64%); group C (LES pressure, >or=14 mmHg; 41 patients; 14%). De novo dysphagia was defined as new onset of postoperative dysphagia lasting more than 10 weeks. The average follow-up period was 17 +/- 22 months. There was no difference in resolution of symptoms among the three groups. Heartburn and regurgitation resolved or improved respectively in 96% of group A, 90% of group B, and 91% of group C patients. In addition, there was no difference in the incidence of de novo dysphagia, which occurred in 8% of group A, 7% of group B, and 2% of group C. We conclude that fundoplication controlled GERD irrespective of preoperative LES pressure, and that a normal LES pressure before surgery was not associated with a higher rate of postoperative dysphagia.

Physiologic Mechanism and Preoperative Prediction of New-Onset Dysphagia After Laparoscopic Nissen Fundoplication

The aim of this study was to determine whether preoperative physiologic factors can account for and be used to predict the development of postoperative dysphagia after laparoscopic Nissen fundoplication. One hundred sixty-three patients with gastroesophageal reflux disease underwent laparoscopic Nissen fundoplication with a median follow-up of 14 months (range 6 to 81 months). Preoperative dysphagia was present in 37% (60 of 163) and was relieved in all but five patients (92%). Female sex ( P = 0.01) and the presence of a stricture ( P = 0.02) were the only preoperative variables associated with the presence of preoperative dysphagia. Eight percent (8 of 103) of patients without preoperative dysphagia developed new-onset dysphagia, and of these 63% (5 of 8) had a normal lower esophageal sphincter (LES) (pressure >6 mm Hg; length >2 cm; abdominal length >1 cm). New-onset dysphagia was significantly more common in patients with a normal LES (22% [5 of 23] vs. 4% [3 of 80], P = 001). Patients with a normal LES had almost a sixfold increase in the risk of developing dysphagia as those with an abnormal LES (relative risk = 5.8). Only a preoperative normal LES ( P = 0.02) or mean LES pressures ( P = 0.04) were positively associated with the development of postoperative dysphagia. The severity of this dysphagia also showed a strong positive trend of increasing with mean preoperative LES pressures ( P = 0.07). Finally, preoperative LES pressure significantly correlated with postoperative LES pressure ( r = 0.48, P = 0.01) and with mean residual LES (nadir) pressure ( r = 0.33, P = 0.05) offering insight into the mechanism of this dysphagia. In conclusion, preoperative LES parameters play a role in the development of dysphagia after laparoscopic Nissen fundoplication. Patients with a normal LES or high mean LES pressures are at increased risk for developing this complication and should be informed of this before laparoscopic Nissen fundoplication. ( J Gastrointest Surg 2002;6:22–28.)

Heller's myotomy: thoracoscopic or laparoscopic?

Cardiomyotomy is now usually performed using a minimally invasive approach. A consecutive series of 18 patients with an intention to treat thoracoscopically were followed by the same number of patients treated laparoscopically. Both groups have been followed prospectively for a minimum of 2 years. The groups were well matched for age, symptom duration, preoperative lower esophageal sphincter pressure, and number having undergone balloon dilatation. There was one conversion from a thoracoscopic to a laparoscopic approach so that, for the purpose of analysis, there are 17 in the thoracoscopic group and 19 in the laparoscopic group. There was no difference in the average operating time, rate of conversion to open operation, mucosal breaches, or length of hospitalization. Nor was there any difference in dysphagia symptoms, with 14/17 having a satisfactory result after thoracoscopic myotomy and 18/19 after laparoscopic myotomy. Frequency of reflux symptoms was similar and, although mild reflux was common, only two patients required treatment with a proton pump blocker. In the treatment of achalasia, thoracoscopic and laparoscopic myotomy without fundoplication are equally effective in relieving dysphagia and have a similar safety profile.

Laparoscopic esophagomyotomy without an antireflux procedure for the treatment of achalasia.

Various gastroenteric surgical procedures have been attempted laparoscopically. Laparoscopic esophagomyotomy (LE) with or without fundoplication, performed for achalasia, has gained popularity. In our clinic, LE (Heller's myotomy) was performed on six patients with achalasia. All patients underwent barium esophagography, endoscopy, and esophageal manometry for diagnosis. Extramucosal myotomy was started 6 cm above the cardioesophageal junction on the left anterolateral aspect of the esophagus and continued 1 cm below this area. Endoscopic control of the distal esophageal mucosa and the stomach was carried out under direct laparoscopic visualization following the completion of myotomy during the operation. LE was completed without complication in five patients. In one patient (16%), mucosal perforation occurred after myotomy during endoscopic control and was repaired with endostitches. There were no postoperative complications. The average hospital stay was 3 days. Three of the six patients agreed to 24-h pH monitoring, the results of which showed no evidence of reflux. All patients were completely symptom free in the postoperative period. The average preoperative lower esophageal sphincter pressure was 44 mm Hg, whereas in the early postoperative period and 6 months later, it was 11 mm Hg. There was no dysphagia or reflux esophagitis during the follow-up period (range 12 to 24 months). LE is associated with low morbidity and a high success rate, comparable with an open procedure, and can be done without an antireflux procedure.

Manometric study of vertical banded gastroplasty for morbid obesity.

Morbidly obese patients undergoing vertical banded gastroplasty were studied preoperatively and/or postoperatively to characterize its manometric pattern. The esophageal manometry using station pull through technique involved 14 preoperative patients with a mean age of 28 +/- 7 years who were a obesity index of 220 +/- 32% and 14 postoperative patients with a mean age of 30 +/- 7 years who were a obesity index of 158 +/- 23%. Preoperative lower esophageal sphincter (LES) pressure using gastric base line as O was 16.1 +/- 8.5 cmH2O and a LES length of 3.4 +/- 0.9 cm. Postoperatively, the vertical banded gastroplasty channel had a pressure of 17.7 +/- 7.1 cmH2O and a length of 8.2 +/- 1.7 cm which was higher than gastric base line. No difference was seen between preoperative LES pressure and postoperative channel pressure, however postoperative channel length was significantly (p less than 0.01) larger than preoperative LES length. We concluded that vertical banded gastroplasty for morbid obesity created a longer high pressure zone in accordance with channel which would inhibit reflux of gastric juice.

Reduction of lower esophageal sphincter pressure with stamm gastrostomy

Although recent clinical studies suggest an association between Stamm gastrostomy and gastroesophageal reflux (GER), no significant experimental data is available. This study evaluates alterations in lower esophageal sphincter (LES) pressure after Stamm gastrostomy in cats. Eight male cats (average weight 3 to 4 kg) were induced under general anesthesia using 20/mg/kg ketamine intramuscularly (IM). Esophageal manometrics were determined for each animal using a continuous perfusion catheter and recording system. Three measurements were taken for each animal. Stamm gastrostomy was then placed in the anterior wall of the stomach two thirds of the way down from the fundus. This was tacked to the anterior abdominal wall 3.0 cm lateral to the midline at the appropriate longitudinal level. Esophageal manometry was repeated after abdominal closure. The animals were awakened and returned to their cages for ad libidum feedings. The animals were reanesthetized with ketamine and manometrics repeated at 7 and 14 days. Each animal served as its own control. Five animals underwent barium esophagram 14 days postoperatively to evaluate for GER. Preoperative mean LES pressure measured 11.4 +/- 3.5 torr. This decreased to 7.8 +/- 2.8 torr immediately after Stamm gastrostomy (P less than .025). When evaluated at 1 and 2 weeks after gastrostomy, further decrease in LES pressures to 6.6 +/- 1.6 torr and 4.8 +/- 1.6 was observed (P less than .02 v preoperative). Three of five cats undergoing barium swallow demonstrated significant reflux radiographically. Stamm gastrostomy caused significant reduction of the LES pressure in all cats studied. This resulted in clinical GER as documented by barium swallow in three of five cats.(ABSTRACT TRUNCATED AT 250 WORDS)

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

Effect of Nissen fundoplication operation on the competence of the lower esophageal sphincter.

The results of Nissen fundoplication operation were evaluated in 12 patients with hiatus hernia and gastroesophageal reflux before and 3, 6, and 12 months after the operation. Excellent clinical results as evidenced by absence of dysphagia, esophagitis, and radiological signs of reflux were obtained in 11 patients. One year after operation one patient developed renewed reflux and slight esophagitis, probably due to sliding of the fundoplication. The resting pressure of the lower esophageal sphincter (LES) increased from 5.4 +/- 5.8 cm H2O (mean +/- S.D.) before the operation to 11.8 +/- 5.0 cm H2O 3 months after operation (p less than 0.01). At 6 and 12 months the mean resting pressure (9.5 +/- 4.6 and 8.0 +/- 3.9 cm H2O, respectively) was not significantly different from the preoperative value. Compared with the preoperative LES pressure after pentagastrin stimulation (10.8 +/- 13.9 cm H2O) the pressure 3 months after operation had increased to 33.6 +/- 11.7 (p less than 0.001), after 6 months to 21.6 +/- 7.0 (0.05 greater than p greater than 0.02, and after 12 months to 22.1 +/- 9.0 cm H2O (0.05 greater than p greater than 0.02). In two patients the stimulated pressure decreased after 6 and 12 months; both are completely free of symptoms. We suggest that assessment of the competence of the LES after fundoplication by pressure measurement is of limited value.

Effect of Nissen Fundoplication on the Lower Esophageal Sphincter Pressure of Children with Gastroesophageal Reflux

Nine children (age range, 5 weeks to 13 years) with gastroesophageal reflux unresponsive to medical management were evaluated with esophageal manometry studies before and after Nissen fundoplications were performed. All patients had a postoperative increase in lower esophageal sphincter (LES) pressure. The mean preoperative LES pressure was 11.3 mm Hg and the mean postoperative pressure was 22.3 mm Hg. The mean LES pressure increase after surgery was 10.9 mm Hg (range: 5.3 to 22.5 mm Hg). All patients ceased vomiting immediately after surgery and have gained weight at a rate greater than that expected for their age.