Lower Esophageal Sphincter Length Research Articles

A retrospective study of 3D measurement and analysis applied in the morphological evaluation of achalasia cardia.

Achalasia cardia (AC) is defined as a disorder of esophageal motility whose diagnostic gold standard depends on high-resolution manometry (HRM). The invasiveness of HRM can cause difficulties in diagnosis, treatment, and follow-up for patients with AC. Thus, we aimed to investigate the function of 3D reconstruction and measurement to prove the wide application of this alternative non-invasive approach for AC. A total of 126 patients with AC and 40 healthy subjects in Tianjin Medical University General Hospital from January 2018 to October 2022 were enrolled in this retrospective study. Chest CT images of these subjects were used to reconstruct the 3D models of the esophagus, stomach, spine, left crus, and right crus. Measurements of esophagus length, volume of esophagus, gastroesophageal insertion angle (His angle), max thickness of esophageal wall, esophagus maximum transverse and longitudinal diameter, esophagus-spine angle, and spine-lower esophageal sphincter (LES) angle were applied based on the models. Retrocardiac esophagus length, volume of esophagus, max thickness of esophageal wall, esophagus maximum transverse and longitudinal diameter, thoracic esophagus-spine angle, and spine-LES angle in the AC group were higher than those in the control group (all P values <0.05). Among the three subtypes of AC, thoracic esophagus length, intra-abdominal LES length, volume of esophagus, His angle, esophagus maximum transverse and longitudinal diameter, and thoracic esophagus-spine angle all presented statistical differences (all P values <0.05). Correlation analysis revealed that manometric types were positively associated with His angle [r=0.196; 95% confidence interval (CI): 0.009, 0.372; P=0.028] but negatively associated with volume of esophagus (r=-0.480; 95% CI: -0.639, -0.310; P<0.001), esophagus maximum transverse diameter (r=-0.551; 95% CI: -0.679, -0.400; P<0.001), esophagus maximum longitudinal diameter (r=-0.518; 95% CI: -0.649, -0.366; P<0.001), and thoracic esophagus-spine angle (r=-0.324; 95% CI: -0.479, -0.157; P<0.001). This study successfully presented the differences in esophageal length, volume, thickness, and angles between healthy subjects and different AC subtypes on the basis of 3D reconstruction and measurement. Thus, 3D model and measurement can be regarded as a good support for further research and make a valuable contribution to developing non-invasive approaches for AC management.

474. MANOMETRIC IDENTIKIT OF A FUNCTIONING AND EFFECTIVE FUNDOPLICATION IN THE HIGH-RESOLUTION MANOMETRY ERA

Abstract Background Assessing patients following Laparoscopic Fundoplication (LF) can be challenging. Functional information provided by pathophysiological testing—which can shed light on the cause of recurrent symptoms—could be key to clinical decision making. The value of performing High-Resolution Manometry (HRM) after LF is still unclear and debated. We sought to establish the HRM parameters indicative of a functioning fundoplication, and whether HRM could distinguish it from a tight or defective one. Methods We studied patients with gastroesophageal reflux disease (GERD) who underwent laparoscopic Nissen (LN) or Toupet (LT) fundoplication between 2010–2022. HRM and pH monitoring were performed before and 6 months after surgery. LF failure was defined as GerdQ score ≥ 8 and abnormal 24 h-pH study or just abnormal 24 h-pH study. The study population was divided into 5 groups: LN and LT patients with normal pH monitoring (LNpH- and LTpH-, respectively); LN and LT patients with pathological pH monitoring (LNpH+ and LTpH+ groups, respectively); and patients with postoperative severe dysphagia (Dysphagia group). The novel Hiatal Morphology (HM) classification was applied, envisaging 3 subtypes: HM1 (normal morphology); HM2 (intrathoracic fundoplication); and HM3 (slipped fundoplication). Results We recruited 132 patients: 46 in the LNpH- group, 51 in the LTpH- group, 15 in the LNpH+ group, 7 in the LTpH+ group, and 5 in the Dysphagia group (Figure 1). Eight patients with GerdQ score ≥ 8 and normal 24 h-pH findings were excluded. At univariate analysis, postoperative lower esophageal sphincter (LES) basal pressure (p = 0.011), total and abdominal LES length (p = 0.014, p &amp;lt; 0.001) were correlated with LF failure. At multivariate analysis, postoperative abdominal LES length (p = 0.001) and HM2 (p &amp;lt; 0.001) were independently associated with surgical failure. Integrated relaxation pressure (IRP) was significantly higher in the Dysphagia group than in the LNpH- group. Conclusion This study generated reference HRM values for an effective LF and confirms that using HRM to assess the abdominal portion of the neo-sphincter and abnormal hiatal morphology (HM2) improves the clinical assessment of recurrent symptoms. HRM can distinguish patients with a well-functioning wrap from those developing recurrent GERD due to an ineffective wrap. Postoperative IRP also correlated significantly with the onset of dysphagia after surgery.

Acupuncture Improved the Function of the Lower Esophageal Sphincter and Esophageal Motility in Chinese Patients with Refractory Gastroesophageal Reflux Disease Symptoms: A Randomized Trial.

Acupuncture is therapeutic for refractory gastroesophageal reflux disease by an unclear mechanism. This study was aimed at investigating the effect of acupuncture on esophageal motility in patients with symptoms of refractory gastroesophageal reflux disease. Sixty-eight patients with refractory gastroesophageal reflux disease symptoms were prospectively enrolled from August 2014 to December 2018 and randomized into acupuncture and control groups (n = 33 and 35, respectively). The acupuncture group received acupuncture, and the control group received sham acupuncture. Pre- and post-acupuncture high-resolution manometry was performed to evaluate the effect of acupuncture on esophageal motility. The GerdQ questionnaire was used to evaluate the pre- and post-intervention symptoms. After acupuncture, there was a significant increase in the length of lower esophageal sphincter (3.10 ± 1.08 cm vs. 3.78 ± 1.01 cm), length of intra-abdominal lower esophageal sphincter (2.14 ± 1.05 cm vs. 2.75 ± 1.16 cm), and mean basal pressure of lower esophageal sphincter (22.02 ± 10.03 mmHg vs. 25.06 ± 11.48 mmHg) in the acupuncture group (P = 0.014); moreover, the numbers of fragmented contraction and ineffective contraction decreased from 36 to 12 (P < 0.001) and 43 to 18 (P = 0.001), respectively, in the acupuncture group. However, no significant difference was observed in the control group. The GerdQ score decreased significantly from 9.45 ± 2.44 to 7.82 ± 2.21 points in the first week after acupuncture (P < 0.001). Acupuncture, which improves esophageal motility, has short-term efficacy in patients with symptoms of refractory gastroesophageal reflux disease. This trial is registered with Chinese Clinical Trial Registry (ChiCTR1800019646).

Exploring objective factors to predict successful outcomes after laparoscopic Nissen fundoplication.

Currently, the reported parameters that predict the resolution of symptoms after surgery are largely subjective and unreliable. Considering that fundoplication rebuilds the structural integrity of the lower esophageal sphincter (LES), the authors focused on searching for objective and quantitative predictors for the resolution of symptoms based on the anatomical issues and whether an antireflux barrier can be well established or not. The authors reviewed the prospectively collected data of 266 patients with gastroesophageal reflux disease (GERD) who had undergone laparoscopic Nissen fundoplication (LNF). All patients were diagnosed with GERD using preoperative esophagogastroduodenoscopy, 24-h ambulatory esophageal pH monitoring, and high-resolution esophageal manometry. The patients received GERD symptom surveys using the validated Korean Antireflux Surgery Group questionnaire twice: preoperatively and 3 months after the surgery. After excluding patients with insufficient follow-up data, 152 patients were included in the analysis. Multivariate logistic regression analyses revealed that a longer length of the LES and lower BMI determined better resolution of typical symptoms after LNF (all P <0.05). Regarding atypical symptoms, higher resting pressure of LES and DeMeester score greater than or equal to 14.7 were associated with better resolution after the surgery (all P <0.05). After LNF, typical symptoms improved in 34 out of 37 patients (91.9%) with a length of LES >greater than .05cm, BMI less than 23.67kg/m 2 , and atypical symptoms were resolved in 16 out of 19 patients (84.2%) with resting pressure of LES greater than or equal to 19.65mmHg, DeMeester score greater than or equal to 14.7. These results show that the preoperative length and resting pressure of LES is important in the objective prediction of symptom improvement after LNF.

Assessment of Esophageal Motility Disorders in Patients With Refractory Gastroesophageal Reflux Disease

There is insufficient data about esophageal body dysmotility in patients with refractory gastroesophageal reflux disease (RGERD) and inadequate response to proton pump inhibitors (PPIs) treatment. This study aimed to assess esophageal motility disorder and reflux parameters among these patients by high-resolution manometry (HRM) and intraluminal impedance and pH (MII‐pH) monitoring after stopping PPI therapy. A retrospective study was conducted among 100 RGERD patients admitted to Taleghani Hospital (Tehran, Iran) for one year. More than half of them were males (55%). Their mean age was 47.10±6.92, and 50% of patients had ineffective esophageal motility (IEM). Middle, distal, and proximal esophageal pressure (MEP, DEP, and PEP), lower esophageal sphincter (LES) basal pressure (LESP), integrated relaxation pressure (IRP), distal contractile integral (DCI), large breaks, upper esophageal sphincter basal pressure (UESP), and LES length (LESL) in IEM patients were significantly lower than the patients with normal esophageal motility (P&lt;0.001). Furthermore, there were more patients in the IEM group with long-term and abnormal weakly acid reflux compared with the non-IEM group (P&lt;0.05). It seems that the evaluation of reflux parameters and esophageal motility could lead to additional insights into the pathophysiological mechanisms of RGERD. Nevertheless, further studies are suggested to evaluate the effects of esophageal motility disorders among RGERD patients.

Analysis of Esophageal Motility and Reflux Characteristics in Patients with Gastroesophageal Reflux Disease With or Without Extraesophageal Symptoms.

The pathogenesis of extraesophageal symptoms of gastroesophageal reflux disease is complex, and esophageal motility and reflux may be involved in it. In this study, we aimed to compare esophageal motility and reflux characteristics in gastroesopha- geal reflux disease patients with and without extraesophageal symptoms by high-resolution manometry and multichannel intraluminal impedance-pH monitoring. We retrospectively studied gastroesophageal reflux disease patients between January 2014 and December 2018. All patients had undergone high-resolution manometry and multichannel intraluminal impedance-pH monitoring. The results were compared and analyzed. A total of 59 patients were included in this study. Patients were divided into 3 groups according to their main complaint: only typical symptoms (group A, n = 11), both typical and extraesophageal symptoms (group B, n = 33), and only extraesophageal symp- toms (group C, n = 15). Compared with group A, the lower esophageal sphincter basal pressure, integrated residual pressure, and lower esophageal sphincter length were lower, and the proximal reflux percentages of a weak acid and non-acid reflux were higher in group B and group C (P < .017). The positive rate of esophageal motility disorders was lower in group A than in other groups (P < .05). The propor- tion of patients with multiple rapid swallows/single swallow-distal contractile integral ratio greater than 1-was higher in group A than in other groups (P < .05). Decreased lower esophageal sphincter pressure and lower esophageal sphincter length, increased proximal esophageal reflux of weak acid and non-acid reflux, esophageal motility disorders, and decreased peristaltic reserve are involved in the pathogenesis of extraesophageal symptoms of gastroesophageal reflux disease.

S969 Prospective Comparison of Functional Lumen Imaging Probe and High Resolution Esophageal Manometry to Assess Clinical Response After Per-Oral Endoscopic Myotomy

Introduction: Per oral endoscopic myotomy (POEM) has become the standard of care for management of achalasia and esophagogastric junction (EGJ) outlet obstruction (EGJOO). Post-POEM outcomes may be assessed clinically by the Eckardt score (ES) or objectively high-resolution manometry (HRM) and functional lumen imaging probe (FLIP). There are limited data comparing HRM with FLIP to evaluate clinical response (CR) after POEM. Methods: Patients between 2015 and 12/2019 who underwent POEM for achalasia or EGJOO and at least 6 months follow up were identified. Exclusion criteria: Baseline ES < 3 or IRP< 15mmHg and follow-up >6 months but no HRM, FLIP or ES assessment made. Baseline evaluation: EGD, HRM and (beginning in 2016) FLIP of the EGJ to measure EGJ distensibility index (EGJ-DI). POEM included myotomy with extension 2-3 cm into the cardia. Esophageal width was measured from a post-POEM esophagram by a radiologist. Patients returned 6 months post-POEM for repeat EGD, FLIP and HRM. ES was calculated at baseline and 6 months after POEM. CR was defined by three independent metrics: a) ES ≤3; b) EGJ-DI >2.8 mm2/mmHg at any distention 20-50mls and; c) IRP< 15mmHg. ROC curves were constructed and AUC was used to compare the relative performance of the 3 metrics. Results: 118 consecutive patients (60% male, mean 54±17 yrs.) were included. Mean ES and IRP were 8±1.8 and 31.9±13.1 mmHg respectively. Type 2 achalasia was present in 70.3% and previous EGJ therapy was performed in 47.5%. Type 1 had a shorter mean LES length (p=0.003), wider esophagus (p< 0.001) and higher EGJ-DI at 20ml (p=0.04) and 30ml (p=0.042). Type 3 patients had a longer myotomy (p< 0.001). The groups were otherwise similar. Overall CR by ES, IRP and EGJ-DI were 94.9%, 86.4%, and 94.9%, respectively. A normal post-POEM IRP and EGJ-DI had a sensitivity and specificity of 87.5% and 33.3% and 94.6% and 0%, respectively to predict a post-POEM ES≤ 3 (p=0.472 comparing AUCs). In 23 patients with post-POEM ES< 3, EGJ-DI alone (n=5), IRP alone (n=11) or both (n=7) incorrectly predicted no clinical response by ES. A normal post-POEM EGJ-DI had a sensitivity and specificity of 97.1% and 18.8% to predict a normal post-POEM IRP. Conclusion: For patients with achalasia or EGJOO, a normal IRP and EGJ-DI at least 6 months after POEM show excellent sensitivity, poor specificity but are equivalent to evaluate for a normal post-POEM ES. FLIP is an acceptable alternative to HRM to evaluate the LES after POEM in these patients.Table 1.: Comparison of Normalized Integrated Relaxation Pressure (IRP) and Functional Lumen Imaging Probe (FLIP) Distensibility Index to Predict Eckardt Score Response at least 6 months after POEM in 118 Consecutive Patients with Achalasia and EGJOO

Impact of laparoscopic sleeve gastrectomy on esophageal physiology.

Introduction. Laparoscopic sleeve gastrectomy (LSG) is a popular weight loss surgery technique, but the impact on esophageal physiology and esophagogastric junction is still debatable. The aim of our study was to evaluate the manometric changes of the lower esophageal sphincter (LES) after LSG in order to indicate LES manometry pre- procedure. Methods. In a prospective study we evaluated clinically, with upper gastrointestinal endoscopy, and high-resolution esophageal manometry 45 morbidly obese patients before, and 6-12 months after LSG. Results. The BMI (body mass index) decreased from 46.28±5.79 kg/m2 to 32.28±4.65 kg/m2 postoperatively (p <0.01), with a reduction of ~14 kg/m2 of BMI, 39.9 (±11.9) kg body weight and 29.9 (± 6.2)% of the TWL (Total Weight Loss index), in a median interval of 7.9 months. Gastroesophageal reflux disease (GERD) prevalence increased from 17.8% to 31.1% postoperatively, with new GERD onset in 22.2%, but mild symptomatology (the median GERD-HRQL score increased from 1.56 to 2.84 points). Postoperatory reflux was associated with lower esophageal sphincter (LES) hypotonia, shortening of LES length and IIGP (increased intragastric pressure). Hiatal hernia repair rate was 17.8%, and proton pump inhibitor consumption 20%. After weight loss, the 10 cases of esophagitis discovered preoperatively cured, but 3 patients were diagnosed with de novo esophagitis. The prevalence of manometric dysmotility after LSG was 28.9%, lower than before surgery (44.4%). Conclusion. Even if GERD remains the main limitation of LSG, the high-resolution esophageal manometry has proved useful and should be implemented in morbidly obese evaluation protocol, to better select the bariatric procedure.

Pressure and length of the lower esophageal sphincter as predictive indicators of therapeutic efficacy of baclofen for refractory gastroesophageal reflux-induced chronic cough

BackgroundTherapeutic efficacy of baclofen is suboptimal in the treatment of refractory gastroesophageal reflux-induced chronic cough (GERC). The purpose of the study is to identify its therapeutic predictors in a prospective clinical study. Methods138 patients with suspected refractory GERC were treated with baclofen. Before the therapy, all the patients underwent esophageal manometry and multichannel intraluminal impedance-pH monitoring to establish the diagnosis. After the efficacy of baclofen was evaluated, a stepwise logistic regression analysis was performed to identify the therapeutic predictors of baclofen and to establish a regression prediction model. ResultsThe overall response rate of baclofen treatment was 52.2% (72/138). The lower esophageal sphincter pressure (LESP) (odds ratio (OR) = 0.592, P = 0.000) and lower esophageal sphincter length (LESL) (OR = 0.144, P = 0.008) were independent predictors of baclofen efficacy. The optimal cut-off point to predict baclofen efficacy for LESP was 11.00 mmHg, with a sensitivity of 83.7% and specificity of 79.1% while that for LESL was 2.35 cm, with a sensitivity of 81.6% and specificity of 72.1%. The highest predictive specificity (90.7%) was achieved when both LESP and LESL were jointly used. ConclusionsLESP and LESL may be used to screen the patients with refractory GERC suitable for baclofen therapy and help improve the therapeutic precision. Clinical trial registrationChiCTR- ONC-13003123.

Characteristics of esophageal motility and clinical presentation in gastroesophageal reflux disease patients of different age groups

Objective: To explore the characteristics of esophageal motility and clinical presentation in gastroesophageal reflux disease (GERD) patients of different age groups. Methods: This was a case-control study. Confirmed GERD patients in the Department of Gastroenterology of Peking Union Medical College Hospital from January 2015 to September 2018 were enrolled and divided into two groups: elderly group (≥60 years old) and young and middle-aged group (<60 years old). Characteristics of gender, disease course, clinical symptoms, esophageal motility, gastroscopic manifestations and esophageal hiatus function of patients in the two groups were analyzed. Results: A total of 250 patients met the inclusion criteria, with 61 patients in elderly group and 189 in young and middle-aged group. There were no significant differences in gender ((male/female: 24/37 vs 78/111, P>0.05) and disease course((4.9±4.2) years vs(4.5±3.8)years, P>0.05) between the two groups. However, there were significant differences in typical symptoms (acid regurgitation and heartburn) and atypical symptoms (chest pain, cough, foreign body sensation in pharynx, etc.) (typical/atypical symptoms: 35/26 vs 146/43, P<0.01) between the two groups. Compared with young and middle-aged group, upper esophageal sphincter (UES) resting pressure was lower ((65±28) mmHg (1 mmHg=0.133 kPa)vs (74±28) mmHg, P<0.05), but the percentage of ineffective esophageal motility (IEM) (78.7%(48/61) vs 65.1%(123/189),P<0.05) and DeMeester score (16.3(6.0,36.3) vs 6.4(2.5,18.0), P<0.05) were higher in elderly group. There were no significant differences in lower esophageal sphincter (LES) resting pressure and distal contractile integral (DCI) between the two groups. Higher proportion of grade C and D reflux esophagitis,and grade C and D reflux esophagitis complicated with esophageal hiatus dysfunction was observed in elderly group compared with young and middle-aged group (2.04%(8/49) vs 0.65%(1/155); 14.29%(7/49) vs 0(0/155); both P<0.01). Pearson correlation analysis showed that there was a negative correlation between UES resting pressure and age(r=-0.145, P<0.05), while there was a positive correlation between the LES length and age (r=0.129, P<0.05). Conclusion: Compared with young and middle-aged GERD patients, the atypical symptoms, lower LES resting pressure, increased incidence of ineffective esophageal motility and acid exposure were more prominent in the elderly. Considering that anti-reflux function was weakened, long-term acid suppressants may be needed in elderly patients.

S0414 A Predictive Model for LES Location Independent of Manometry

INTRODUCTION: In current practice, multichannel intraluminal impedance (MII)/pH testing must be preceded by manometry to determine LES location for accurate placement of the impedance catheter. However, when solely used to localize LES for MII placement, manometry adds increased cost, time, and patient dissatisfaction without clinical value. A non-invasive predictive model for LES location based on clinical demographics could obviate the need for manometry. We aimed to create a pragmatic, predictive model for LES location based on routine clinical parameters. METHODS: A retrospective chart review was performed on patients who underwent esophageal manometry from 2007–2018 at a single, tertiary medical center. Pre-selected variables of baseline demographics were evaluated in correlation with manometric parameters of proximal LES location, LES length, esophageal length, presence and size of hiatal hernia. Multivariable linear regression was used to estimate the association between predictors and proximal LES location. Spearman's rank correlation was used to determine potential predictive power to prevent overfitting (Figure 1). Missing data on predefined variables was minimal; for missing covariates multiple imputations was used. RESULTS: 465 patient records were analyzed. Proximal LES location ranged from 29–51 cm. Height and gender were the most important predictors of LES location (P < 0.001). Height increased distance to LES location by 2 cm for every 15 cm increase in height. Male gender predicted an increased distance to LES location by 2cm. Age and weight had no significant impact on LES location. The predictive equations for LES location were 18.7 + 0.136*height (males) and 17.2 + 0.154*height (females) (Figure 2). CONCLUSION: This is the first predictive model for LES location using readily-accessible, non-invasive patient characteristics of height and gender. This simple, pragmatic model prevents the need for costly, invasive manometry and allows accurate location of the LES. Future studies are ongoing for prospective validation.Figure 1.: Prediction coefficients and association of clinical parameters on LES location as calculated by multivariable linear regression. (Significance at P < 0.01).Figure 2.: Prediction Model: Predicted LES location as function of height and gender. (LES, Lower Esophageal Sphincter).

203 RISK AND PROTECTIVE FACTORS OF GASTROESOPHAGEAL REFLUX DISEASE AFTER PERORAL ENDOSCOPIC MYOTOMY

Abstract Peroral endoscopic myotomy(POEM)has been reported as safe and effective treatment for achalasia. This procedure is proposed to be a less invasive alternative to conventional laparoscopic Heller-myotomy with Dor-fundoplicatin(LHD), previous studies have shown that POEM may result in a higher incidence of gastroesophageal reflux disease(GERD)compared with LHD. However, certain predictors of GERD after POEM remain unstudied limiting current treatment strategy of achalasia. The aim of this study is to clarify the protective factors of GERD post-POEM. Methods Fifty-one patients who underwent POEM at our institution between January 2016 and December 2019 were included. We performed esophagogram and high-resolution esophageal manometry (HRM) as a part of preoperative evaluation. Upper gastrointestinal endoscopy has been assessed 3 months, 1 year, and then yearly after POEM. Patients were divided into two groups based on post-POEM endoscopic findings: GERD group (patients who had esophagitis [n = 28; median age 53 years with 18 male]) and non-GERD group (patients who did not have GERD [n = 23; median age 50 years with 14 male]). We compared preoperative foregut tests between the two groups. Results Twenty-eight out of 51 patients (54.9%) developed esophagitis. There were no differences in age, sex, BMI, and findings of esophagogram between the groups. Based on HRM test, greater overall lower esophageal sphincter (LES) length was noted in the non-GERD group compared with the GERD group (3.0 vs. 2.6 cm, p = 0.034). Length of gastric myotomy was comparable between the GERD and non-GERD groups (2.0 vs. 3.0 cm, p = 0.477). Similar incidence of esophagitis was evident in patients who had a history of prior LHD and those who underwent POEM as a primary intervention (60% [9/15 patients] vs. 52.8% [19/36 patients], p = 0.437). Conclusion Shorter overall LES length appears to be associated with esophagitis post-POEM. Length of gastric myotomy did not correlate to GERD in the study cohort. Prior Dor fundoplication may not avert development of GERD after POEM. Further study is warranted.

Simple Manometric Index for Comprehensive Esophagogastric Junction Barrier Competency Against Gastroesophageal Reflux

The esophagogastric junction (EGJ) is an anatomic and physiologic barrier against gastroesophageal reflux. Comprehensive evaluation of EGJ barrier parameters using high-resolution manometry in patients with GERD has not been well established. We propose a simple index for comprehensive EGJ antireflux competency. Patients who underwent high-resolution manometry and 24-hour pH monitoring between January 2017 and September 2018 were included. Of these, patients with normal esophageal motility were selected. EGJ antireflux competency was assessed based on the following 3categories: anatomic configuration of the EGJ complex (ie EGJ morphology), backflow-preventive pressure on the lower esophageal sphincter (LES) (ie LES pressure integral), and backflow-promotive pressure across the LES (ie thoracoabdominal pressure gradient). Each category was scored on a scale of 0 to 2, applying clinically meaningful divisions, and a cumulative score was calculated (EGJ index: 0 to 6 points). DeMeester score > 14.72 indicated GERD. In total, 259 patients met study criteria. Of these, GERD was noted in 109 patients (42.1%). The pH parameters were gradually exacerbated, depending on the EGJ index. Good correlations were seen between EGJ index and previously proposed parameters for EGJ disruption, including LES length, LES pressure, and LES pressure integral (area under the curve > 0.9 [excellent validation]). No patient had GERD if the EGJ index score was 0. However, GERD was seen in as high as 85.7% of patients with the highest score of6. EGJ disruption severity was clearly graded based on a simple scoring method, which can improve evaluation and development of clinical strategies for GERD.

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.

Upper Esophageal Sphincter Motility and Thoracic Pressure are Determinants of Pressurized Waves in Achalasia Subtypes According to the Chicago Classification.

Phenotypes of achalasia are based on esophageal body pressurization during swallow. The reasons that lead to pressurized waves are still unclear. This study aims to evaluate manometric parameters that may determine pressurized waves in patients with achalasia. A total of 100 achalasia high-resolution manometry tests were reviewed. We measured before each swallow: upper esophageal sphincter (UES) basal pressure, esophageal length, lower esophageal sphincter (LES) basal pressure, LES length, gastric and thoracic pressure, transdiaphragmatic pressure gradient and the LES retention pressure (LES basal pressure-TPG); during swallow: UES pressure, UES residual pressure, UES recovery time, LES relaxation pressure, gastric and thoracic pressure, transdiaphragmatic pressure gradient and after swallow: esophageal length, LES length, wave pressure, gastric and thoracic pressure and transdiaphragmatic gradient pressure. Univariate analysis showed in pressurized waves before swallow: higher thoracic, UES and LES basal pressure, longer LES length and decrease in LES retention pressure; during swallow: higher thoracic, gastric and UES pressure, higher UES and LES relaxation pressure and after swallow: higher thoracic and gastric pressure. Multivariate analysis in pressurized waves showed as significant before swallow: thoracic and UES basal pressure; during swallow: thoracic, gastric and UES pressure, UES residual pressure and UES recovery time and after swallow: thoracic pressure. Basal esophageal pressurization and the UES are independent variables that may be associated with pressurized waves.

Study on esophageal motility and anti-reflux barrier function in patients with heartburn symptom and negative endoscopic findings based on Rome IV criteria

Objective To evaluate esophageal motility and anti-reflux barrier function in patients with different phenotypes of heartburn and negative endoscopic findings based on the Rome Ⅳ criteria. Methods From March 2011 to November 2018, 136 patients with heartburn and negative endoscopic findings were retrospectively analyzed. The patients underwent high-resolution manometry (HRM), 24-hour pH monitoring and proton pump inhibitor (PPI) test and according to the Rome Ⅳ criteria and new diagnostic procedures, they were divided into non-erosive reflux disease (NERD) group, reflux hypersensitivity (RH) group, functional heartburn (FH) group and unclassified group. During the same period, 20 healthy volunteers were selected as healthy control group. The changes of esophageal motility and HRM were analyzed among different groups. Statistical analysis was performed using one-way analysis of variance, Kruskal-Wallis H test and chi-square test. Results According to Rome Ⅳ criteria, 35 patients were enrolled into the NERD group, 43 patients were enrolled into the RH group, 48 patients were included in the FH group, and 10 patients were enrolled into unclassified group. There were no significant differences between the NERD group, the RH group, the FH group, the unclassified group and healthy control group in the length of the lower esophageal sphincter (LES), end lower esophageal sphincter resting pressure (LESP), mean LESP, 4-second-integrated relaxation pressure (4 s-IRP), distal latency (DL) , upper esophageal sphincter residual pressure (UES-RP), upper esophageal sphincter relaxation time to nadir, upper esophageal sphincter (UES) recovery time and esophagogastric junction contractile integral (EGJ-CI, all P>0.05). The distal contractile integral (DCI) of NERD group and unclassified group were both lower than that of healthy control group (919.7 mmHg·s·cm (411.7, 1 417.9) mmHg·s·cm (1 mmHg=0.133 kPa), 535.6 mmHg·s·cm (321.4, 1 513.4) mmHg·s·cm vs. 1 322.1 mmHg·s·cm (841.6, 1 918.5) mmHg·s·cm), and the differences were statistically significant (Z=-2.62 and -2.20, P=0.01 and 0.03). The upper esophageal sphincter pressure (UESP) of the unclassified group was lower than that of the healthy control group(57.0 mmHg (31.3, 77.8) mmHg vs. 70.4 mmHg (49.4, 97.8) mmHg), and the difference was statistically significant (Z=-2.64, P=0.02). There was significant difference in esophagogastric junction (EGJ) subtypes between the NERD group, the RH group, the FH group and the unclassified group (χ2=10.85, P=0.02); the proportion of type Ⅲ patients was highest in unclassified group, followed by NERD group, which were both higher than those of RH group and FH group. There was no significant difference in the proportion of esophageal motility subtypes between NERD group, RH group, FH group and unclassified group (P>0.05). Conclusions Patients with different phenotypes of heartburn and negative endoscopy finding should be classified by efficient diagnostic procedure according to the Rome Ⅳ criteria combined with HRM, 24-hour pH monitoring and PPI test. The unclassified patients need further evaluation, especially for those with effective PPI test and negative pH monitoring. However, the evaluation of anti-reflux barrier function by the HRM parameters in patients with heartburn and negative endoscopic findings has certain limitations. Key words: Heartburn; Esophageal pH monitoring; Non-erosive reflux disease; Reflux hypersensitivity; Manometry; Rome Ⅳ

P173 HIGH-RESOLUTION MANOMETRIC FINDINGS AFTER MAGNETIC SPHINCTER AUGMENTATION

Abstract Aim The aim of this study was to evaluate esophageal motility before and after Magnetic Sphincter Augmentation (MSA) for medically refractory Gastro-Esophageal Reflux Disease (GERD). Background and Methods MSA (LINX® Reflux Management System) is intended for patients with chronic GERD with incomplete symptom relief from proton-pump inhibitors (PPI) and abnormal acid exposure. A prospectively collected database of patients who underwent MSA between 2007 and 2019 was queried. All patients who completed pre- and post-operative high-resolution manometry (HRM) were included in the study. Additional investigations included Health-Related Quality of Life (GERD-HRQL) questionnaire, Functional Outcome Swallowing Scale (FOSS), upper gastrointestinal endoscopy, barium swallow, and 24-96 hours pH-study. Data were analyzed using Wilcoxon signed rank test and McNemar test. Results Forty-five patients met the inclusion criteria. The median follow-up was 10 months (IQR 6). Compared to baseline, there was a statistically significant reduction in PPI use (p=0.000), rate of heartburn (p=0.000), regurgitation (p=0.008), and extra-esophageal symptoms (p=0.000). Only three (6.7%) patients required dietary changes. The GERD-HRQL score significantly improved (p=0.000). There was a significant increase in the Lower Esophageal Sphincter (LES) competency, including LES length (p=0.004) and Esophago-gastric Contractile Integral ((EGJ-CI) (p=0.000). A significant increase in integrated relaxation pressure (IRP) (p=0.000), mean Distal Contractile Integral (DCI) (p=0.008) and intrabolus pressure (p=0.000) was also found. Thirteen (28.9%) patients presented pre-operative Ineffective Esophageal Motility (IEM) and five of them resolved postoperatively. Two patients (4.4%) developed IEM after surgery: both had IRP and DCI values within normal limits, and one of them complained of dysphagia. However, the GERD-HRQL score recovered in both patients. Conclusion MSA was clinically effective in relieving both typical and atypical GERD symptoms. LES competency increased after MSA. EGJ outflow obstruction was uncommon and not associated with symptoms. Finally, ineffective esophageal motility may reverse to normal after MSA.

The relationship between gastroesophageal junction integrity and symptomatic fundoplication outcomes

The majority of patients who undergo a laparoscopic fundoplication for gastroesophageal reflux disease (GERD) have a structural (hiatal hernia, shortened lower esophageal sphincter [LES]) or functional (weak LES) defect of the gastroesophageal junction (GEJ). We hypothesized that the symptomatic outcomes of fundoplication in patients with a competent GEJ prior to surgery are inferior to those with an incompetent GEJ. This is a retrospective review of prospectively maintained data on subjects who underwent primary laparoscopic fundoplication (Nissen or Toupet) for medically refractory and confirmed GERD. Three esophageal manometry variables were used to determine GEJ competency: (1) hiatal hernia (normal = no hernia), (2) total lower esophageal sphincter length (normal ≥ 2.43cm), and (3) lower esophageal sphincter pressure (normal = 15.0-43.7mmHg). Patients in the competent group had normal values for all 3 variables. Symptomatic outcomes were assessed with the GERD Health-Related Quality of Life (HRQL) survey administered pre- and postoperatively, and then compared both intragroup, intergroup, and by procedure. A total of 78 patients met inclusion criteria-17 competent GEJ and 61 incompetent GEJ patients. GERD-HRQL scores improved in the incompetent cohort at all intervals out to 2years postoperatively. GERD-HRQL improved in the competent cohort at 2months, with no difference at 6months or 2years postoperatively compared to preoperative scores. Competent GEJ patients receiving a Nissen fundoplication had a higher rate of additional procedures (endoscopy with or without dilation, pH studies) following surgery to address recurrent or persistent GERD symptoms compared to Toupet. GERD patients with a competent GEJ report a lower GERD-HRQL with more frequent and severe reflux symptoms up to 2 years post-fundoplication. Competent GEJ patients receiving a Nissen fundoplication are more likely to have additional procedures to address symptoms following surgery. Surgeons should approach patients with a competent GEJ and medically refractory GERD with caution.

Clinical features and esophageal motility characteristics of patients with esophagogastric junction outflow obstruction

Objective To analyze the clinical features and esophageal motility characteristics of patients with esophagogastric junction outflow obstruction (EGJOO). Methods From January 2015 to January 2018, at Affiliated Hospital of Zunyi Medical College, the clinical data of 663 outpatients with various gastrointestinal symptoms were collected. Gastroscopy and esophageal high resolution manometry (HRM) were performed to exclude gastrointestinal organic lesions. The 120 patients were divided into EGJOO group (71 cases) and non-EGJOO group (49 cases). Furthermore, according to integrated relaxation pressure (IRP) the 71 EGJOO patients were divided into mild group (41 cases), moderate group (20 cases) and severe group (10 cases). Independent sample t test and one-way analysis of variance were performed for statistical analysis. Results Among 71 EGJOO patients, 43.7% (31/71) showed post sternal heartburn or acid regurgitation, 32.4% (23/71) showed obstruction or dysphagia, 21.1% (15/71) showed chest pain, 21.1% (15/71) showed other atypical symptoms such as hiccups and bloating, and 5.6% (4/71) showed upper abdominal pain. The IRP, lower esophageal sphincter (LES) length, LES resting pressure and intrabolus pressure (IBP) of the EGJOO group were higher than those of the non-EGJOO group ((18.24±3.07) mmHg (1 mmHg=0.133 kPa) vs. (10.92±2.37) mmHg, (3.47±0.85) cm vs. (3.11±0.80) cm, (32.33±9.11) mmHg vs. (21.31±6.55) mmHg, (6.22±3.74) mmHg vs. (4.69±2.68) mmHg), and the differences were statistically significant (t=-13.947, -2.303, -7.706 and -2.626; all P<0.05). The LES relaxation rate and distal contractile integral (DCI) of the EGJOO group were lower than those of the non-EGJOO group ((44.03±9.86)% vs. (53.86±11.33)%, (1 410.13±794.23) mmHg·s·cm vs. (1 741.86±894.16) mmHg·s·cm), and the differences were statistically significant (t=5.046 and 2.136, both P<0.05). The LES resting pressure of the mild group was higher than that of the moderate group ((30.76±9.23) mmHg vs. (29.69±5.87) mmHg); the LES resting pressure of the moderate group was lower than that of the severe group ((29.69±5.87) mmHg vs. (42.02±9.23) mmHg); and the differences were statistically significant (both Tamhane test, P=0.012 and 0.011). The IBP of the mild group was lower than that of the moderate group and the severe group ((5.16±3.41) mmHg vs. (8.02±2.58) mmHg and (7.46±3.48) mmHg), and the differences were statistically significant (both least-significant difference test, both P<0.05). The DCI of the mild group was lower than that of the moderate group ((1 241.41±606.12) mmHg·s·cm vs. (1 438.55±644.74) mmHg·s·cm), and the difference was statistically significant (Tamhane test, P=0.011). Conclusions Heartburn, acid reflux and dysphagia are common clinical symptoms in EGJOO patients. The weaker the peristalsis of the esophageal body of EGJOO patients, the more obvious of dysphagia. Increased IBP is an indirect manifestation of esophagogastric junction relaxation disorder. Key words: Esophagogastric junction outflow obstruction; Esophageal motility; Clinical characteristics; High resolution manometry

Relationship between the severity of reflux esophagitis and the esophageal motility features on high resolution manometry

Objective: To analyze esophageal motility dysfunction in gastroesophageal reflux disease (GERD) with different severity of esophagitis, and the relationship between the esophageal motility dysfunction and the severity of esophagitis. Methods: GERD patients simultaneously undergone endoscopy and high-resolution manometry were divided into four groups: Non-esophagitis (Non-erosive gastroesophageal reflux disease, NERD) group, mild esophagitis group, moderate esophagitis group and severe esophagitis group. The gender and age were matched for each group, and every group consisted of 80 cases. Nonparametric test was used to analyze the differences in HRM parameters, such as upper esophageal sphincter (UES) pressure, lower esophageal sphincter (LES) pressure, LES length, LES-CD (crural diaphragm) separation distance, and the percentage of failed peristalsis of the four groups, and the differences between each two of the groups were also analyzed. Results: Nonparametric test showed that the LES pressure and length decreased with the severity of esophagitis, and there were statistical differences (P<0.001, P=0.030). The failed peristalsis percentage increased with the severity of esophagitis and the difference was statistically significant (P<0.001). The LES-CD separation distance was increased with the severity of esophagitis and had statistically significance (P<0.001). When comparing the differences between each two of the groups, there were significant differences (P<0.001, P=0.012, P<0.001, P<0.001) between NERD group and severe esophagitis group in the HRM parameters of the lower esophageal sphincter pressure, the LES length, the LES-CD separation distance, and the percentage of ineffective swallowing in the NERD and severe esophagitis group. The detection rate of HH was significantly increased from NERD to severe esophagitis, the detection rate of HH was 6.3% to 82.5% in gastoracopy and 16.3% to 45.0% in HRM, and the diagnostic consistency was fair (Kappa Value: 0.31). Conclusions: Hypo-dynamic state of esophageal and HH are the main motility characteristics of erosive gastroesophageal reflux disease, Esophageal motility abnormalities increase in parallel with the severity of GERD from NERD to severe esophagitis, these motility disorders may also play important roles in causing esophagitis.