Abnormal structure and function of the esophagogastric junction and proximal stomach in gastroesophageal reflux disease

Oesophageal fluoroscopy in adults-when and why?

Oesophageal fluoroscopy is a radiological procedure that uses dynamic recording of the swallowing process to evaluate morphology and function simultaneously, a characteristic not found in other clinical tests. It enables a comprehensive evaluation of the entire upper gastrointestinal tract, from the oropharynx to oesophagogastric bolus transport. The number of fluoroscopies of the oesophagus and the oropharynx has increased in recent decades, while the overall use of gastrointestinal fluoroscopic examinations has declined. Radiologists performing fluoroscopies need a good understanding of the appropriate clinical questions and the methodological advantages and limitations to adjust the examination to the patient's symptoms and clinical situation. This review provides an overview of the indications for oesophageal fluoroscopy and the various pathologies it can identify, ranging from motility disorders to structural abnormalities and assessment in the pre- and postoperative care. The strengths and weaknesses of this modality and its future role within different clinical scenarios in the adult population are discussed. We conclude that oesophageal fluoroscopy remains a valuable tool in diagnostic radiology for the evaluation of oesophageal disorders.

Unveiling the effects of key factors in enhancing gastroesophageal reflux: A fluid-structure analysis before and after laparoscopic sleeve gastrectomy

BACKGROUND AND OBJECTIVES

Gastro-oesophageal reflux disease (GERD) consists in the passage of gastric acid content from the stomach to the oesophagus, causing burns and deteriorating the quality of life. Laparoscopic Sleeve Gastrectomy (LSG) could induce de novo GERD and worsen pre-existing GERD because of the higher gastric pressurisation, reduction of stomach volume and a wider His-angle. In the proposed work, various computational gastric 2D models were developed to understand the effects of variables such as the His-angle, the antral dimension, and the bolus viscosity on the reflux increase.

METHODS

Fluid-Structure Interaction (FSI) computational models which couple the solid mechanics of the gastric wall, and the fluid domain of the bolus, have been developed to shed light on biomechanical aspects of GERD after LSG. A closure was imposed to the lower oesophageal sphincter (LES) mimicking what happens physiologically after food intake.

RESULTS

Results showed that the configuration prone to higher reflux flow was the post-surgical 65° model with a staple line starting directly from the pylorus without antral preservation, for all considered viscosities. Increasing viscosity, reflux flow decreased. Post-surgical refluxes were higher than pre-ones and decreased with increasing antrum preservation.

CONCLUSIONS

These results could be a starting point for analysis of anatomical features, bariatric surgery and GERD occurrence. Further studies based on 3D geometries need to be performed.

Dietary factors involved in GERD management

Gastroesophageal reflux disease (GERD) is extremely common, and even modest weight gain has been associated with higher symptom burden as well as objective evidence of reflux on endoscopy and physiological measurement. Certain trigger foods, especially citrus, coffee, chocolate, fried food, spicy food and red sauces are frequently reported to worsen reflux symptoms, although hard evidence linking these items to objective GERD is lacking. There is better evidence that large meal volume and high calorie content can increase esophageal reflux burden. Conversely, sleeping with the head end of the bed raised, avoiding lying down close to meals, sleeping on the left side and weight loss can improve reflux symptoms and objective reflux evidence, especially when the esophagogastric junction 'reflux barrier' is compromised (e.g., in the presence of a hiatus hernia). Consequently, attention to diet and weight loss are both important elements of management of GERD, and need to be incorporated into management plans.

Preoperative Assessment of Patients Undergoing Bariatric Sleeve Gastrectomy: A Cross-Sectional Study

Introduction. Saudi Arabia (SA) is one of the top countries in the world when it comes to the number of bariatric procedures performed each year. There is still some debate on whether to do regular or selective upper endoscopy during the preoperative examination. The purpose of this study was to explore various endoscopic findings and Helicobacter pylori (HP) infection in symptomatic and asymptomatic patients having laparoscopic sleeve gastrectomy (LSG) prior to surgery. Methods. We investigated a cohort of 132 patients referred to the endoscopy unit from the bariatric surgery outpatient clinic for prebariatric esophagogastroduodenoscopy (EGD) as a part of preoperative LSG. Data extraction from medical records included clinical data such as body mass index (BMI), gastrointestinal symptoms (that include heartburn, regurgitation, epigastric pain, and nausea), medical comorbidities, and laboratory investigations. It included data about the endoscopic findings of EGD procedure as esophageal, gastric, and duodenal findings results as well as the results of biopsy specimens that were taken. Results. Out of 132 patients, 29 (22%) had a BMI of less than 40 kg/m2 whereas 103 (78%) had a BMI of 40 kg/m2 or above, with an average of $44.4\pm 6.4$  kg/m2. The average age of participants was $33.6\pm 10.4$ years. HP was detected in 36 patients (35.0%) with a slightly greater prevalence in patients with a higher BMI (33.7%) than in patients with lower BMI (35.0%). Collectively, 73 patients (55.7%) had positive endoscopic findings of various grades, sites, and combinations. Incompetent cardia (35.6%) was the most often seen esophageal finding, antral gastritis (34.1%) was the most frequently encountered gastric finding, and duodenitis 1st part was the commonest duodenal endoscopic finding (7.8%). Among asymptomatic patients, incompetent cardia was detected in 33.3%, antral gastritis was found in 30.1%, and around one-quarter of them were positive on HP testing (26.6%). Additionally, 16.1% of them had signs of reflux esophagitis, 17.2% had hiatal hernia, and 14.0% had nodular gastritis. Conclusion. The current study revealed a high prevalence of positive endoscopic findings as well as HP infection upon routine endoscopic examination among patients undergoing bariatric surgery even those who were asymptomatic from any gastrointestinal symptoms.

Pathophysiology of Pediatric Gastroesophageal Reflux Disease: Similarities and Differences With Adults

Gastroesophageal reflux (GOR) is defined as "the passage of gastric contents into the esophagus with or without regurgitation and vomiting" and gastroesophageal reflux disease (GORD) is defined "when GOR leads to troublesome symptoms affecting the daily functioning and/or complications." This definition was first developed in 2006 by the Montreal consensus group (1) and later on adopted by pediatric gastroenterology societies such as ESPGHAN and NASPGHAN in 2009 (2). The definition of gastroesophageal reflux reveals little about its pathophysiology and is focused on symptomatology. In this way, it acts as an umbrella term for the multifactorial causes of the disease and the various phenotypes encountered; from functional heartburn to hypersensitive esophagus and nonerosive reflux disease, to erosive esophagitis and Barrett's esophagus. This article is devoted to the pathophysiology of pediatric GORD in comparison to adult GORD and is divided in 2 parts. In the first part, we will systematically describe the different mechanisms for the generation and clearance of reflux events, while on the second part we will discuss the mechanisms involved in symptoms generation. Finally, we will discuss the similarities and differences between pediatric and adult GORD.

Assessment of esophagogastric junction morphology by dynamic real-time MRI: comparison of imaging features to high-resolution manometry

Purpose

To assess the esophagogastric junction (EGJ) on real-time MRI and compare imaging parameters to EGJ morphology on high-resolution manometry (HRM).

Methods

A total of 105 of 117 eligible patients who underwent real-time MRI and high-resolution manometry for GERD-like symptoms between 2015 and 2018 at a single center were retrospectively evaluated (male n = 57; female n = 48; mean age 52.5 ± 15.4 years). Real-time MRI was performed at a median investigation time of 15 min (1 frame/40 ms). On HRM, EGJ morphology was assessed according to the Chicago classification of esophageal motility disorders. Real-time MRI was performed at 3 T using highly undersampled radial fast low-angle shot acquisitions with NLINV image reconstruction. A 10 mL pineapple juice bolus served as oral contrast agent at supine position. Real-time MRI films of the EGJ were acquired during swallowing events and during Valsalva maneuver. Anatomic and functional MRI parameters were compared to EGJ morphology on HRM.

Results

On HRM, n = 42 patients presented with EGJ type I (40.0%), n = 33 with EGJ type II (31.4%), and n = 30 with EGJ type III (28.6%). On real-time MRI, hiatal hernia was more common in patients with EGJ type III (66.7%) than in patients with EGJ type I (26.2%) and EGJ type II (30.3%; p < 0.001). Sliding hiatal hernia was more frequent in patients with EGJ type II (33.3%) than in patients with EGJ type III (16.7%) and EGJ type I (7.1%; p = 0.017). The mean esophagus–fundus angle of patients was 85 ± 31° at rest and increased to 101 ± 36° during Valsalva maneuver.

Conclusion

Real-time MRI is a non-invasive imaging method for assessment of the esophagogastric junction. Real-time MRI can visualize dynamic changes of the EGJ during swallowing events.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11604-021-01210-9.

Endoscopic Prediction for Acid Reflux in Patients without Hiatus Hernia

Background/Aims

A diagnosis of gastroesophageal reflux disease is challenging in patients who have reflux symptoms but do not respond to proton pump inhibitors nor have reflux esophagitis and hiatal hernia (HH) on endoscopy. This study examined the predictive role of the endoscopic findings, including the flap valve grade for pathologic acid exposure (PAE) to establish an endoscopic prediction model in patients with neither reflux esophagitis nor HH.

Methods

Five hundred seventy-eight patients who underwent upper endoscopy and 24 hours pH monitoring for reflux esophageal symptoms without evidence of reflux esophagitis and HH were analyzed. The gastroesophageal flap valve (GEFV), esophageal metaplasia, and chronic atrophic gastritis were assessed. The association between the endoscopic parameters and PAE was evaluated.

Results

Four hundred ninety-four patients were enrolled. The most common complaint was chest discomfort (42.3%) followed by globus (31.8%), dysphagia (7.9%), and heartburn (7.7%). PAE was present in 43 patients (8.7%). Multivariable analysis revealed PAE to be associated with the GEFV grade (p<0.001) and inversely associated with the chronic atrophic gastritis grade (p=0.005). Using these features, a predictive model was established and showed an area under the receiver operating characteristic curve of 0.705 (95% CI 0.619-0.790). The cutoff value of 12.0 had a sensitivity and specificity of 44.0% and 84.0%, respectively.

Conclusions

A loosened GEFV is associated with a risk of PAE in patients with neither reflux esophagitis nor HH, while atrophic gastritis is preventive. On the other hand, the endoscopic predictive model revealed a low sensitivity for detecting PAE. Thus, reflux testing needs to be performed further when gastroesophageal reflux disease is suspected, even without endoscopic evidence.

Integrative Effects and Vagal Mechanisms of Transcutaneous Electrical Acustimulation on Gastroesophageal Motility in Patients With Gastroesophageal Reflux Disease

INTRODUCTION

Impaired esophageal and gastric motilities are known to contribute to symptoms of gastroesophageal reflux disease (GERD). However, there is a lack of GERD therapy, targeting both gastric and esophageal functions. This study was designed to investigate the effects of transcutaneous electrical acustimulation (TEA) on symptoms of GERD and gastroesophageal functions and possible mechanisms in patients with GERD.

METHODS

Thirty patients with GERD with ineffective esophageal motility were equally divided and randomized into a 4-week sham-TEA or 4-week TEA treatment. The GERD questionnaire (GerdQ), GERD health-related quality-of-life questionnaire, high-resolution esophageal manometry, a nutrient drink test, the electrogastrogram, and ECG were performed to assess the severity of reflux symptoms, low esophageal sphincter (LES) pressure, distal contractile integral (DCI), gastric accommodation, gastric slow waves (GSW), and autonomic functions, respectively.

RESULTS

Compared with sham-TEA, the 4-week TEA treatment significantly decreased the GerdQ score (P = 0.011) and GERD health-related quality of life (P = 0.028) and improved nutrient drink-induced fullness (P < 0.001) and belching (P < 0.001) in patients with GERD. Although only acute TEA significantly enhanced LES pressure (P < 0.05), both acute and chronic TEA remarkedly increased DCI (P < 0.05) and reduced the incidence of ineffective esophageal contractions during wet swallows (P = 0.02). In addition, chronic TEA significantly increased gastric accommodation and the percentage of postprandial normal GSW compared with sham-TEA and baseline. Concurrently, TEA-enhanced vagal activity (P = 0.02) and the vagal activity positively correlated with LES pressure (r = 0.528; P = 0.003) and DCI (r = 0.522; P = 0.003).

DISCUSSION

The TEA treatment performed in this study improves reflux-related symptoms, increases DCI, reduces the incidence of ineffective esophageal contractions during wet swallows, and improves gastric accommodation and slow waves. The improvement in GERD symptoms might be attributed to the integrative effects of TEA on these gastroesophageal functions mediated via the vagal mechanism.

The Causes of Gastroesophageal Reflux after Laparoscopic Sleeve Gastrectomy: Quantitative Assessment of the Structure and Function of the Esophagogastric Junction by Magnetic Resonance Imaging and High-Resolution Manometry

BACKGROUND

The incidence of de novo gastroesophageal reflux disease (GERD) after LSG is substantial. However, an objective correlation with the structural gastric and EGJ changes has not been demonstrated yet. We aimed to prospectively evaluate the effects of laparoscopic sleeve gastrectomy (LSG) on the structure and function of the esophagogastric junction (EGJ) and stomach.

METHODS

Investigations were performed before and after > 50% reduction in excess body weight (6-12 months after LSG). Subjects with GERD at baseline were excluded. Magnetic Resonance Imaging (MRI), high-resolution manometry (HRM), and ambulatory pH-impedance measurements were used to assess the structure and function of the EGJ and stomach before and after LSG.

RESULTS

From 35 patients screened, 23 (66%) completed the study (age 36 ± 10 years, BMI 42 ± 5 kg/m²). Mean excess weight loss was 59 ± 18% after 7.1 ± 1.7-month follow-up. Esophageal acid exposure (2.4 (1.5-3.2) to 5.1 (2.8-7.3); p = 0.040 (normal < 4.0%)) and reflux events increased after surgery (57 ± 24 to 84 ± 38; p = 0.006 (normal < 80/day)). Esophageal motility was not altered by surgery; however, intrabdominal EGJ length and pressure were reduced (both p < 0.001); whereas the esophagogastric insertion angle (35° ± 11° to 51° ± 16°; p = 0.0004 (normal < 60°)) and esophageal opening diameter (16.9 ± 2.8 mm to 18.0 ± 3.7 mm; p = 0.029) were increased. The increase in reflux events correlated with changes in EGJ insertion angle (p = 0.010). Patients with > 80% reduction in gastric capacity (TGV) had the highest prevalence of symptomatic GERD.

CONCLUSION

LSG has multiple effects on the EGJ and stomach that facilitate reflux. In particular, EGJ disruption as indicated by increased (more obtuse) esophagogastric insertion angle and small gastric capacity were associated with the risk of GERD after LSG. clinicaltrials.gov: NCT01980420.

Evaluation of the Esophagogastric Junction on High Resolution Manometry

The esophagogastric junction (EGJ) is a complex barrier between the thoracic and abdominal luminal gut compartments, comprised primarily of the lower esophageal sphincter (LES) and crural diaphragm. Although closed at rest, the EGJ relaxes to allow antegrade bolus transit and retrograde venting of air. Abnormal relaxation is the hallmark of achalasia spectrum disorders, while increased frequency of transient lower esophageal sphincter relaxations and/or EGJ disruption are seen in gastroesophageal reflux disease. High resolution manometry (HRM) is the modern day gold standard for assessment of EGJ morphology and function, with better performance characteristics compared with endoscopy and barium esophagography. Conventional LES metrics defining EGJ function include resting LES pressure as well as postswallow residual pressures. Newer HRM-based metrics include EGJ contractile integral, which measures static barrier function at rest, and EGJ morphology, which characterizes the relationship between LES and crural diaphragm. Provocative maneuvers assess dynamic EGJ function during physiological or pharmacologic stress. The most useful of these maneuvers, the rapid drink challenge, assesses for latent obstruction, while multiple rapid swallows evaluate adequacy of deglutitive inhibition. Amyl nitrate and cholecystokinin administration can segregate motor from structural obstruction. Newer provocative tests (straight leg raise maneuver, abdominal compression) and novel diagnostic tools (functional lumen imaging probe) complement HRM evaluation of the EGJ. Although current HRM metrics and maneuvers show promise in identifying clinically relevant EGJ abnormalities, future investigations evaluating management outcomes will improve segregation of normal from abnormal EGJ morphology and function.

Three-Dimensional Pressure Profile of the Lower Esophageal Sphincter and Crural Diaphragm in Patients with Achalasia Esophagus

BACKGROUND & AIMS

Smooth muscles of the lower esophageal sphincter (LES) and skeletal muscle of the crural diaphragm (esophagus hiatus) provide the sphincter mechanisms at the esophagogastric junction (EGJ). We investigated differences in the 3-dimensional (3D) pressure profile of the LES and hiatal contraction between healthy subjects and patients with achalasia esophagus.

METHODS

We performed a prospective study of 10 healthy subjects (controls; 7 male; mean age, 60 ± 15 years; mean body mass index, 25 ± 2) and 12 patients with a diagnosis of achalasia (7 male; mean age, 63 ± 13 years; mean body mass index, 26 ± 1), enrolled at a gastroenterology clinic. Participants underwent 3D high-resolution manometry (3DHRM) with a catheter equipped with 96 transducers (for the EGJ pressure recording). A 0.5-mm metal ball was taped close to the transducer number 1 of the 3DHRM catheter. EGJ pressure was recorded at end-expiration (LES pressure) and at the peak of forced inspiration (hiatal contraction). Computed tomography (CT) scans were performed to localize the circumferential location of the metal ball on the catheter. Esophagus, LES, stomach, right and left crus of the diaphragm, and spine were segmented in each CT scan slice images to construct the 3D morphology of the region.

RESULTS

The metal ball was located at the 7 o'clock position in all controls. The circumferential orientation of metal ball was displaced 45 to 90 degrees in patients with achalasia compared with controls. The 3D-pressure profile of the EGJ at end-expiration and forced inspiration revealed marked differences between the groups. The LES turns to the left as it entered from the chest into the abdomen, forming an angle between the spine and LES. The spine-LES angle was smaller in patients with achalasia (104°) compared with controls (124°). Five of the 10 subjects with achalasia had physical breaks in the left crus of the diaphragm CONCLUSIONS: Besides LES, the 3D pressure profile of the EGJ can indicate anatomic and functional abnormalities of the crural diaphragm muscle in patients with achalasia esophagus. Further studies are needed to define the nature of hiatal and crural diaphragm dysfunction in patients with achalasia of the esophagus.

Tissue engineering of the gastroesophageal junction

The gastroesophageal junction has been of clinical interest for some time due to its important role in preventing reflux of caustic stomach contents upward into the esophagus. Failure of this role has been identified as a key driver in gastroesophageal reflux disease, cancer of the lower esophagus, and aspiration-induced lung complications. Due to the large population burden and significant morbidity and mortality related to reflux barrier dysfunction, there is a pressing need to develop tissue engineering solutions which can replace diseased junctions. While good progress has been made in engineering the bodies of the esophagus and stomach, little has been done for the junction between the two. In this review, we discuss pertinent topics which should be considered as tissue engineers begin to address this anatomical region. The embryological development and adult anatomy and histology are discussed to provide context about the native structures which must be replicated. The roles of smooth muscle structures in the esophagus and stomach, as well as the contribution of the diaphragm to normal anti-reflux function are then examined. Finally, engineering considerations including mechanics and current progress in the field of tissue engineering are presented.

Mechanism and Pathophysiology of Gastroesophageal Reflux Disease

Gastroesophageal reflux (GER) describes a process in which gastric contents travel retrograde into the esophagus. GER can be either a physiologic phenomenon that occurs in asymptomatic individuals or can potentially cause symptoms. When the latter occurs, this represents GER disease (GERD). The process by which GER transforms into GERD begins at the esophagogastric junction. Impaired clearance of the refluxate also contributes to GERD. Reflux causes degradation of esophageal mucosal defense. The refluxate triggers sensory afferents leading to symptom generation.

Prospective serial diagnostic study: the effects of position and provocative tests on the diagnosis of oesophageal motility disorders by high-resolution manometry

BACKGROUND

Standard high-resolution manometry (HRM) protocols are based on 10 single water swallows acquired in the supine position.

AIMS

To assess the impact of position, rapid drink challenge and solid test meal on the diagnosis of oesophageal motility disorders.

METHODS

Seventy-two healthy volunteers (20-76 years) and 366 consecutive patients (18-90 years) completed HRM with 10 single water swallows in the supine and upright positions. Rapid drink challenge was performed twice, before and after the solid test meal. Diagnosis based on single water swallows in the supine position (Chicago Classification v3.0) was compared with results in the upright position and with provocative tests.

RESULTS

Overall, diagnostic agreement in the supine and upright positions was present in 296/438 (67.6%) subjects. This increased to 90.0% when ineffective oesophageal motility was considered with normal motility. Integrated relaxation pressure was 4 mm Hg higher in the supine position. There was a higher prevalence of inconsistent, likely false positive, diagnoses of outlet obstruction in the supine compared to the upright position (16/20 vs 1/4 patients, P = 0.0007). Similarly, the difference in concordance for the diagnosis of oesophago-gastric junction obstruction or achalasia between single water swallows in the supine and upright positions with solid test meal was significant (12/29 (41.4%) vs 12/14 (85.7%), P = 0.0087).

CONCLUSION

Diagnostic agreement for oesophageal motility disorders based on single water swallows in the upright and supine positions was moderate, with frequent discordant findings for ineffective motility and outlet obstruction. HRM studies can be performed in either position, using appropriate reference values. Rapid drink challenge or solid test meal can resolve diagnostic discrepancies.

Real-time MRI for dynamic assessment of gastroesophageal reflux disease: Comparison to pH-metry and impedance

PURPOSE

To evaluate the diagnostic potential of real-time MRI for dynamic assessment of gastroesophageal reflux in patients with GERD (gastroesophageal reflux disease)-like symptoms compared to pH-metry and impedance.

METHODS

Patients who underwent real-time MRI and pH-metry between 2015-2018 were included in this retrospective study. Real-time MRI at 3 T was achieved by undersampled radial FLASH acquisitions with iterative image reconstruction by NLINV. Real-time MRI visualized transit of pineapple juice through the gastroesophageal junction and during Valsalva maneuver. MRI results were compared to 24 h pH-metry to assess acidic reflux (following Lyon Consensus guidelines) and to impedance to assess non-acidic reflux. A standard 2 × 2 table was chosen to calculate diagnostic performance.

RESULTS

91/93 eligible patients fulfilled inclusion criteria (male n = 49; female n = 42; median age 55 y). All MRI studies were successfully completed without adverse events at a mean examination time of 15 min. On real-time MRI, reflux was evident in 60 patients (66 %). pH-metry revealed reflux in 41 patients (45 %), and impedance in 54 patients (59 %). Compared to pH-metry and impedance, real-time MRI sensitivity was 0.78 (95 % CI: 0.66-0.87), specificity 0.67 (95 % CI: 0.45-0.84) and PPV 0.87 (95 % CI: 0.75-0.94).

CONCLUSION

Real-time MRI is an imaging method for assessment of gastroesophageal reflux in patients with GERD-like symptoms. Considering its high positive predictive value, real-time MRI can accurately identify patients in which further invasive testing with pH-metry and impedance might be considered.

Contribution of magnetic resonance imaging to the management of esophageal diseases: A systematic review

PURPOSE

Currently available imaging modalities used to investigate the esophagus are irradiating or limited to the analysis of the esophageal lumen. Magnetic resonance imaging (MRI) is a non-invasive and non-radiating imaging technique that provides high degrees of soft tissue contrast. Newly developed fast MRI sequences allow for both morphological and functional assessment of the esophageal body and esophagogastric junction. The purpose of this systematic review was to identify the contribution of MRI to the diagnosis and management of esophageal diseases, such as gastroesophageal reflux, esophageal motility disorders, esophageal neoplasms, and portal hypertension.

METHODS

We performed a systematic search of the Medline (via Ovid), EMBASE (via Ovid), PubMed and Cochrane Library databases from inception to December 2018 inclusively, using the MESH major terms "magnetic resonance imaging" AND "esophagus".

RESULTS

The initial search retrieved 310 references, of which 56 were found to be relevant for the study. References were analysed and classified in different subheadings: MRI protocols for the esophagus, gastroesophageal reflux disease, achalasia and other esophageal motility disorders, esophageal cancer, portal hypertension and other esophageal conditions.

CONCLUSION

MR Esophagography might become a non-invasive, non-irradiating technique of choice following diagnostic esophagogastroduodenoscopy for the assessment of esophageal diseases.

Endoscopic management of refractory gastroesophageal reflux disease

OBJECTIVE

Despite the therapeutic and surgical interventions for the management of gastroesophageal reflux disease (GERD), yet the high cost and the post-operative complications had led to a significant socioeconomic burden. The aim was to evaluate the safety and efficacy of endoscopic band ligation (EBL) in the management of refractory GERD.

METHODS

A total of 150 patients with refractory GERD were assigned to an EBL group (banding was done at four quadrants just at the gastroesophageal junction (GEJ) (n = 75) or to a control group (optimized dose of PPI, n = 75). Follow-up for both groups by upper GI endoscopy to evaluate the site of the Z line from the incisors, the width of the GEJ and the coaptation of GEJ around the endoscope on retroflection. PH monitoring was performed every 3 months with GERD- QoL assessment monthly for 1 year.

RESULTS

In EBL group; 58 patients (77.3%) needed 1 session, 17 patients (22.7%) needed 2 sessions. 4 rubber bands were utilized in 44 patients (58.7%), 3 rubber bands in 31 patients (41.3%). Follow-up for 1 year revealed a highly significant improvement of the GERD- QoL score, the site of Z line with significant reduction of reflux episodes and symptom index when compared to the medical treatment group. In EBL group; there were no major adverse events including bleeding, post band ulcers, stenosis at one year follow up.

CONCLUSION

The current study provides a novel endoscopic intervention to treat refractory GERD, which is safe, cost-effective, with no major adverse effects at one year follow up.

Acid Secretion and Its Relationship to Esophageal Reflux Symptom in Patients with Subtotal Gastrectomy

BACKGROUND

Esophageal reflux symptom has been reported as common in patients with subtotal gastrectomy. Management of postoperative esophageal reflux symptom is not satisfactory. The aim of this study is to investigate prevalence of esophageal reflux symptom after subtotal gastrectomy and assess factors affecting esophageal reflux symptom in subtotal gastrectomy patients.

METHODS

We prospectively enrolled 100 consecutive patients with subtotal gastrectomy who were regularly followed up by endoscopic examination. Acid secretory capacity was assessed by measuring messenger RNA (mRNA) expression of H⁺/K⁺-adenosine triphosphatase (ATPase) via real-time polymerase chain reaction (PCR) in biopsy specimens.

RESULTS

In total, 47 % of patients had typical esophageal reflux symptom, where heartburn or regurgitation was experienced at least weekly. Age, sex, body mass index, and type of reconstruction did not differ between esophageal reflux and non-esophageal-reflux groups. The esophageal reflux group had longer duration from time of operation until study (median 5.0 versus 3.6 years; P = 0.017). Hill grade for gastroesophageal (GE) flap valve was higher in the esophageal reflux group than in the non-esophageal-reflux group (P = 0.027). H⁺/K⁺-ATPase mRNA expression was higher in the esophageal reflux group than in the non-esophageal-reflux group [3967.6 (± 7583.7) versus 896.2 (± 1456.0); P = 0.006]. Multivariate analysis revealed that postoperative duration, H⁺/K⁺-ATPase mRNA expression level, and GE flap valve disruption were significantly associated with esophageal reflux symptom development.

CONCLUSIONS

Esophageal reflux symptom is common in patients after subtotal gastrectomy, possibly because of anti-reflux-barrier impairment and preservation of acid secretory capacity following surgery. Optimal acid suppression may be helpful in managing postoperative esophageal reflux symptom.

Analysis of computed tomographic findings according to gastroesophageal flap valve grade

BACKGROUND/AIMS

The gastroesophageal junction is an important barrier against gastroesophageal ref lux. Endoscopic grading of gastroesophageal f lap valve is simple, reproducible, and may predict reflux activity. We investigated the correlation between gastroesophageal flap valve grade and the gastroesophageal junction's structural properties using abdominal computed tomography.

METHODS

A total of 138 patients with early gastric cancer who underwent both pre-treatment esophagogastroduodenoscopy and water-distended stomach two-phase computed tomography were enrolled. Endoscopic gastroesophageal f lap valve grade and abdominal computed tomography findings were analyzed to assess anatomical factors including the gastroesophageal junction and related organs.

RESULTS

The angle of His increased significantly with gastroesophageal flap valve grade (grade I, 65.2˚ ± 19.6˚; grade II, 66.6˚ ± 19.8˚; grade III, 76.7˚ ± 11.9˚; grade IV, 120.0˚ ± 30.3˚; p < 0.001), as did the size of the diaphragmatic hiatus (grade I, 213.0 ± 53.8 mm² ; grade II, 232.6 ± 71.0 mm² ; grade III, 292.3 ± 99.2 mm² ; grade IV, 584.4 ± 268.3; p < 0.001). The length of the abdominal esophagus decreased as gastroesophageal flap valve grade increased (grade I, 34.6 ± 5.8 mm; grade II, 32.0 ± 6.5 mm; grade III, 24.6 ± 7.8 mm; grade IV, -22.6 ± 38.2 mm; p < 0.001). There was no significant relationship between gastroesophageal flap valve grade and visceral and subcutaneous fat areas (p = 0.877 and p = 0.508, respectively).

CONCLUSIONS

Endoscopic grading of the gastroesophageal flap valve is well correlated with anatomical changes around the gastroesophageal junction on abdominal computed tomography, and it can provide useful information about the anti-reflux barrier.

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

OBJECTIVE

To evaluate the manometric changes, function, and impact of magnetic sphincter augmentation (MSA) on the lower esophageal sphincter (LES).

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Prolonged measurement improves the assessment of the barrier function of the esophago-gastric junction by high-resolution manometry

BACKGROUND

Etiology of gastro-esophageal reflux disease (GERD) is multifactorial, but incompetence of the esophago-gastric junction (EGJ) appears to be of crucial importance. Established manometric parameters for assessment of EGJ barrier function are sub-optimal, potentially because they reflect only a very brief (up to 30 seconds), not necessarily representative period. This prospective, case-control study tested the performance of novel, high-resolution manometry (HRM) parameters of EGJ function in the assessment of GERD.

METHODS

Patients with reflux symptoms and healthy controls (HC) underwent standard HRM and 24-hour pH±impedance measurements. EGJ morphology, lower esophageal sphincter pressure integral (LES-PI), EGJ contractile integral (EGJ-CI) were compared with total-EGJ-CI, a novel parameter summarizing EGJ barrier function during the entire HRM protocol. Esophageal acid exposure ≥4.2%/24 h (A-Reflux-pos) or ≥73 reflux episodes in 24 hours (V-Reflux-pos) were considered pathological.

KEY RESULTS

Sixty five HC and 452 patients completed HRM, 380 (84%) patients underwent ambulatory reflux-monitoring. LES-PI, EGJ-CI and total-EGJ-CI correlated with EGJ morphology subtypes (all P<.00001). Only total-EGJ-CI was consistently lower in A-Reflux-pos and V-Reflux-pos subjects compared with HC and patients without GERD. Total-EGJ-CI was also the single best parameter for prediction of pathological reflux (optimal cut-off 47 mmHg cm, AUC 0.746, P<.0001). This cut-off value, approximately 1 SD below the mean normal value, showed modest sensitivity 54% and positive predictive value 46%, but good specificity 85% and negative predictive value 89% for GERD diagnosis.

CONCLUSION & INFERENCES

Total EGJ-CI, a new metric that summarizes EGJ contractility over time, allows an improved assessment of EGJ barrier function. Pathological reflux is unlikely if this metric is within the upper two-thirds of the normal range.

Gastrointestinal failure in the ICU

PURPOSE OF REVIEW

The current review summarizes different aspects of assessment of gastrointestinal function and provides a practical approach to management of adult patients with gastrointestinal dysfunction in the ICU.

RECENT FINDINGS

Different ways to define gastrointestinal failure have been used in the past. Recently, the term 'acute gastrointestinal injury (AGI)' has been proposed to specifically describe gastrointestinal dysfunction as a part of multiple organ dysfunction syndrome. Possible pathophysiological mechanisms and different aspects in assessment of gastrointestinal function in adult ICU patients are presented. Currently, there is no single marker that could reliably describe gastrointestinal dysfunction. Therefore, monitoring and management is still based on complex assessment of different gastrointestinal symptoms and feeding intolerance, even though this approach includes a large amount of subjectivity. The possible role of biomarkers (citrulline, enterohormones, etc.) and additional parameters like intra-abdominal pressure remains to be clarified.

SUMMARY

Defining gastrointestinal failure remains challenging but broad consensus needs to be reached and disseminated soon to allow conduct of interventional studies. A systematic approach to management of gastrointestinal problems is recommended.

What is the role of radiological testing of lower esophageal sphincter function?

Radiological fluoroscopic evaluation remains the primary imaging modality of choice to evaluate patients with swallowing disorders, despite the increasing availability and technical advantages of nonradiological techniques and the current radiological focus on cross-sectional imaging studies, such as computed tomography and magnetic resonance imaging. The radiological swallowing evaluation should be tailored to assess the entire upper gastrointestinal tract, including the lower esophageal sphincter. Fluoroscopy enables the simultaneous assessment of esophageal motility disorders, as well as structural pathologies, including strictures, webs, rings, diverticula, and tumors. Mono- and double-contrast esophagrams and solid bolus tests together allow assessment of lower esophageal sphincter function and complement other methods, such as endoscopy, manometry, or impedance planimetry. Here we review the role of radiological studies for correct assessment of structural and functional pathologies at the level of the lower esophageal sphincter.

Magnetic resonance imaging biomarkers of gastrointestinal motor function and fluid distribution

Magnetic resonance imaging (MRI) is a well established technique that has revolutionized diagnostic radiology. Until recently, the impact that MRI has had in the assessment of gastrointestinal motor function and bowel fluid distribution in health and in disease has been more limited, despite the novel insights that MRI can provide along the entire gastrointestinal tract. MRI biomarkers include intestinal motility indices, small bowel water content and whole gut transit time. The present review discusses new developments and applications of MRI in the upper gastrointestinal tract, the small bowel and the colon reported in the literature in the last 5 years.

Laparoscopic sleeve gastrectomy and gastroesophageal reflux

Bariatric surgery is the only effective procedure that provides long-term sustained weight loss. Sleeve gastrectomy (SG) has emerged over the last few years to be an ideal bariatric procedure because it has several advantages compared to more complex bariatric procedures, including avoiding an intestinal bypass. However, several published follow-up studies report an increased rate of gastroesophageal reflux (GERD) after a SG. GERD is described as either de novo or as being caused by aggravation of preexisting symptoms. However, the literature on this topic is ambivalent despite the potentially increased rate of GERDs that may occur after this common bariatric procedure. This article reviews the mechanisms responsible for GERD in obese subjects as well as the results after a SG with respect to GERD. Future directions for clinical research are discussed along with the current surgical options for morbidly obese patients with GERD and undergoing bariatric surgery.

Volume, distribution and acidity of gastric secretion on and off proton pump inhibitor treatment: a randomized double-blind controlled study in patients with gastro-esophageal reflux disease (GERD) and healthy subjects

Background

Postprandial accumulation of gastric secretions in the proximal stomach above the meal adjacent to the esophagogastric junction (EGJ), referred to as the ‘acid pocket’, has been proposed as a pathophysiological factor in gastro-esophageal reflux disease (GERD) and as a target for GERD treatment. This study assessed the effect of proton pump inhibitor (PPI) therapy on the volume, distribution and acidity of gastric secretions in GERD and healthy subjects (HS).

Methods

A randomized, double blind, cross-over study in 12 HS and 12 GERD patients pre-treated with 40 mg pantoprazole (PPI) or placebo b.i.d. was performed. Postprandial secretion volume (SV), formation of a secretion layer and contact between the layer and the EGJ were quantified by Magnetic Resonance Imaging (MRI). Multi-channel pH-monitoring assessed intragastric pH.

Results

A distinct layer of undiluted acid secretion was present on top of gastric contents in almost all participants on and off high-dose acid suppression. PPI reduced SV (193 ml to 100 ml, in HS, 227 ml to 94 ml in GERD; p < 0.01) and thickness of the acid layer (26 mm to 7 mm, 36 mm to 9 mm respectively, p < 0.01). No differences in secretion volume or layer thickness were observed between groups; however, off treatment, contact time between the secretion layer and EGJ was 2.6 times longer in GERD compared to HS (p = 0.012). This was not the case on PPI.

Conclusions

MRI can visualize and quantify the volume and distribution dynamics of gastric secretions that form a layer in the proximal stomach after ingestion of a liquid meal. The secretion volume and the secretion layer on top of gastric contents is similar in GERD patients and HS; however contact between the layer of undiluted secretion and the EGJ is prolonged in patients. High dose PPI reduced secretion volume by about 50 % and reduced contact time between secretion and EGJ towards normal levels.

Trial registration

NCT01212614.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0343-x) contains supplementary material, which is available to authorized users.

Pathophysiology of gastroesophageal reflux disease: new understanding in a new era

BACKGROUND

The prevalence of gastroesophageal reflux disease (GERD) has increased in the last decades and it is now one of the most common chronic diseases. Throughout time our insight in the pathophysiology of GERD has been characterized by remarkable back and forth swings, often prompted by new investigational techniques. Even today, the pathophysiology of GERD is not fully understood but it is now recognized to be a multifactorial disease. Among the factors that have been shown to be involved in the provocation or increase of reflux, are sliding hiatus hernia, low lower esophageal sphincter pressure, transient lower esophageal sphincter relaxation, the acid pocket, obesity, increased distensibility of the esophagogastric junction, prolonged esophageal clearance, and delayed gastric emptying. Moreover, multiple mechanisms influence the perception of GERD symptoms, such as the acidity of the refluxate, its proximal extent, the presence of gas in the refluxate, duodenogastroesophageal reflux, longitudinal muscle contraction, mucosal integrity, and peripheral and central sensitization. Understanding the pathophysiology of GERD is important for future targets for therapy as proton pump inhibitor-refractory GERD symptoms remain a common problem.

PURPOSE

In this review we provide an overview of the mechanisms leading to reflux and the factors influencing perception, in the light of historical developments. It is clear that further research remains necessary despite the recent advances in the understanding of the pathophysiology of GERD.

Predictive value of routine esophageal high-resolution manometry for gastro-esophageal reflux disease

BACKGROUND

Using conventional manometry, gastro-esophageal reflux disease (GERD) was associated with a reduced lower esophageal sphincter (LES) pressure and impaired peristalsis. However, with a large overlap between GERD patients and controls, these findings are of limited clinical relevance. It is uncertain whether the more detailed information of high-resolution manometry (HRM) can discriminate GERD patients. Therefore, we aimed to determine to which extent HRM findings can predict GERD.

METHODS

HRM measurements in 69 patients with GERD and 40 healthy subjects were compared and the predictive value of HRM for the diagnosis of GERD was explored.

KEY RESULTS

GERD patients had a significantly lower contraction amplitude (55 vs 64 mmHg; p = 0.045) and basal LES pressure (10 vs 13.2 mmHg; p = 0.034) than healthy controls. GERD patients more often had a hiatal hernia than healthy subjects (30% vs 7%; p = 0.005). Patients with reflux esophagitis had a lower DCI than patients without reflux esophagitis (558 vs 782 mmHg cm s; p = 0.045). No significant difference was seen in contractile front velocity, distal latency, number of peristaltic breaks, residual LES pressure and LES length. On multivariate logistic regression analysis, both esophagogastric junction type I (OR 4.971; 95% CI 1.33-18.59; p = 0.017) and mean wave amplitude (OR 0.95; 95% CI 0.90-0.98; p = 0.013) were found to be independent predictors of GERD. However, the sensitivity and specificity of these findings were low.

CONCLUSIONS & INFERENCES

Hiatal hernia, low contraction amplitude and LES pressure are associated with GERD, but do not predict the disease with sufficient accuracy. Routine esophageal HRM can therefore not be used to distinguish GERD patients from healthy subjects.

Validation of a rapid, semiautomatic image analysis tool for measurement of gastric accommodation and emptying by magnetic resonance imaging

Magnetic resonance imaging (MRI) has advantages for the assessment of gastrointestinal structures and functions; however, processing MRI data is time consuming and this has limited uptake to a few specialist centers. This study introduces a semiautomatic image processing system for rapid analysis of gastrointestinal MRI. For assessment of simpler regions of interest (ROI) such as the stomach, the system generates virtual images along arbitrary planes that intersect the ROI edges in the original images. This generates seed points that are joined automatically to form contours on each adjacent two-dimensional image and reconstructed in three dimensions (3D). An alternative thresholding approach is available for rapid assessment of complex structures like the small intestine. For assessment of dynamic gastrointestinal function, such as gastric accommodation and emptying, the initial 3D reconstruction is used as reference to process adjacent image stacks automatically. This generates four-dimensional (4D) reconstructions of dynamic volume change over time. Compared with manual processing, this semiautomatic system reduced the user input required to analyze a MRI gastric emptying study (estimated 100 vs. 10,000 mouse clicks). This analysis was not subject to variation in volume measurements seen between three human observers. In conclusion, the image processing platform presented processed large volumes of MRI data, such as that produced by gastric accommodation and emptying studies, with minimal user input. 3D and 4D reconstructions of the stomach and, potentially, other gastrointestinal organs are produced faster and more accurately than manual methods. This system will facilitate the application of MRI in gastrointestinal research and clinical practice.

Measurement of gastric meal and secretion volumes using magnetic resonance imaging

MRI can assess multiple gastric functions without ionizing radiation. However, time consuming image acquisition and analysis of gastric volume data, plus confounding of gastric emptying measurements by gastric secretions mixed with the test meal have limited its use to research centres. This study presents an MRI acquisition protocol and analysis algorithm suitable for the clinical measurement of gastric volume and secretion volume. Reproducibility of gastric volume measurements was assessed using data from 10 healthy volunteers following a liquid test meal with rapid MRI acquisition within one breath-hold and semi-automated analysis. Dilution of the ingested meal with gastric secretion was estimated using a respiratory-triggered T1 mapping protocol. Accuracy of the secretion volume measurements was assessed using data from 24 healthy volunteers following a mixed (liquid/solid) test meal with MRI meal volumes compared to data acquired using gamma scintigraphy (GS) on the same subjects studied on a separate study day. The mean ± SD coefficient of variance between 3 observers for both total gastric contents (including meal, secretions and air) and just the gastric contents (meal and secretion only) was 3  ±  2% at large gastric volumes (>200 ml). Mean ± SD secretion volumes post meal ingestion were 64  ±  51 ml and 110  ±  40 ml at 15 and 75 min, respectively. Comparison with GS meal volumes, showed that MRI meal only volume (after correction for secretion volume) were similar to GS, with a linear regression gradient ± std err of 1.06  ±  0.10 and intercept -11  ±  24 ml. In conclusion, (i) rapid volume acquisition and respiratory triggered T₁ mapping removed the requirement to image during prolonged breath-holds (ii) semi-automatic analysis greatly reduced the time required to derive measurements and (iii) correction for secretion volumes provided accurate assessment of gastric meal volumes and emptying. Together these features provide the scientific basis of a protocol which would be suitable in clinical practice.

Mechanisms of Barrett's oesophagus (clinical): LOS dysfunction, hiatal hernia, peristaltic defects

Barrett's oesophagus, with the potential to develop into oesophageal adenocarcinoma (OAC), is a major complication of gastrooesophageal reflux disease (GORD). However, about 50% of patients developing OAC had no known GORD beforehand. Hence, while GORD symptoms, oesophagitis, and Barrett's have a number of common determinants (oesophagogastric junction (OGJ) incompetence, impaired oesophageal clearance mechanisms, hiatus hernia) they also have some independent determinants. Further, although excess oesophageal acid exposure plays a major role in the genesis of long-segment Barrett's oesophagus there is minimal evidence supporting this for short-segment Barrett's. Hence, these may have unique pathophysiological features as well. Long-segment Barrett's seems to share most, if not all, of the risk factors for oesophagitis, particularly high-grade oesophagitis. However, it is uncertain if OGJ function and acid clearance are more severely impaired in patients with long-segment Barrett's compared to patients with high-grade oesophagitis. With respect to short-segment Barrett's, the acid pocket may play an important pathogenic role. Conceptually, extension of the acid pocket into the distal oesophagus, also known as intra-sphincteric reflux, provides a mechanism or acid exposure of the distal osophageal mucosa without the occurrence of discrete reflux events, which are more likely to prompt reflux symptoms and lead to the development of oesophagitis. Hence, intra-sphincteric reflux related to extension of the acid/no acid interface at the proximal margin of the acid pocket may be key in the development of short segment Barrett's. However, currently this is still somewhat speculative and further studies are required to confirm this.

Effects of baclofen on the functional anatomy of the oesophago-gastric junction and proximal stomach in healthy volunteers and patients with GERD assessed by magnetic resonance imaging and high-resolution manometry: a randomised controlled double-blind study

BACKGROUND

The mechanism of reflux protection may involve a 'flap valve' at the oesophago-gastric junction (OGJ).

AIM

To assess the effects of baclofen, a gamma-aminobutyric acid receptor type-B (GABA-B) agonist known to suppress reflux events, on the 'functional anatomy' of the OGJ and proximal stomach after a large test meal.

METHODS

Twelve healthy volunteers (HVs) and 12 patients with gastro-oesophageal reflux disease (GERD); with erosive oesophagitis or pathological oesophageal acid exposure completed a randomised, double-blind, cross-over study. On 2 test days participants received 40-mg baclofen or placebo before ingestion of a large test meal. OGJ structure and function were assessed by high-resolution manometry (HRM) and magnetic resonance imaging (MRI) using validated methods. Measurements of the oesophago-gastric angle were derived from three-dimensional models reconstructed from anatomic MRI images. Cine-MRI and HRM identified postprandial reflux events. Mixed model analysis and Wilcoxon rank signed tests assessed differences between participant groups and treatment conditions.

RESULTS

In both HVs and GERD patients, baclofen reduced the frequency of postprandial reflux events. The oesophago-gastric insertion angle in GERD patients was reduced (-4.1 ± 1.8, P = 0.025), but was unchanged in healthy controls. In both study groups, baclofen augmented lower oesophageal sphincter (LES) pressure (HVs: +7.3 ± 1.8 mmHg, P < 0.0001, GERD: +4.50 ± 1.49 mmHg, P < 0.003) and increased LES length (HVs: +0.48 ± 0.11 cm, P < 0.0003, GERD: +0.35 ± 0.06 cm, P < 0.0001).

CONCLUSIONS

Baclofen inhibits transient LES relaxations and augments LES pressure and length. Additionally, baclofen has effects on the 'functional anatomy' of the OGJ and proximal stomach in GERD patients, which may suppress reflux by means of a 'flap valve' mechanism.