Gastro-oesophageal reflux disease and obesity: pathogenesis and response to treatment

American society for metabolic and bariatric surgery: intra-operative care pathway for minimally invasive Roux-en-Y gastric bypass

BACKGROUND

Clinical care pathways help guide and provide structure to clinicians and providers to improve healthcare delivery and quality. The Quality Improvement and Patient Safety Committee (QIPS) of the American Society for Metabolic and Bariatric Surgery (ASMBS) has previously published care pathways for the performance of laparoscopic sleeve gastrectomy (LSG) and pre-operative care of patients undergoing Roux-en-Y gastric bypass (RYGB).

OBJECTIVE

This current RYGB care pathway was created to address intraoperative care, defined as care occurring on the day of surgery from the preoperative holding area, through the operating room, and into the postanesthesia care unit (PACU).

METHODS

PubMed queries were performed from January 2001 to December 2019 and reviewed according to Level of Evidence regarding specific key questions developed by the committee.

RESULTS

Evidence-based recommendations are made for care of patients undergoing RYGB including the pre-operative holding area, intra-operative management and performance of RYGB, and concurrent procedures.

CONCLUSIONS

This document may provide guidance based on recent evidence to bariatric surgeons and providers for the intra-operative care for minimally invasive RYGB.

Safety of limb lengthening after Roux-en-Y gastric bypass: an analysis of the MBSAQIP database

BACKGROUND

Roux-en-Y gastric bypass (RYGB) effectively treats severe obesity, but some patients may require revisional surgery like limb lengthening (LL) for postoperative weight gain.

OBJECTIVES

This study aims to compare 30-day serious complications and mortality rates between LL and primary RYGB, given limited safety data on LL.

METHODS

Patients who underwent LL and RYGB were identified from the 2020 and 2021 MBSAQIP databases, the only years in which LL data were available. Baseline characteristics and 30-day rates of serious complications and mortality were analyzed.

RESULTS

A total of 86,990 patients underwent RYGB and 455 underwent LL. Patients undergoing RYGB were younger (44.4 versus 49.8 yr, P < .001), had a higher body mass index (BMI) (45.5 versus 41.8 kg/m2, P < .001) and higher rates of comorbidities including diabetes (30.0 versus 13.6%, P < .001). RYGB and LL had similar operative duration (125.3 versus 123.2 min, P = .5). There were no statistical differences between cohorts for length of stay (LOS) (1.6 RYGB versus 1.6 LL d, P = .6). After LL, there were higher 30-day rates of reoperation (3.3 versus 1.9%, P = .03) and deep surgical site infections (1.3 versus .5%, P = .03) compared to RYGB. There were no differences in overall serious complications (5.1 LL versus 5.0% RYGB, P = 1.0) and mortality (.2 LL versus .1% RYGB, P = .5). Multivariable logistic regression adjustment found that previous venous thromboembolism was associated with serious complications after LL.

CONCLUSIONS

When compared to primary RYGB, LL has a favorable safety profile with similar 30-day rates of serious complications and mortality.

The new onset of GERD after sleeve gastrectomy: A systematic review

Background

The main adverse effect is gastroesophageal reflux disease (GERD), with concern on the development of Barrett's esophagus and esophageal adenocarcinoma in the long term. However, the relationship between SG and GERD is complex. The aim of this study is to systematically evaluate all published data existing in the literature to evaluate the effect of sleeve gastrectomy on GERD, esophagitis, BE in order to clarify the long-term clinical sequelae of this procedure.

Materials and methods

This systematic review was conducted in accordance with the guidelines for Preferred Reporting Items for Systematic Review. The work has been reported in line with the PRISMA criteria [19]. We evaluated the quality and risk of bias of this Systematic Review using AMSTAR 2 checklist [20]. Published studies that contained outcome data for primary sleeve gastrectomy associated with the primary and secondary outcomes listed below were included. The UIN for ClinicalTrial.gov Protocol Registration and Results System is: NCT05178446 for the Organization UFoggia.

Results

49 articles were eligible for inclusion that met the following criteria: publications dealing with patients undergoing laparoscopic SG, publications describing pre- and postoperative GERD symptoms and/or esophageal function tests, articles in English, human studies and text complete available.

Conclusions

We have controversial data on LSG and GERD in the literature as there is a multifactorial relationship between LSG and GERD. The most recent studies have shown satisfactory control of postoperative reflux in most patients and low rates of de novo GERD. These data are leading to wider acceptance of LSG as a bariatric procedure even in obese patients with GERD.

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The aim of this study is to evaluate the effect of sleeve gastrectomy on GERD.

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In the literature there are controversial results on the onset of GERD after LSG.

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Satisfactory control of postoperative reflux in most patients and low rates of de novo GERD.

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These data are leading to wider acceptance of LSG as a bariatric procedure even in obese patients with GERD.

Assessment and management of gastroesophageal reflux disease following bariatric surgery

Gastroesophageal reflux disease (GERD) is a common disease in patients with obesity. The incidence of de novo GERD and the effect of bariatric surgery on patients with pre-existing GERD remain controversial. Management of GERD following bariatric surgery is complicated and can range from medical therapy to non-invasive endoscopic options to invasive surgical options. To address these issues, we performed a systematic review of the literature on the incidence of GERD and the various modalities of managing GERD in patients following bariatric surgery. Given the increased number of laparoscopic sleeve gastrectomy (LSG) procedures being performed and the high incidence of GERD following LSG, bariatric surgeons should be familiar with the options available to manage GERD following LSG as well as other bariatric procedures.

Current status of gastroesophageal reflux disease after sleeve gastrectomy: Still a long way to go

Obesity is a public health concern that is becoming increasingly more serious around the world. Bariatric surgery has become more prevalent due to the obesity epidemic worldwide. Sleeve gastrectomy (SG) is one of the most popular procedures which is safe and efficient. Despite all its favorable features, however, there is an increasing evidence from the literature that the long-term incidence of gastroesophageal reflux disease (GERD) is likely to represent the Achilles' heel of this procedure. Management of severe reflux after SG usually requires revisional surgery. The relationship between SG and GERD needs to be better ascertained in order to prevent related complications, such as esophageal adenocarcinoma. This review attempts to elucidate the effect of SG on GERD and the postoperative management of reflux disease according to recent literature in the hope of drawing the attention of clinicians to postoperative gastroesophageal reflux and guiding the optimal management strategy associated with this "troublesome complication".

The Spectrum of Helicobacter-Mediated Diseases

Helicobacter pylori is the leading cause of peptic ulcer disease. The infection has been implicated in more than 75% of duodenal ulcer cases and 17% of gastric ulcer cases. H. pylori has been classified as a human carcinogen, since it is the main cause of distal gastric adenocarcinoma and B cell mucosa-associated lymphoid tissue lymphoma. Evidence also links H. pylori with extragastric conditions including iron deficiency anemia, idiopathic thrombocytopenic purpura, and vitamin B₁₂ deficiency. Studies indicate that H. pylori may be protective against other conditions of the gastrointestinal tract (e.g., reflux esophagitis and related pathologies) and elsewhere in the body (e.g., asthma). The infection is asymptomatic in the vast majority of cases; more serious outcomes occur in only 10-15% of infected individuals. Despite extensive research over the past 3 decades, there is no effective vaccine, and the circumstances leading to disease development remain unclear. In addition, there is now a growing prevalence of antimicrobial resistance in H. pylori. This review discusses these important issues.

Outcomes of laparoscopic sleeve gastrectomy by means of esophageal manometry and pH-metry, before and after surgery

INTRODUCTION

Gastroesophageal reflux is a major problem after sleeve gastrectomy. There is still insufficient understanding of how it occurs and whether it is due to the sphincter length, relaxation, or pressure differences.

AIM

This study evaluates the effect on the lower esophageal sphincter of the laparoscopic sleeve gastrectomy (LSG) technique applied in surgery in cases of morbid obesity using ambulatory 24-h pH monitoring (APM) and esophageal manometry (EM).

MATERIAL AND METHODS

A retrospective examination was carried out on the APM and EM tests performed preoperatively and postoperatively in cases of LSG. The parameters examined were the body mass index (BMI), amplitude pressure of the esophagus (AP), total length of the lower esophageal segment (LESL), resting pressure of the LES (LESP), residual pressure of the LES (LESR), relaxation time of the LES, intragastric pressure, and the DeMeester score.

RESULTS

A total of 62 cases with available data were evaluated. A statistically significant difference was determined between the preoperative values and the 3-month postoperative values of BMI, LESP, and relaxation time of the LES. A statistically significant increase was determined in the DeMeester score, and the increase in the total number of reflux episodes longer than 5 min was found to be the most responsible for this increase. No significant difference was determined in the other parameters.

CONCLUSIONS

The LSG was found to cause a reduction in LESP, and an increase in acid reflux causing an extended relaxation time of the LES. This was confirmed by the increase seen in the DeMeester score.

Adult obesity complications: challenges and clinical impact

The complications associated with adult obesity are overwhelming national healthcare systems. No country has yet implemented a successful population-level strategy to reverse the rising trends of obesity. This article presents epidemiological data on the complications of adult obesity and discusses some of the challenges associated with managing this disease at a population and individual level.

Reflux esophagitis, functional and non-functional

The pathogenesis of gastroesophageal reflux disease has been explained by acid-peptic model. However, related with the progress of the diagnostic modalities, another phenotypical group of patients were defined and called "functional disorders of the esophagus". These patients are important because diagnosis is particularly difficult, co-morbid disorders especially psychiatric diseases are common, proton pump inhibitor response is low, and surgical results are very poor. Simpler and translational science studies are required in functional groups in order to differentiate from acid-peptic disorders. New and more accurate diagnostic modalities as well as therapeutic approaches are strongly needed in this particularly new and exciting era, especially in the effect of neuromodulators. Current diagnostic modalities should also be evaluated and in fact, normal values should be established. New medications, especially acting at the level of esophageal epithelium and intercellular spaces, might shift the paradigm.

Gastroesophageal reflux-related physiologic changes after sleeve gastrectomy and Roux-en-Y gastric bypass: a prospective comparative study

BACKGROUND

The development of gastroesophageal reflux disease (GERD) after laparoscopic sleeve gastrectomy (LSG) is a major concern as it affects the quality of life of the patients and potentially exposes them to the complications of GERD. The reported incidence of GERD after LSG is up to 35%. Laparoscopic Roux-en-Y gastric bypass (LRYGB) is considered the procedure of choice for patients with morbid obesity with GERD but objective evidence based on physiologic studies for the same are limited.

OBJECTIVE

The objectives of the study were to determine the physiologic changes related to gastroesophageal reflux based on symptoms index, 24-hour pH study, impedance, and manometry after LSG and LRYGB.

SETTINGS

Tertiary care teaching hospital, India.

METHODS

This registered study (CTRI/2017/06/008834) is a prospective, nonrandomized, open-label clinical trial comparing the incidence of GERD after LSG and LRYGB. In this study, non-GERD patients were evaluated for GERD based on clinical questionnaires, 24-hour pH study, and impedance manometry preoperatively and 6 months postoperatively.

RESULTS

Thirty patients underwent LSG, and 16 patients underwent LRYGB. The mean DeMeester score increased from 10.9 ± 11.8 to 40.2 ± 38.6 (P = .006) after LSG. The incidence of GERD after LSG was 66.6%. The increase in DeMeester score from 9.5 ± 4.6 to 12.2 ± 17.2 after LRYGB was not significant (P = .7). There was a significant increase in the nonacid reflux both after LSG and LRYGB.

CONCLUSION

The incidence of GERD after LSG is high, making it a contraindication for LSG. LRYGB remains the preferred procedure for patients with GERD. However, more studies are needed to understand the physiologic changes in patients with preexisting GERD.

GASTROINTESTINAL MOTILITY DISORDERS IN OBESITY

The gastrointestinal (GI) motility, which is important for the digestion and absorption, may be altered in obesity. The aim of this review is to present the GI motility changes occurring in obesity, as well as their underlying mechanisms. We have conducted a systematic review of the published literature concerning GI motility and obesity and have described recent published data on the changes throughout the entire GI tract. Most recent discoveries include evidence supporting the increase of gastroesophageal reflux disease in obesity and inhibition of gastric motility. Intestinal transit of the distal small bowel generally slows down, ensuring enough time for digestion and absorption. Constipation is more frequent in obese patients than in those with a normal weight. The gut-brain axis plays an important role in the pathophysiology of GI motility disorders in obesity. This bidirectional communication is achieved by way of neurons, hormones, metabolites derived from intestinal microbiota and cytokines. The molecular mechanisms of GI motility changes in obesity are complex. Current data offer a starting point for further research needed to clarify the association of obesity with GI motility disorders.

Gastroesophageal Reflux Disease in Obese Patients

Gastroesophageal reflux disease (GERD) and obesity coexist in many patients in the Western population. The association is not coincidental, since GERD pathophysiology is, in part, linked to obesity. Visceral adipose tissue secretes hormones, which increase the risk of GERD. Obesity increases esophageal motor disorders and higher number of transient lower esophageal sphincter relaxations. Central obesity increases abdominal-thoracic pressure gradient and disrupts the gastroesophageal junction by inducing hiatal hernia formation. Obese patients benefit from weight loss by diet to decrease GERD symptoms; however, Roux-en-Y gastric bypass surgery is associated with a higher weight loss and a decrease in GERD symptoms, and is considered the best way to treat both diseases at the same time.

De novo gastroesophageal reflux disease after sleeve gastrectomy: role of preoperative silent reflux

BACKGROUND

Laparoscopic sleeve gastrectomy (LSG) has become the most frequently performed bariatric procedure to date. However, LSG is known to worsen pre-operative and result in de novo gastroesophageal reflux disease (GERD). Pre-operative evaluation reveals a high percentage of silent GERD of so far unknown influence on post-operative GERD.

METHODS

Prospective data of patients undergoing primary LSG between 01/2012 and 12/2015 were evaluated. Pre-operative GERD-specific evaluation consisted of validated questionnaires, upper endoscopy, 24 h-pH-manometry, and esophagograms. Patients were followed-up with questionnaires every 6 months, upper endoscopies after 1 year and 24 h-pH-metry after 2 years. Silent GERD was defined as esophagitis grade > B and/or abnormal esophageal acid exposure in absence of symptoms. LSG was performed over a 32F bougie, hiatal hernias > 1 cm were addressed with posterior hiatoplasty. Excluded were patients with hiatal hernias > 4 cm, patients with incorrect anatomy (stenosis, fundus too large) and conversion to RYGB for early leaks.

RESULTS

222 patients were included. Mean follow-up was 32 ± 16 months, mean preoperative body mass index 49.6 ± 7.2 kg/m². 116 patients (52%) presented with post-operative GERD-symptoms, of which 85 (73%) had de novo symptoms. Of those, 48 (of 85, 56%) had no preoperative GERD and 37 (of 85, 44%) silent GERD. 57 patients (26%) had neither pre- nor post-operative GERD, 7 (3%) had silent pre-operative and no postop GERD, and in 19 patients (9%) GERD was cured with LSG. 31 patients (14%) stayed symptomatic. Of 56 patients (25%) with pre-operative silent GERD, 37 (of 54, 66%) became symptomatic.

CONCLUSION

LSG leads to a considerable rate of post-operative GERD. De novo-GERD consist of around half of pre-operative silent GERD and completely de novo-GERD. Most patients with pre-operative silent GERD became symptomatic.

SLEEVE GASTRECTOMY AND FUNDOPLICATION AS A SINGLE PROCEDURE IN PATIENTS WITH OBESITY AND GASTROESOPHAGEAL REFLUX

BACKGROUND

Bariatric surgery in Chile has seen an exponential increase in recent years, especially in sleeve gastrectomy. Its use is currently discussed in patients suffering from gastroesophageal reflux disease. Different options have been considered for the management of these patients but up to now laparoscopic Roux-en-Y gastric bypass seems to be the best option. Sleeve gastrectomy plus concomitant fundoplication or hiatal hernia repair also has been suggested in patients having reflux or small hiatal hernia.

AIM

To present a cohort of obese patients with gatroesophageal reflux undergoing this procedure, which seeks to provide the benefits of both laparoscopic gastric sleeve (LSG) and antireflux surgery focused on the evaluation of presence of reflux and BMI after surgery, and to compare the result observed in this cohort with a previous group of obese patients without reflux submitted to sleeve gastrectomy alone.

METHODS

Retrospective case series in 15 patients who underwent this surgery between the years 2003 and 2012. Clinical records were analyzed and values ​​of 24 hr pH monitoring, esophageal manometry and clinical outcome were recorded. Results were compared to a previous series of patients who underwent LSG. No statistical analyses were made.

RESULTS

Group A consisted of 15 patients submitted to LSG plus fundoplication. 93% (n=14) were female. Mean age was 46.2 years. Mean preoperative body mass index (BMI) was 33.9. All patients had altered pH monitoring and manometry preoperatively. There was one minor complication corresponding to a seroma. There was no perioperative mortality. Group B consisted of 23 obese patients who underwent LSG. These patients developed de novo reflux, hypotensive LES and esophagitis after the surgery. Group A patients showed improvement in esophageal pH monitoring and manometry at three months. During long-term follow-up, six underwent revision surgery, four for weight regain, one regained weight associated with symptomatic reflux, and one underwent re-intervention for reflux.

CONCLUSIONS

Good results are observed in the short-term follow up in both reflux resolution and weight loss. Nevertheless, results at long term are discouraging, with 53.3% of the patients requiring revision surgery during follow-up.

The Changing Impact of Gastroesophageal Reflux Disease in Clinical Practice

Objectives:

The National Ambulatory Medical Care Survey (NAMCS) database was utilized to understand evolving national trends in diagnosis and management of reflux.

Methods:

The NAMCS database was queried for visits related to gastroesophageal reflux diagnosis and management. Analysis performed for time periods 1998-2001, 2002-2005, and 2006-2009 was weighted to provide national estimates of care. Results were compared to previously reported time periods from 1990 to 2001 to evaluate patterns in overall visits, age and ethnicity of patients, provider type, and prescriptions provided.

Results:

The number of ambulatory visits for reflux increased from 8 684 000 in 1998-2001 to 15 750 000 in 2006-2009. Visits increased across each time period for internal medicine, family, and gastroenterology physicians. Among otolaryngologists, absolute visits increased from 1998-2001 to 2002-2005 but decreased in 2006-2009; difference between these time periods did not reach statistical significance. From 1998-2001 to 2006-2009, reflux medication use increased 233%, with continuing trends toward increased proton pump inhibitor use.

Conclusions:

Reflux visits have increased across all demographic subgroups studied. Knowledge of these trends may inform further paradigm shifts in diagnosis and management of reflux.

Risk factors for erosive and non-erosive gastroesophageal reflux disease and Barrett's esophagus in Nothern Sardinia

OBJECTIVE

Gastroesophageal reflux disease (GERD) and esophageal adenocarcinoma have been increasing. We studied the relationship of conventional risk factors and Helicobacter pylori infection in patients with erosive and non-erosive GERD and Barrett's esophagus.

MATERIALS AND METHODS

This was a retrospective study of dyspeptic patients undergoing upper endoscopy between 2002 and 2013. Following endoscopy, those with previously undiagnosed GERD were sub-grouped into non-erosive GERD (NERD), erosive GERD (eGERD), or Barrett's esophagus. H. pylori status was confirmed by 2 positive tests.

RESULTS

About 5156 patients were included, GERD was present in 65.6% including 1992 with NERD and 1392 with eGERD. About 1772 dyspeptic patients without symptoms of reflux and/or esophagitis served as controls. A hiatal hernia increased the risk of both eGERD and NERD. eGERD was more prevalent among the obese (OR =1.72, p < 0.001), men (OR =1.38, p < 0.001) and current smokers. Helicobacter pylori infection was significantly more common among those with NERD (OR =1.17 versus 1.01, p = 0.046). Logistic regression analysis for eGERD and NERD using age, gender, body mass index, H. pylori infection, hiatal hernia, and smoking showed that overweight and hiatal hernia were significant risk factors for eGERD, and female gender for NERD. Male gender, eGERD and age >50 years were the major risk factors for Barrett's esophagus.

CONCLUSIONS

The epidemiology of eGERD and NERD suggests differences in pathogenesis, and prevention and treatment strategies should be separately examined in men and women.

Role of the gastroenterologist in the management of the obese patient

Obesity is a highly prevalent disease worldwide, and one in which gastroenterologists can play an important role. Some digestive diseases are more common in obese patients, and preoperative evaluation may be required in some cases. Additionally, bariatric surgery can lead to digestive complications in the short and long term that require intervention, and endoscopic treatment can be an important factor in weight loss. The aim of this review is to highlight the role of the gastroenterologist in the management of obese patients who are either scheduled for or have undergone surgical or endoscopic treatment for obesity.

Recurrence and Its Impact on the Health-related Quality of Life in Patients with Gastroesophageal Reflux Disease: A Prospective Follow-up Analysis

Background/Aims

Limited data exist on the outcome of gastroesophageal reflux disease (GERD) treatment and its impact on the health-related quality of life (HRQoL) in the Asian population. This study aims to evaluate the treatment outcomes, to investigate the factors associated with recurrence, and to evaluate the impact of the treatment outcome on the HRQoL in a Korean GERD population.

Methods

This was a prospective, multicenter study involving a total of 824 GERD patients. The response to treatment was assessed at week 4 (or week 8 for the patients who did not achieve complete resolution [CR] at week 4). The EQ-5D questionnaire was used at baseline, end of treatment, and first recurrence to assess the HRQoL. To assess GERD symptoms, contact of patients by phone at 1, 6, and 12 months following treatment was carried out.

Results

CR was achieved in 65.6% and recurrence was observed in 47.8% following treatment. CR and recurrence rates did not differ by the presence of esophagitis. Multivariate analysis revealed that acid regurgitation (odds ratio 2.249; 95% confidence interval 1.293–3.912; P = 0.004) and both acid regurgitation and heartburn (odds ratio 2.330; 95% confidence interval 1.392–3.901; P = 0.001) were independent risk factors for GERD recurrence. EQ-5D scores were more improved in patients with CR than in those without CR, and worsened more during follow-up in patients with recurrence than in those without recurrence.

Conclusions

We should achieve complete symptom relief and attempt to prevent recurrence in GERD patients to improve their HRQoL.

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.

Esophageal abnormalities in morbidly obese adult patients

BACKGROUND

An increase in body mass index has been found to be associated with an increase in the prevalence of gastroesophageal reflux disease (GERD) symptoms, esophageal mucosal injury, and GERD complications. Few systematic studies with objective tests have evaluated esophageal disorders in the morbidly obese population.

OBJECTIVES

To define more precisely in morbidly obese people the incidence of esophageal symptoms and characterize the esophageal disorders using objective data.

SETTING

University Hospital, Spain.

METHODS

Two hundred twenty-four presurgical morbidly obese patients were submitted to a protocol including a clinical history and objective tests (endoscopy, stationary esophageal manometry, 24-hour esophageal pH monitoring and isotopic emptying of the esophagus).

RESULTS

In a morbidly obese population, heartburn (50.9%) and regurgitation (28.6%) were the most prevalent symptoms of GERD. Endoscopy registered hiatus hernia (12.5%) and reflux esophagitis (17.3%). Manometry was often abnormal (33.4%), with a hypotensive lower esophageal sphincter as the most common finding. Esophageal pH-metry was abnormal in 54.2% of the cases. Finally, 9.1% of the patients presented with abnormal isotopic esophageal emptying. A correlation between the degree of obesity and the severity of symptoms/objective tests for esophageal abnormalities could not be found.

CONCLUSIONS

In morbidly obese patients, GERD is common, symptoms are unspecific, and there is a high prevalence of pH-metry and manometric abnormalities, unrelated to the degree of obesity.

Helicobacter pylori-Mediated Protection against Extra-Gastric Immune and Inflammatory Disorders: The Evidence and Controversies

A large number of studies link H. pylori infection with a reduced risk of developing extra-gastric conditions such as allergy, asthma, inflammatory bowel disease, coeliac disease and multiple sclerosis. The strength of the evidence for these protective associations is quite variable, and published studies often do not agree. This review article discusses some of the reasons for these discrepancies, and the difficulties faced when designing studies. Examples of some protective disease associations are described in detail, where the evidence is most abundant and thought to be more reliable. The most convincing of these are supported by published mechanistic data, for example with animal models, or incidence of disease exacerbation in humans following H. pylori eradication. Although controversial, this field is very important as the prevalence of H. pylori is decreasing throughout the world whilst many chronic diseases are becoming more common. These trends are likely to continue in the future, therefore it is important that we fully understand if and how H. pylori confers protection.

Surgical treatment of gastroesophageal reflux disease

Operative treatment of GERD has become more common since the introduction of LARS. Careful patient selection based on symptoms, response to medical therapy, and preoperative testing will optimize the chances for effective and durable postoperative control of symptoms. Complications of the LARS are rare and generally can be managed without reoperation. When reoperation is necessary for failed antireflux surgery, it should be performed by high-volume gastroesophageal surgeons.