Acceleration of Gastric Emptying and Improvement of GERD Outcome After Laparoscopic Sleeve Gastrectomy in Non-diabetic Obese Patients

Incretin impact on gastric function in obesity: physiology, and pharmacological, surgical and endoscopic treatments

The aims of this review are to appraise the role of the stomach in satiation, the effects of incretin and other hormone agonists on weight loss and the role of altered gastric functions in their effects on obesity or glycaemic control. In addition to the gut in its role in enzymatic digestion and hormonal responses to nutrient ingestion, gastric motor functions include accommodation, trituration and emptying [gastric emptying (GE)] of food and elicitation of postprandial satiation and satiety. The postprandially released hormones most extensively studied and utilized therapeutically are glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP). Their mechanisms of action include stimulation of pancreatic β cells to produce insulin. However, GLP-1 reduces glucagon and slows GE, whereas GIP increases glucagon and does not alter GE. Molecular modifications of GLP-1 (which has a T1/2 of 3 min) led to the development of long-acting subcutaneous or oral pharmacological agents that have been approved for the treatment of obesity, and their effects on gastric function are documented. Other medications in development target other molecular mechanisms, including glucagon and amylin. Small-molecule GLP-1 receptor agonists are promising for the treatment of obesity and may also slow GE. Bariatric surgery and endoscopy increase satiation by restricting gastric size; in addition Roux-en-Y gastric bypass and to a lesser extent sleeve gastrectomy (but not endoscopic gastroplasty) increase postprandial circulating incretins, reducing appetite. In conclusion the stomach's function is integral to the impact of the most effective pharmacological and procedural reversal of obesity related to the incretin revolution.

Physiological Archetypes of de novo Gastroesophageal Reflux Disease After Laparoscopic Sleeve Gastrectomy

Laparoscopic Sleeve Gastrectomy (LSG) is the most common bariatric surgery in the world. While clinically effective, recent studies have shown increasingly higher rates of gastroesophageal reflux disease (GERD) and esophageal motility disorders. We reviewed all the literature and unraveled the underlying mechanism of post-LSG GERD. Finally, we propose a new classification to help us understand the disease and guide work-up, treatment, and future refinements in the surgical technique.

Current Status of Anti-Reflux Surgery as a Treatment for GERD

Anti-reflux surgery (ARS) is an efficient treatment option for gastroesophageal reflux disease (GERD). Despite growing evidence of the efficacy and safety of ARS, medications including proton pump inhibitors (PPIs) remain the most commonly administered treatments for GERD. Meanwhile, ARS can be an effective treatment option for patients who need medications continuously or for those who are refractory to PPI treatment, if proper candidates are selected. However, in practice, ARS is often regarded as a last resort for patients who are unresponsive to PPIs. Accumulating ARS-related studies indicate that surgery is equivalent to or better than medical treatment for controlling typical and atypical GERD symptoms. Furthermore, because of overall reduced medication expenses, ARS may be more cost-effective than PPI. Patients are selected for ARS based on endoscopic findings, esophageal acid exposure time, and PPI responsiveness. Although there is limited evidence, ARS may be expanded to include patients with normal acid exposure, such as those with reflux hypersensitivity. Additionally, other factors such as age, body mass index, and comorbidities are known to affect ARS outcomes; and such factors should be considered. Nissen fundoplication or partial fundoplication including Dor fundoplication and Toupet fundoplication can be chosen, depending on whether the patient prioritizes symptom improvement or minimizing postoperative symptoms such as dysphagia. Furthermore, efforts to reduce and manage postoperative complications and create awareness of the long-term efficacy and safety of the ARS are recommended, as well as adequate training programs for new surgeons.

The role of gastric function in control of food intake (and body weight) in relation to obesity, as well as pharmacological and surgical interventions

PURPOSE

The objectives of this review are to summarize the role of gastric motor functions in the development of satiation (defined broadly as postprandial fullness) and satiety (reduced appetite or postponing desire to eat after a meal) and their impact on weight change. The specific topics are the methods of measurement of gastric emptying and accommodation and their impact on food intake, satiation, and satiety. A second focus contrasts bariatric surgery to endoscopic gastroplasty that alter gastric emptying and incretin responses in markedly divergent manners.

BACKGROUND

The hormone, GLP-1, retards gastric emptying and increases gastric accommodation through vagally-mediated effects. Indeed, these effects provide the basis for the association of altered gastric emptying in the appetite and weight loss responses to pharmacological interventions particularly by those acting on receptors of incretin agonists such as liraglutide and the dual agonists, tirzepatide and cotadutide, all of which retard gastric emptying. In fact, retardation of gastric emptying and gastrointestinal adverse effects have been shown to contribute in part to the weight loss in response to this class of pharmacological agents.

SUMMARY

The motor functions of the stomach are relevant to postprandial fullness and to interventions aimed at weight loss in people with obesity.

Meta-analysis of Long-term De Novo Acid Reflux-Related Outcomes Following Sleeve Gastrectomy: Evidence Against the Need for Routine Postoperative Endoscopic Surveillance

OBJECTIVES

To evaluate the incidence of long-term de novo acid reflux-related complications following sleeve gastrectomy (SG) to determine whether routine postoperative surveillance endoscopy is necessary.

METHODS

A systematic search of Medline, Embase, CINAHL, CENTRAL, the Web of Science, and bibliographic reference lists was conducted. A proportion meta-analysis model was constructed to quantify the risk of the de novo gastro-oesophageal reflux disease (GORD), oesophagitis, and Barrett's oesophagus (BE) at least 4 years after SG. Random-effects modelling was applied to calculate pooled outcome data.

RESULTS

Thirty-two observational studies were included reporting a total of 7904 patients who underwent primary SG and were followed up for at least 4 years. The median follow-up period was 60 months (48-132). Preoperative acid-reflux symptoms existed in 19.1% ± 15.1% of the patients. The risk of development of de novo GORD, oesophagitis, and BE after SG was 24.8% (95% CI 18.6-31.0%), 27.9% (95% CI 17.7-38.1%), and 6.7% (95% CI 3.7-9.7%), respectively. The between-study heterogeneity was significant in all outcome syntheses. It was suspected that several of the included studies have not reported BE and oesophagitis because such events might not have happened in their cohorts.

CONCLUSIONS

Long-term risk of de novo GORD after SG seems to be comparable with those of the general population which questions the merit of surveillance endoscopy after SG in asymptomatic patients. De novo BE and oesophagitis after SG have not been reported by most of the available studies which may lead to overestimation of the rates of both outcomes in any evidence synthesis. We recommend endoscopic surveillance for symptomatic patients only.

Irritable bowel syndrome-like symptoms before and after bariatric surgery and association with short-chain fermentable carbohydrates consumption: an observational prospective study

Background and aims

Irritable Bowel Syndrome (IBS)-like symptoms are frequent following bariatric surgery. This study aims to evaluate the frequency of IBS symptoms severity before and after bariatric surgery and their association with short-chain fermentable carbohydrates (FODMAPs) consumption.

Patients and methods

IBS symptoms severity in a cohort of obese patients was evaluated prospectively before, 6 and 12 months after bariatric surgery by validated questionnaires and tools (Irritable Bowel Syndrome Severity Scoring System (IBS SSS), Bristol Stool Scale (BSS), Quality of Life Short- Form-12 (SF-12), Hospital Anxiety and Depression scale (HAD)). FODMAPs consumption and its association with IBS symptom severity was evaluated by using a food frequency questionnaire focused on high-FODMAPs food consumption.

Results

Fifty-one patients were included (41 female; mean age 41 years (SD: 12)), 84% received a sleeve gastrectomy, and 16% a Roux-en-Y gastric bypass. Symptoms compatible with IBS were observed in 43% of patients before surgery, in 58% of patients at 6 months and 33% at 12 months (NS, p-value=0,197 and 0,414). In a multivariate model, a significant association was found between the IBS SSS score and lactose consumption at 6 months (β = + 58, 1; p = 0.03), and with polyols consumption at 12 months (β = + 112,6; p = 0.01).

Conclusions

Mild to moderate IBS symptoms are frequent in obese patients before bariatric surgery. A significant association between lactose and polyols consumption and IBS SSS score was observed after bariatric surgery, suggesting a potential link between the severity of IBS symptoms and some specific FODMAPs consumption.

Systematic review on sleeve gastrectomy or Roux-en-Y gastric bypass surgery for refractory gastroparesis

Management of refractory gastroparesis is challenging after diet, prokinetics, and long-term nutritional support have failed. In this review, the efficacy and safety of surgical interventions (sleeve gastrectomy and Roux-en-Y gastric bypass surgery) are evaluated systematically in patients with refractory gastroparesis. The PubMed, Embase, and Scopus databases were searched to identify relevant studies published up to June 2021. Outcome of interest was symptom improvement and gastric emptying. Nineteen studies with 222 refractory gastroparesis patients (147 Roux-en-Y gastric bypass, 39 sleeve gastrectomy, and 36 subtotal gastrectomy) were included. All studies reported symptom improvement postoperatively, particularly vomiting and nausea. Gastric emptying improved postoperatively in 45% up to 67% for sleeve gastrectomy and 87% for Roux-en-Y gastric bypass. The findings of our systematic review suggest that sleeve gastrectomy and Roux-en-Y gastric bypass surgery improve symptoms and gastric emptying in patients with refractory gastroparesis. Surgery may be effective as treatment for a small group of patients when all other therapies have failed.

Endoscopic Evaluation of De Novo Esophagitis and Barrett's Esophagus, 5 Years After Sleeve Gastrectomy

PURPOSE

Sleeve gastrectomy (SG) is the most common bariatric procedure worldwide. It has been reported that there is a strong association between SG and the development of gastroesophageal reflux disease (GERD) and Barrett's esophagus (BE). This study was conducted to evaluate esophagogastroduodenoscopy (EGD) findings in patients with a history of SG with more than 5-year follow-up.

METHODS

This is a retrospective cohort study of prospectively maintained database. Inclusion criteria included patients who underwent SG between April 2015 and March 2016, aged 18 and above, BMI ≥ 40 kg/m2. Patients with 5 years of follow-up were invited to take part in the study and underwent EGD and biopsy.

RESULTS

One hundred twenty-six patients were recruited with a mean age of 44.6 ± 11.1 years. After a 5-year follow-up, there were 31 (29.5%) patients with reflux esophagitis. The grades of GERD were A, B, and C in 16 (15.2), 12 (11.4), and 3 (2.9%) patients, respectively. Incidence of BE was 5.7% after 5 years from SG. There was a 16.6% lost to follow-up at 5 years after SG.

CONCLUSION

The diagnosis and severity of GERD and the search for BE justify endoscopic surveillance in all long-term post-sleeve patients, regardless of reflux symptoms.

Changes in interstitial cells and gastric excitability in a mouse model of sleeve gastrectomy

Obesity is a critical risk factor of several life-threatening diseases and the prevalence in adults has dramatically increased over the past ten years. In the USA the age-adjusted prevalence of obesity in adults was 42.4%, i.e., with a body mass index (BMI, weight (kg)/height (m)2) that exceeds 30 kg/m2. Obese individuals are at the higher risk of obesity-related diseases, co-morbid conditions, lower quality of life, and increased mortality more than those in the normal BMI range i.e., 18.5-24.9 kg/m2. Surgical treatment continues to be the most efficient and scientifically successful treatment for obese patients. Sleeve gastrectomy or vertical sleeve gastrectomy (VSG) is a relatively new gastric procedure to reduce body weight but is now the most popular bariatric operation. To date there have been few studies examining the changes in the cellular components and pacemaker activity that occur in the gastric wall following VSG and whether normal gastric activity recovers following VSG. In the present study we used a murine model to investigate the chronological changes of gastric excitability including electrophysiological, molecular and morphological changes in the gastric musculature following VSG. There is a significant disruption in specialized interstitial cells of Cajal in the gastric antrum following sleeve gastrectomy. This is associated with a loss of gastric pacemaker activity and post-junctional neuroeffector responses. Over a 4-month recovery period there was a gradual return in interstitial cells of Cajal networks, pacemaker activity and neural responses. These data describe for the first time the changes in gastric interstitial cells of Cajal networks, pacemaker activity and neuroeffector responses and the time-dependent recovery of ICC networks and normalization of motor activity and neural responses following VSG.

Laparoscopic Single Anastomosis Sleeve Ileal Bypass with Follow-up of Weight Loss and Metabolic Impact

Background: Bariatric surgery has been an effective safe management for severe obesity. The newly developed single-anastomosis sleeve ileal (SASI) bypass has shown efficacy as a functional as well as mechanical restrictive bariatric procedure, with a neuroendocrine modulation effect. SASI bypass is still an investigational procedure, hence, more evidence is needed till it is declared as a standard bariatric procedure by the IFSO. Aim of the study: The current work aimed to describe our experience regarding the technical steps, the efficacy and the short-term outcome of SASI bypass procedure in patients with severe obesity. Patients and methods: Forty seven patients with severe obesity underwent SASI bypass procedure. They were followed till 1 year postoperatively. The weight loss, comorbidities and laboratory changes were assessed. Results: Patients evaluation at the 1-year postoperative follow up revealed a mean %TWL of 37.55 ± 6.17 and a mean %EBWL of 76.21 ± 9.8. The remission rates of T2DM, hyperlipidemia and hypertension were 85.7%, 94.7% and 89.66%, respectively, with statistically high significant differences between the preoperative and 1-year postoperative comorbidities rate. Stepwise regression analysis demonstrated that only the preoperative HbA1C remained in the model predicting the %TWL, and the preoperative BMI was the remaining factor in the model predicting the %EBWL in the study patients. Conclusion: The present study adds a new evidence to the promising outcome of the newly introduced SASI bypass procedure. After one year, the study patients showed excellent weight loss and comorbidities remission together with acceptable major complication rates.

Psychotropic Medications in Metabolic and Bariatric Surgery: Research Updates and Clinical Considerations

PURPOSE OF REVIEW

We review evidence for assessing and monitoring psychotropic medications in metabolic and bariatric surgery (MBS) patients. We describe weight gain side effects, potential perioperative risks, pharmacokinetic changes that occur after MBS, and conclude with clinical recommendations.

RECENT FINDINGS

Research on psychiatric medication use and post-MBS weight outcomes is lacking and inconsistent; however, there is consistent evidence that, though variable, psychiatric medication use is associated with weight gain. Several meta-analyses and reviews provide guidance on lowering risk when appropriate. Perioperative lithium toxicity and SSRI discontinuation syndrome also warrant consideration, as do potential post-operative pharmacokinetic changes. In the absence of data for each psychiatric drug classification, close symptom monitoring and, where appropriate, serum concentration monitoring are recommended. MBS patients are a psychiatrically vulnerable population, and many are on psychiatric medications. Given potential weight/metabolic side effects, perioperative complications, and post-operative pharmacokinetic changes that occur with psychotropic medication use, providers should stay well informed on psychiatric medication management considerations.

Effect of laparoscopic sleeve gastrectomy on drug pharmacokinetics

INTRODUCTION

Given its feasibility and efficacy, laparoscopic sleeve gastrectomy (LSG) has become a widely accepted bariatric surgery for patients with clinically diagnosed severe obesity. LSG induces anatomical changes and subsequent weight loss which may affect drug pharmacokinetics (PK) and consequently impact dosing regimens. This review aims to examine the effect of LSG on drug PK and identify relevant gastrointestinal physiological alterations.

AREAS COVERED

PubMed, Embase, Scopus, and the Cochrane Library were searched for articles related to drug PK and LSG from inception to July 2021. Moreover, literature concerning postoperative physiological conditions in the gastrointestinal tract, such as gastric pH, gastric emptying, and small bowel transit time, etc., which may affect the PK profile of drug products was also reviewed.

EXPERT OPINION

Although LSG is classified as having restrictive property without malabsorptive bypass, postoperative changes in gastrointestinal physiology and subsequent weight loss may also lead to increased, decreased or unaltered drug exposure levels. General monitoring on drug efficacy or safety using biomarkers is proposed. In addition, therapeutic drug monitoring for those drugs when it is applicable and available is recommended to ensure efficient drug dosing and avoid adverse effects. Further research into many individual drugs are warranted.

Impact on sleeve gastrectomy in patients with esophageal motor disorder

BACKGROUND

Gastroesophageal reflux disease (GERD) and esophageal motor disorders (EMD) are frequent conditions among patients with obesity. The effects of sleeve gastrectomy (SG) on esophageal function can worsen GERD, but little is known about its effects on EMD and the consequences of preexisting EMD on GERD after SG.

OBJECTIVES

To study the postoperative outcomes of SG in a population of patients displaying preexisting EMD.

SETTING

University Hospital, France.

METHODS

Patients with EMD confirmed by high-resolution manometry who underwent a laparoscopic SG between 2010 and 2019 were retrospectively included in this monocenter study. GERD symptoms and high-resolution manometry results were recorded before surgery and during follow-up. Conversion to gastric bypass were also recorded.

RESULTS

Thirty-seven patients were included. Mean age was 52.6 ± 12.9 years. Most patients were female (70%). EMD were achalasia (19% of patients), hypercontractile (22%), hypocontractile (30%) and nutcracker esophagus (22%), and ineffective esophageal motility (8%). GERD symptoms were present in 10 patients (27%) preoperatively and 18 (49%) postoperatively. Achalasia was not resolved after SG and was constantly associated with disabling food blockage or GERD symptoms after surgery, and 3 of 4 patients with nutcracker esophagus had postoperative GERD symptoms and underwent gastric bypass.

CONCLUSIONS

This study is the largest to describe the course of GERD and EMD after SG in patients displaying preoperative EMD. Achalasia and nutcracker esophagus are associated with poorer postoperative outcomes, and another procedure such as a gastric bypass should be performed.

Gastric Sensory and Motor Functions and Energy Intake in Health and Obesity-Therapeutic Implications

Sensory and motor functions of the stomach, including gastric emptying and accommodation, have significant effects on energy consumption and appetite. Obesity is characterized by energy imbalance; altered gastric functions, such as rapid gastric emptying and large fasting gastric volume in obesity, may result in increased food intake prior to reaching usual fullness and increased appetite. Thus, many different interventions for obesity, including different diets, anti-obesity medications, bariatric endoscopy, and surgery, alter gastric functions and gastrointestinal motility. In this review, we focus on the role of the gastric and intestinal functions in food intake, pathophysiology of obesity, and obesity management.