Scintigraphic evaluation of gastric emptying in obese patients submitted to sleeve gastrectomy compared to normal subjects. Obes Surg. 2009;19:1515-1521. [PMID: 19714384 DOI: 10.1007/s11695-009-9954-z]

The Potential Mechanism of Remission in Type 2 Diabetes Mellitus After Vertical Sleeve Gastrectomy

In recent years, there has been a gradual increase in the prevalence of obesity and type 2 diabetes mellitus (T2DM), with bariatric surgery remaining the most effective treatment strategy for these conditions. Vertical sleeve gastrectomy (VSG) has emerged as the most popular surgical procedure for bariatric/metabolic surgeries, effectively promoting weight loss and improving or curing T2DM. The alterations in the gastrointestinal tract following VSG may improve insulin secretion and resistance by increasing incretin secretion (especially GLP-1), modifying the gut microbiota composition, and through mechanisms dependent on weight loss. This review focuses on the potential mechanisms through which the enhanced action of incretin and metabolic changes in the digestive system after VSG may contribute to the remission of T2DM.

Outcomes and Management of Re-Establishing Bariatric Patients

BACKGROUND

Lifelong follow-up after metabolic and bariatric surgery (MBS) is necessary to monitor for patient outcomes and nutritional status. However, many patients do not routinely follow-up with their MBS team. We studied what prompted MBS patients to seek bariatric care after being lost to follow-up and the subsequent treatments they received.

STUDY DESIGN

A retrospective cohort study of patients after MBS who had discontinued regular MBS follow-up but represented to the MBS clinic between July 2018 and December 2022 to re-establish care. Patients with a history of a sleeve gastrectomy (SG), Roux-En-Y gastric bypass (RYGB), and adjustable gastric banding (AGB) were included.

RESULTS

We identified 400 patients (83.5% women, mean age 50.3 ± 12.2 years at the time of re-establishment of bariatric care), of whom 177 (44.3%) had RYGB, 154 (38.5%) had SG, and 69 (17.2%) had AGB. Overall, recurrent weight gain was the most common reason for presentation for all three procedures (81.2% in SG, 62.7% in RYGB, and 65.2% in AGB; p < 0.001). Patients who underwent SG were more likely to undergo a revision MBS compared with patients who underwent RYGB (16.9% vs 5.8%, p < 0.001), whereas patients who underwent RYGB were more likely to undergo an endoscopic intervention than patients who underwent SG (17.5% vs 7.8%, p < 0.001). The response to antiobesity medication agents, specifically glucagon-like peptide-1 receptor agonists drugs, was better in patients who underwent RYGB, than that in patients who underwent SG.

CONCLUSIONS

This study highlights recurrent weight gain as the most common reason for patients after MBS seeking to re-establish care with the MBS team. SG had a higher rate of revision MBS than RYGB, whereas endoscopic interventions were performed more frequently in the RYGB group. Antiobesity medication agents, especially glucagon-like peptide-1 receptor agonists drugs, were more effective in patients who underwent RYGB.

Gastrointestinal Permeability After Bariatric Surgery: A Systematic Review

Gastrointestinal permeability refers to the movement of substances across the gut wall. This is mediated by endotoxemia (bacterial products entering the systemic circulation), and is associated with metabolic disease. The effect of bariatric surgery on permeability remains uncertain; the associated dietary, metabolic and weight changes are suggested to influence, or trigger, altered permeability. The primary aim of this study is to synthesize evidence and analyze the effect of bariatric surgery on permeability. A systematic review was performed, searching MEDLINE, EMBASE, and Scopus until February 2023, using MESH terms "intestinal permeability", "bariatric", for studies reporting in vivo assessment of permeability. Three cohort studies and two case series were identified (n=96). Data was heterogeneous; methodology and controls preclude meta-analysis. Gastroduodenal permeability reduced post-sleeve gastrectomy (SG). Two studies showed an increase in small intestinal permeability after biliopancreatic diversion. Two studies revealed a decrease in post-Roux-en-Y gastric bypass. One study identified increased colonic permeability six months post-SG. Evidence regarding permeability change after bariatric surgery is conflicting, notably for the small intestine. Impaired colonic permeability post-SG raises concerns regarding colonic protein fermentation and harmful dietary sequelae. There are multiple interacting variables confounding gastrointestinal permeability change; procedure type, altered microbiota and metabolic response to surgery. Further understanding of this important aspect of obesity is required, both before and after bariatric surgery.

In Vitro Human Gastrointestinal Tract Simulation Systems: A Panoramic Review

Simulated human gastrointestinal (GI) tract systems are important for their applications in the fields of probiotics, nutrition and health. To date, various in vitro gut systems have been available to study GI tract dynamics and its association with health. In contrast to in vivo investigations, which are constrained by ethical considerations, in vitro models have several benefits despite the challenges involved in mimicking the GI environment. These in vitro models can be used for a range of research, from simple to dynamic, with one compartment to several compartments. In this review, we present a panoramic development of in vitro GI models for the first time through an evolutionary timeline. We tried to provide insight on designing an in vitro gut model, especially for novices. Latest developments and scope for improvement based on the limitations of the existing models were highlighted. In conclusion, designing an in vitro GI model suitable for a particular application is a multifaceted task. The bio-mimicking of the GI tract specific to geometrical, anatomical and mechanical features remains a challenge for the development of effective in vitro GI models. Advances in computer technology, artificial intelligence and nanotechnology are going to be revolutionary for further development. Besides this, in silico high-throughput technologies and miniaturisation are key players in the success of making in vitro modelling cost-effective and reducing the burden of in vivo studies.

Alteration in the gut microbiome is associated with changes in bone metabolism after laparoscopic sleeve gastrectomy

Laparoscopic sleeve gastrectomy (LSG), the most common bariatric surgical procedure, leads to durable weight loss and improves obesity-related comorbidities. However, it induces abnormalities in bone metabolism. One unexplored potential contributor is the gut microbiome, which influences bone metabolism and is altered after surgery. We characterized the relationship between the gut microbiome and skeletal health in severe obesity and after LSG. In a prospective cohort study, 23 adults with severe obesity underwent skeletal health assessment and stool collection preoperatively and 6 mo after LSG. Gut microbial diversity and composition were characterized using 16S rRNA gene sequencing, and fecal concentrations of short-chain fatty acids (SCFA) were measured with LC-MS/MS. Spearman's correlations and PERMANOVA analyses were applied to assess relationships between the gut microbiome and bone health measures including serum bone turnover markers (C-terminal telopeptide of type 1 collagen [CTx] and procollagen type 1 N-terminal propeptide [P1NP]), areal BMD, intestinal calcium absorption, and calciotropic hormones. Six months after LSG, CTx and P1NP increased (by median 188% and 61%, P < .01) and femoral neck BMD decreased (mean -3.3%, P < .01). Concurrently, there was a decrease in relative abundance of the phylum Firmicutes. Although there were no change in overall microbial diversity or fecal SCFA concentrations after LSG, those with greater within-subject change in gut community microbial composition (β-diversity) postoperatively had greater increases in P1NP level (ρ = 0.48, P = .02) and greater bone loss at the femoral neck (ρ = -0.43, P = .04). In addition, within-participant shifts in microbial richness/evenness (α-diversity) were associated with changes in IGF-1 levels (ρ = 0.56, P < .01). The lower the postoperative fecal butyrate concentration, the lower the IGF-1 level (ρ = 0.43, P = .04). Meanwhile, the larger the decrease in butyrate concentration, the higher the postoperative CTx (ρ = -0.43, P = .04). These findings suggest that LSG-induced gut microbiome alteration may influence skeletal outcomes postoperatively, and microbial influences on butyrate formation and IGF-1 are possible mechanisms.

Vertical sleeve gastrectomy improves glucose-insulin homeostasis by enhancing β-cell function and survival via FGF15/19

Vertical sleeve gastrectomy (VSG) restores glucose homeostasis in obese mice and humans. In addition, the increased fibroblast growth factor (FGF)15/19 circulating level postsurgery has been implicated in this effect. However, the impact of FGF15/19 on pancreatic islets remains unclear. Using a diet-induced obese mice model, we demonstrate that VSG attenuates insulin hypersecretion in isolated pancreatic islets, likely due to morphological alterations in the endocrine pancreas such as reduction in islet, β-cell, and α-cell mass. In addition, VSG relieves gene expression of endoplasmic reticulum (ER) stress and inflammation markers in islets from obese mice. Incubation of INS-1E β-cells with serum from obese mice induced dysfunction and cell death, whereas these conditions were not induced with serum from obese mice submitted to VSG, implicating the involvement of a humoral factor. Indeed, VSG increased FGF15 circulating levels in obese mice, as well as the expression of FGF receptor 1 (Fgfr1) and its coreceptor β-klotho (Klb), both in pancreatic islets from VSG mice and in INS-1E cells treated with the serum from these mice. Moreover, exposing INS-1E cells to an FGFR inhibitor abolished the effects of VSG serum on insulin secretion and cell death. Also, recombinant FGF19 prevents INS-1E cells from dysfunction and death induced by serum from obese mice. These findings indicate that the amelioration of glucose-insulin homeostasis promoted by VSG is mediated, at least in part, by FGF15/19. Therefore, approaches promoting FGF15/19 release or action may restore pancreatic islet function in obesity.NEW & NOTEWORTHY Vertical sleeve gastrectomy (VSG) decreases insulin secretion, endoplasmic reticulum (ER) stress, and inflammation in pancreatic islets from obese mice. In addition, VSG increased fibroblast growth factor (FGF)15 circulating levels in obese mice, as well as the expression of FGF receptor 1 (Fgfr1) and its coreceptor β-klotho (Klb), both in pancreatic islets from VSG mice and in INS-1E β-cells treated with the serum from these mice. Serum from operated mice protects INS-1E cells from dysfunction and apoptosis, which was mediated by FGF15/19.

Differential effect of gastric bypass versus sleeve gastrectomy on insulinotropic action of endogenous incretins

OBJECTIVE

Prandial hyperinsulinemia after Roux-en-Y gastric bypass surgery (GB), and to lesser degree after sleeve gastrectomy (SG), has been attributed to rapid glucose flux from the gut and increased insulinotropic gut hormones. However, β-cell sensitivity to exogenous incretin is reduced after GB. This study examines the effect of GB versus SG on prandial glycemia and β-cell response to increasing concentrations of endogenous incretins.

METHODS

Glucose kinetics, insulin secretion rate (ISR), and incretin responses to 50-g oral glucose ingestion were compared between ten nondiabetic participants with GB versus nine matched individuals with SG and seven nonoperated normal glucose tolerant control individuals (CN) with and without administration of 200 mg of sitagliptin.

RESULTS

Fasting glucose and hormonal levels were similar among three groups. Increasing plasma concentrations of endogenous incretins by two- to three-fold diminished prandial glycemia and increased β-cell secretion in all three groups (p < 0.05), but insulin secretion per insulin sensitivity (i.e., disposition index) was increased only in GB (p < 0.05 for interaction). However, plot of the slope of ISR (from premeal to peak values) versus plasma glucagon-like peptide-1 concentration was smaller after GB compared with SG and CN.

CONCLUSIONS

After GB, increasing incretin activity augments prandial β-cell response whereas the β-cell sensitivity to increasing plasma concentrations of endogenous incretin is diminished.

Impact of Sleeve Gastrectomy on Fecal Microbiota in Individuals with Morbid Obesity

BACKGROUND

The intestinal microbiota plays an important role in the etiology of obesity. Sleeve gastrectomy (SG) is a frequently performed and effective therapy for morbid obesity.

OBJECTIVE

To investigate the effect of sleeve gastrectomy on the fecal microbiota of individuals with morbid obesity and to examine whether shifts in microbiota composition are associated with markers of inflammation and intestinal barrier function.

METHODS

Fecal and blood samples of healthy individuals (n = 27) and morbidly obese individuals pre-SG (n = 24), and at 2 months (n = 13) and 6 months post-SG (n = 9) were collected. The 16SrRNA gene was sequenced to assess microbiota composition. Fecal calprotectin, plasma inflammatory markers and intestinal permeability markers (multi-sugar test) were determined.

RESULTS

Fecal microbiota composition between morbidly obese and lean individuals was significantly different. The fecal microbiota composition changed significantly 2 and 6 months post-SG (p = 0.008) compared to pre-SG but not towards a more lean profile. The post-SG microbiota profile was characterized by an increase in facultative anaerobic bacteria, characteristic for the upper gastrointestinal tract. No correlations were found between inflammatory markers, intestinal permeability and microbial profile changes.

CONCLUSIONS

Fecal microbiota composition in morbidly obese individuals changed significantly following SG. This change might be explained by functional changes induced by the SG procedure.

Diagnosis and management of post-bariatric surgery hypoglycemia

INTRODUCTION

While bariatric surgery remains the most effective treatment for obesity that allows substantial weight loss with improvement and possibly remission of obesity-associated comorbidities, some postoperative complications may occur. Managing physicians need to be familiar with the common problems to ensure timely and effective management. Of these complications, postoperative hypoglycemia is an increasingly recognized complication of bariatric surgery that remains underreported and underdiagnosed.

AREA COVERED

This article highlights the importance of identifying hypoglycemia in patients with a history of bariatric surgery, reviews pathophysiology and addresses available nutritional, pharmacological and surgical management options. Systemic evaluation including careful history taking, confirmation of hypoglycemia and biochemical assessment is essential to establish accurate diagnosis. Understanding the weight-dependent and weight-independent mechanisms of improved postoperative glycemic control can provide better insight into the causes of the exaggerated responses that lead to postoperative hypoglycemia.

EXPERT OPINION

Management of post-operative hypoglycemia can be challenging and requires a multidisciplinary approach. While dietary modification is the mainstay of treatment for most patients, some patients may benefit from pharmacotherapy (e.g. GLP-1 receptor antagonist); Surgery (e.g. reversal of gastric bypass) is reserved for unresponsive severe cases. Additional research is needed to understand the underlying pathophysiology with a primary aim in optimizing diagnostics and treatment options.

Changes in Oesophageal Transit, Macro-Reflux Events, and Gastric Emptying Correlate with Improvements in Gastro-Intestinal Symptoms and Food Tolerance Early Post Sleeve Gastrectomy

PURPOSE

There are significant alterations in gastro-intestinal function, food tolerance, and symptoms following sleeve gastrectomy (SG). These substantially change over the first year, but it is unclear what the underlying physiological basis for these changes is. We examined changes in oesophageal transit and gastric emptying and how these correlate with changes in gastro-intestinal symptoms and food tolerance.

MATERIAL AND METHODS

Post-SG patients undertook protocolised nuclear scintigraphy imaging along with a clinical questionnaire at 6 weeks, 6 months, and 12 months.

RESULTS

Thirteen patients were studied: mean age (44.8 ± 8.5 years), 76.9% females, pre-operative BMI (46.9 ± 6.7 kg/m2). Post-operative %TWL was 11.9 ± 5.1% (6 weeks) and 32.2 ± 10.1% (12 months), p-value < 0.0001. There was a substantial increase of meal within the proximal stomach; 22.3% (IQR 12%) (6 weeks) vs. 34.2% (IQR 19.7%) (12 months), p = 0.038. Hyper-accelerated transit into the small bowel decreased from 6 weeks 49.6% (IQR 10.8%) to 42.7% (IQR 20.5%) 12 months, p = 0.022. Gastric emptying half-time increased from 6 weeks 19 (IQR 8.5) to 12 months 27 (IQR 11.5) min, p = 0.027. The incidence of deglutitive reflux of semi-solids decreased over time; 46.2% (6 weeks) vs. 18.2% (12 months), p-value < 0.0001. Reflux score of 10.6 ± 7.6 at 6 weeks vs. 3.5 ± 4.4 at 12 months, (p = 0.049) and regurgitation score of 9.9 ± 3.3 at 6 weeks vs. 6.5 ± 1.7, p = 0.021 significantly reduced.

CONCLUSIONS

These data demonstrate that there is an increase in the capacity of the proximal gastric sleeve to accommodate substrate over the first year. Gastric emptying remains rapid but reduce over time, correlating with improved food tolerance and reduced reflux symptoms. This is likely the physiological basis for the changes in symptoms and food tolerance observed early post-SG.

Dumping syndrome after bariatric surgery: prevalence, pathophysiology and role in weight reduction - a systematic review

Background

Dumping syndrome is a frequent and wellknown adverse event after bariatric surgery and covers a dynamic spectrum of early and late dumping. Accelerated gastric emptying is generally considered to be the cause of gastrointestinal and vasomotor complaints. However, there is much uncertainty regarding the exact pathophysiology of dumping. It has been speculated that the syndrome is a desired consequence of bariatric surgery and contributes to more efficient weight loss, but supporting data are scarce.

Methods

A systematic search was conducted in PubMed in July-August 2021. The prevalence of dumping after the most frequently performed bariatric procedures was analyzed, as well as underlying pathophysiology and its role in weight reduction.

Results

Roux-en-Y gastric bypass (RYGB) is associated with the highest postoperative prevalence of dumping. The fast transit induces neurohumoral changes which contribute to an imbalance between postprandial glucose and insulin levels, resulting in hypoglycemia which is the hallmark of late dumping. Early dumping can, when received in a positive way, become a tool to maintain a strict dietary pattern, but no significant relationship to the degree of weight loss has been shown. However, late dumping is detrimental and promotes overall higher caloric intake.

Conclusion

Dumping syndrome is common after bariatric surgery, especially after RYGB. The pathophysiology is complex and ambiguous. Currently available data do not support dumping as a necessary condition to induce weight loss after bariatric surgery.

Insulinotropic effect of endogenous incretins is greater after gastric bypass than sleeve gastrectomy despite diminished beta-cell sensitivity to plasma incretins

BACKGROUND/AIMS

Prandial hyperinsulinemia after Roux-en Y gastric bypass surgery (GB), and to lesser degree after sleeve gastrectomy (SG), has been attributed to rapid glucose flux from the gut and increased insulinotropic gut hormones. However, β-cell sensitivity to exogenous incretin is markedly reduced after GB. This study examines the effect of GB versus SG on prandial glycemia and β-cell response to increasing concentrations of endogenous incretins.

METHODS

Glucose kinetics, insulin secretion rate (ISR), and incretin responses to 50-gram oral glucose ingestion were compared between 10 non-diabetic subjects with GB versus 9 matched individuals with SG and 7 non-operated normal glucose tolerant controls (CN) on two days with and without administration of 200 mg sitagliptin.

RESULTS

Fasting glucose and hormonal levels were similar among 3 groups. Increasing plasma concentrations of endogenous incretins by 2-3-fold diminished post-OGTT glycemia and increased β-cell secretion in all 3 groups (p<0.05), but insulin secretion per insulin sensitivity (i.e., disposition index) was increased only in GB (p<0.05 for interaction). As a result, sitagliptin administration led to hypoglycemia in 3 of 10 GB. Yet, plot of the slope of ISR versus the increase in endogenous incretin concentration was smaller after GB compared to both SG and CN.

CONCLUSION

Augmented glycemic-induced β-cell response caused by enhanced incretin activity is unique to GB and not shared with SG. However, the β-cell sensitivity to increasing concentrations of endogenous incretin is smaller after bariatric surgery, particularly after GB, compared to non-operated controls, indicating a long-term adaptation of gut-pancreas axis after these procedures.

HIGHLIGHTS

What is known?: Glycemic effects of gastric bypass (GB) and sleeve gastrectomy (SG) is attributed to rapid nutrient flux and enhanced insulinotropic effects of gut hormones but β-cell sensitivity to exogenous GLP-1 or GIP is diminished after GB. What the present findings add?: Post-OGTT β-cell sensitivity to enhanced endogenous incretins by DPP4i is markedly reduced in bariatric subjects versus non-operated controls, and yet insulin secretory response (disposition index) is increased leading to hypoglycemia in GB and not SG. Significance?: Blunted sensitivity to GLP-1 may represent β-cell adaptation to massive elevation in GLP-1 secretion following bariatric surgery to protect against hypoglycemia.The differential effect of enhanced concentrations of incretins on post-OGTT insulin response (disposition index) among GB versus SG highlights a distinct adaptive process among the two procedures.Augmented insulinotropic effects of gut hormones on postprandial insulin secretory response after GB despite a reduced beta-cell sensitivity to plasma concentrations of GLP-1 makes a case for non-hormonal mechanisms of GLP-1 action after GB.Better understanding of long-term effects of bariatric surgery on gut-pancreas axis activity is critical in development of GLP-1-based strategies to address glucose abnormalities (both hyperglycemia and hypoglycemia) in these settings.

Gastroparesis: An Evidence-Based Review for the Bariatric and Foregut Surgeon

Gastroparesis is a gastric motility disorder characterized by delayed gastric emptying. It is a rare disease and difficult to treat effectively; management is a dilemma for gastroenterologists and surgeons alike. We conducted a systematic review of the literature to evaluate current diagnostic tools as well as treatment options. We describe key elements in the pathophysiology of the disease, in addition to current evidence on treatment alternatives, including nutritional considerations, medical and surgical options, and related outcomes.

Intestinal Calcium Absorption Decreases After Laparoscopic Sleeve Gastrectomy Despite Optimization of Vitamin D Status

CONTEXT

Laparoscopic sleeve gastrectomy (LSG), now the most commonly performed bariatric operation, is a highly effective treatment for obesity. While Roux-en-Y gastric bypass is known to impair intestinal fractional calcium absorption (FCA) and negatively affect bone metabolism, LSG's effects on calcium homeostasis and bone health have not been well characterized.

OBJECTIVE

We determined the effect of LSG on FCA, while maintaining robust 25-hydroxyvitamin D (25OHD) levels and recommended calcium intake.

DESIGN, SETTING, PARTICIPANTS

Prospective pre-post observational cohort study of 35 women and men with severe obesity undergoing LSG.

MAIN OUTCOMES

FCA was measured preoperatively and 6 months postoperatively with a gold-standard dual stable isotope method. Other measures included calciotropic hormones, bone turnover markers, and bone mineral density (BMD) by dual-energy X-ray absorptiometry and quantitative computed tomography.

RESULTS

Mean ± SD FCA decreased from 31.4 ± 15.4% preoperatively to 16.1 ± 12.3% postoperatively (P < 0.01), while median (interquartile range) 25OHD levels were 39 (32-46) ng/mL and 36 (30-46) ng/mL, respectively. Concurrently, median 1,25-dihydroxyvitamin D level increased from 60 (50-82) pg/mL to 86 (72-107) pg/mL (P < 0.01), without significant changes in parathyroid hormone or 24-hour urinary calcium levels. Bone turnover marker levels increased substantially, and areal BMD decreased at the proximal femur. Those with lower postoperative FCA had greater areal BMD loss at the total hip (ρ = 0.45, P < 0.01).

CONCLUSIONS

FCA decreases after LSG, with a concurrent rise in bone turnover marker levels and decline in BMD, despite robust 25OHD levels and with recommended calcium intake. Decline in FCA could contribute to negative skeletal effects following LSG.

Delayed Gastric Emptying After Sleeve Gastrectomy Is Associated with Poor Weight Loss

Background

Intermediate to long-term weight regain is a major challenge following sleeve gastrectomy (SG). Physiological changes that mediate the extent of weight loss remain unclear. We aimed to determine if there were specific esophago-gastric transit and emptying alterations associated with weight regain.

Material and Methods

Participants greater than 12 months post-SG were categorized into optimal (n = 29) and poor weight loss (PWL) (n = 72). All patients underwent a liquid contrast barium swallow demonstrating normal post-surgical anatomy and a protocolized nuclear scintigraphy designed specifically to characterize gastric emptying following SG.

Results

The %total weight loss in the optimal group was 26.2 ± 10.5 vs. 14.3 ± 8.8% in the PWL group (p = 0.001). Scintigraphy showed PWL had relatively increased gastric emptying half-time (GE 1/2t) 35 (IQR 23) min vs 19 (IQR 5.5) min (p = 0.001). The multivariate regressions delineated GE 1/2t as the best diagnostic measure for PWL (OR 1.16; CI 1.04–1.29, p-value 0.021). The probability of PWL increased by 16% for every 1-min increase above 21 min of GE 1/2t. A threshold of 21 min was found to have 88% sensitivity and 69% specificity predicting poor weight loss.

Conclusion

Gastric emptying half-times greater than 21 min appear to reliably correlate with poor weight loss following SG. Additionally, further elevations above 21 min in emptying half-time increase the risk of poor weight loss. We have shown nuclear scintigraphy represents a simple and accurate diagnostic tool in patients who experience poor weight loss after SG, provided substantially altered reporting references in interpreting nuclear scintigraphy are applied.

Graphical abstract

Impact of biliopancreatic diversion with duodenal switch on glucose homeostasis and gut hormones and their correlations with appetite

BACKGROUND

Biliopancreatic diversion with duodenal switch (BPD/DS) results in lifelong changes in gastrointestinal physiology with unclear associations with appetite perception.

OBJECTIVE

To explore mixed meal-induced changes in glucose homeostasis and gut hormones and their correlations with appetite perception.

SETTING

University hospital.

METHODS

Of 28 patients studied preoperatively (age: 38.4 ± 11.3 years; body mass index [BMI]: 56.5 ± 5.1 kg/m²; 14 women), 19 (68%) returned for postoperative follow-up. Plasma was sampled for 180 minutes during a 260-kcal standardized mixed meal. Concentrations of leptin, glucose, insulin, triglycerides, active acyl-ghrelin, motilin, total glucose-dependent insulinotropic polypeptide (GIP), active glucagon-like peptide 1 (GLP-1), and total peptide YY (PYY) were measured. Subjective appetite sensations were scored.

RESULTS

BPD/DS resulted in 66.1% ± 23.3% excess BMI loss. Leptin was halved. Glucose and insulin levels were reduced, blunting a preoperative peak at 30 minutes, giving a lower homeostasis model assessment for insulin resistance (HOMA-IR; 13.9 versus 4.8). In contrast, reduced ghrelin and motilin concentrations were accompanied by pronounced peaks 20-30 minutes prior to meal responses. GIP was reduced, whereas GLP-1 and PYY responses were markedly increased, with an early postprandial peak (P < .05, for all). HOMA-IR correlated with insulin (r = .72) and GIP (r = .57). Postoperatively, satiety correlated with GLP-1 (r = .56), whereas the gastric motility index correlated with the desire to eat (r = .60), percentage excess BMI loss (r = -.55), and percentage total weight loss (r = -.49). Delta insulin, GLP-1, and leptin correlated positively with percentage total weight loss (r = .51, r = .48, and r = .58, respectively).

CONCLUSIONS

BPD/DS reduces leptin, HOMA-IR, and GIP while markedly increasing GLP-1 and PYY. This study marks the magnitude change in GLP-1 with additional effects of PYY as important factors for weight loss.

Delayed Gastric Emptying After Sleeve Gastrectomy Is Associated with Poor Weight Loss

Background

Intermediate to long-term weight regain is a major challenge following sleeve gastrectomy (SG). Physiological changes that mediate the extent of weight loss remain unclear. We aimed to determine if there were specific esophago-gastric transit and emptying alterations associated with weight regain.

Material and Methods

Participants greater than 12 months post-SG were categorized into optimal (n = 29) and poor weight loss (PWL) (n = 72). All patients underwent a liquid contrast barium swallow demonstrating normal post-surgical anatomy and a protocolized nuclear scintigraphy designed specifically to characterize gastric emptying following SG.

Results

The %total weight loss in the optimal group was 26.2 ± 10.5 vs. 14.3 ± 8.8% in the PWL group (p = 0.001). Scintigraphy showed PWL had relatively increased gastric emptying half-time (GE ^1/2t) 35 (IQR 23) min vs 19 (IQR 5.5) min (p = 0.001). The multivariate regressions delineated GE ^1/2t as the best diagnostic measure for PWL (OR 1.16; CI 1.04–1.29, p-value 0.021). The probability of PWL increased by 16% for every 1-min increase above 21 min of GE ^1/2t. A threshold of 21 min was found to have 88% sensitivity and 69% specificity predicting poor weight loss.

Conclusion

Gastric emptying half-times greater than 21 min appear to reliably correlate with poor weight loss following SG. Additionally, further elevations above 21 min in emptying half-time increase the risk of poor weight loss. We have shown nuclear scintigraphy represents a simple and accurate diagnostic tool in patients who experience poor weight loss after SG, provided substantially altered reporting references in interpreting nuclear scintigraphy are applied.

Graphical abstract

Does Gastric Expansibility Affect Weight Loss Success After Laparoscopic Sleeve Gastrectomy?

Reduced excess weight loss (EWL) or regain is a worrying problem after metabolic surgery. Factors attainable from the resected specimen that can predict this outcome are investigated. We retrospectively analyzed 64 patients who had undergone laparoscopic sleeve gastrectomy. We collected demographic data, preoperative gastric emptying measurements, volume, expansion capacity, and 6-dimensional measurements of sleeve gastrectomy specimens. Correlations between EWL, body mass index levels, and gastric specimen measurements related to gastric remnant dimensions were also scrutinized. We found a significant correlation between the gastric specimen and remnant gastric volume, the resection line length in the gastric specimen, and 12th-month EWL%. Antrum expansibility was significantly increased in patients with weight regain. There was also a negative correlation between weight loss and age at postoperative first and third years. Sleeve resection line measurement and resected antrum diameter measurements can be used to predict weight loss, especially in the first year postoperatively.

Antrum Preservation Versus Antrum Resection in Laparoscopic Sleeve Gastrectomy With Effects on Gastric Emptying, Body Mass Index, and Type II Diabetes Remission in Diabetic Patients With Body Mass Index 30-40 kg/m2: a Randomized Controlled Study

Background

Laparoscopic sleeve gastrectomy (LSG) is a widely performed procedure nowadays. There is a controversy on whether antrum resection (AR) or antrum preservation (AP) should be done and if this has an effect on BMI, gastric emptying, and associated medical conditions such as diabetes mellitus (DM).

Study Design

This randomized controlled trial included 56 patients in the AP group and 53 patients in the AR group with BMI 30–40 kg/m². Weight, BMI, fasting and postprandial blood glucose (FBS and PPBS), HbA1C, oral hypoglycemic drug use, and % gastric emptying by gastric scintigraphy at 30, 60, 90, and 120 min were recorded preoperatively and postoperatively at 3, 6, and 12 months. Postoperative % of total weight loss (TWL) and symptoms of de novo GERD were observed at 3, 6, and 12 months.

Results

The AR group had significantly lower BMI and HbA1C and higher %TWL than the AP group. There was a significant difference between the two groups regarding % of gastric emptying with the AP group showing higher values at 30, 60, 90, and 120 min. There were no significant differences regarding FBS, PPBS, and oral hypoglycemic use. The AR group had more incidence of GERD symptoms postoperatively yet with no significant difference.

Conclusion

LSG with antrum resection (2 cm from the pylorus) had significantly less postoperative BMI, higher %TWL, better control of type II DM, and more retention of gastric contents in patients with BMI 30–40 kg/m² in comparison with LSG with antral preservation with non-significant increase in incidence of GERD symptoms.

Graphical abstract

Nutrients handling after bariatric surgery, the role of gastrointestinal adaptation

Bariatric surgery determines a rearrangement of the gastrointestinal tract that influences nutrient handling and plays a role in the metabolic changes observed after surgery. Most of the changes depend on the accelerated gastric emptying observed in Roux-en-Y gastric bypass (RYGB) and, to a lesser extent, in sleeve gastrectomy (SG). The rapid delivery of meal into the jejunum, particularly after RYGB, contributes to the prompt appearance of glucose in peripheral circulation. Glucose increase is the principal determinant of GLP-1 increase with the consequent stimulation of insulin secretion, the latter balanced by a paradoxical glucagon increase that stimulates EGP to prevent hypoglycaemia. Protein digestion and amino acid absorption appear accelerated after RYGB but not after SG. After RYGB, the adaptation of the gut to the new condition participates to the metabolic change. The intestinal transit is delayed, the gut microbioma is changed, the epithelium becomes hypertrophic and increases the expression of glucose transporter and of the number of cell secreting hormones. These changes are not observed after SG. After RYGB-less after SG-bile acids (BA) increase, influencing glucose metabolism probably modulating FXR and TGR5 with an effect on insulin sensitivity. Muscle, hepatic and adipose tissue insulin sensitivity improve, and the gut reinforces the recovery of IS by enhancing glucose uptake and through the effect of the BA. The intestinal changes observed after RYGB result in a light malabsorption of lipid but not of carbohydrate and protein. In conclusion, functional and morphological adaptations of the gut after RYGB and SG activate inter-organs cross-talk that modulates the metabolic changes observed after surgery.Level of evidence Level V, narrative literature review.

The Impact of Sleeve Gastrectomy on Gastroesophageal Reflux Disease in Patients with Morbid Obesity

INTRODUCTION

The impact of laparoscopic sleeve gastrectomy (LSG) on gastroesophageal reflux disease (GERD) has not been widely quantified, and the data in the literature remain controversial.

MATERIALS AND METHODS

Candidates for LSG underwent barium swallow, esophageal manometry, ambulatory 24-h esophageal pH monitoring (APM), and gastric emptying scintigraphy before and after surgery (1 and 18 months). Symptoms were evaluated using a gastroesophageal reflux disease questionnaire (GERDq). Esophagogastroduodenoscopy was performed preoperatively in all patients and at 18 months postoperatively in patients who had suffered from preoperative esophagitis.

RESULTS

Fifty-two patients were included in the study (64.4% women and 34.6% men) with a median age of 46 years (25-63 years) and BMI of 45.0 ± 5.6 kg/m². The follow-up rates at 1 and 18 months were 82.7% and 80.8%. At 18 months, the percentage of weight loss (%TWL) was 33.6 ± 10.4% and the percentage of excess BMI loss (%EBMIL) was 77.6 ± 25%. Postoperatively, a significant increase in accelerated gastric emptying and impaired esophageal body motility occurred at 1 and 18 months. A significant worsening of all the values obtained at both 1 and 18 months postoperatively becomes evident when comparing the results of the APM. After surgery, 76.4% of patients had developed "de novo" GERD at 1 month and 41% at 18 months. No improvement was found in patients with symptomatic GERD.

CONCLUSION

Based on the results of this study, LSG led to a considerable rate of postoperative "de novo" GERD. In addition, no improvement was found in patients with symptomatic GERD.

Secondary Hyperparathyroidism Before and After Bariatric Surgery: a Prospective Study with 2-Year Follow-Up

PURPOSE

Secondary hyperparathyroidism (SHPT) is linked to obesity. Bariatric surgery may be associated with calcium and vitamin D deficiencies leading to SHPT. This study aimed to detect the prevalence of SHPT before and after bariatric surgery.

METHODS

This prospective study assessed the prevalence of SHPT after sleeve gastrectomy (SG, n = 38) compared to one-anastomosis gastric bypass (OAGB, n = 86). All patients were followed up for 2 years. Bone mineral density (BMD) was assessed using dual-energy X-ray absorptiometry.

RESULTS

Of the 124 patients, 71 (57.3%) were females, and 53 (42.7%) were males, with a mean age of 37.5 ± 8.8 years. Before surgery, 23 patients (18.5%) suffered from SHPT, and 40 (32.3%) had vitamin D deficiency. The prevalence of SHPT increased to 29.8% after 1 year and 36.3% after 2 years. SHPT was associated with lower levels of vitamin D and calcium and higher reduction of BMD in the hip but not in the spine. After 2 years, SHPT was associated with a significantly lower T-score in the hip. SHPT and vitamin D deficiency were significantly more common in patients subjected to OAGB compared to SG (p = 0.003, and p < 0.001, respectively). There is a strong negative correlation between vitamin D levels and parathormone levels before and after surgery.

CONCLUSION

Prevalence of SHPT is high in obese patients seeking bariatric surgery, especially with lower vitamin D levels. Bariatric surgery increases the prevalence of SHPT up to 2 years. Gastric bypass is associated with a higher risk of developing SHPT compared to SG.

Portomesenteric venous thrombosis in a prophylactically anticoagulated obese patient after laparoscopic sleeve gastrectomy: a case report

Background

Obesity is associated with an increased risk of morbidity and mortality, so weight reduction is important. Bariatric surgery is a well-tolerated approach for reducing body weight, with laparoscopic sleeve gastrectomy commonly performed. An uncommon and potentially fatal sequela of laparoscopic sleeve gastrectomy is portomesenteric vein thrombosis, which may result in severe bowel ischemia.

Case report

A 32-year-old Middle Eastern obese man (body mass index 33) presented to the emergency department with severe, generalized abdominal pain 2 weeks after laparoscopic sleeve gastrectomy. Computed tomography of the abdomen and pelvis revealed extensive acute on chronic portosplenic and superior mesenteric vein thrombosis with associated small bowel ischemia. Laparoscopic exploration was converted to midline laparotomy and an extensive ischemic small bowel resection.

Conclusion

Laparoscopic sleeve gastrectomy carries a risk of both morbidity and mortality. Venous thromboembolism is a well-known risk of bariatric surgery, but portomesenteric vein thrombosis is also a rare but sometimes serious complication. A high index of suspicion for portomesenteric vein thrombosis to prompt early detection is essential in patients who have undergone laparoscopic sleeve gastrectomy to minimize complications and optimize outcomes. Uncertainty still remains around the optimal dose and duration of anticoagulation after laparoscopic sleeve gastrectomy.

Understanding In Vivo Dissolution of Immediate Release (IR) Solid Oral Drug Products Containing Weak Acid BCS Class 2 (BCS Class 2a) Drugs

In vivo drug dissolution kinetics of BCS Class 2a IR solid oral drug products remains largely unknown. An understanding to what extent the solubility influences in vivo dissolution is needed to design appropriate in vitro dissolution methods. In this study, nonsteroidal anti-inflammatory drugs (NSAIDs) are used to investigate the in vivo dissolution of BCS Class 2a drugs based on numerical deconvolution analyses. The PK data were obtained from published literature or drug applications submitted to the FDA. It has been hypothesized that the in vivo drug dissolution rate would likely correlate to the solubility of NSAIDs in the media at gastrointestinal pH. Our findings show a short lag time of absorption (T_lag), comparable to the liquid gastric emptying time and independent of the solubility and formulation. In Vivo drug dissolution of NSAIDs was generally rapid and complete within the regular drug residence time in the small intestine while multi-phase absorption was observed in some subjects for all the NSAIDs. The comparisons of in vivo drug dissolution rate, which was characterized by in vivo dissolution half-life (T_half), indicate that solubility has a minimal impact on in vivo drug dissolution rate for NSAIDs. Gastric emptying regulated by migrating motor complex (MMC) under fasted state most likely governs drug dissolution and absorption of NSAIDs. For BCS Class 2a IR solid oral drug products, large variability of gastric emptying and MMC as well as the strong driving force of intestinal absorption probably outweigh the impact of solubility on drug in vivo dissolution.

Expected Values of Esophageal Transit and Gastric Emptying Scintigraphy Post-uncomplicated Sleeve Gastrectomy

PURPOSE

Sleeve gastrectomy (SG) results in significant anatomical and physiological alterations of the esophagus and stomach, including food tolerance. Currently, there is no consensus on the parameters of abnormal esophageal transit and gastric emptying in this population. We describe standardized esophageal transit and gastric emptying protocols, and define expected values following an uncomplicated SG.

MATERIALS AND METHODS

In 43 asymptomatic post-SG patients with optimal weight loss, a standardized liquid and semi-solid (oatmeal) esophageal transit study, plus a 90-min semi-solid gastric emptying study with dynamic 5-s image acquisition to assess gastroesophageal reflux, was performed. Gastric emptying half-time and retention rate was calculated. Esophageal transit and reflux were graded by visual inspection of images.

RESULTS

Thirty-one female and 12 male patients participated: mean age 49.0±10.7 years, pre-operative BMI 47.6±7.0 kg/m², excess weight loss 58.8±26.0% at median follow-up of 7.4 months. The standardized semi-solid meal and liquid preparations were well tolerated. Delays in esophageal transit of liquid and semi-solid boluses were infrequent (7.0% and 16.3% respectively). Deglutitive reflux of both semi-solids and liquids was common (48.8% and 32.6%). The median semi-solid gastric emptying half-time was 21.0 min. A large proportion of substrate transited into the small bowel on initial image acquisition (median 39.1%). Reflux events during gastric emptying were common (median 5.0 events, 12.7% of image acquisition time).

CONCLUSIONS

Rapid gastric emptying with asymptomatic deglutitive and post-prandial gastroesophageal reflux events are common following SG. We have defined the expected values of standardized esophageal transit and gastric emptying scintigraphy specifically tailored to SG patients.

Gastrointestinal Physiology Before and After Duodenal Switch with Comparisons to Unoperated Lean Controls: Novel Use of the SmartPill Wireless Motility Capsule

Purpose

Bariatric surgery alters gastrointestinal anatomy. In this exploratory study, the SmartPill® wireless motility capsule (WMC) was used to study changes in gastrointestinal physiology following biliopancreatic diversion with duodenal switch (BPD/DS).

Material and Methods

Twenty-eight BPD/DS patients (35 ± 11 years, 50% females, body mass index [BMI] 56 ± 5) were to be examined preoperatively and postoperatively. In addition to transit time, appetite control and gastrointestinal symptoms were studied by patient-scored questionnaires (visual analogue scale and Gastrointestinal Symptom Rating Scale (GSRS)). Data was compared to 41 lean unoperated controls.

Results

About 1.8 years postoperatively, 18 patients (BMI 35.8 ± 8.3) returned for a second WMC test. As expected, small bowel transit time was reduced, from 3.9 ± 1.6 h to 2.8 ± 2.0, p = 0.02, and at both these time points, it was shorter than in lean controls (5.4 ± 1.9 h, p = 0.001). Postoperatively, a trend towards reduced colon and whole gut transit times was seen in BPD/DS-patients, thus approaching those of lean controls. Surprisingly, BPD/DS patients scored higher satiety than controls preoperatively as well as increased hunger and desire to eat postoperatively. Compared to lean, BPD/DS patients reported a higher total GSRS score at both time points (1.2 ± 0.2 vs 1.7 ± 0.6 and 2.3 ± 0.5, p < 0.001). Postoperatively, the scores for diarrhea and indigestion increased.

Conclusions

The novel use of the SmartPill system in BPD/DS patients gave the expected readouts. Although small bowel transit time was further shortened after BPD/DS, whole gut transit time did not differ from controls. Typical gastrointestinal symptoms were reported postoperatively.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-021-05452-4.

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.

Revisional Surgeries of Laparoscopic Sleeve Gastrectomy

Bariatric surgery has become increasingly common due to the worldwide obesity epidemic. A shift from open to laparoscopic surgery, specifically, laparoscopic sleeve gastrectomy (LSG), has occurred in the last two decades because of the low morbidity and mortality rates of LSG. Although LSG is a promising treatment option for patients with morbid obesity due to restrictive and endocrine mechanisms, it requires modifications for a subset of patients because of weight regain and tough complications, such as gastroesophageal reflux, strictures, gastric leak, and persistent metabolic syndrome., Revision surgeries have become more and more indispensable in bariatric surgery, accounting for 7.4% in 2016. Mainstream revisional bariatric surgeries after LSG include Roux-en-Y gastric bypass, repeated sleeve gastrectomy, biliopancreatic diversion, duodenal switch, duodenal-jejunal bypass, one-anastomosis gastric bypass, single anastomosis duodeno-ileal bypass (SAID) and transit bipartition. This review mainly describes the revisional surgeries of LSG, including the indication, choice of surgical method, and subsequent effect.

Continuous glucose monitoring in patients with remission of type 2 diabetes after laparoscopic sleeve gastrectomy without or with duodenojejunal bypass

Bariatric surgery is associated with a high remission rate of type 2 diabetes mellitus. However, it is unclear whether patients showing remission of diabetes actually have normal blood glucose levels throughout the day. We therefore performed continuous glucose monitoring (CGM) in 15 ambulatory patients showing remission of diabetes after laparoscopic sleeve gastrectomy (LSG) without or with duodenojejunal bypass (DJB) at the time of diabetic remission (12.9 ± 1.8 months after bariatric surgery). The definition of remission of diabetes was based on the American Diabetes Association criteria. The mean, SD, and coefficient of variation (CV) of glucose calculated from CGM were 6.2 ± 0.6 mmol/L, 1.5 ± 0.4 mmol/L, and 23.7 ± 6.2%, respectively. These values were higher than those of healthy participants without diabetes previously reported. The percentages of time spent above 10.0 mmol/L and below 3.9 mmol/L were 2.6 (IQR 0-5.0)% and 0 (IQR 0-8.0)%, respectively. Thus, patients with remission of diabetes after LSG or LSG/DJB still had substantial periods of hyperglycemia and hypoglycemia throughout the day. Therefore, we must manage patients with diabetes carefully, even after apparent remission of type 2 diabetes in response to bariatric surgery.

Risk of anemia in morbidly obese patients after bariatric surgery in Taiwan

BACKGROUND

Bariatric surgery is one of most effective long-term treatments for morbid obesity. However, post-bariatric surgery anemia is identified as a common adverse effect and remains a challenge nowadays.

AIM

To estimate the risk of post-bariatric surgery anemia and to stratify the association between age, gender, and types of surgery.

METHODS

This study is a population-based cohort study. We conducted this nationwide study using claims data from National Health Insurance Research Database in Taiwan. There were 4373 morbidly obese patients in this study cohort.

RESULTS

Among patients who were diagnosed with morbid obesity, 2864 received bariatric surgery. All obesity-associated comorbidities decreased in the surgical group. Increasing risk of post-bariatric surgery anemia among obese patients was found by Cox proportional hazards regression [adjusted hazard ratio (HR): 2.36]. Also, we found significantly increasing cumulative incidence rate of anemia among patients receiving bariatric surgery by log-rank test. After adjusting for age and gender, the increasing incidence of post-bariatric surgery anemia was found among women (adjusted HR: 2.48), patients in the 20–29-year-old group (adjusted HR: 3.83), and patients in the 30-64-year-old group (adjusted HR: 2.37). Moreover, malabsorptive and restrictive procedures had significantly higher adjusted HRs, 3.18 and 1.55, respectively.

CONCLUSION

Bariatric surgery give rise to anemia risk among obese patients, specifically in women, young- and middle-aged patients, and patients undergoing malabsorptive procedures in our population-based cohort study in Taiwan.

Geometry of Sleeve Gastrectomy Measured by 3D CT Versus Weight Loss: Preliminary Analysis

BACKGROUND

The size of the remnant stomach with respect to weight loss failure after laparoscopic sleeve gastrectomy (LSG) remains controversial. This study aimed to evaluate the impact of the actual size and volume of the remnant stomach, as measured by three-dimensional computed tomography (3D-CT) volumetry, on weight loss after LSG.

METHODS

The clinical outcomes of 52 patients who underwent LSG between October 2008 and February 2019 were assessed. Weight metrics were recorded at 1, 3, and 6 months and 1 year postoperatively. 3D-CT volumetry was performed 1 year postoperatively, and the total remnant stomach volume (TSV), proximal stomach volume (PSV), antral stomach volume (ASV), and the distance between the pylorus and the distal edge of staple line (DPS) were measured. The relationship between the weight metrics and aforementioned factors was analyzed.

RESULTS

Of the 52 patients who underwent LSG, 40 patients participated in this study. The average body mass index preoperatively was 38.3 ± 5.1 kg/m², and the average percentage of total weight loss (%TWL) 1 year after LSG was 26.6 ± 9.3%. The average TSV, PSV, ASV, and DPS were 123.2 ± 60.3 ml, 73.4 ± 37.2 ml, 49.8 ± 30.3 ml, and 59.9 ± 18.5 mm, respectively. The DPS (r = - 0.394, p = 0.012) and ASV (r = - 0.356, p = 0.024) were correlated with %TWL 1 year postoperatively.

CONCLUSIONS

The actual DPS and ASV measured by 3D-CT affected weight loss after LSG. 3D-CT may be useful for the immediate identification of factors affecting insufficient weight loss in patients; this may, in turn, aid in the implementation of early intervention treatments.

Thyroid Hormone Changes After Sleeve Gastrectomy With and Without Antral Preservation

BACKGROUND

The effect of bariatric surgery on thyroid hormone changes yielded inconsistent results. The aim of the present study was to assess the change of thyroid hormone levels following laparoscopic sleeve gastrectomy (LSG), with or without antral preservation (AP).

METHODS

Thyroid hormones (TSH, FT3, FT4) were examined preoperatively, at the end of the first postoperative month, and first postoperative year. Secondly, antral resection (AR) and AP were compared at inducing weight loss and thereby affecting thyroid hormone levels.

RESULTS

Euthyroid obese patients (86 female/20 male) underwent LSG. Of these, 58 patients underwent AR and 48 patients AP. The mean FT3 levels significantly decreased both in the first postoperative month and the first year (P < 0.001), whereas mean TSH levels decreased significantly in the first postoperative year (P < 0.001). FT4 levels remained nearly unchanged (P = 0.517). Postoperative first year body mass index (BMI) loss, excess BMI loss percentile (%EBMIL), and total body weight loss percentile (%TWL) were significantly higher in AR group than the AP group (P ≤ 0.01). When the change in thyroid hormone levels was analyzed by pyloric distance according to time periods, no significant difference was found in TSH and FT4 levels (P > 0.05); however, reduction in FT3 levels was significantly greater in patients with AR than in AP patients (P = 0.028).

CONCLUSION

LSG promotes significant reduction in TSH and FT3 levels, whereas FT4 levels remain unchanged. LSG with AR provides more weight loss in short term and appears to be more effective at lowering FT3 levels.

Relation of Gastric Volume With Weight Loss After Sleeve Gastrectomy: Results of a Prospective Analysis

BACKGROUND

Postoperative sleeve volume (SV) is a key factor in evaluating the results of laparoscopic sleeve gastrectomy (LSG). An objective measurement of SV was obtained with 3-dimensional computed tomographic (3DCT) reconstruction. Several studies have compared SV with percent excess weight loss (%EWL), identifying an inverse relationship. We hypothesized that gastric capacity is one of the factors responsible for weight loss after LSG.

OBJECTIVES

Outcomes of the study were the analysis of the inverse correlation between SV and weight loss (%EWL and body mass index) at the 12-month follow-up, and evaluation of SV in the group with %EWL >50%. In addition, the failure rate was quantified in the SV >180 mL group.

MATERIALS AND METHODS

This is a prospective study with the collection of data. All patients who received LSG from January to December 2017 were evaluated. Computed tomography was performed on the upper abdomen at 12 months postoperatively to measure the SV using a standardized technique involving gastric distension.

RESULTS

A total of 42 patients were considered for 3DCT evaluation at the 12-month follow-up. A significant linear inverse relation was reported between SV and %EWL (P<0.05); a similar trend, without significant results, was reported for body mass index loss. The entire cohort was subdivided according to %EWL. A %EWL<50% presented a significantly higher mean SV (P<0.01) than %EWL >50%. SV >180 mL was powerful in predicting abnormal gastric distension. Over this value, %EWL was lower than that in the remaining group (P<0.05, 31.9% vs. 51.8%).

CONCLUSIONS

Our results confirmed a direct relation between SV and %EWL. Objective evaluation of gastric compliance obtained with 3DCT should be used intensively for LSG.

Prospective study of gut hormone and metabolic changes after laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass

Background

Laparoscopic sleeve gastrectomy (SG) has surpassed Roux-en-Y gastric bypass (RYGB) as the most prevalent bariatric procedure worldwide. While RYGB and SG demonstrate equivalent short-term weight loss, long-term weight loss tends to be greater after RYGB. Differences in the effect of these procedures on gastrointestinal hormones that regulate energy homeostasis are felt to partially underlie differences in outcomes. The objective of this study was to prospectively quantify blood levels of gut hormones of energy and glucose homeostasis at one year follow up to delineate possible reasons for greater efficacy of RYGB over SG in achieving weight loss.

Methods

Patients undergoing SG (n = 19) and RYGB (n = 40) were studied before surgery and at 2,12, 26, and 52 weeks postoperatively. Blood samples drawn in the fasted state and after a liquid mixed meal were assayed at baseline, 26, and 52 weeks for peptide YY (PYY), glucagon-like peptide-1 (GLP-1), ghrelin, insulin, glucose, and leptin. Fasting and postprandial appetitive sensations were assessed by visual analog scale.

Results

At 1 year there was greater weight loss in RYGB compared with SG patients (30% vs 27%; P = 0.03). Area under the curve (AUC) after the mixed meal for PYY was greater in RYGB patients (P<0.001). RYGB patients had significant increases in GLP-1 AUC compared to baseline (P = 0.002). Ghrelin levels decreased only after SG compared to baseline (P<0.001) but were not significantly different from RYGB. There was a trend toward decreased sweet cravings in RYGB patients (P = 0.056).

Conclusions

Differences in gastrointestinal hormones that regulate energy and glucose homeostasis are a possible mechanism for greater efficacy of RYGB compared to SG.

Effects of Laparoscopic Sleeve Gastrectomy on Gastric Structure and Function Documented by Magnetic Resonance Imaging Are Strongly Associated with Post-operative Weight Loss and Quality of Life: a Prospective Study

BACKGROUND

This prospective study applied magnetic resonance imaging (MRI) to assess the effect of laparoscopic sleeve gastrectomy (LSG) on gastric structure and function. The impact of these changes on patient outcomes was analyzed.

METHOD

Obese patients without gastrointestinal symptoms referred for bariatric surgery were recruited prospectively. Pre-operative assessment included (i) high-resolution manometry and pH-impedance monitoring and (ii) magnetic resonance imaging (MRI) measurement of gastric capacity, accommodation, and emptying with the 400 ml liquid Nottingham test meal (NTM). Studies were repeated 6-7 months after LSG. Weight loss and changes in the Gastrointestinal Quality of Life Index (GIQLI) assessed patient outcomes.

RESULTS

From 35 patients screened, 23 (66%) completed the study (17 females, age 36 ± 10 years, BMI 42 ± 5 kg/m2). Mean excess weight loss was 59 ± 18% at follow-up. Total gastric volume (capacity) after the meal was 467 mL (455-585 ml) before and 139 mL (121-185 ml) after LSG (normal reference 534 (419-675) mL), representing a mean 70% reduction (p < 0.0001). Similar findings were present for gastric content volume indicating rapid early-phase gastric emptying (GE) post-LSG. Conversely, late-phase GE was slower post-LSG (2.5 ± 1.0 vs. 1.4 ± 0.6 mL/min; p < 0.0001; (reference 1.5(1.4-4.9) mL/min)). Patients with ≥ 80% reduction in gastric capacity had greater weight loss (p = 0.008), but worse gastrointestinal outcomes (p = 0.023).

CONCLUSIONS

MRI studies quantified the marked reduction in gastric capacity after LSG. The reduction in capacity was associated with rapid early- but slow late-phase GE after surgery. These changes were associated with weight loss; however, reductions in gastric capacity ≥ 80% were linked to increased acid reflux and impacted on gastrointestinal quality of life.

Revisiting the Ghrelin Changes Following Bariatric and Metabolic Surgery

Since the description of ghrelin in 1999, several studies have dug into the effects of this hormone and its relationship with bariatric surgery. While some aspects are still unresolved, a clear connection between ghrelin and the changes after metabolic surgery have been established. Besides weight loss, a significant amelioration in obesity-related comorbidities following surgery has also been reported. These changes in patients occur in the early postoperative period, before the weight loss appears, so that amelioration may be mainly due to hormonal changes. The purpose of this review is to go through the current body of knowledge of ghrelin's physiology, as well as to update and clarify the changes that take place in ghrelin concentrations following bariatric/metabolic surgery together with their potential consolidation to outcomes.

Laparoscopic Sleeve Gastrectomy with T-Shaped Omentoplasty: Impact on the Early Postoperative Outcomes

PURPOSE

Laparoscopic sleeve gastrectomy (LSG) is an effective bariatric procedure, yet can be followed by complications such as staple line leak and bleeding, vomiting, and gastroesophageal reflux disease (GERD). Various attempts have been described in the literature to improve the early outcome of LSG through various measures. This study aimed to assess the impact of adding T-shaped omentoplasty to LSG on the short-term outcome of the procedure.

METHODS

This was a retrospective cohort study on patients with morbid obesity who underwent LSG in the period of November 2015 to November 2018. The outcome of patients with morbid obesity who underwent LSG combined with T-shaped omentoplasty (group I) was compared with that of a similar number of patients who underwent classical LSG without staple line fixation (group II). The main outcome measures were the rates of staple line bleeding and leak, postoperative nausea and vomiting (PONV), GERD, gastric axial rotation, other complications, and weight loss.

RESULTS

The study included 106 patients of a mean BMI of 49.8 kg/m². Group II had significantly higher PONV) scale at 1 week and 1 month than group I. Group I had significantly lower rates of staple line bleeding (0 vs 9.6%, p = 0.02) and GERD (3.7% vs 17.3%, p = 0.02) than group II. Both groups had similar rates of staple line leak and comparable operation time.

CONCLUSION

Staple line fixation using the T-shaped omentoplasty technique was associated with lower incidence of significant PONV, staple line bleeding, and GERD as compared with classical LSG.

The hundred most frequently cited studies on sleeve gastrectomy

INTRODUCTION

Sleeve gastrectomy (SG) is one of the most popular bariatric operations and one of the most frequently studied areas in bariatric surgery.

AIM

To summarise the characteristics of the most frequently cited studies focusing on SG.

MATERIAL AND METHODS

We used the Web of Science database to identify all studies focused on SG published from 2000 to 2018. The term "sleeve gastrectomy" and synonyms were used to reveal the 100 most cited records.

RESULTS

The most frequently cited publication had 493 citations. The highest mean number of citations per year was 73.00. Studies were most frequently published in the years 2010 and 2012. Articles were most commonly published in bariatric surgery-oriented journals.

CONCLUSIONS

Our study indicates an increase in medical researchers' interest in the subject of SG and underlines the need to perform studies with a higher level of evidence to further analyse the outcomes and basic science behind SG.

Sleeve gastrectomy enhances glucose utilization and remodels adipose tissue independent of weight loss

Sleeve gastrectomy (SG) induces weight loss-independent improvements in glucose homeostasis by unknown mechanisms. We sought to identify the metabolic adaptations responsible for these improvements. Nonobese C57BL/6J mice on standard chow underwent SG or sham surgery. Functional testing and indirect calorimetry were used to capture metabolic phenotypes. Tissue-specific glucose uptake was assessed by 18-fluorodeoxyglucose (18-FDG) PET/computed tomography, and RNA sequencing was used for gene-expression analysis. In this model, SG induced durable improvements in glucose tolerance in the absence of changes in weight, body composition, or food intake. Indirect calorimetry revealed that SG increased the average respiratory exchange ratio toward 1.0, indicating a weight-independent, systemic shift to carbohydrate utilization. Following SG, orally administered 18-FDG preferentially localized to white adipose depots, showing tissue-specific increases in glucose utilization induced by surgery. Transcriptional analysis with RNA sequencing demonstrated that increased glucose uptake in the visceral adipose tissue was associated with upregulation in transcriptional pathways involved in energy metabolism, adipocyte maturation, and adaptive and innate immune cell chemotaxis and differentiation. SG induces a rapid, weight loss-independent shift toward glucose utilization and transcriptional remodeling of metabolic and immune pathways in visceral adipose tissue. Continued study of this early post-SG physiology may lead to a better understanding of the anti-diabetic mechanisms of bariatric surgery.

Prevalence of Dumping Syndrome After Laparoscopic Sleeve Gastrectomy and Comparison with Laparoscopic Roux-en-Y Gastric Bypass

BACKGROUND

Dumping syndrome is a well-known side effect of laparoscopic gastric bypass (LRYGB), and it is commonly believed that dumping syndrome is less likely to occur after laparoscopic sleeve gastrectomy (LSG), due to the preservation of the pyloric sphincter. However, it is not uncommon for patients undergoing LSG at our center to report symptoms suggestive of dumping syndrome.

OBJECTIVE

To assess the prevalence of symptoms of dumping syndrome after LSG compared with LRYGB.

SETTING

A single surgical group at a high-volume (700 cases per year) Bariatric and Metabolic Surgery Center of Excellence.

METHODS

One thousand four hundred seventy-one LRYGB (366) and LSG (1105) patients received a questionnaire to assess symptoms of dumping syndrome, utilizing a modified version of the Sigstad scoring system. Dumping syndrome was considered to be present when the questionnaire score exceeded a threshold value.

RESULTS

A total of 360 responses were received (249 LSG, 111 LRYGB). 26.5% (66) LSG and 41.4% (46) LRYGB exceeded the threshold for dumping syndrome (p < 0.01). 84.8% (56) LSG and 84.7% (39) LRYGB reported early dumping syndrome (p > 0.05). Thirty-six percent (24) LSG and 28% (13) LRYGB reported late dumping syndrome (p > 0.05). Twenty-seven percent (62) LSG and 44.4% (44) LRYGB reported at least one symptom of dumping syndrome with sweets (p < 0.05). 34.3% (85) LSG and 35.5% (39) LRYGB reported symptoms when drinking with or within 30 min of a meal (p > 0.05). 14.5% (36) LSG and 17.3% (19) LRYGB reported symptoms after alcohol consumption (p > 0.05).

CONCLUSION

Dumping syndrome after LSG is prevalent but has not been widely reported. This finding may impact clinicians and patients in their choice of procedure and has relevance in post-operative education and care.

Dietary daidzein decreases food intake accompanied with delayed gastric emptying in ovariectomized rats

We previously found that equol, a metabolite of intestinal bacterial conversion from soy isoflavone daidzein, has female-specific anorectic effects. In the present study, we used seven-week-old female ovariectomized (OVX) Sprague Dawley rats to test the hypothesis that the anorectic effect of dietary daidzein may be attributed to delayed gastric emptying. Results suggest that dietary daidzein delays gastric emptying and that it has an anorectic effect with residual gastric contents, but not without gastric contents. Dietary equol significantly decreased daily food intake in the OVX rats without sleeve gastrectomy, but not in those with sleeve gastrectomy, suggesting that the accumulation of food in the stomach is required for the anorectic effect of equol to occur. These results support the hypothesis that the anorectic effect of dietary daidzein is attributed to delayed gastric emptying.

Prospective study of the changes in pharmacokinetics of immunosuppressive medications after laparoscopic sleeve gastrectomy

Laparoscopic sleeve gastrectomy induces weight loss via the creation of a restrictive gastric tube for early satiety and is associated with an accelerated gastric transit time. A prospective, single-dose pharmacokinetic study was performed, prior to and after laparoscopic sleeve gastrectomy, for tacrolimus, extended-release tacrolimus, mycophenolate mofetil, and enteric-coated mycophenolate sodium. The study included 12 morbidly obese patients in chronic renal failure. The median decrease in body mass index was 8.8 kg/m² with an excess body weight loss of 54.9%. The AUC₂₄ of all drugs were increased after laparoscopic sleeve gastrectomy by 46%, 55%, 77%, and 74%, respectively. The maximum concentrations were increased for tacrolimus, extended-release tacrolimus, and mycophenolate mofetil by 43%, 46%, and 65%. The apparent total clearances were decreased for tacrolimus, mycophenolate mofetil, and enteric-coated mycophenolate sodium by 36%, 57%, and 38%. Laparoscopic sleeve gastrectomy can be associated with significant changes in pharmacokinetics of the drugs evaluated. The mechanism is likely decreased apparent drug clearance due to an increased drug exposure (from a more distal site of intestinal absorption with decreased intestinal metabolism), or decreased clearance (liver metabolism). Adapting the monitoring of immunosuppression will be important to avoid overdosing and potential side effects.

Complications of bariatric surgery in adolescents

Over the past decade, outcomes data have demonstrated the benefit of bariatric surgery in achieving both sustained weight loss and reversal of co-morbidities. Comparing these data to contemporary known risks of adolescent bariatric surgery informs the patients and providers considering bariatric procedures and provides insight into potential ways to reduce and manage complications. The goal of this article is to review the common surgical and postoperative complications following bariatric procedures and discuss approaches to improve their safety. A systematic review identifying bariatric surgery complications in adolescents was conducted. The review focused on the data relevant to adolescent bariatric surgery. However, when necessary, adult studies were used to address the gaps in available pediatric information. The data pertaining to the intraoperative, short term, and long term surgically related and nutritional related complications show that complication are declining with increasing experience. Specific recommendations and strategies to avoid major complications of bariatric surgery in adolescents are offered.

Metabolic effects and outcomes of sleeve gastrectomy and gastric bypass: a cohort study

BACKGROUND

The outcomes of bariatric surgery should not be evaluated only for weight loss purposes but from a wider point of view that is closer to the reality of morbidly obese patients. The study of the influence of bariatric surgery over obesity-related diseases in bariatric patients is worthwhile.

METHODS

We present a cohort study of 329 patients who underwent either laparoscopic sleeve gastrectomy (LSG: 165 patients) or laparoscopic gastric bypass (LRYGBP: 164). We analyzed complication rate, comorbidities and weight loss evolution.

RESULTS

Both groups were comparable in demographic characteristics at baseline. Significant statistical differences were found in length of hospital stay and operative time (both were lower in the LSG group). Bleeding and wound infection were higher in the LRYGBP group, as it happened with intestinal occlusion as a late complication (p < 0.05). After a 5-year follow-up, the percentage of excess weight loss (%EWL) was higher in gastric bypass than sleeve gastrectomy (p = 0.01) but there was no statistical difference in percentage of total weight loss (%TWL) (p = 0.2). The resolution of comorbidities was similar in both groups except for dyslipidemia, which resolution was significantly higher in the gastric bypass group (p = 0.005). Metabolic syndrome (MeTS) resolution was similar in both groups.

CONCLUSIONS

Sleeve gastrectomy and gastric bypass achieve similar outcomes in hypertension, type 2 diabetes, obstructive sleep apnea and MeTS resolution even when there is weight regain. Although gastric bypass achieves higher weight loss in morbid obese patients, complication rates are also higher compared to those of sleeve gastrectomy. Thus, the appropriate procedure should be tailored based on patient factors and comorbidities, but also on surgeon comfort level and experience.