Managing medical and surgical disorders after divided Roux-en-Y gastric bypass surgery

Surgical Intervention Could Relieve Obstruction-Related Symptoms of Refractory Superior Mesenteric Artery Syndrome: Long-Term Follow-up Results

PURPOSE

Superior mesenteric artery syndrome (SMAS) is one of the rare causes of chronic duodenal obstruction. The aim of our study was to evaluate the outcomes of surgical management of refractory SMAS (Re-SMAS) in our institution during the last decade.

MATERIALS AND METHODS

Consecutive patients diagnosed as Re-SMAS and underwent surgical intervention were retrospectively enrolled. A modified Likert-scale-based questionnaire was used to quantify the symptoms of SMAS. The primary outcome was the increase of BMI and symptomatic relief after surgery.

RESULTS

From January 2010 to January 2020, 22 patients diagnosed with Re-SMAS and underwent surgery were included. Age distribution of included patients were < 19 (10/22, 45%), 19-45 (11/22, 50%), and > 45 (1/22, 5%). A significant BMI increase was recorded, [16.1 (14.6-23.7) kg/m² vs 21.9 (15.6-29.5) kg/m² before and after surgery, respectively, p < 0.001]. Up to 20 patients (20/22, 91%) reported symptomatic relief. The obstruction-related symptom score decreasing significantly (p < 0.001), with reported nausea, vomiting, and regurgitation incidences dropping from 77 to 41% (p = 0.031), 68 to 23% (p = 0.006), and 32 to 5% (p = 0.046), respectively.

CONCLUSION

Surgical interventions could relieve obstruction-related symptoms of Re-SMAS and promote weight gain. For patients who suffered from Re-SMAS and referred to surgeons mainly for obstruction-related symptoms, surgical intervention is recommended.

Rates, Risks, and Time to Fracture in Patients Undergoing Laparoscopic Vertical Sleeve Gastrectomy versus Roux-en-Y Gastric Bypass

Objective

To assess the rates, risks, and time to fracture in patients undergoing laparoscopic vertical sleeve gastrectomy (VSG) versus those undergoing Roux-en-Y gastric bypass (RYGB).

Summary Background Data

Metabolic and bariatric surgery has been implicated in significant bone loss and may increase fracture risk. Preoperative patient characteristics that might impact fracture risk and the time to fractures have not been established. Furthermore, the patient characteristics that might impact fracture risk and the time to fractures by surgical approach are unknown.

Methods

This population-based retrospective cohort analysis used Humana claims data from January 1, 2007 to March 31, 2017, and included 4073 patients undergoing laparoscopic RYGB and VSG as a first surgical intervention for weight loss. The primary outcomes were the incidence of fractures (Humeral, Radial or Ulnar, Pelvic, Hip, and Vertebral) within 48 months after laparoscopic VSG versus RYGB and days to these fractures.

Results

An analysis of total fractures (odds ratio [OR] 0.53; 95% confidence interval [CI], 0.38-0.73), vertebral fractures (OR 0.61; 95% CI, 0.38-0.99), hip fractures (OR 0.36; 95% CI, 0.15-0.84), and humeral fractures (OR 0.44; 95% CI, 0.22-0.90) demonstrated a reduction in fracture risk in patients undergoing VSG versus RYGB. Furthermore, postmenopausal status was independently associated with increased odds of total fractures and hip fractures (OR 2.18; 95% CI, 1.06-4.50; OR 5.83; 95% CI, 1.16-29.27; respectively). Likewise, osteoporosis at the time of surgery was associated with increased odds of total fractures (OR 1.61; 95% CI, 1.09-2.37), vertebral fractures (OR 2.01; 95% CI, 1.19-3.39), and hip fractures (OR 2.38; 95% CI, 1.19-4.77). Except for a significantly decreased odds of vertebral fractures in osteoporotic patients undergoing VSG versus RYGB (OR 0.41; 95% CI, 0.18-0.95), osteoporotic or postmenopausal status at the time of surgery was not found to increase odds of fracture depending on surgical intervention. However, time to fracture (total) and for all site-specific fractures, except for pelvic fractures, was significantly reduced in postmenopausal women undergoing RYGB versus VSG. Time to fracture (total) and for all site-specific fractures except pelvic and radial or ulnar fractures was significantly reduced in osteoporotic patients undergoing RYGB versus VSG.

Conclusions and Relevance

Though bariatric surgery is associated with several health-related benefits, increased fracture risk is an important factor to discuss with patients undergoing bariatric surgery. Bariatric surgery strategy, RYGB versus VSG, carries a differential risk of fracture, with RYGB carrying a higher risk of fracture and decreased time to fracture. Furthermore, patients who are postmenopausal or osteoporotic at the time of surgery carry an increased risk of total fractures, independent of bariatric surgery strategy. Being mindful of patient-specific fracture risk after bariatric surgery may help anticipate, identify, and prevent fractures.

Progress in treatment of type 2 diabetes by bariatric surgery

The incidence of type 2 diabetes (T2D) is increasing at an alarming rate worldwide. Bariatric surgical procedures, such as the vertical sleeve gastrectomy and Roux-en-Y gastric bypass, are the most efficient approaches to obtain substantial and durable remission of T2D. The benefits of bariatric surgery are realized through the consequent increased satiety and alterations in gastrointestinal hormones, bile acids, and the intestinal microbiota. A comprehensive understanding of the mechanisms by which various bariatric surgical procedures exert their benefits on T2D could contribute to the design of better non-surgical treatments for T2D. In this review, we describe the classification and evolution of bariatric surgery and explore the multiple mechanisms underlying the effect of bariatric surgery on insulin resistance. Based upon our summarization of the current knowledge on the underlying mechanisms, we speculate that the gut might act as a new target for improving T2D. Our ultimate goal with this review is to provide a better understanding of T2D pathophysiology in order to support development of T2D treatments that are less invasive and more scalable.

Haemoglobin and Hematinic Status Before and After Bariatric Surgery over 4 years of Follow-Up

PURPOSE

Bariatric surgery is associated with deficiencies of vitamins and minerals, and patients are routinely advised supplements postoperatively. We studied prevalence of vitamin B12, folate and iron deficiencies and anaemia before and after bariatric surgery over 4 years of follow-up.

MATERIALS AND METHODS

We performed a retrospective cohort analysis of 353 people with obesity, including 257 (72.8%) women, who underwent gastric bypass (252, 71.4%) or sleeve gastrectomy (101, 28.6%) at our National Health Service bariatric centre in Northwest England.

RESULTS

At baseline, mean (standard error) age was 46.0 (0.6) years, body mass index 53.1 (0.4) kg/m2, serum vitamin B12 400.2 (16.4) pg/L, folate 7.7 (0.2) μg/L, iron 12.0 (0.3) μmol/L, ferritin 118.3 (8.4) μg/L and haemoglobin 137.9 (0.8) g/L. Frequency of low vitamin B12 levels reduced from 7.5% preoperatively to 2.3% at 48 months (P < 0.038). Mean folate levels increased from baseline to 48 months by 5.3 μg/L (P < 0.001) but frequency of low folate levels increased from 4.7% preoperatively to 10.3% (P < 0.048). Ferritin levels increased from baseline to 48 months by 51.3 μg/L (P < 0.009). Frequency of low ferritin levels was greater in women (39.1%) than in men (8.9%) at baseline (P < 0.001) and throughout the study period. Haemoglobin was low in 4.6% of all patients at baseline with no significant change over the study period.

CONCLUSION

There were notable rates of haematinic insufficiencies in bariatric surgical candidates preoperatively. Our study lends further support to regular supplementation with vitamin B12, folic acid, and iron in people undergoing bariatric surgery.

Laparoscopic Vertical Sleeve Gastrectomy as a Treatment Option for Adults with Diabetes Mellitus

Obesity is a major factor in the worldwide rise in the prevalence of type 2 diabetes mellitus. The obesity "epidemic" will require novel, effective interventions to permit both the prevention and treatment of diabetes caused by obesity. Laparoscopic vertical sleeve gastrectomy is a newer bariatric surgical procedure with a lower risk of complications (compared to Roux-en-Y gastric bypass surgery). Based in part on restriction of daily caloric intake, sleeve gastrectomy has a major role in inducing significant weight loss and weight loss is maintained for at least 10 years. Prior studies have supported the utility of the vertical sleeve gastrectomy for the treatment and management of subgroups of individuals with diabetes mellitus. There are reports of 11% to 76.9% of obese individuals discontinuing use of diabetic medications in studies lasting up to 8 years after vertical sleeve gastrectomy. Major ongoing issues include the preoperative determination of the suitability of diabetic patients to undergo this bariatric surgical procedure. Understanding how this surgical procedure is performed and the resulting anatomy is important when vertical sleeve gastrectomy is being considered as a treatment option for diabetes. In the postoperative periods, specific macronutrient goals and micronutrient supplements are important for successful and safer clinical results. An understanding of immediate- and long term- potential complications is important for reducing the potential risks of vertical sleeve gastrectomy. This includes the recognition and treatment of postoperative nutritional deficiencies and disorders. Vertical sleeve gastrectomy is a component of a long term, organized program directed at treating diabetes related to obesity. This approach may result in improved patient outcomes when vertical sleeve gastrectomy is performed to treat type 2 diabetes in obese individuals.

Fractures in Adults After Weight Loss from Bariatric Surgery and Weight Management Programs for Obesity: Systematic Review and Meta-analysis

BACKGROUND

Weight loss interventions for obesity, such as bariatric surgery, are associated with reductions in bone mineral density and may increase the risk of fractures. We undertook a systematic review and meta-analysis of bariatric surgery and lifestyle weight management programs (WMPs) with fracture outcomes.

METHODS

We searched MEDLINE, Embase, the Cochrane Central Register of Controlled Trials from 1966 to 2018, and our trial registry of WMP randomized controlled trials (RCTs). We included RCTs, non-randomized trials, and observational studies of bariatric surgery, and RCTs of WMPs. Studies had follow-up ≥ 12 months, mean group body mass index ≥ 30 kg/m². The primary outcome measure was incidence of any type of fracture in participants, and the secondary outcome was weight change. We used random effects meta-analysis for trial data.

RESULTS

Fifteen studies were included. Three small trials provided short-term evidence of the association between bariatric surgery and participants with any fracture (365 participants; RR 0.82; 95% CI 0.29 to 2.35). Four out of six observational studies of bariatric surgery demonstrated significantly increased fracture risk. Six RCTs of WMPs with 6214 participants, the longest follow-up 11.3 years, showed no clear effect on any type of fracture (RR 1.04; 95% CI 0.91 to 1.18), although authors of the largest RCT reported an increased risk of frailty fracture by their definition (RR 1.40; 95% CI 1.04 to 1.90).

CONCLUSION

Bariatric surgery appears to increase the risk of any fracture; however, longer-term trial data are needed. The effect of lifestyle WMPs on the risk of any fracture is currently unclear.

Oral copper absorption in men with morbid obesity

Copper deficiency has been reported in patients with severe obesity, both before and after bariatric surgery, the latter at increased rates. However, little is known about the absorption of copper. Because of differences in copper dynamics between men and women in the limited available data, we evaluated copper absorption in men who were candidates for bariatric surgery. All patients gave informed consent, approved by the University of Pennsylvania Institutional Review Board, to participate in a pharmacokinetics study. After a 12-h fast, body composition was measured using air displacement plethysmography and a single oral dose of 4mg copper gluconate was given followed by serial measures of serum copper over 10h. Meals and snacks very low in copper were provided. The seven participants had age 52±8years, BMI 44.87±9.01kg/m² and fat free mass 77.92±14.45kg. Baseline serum copper was 36.1±19.5μg/dL and ceruloplasmin was 50.86±4.58mg/dL. Peak copper absorption occurred within 1-2h. The AUC for six subjects was 254.6±151.3μg/100mLh. The estimated volume of distribution (1.98±0.36L) was ∼25mL/kg fat free mass. In these severely obese men, copper absorption occurred early in spite of their normal copper status, suggesting no impairment of absorption due to obesity. Further studies of copper absorption after the significant weight loss and possible malabsorption derived from bariatric surgery are needed.

Predictors of Vitamin Adherence After Bariatric Surgery

BACKGROUND

Vitamin supplementation in bariatric aftercare is essential to prevent nutrient deficiencies; however, rates of vitamin adherence have been as low as 30 % 6 months post-surgery. Preliminary literature suggests non-adherence to prescribed treatments can be linked to demographic and psychological factors. We aimed to determine the relationship between these factors to vitamin adherence in post-bariatric surgery patients.

METHODS

A total of 92 bariatric patients were assessed 6 months post-surgery. Patients were administered a questionnaire collecting demographic information, psychological scores, and self-reported adherence. Nutrient deficiencies were analyzed through serum vitamin levels measured 3 and 6 months after surgery. Wilcoxon rank-sum and chi-square tests were used for analysis.

RESULTS

Non-adherence was associated with male sex and full-time employment (p = 0.027, p = 0.015). There were no differences with respect to living situation, education level, or relationship type. Non-adherent patients did not have significantly higher scores for generalized anxiety, depressive symptoms, or avoidant behaviors. However, non-adherent patients displayed greater attachment anxiety than their adherent counterparts (p = 0.0186). Non-adherence was also associated with lower vitamin B12 levels 6 months post-surgery (p = 0.001).

CONCLUSIONS

Male gender and full-time work have previously been shown to be associated with non-adherence. This is the first study to demonstrate that attachment anxiety is associated with poor multivitamin adherence in the post-surgical bariatric population. This result is concordant with recent literature that has demonstrated attachment anxiety is associated with poor adherence to dietary recommendations in bariatric patients 6 months postoperatively. Presurgical screening for attachment anxiety could facilitate early interventions to promote better bariatric aftercare in this group.

Organization of future training in bariatric gastroenterology

A world-wide rise in the prevalence of obesity continues. This rise increases the occurrence of, risks of, and costs of treating obesity-related medical conditions. Diet and activity programs are largely inadequate for the long-term treatment of medically-complicated obesity. Physicians who deliver gastrointestinal care after completing traditional training programs, including gastroenterologists and general surgeons, are not uniformly trained in or familiar with available bariatric care. It is certain that gastrointestinal physicians will incorporate new endoscopic methods into their practice for the treatment of individuals with medically-complicated obesity, although the long-term impact of these endoscopic techniques remains under investigation. It is presently unclear whether gastrointestinal physicians will be able to provide or coordinate important allied services in bariatric surgery, endocrinology, nutrition, psychological evaluation and support, and social work. Obtaining longitudinal results examining the effectiveness of this ad hoc approach will likely be difficult, based on prior experience with other endoscopic measures, such as the adenoma detection rates from screening colonoscopy. As a long-term approach, development of a specific curriculum incorporating one year of subspecialty training in bariatrics to the present training of gastrointestinal fellows needs to be reconsidered. This approach should be facilitated by gastrointestinal trainees’ prior residency training in subspecialties that provide care for individuals with medical complications of obesity, including endocrinology, cardiology, nephrology, and neurology. Such training could incorporate additional rotations with collaborating providers in bariatric surgery, nutrition, and psychiatry. Since such training would be provided in accredited programs, longitudinal studies could be developed to examine the potential impact on accepted measures of care, such as complication rates, outcomes, and costs, in individuals with medically-complicated obesity.

Presence of Serum Ferritin before and after Bariatric Surgery: Analysis in Dentate and Edentulous Patients

Society has changed its own lifestyle, specially its eating habits and physical activities, leading to excessive weight and a sedentary behavior, which has contributed to obesity increase. Bariatric surgery is the most effective treatment to obesity, allowing weight loss and its maintenance. However, it has been related high levels of iron deficiency after surgery. A person's nutritional status might be affected by total or partial tooth loss. The aim of this longitudinal prospective cohort study was to evaluate the levels of serum ferritin before and after bariatric surgery and to identify if there is a relation with tooth loss. The sample was composed of 50 patients selected and assisted at Amaral Carvalho Hospital, located in Jaú city, Brazil. The use and necessity of prosthesis, dental absence or presence, and serum ferritin dosage were evaluated. Student's t test, Univariate analysis, Chi-square and Odds Ratio were adopted (p<0.05). There was no significant difference regarding the serum ferritin levels between dentate and edentulous patients prior to surgery (p = 0.436). After surgery, the serum ferritin levels were higher in edentulous patients (prosthesis users) when compared to the pre-surgical levels, and the post-surgical levels presented significant difference regarding the dentate patients (p = 0.024). It can be concluded that rehabilitated patients in postoperative period showed better levels of serum ferritin after surgical intervention.

Endoscopic management of post-bariatric surgery complications

Understanding the technical constructs of bariatric surgery is important to the treating endoscopist to maximize effective endoluminal therapy. Post-operative complication rates vary widely based on the complication of interest, and have been reported to be as high as 68% following adjustable gastric banding. Similarly, there is a wide range of presenting symptoms for post-operative bariatric complications, including abdominal pain, nausea and vomiting, dysphagia, gastrointestinal hemorrhage, and weight regain, all of which may provoke an endoscopic assessment. Bleeding and anastomotic leak are considered to be early (< 30 d) complications, whereas strictures, marginal ulcers, band erosions, and weight loss failure or weight recidivism are typically considered late (> 30 d) complications. Treatment of complications in the immediate post-operative period may require unique considerations. Endoluminal therapies serve as adjuncts to surgical and radiographic procedures. This review aims to summarize the spectrum and efficacy of endoscopic management of post-operative bariatric complications.

Changes in Bone Metabolism in Morbidly Obese Patients After Bariatric Surgery: A Meta-Analysis

BACKGROUND

The aim is to evaluate via meta-analysis bone metabolism and bone mineral density (BMD) in morbidly obese patients before and after bariatric surgery.

METHODS

We searched Medline, EMBASE, and the Cochrane Library for relevant studies published before January 2014. The following outcomes were evaluated: serum calcium, serum parathyroid hormone (PTH), serum 25-hydroxyvitamin D [25(OH)D], serum or urinary N-telopeptide (NTX), bone-specific alkaline phosphatase (BSAP), and bone mineral density (BMD).

RESULTS

Ten studies, including 344 patients, met our inclusion criteria. Results showed a significant decrease in serum calcium (MD = -0.10, 95 %CI -0.14 to -0.07, P < 0.00001) and increase in serum PTH (MD = 12.41, 95 %CI 6.51 to 18.31, P < 0.00001) but no significant difference in serum 25(OH)D (MD = 1.35, 95 %CI -1.12 to 3.83, P = 0.28) following bariatric surgery. There were significant increases in serum or urinary NTX (MD = 18.49, 95 %CI 3.33 to 33.66, P = 0.02) and BSAP (MD = 7.47, 95 %CI 0.21 to 14.72, P = 0.04) but a significant decrease in BMD (MD = -0.08, 95 %CI -0.13 to -0.04, P < 0.00001) after bariatric surgery.

CONCLUSION

BMD was significantly decreased, while bone turnover was elevated, and bone remodeling was accelerated following bariatric surgery. Basal bone metabolism should be evaluated preoperatively. To prevent secondary hyperparathyroidism and bone loss, calcium and vitamin D should be monitored closely and supplemented accordingly after the surgery.

Preconception counseling after bariatric surgery

Obesity has increased exponentially in the United States, affecting over 78 million individuals. As the rates of obesity increase, providers encounter more women with a history of bariatric surgery. Certain bariatric procedures can change how essential nutrients are absorbed. Preconception counseling assists in identifying potential deficiencies early.

Breath Hydrogen as a Biomarker for Glucose Malabsorption after Roux-en-Y Gastric Bypass Surgery

Objective. Abdominal symptoms are common after bariatric surgery, and these individuals commonly have upper gut bacterial overgrowth, a known cause of malabsorption. Breath hydrogen determination after oral glucose is a safe and inexpensive test for malabsorption. This study is designed to investigate breath hydrogen levels after oral glucose in symptomatic individuals who had undergone Roux-en-Y gastric bypass surgery. Methods. This is a retrospective study of individuals (n = 63; 60 females; 3 males; mean age 49 years) who had gastric bypass surgery and then glucose breath testing to evaluate abdominal symptoms. Results. Among 63 postoperative individuals, 51 (81%) had a late rise (≥45 minutes) in breath hydrogen or methane, supporting glucose malabsorption; 46 (90%) of these 51 subjects also had an early rise (≤30 minutes) in breath hydrogen or methane supporting upper gut bacterial overgrowth. Glucose malabsorption was more frequent in subjects with upper gut bacterial overgrowth compared to subjects with no evidence for bacterial overgrowth (P < 0.001). Conclusion. These data support the presence of intestinal glucose malabsorption associated with upper gut bacterial overgrowth in individuals with abdominal symptoms after gastric bypass surgery. Breath hydrogen testing after oral glucose should be considered to evaluate potential malabsorption in symptomatic, postoperative individuals.

Anaemia and related nutrient deficiencies after Roux-en-Y gastric bypass surgery: a systematic review and meta-analysis

OBJECTIVE

To obtain a pooled risk estimate on the long-term impact of anaemia and related nutritional deficiencies in patients receiving Roux-en-Y gastric bypass (RYGB) surgery.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE and Cochrane databases were searched to identify English reports published before 16 May 2014.

ELIGIBILITY CRITERIA

Articles with case numbers >100, follow-up period >12 months, and complete data from both before and after surgery were selected. Outcomes of interest were changes in baseline measurements of proportion of patients with anaemia, by haemoglobin, haematocrit, ferritin, iron, vitamin B12 and folate levels.

DATA COLLECTION AND ANALYSIS

Two reviewers independently reviewed data and selected six prospective and nine retrospective studies with a total of 5909 patients. A random effect model with inverse variance weighting was used to calculate summary estimates of outcomes at 6, 12, 24 and 36 months postoperatively.

RESULTS

Proportion of patients with anaemia was 12.2% at baseline, which, respectively, increased to 20.9% and 25.9% at 12 and 24 months follow-up, consistent with decreases in haemoglobin and haematocrit levels. Although the serum iron level did not change substantially after surgery, the frequency of patients with ferritin deficiency increased from 7.9% at baseline to 13.4% and 23.0% at 12 and 24 months, respectively, postoperation. Vitamin B12 deficiency increased from 2.3% at baseline to 6.5% at 12 months after surgery in those subjects receiving RYGB. There was no obvious increase in folate deficiency.

CONCLUSIONS

RYGB surgery is associated with an increased risk of anaemia and deficiencies of iron and vitamin B12, but not folate. Ferritin is more sensitive when serum iron level is within normal range.

Review article: The nutritional and pharmacological consequences of obesity surgery

BACKGROUND

Obesity surgery is acknowledged as a highly effective therapy for morbidly obese patients. Beneficial short-term effects on common comorbidities are practically undisputed, but a growing data pool from long-term follow-up reveals increasing evidence of potentially severe nutritional and pharmacological consequences.

AIMS

To assess the prevalence, causes and symptoms of complications after obesity surgery, to elucidate and compare therapy recommendations for macro- and micronutrient deficiencies, and to explore surgically-induced effects on drug absorption and bioavailability, discussing ramifications for long-term therapy and prophylaxis.

METHODS

PubMed, Embase and MEDLINE were searched using terms including, but not limited to, bariatric surgery, gastric bypass, obesity surgery and Roux-en-Y, coupled with secondary search terms, e.g. anaemia, micronutrients, vitamin deficiency, bacterial overgrowth, drug absorption, pharmacokinetics, undernutrition. All studies in English, French or German published January 1980 through March 2014 were included.

RESULTS

Macro- and micronutrient deficiencies are common after obesity surgery. The most critical, depending on surgical technique, are hypoalbuminemia (3-18%) and deficiencies of vitamins B1 (≤49%), B12 (19-35%) and D (25-73%), iron (17-45%) and zinc (12-91%). Many drugs commonly administered to obese patients (e.g. anti-depressants, anti-microbials, metformin) are subject to post-operative and/or PPI-associated changes affecting bioavailability and absorption.

CONCLUSIONS

Complications are associated with pre-operative and/or post-operative malnutrition or procedure-related changes in intake, absorption and drug bioavailability. The high prevalence of nutrient deficiencies after obesity surgery makes life-long nutritional monitoring and supplementation essential. Post-operative changes to drug absorption and bioavailability in bariatric patients cast doubt on the validity of standard drug dosage and administration recommendations.

The neurologic complications of bariatric surgery

Bariatric surgery has been increasingly employed to manage morbid obesity. Approximately 150000 bariatric procedures are performed in the US annually. Neurologic complications arise in as many as 5% of individuals having this surgery. Although the etiology of some of these complications remains obscure, the majority are the consequence of vitamin (most commonly thiamine and vitamin B12) or mineral (most commonly copper) deficiency and familiarity with these disorders is essential. Their rapid diagnosis and appropriate treatment is essential to avoid long-term, irreversible consequences including, in some instances, death.

Role of the gastroenterologist in managing obesity

Obesity has become a major public health problem as a consequence of its prevalence, negative impact on morbidity, mortality and quality of life and its associated direct and indirect healthcare costs. The etiology of obesity is multifactorial and reflects complex interactions of genetic, neurohumoral, environmental, behavioral and possibly, microbial factors. Available treatments for obesity include diet and exercise, behavioral modification, medications and surgery. Gastroenterologists are becoming increasingly involved in the care of obese patients. Although much of this care has historically centered on the preoperative and postoperative care of the bariatric patient, gastroenterologists are also evaluating and managing a variety of gastrointestinal symptoms and disorders that occur more commonly among obese individuals and are increasingly involved in the primary treatment of obesity. In this review, the gastrointestinal symptoms and disorders that are associated with obesity will be reviewed, the gastrointestinal contribution to the pathogenesis of obesity will be described and the current treatment options of obesity and where the gastroenterologist typically plays a role in the management will be discussed.

Vitamin, mineral, and drug absorption following bariatric surgery

The prevalence of obesity continues to rise throughout the world. Increasingly, bariatric surgery is used for those with morbid obesity as a pivotal approach to achieve weight loss. Along with substantial weight loss, malabsorption of essential vitamins, minerals, and drugs also occurs. Therefore, more than ever, a better understanding of the physiology and mechanisms by which these deficiencies occur is essential. We review the normal physiology of vitamin, mineral, and drug absorption. This is followed by a description of currently performed bariatric surgeries in the United States. A detailed review of specific nutrient and mineral deficiency states is presented, based on the most significant studies published in the last two decades. Of note, screening and supplementation recommendations have been included. Drug absorption data after these procedures is presented and discussed. Studies were identified by searching the Cochrane Registry and MEDLINE using relevant search terms, as well as through review of the reference section of included manuscripts.

CONCLUSIONS

Bariatric surgery can be effectively used to achieve sustainable weight-loss in morbidly obese patients. It simultaneously brings forth important functional consequences on nutrient deficiencies and drug absorption that clinician's must be aware of. Further prospective, randomized research on specific procedures and deficiencies is required.

Obesity and brain addiction circuitry: implications for deep brain stimulation

Obesity is a growing health problem worldwide and is responsible for a significant proportion of health expenditures in developed nations. It is also notoriously difficult to treat. Prior attempts at pharmacological or neurological modulation, including deep brain stimulation, have primarily targeted homeostatic mechanisms of weight control centered in the hypothalamus. To date, these attempts have had limited success. Multiple lines of independent data suggest that dysregulated reward circuitry in the brain underlies behaviors leading to obesity. Here, we review the existing data and related neurocircuitry, as well as the scope of obesity and currently available treatments. Finally, we suggest a neuromodulation strategy geared toward regulating these dysfunctional circuits, primarily by alteration of frontolimbic circuits.

Pharmacotherapies for Overeating and Obesity

Obesity has become pandemic, and the annual cost in related illnesses and loss of productivity is already over $100 billion and rising. Research has shown that obesity can and does cause changes in behavior and in the brain itself that are very similar to changes caused by drugs of abuse. While food addiction is not the causal agent of all obesity, it is clear that many people no longer eat to survive, but instead survive to eat. This review considers the importance of the brain's reward system in food intake. The review also examines research developments and current treatments for obesity, including diet and exercise, psychotherapy, surgical interventions, and pharmacotherapies. Finally we discuss alterations in American society that are necessary for change to occur, and the diffculties therein.

Nutritional deficiencies after bariatric surgery

Lifestyle intervention programmes often produce insufficient weight loss and poor weight loss maintenance. As a result, an increasing number of patients with obesity and related comorbidities undergo bariatric surgery, which includes approaches such as the adjustable gastric band or the 'divided' Roux-en-Y gastric bypass (RYGB). This Review summarizes the current knowledge on nutrient deficiencies that can develop after bariatric surgery and highlights follow-up and treatment options for bariatric surgery patients who develop a micronutrient deficiency. The major macronutrient deficiency after bariatric surgery is protein malnutrition. Deficiencies in micronutrients, which include trace elements, essential minerals, and water-soluble and fat-soluble vitamins, are common before bariatric surgery and often persist postoperatively, despite universal recommendations on multivitamin and mineral supplements. Other disorders, including small intestinal bacterial overgrowth, can promote micronutrient deficiencies, especially in patients with diabetes mellitus. Recognition of the clinical presentations of micronutrient deficiencies is important, both to enable early intervention and to minimize long-term adverse effects. A major clinical concern is the relationship between vitamin D deficiency and the development of metabolic bone diseases, such as osteoporosis or osteomalacia; metabolic bone diseases may explain the increased risk of hip fracture in patients after RYGB. Further studies are required to determine the optimal levels of nutrient supplementation and whether postoperative laboratory monitoring effectively detects nutrient deficiencies. In the absence of such data, clinicians should inquire about and treat symptoms that suggest nutrient deficiencies.

Neurologic complications of bariatric surgery: involvement of central, peripheral, and enteric nervous systems

Approximately one in three Americans is obese. Current society guidelines recommend bariatric surgery after conservative measures at weight loss have failed. The frequency of bariatric surgeries has increased significantly over the past decade. While considered both safe and effective, bariatric surgery presents a distinct set of risks. This review focuses on the neurological complications of bariatric surgery. Injuries have been reported at all levels of the nervous system, including the central, peripheral, and enteric nervous system. Injury can be classified according to time of presentation and location. The two main mechanisms of nerve injury are from mechanical injury or as a consequence of malnutrition. Encephalopathy, peripheral neuropathies, myelopathies, and radiculoneuropathies have all been reported. Mechanical injuries likely occur from mechanical compression. Malnutrition injuries result from multi-micronutrient deficiencies. The most likely candidates are vitamin B12, folate, zinc, thiamin, copper, vitamin A, and vitamin E deficiencies.

Origins of and recognition of micronutrient deficiencies after gastric bypass surgery

Roux-en-Y gastric bypass surgery remains the major surgical option for individuals with medically complicated obesity. The importance of preoperative evaluation to permit identification of micronutrient deficiencies is being re-evaluated. The risk of complications related to pregnancy after gastric bypass supports careful follow-up. Micronutrient deficiencies are common in postoperative gastric bypass patients, despite the suggested use of routine vitamin and mineral supplements after surgery. Copper deficiency must be considered as an origin for visual disorders after gastric bypass. Vitamin D deficiency with metabolic bone disease remains common after gastric bypass and the results suggest that the present postoperative supplements of calcium and vitamin D are inadequate. Major nutritional complications of bariatric surgery are occurring more than 20 years after surgery. There is no evidence for intestinal adaptation as there remains decreased intestinal absorption of iron up to 18 months after gastric bypass surgery. This article supports ongoing examination of nutritional complications after gastric bypass surgery and supports the notion that the daily doses of micronutrient supplements, such as vitamin D, may need to be revised.

Endoscopic management in the bariatric surgical patient

PURPOSE OF REVIEW

Morbid obesity is a global health epidemic. As the prevalence of bariatric surgery rises, it becomes increasingly important for gastroenterologists to understand their role in the perioperative care of bariatric surgical patients, to recognize potential complications of surgery that can be addressed endoscopically, and to learn about endoluminal approaches that may provide alternatives to bariatric surgery in the future.

RECENT FINDINGS

Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric band account for more than 80% of weight loss procedures performed worldwide. Over two-thirds of patients with upper gastrointestinal symptoms following RYGB will have one or more abnormalities on endoscopy, including anastomotic strictures (53%), marginal ulcers (16%), functional obstructions (4%), and gastrogastric fistulas (2.6%). Intraoperative endoscopy can detect early leaks in over 7% of patients during RYGB surgery. Single-center experience finds that endoscopic repair of small gastrogastric fistulas is technically feasible in 95% of patients; however, durability of closure remains limited. Pooled data demonstrate that balloon-assisted endoscopic retrograde cholangiopancreatography can achieve papillary cannulation in 80% of patients with RYGB anatomy.

SUMMARY

The gastroenterologist can improve outcomes in bariatric surgical patients by understanding the issues of care that present themselves perioperatively and that lend themselves to minimally invasive endoscopic treatments.