Advances in the surgical treatment of morbid obesity

Effects of bariatric surgery on bone metabolism: focusing on vitamin D

The main goal of bariatric surgery is weight loss due to fundamental differential changes in the anatomical and physiological characteristics of the gastrointestinal tract. At the same time, one of the most frequent complications of obesity surgery, especially operations associated with malabsorption, is vitamin D deficiency. Patients with obesity initially have a wide range of predisposing factors for metabolic diseases of the skeleton due to lifestyle problems. Nutrient deficiencies with high-calorie diets and a sedentary lifestyle with a tendency to wear clothing that covers most of the skin — reduces serum 25 (OH) D levels. In addition, the situation is aggravated by a decrease in the bioavailability of 25 (OH) D due to its sequestration in adipose tissue and its complete inaccessibility to the central blood flow. The consequences of bariatric surgery — a decrease in the amount of skin and malabsorption can aggravate the existing deficiency. As a result of a decrease in the level of 25 (OH) D and subsequent hypocalcemia and secondary hyperparathyroidism, negatively affect the state of bone health. The presented literature review is devoted to the problems of obesity surgery and vitamin D deficiency. The main focus is on bone metabolism associated with bariatric surgery, the causes of pre and postoperative vitamin D deficiency are discussed, and recommendations for its treatment after obesity surgery are given.

 

Symptomatic Hypoglycemia After Gastric Bypass: Incidence and Predictive Factors in a Cohort of 1,138 Consecutive Patients

OBJECTIVE

After Roux-en-Y gastric bypass (RYGB), postprandial hyperinsulinemic hypoglycemia (PPHH) is particularly critical because of the risk of trauma. The aim of this study was to assess the incidence and identify risk factors for symptomatic PPHH.

METHODS

Patients with RYGB were classified into moderate PPHH (MH) or severe hypoglycemia (SH), which is defined as patients with neuroglycopenic symptoms. Logistic multivariate linear regressions were performed to identify predictive factors for symptomatic PPHH and more specifically for SH with neuroglycopenic symptoms. Patients with diabetes and those with a follow-up shorter than 2 years were excluded.

RESULTS

Among the 1,138 patients, 44.2% had at least one episode of hypoglycemia with a mean delay of 25.5 (21.3) months, 32.6% had MH, and 11.6% had SH. The annual incidence rate of SH was 2.5% the first year, 3.7% the second year, and 1.5% the third year. Independent predictive factors for higher risk of SH were: younger age (odds ratio [OR] = 1.01; 95% CI: 1.05-16.69; P = 0.0007), lower BMI after RYGB (OR = 1.61; 95% CI: 1.17-2.22; P = 0.0035), and maximal weight loss (OR = 1.04; 95% CI = 1.39-1.23; P = 0.0106), whereas higher preoperative BMI was protective (OR = 0.78; 95% CI: 0.64-0.95; P = 0.0112).

CONCLUSIONS

This observational cohort study showed that the incidence of severe PPHH with neuroglycopenic symptoms after RYGB was higher than expected.

Dietary Energy Partition: The Central Role of Glucose

Humans have developed effective survival mechanisms under conditions of nutrient (and energy) scarcity. Nevertheless, today, most humans face a quite different situation: excess of nutrients, especially those high in amino-nitrogen and energy (largely fat). The lack of mechanisms to prevent energy overload and the effective persistence of the mechanisms hoarding key nutrients such as amino acids has resulted in deep disorders of substrate handling. There is too often a massive untreatable accumulation of body fat in the presence of severe metabolic disorders of energy utilization and disposal, which become chronic and go much beyond the most obvious problems: diabetes, circulatory, renal and nervous disorders included loosely within the metabolic syndrome. We lack basic knowledge on diet nutrient dynamics at the tissue-cell metabolism level, and this adds to widely used medical procedures lacking sufficient scientific support, with limited or nil success. In the present longitudinal analysis of the fate of dietary nutrients, we have focused on glucose as an example of a largely unknown entity. Even most studies on hyper-energetic diets or their later consequences tend to ignore the critical role of carbohydrate (and nitrogen disposal) as (probably) the two main factors affecting the substrate partition and metabolism.

Ileal bezoar causing bowel obstruction mimicking an internal hernia in a patient with Roux-en-Y gastric bypass

We presented a case of a 64-year-old female patient with a history of gastric bypass that presented with bowel obstruction due to a bezoar. She arrived at the emergency department, referring to severe abdominal pain, nausea, and vomiting. Abdominal X-ray reported gastric distention and hydro-air levels. CT scan reported swirling of the mesentery vessels and a collapsed intestinal loop, mimicking an internal hernia. Laparotomy was accomplished, which shows obstruction at 60 cm from the ileocecal valve. An enterolithotomy was performed, and a 6 × 6 cm phytobezoar was extracted. The patient had a satisfactory postoperative outcome, discharging her home on the fourth postoperative day. On a 12 month-follow up, the patient is doing well with no further complications. Gastric bypass continues to be one of the most performed bariatric procedures with low complication rates. It is important to note that not all intestinal obstructions in postoperative bariatric surgeries are due to internal hernias or adhesions. The differential diagnosis of intestinal obstruction due to bezoar must be present in patients who underwent bariatric surgery. Nutritional counseling is essential for the follow-up of patients, emphasizing fluid intake and slow chewing, as well as the use of absorbable materials for suture during the surgery.

Stimulating the nucleus accumbens in obesity: A positron emission tomography study after deep brain stimulation in a rodent model

PURPOSE

The nucleus accumbens (NAcc) has been suggested as a possible target for deep brain stimulation (DBS) in the treatment of obesity. Our hypothesis was that NAcc-DBS would modulate brain regions related to reward and food intake regulation, consequently reducing the food intake and, finally, the weight gain. Therefore, we examined changes in brain glucose metabolism, weight gain and food intake after NAcc-DBS in a rat model of obesity.

PROCEDURES

Electrodes were bilaterally implanted in 2 groups of obese Zucker rats targeting the NAcc. One group received stimulation one hour daily during 15 days, while the other remained as control. Weight and daily consumption of food and water were everyday registered the days of stimulation, and twice per week during the following month. Positron emission tomography (PET) studies with 2-deoxy-2-[18F]fluoro-D-glucose (FDG) were performed 1 day after the end of DBS. PET data was assessed by statistical parametric mapping (SPM12) software and region of interest (ROI) analyses.

RESULTS

NAcc-DBS lead to increased metabolism in the cingulate-retrosplenial-parietal association cortices, and decreased metabolism in the NAcc, thalamic and pretectal nuclei. Furthermore, ROIs analyses confirmed these results by showing a significant striatal and thalamic hypometabolism, and a cortical hypermetabolic region. However, NAcc-DBS did not induce a decrease in either weight gain or food intake.

CONCLUSIONS

NAcc-DBS led to changes in the metabolism of regions associated with cognitive and reward systems, whose impairment has been described in obesity.

Long term maintenance of glucose and lipid concentrations after Roux-en-Y gastric bypass

OBJECTIVE

Roux-en-Y gastric bypass (RYGB) reduces body weight and the comorbidities associated with obesity. The aim of this study was to evaluate whether glucose and lipid profiles were maintained during a 5-year follow-up period after RYGB.

SUBJECTS AND METHODS

Anthropometric and laboratory data from 323 patients who had undergone this operation were analyzed. Differences in laboratory variables between the baseline and 12, 24, 36, 48 and 60 months postoperatively (PO) were assessed using a one-way ANOVA test to compare the three groups. Delta significance using one-way ANOVA was performed to assess anthropometric variable in the postoperative period (p < 0.05).

RESULTS

77 patients (24%) were included in Group 1 (G1), 101 (32%) in Group 2 (G2), and 141 (44%) in Group 3 (G3). The majority of patients, 71.7% in G1, 82.8% in G2, and 70% in G3, showed high triglycerides (TG) before surgery. A decrease in weight loss was observed in all groups followed by an increase in body weight in G2 and G3 at 36, 48 and 60 months. Laboratory results for G1, G2 and G3 showed no significant differences between groups at baseline and during the post-operative period.

CONCLUSION

Our results suggest that weight regain after RYGB has no significant impact on the long-term evolution of the lipid profile and glycemia.

Revisional Laparoscopic Sleeve Gastrectomy in failed gastric banding and effects of exercise and frequent sweet-eating on its outcome

Objective:

To find out effectiveness of revisional laparoscopic sleeve gastrectomy (RLSG) in the patients who had laparoscopic adjustable gastric banding (LAGB) and failed to reduce or regained the weight and effectiveness of sweet abstaining and exercise on postoperative weight loss.

Methods:

This retrospective observational study was conducted at AlMoosa Hospital, Al-Ahsa, Kingdom of Saudi Arabia from December 2011 to November 2016. The patients who failed to reduce, regained the weight or had complications after LAGB, were performed RLSG. They were followed-up at three, six, twelve and twenty-four months intervals. Their weight, percent excess weight loss (%EWL) and body mass index (BMI) at pre-RLSG were compared with post-RLSG. The data was recorded in SPSS 22 and analyzed.

Results:

Thirty-six patients with male/female ratio of 1:5 underwent RLSG. Twelve (33.3%) were frequent sweet-eaters and twenty-four (66.7%) were not. Fourteen (38.88%) did not have exercise, while twenty-two (61.11%) had daily regular exercise. Their mean pre-RLSG weight, percent excess weight loss (%EWL)and BMI were compared with post-RLSG at the period of three, six, twelve and twenty-four months. Their mean weight reduced from 111.69 kilograms to 96.94, 87.25, 79.56 and 76.11 kilograms respectively. Their mean of the percent excess weight loss (%EWL) reduced to 22.08, 45.75, 59.64 and 66.42 kilograms respectively. Their mean pre-RLSG BMI was 43.50 kg.m^-2, which reduced to the mean of 37.79, 34.02, 30.97 and 29.70 respectively. There were no post-operative complications in thirty (83.3%), mild like wound infection and seroma in four (11.1%) and bleeding in two (5.6%) patients. None of the patients had leakage. The patients who kept themselves abstained from sweet consumption and performed regular postoperative exercise had better results. They also had considerable reduction in appetite after RLSG.

Conclusion:

RLSG is an effective procedure after failed LAGB in terms of weight loss having minimal rate of complications. Moreover, abstaining from sweet consumption and continuing exercise postoperatively has better results.

Surgical Endoscopy Versus Endoscopic Surgery for Obesity

BACKGROUND

Obesity treatment options are of great interest worldwide with major developments in the past 20 years. From general surgery to natural orifice transluminal endoscopic surgery intervention nowadays, obesity surgical therapies have surely developed and are now offering a variety of possibilities.

AREAS OF UNCERTAINTY

Although surgery is the only proven approach for weight loss, a joint decision between the physician and patient is required before proceeding to such a procedure. With a lot of options available, the treatment should be individualized because the benefits of surgical intervention must be weighed against the surgical risks.

DATA SOURCES

Medline search to locate full-text articles and abstracts with obvious conclusions by using the keywords: obesity, surgical endoscopy, gastric bypass, bariatric surgery, and endoscopic surgery, alone and in various combinations. Additional relevant publications were also searched using the reference lists of the identified articles as a starting point.

RESULTS

Laparoscopic Roux-en-Y gastric bypass still is the most effective, less invasive, bariatric surgical intervention, although there are various complications encountered, such as postoperative hemorrhage (1.9%-4.4%), internal hernias, anastomotic strictures (2.9%-23%), marginal ulcerations (1%-16%), fistulas (1.5%-6%), weight gain, and nutritional deficiencies. However, the absence of parietal incisions, less pain, decreased risk of infection, and short hospital stay make room for endoscopic surgery as a possible valid option for obesity for both the doctors' and the patients' perspective.

CONCLUSIONS

The current tendency is to promote surgical treatment of obesity to a status of less invasive scars therefore promoting minimally invasive surgical techniques.

Vitamin D alteration associated with obesity and bariatric surgery

Obesity and severe obesity constitute growing serious health problems reaching epidemic proportion in most countries. Interactions and relationships between obesity and bone tissue and its metabolism are complex but are more and more studied and recognized. Obesity is associated with an altered hormonal profile including particularly bone-regulating hormones like vitamin D. Bariatric surgery procedures, thanks to their effectiveness to achieve therapeutic endpoints for comorbidities associated with obesity, have had an increasing success. However, these surgeries by producing mechanical restriction and or malabsorption syndrome lead to nutritional deficiencies including vitamin D. In this review, we aim to (1) discuss the nutritional deficiency of vitamin D in the obese, (2) to summarize the different surgical options in bariatric surgery and to present the evidence concerning these procedures and their associated profile in vitamin D post-operative insufficiency, (3) to present the different recommendations in clinical practice to prevent or treat vitamin D deficiencies or insufficiencies in patients treated by bariatric surgery and finally to introduce emerging assumptions on the relationship between vitamin D, microbiota composition and circulating bile acids. Impact statement Obesity and severe obesity constitute growing serious health problems reaching epidemic proportion in most countries with a prevalence increasing from 6.4 in 1975 to 14.9% in 2014. This present review summarizes currently available data on vitamin D deficiencies in the obese population before and after bariatric surgery. The important evidence emerging from our evaluation confirms that obese patients are at risk of multiple nutritional deficiencies, especially vitamin D deficiency, before bariatric surgery. Our survey confirms that the precise role of the gut microbiome and its associated changes on the vitamin D metabolism after the different bariatric surgery procedures has not yet been studied. Furthermore, whether differences in the microbiota may alter the therapeutic responses to vitamin D is not known.

Metabolic syndrome and the hepatorenal reflex

Insufficient hepatic O₂ in animal and human studies has been shown to elicit a hepatorenal reflex in response to increased hepatic adenosine, resulting in the stimulation of renal as well as muscle sympathetic nerve activity and activating the renin angiotensin system. Low hepatic ATP, hyperuricemia, and hepatic lipid accumulation reported in metabolic syndrome (MetS) patients may reflect insufficient hepatic O₂ delivery, potentially accounting for the sympathetic overdrive associated with MetS. This theoretical concept is supported by experimental results in animals fed a high fructose diet to induce MetS. Hepatic fructose metabolism rapidly consumes ATP resulting in increased adenosine production and hyperuricemia as well as elevated renin release and sympathetic activity. This review makes the case for the hepatorenal reflex causing sympathetic overdrive and metabolic syndrome in response to exaggerated splanchnic oxygen consumption from excessive eating. This is strongly reinforced by the fact that MetS is cured in a matter of days in a significant percentage of patients by diet, bariatric surgery, or endoluminal sleeve, all of which would decrease splanchnic oxygen demand by limiting nutrient contact with the mucosa and reducing the nutrient load due to loss of appetite or dietary restriction.

Metabolic syndrome and the hepatorenal reflex

Insufficient hepatic O₂ in animal and human studies has been shown to elicit a hepatorenal reflex in response to increased hepatic adenosine, resulting in stimulation of renal as well as muscle sympathetic nerve activity and activating the renin angiotensin system. Low hepatic ATP, hyperuricemia, and hepatic lipid accumulation reported in metabolic syndrome (MetS) patients may reflect insufficient hepatic O₂ delivery, potentially accounting for the sympathetic overdrive associated with MetS. This theoretical concept is supported by experimental results in animals fed a high fructose diet to induce MetS. Hepatic fructose metabolism rapidly consumes ATP resulting in increased adenosine production and hyperuricemia as well as elevated renin release and sympathetic activity. This review makes the case for the hepatorenal reflex causing sympathetic overdrive and metabolic syndrome in response to exaggerated splanchnic oxygen consumption from excessive eating. This is strongly reinforced by the fact that MetS is cured in a matter of days in a significant percentage of patients by diet, bariatric surgery, or endoluminal sleeve, all of which would decrease splanchnic oxygen demand by limiting nutrient contact with the mucosa and reducing the nutrient load due to the loss of appetite or dietary restriction.

Sleeve gastrectomy leads to weight loss in the Magel2 knockout mouse

BACKGROUND

Prader-Willi syndrome (PWS) is a genetic disorder characterized by hyperphagia, obesity, cardiopulmonary diseases, and increased mortality. Although successful weight loss improves health in PWS, few treatments cause sustained weight loss in obese patients let alone obese individuals with PWS.

OBJECTIVES

The present study uses the Magel2 knockout (KO) mouse, an animal model of PWS, to conduct a preclinical study on the efficacy of sleeve gastrectomy (SG) in PWS.

SETTING

Academic research laboratory, United States.

METHODS

We performed sham or SG surgeries in 24- to 28-week-old male Magel2 KO and wild-type littermate control mice (WT) who had been maintained on a high-fat diet for 10 weeks. We monitored weight, food intake, and fat and lean mass pre- and postoperatively. Fasting glucose, glucose tolerance, and counter-regulation were measured postoperatively.

RESULTS

Magel2 KO animals had similar recovery and mortality rates compared with WT. SG resulted in similar weight loss, specifically loss of fat but not lean mass, in both Magel2 KO and WT mice. SG also resulted in significantly lower fasting glucose levels and a reduction in fat intake in both Magel2 KO and WT mice. We also found that Magel2 KO mice failed to increase their food intake in response to the glucoprivic agent 2-deoxy-D-glucose, suggesting impaired glucose counter-regulation, but this occurred regardless of surgical status. All results were considered significant when P< .05.

CONCLUSION

We find in this mouse model of PWS, SG is a well-tolerated, effective strategy for weight and fat loss.

Energy and macronutrient intake after gastric bypass for morbid obesity: a 3-y observational study focused on protein consumption

BACKGROUND

The effect of a Roux-en-Y gastric bypass (RYGB) on body weight has been amply documented, but few studies have simultaneously assessed the evolution of energy and macronutrient intakes, energy expenditure, and changes in body composition over time after an RYGB.

OBJECTIVE

We evaluated energy and macronutrient intakes, body composition, and the basal metabolic rate (BMR) in obese female patients during the initial 3 y after an RYGB.

METHODS

Sixteen women with a mean ± SEM body mass index (in kg/m(2)) of 44.1 ± 1.6 were included in this prospective observational study. The women were studied on 6 different occasions as follows: before and 1, 3, 6, 12 (n = 16), and 36 (n = 8) mo after surgery. On each occasion, food intake was evaluated from 4- or 7-d dietary records, body composition was assessed with the use of bio-impedancemetry, and energy expenditure was measured with the use of indirect calorimetry.

RESULTS

Body weight evolution showed the typical pattern reported after an RYGB. Total energy intake was 2072 ± 108 kcal/d at baseline and decreased to 681 ± 58 kcal/d at 1 mo after surgery (P < 0.05 compared with at baseline). Total energy intake progressively increased to reach 1240 ± 87 kcal/d at 12 mo after surgery (P < 0.05 compared with at 1 mo after surgery) and 1448 ± 57 kcal/d at 36 mo after surgery (P < 0.05 compared with at 12 mo after surgery). Protein intake was 87 ± 4 g/d at baseline and ± 2 g/d 1 mo after surgery (P < 0.05 compared with at baseline) and increased progressively thereafter to reach 57 ± 3 g/d at 36 mo after surgery (P < 0.05 compared with at 1 mo after surgery). Carbohydrate and fat intakes over time showed similar patterns. Protein intake from meat and cheese were significantly reduced early at 1 mo after surgery but increased thereafter (P < 0.05). The BMR decreased from 1.12 ± 0.04 kcal/min at baseline to 0.93 ± 0.03, 0.86 ± 0.03, and 0.85 ± 0.04 kcal/min at 3, 12, and 36 mo after surgery, respectively (all P < 0.05 compared with at baseline).

CONCLUSIONS

Total energy, carbohydrate, fat, and protein intakes decreased markedly during the initial 1-3 mo after an RYGB, whereas the BMR moderately decreased. The reduction in protein intake was particularly severe at 1 mo after surgery, and protein intake increased gradually after 3-6 mo after surgery. This trial was registered at clinicaltrials.gov as NCT01891591.

Bowel obstruction rates in antecolic/antegastric versus retrocolic/retrogastric Roux limb gastric bypass: a meta-analysis

BACKGROUND

Previous literature is varied with regard to rates of bowel obstruction after laparoscopic Roux-en-Y gastric bypass (LRYGB). Internal herniation through mesenteric defects is a common cause of bowel obstructions. There are advantages and disadvantages to routing the Roux limb via a retrocolic/retrogastric (RC/RG) versus an antecolic/antegastric (AC/AG) position.

OBJECTIVE

To review the literature comparing obstruction rates in RYGB using the antecolic versus retrocolic approach.

SETTING

Community-based integrated multispecialty health system with a teaching hospital serving 19 counties over a 3-state region.

METHODS

A literature search for articles published from 1994-2013 was completed. Articles were included if they reported an n>25, Roux limb route, obstruction rate by route, and follow-up duration. Statistical analysis included χ(2) test by patient number.

RESULTS

The initial search identified 241 articles; 8 met inclusion criteria. There were 4805 patients in the AC/AG group, and 2238 in the RC/RG group. Follow-up ranged from 0 to 68 months. A linear stapled technique was reported in 4231 (88%) patients in the AC/AG group and 1541 (69%) of RC/RG group. Handsewn closure of mesenteric defects was reported in 2152 (45%) patients in the AC/AG group and 1012 (45%) patients in the RC/RG group. Bowel obstructions occurred in 68 (1.4%) patients in the AC/AG group and 117 (5.2%) patients in the RC/RG group (P<.001). Internal hernias were reported in 65 (1.3%) patients in the AC/AG group and 52 (2.3%) patients in the RC/RG group (P<.001). Two mortalities were reported in the AC/AG group.

CONCLUSIONS

Increased rates of bowel obstruction and internal hernia were observed in the RC/RG group compared with the AC/AG group. A prospective, randomized trial would be necessary to definitively determine the impact of Roux limb position and routine closure of mesenteric defects on bowel obstruction rates after gastric bypass.

Modulation of gut microbiota in the management of metabolic disorders: the prospects and challenges

The gut microbiota plays a number of important roles including digestion, metabolism, extraction of nutrients, synthesis of vitamins, prevention against pathogen colonization, and modulation of the immune system. Alterations or changes in composition and biodiversity of the gut microbiota have been associated with many gastrointestinal tract (GIT) disorders such as inflammatory bowel disease and colon cancer. Recent evidence suggests that altered composition and diversity of gut microbiota may play a role in the increased prevalence of metabolic diseases. This review article has two main objectives. First, it underscores approaches (such as probiotics, prebiotics, antimicrobial agents, bariatric surgery, and weight loss strategies) and their prospects in modulating the gut microbiota in the management of metabolic diseases. Second, it highlights some of the current challenges and discusses areas of future research as it relates to the gut microbiota and metabolic diseases. The prospect of modulating the gut microbiota seems promising. However, considering that research investigating the role of gut microbiota in metabolic diseases is still in its infancy, more rigorous and well-designed in vitro, animal and clinical studies are needed.

Adolescent bariatric surgery: the Canadian perspective

Canada faces a similar epidemic of obesity in their adolescent population as other Western countries. However, the development of programs to treat obesity and manage its sequelae has evolved in a unique way. This is in part due to differences in health care funding, population distribution, public demand, and availability of expertise and resources. In this article, we will describe the evolution of adolescent bariatric care in Canada and describe the current programs and future directions. The focus will be on the province of Ontario, the site of the first adolescent bariatric program in the country.

Forensic Considerations in Bariatric Surgery Patients

Bariatric surgery is gaining in popularity in the United States and around the world as a treatment for morbid obesity. Patients seek surgery in order to lose weight and limit the long-term effects of insulin-resistant diabetes, heart disease and lung disease, including risk of sudden death. While gastric bypass in patients with morbid obesity can reduce the risk of diabetes and myocardial infarction to population levels, the risk of death remains increased. These patients may die suddenly and unexpectedly as a direct result of surgery, as an indirect result of surgery, or of end-organ damage wrought by years of obesity, completely unrelated to the surgery. Proper forensic pathologic assessment of these patients requires an understanding of the anatomic changes caused by bariatric surgery, the complications and the metabolic consequences of the different procedures. In order to better understand this subgroup of patients, a search of the peer-reviewed medical literature at the National Library of Medicine was conducted for articles using the keywords bariatric, surgery, gastric bypass, autopsy, review, toxicology, alcohol, drug, ethanol, absorption, elimination, litigation, forensic, and death. This review outlines the most common laparoscopic and open surgical procedures; the common immediate post-surgical complications that lead to morbidity and mortality; forensic toxicological considerations in bariatric patients; and the long-term complications and other causes that could lead to unexpected death in these patients.