Botulinum A toxin injected into the gastric wall for the treatment of class III obesity: a pilot study

Intragastric injection of botulinum toxin in the treatment of obesity: a single-center study

Background

In recent years, various novel surgical and non-surgical therapeutic options have been developed for treating obesity. Due to its disputed success, intragastric botulinum toxin A (BTX-A) injection is still being debated.

Objectives

We aim to contribute to this controversial issue in the literature by sharing our center's findings regarding intragastric BTX-A injections in the treatment of obesity.

Design

Patients with a body mass index (BMI) of greater than 25 kg/m2 and at least one obesity-related complication, or a BMI of greater than 30 kg/m2 without complications, were eligible for the study if they were between the ages of 18 and 65.

Methods

Following the same procedure, two endoscopists administered BTX-A to all patients. All patients were evaluated for obesity by measuring their lipid profile, hormone profile, and insulin resistance level before treatment.

Results

In our study on 82 patients, we saw a significant mean weight loss (-9.2 kg, p < 0.001) in the second month, and there was no additional mean weight loss in the sixth month of follow-up. In addition, this result seems to be independent of the patient's insulin resistance. We did not see any serious side effects in any of the patients.

Conclusion

Although the use of intragastric injection of BTX-A in the treatment of obesity is a controversial issue, we showed in our study that it causes significant weight loss. Further studies are needed on this subject, as it can be a safe method when the ideal dose and application site are combined with appropriate patient selection.

A large travel-associated outbreak of iatrogenic botulism in four European countries following intragastric botulinum neurotoxin injections for weight reduction, Türkiye, February to March 2023

In March 2023, 34 associated cases of iatrogenic botulism were detected in Germany (30 cases), Switzerland (two cases), Austria (one case), and France (one case). An alert was rapidly disseminated via European Union networks and communication platforms (Food- and Waterborne Diseases and Zoonoses Network, EpiPulse, Early Warning and Response System) and the International Health Regulation mechanism; the outbreak was investigated in a European collaboration. We traced sources of the botulism outbreak to treatment of weight loss in Türkiye, involving intragastric injections of botulinum neurotoxin. Cases were traced using a list of patients who had received this treatment. Laboratory investigations of the first 12 German cases confirmed nine cases. The application of innovative and highly sensitive endopeptidase assays was necessary to detect minute traces of botulinum neurotoxin in patient sera. The botulism notification requirement for physicians was essential to detect this outbreak in Germany. The surveillance case definition of botulism should be revisited and inclusion of cases of iatrogenic botulism should be considered as these cases might lack standard laboratory confirmation yet warrant public health action. Any potential risks associated with the use of botulinum neurotoxins in medical procedures need to be carefully balanced with the expected benefits of the procedure.

Treatment of obesity with intragastric injection of botulinum toxin. Is it worth the pinch? An overview of systematic reviews and meta-analysis

BACKGROUND AND AIMS

Αvaialble evidence regarding the effectiveness of intragastric injection of botulinum toxin in reducing anthropometric indices of subjects with obesity is conflicting. We evaluated the existing evidence and perform a meta-analysis to assess the efficacy of intragastric botulinum toxin in treating obesity.

METHODS

We identified published systematic reviews evaluating the efficacy of intragastric injection of botulinum toxin in patients with overweight or obesity and additionally performed a systematic literature search to retrieve randomized controlled trials on this topic. A random-effects meta-analysis was performed to synthesize the existing studies.

RESULTS

A total of four systematic reviews were included in our overview of systematic reviews and six randomized controlled trials were included in our meta-analysis. Compared to placebo, intragastric injection of botulinum toxin was ineffective in reducing body weight and body mass index after the application of the Knapp-Hartung adjustment (MD = -2.41 kg, 95%CI = -5.21 to 0.38, I² =59% and MD = -1.43 kg/m², 95%CI = -3.04 to 0.18, I² =62%, respectively). Moreover, treatment with intragastric injection with botulinum toxin was not superior to placebo in decreasing waist and hip circumference.

CONCLUSIONS

Based on the available evidence, intragastric injection with botulinum toxin is an ineffective procedure in reducing body weight and body mass index when the Knapp-Hartung method was applied.

[Endoscopic intragastric injection of botulinum toxin in the treatment of patients with morbid obesity: opportunities and prospects]

The authors consider modern epidemiological and demographic data on morbid obesity. Literature review is devoted to non-surgical treatment of patients with morbid obesity. The authors analyze the results of experimental and clinical studies on endoscopic intragastric injection of botulinum toxin and bariatric efficacy of this approach. The indications for endoscopic intragastric injection of botulinum toxin and advantages of this technique are clearly formulated. The authors identified the most significant criteria for objective assessment of clinical effectiveness of endoscopic intragastral injection of botulinum toxin, as well as scientific and methodological principles necessary for this technique. Clinical efficacy of intragastric injection of botulinum toxin including overweight loss, anorexigenic and gastroparetic effects indicates inconsistent results and certain unresolved problems. Thus, large-scale multiple-center randomized controlled trials and multivariate analysis are required to determine the role of endoscopic intragastric injection of botulinum toxin in complex treatment of patients with morbid obesity.

Intragastric injection of botulinum toxin A for weight loss: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Intragastric botulinum toxin A (BTA) injection is a potential treatment for weight reduction in obese patients. Current studies yielded conflicting results. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the efficacy of intragastric BTA injection for weight management.

METHODS

We searched several databases to identify RCTs evaluating intragastric BTA injections for obesity. We applied random-effects models for all meta-analyses due to heterogeneity in the included studies. The mean difference (MD) and 95% confidence interval (CI) were calculated for continuous outcomes.

RESULTS

A total of 6 RCTs including 192 subjects met the inclusion criteria and were included for the meta-analysis. Although the pooled data from six studies showed no difference in the absolute weight loss between intragastric BTA injection and control, subgroup analysis showed a significantly decreased absolute weight after a BTA injection dose ≥ 200 U (MD, -2.04 kg; 95% CI, -3.96 to -0.12) and after multiple injection regions in the stomach combined with diet control (MD, -4.44 kg; 95% CI, -6.54 to -2.33 kg) compared with the control. Regarding absolute weight loss, the impact of endoscopic ultrasound-guided injection and follow-up duration showed no difference. Intragastric BTA injection had a significant change in body mass index (MD, -1.25 kg/m² ; 95% CI, -2.18 to -0.32 kg/m² ) and prolonged gastric half-emptying time (MD, 11.37 min; 95% CI, -3.69 to 19.06 min).

CONCLUSION

Intragastric BTA injection is effective for obesity treatment, and adequate doses (≥ 200 U), multiple gastric injection regions, and combined diet control are crucial. However, given the small sample size and limited power, caution should be exercised.

Can gastric botulinum toxin A injection be used as minimally invasive procedure in the short-term treatment of obesity?

Background/Aim:

Gastric botulinum toxin A (BTX-A) injection is a type of endoscopic obesity treatment option that delays gastric emptying. However, there is little and contradictory information concerning the treatment efficacy of BTX-A injection. This study evaluated the treatment efficacy of BTX-A injection in the treatment of obesity.

Materials and Methods:

This was an open-label, prospective study of obese individuals with a body mass index >30 kg/m² admitted to our clinic. The sample consisted of 72 consecutive treatment-naive patients with obesity divided into age–sex-matched three groups: gastric BTX-A injection (study group), calorie-restricted (15–20 Kcal/kg) diet (control) and bariatric surgery (BS) (control) groups. İn the study group, 200 IU BTX-A was injected to the antrum and corpus endoscopically. The study and control groups were compared for their total body weight loss (TBWL) and excess body weight loss (EBWL) at the 6^th month.

Results:

Gastric BTX-A injection therapy was applied to 24 patients. The mean age was 39.1 ± 9.1/years. 54.1% of the patients (n = 13) was female. At the 6^th month, the mean TBWL and EBWL of patients were; 10% ±4.1 and 37.2% ±13.9 for gastric BTXA injection group, 5% ±2.3 and 20.2% ±9.3 for diet group, 30.7% ±5.3 and 66.9% ±14.4 for BS group. Patients who underwent gastric BTX-A injection lost weight more effectively than patients who were on diet alone, while BS patients lost weight more effectively than those who had gastric BTX-A injection (P < 0.001). In the gastric BXT-A injection group, the first 3-month delta EBWL and TBWL (change of EBWL and TBWL percentages) were found significantly higher than the 3–6^th month and 6–12^th month (P = 0.001 and P < 0.001).

Conclusion:

Gastric BTX-A injection is a minimally invasive and short-term effective method that can be used in the treatment of obesity.

Evaluation of endoscopic ultrasound-guided gastric botulinum toxin injections in the treatment of obesity

Background

Obesity is rapidly emerging as one of the greatest challenges of human health. Many randomized trials and open-label human studies described conflicting results of gastric intra-muscular injections of botulinum toxin type A (BTA). Endoscopic ultrasound (EUS) guidance can assure BTA injection into the subserosal layer and muscularis propria of the gastric wall which may optimize the efficacy of injection. The aim of the study is to assess the efficacy and safety of EUS-guided gastric BTA injections in weight reduction for obese subjects.

Results

The present study included 25 patients (2 males and 23 females with mean age 35.84 ± 7.776). For nutrient drink tests, median maximum tolerated volumes (MTVs) decreased from 720 cc (range 480–1680) as a baseline value 2 weeks before BTA injection to 360 cc (range 140–820) at 16 weeks after injection. Mean body weight reduction was 11.92 kg (10.8%) after 16 weeks of BTA injection. Mean body weight continued to decrease during the study period from a baseline value of 110 to 98 kg with significant reduction of mean BMI from baseline value of 41.2 to 36.7 at 16 weeks after BTA injection (p < 0.001). The study was completed without major adverse events.

Conclusion

EUS-guided BTA injection into the antral subserosa and muscularis propria could be an effective technique for weight reduction, or as a bridge for surgery, which can be done safely with minimal complications.

Trial registration

NCT03901040

Efficacy of Intragastric Balloon Placement and Botulinum Toxin Injection in Bariatric Endoscopy

BACKGROUND

To evaluate the results obtained from the combination of intragastric botulinum toxin A (IGBTA), intragastric balloon (IGB), and IGBTA(+)IGB in the treatment of obesity.

MATERIALS AND METHODS

Three separate treatment groups were set up. IGBTA, IGB, and IGBTA(+)IGB were administered to Group 1, 2, and 3, respectively. The body mass indexes (BMI) of patients were measured before and 6 months after the treatment. The intragroup and intergroup treatment results have been evaluated. P<0.05 was considered significant.

RESULTS

The mean BMI decreased by 1.6 kg/m in 40 patients who received IGBTA in group 1 (P<0.001), 3.95 kg/m in 42 patients who received IGB in group 2 (P<0.001), and 4.9 kg/m in 39 patients who received IGBTA and IGB in group 3 (P<0.001) after 6 months of treatment. The intolerance because of the application was the highest in group 3, followed by group 2.

CONCLUSION

The treatment was most successful in group 3 followed by group 2 and group 1, respectively. The authors recommend the group 3 treatment, provided that nausea, vomiting, and flatulence have a high index of probability in such a treatment. However, when deciding between group 1 and group 2 treatments, the authors recommend opting for group 2 treatment that shows to be more efficient.

The Positive Effects of a Calorie-Restricting High-Protein Diet Combined with Intragastric Botulinum Toxin Type A Application Among Morbidly Obese Patients: A Prospective, Observational Analysis of Eighty-Seven Grade 2 Obese Patients

PURPOSE

Many studies evaluating the effect of intragastric botulinum toxin type A injection (IG-BTxA) for the treatment of obesity have been published. However, none of these studies combined this procedure with a calorie-restricting high-protein diet. Herein, we aimed to evaluate the effects of IG-BTxA application combined with a calorie-restricting high-protein diet.

MATERIALS AND METHODS

This prospective cohort study is conducted with eighty-seven grade 2 obese patients treated between January 2019 and August 2019. Group 1: IG-BTxA + refused to consult the dietitian; group 2: IG-BTxA + get calorie-restricting high-protein diet; group 3: only get a calorie-restricting high-protein diet. Loss of weight, treatment adaptation (visual analog scale score), the status and changes of comorbid conditions, and changes in eating behaviors (Self-Regulation of Eating Behaviour Questionnaire score) were assessed.

RESULTS

Loss of weight, treatment adaptation, and positive behavioral change in eating preferences were significantly higher in group 2 (p = 0.01; p = 0.001; p < 0.01, respectively). Additionally, the decrease in medication requirement for diabetes and hypertension was higher in group 2 (p < 0.05).

CONCLUSION

IG-BTxA application before calorie-restricting high-protein diet facilitates adaptation to the new diet style and helps to lose weight faster in grade 2 obese patients. Also, more positive results were achieved in terms of controlling comorbid diseases.

Changes in Time of Gastric Emptying After Surgical and Endoscopic Bariatrics and Weight Loss: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Gastric emptying (GE) is involved in the regulation of appetite. We compared times of GE after different bariatric endoscopic and surgical interventions and associations with weight loss.

METHODS

We performed a comprehensive search of publication databases, through September 14, 2018, for randomized and nonrandomized studies reporting outcomes of weight-loss surgeries. Two independent reviewers selected and appraised studies. The outcome of interest was GE T1/2 (min), measured before and after the procedure. A random-effects model was used to pool the mean change in T1/2 (min) after the intervention. We performed a meta-regression analysis to find associations between GE and weight loss. Heterogeneity was calculated using the I2 statistic. Methodologic quality was assessed.

RESULTS

From 762 citations, the following studies were included in our analysis: 9 sleeve gastrectomies, 5 intragastric balloons, and 5 antral botulinum toxins. After sleeve gastrectomy, the pooled mean reduction in GE T1/2 at 3 months was 29.2 minutes (95% CI, 40.9-17.5 min; I2 = 91%). Fluid-filled balloons increased GE T1/2 by 116 minutes (95% CI, 29.4-203.4 min; I2 = 58.6%). Air-filled balloons did not produce a statistically significant difference in GE T1/2. Antral botulinum injections increased GE T1/2 by 9.6 minutes (95% CI, 2.8-16.4 min; I2 = 13.3%). Placebo interventions reduced GE T1/2 by 6.3 minutes (95% CI, 10-2.6 min). Changes in GE were associated with weight loss after sleeve gastrectomy and intragastric balloons, but not botulinum toxin injections.

CONCLUSIONS

In a systematic review and meta-analysis, we found that sleeve gastrectomy reduced GE T1/2 whereas fluid-filled balloons significantly increased GE T1/2. Air-filled balloons do not significantly change the time of GE, which could account for their low efficacy. Antral botulinum toxin injections produced small temporary increases in GE time, which were not associated with weight loss. Changes in GE time after surgical and endoscopic bariatric interventions correlated with weight loss and might be used to select interventions, based on patients' physiology.

Spanish consensus document on bariatric endoscopy. Part 2: specific endoscopic treatments

During the last years we have been witnessing a significant increase in the number and type of bariatric endoscopic techniques: we have different types of balloons, suture systems, injection of substances and malabsorptive prosthesis, etc. Also, some endoscopic revisional procedures for patients with weight regain after bariatric surgery have been incorporated. This makes it necessary to protocolize, position and regularize all these techniques, through a consensus that allows their clinical application with the maximum medical rigor and scientific evidence available.

Devices and Endoscopic Bariatric Therapies for Obesity

PURPOSE OF REVIEW

In this review, we describe the FDA-approved and investigational devices and endoscopic bariatric therapies for the treatment of obesity. We focus on literature published in the past few years and present mechanisms of action as well as efficacy and safety data.

RECENT FINDINGS

Devices and endoscopic procedures are emerging options to fill the significant treatment gap in the management of obesity. Not only are these devices and procedures minimally invasive and reversible, but they are potentially more effective than antiobesity medications, often safer for poor surgical candidates and possibly less expensive than bariatric surgery. As many patients require a variety of management strategies (medications, devices, procedures, and/or surgery) in addition to lifestyle modifications to achieve clinically significant weight loss, the future of obesity treatment involves a multidisciplinary approach. Combinations of advanced treatment strategies can lead to additive or synergistic weight loss. This is an area that requires further investigation.

Obesity Treatment with Botulinum Toxin-A Is Not Effective: a Systematic Review and Meta-Analysis

The effectiveness of gastric injections of botulinum toxin-A (BTA) as primary treatment for obesity is not well known since results in literature are discrepant. Hence, we aimed to systematically review and meta-analyze the available data to assess the real effect of BTA therapy. We searched MEDLINE, Embase, Cochrane, SCOPUS, EBSCO, LILACS, and BVS. We considered eligible only randomized controlled trials enrolling obese patients comparing BTA versus saline injections. Our initial search identified 8811 records. Six studies fulfilled eligibility criteria. After critical appraisal, two articles were excluded and we meta-analyzed the remainder. The mean difference for absolute weight loss and BMI reduction were 0.12 [CI 95%, - 1.14, 1.38] and - 0.06 [95% CI, - 0.92, 0.81], respectively. Therefore, we concluded that treatment of obesity with BTA is not effective.

The Role of Endoscopic Intra-Gastric Botulinum Toxin-A for Obesity Treatment

Obesity prevalence has been increasing with devastating health and economic consequences. Botulinum toxin type A (BTX-A), a neurotoxin, is used clinically for conditions characterized by prolonged muscular contraction. Its inhibitory effects on gastric smooth muscles, in theory, make it a potential agent for obesity treatment through delayed gastric emptying and increased satiety. This review aims to examine the evidence for the use of endoscopic BTX-A injection for treating obesity. The literature search identified 60 articles with 11 primary studies as relevant for the scope of the review. Several studies have been conducted to examine the effect of BTX-A injections on obesity, including both animal and human studies. Current evidence from identified studies does not demonstrate sustained weight loss through the use of endoscopic BTX-A injection.

The Effect of Intragastric Administration of Botulinum Toxin Type A on Reducing Adiposity in a Rat Model of Obesity Using Micro-CT and Histological Examinations

Background/Aims

Botulinum toxin type A (BTX), a long-acting inhibitor of muscular contraction in both striated and smooth muscles, is responsible for gastric motility. The aim of this study was to investigate the effects of an endoscopic intragastric BTX injection on weight loss, body fat accumulation, and gastric emptying time.

Methods

The BTX group consisted of 15 obese rats in which 20 U of BTX were injected into the gastric antrum. The saline group consisted of 15 obese rats injected with 20 U of saline, and the control group included 10 obese rats that did not receive a surgical intervention. The gastric emptying time, biochemical parameters, and body fat volume were evaluated using micro-computed tomography (micro-CT) and histologic evaluations.

Results

The postoperative body weight of the BTX group was significantly lower than those of the other groups (p<0.001) at 6 weeks after the operation. The gastric emptying time (156±54 minutes) was significantly delayed in the BTX group. The BTX group showed significantly lower lipid levels than the other groups. A reduction in body fat volume was observed in the BTX group using micro-CT and histological evaluations.

Conclusions

BTX application to the gastric antrum represents a potentially effective treatment for obesity and may help improve the lipid profile by increasing the gastric emptying time.

Endoluminal weight loss and metabolic therapies: current and future techniques

Obesity is a public health epidemic associated with a number of comorbidities, most notably type 2 diabetes and hypertension, as well as elevated all-cause mortality. The treatment for obesity and its associated comorbidities has most recently expanded into the field of bariatric endoscopy. This field bridges a gap between lifestyle counseling with or without pharmaceutical treatment and the most effective treatment of obesity, bariatric surgery. Because of its minimally invasive nature, bariatric endoscopic therapy has the potential to appeal to the large sector of the obese population that resists surgery, as well as those early in the onset of obesity. To date, five endoscopic devices have been approved by the U.S. Food and Drug Administration for the treatment of obesity, and many more are in development, undergoing clinical trials, or being used around the world. Here, we present the current state of the field, highlight recent developments, and describe the clinical outcomes of these minimally invasive procedures in terms of weight loss, improvement in metabolic profile, and reduction in comorbidities.

Selected Endoscopic Gastric Devices for Obesity

This article focuses on the stomach target devices that are currently in various stages of development. Approved intragastric balloons, devices targeting small bowel and aspiration techniques, are described in other contributions to this issue. Bariatric endoscopic devices targeting the stomach directly alter gastric physiology and promote weight loss by potentially changing functional gastric volume, gastric emptying, gastric wall compliance, neurohormonal signaling, and, thereby, satiety. Many stomach-targeting devices are on the horizon for clinical use, and further study will determine the safety and efficacy for clinical use.

Botulinum Toxin A for Controlling Obesity

Rapid growth of the overweight population and the number of obese individuals in recent decades suggests that current strategies based on diet, exercise, and pharmacological knowledge are not sufficient to address this epidemic. Obesity is the result of a high caloric intake and energy storage, not counterbalanced by an equally important energy expense. Botulinum toxin type A (BoNT-A) use is rapidly expanding to include treatment of a variety of ophthalmological, gastrointestinal, urological, orthopedic, dermatological, secretory, painful, and cosmetic disorders. Many studies evaluating the effect of BoNT-A in gastric antrum e/o fundus for the treatment of obesity have been published. This treatment modality was based on the observation that gastric injection of BoNT-A in laparatomized rats induced a significant reduction of food intake and body weight. These studies have been published yielding debated results. Differences in the selection of patients, the doses of BoNT-A, the method of administration of the toxin, and the instruments of evaluation of some parameters among these studies may be the cause. In this review, it will study the state-of-the-art use of BoNT-A in obesity basic science models and review the clinical evidence on the therapeutic applications of BoNT-A for obesity.

Advances in the Endoscopic Management of Obesity

Obesity has become a worldwide epidemic with significant impact on quality of life, morbidity, and mortality rates. Over the past two decades, bariatric surgery has established itself as the most effective and durable treatment for patients with obesity and its associated comorbidities. However, despite the use of minimally invasive techniques, bariatric surgery is associated with complications in approximately 15% of patients, has a substantial cost, and is used by only 1% of patients who are eligible. Therefore, there is a need for effective minimally invasive therapies, which will be utilized by the large proportion of obese patients who are in desperate need of treatment but are not receiving any. Endoscopic approaches to the management of obesity have been developed, with the aim of delivering more effective, durable, and safer methods of weight reduction. In this paper, we review currently available and future endoscopic therapies that will likely join the armamentarium used in the management of obesity.

Development of minimally invasive techniques for management of medically-complicated obesity

The field of bariatric surgery has been rapidly growing and evolving over the past several decades. During the period that obesity has become a worldwide epidemic, new interventions have been developed to combat this complex disorder. The development of new laparoscopic and minimally invasive treatments for medically-complicated obesity has made it essential that gastrointestinal physicians obtain a thorough understanding of past developments and possible future directions in bariatrics. New laparoscopic advancements provide patients and practitioners with a variety of options that have an improved safety profile and better efficacy without open, invasive surgery. The mechanisms of weight loss after bariatric surgery are complex and may in part be related to altered release of regulatory peptide hormones from the gut. Endoscopic techniques designed to mimic the effects of bariatric surgery and endolumenal interventions performed entirely through the gastrointestinal tract offer potential advantages. Several of these new techniques have demonstrated promising, preliminary results. We outline herein historical and current trends in the development of bariatric surgery and its transition to safer and more minimally invasive procedures designed to induce weight loss.

Gastric antral injections of botulinum toxin delay gastric emptying but do not reduce body weight

BACKGROUND & AIMS

Gastric injections of botulinum toxin A (BTA) have been reported to delay gastric emptying, increase satiation, and reduce body weight, but there are few data from randomized, placebo-controlled studies.

METHODS

We enrolled 60 obese participants in a 24-week, double-blind, randomized, placebo-controlled, concealed allocation trial to compare the effects of gastric antral injections of BTA (100, 300, or 500 U) and saline placebo. The study was conducted at an outpatient clinical research unit. Participants were given one set of injections of BTA or placebo into the gastric antral muscularis propria by using endoscopic ultrasound guidance. Gastric emptying of solids was measured by scintigraphy; we also measured body weight, satiation (maximum tolerated volume in a caloric liquid drink test), calorie intake (by food frequency questionnaire), gastrointestinal symptoms, and psychological aspects of eating behavior (by rating scale).

RESULTS

Compared with baseline values, 2 weeks after injections, the mean half-time for gastric emptying of solids increased by 0.8, 14, 24, and 14 minutes among subjects given placebo, 100, 300, or 500 U BTA, respectively (P = .24 overall, P = .04 for the group given 300 U vs placebo); 16 weeks after the injections, mean body weights were reduced by 2.2, 0.2, 2.3, and 3.0 kg in these groups, respectively. There were no statistically significant differences in mean body weight change, satiation volume, caloric intake, gastrointestinal symptoms, or psychological aspects of eating behavior among groups.

CONCLUSIONS

Gastric antral injections of BTA may delay gastric emptying at a dose of 300 U but do not cause early satiety, altered eating behaviors, or loss of body weight. Clinicaltrials.gov identifier: NCT00976443.

Endoscopic treatment of obesity

BACKGROUND

The increasing incidence of obesity and overweight among children and adolescents will be reflected by the imminent increase in the number of obese patients who require more definitive methods of treatment. There is great interest in new, safe, simple, nonsurgical procedures for weight loss.

OBJECTIVE

To provide an overview of new endoscopic methods for the treatment of obesity.

METHODS

An English-language literature search on endoscopic interventions, endoscopically placed devices and patient safety was performed in the MEDLINE and Cochrane Library databases.

RESULTS

The literature search yielded the following weight loss methods: space-occupying devices (widely used), gastric capacity reduction, modifying gastric motor function and malabsorptive procedures. A commercially available intragastric balloon was the most commonly used device for weight loss. In specific subgroups of patients, it improved quality of life, decreased comorbidities and served as a bridge to surgery. More evidence regarding the potential benefits and safety of other commercially available intragastric balloons is needed to clarify whether they are superior to the most commonly used one. Moreover, early experiences with transoral gastroplasty, the duodenal-jejunal bypass sleeve and an adjustable, totally implantable intragastric prosthesis, indicate that they may be viable options for obesity treatment. Other agents, such as botulinum toxin and a device known as the 'butterfly', are currently at the experimental stage.

CONCLUSION

New endoscopic methods for weight loss may be valuable in the treatment of obesity; however, more clinical experience and technical improvements are necessary before implementing their widespread use.

An update on less invasive and endoscopic techniques mimicking the effect of bariatric surgery

Obesity (BMI 30-35 kg/m(2)) and its associated disorders such as type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular disease have reached pandemic proportions worldwide. For the morbidly obese population (BMI 35-50 kg/m(2)), bariatric surgery has proven to be the most effective treatment to achieve significant and sustained weight loss, with concomitant positive effects on the metabolic syndrome. However, only a minor percentage of eligible candidates are treated by means of bariatric surgery. In addition, the expanding obesity epidemic consists mostly of relatively less obese patients who are not (yet) eligible for bariatric surgery. Hence, less invasive techniques and devices are rapidly being developed. These novel entities mimic several aspects of bariatric surgery either by gastric restriction (gastric balloons, gastric plication), by influencing gastric function (gastric botulinum injections, gastric pacing, and vagal nerve stimulation), or by partial exclusion of the small intestine (duodenal-jejunal sleeve). In the last decade, several novel less invasive techniques have been introduced and some have been abandoned again. The aim of this paper is to discuss the safety, efficacy, complications, reversibility, and long-term results of these latest developments in the treatment of obesity.

Botulinum neurotoxin-A does not spread to distant muscles after intragastric injection: A double-blind single-fiber electromyography study

The purpose of this study was to perform a careful neurophysiological examination to identify subclinical signs of botulinum toxin spread distant to the injection site following intragastric injection for obesity treatment. Single-fiber electromyography of extensor digitorum communis and repetitive stimulation of abductor digiti minimi were performed before and 8 days after multiple intragastric injections of botulinum toxin A (Botox, 200 U per patient) or placebo. The study was performed in a randomized double-blind fashion. No patient in either group displayed results indicative of neuromuscular dysfunction either before or after the treatment. No significant change in muscle jitter was observed when comparing baseline with the after-treatment evaluation in either group, and no significant differences between groups were observed. After intragastric botulinum toxin injection no subclinical sign of distant spread was observed.

Scintigraphic evaluation of gastric emptying in obese patients submitted to sleeve gastrectomy compared to normal subjects

BACKGROUND

Sleeve gastrectomy (SG) has been accepted as an option for surgical treatment for obesity. This operation could be associated with motor gastric dysfunction and abnormal gastric emptying. The purpose of this prospective study is to present the results of gastric emptying to liquids and solids using scintigraphy in patients who underwent SG compared to normal subjects.

METHODS

Twenty obese patients were submitted to laparoscopic SG and were compared to 18 normal subjects. Gastric emptying of liquids and solids was measured by scintigraphic technique. Results were expressed as half time of gastric emptying and the percentage of retention at 20, 30, and 60 min for liquids and at 60, 90, and 120 min for solids.

RESULTS

In the group of operated patients, 70% of them (n = 14) presented accelerated emptying for liquids and 75% (n = 15) for solids compared to 22.2% and 27.7%, respectively, in the control group. The half time of gastric emptying (T (1/2)) in patients submitted to SG both for liquids and solids were significantly more accelerated compared to the control group (34.9 +/- 24.6 vs 13.6 +/- 11.9 min for liquids and 78 +/- 15.01 vs 38.3 +/- 18.77 min for solids; p < 0.01). The gastric emptying for liquids expressed as the percentage of retention at 20, 30, and 60 min was 30.0 +/- 0.25%, 15.4 +/- 0.18%, and 5.7 +/- 0.10%, respectively, in operated patients, significantly less than the control subjects (p < 0.001). For solids, the percentage of retention at 60, 90, and 120 min was 56 +/- 28%, 34 +/- 22%, and 12 +/- 8%, respectively, for controls, while it was 25.3 +/- 0.20%, 9 +/- 0.12%, and 3 +/- 0.05%, respectively, in operated patients (p < 001).

CONCLUSIONS

Gastric emptying after SG is accelerated either for liquids as well as for solids in the majority of patients. These results could be taken in consideration for the dietary indications after surgery and could play a significant role in the definitive results during the late follow-up.

Endoscopic interventions for weight loss surgery

In this paper we review the state-of-the-art in endoscopic interventions for obesity treatment and make best practice recommendations for weight loss surgery (WLS). We performed a systematic search of English-language literature published between April 2004 and June 2008 in MEDLINE and the Cochrane Library on WLS and endoscopic interventions, endoscopically placed devices, minimally invasive surgery, image-guided surgery, endoluminal surgery, endoscopic instrumentation, interventional gastroenterology, transluminal surgery, and natural orifice transluminal surgery. We also searched the literature on endoscopic interventions and WLS and patient safety. We identified 36 pertinent articles, all of which were reviewed in detail; assessed the current science in endoscopic interventions for WLS; and made best practice recommendations based on the latest available evidence. Our findings indicate that endoscopic interventions and endoscopically placed devices may provide valuable approaches to the management of WLS complications and the primary management of obesity. Given the rapid changes in endoscopic technologies and techniques, systematic literature review is required to address issues related to the emerging role of endoluminal surgery in the treatment of obesity. These interventions should be a high priority for development and investigation.

Effects of intramural administration of Botulinum Toxin A on gastric emptying and eating capacity in obese patients

BACKGROUND

Intraparietal gastric administration of Botulinum Toxin A has been studied in open trials to induce satiety and increase weight loss of obese patients with contradictory results. In previous studies only the antrum was the target for Botulinum Toxin A, whereas the fundus, which exerts important activity on gastric accommodation, was excluded. In this study we report the effects of injection into both gastric regions on solid gastric capacity and emptying of the stomach.

MATERIALS AND METHODS

In this study we extended our previous investigations to include 30 obese patients who received Botulinum Toxin A (120 U into the antrum and 80 U into the fundus) or saline by intraparietal endoscopic injection. The two groups were homogeneous for age, gender, body weight and body mass index. Body weight and body mass index, solid gastric emptying (T(1/2) and T(lag) at the octanoic acid breath test) and maximal gastric capacity for solids (kcal) were determined before injection and 2 months later. The results were expressed as mean values (S.E.M.). t-Test or Wilcoxon test was used for statistical analysis, p<0.05 being considered significant.

RESULTS

Both treatments induced a significant reduction of body weight and body mass index but Botulinum Toxin A exerted a significantly greater effect (body weight -11.8+/-0.9 kg vs. -5.5+/-1.1 kg, p<0.0002; body mass index -4.1+/-0.2 vs. -2.2+/-0.4, p<0.001). The maximal gastric capacity for solids was also reduced by both Botulinum Toxin A and placebo, the former being significantly more effective (679+/-114 kcal vs. 237+/-94 kcal, p<0.008). Botulinum Toxin A also significantly increased T(1/2) from 83.4+/-3.9 to 101.6+/-9.9 min, p<0.03) but T(lag) was unchanged. Placebo had no effect on either of these parameters.

CONCLUSIONS

Our results demonstrated that Botulinum Toxin A makes weight loss easier in obese patients. It acts by increasing the solid gastric emptying time and reducing the solid eating capacity of the stomach.

Intragastric injection of botulinum toxin for the treatment of obesity. Where are we?

Obesity has reached epidemic proportions particularly in western countries. Most non-surgical treatments of this condition are disappointing. Since 2005, several studies evaluating the effect of Botulinum Toxin type A (BT-A) in gastric antrum by means of endoscopy for the treatment of obesity have been published. This treatment modality was based on the observation that gastric injection of BT-A in laparatomized rats induced a significant reduction of food intake and body weight. Nowadays, 6 studies have been published yielding conflicting results. Differences in selection of patients, doses of BT-A, method of administration of the toxin and instruments of evaluation of some parameters among these studies may be the cause of divergent results. We discuss herein some important features of these studies pointing out on differences among them. At the same time, based on the knowledge of physiological characteristics of normal and abnormal gastric function related with feeding, we discuss the probable causes of failure observed in these trials. Finally, we give some guidelines concerning the way that future research in this field may follow, not without calling attention to disadvantages of this treatment.

Endoscopic ultrasound-guided gastric botulinum toxin injections in obese subjects: a pilot study

BACKGROUND

Gastric injections of botulinum toxin A (BTA) may induce changes in gastric emptying and body weight, but results vary. BTA dose and depth of injection may affect efficacy. This study assessed changes in gastric emptying, satiation, symptoms, and body weight after endoscopic ultrasound (EUS)-guided injection of 100 or 300 U BTA into gastric antral muscularis propria of obese subjects.

METHODS

Open label study of ten healthy, obese adults (age = 29-49 years, body mass index = 31-54 kg/m(2)) who received 100 U (n = 4) or 300 U (n = 6) BTA and were followed for 16 weeks. Measures included gastric emptying of solids (by scintigraphy), satiation (by maximum tolerated volume [MTV] during nutrient drink test), gastrointestinal symptoms (by the Gastrointestinal Symptom Rating Scale), caloric intake (by food frequency questionnaire), and body weight.

RESULTS

For the entire cohort, MTV decreased from 1,380 cc (range: 474-2,014) at baseline to 620 cc (range: 256-1,180) 2 weeks after BTA injection; decreases were statistically significant in the subjects receiving 300 U BTA (p = 0.03). Average body weight loss was 4.9 (+/-6.3) kg after 16 weeks. Gastric emptying T(1/2) was prolonged in the 300 U BTA group, but not significantly different from baseline (p = 0.17). BTA injections were well tolerated without significant adverse effects.

CONCLUSION

EUS-guided injection of BTA into gastric muscularis propria can be performed safely with minimal adverse effects. A dose of 300 U BTA significantly enhances satiation, is associated with weight loss, and may slow gastric emptying. Further study of higher dose BTA in obese subjects is warranted.

Botulinum toxin: description of injection techniques and examination of controversies surrounding toxin diffusion

The benefits derived from botulinum toxin (BTX) injections may be negated by unintentional weakness of adjacent uninjected muscles. Such weakness may be the result of inaccurate targeting, or diffusion of BTX to surrounding muscles. Several techniques, using electromyographic, endoscopic or imaging guidance are purported to increase the accuracy of targeting. Diffusion of BTX is thought to be influenced by factors such as dose, concentration, injectate volume, number of injections, site and rate of injection, needle gauge, muscle size, muscular fascia, distance of needle tip from the neuromuscular junction, and protein content of the BTX formulation. This article describes techniques that aim to increase the accuracy of BTX injections and examines the controversies surrounding diffusion of BTX following injection.

Intragastric injection of botulinum toxin A for the treatment of obesity

BACKGROUND

Botulinum toxin A (BTX-A) is a powerful and long-acting inhibitor of muscular contractions in both striated and smooth muscles. Hypothetically, BTX-A should inhibit the acetylcholine-mediated peristalsis, which is mainly responsible for gastric motility, and thereby induce slowed gastric emptying, earlier satiety and weight loss. The aim of this study was to observe the effects of endoscopic intragastric injections of BTX-A in obese patients.

METHODS

After approval by the University Ethics Committee, 10 female patients with class I obesity (body mass index 30-35) were double-blind randomized into 2 groups (BTX-A and 0.9% Saline). In Group 1, 200 U BTX-A were injected endoscopically into the antrum and the distal gastric body. In Group 2, 0.9% saline was injected endoscopically into the antrum and the distal gastric body. Body weight and feeling of satiety were recorded monthly over a period of 6 months.

RESULTS

Both groups (BTX-A and 0.9% Saline) showed no significant weight reduction (P>0.05). One patient in Group 1 and two patients in Group 2 reported a feeling of early satiety. No adverse effects related to BTX-A or complications resulting from the endoscopic procedure were observed.

CONCLUSION

Intragastric injection of BTX-A for the treatment of obesity does not seem to reduce body weight.

Gastric motility

PURPOSE OF REVIEW

This review focuses on progress made in the field of gastric motility in the past year, emphasizing advances in understanding the motor physiology of the stomach in health and disease; noninvasive imaging technology and data on novel pharmacotherapeutics and other therapeutic interventions for gastroparesis.

RECENT FINDINGS

The differential conduction pattern in the interstitial cell of Cajal is responsible for the generation of the full spatio-temporal pattern of gastric peristalsis. The mitochondrial powerhouse provides the driving potential for the gastric slow waves. Females are more dependent on the nitrenergic system for gastric relaxation, which is predominantly affected in diabetes. The noninvasive modalities to evaluate gastric function have undergone substantial evolution in the past year. On the therapeutic front, a new generation of medications has been tested and holds promise for the near future. Gastric electrical stimulation is a viable option for medically refractory gastroparesis.

SUMMARY

Using dynamic imaging modalities, the pathophysiology of dyspepsia is becoming better understood and recognized as an end point of multifactorial dysfunction of the enteric neural circuitry. Mechanism-targeted drugs, stem cell transplantation and electrical stimulation options are becoming available.

Gastric emptying of solids and semi-solids in morbidly obese and non-obese subjects: an assessment using the 13C-octanoic acid and 13C-acetic acid breath tests

BACKGROUND

It has been suggested that obesity is associated with an altered rate of gastric emptying. The objective of the present study was to determine whether the rates of solid and semi-solid gastric emptying differ between morbidly obese patients and lean subjects.

METHODS

The Gastric-emptying time (GET) of solid and semi-solid meals were compared between lean healthy subjects and morbidly obese patients enrolled in two previously published studies. GET of solid and semi-solid meals was measured using the 13C-octanoic acid breath test and 13C-acetic acid breath test, respectively, in 24 lean and 14 morbidly obese individuals of both sexes. Student t-test was used to compare the mean data between the lean and morbidly obese groups. The influence of sex, gender, BMI and morbid obesity on the GET of solid meals was verified by linear regression analysis.

RESULTS

Mean t(1/2) values of solid GET (+/- standard deviation) were 203.6 +/- 76.0 min and 143.5 +/- 19.1 min for lean and obese subjects, respectively (P = 0.0010). Mean t(lag) values of solid GET were 127.3 +/- 42.7 min and 98.4 +/- 13.0 min for lean and obese subjects, respectively (P = -0.0044). No significant difference in semi-solid GET was observed between the lean and morbidly obese groups.

CONCLUSION

The present study demonstrated a significantly enhanced gastric emptying of the solid meal test in morbidly obese patients when compared to lean subjects. This finding is compatible with the hypothesis that rapid gastric emptying in morbidly obese subjects increases caloric intake due to a more rapid loss of satiety.