Bariatric embolization: a new and effective option for the obese patient?

Bariatric arterial embolization slows gastric emptying and improves postprandial glycaemia in obese dogs with impaired glucose tolerance

AIM

To evaluate the effects of bariatric arterial embolization (BAE) on gastric emptying of, and the glycaemic response to, an oral glucose load in an obese canine model with impaired glucose tolerance.

METHODS

Eleven male dogs were fed a high-fat, high-fructose diet for 7 weeks before receiving BAE, which involved selective embolization of the left gastric artery (n = 5; 14.9 ± 0.8 kg), or the sham (n = 6; 12.6 ± 0.8 kg) procedure. Postprocedural body weight was measured weekly for 4 weeks. Prior to and at 4 weeks postprocedure, a glucose solution containing 13C-acetate was administered orally for evaluation of the gastric half-emptying time (T50) and the glycaemic response. The relationship between the changes in the blood glucose area under the curve over the first 60 minutes (AUC0-60min) and the T50 was also assessed.

RESULTS

At 4 weeks postprocedure, BAE reduced body weight (BAE vs. the sham procedure: -5.7% ± 0.9% vs. 3.5% ± 0.9%, P < .001), slowed gastric emptying (T50 at baseline vs. postprocedure: 75.5 ± 2.0 vs. 82.5 ± 1.8 minutes, P = .021 in the BAE group; 73.8 ± 1.8 vs. 74.3 ± 1.9 minutes in the sham group) and lowered the glycaemic response to oral glucose (AUC0-60min at baseline vs. postprocedure: 99.2 ± 13.7 vs. 67.6 ± 9.8 mmol·min/L, P = .043 in the BAE group; 100.2 ± 13.4 vs. 103.9 ± 14.6 mmol·min/L in the sham group). The change in the glucose AUC0-60min correlated inversely with that of the T50 (r = -0.711; P = .014).

CONCLUSIONS

In a canine model with impaired glucose tolerance, BAE, while reducing body weight, slowed gastric emptying and attenuated the glycaemic response to an oral glucose load.

Bariatric Artery Embolization for Obese Patients. An Up-to-Date Review

Overweight and obesity are one of public health's major problems in the world. Conservative treatment with exercise, diet and pharmacotherapy is often ineffective, especially in the long term. Bariatric surgery is the gold standard method for a sustained long-term weight loss. Recently the endovascular technique of bariatric artery embolization (BAE) has been studied as an obesity and overweight treatment, with promising results. The goal of this article is to analyze the rationale behind BAE and to provide an up-to-date analysis of its strengths and limitation in comparison with bariatric surgery as a treatment for obesity.

Weight Loss and Gastrointestinal Hormone Variation Caused by Gastric Artery Embolization: An Updated Analysis Study

OBJECTIVE

Many gastric artery embolizations (GAE) have been performed in recent years. We try to determine whether GAE caused weight loss by decreasing gastrointestinal hormone through the analysis of weight loss and gastrointestinal hormones changes.

METHODS

The PubMed and Medline databases, and the Cochrane Library, were searched using the following keywords. A total of 10 animal trials (n=144), 15 human trials (n=270) were included for analysis. After GAE, we mainly evaluated the changes in body weight loss (BWL) and body mass index (BMI), as well as metabolic indexes, such as blood glucose, lipids, and gastrointestinal hormones levels.

RESULTS

Animal subjects received either chemical or particle embolization, while human subjects only received particle embolization. In animal trials (growing period), the GAE group gained weight significantly slower than the sham-operated group, ghrelin levels decreased. In human trials, GAE brought more weight loss in the early stages, with a trend towards weight recovery after several months that was still lower than baseline levels. Besides weight loss, abnormal metabolic indicators, such as blood glucose and lipids were modified, and the quality of life (QOL) scores of obese patients improved. In addition, weight loss positively correlates with ghrelin.

CONCLUSION

GAE may help people lose weight and become a new minimally invasive and effective surgery for the treatment of modest obesity. Physiologic changes in gastrointestinal tract of gastrointestinal hormones level may be one reason for weight loss in GAE.

Left gastric artery embolization for obesity treatment: a systematic review and meta-analysis of human and animal studies

PURPOSE

The main purpose of this systematic review was to reflect on recent literature on bariatric LGA embolization for obesity treatment and to compare this new procedure in human and animal studies.

METHODS

A systematic search of Scopus, MEDLINE, Web of Science, Embase, and Google Scholar was performed to identify human and animal studies employing bariatric LGA embolization to treat obesity. As well, Cochrane's Q test and the I² statistic were utilized to determine heterogeneity.

RESULTS

Nine human and four animal studies recruiting a total of 118 cases (n = 78 patients and n = 40 animals) were included in analysis. All assessments on body mass index (BMI), weight, and ghrelin levels had been fulfilled based on before-after (human studies) and intervention-control designs (animal studies) using bariatric LGA embolization. The findings suggested that bariatric LGA embolization had significantly decreased BMI (mean difference (MD): - 2.66, 95% confidence interval [CI] - 3.74, - 1.58, P < 0.001) and weight (MD: - 8.69, 95% CI - 10.48, - 6.89, P < 0.001) in humans. Although overall pooled estimate showed no significant changes in ghrelin levels following this procedure (Hedges' g statistic: - 0.91, 95% CI - 1.83, 0.01, P = 0.05) in humans, a significant reduction was observed in animal studies (MD: - 756.56, 95% CI - 1098.79, - 414.33, P < 0.001) along with a significant drop in weight (MD: - 7.64, 95% CI - 13.73, - 1.54, P < 0.001).

CONCLUSION

The present study concluded that ghrelin levels in humans had not been affected, although bariatric LGA embolization might significantly improve BMI and weight.

New technologies and advances in weight loss therapy

Bariatric surgery is the most effective treatment for obesity and its comorbidities but there are barriers that prevent its general acceptance. The growing obesity epidemic has resulted in the need for the creation of new, less invasive treatments, with a wide margin of safety and effectiveness for conditioning weight loss, at least greater than that resulting from treatment based on diet and exercise. Emerging therapies include devices that are endoscopically placed and removed, classified as: space-occupying devices, restrictive or anatomic-remodeling procedures, endoluminal bypass, and duodenal mucosal resurfacing. Percutaneous techniques and less invasive surgeries are also included. In general, results have shown improvement in glucose metabolism in diabetic patients. With respect to weight loss, results do not surpass those of bariatric surgery, but are better than results with conservative treatment (diet and exercise) and have a low rate of adverse events. Clinical use of a new technique should be carried out within a multidisciplinary management program that includes nutritional, psychologic, physical activity, and medical support. It must be understood that novel therapies are not being created to substitute bariatric surgery, but rather to increase treatment options in the general population, with greater reach and impact. The aim of the present study was to provide an up-to-date literature review on emerging technologies for the treatment of obesity.

Bariatric Embolization: A Narrative Review of Clinical Data From Human Trials

Bariatric arterial embolization (BAE) is a novel technique that is investigated as an alternative, often supplementary, method for weight management. BAE reduces blood perfusion to the gastric fundus, and thus, reduces the production of appetite-inducing hormones. No randomized controlled trial has evaluated the efficacy of BAE to date. Available evidence from published studies include retrospective evaluations of patients undergoing left gastric artery embolization for gastrointestinal bleeding, and early prospective, single-arm clinical trials. Review of clinical data from human trials suggest an average weight loss of about 8-9 kg (ranging 7.6-22.0 kg), corresponding to 8-9% (ranging 4.8-17.2%) of the patients' baseline weight. Common complications include superficial gastric ulcers. Though uncommon, gastric perforation and splenic infarct are important major complication that may arise after left gastric artery embolization. Overall, BAE is an effective, relatively safe procedure that may be associated with clinically significant weight loss in patients with obesity.

The GAMMA concept (gastrointestinal activity manipulation to modulate appetite) preliminary proofs of the concept of local vibrational gastric mechanical stimulation

BACKGROUND

Mechanical stimulation of the stretch receptors of the gastric wall can simulate the presence of indigested food leading to reduced food intake. We report the preliminary experimental results of an innovative concept of localized mechanical gastric stimulation.

METHODS

In a first survival study, a biocompatible bulking agent was injected either in the greater curvature (n = 8) or in the cardia wall (n = 8) of Wistar rats. Six animals served as sham. Changes of bulking volume, leptin levels and weight gain were monitored for 3 months. In a second acute study, a micro-motor (n = 10; MM) or a size-paired inactive device (n = 10; ID) where applied on the cardia, while 10 additional rats served as sham. Serum ghrelin and leptin were measured at baseline and every hour (T0-T1-T2-T3), during 3 h. In a third study, 24 implants of various shapes and sizes were introduced into the gastric subserosa of 6 Yucatan pigs. Monthly CT scans and gastroscopies were done for 6 months.

RESULTS

Weight gain in the CW group was significant lower after 2 weeks and 3 months when compared to the shame and GC (p = 0.01/p = 0.01 and p = 0.048/p = 0.038 respectively). Significant lower increase of leptin production occurred at 2 weeks (p = 0.01) and 3 months (p = 0.008) in CW vs. SG. In the MM group significant reduction of the serum ghrelin was seen after 3 h. Leptin was significantly increased in both MM and ID groups after 3 h, while it was significantly reduced in sham rats. The global device retention was 43.5%. Devices with lower profile and with a biocompatible coating remained more likely in place without complications.

CONCLUSIONS

Gastric mechanical stimulation induced a reduced weight gain and hormonal changes. Low profile and coated devices inserted within the gastric wall are more likely to be integrated.

Gastrointestinal Hormones Manipulation to Counteract Metabolic Syndrome Using Duodenal Targeted Embolization

PURPOSE

Targeted embolization of gastrointestinal (GI) arteries can modify hormonal production. We aimed to evaluate the impact of the embolization of the gastroduodenal artery (GDA) on the activity of foregut mucosa.

METHODS

The GDA's duodenal branch was embolized in 12 Yucatan pigs using 100-300 µm (group A; n = 4) or 300-500 µm (group B; n = 4) microspheres, followed by coiling of the branch. In 4 animals (sham), only saline was injected. The levels of GI hormones (ghrelin, glucose-dependent insulinotropic peptide [GIP], glucagon-like peptide-1 [GLP-1], insulin, peptide YY [PYY], leptin) and the gene expression of sodium-glucose-linked transporter-1 (SGLT-1) and glucose transporter-2 (GLUT-2) were assessed before (T0), 1 hour (T1), 1 month (T2), 3 months (T3), and 6 months (T4) after embolization.

RESULTS

In group A, a segmental duodenal stenosis occurred in all cases, which required balloon dilatation. There was a significant drop in the baseline glycemia in group A at T1 and T4 versus sham. Ghrelin was reduced in group A versus baseline and versus group B at T2 and T3 and versus sham at T1 and T3. Insulin was significantly lower in group A versus B at T1 and at T4 but not versus sham. SGLT-1 expression increased in B and sham at T4, while it remained stable in group A. GLUT-2 expression increased in sham at T4 but not in A or B.

CONCLUSIONS

GDA embolization induced a decrease in ghrelin production and influenced expression of glucose carriers in the foregut mucosa.

Bariatric surgery in obese patients reduced resting connectivity of brain regions involved with self-referential processing

Obese individuals exhibit brain alterations of resting-state functional connectivity (RSFC) integrity of resting-state networks (RSNs) related to food intake. Bariatric surgery is currently the most effective treatment for combating morbid obesity. How bariatric surgery influences neurocircuitry is mostly unknown. Functional connectivity density (FCD) mapping was employed to calculate local (lFCD)/global (gFCD) voxelwise connectivity metrics in 22 obese participants who underwent functional magnetic resonance imaging before and 1 month after sleeve gastrectomy (SG), and in 19 obese controls (Ctr) without surgery but tested twice (baseline and 1-month later). Two factor (group, time) repeated measures ANOVA was used to assess main and interaction effects in lFCD/gFCD; regions of interest were identified for subsequent seed to voxel connectivity analyses to assess resting-state functional connectivity and to examine association with weight loss. Bariatric surgery significantly decreased lFCD in VMPFC, posterior cingulate cortex (PCC)/precuneus, and dorsal anterior cingulate cortex (dACC)/dorsomedial prefrontal cortex (DMPFC) and decreased gFCD in VMPFC, right dorsolateral prefrontal cortex (DLPFC) and right insula (p_FWE  < .05). lFCD decreased in VMPFC and PCC/precuneus correlated with reduction in BMI after surgery. Seed to voxel connectivity analyses showed the VMPFC had stronger connectivity with left DLPFC and weaker connectivity with hippocampus/parahippocampus, and PCC/precuneus had stronger connectivity with right caudate and left DLPFC after surgery. Bariatric surgery significantly decreased FCD in regions involved in self-referential processing (VMPFC, DMPFC, dACC, and precuneus), and interoception (insula), and changes in VMPFC/precuneus were associated with reduction in BMI suggesting a role in improving control of eating behaviors following surgery.

Bariatric Surgery and Hypertension

Obesity continues to increase in prevalence worldwide. Hypertension has long been associated with obesity, and weight loss continues to be a first-line therapy in the treatment of hypertension. Lifestyle modification and pharmacologic therapy, however, often meet with treatment failure. Bariatric surgery continues to be the most successful approach to sustained weight loss. This review focuses on the underlying physiologic mechanisms of obesity-hypertension, and the impact of bariatric surgery on the treatment of hypertension. Current available literature on the physiologic mechanisms of obesity-hypertension, and the major trials, meta-analyses and systematic reviews of the impact of bariatric surgery procedures on hypertension are reviewed. Evidence suggests significant improvement in obesity-hypertension in patients who undergo surgical weight-reduction procedures. Malabsorptive techniques such as the Roux-en-Y gastric bypass or surgical resection techniques such as laparoscopic sleeve gastrectomy appear to offer superior results in regards to hypertension control over restrictive techniques such as Gastric Banding. Though long-term control of hypertension following surgery remains a concern, available follow-up post-operative data of up to 10 years suggests a sustained, if lessened, effect on hypertension control over time.