A preliminary observation of weight loss following left gastric artery embolization in humans

Bariatric arterial embolization in patients with body mass index ranging from 25 to 40 kg/m2: A systematic review & meta-analysis

The present review sought to evaluate by meta-analysis the efficacy of bariatric arterial embolization (BAE) in promoting weight loss in patients with body mass index (BMI) ranging from 25-40 kg/m2. This study was performed and reported according to Preferred Reporting Items for Systematic reviews and Meta-analysis guidelines. A systematic literature search of MEDLINE, Embase Google Scholar, and World Health Organization Library database was done for studies evaluating BAE for promoting weight loss in patients with BMI ranging from 25-40 kg/ m2 published up to March 10, 2021. Primary outcome measure included weight loss after the embolisation procedure. Three single-arm studies comprising of a total of 28 patients (BMI: 25- 40 kg/m2) were found eligible for meta-analysis. All patients underwent embolization with either Embosphere microspheres or PVA particles. The predominant artery embolised was left gastric artery (in all patients). Additional arteries embolised included gastroepiploic artery (8 patients), or accessory left gastric artery (1 patient), or short gastric artery (1 patient). Pooled absolute mean weight loss was 7.854 kg (95% CI: 6.103-9.605). No significant statistical heterogeneity was detected (I2=51.75%, P=0.126) among pooled studies. In conclusion, limited single-arm studies report BAE as an effective, and relatively safe procedure for promoting weight loss in patients with BMI ranging from 25-40 kg/m2, although the number of patients included is very small. Initial results of BAE in promoting weight loss are promising with no major/severe complications reported; however, long term follow-up is required to see the sustainability of the effects.

EMBIO trial study protocol: left gastric artery embolisation for weight loss in patients living with obesity with a BMI 35-50 kg/m2

INTRODUCTION

Left gastric artery embolisation (LGAE) is a well-established treatment for major upper gastrointestinal (GI) bleeding when control is not established via upper GI endoscopy and recently has shown promising results for weight loss in small single arm studies. LGAE could be a treatment option in between our current tier-3 and tier-4 services for obesity. EMBIO is a National Institute for Health Research funded trial, a multicentre double-blinded randomised controlled trial between Imperial College National Health Service Trust and University College London Hospital, comparing LGAE versus Placebo procedure. The key aims of the trial is to evaluate LGAE efficacy on weight loss, its mechanism of action, safety profile and obesity-related comorbidities.

METHODS AND ANALYSIS

76 participants will be recruited from the existing tier-3 database after providing informed consent. Key inclusion criteria include adults aged 18-70 with a body mass index 35-50 kg/m2 and appropriate anatomy of the left gastric artery and coeliac plexus on CT Angiogram. Key exclusion criteria included previous major abdominal and bariatric surgery, weight >150 kg, type 2 diabetes on any medications other than metformin and the use of weight modifying medications. Participants will undergo mechanistic visits 1 week prior to the intervention and 3, 6 and 12 months postintervention. Informed consent will be received from each participant and they will be randomised in a 1:1 ratio to left gastric artery embolisation and placebo treatment. Blinding strategies include the use of moderate doses of sedation, visual and auditory isolation. All participants will enter a tier-3 weight management programme postintervention. The primary analysis will estimate the difference between the groups in the mean per cent weight loss at 12 months.

ETHICS AND DISSEMINATION

This trial shall be conducted in full conformity with the 1964 Declaration of Helsinki and all subsequent revisions. Local research ethics approval was granted by London-Central Research Ethics Committee, (Reference 19/LO/0509) on 11 October 2019. The Medicines and Healthcare products Regulatory Agency (MHRA) issued the Letter of No Objection on 8 April 2022 (Reference CI/2022/0008/GB). The trial's development and progress are monitored by an independent trial steering committee and data monitoring and ethics committee. The researchers plan to disseminate results at conferences, in peer- reviewed journals as well as lay media and to patient organisations.

TRIAL REGISTRATION NUMBER

ISRCTN16158402.

Interventional metabology: A review of bariatric arterial embolization and endovascular denervation for treating metabolic disorders

The rising prevalence of metabolic disorders such as obesity and type 2 diabetes mellitus (T2DM) poses a major challenge to global health. Existing therapeutic approaches have limitations, and there is a need for new, safe, and less invasive treatments. Interventional metabolic therapy is a new addition to the treatment arsenal for metabolic disorders. This review focuses on two interventional techniques: bariatric arterial embolization (BAE) and endovascular denervation (EDN). BAE involves embolizing specific arteries feeding ghrelin-producing cells to suppress appetite and promote weight loss. EDN targets nerves that regulate metabolic organs to improve glycemic control in T2DM patients. We describe the current state of these techniques, their mechanisms of action, and the available safety and effectiveness data. We also propose a new territory called "Interventional Metabology" to encompass these and other interventional approaches to treating metabolic disorders.

Nano-embedded medical devices and delivery systems in interventional radiology

Nanomaterials research has significantly accelerated the development of the field of vascular and interventional radiology. The incorporation of nanoparticles with unique and functional properties into medical devices and delivery systems has paved the way for the creation of novel diagnostic and therapeutic procedures for various clinical disorders. In this review, we discuss the advancements in the field of interventional radiology and the role of nanotechnology in maximizing the benefits and mitigating the disadvantages of interventional radiology theranostic procedures. Several nanomaterials have been studied to improve the efficacy of interventional radiology interventions, reduce the complications associated with medical devices, improve the accuracy and efficiency of drug delivery systems, and develop innovative imaging modalities. Here, we summarize the recent progress in the development of medical devices and delivery systems that link nanotechnology in vascular and interventional radiology. This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease.

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.

A Novel approach to catheterizing the Left Gastric Artery for bariatric embolization

We present the case of a 45 Y/o morbidly obese male who - unable to lose weight despite extensive lifestyle interventions, presented to us for an experimental procedure known as bariatric embolization. This arterial embolization procedure was performed targeting the left gastric artery with aims to restrict blood flow to the gastric fundus, and lowering serum ghrelin levels. In this case the left gastric artery arose cephalad from the celiac, earlier than where it normally branches; a variation known as a “false tripod”, causing some initial difficulty with selection. We describe how introducing a tertiary curve on the guidewire proved successful. Adapting the guidewire for difficult anatomy is an often a very underutilized skillset for many interventionalists - but led to success in this rather nascent procedure.

Endovascular Bariatric Surgery as Novel Minimally Invasive Technique for Weight Management in the Morbidly Obese: Review of the Literature

Nowadays, obesity represents one of the most unresolved global pandemics, posing a critical health issue in developed countries. According to the World Health Organization, its prevalence has tripled since 1975, reaching a prevalence of 13% of the world population in 2016. Indeed, as obesity increases worldwide, novel strategies to fight this condition are of the utmost importance to reduce obese-related morbidity and overall mortality related to its complications. Early experimental and initial clinical data have suggested that endovascular bariatric surgery (EBS) may be a promising technique to reduce weight and hormonal imbalance in the obese population. Compared to open bariatric surgery and minimally invasive surgery (MIS), EBS is much less invasive, well tolerated, with a shorter recovery time, and is probably cost-saving. However, there are still several technical aspects to investigate before EBS can be routinely offered to all obese patients. Further prospective studies and eventually a randomized trial comparing open bariatric surgery vs. EBS are needed, powered for clinically relevant outcomes, and with adequate follow-up. Yet, EBS may already appear as an appealing alternative treatment for weight management and cardiovascular prevention in morbidly obese patients at high surgical risk.

Effect of left gastric artery embolization on obesity and ghrelin/leptin levels in pigs

OBJECTIVE

To investigate the influence of left gastric artery embolization (LGAE) on obesity and Ghrelin/Leptin levels in pigs.

METHODS

Healthy female Wuzhishan piglets aged 3-4 months were allocated into obesity + LGAE group, obesity group, control group (fed with a normal diet; n=8 for each group). Body weight, serum Ghrelin, Leptin, glucose and insulin levels were compared before surgery, 1 month and 3 months after surgery.

RESULTS

Piglets in obesity group and obesity + LGAE group were heavier than those in control group before and 1 month after surgery (P<0.001), and in obesity group were heavier than those in obesity + LGAE group 1 month after surgery (P<0.05). A significant decrease in body weight was observed in obesity + LGAE group 3 months after surgery (P<0.05), and the obesity group showed heavier weight than the other two groups (P<0.001). Ghrelin levels in obesity group and obesity + LGAE group were higher than those in control group before and 1 month after surgery (P<0.001), and in obesity group were higher than those in obesity + LGAE group 1 month after surgery (P<0.05). They showed an evident decrease in obesity + LGAE group 3 months after surgery (P<0.05), and in obesity group were higher than that in the other two groups (P<0.01). Leptin levels in obesity group and obesity + LGAE group were higher than those in control group before surgery (P<0.01) and 1 month after surgery (P<0.05). They decreased significantly in obesity + LGAE group 3 months after surgery (P<0.01), and in obesity group were higher than those in the other two groups (P<0.01).

CONCLUSION

LGAE greatly contributes to weight loss possibly by reducing the secretion of Ghrelin and Leptin.

Effect of left or right gastric artery interventional embolization on obesity and ghrelin/leptin expression in pigs

OBJECTIVE

To investigate the effect of left or right gastric artery interventional embolization on obesity and ghrelin/leptin expression in pigs.

METHODS

Thirty-two female Wuzhishan pigs aged 3-4 months were randomly divided into four groups, with eight pigs in each group: obesity + left gastric artery embolization group, obesity + right gastric artery embolization group, obesity + sham surgery group and healthy control group. The body weight and serum levels of ghrelin, leptin, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) before the operation, one month and three months after the operation, and the gastric pathology three months after the operation were compared.

RESULTS

The preoperative body weight, ghrelin level, leptin level, IL-6 level and TNF-α level of the obesity + sham surgery group, obesity + left gastric artery embolization group and obesity + right gastric artery embolization group were higher than those of the healthy control group (all P<0.05). One month after the operation, the body weight, ghrelin level, leptin level, IL-6 level and TNF-α level of the obesity + sham surgery group, obesity + left gastric artery embolization group and obesity + right gastric artery embolization group were higher than those of the healthy control group. The body weight, ghrelin level, IL-6 level and TNF-α level of the obesity + sham surgery group were higher than those of the obesity + left artery embolization group and obesity + right gastric artery embolization group (all P<0.05). Three months after the operation, the body weight, ghrelin level, leptin level, IL-6 level and TNF-α level of the obesity + sham surgery group were higher than those of the obesity + left artery embolization group, obesity + right artery embolization group and the healthy control group (all P<0.05).

CONCLUSION

Left or right gastric artery interventional embolization in pigs can effectively reduce body weight, which may be related to the reduced secretion of ghrelin, leptin and inflammatory factors. However, the clinical application and safety of left or right gastric artery embolization still need further study.

Bariatric Arterial Embolization with Calibrated Radiopaque Microspheres and an Antireflux Catheter Suppresses Weight Gain and Appetite-Stimulating Hormones in Swine

PURPOSE

To examine safety and efficacy of bariatric arterial embolization (BAE) with x-ray-visible embolic microspheres (XEMs) and an antireflux catheter in swine.

MATERIAL AND METHODS

BAE with selective infusion of XEMs (n = 6) or saline (n = 4, control) into gastric fundal arteries was performed under x-ray guidance. Weight and plasma hormone levels were measured at baseline and weekly for 4 weeks after embolization. Cone-beam CT images were acquired immediately after embolization and weekly for 4 weeks. Hormone-expressing cells in the stomach were assessed by immunohistochemical staining.

RESULTS

BAE pigs lost weight 1 week after embolization followed by significantly impaired weight gain relative to control animals (14.3% vs 20.9% at 4 weeks, P = .03). Plasma ghrelin levels were significantly lower in BAE pigs than in control animals (1,221.6 pg/mL vs 1,706.2 pg/mL at 4 weeks, P < .01). XEMs were visible on x-ray and cone-beam CT during embolization, and radiopacity persisted over 4 weeks (165.5 HU at week 1 vs 158.5 HU at week 4, P = .9). Superficial mucosal ulcerations were noted in 1 of 6 BAE animals. Ghrelin-expressing cell counts were significantly lower in the gastric fundus (17.7 vs 36.8, P < .00001) and antrum (24.2 vs 46.3, P < .0001) of BAE pigs compared with control animals. Gastrin-expressing cell counts were markedly reduced in BAE pigs relative to control animals (98.5 vs 127.0, P < .02). Trichrome staining demonstrated significantly more fibrosis in BAE animals compared with control animals (13.8% vs 8.7%, P < .0001).

CONCLUSIONS

XEMs enabled direct visualization of embolic material during and after embolization. BAE with XEMs and antireflux microcatheters was safe and effective.

Gastric artery embolization: studying the effects of catheter type and injection method on microsphere distributions within a benchtop arterial model

Aims

The objective of the study is to investigate the effect of catheter type and injection method on microsphere distributions, specifically vessel targeting accuracy.

Materials and methods

The study utilized three catheter types (a standard end-hole micro-catheter, a Surefire anti-reflux catheter, and an Endobar occlusion balloon catheter) and both manual and computer-controlled injection schemes. A closed-loop, dynamically pressurized surrogate arterial system was assembled to replicate arterial flow for bariatric embolization procedures. Four vessel branches immediately distal to the injection site were targeted for embolization. Embolic microspheres were injected into the model using these  three catheter types and both manual and computer-controlled injections.

Results

Across all injection methods, the catheter effect on the proportion of microspheres to target vessels (vs. non-target vessels) was significant (p = 0.005). The catheter effect on the number of non-target vessels embolized was nearly significant (p = 0.059). Across all catheter types, the injection method effect was not statistically significant for either of two outcome measures (percent microspheres to target vessels: p = 0.265, number of non-target vessels embolized: p = 0.148).

Conclusion

Catheter type had a significant effect on targeting accuracy across all injection methods. The Endobar catheter exhibited a higher targeting accuracy in pairwise comparisons with the other two injection catheters across all injection schemes and when considering the Endobar catheter with the manifold injection method vs. each of the catheters with the manual injection method; the differences were significant in three of four analyses. The injection method effect was not statistically significant across all catheter types and when considering the Endobar catheter/Endobar manifold combination vs. Endobar catheter injections with manual and pressure-replicated methods.

Future of Bariatric Embolization: A Review of Up-to-date Clinical Trials

Obesity is a significant health issue with an overall rise in mortality; it has multiple risk factors, including hormonal effects, which play a significant role in the balance of food intake and weight gain. Ghrelin is an anabolic hormone secreted from stomach fundus and plays a significant role in this regulation. Management of obesity involves multiple interventions, including lifestyle adjustment, pharmacotherapy, and bariatric surgery. Bariatric embolization is a relatively new procedure; several animal studies show that embolization of the left gastric artery reduces serum ghrelin and induces weight loss.  Also, several clinical studies were conducted in the past ten years which have shown bariatric embolization's effectiveness in inducing weight loss: a meta-analysis of 47 patients included in six different clinical studies of left gastric artery embolization resulted in 8% total weight loss from baseline body weight. Many studies also show this procedure's effect on lowering the HgA1C level and lipid profile. Clinical studies mostly reported minor adverse effects such as transient abdominal discomfort, nausea and vomiting, gastric ulcers, and major adverse effects were uncommon, suggesting the procedure is well tolerated. It may be an alternative line of management in patients who are not suitable candidates for bariatric surgery. Although future clinical studies will provide an answer to several questions like the exact effects of the procedure on diabetes and metabolic syndrome, future studies are also needed to establish particular guidelines to match different patient characteristics with their optimal procedural techniques and pre- and post-procedure evaluation tests.

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.

Left Gastric Artery Embolisation for the Treatment of Obesity: a Systematic Review

BACKGROUND

Endovascular left gastric artery (LGA) embolisation has gained significant attention in the treatment of obesity/morbid obesity and reduction of ghrelin. The objective of this systematic review is to evaluate the recent literature, strengths, limitations and practical aspects of this new procedure in combination with its physiological and anatomical paradigm.

METHODS

A systematic electronic search of literature from 1966 to June 2017 in Medline, CINHAL, Embase, Scopus and Cochrane library in English language and adult subjects was conducted. This search was conducted in accordance with Preferred Reporting in Systematic Review and Meta-Analysis (PRISMA) guidelines. Quality assessment of the articles was performed, using Oxford critical appraisal skills programme (CASP), and their recommendation for practice was examined through National Institute for health Care Excellence (NICE). Inter-related reliability (Cronbach's Alpha) was assessed between the two independent reviewers.

RESULTS

A total of n = 62 individuals were subjected to LGA embolisation. At 1-3 months, 7-11% and, at 12 months, 2% weight reduction was associated with ghrelin concentration reduction of 36% at 6 months. There was Haemoglobin A1c reduction (7.4 to 6.3%) and improved quality of life (SF-36 questionnaire) at 6 months (9.5 points) (range, 3.2-17.2). Despite immediate epigastric pain and mucosal ulceration, no long-term adverse outcome was identified. The overall length of stay was 2-3 days.

CONCLUSIONS

The outcome of this review (level of evidence 3) suggests LGA embolisation is feasible and effective and perhaps a safe procedure in the treatment of obesity and reduction of ghrelin. However, further trials are highly advocated.

Medical Devices in Obesity Treatment

PURPOSE OF REVIEW

Obesity is increasing at an alarming rate and now poses a global threat to humankind. In recent years, we have seen the emergence of medical devices to combat the obesity epidemic. These therapeutic strategies are discussed in this review dividing them into gastric and duodenal therapies.

RECENT FINDINGS

Traditionally, medical devices for obesity such as the intragastric balloon have focused on reducing gastric size, but more recently there has been a shift towards developing devices that modulate neural and hormonal responses to induce early satiety thus reducing oral intake. Medical devices for obesity treatment may have a role in those patients who are struggling to control their weight despite significant lifestyle modifications such as diet and exercise and who decline or are unfit for bariatric surgery. For the wider adoption and integration of these devices in the obesity treatment paradigm, more long-term efficacy and safety data from randomised controlled trials are required.

Advances in Biomaterials and Technologies for Vascular Embolization

Minimally invasive transcatheter embolization is a common nonsurgical procedure in interventional radiology used for the deliberate occlusion of blood vessels for the treatment of diseased or injured vasculature. A wide variety of embolic agents including metallic coils, calibrated microspheres, and liquids are available for clinical practice. Additionally, advances in biomaterials, such as shape-memory foams, biodegradable polymers, and in situ gelling solutions have led to the development of novel preclinical embolic agents. The aim here is to provide a comprehensive overview of current and emerging technologies in endovascular embolization with respect to devices, materials, mechanisms, and design guidelines. Limitations and challenges in embolic materials are also discussed to promote advancement in the field.

Body composition changes after left gastric artery embolization in overweight and obese individuals

PURPOSE

To determine the effects of left gastric artery embolization (LGAE) on computed tomography (CT) body composition change.

MATERIALS AND METHODS

Sixteen overweight or obese patients who had abdominal CT scans before and after LGAE for gastric bleeding were retrospectively reviewed. Body composition analysis was performed with semiautomated imaging processing algorithms (MATLAB 13.0, Math Works, MA). Adipose tissue and lean skeletal muscle were measured using threshold attenuation values. Total body fat index (BFI), subcutaneous fat index (SFI), visceral fat index (VFI), intramuscular fat index (IMFI), and skeletal muscle index (SMI) were determined ([tissue area (cm)]²/[height (m)]²). Excess body weight (EBW) was determined based on the Lorentz formula for ideal body weight.

RESULTS

Mean follow-up was 1.5 ± 0.8 months. Following LGAE, patients experienced significantly decreased body weight (p = 0.003), BMI (p = 0.005), EBW (p = 0.003), BFI (p = 0.03), SFI (p = 0.03), and SMI (p < 0.001). Changes in VFI and IMFI did not significantly change (p = 0.13 and p = 0.83, respectively).

CONCLUSIONS

Patients who underwent LGAE had significant unintended weight loss as a result of decreased body fat and skeletal muscle. Body composition analysis can readily assess the extent of fat loss and identify muscle wasting.

Bariatric Embolization of Arteries for the Treatment of Obesity (BEAT Obesity) Trial: Results at 1 Year

Background Bariatric embolization is a new endovascular procedure to treat patients with obesity. However, the safety and efficacy of bariatric embolization are unknown. Purpose To evaluate the safety and efficacy of bariatric embolization in severely obese adults at up to 12 months after the procedure. Materials and Methods For this prospective study (NCT0216512 on ClinicalTrials.gov ), 20 participants (16 women) aged 27-68 years (mean ± standard deviation, 44 years ± 11) with mean body mass index of 45 ± 4.1 were enrolled at two institutions from June 2014 to February 2018. Transarterial embolization of the gastric fundus was performed using 300- to 500-µm embolic microspheres. Primary end points were 30-day adverse events and weight loss at up to 12 months. Secondary end points at up to 12 months included technical feasibility, health-related quality of life (Short Form-36 Health Survey ([SF-36]), impact of weight on quality of life (IWQOL-Lite), and hunger or appetite using a visual assessment scale. Analysis of outcomes was performed by using one-sample t tests and other exploratory statistics. Results Bariatric embolization was performed successfully for all participants with no major adverse events. Eight participants had a total of 11 minor adverse events. Mean excess weight loss was 8.2% (95% confidence interval [CI]: 6.3%, 10%; P < .001) at 1 month, 11.5% (95% CI: 8.7%, 14%; P < .001) at 3 months, 12.8% (95% CI: 8.3%, 17%; P < .001) at 6 months, and 11.5% (95% CI: 6.8%, 16%; P < .001) at 12 months. From baseline to 12 months, mean SF-36 scores increased (mental component summary, from 46 ± 11 to 50 ± 10, P = .44; physical component summary, from 46 ± 8.0 to 50 ± 9.3, P = .15) and mean IWQOL-Lite scores increased from 57 ± 18 to 77 ± 18 (P < .001). Hunger or appetite decreased for 4 weeks after embolization and increased thereafter, without reaching pre-embolization levels. Conclusion Bariatric embolization is well tolerated in severely obese adults, inducing appetite suppression and weight loss for up to 12 months. Published under a CC BY-NC-ND 4.0 license. Online supplemental material is available for this article.

Bariatric Arterial Embolization for Obesity: A Review of Early Clinical Evidence

Obesity is a worldwide public health epidemic that leads to increased morbidity, mortality, and cost burden to health care. Although bariatric surgery has been recognized as a standard invasive treatment for obesity, it is accompanied by relatively high morbidity and cost burden, as well as limited treatment outcome. Therefore, alternative treatments with lower morbidity and cost for surgery that target patients who are obese, but not morbidly obese, are needed. A minimally invasive trans-catheter procedure, named bariatric arterial embolization or bariatric embolization (BAE), has been identified as a potential solution, based on its safety and preliminary efficacy profiles. The purpose of this review is to introduce up-to-date clinical data and discuss future directions for BAE for the treatment of obesity.

Analysis of weight changes after left gastric artery embolization in a cancer-naive population

PURPOSE

We aimed to evaluate weight changes after left gastric artery (LGA) embolization in a retrospective cancer-naive cohort.

METHODS

A retrospective study was conducted to identify patients who underwent LGA embolization for gastrointestinal bleeding (GI). Patients with known cancer diagnoses at the time of LGA embolization were excluded. Pre- and postprocedure weights were assessed. Statistical analysis was performed using paired t-test and Wilcoxon signed-rank test.

RESULTS

A total of 39 patients were identified. In 21 patients who had documented pre- and postprocedural weights, a median of 16.3 kg weight loss (P = 0.045) was observed over a median time of 12 months (range, 2-72). In patients who had pre- and postprocedure endoscopies (n=6), 2 had worsening ulcers following LGA embolization and 4 had stable or no abnormal findings.

CONCLUSION

Our preliminary observation suggests that LGA embolization is well tolerated and results in unintended weight loss. Larger studies are needed to confirm these preliminary findings.

Bariatric Embolization of the Left Gastric Arteries for the Treatment of Obesity: 9-Month Data in 5 Patients

PURPOSE

The purpose of this study is to investigate the safety and 9-month effectiveness of transcatheter left gastric artery embolization (LGAE) for treating patients with obesity.

MATERIALS AND METHODS

The protocol of this study was approved by the Institutional Ethics Review Board. Five obese patients (3 men and 2 women) with mean weight of 102.0 ± 16.19 kg (range, 82.1-125.5 kg) and mean body mass index (BMI) of 38.1 kg/m² ± 3.8 (range, 32.9-42.4 kg/m²) underwent LGAE with polyvinyl alcohol (PVA) particles in diameter of 500-710 μm. The primary endpoint was the safety by grading the adverse events (AEs) according to the Common Terminology Criteria for Adverse Events (CTCAE v4.0) within 30 days after LGAE. The secondary endpoints were measured with serum ghrelin and leptin levels, body weight, waist circumference, waist-to-height ratio, and abdominal fat quantity on MRI at the day immediately before LGAE and every 3 months after LGAE.

RESULTS

LGAE was successfully performed in all patients. A superficial linear ulceration below the cardia was seen in 1 patient 3 days after LGAE and healed within 30 days. No other serious AEs (grade III or above) occurred. Average body weight loss at 3, 6, and 9 months was 8.28 ± 7.3 kg (p = 0.074), 10.42 ± 8.21 kg (p = 0.047), and 12.9 ± 14.66 kg (p = 0.121), respectively. The level of serum ghrelin decreased by 40.83% (p = 0.009), 31.94% (p = 0.107), and 24.82% (p = 0.151) at 3, 6, and 9 months after LGAE, respectively. There was minimal reduction of leptin levels at 3 and 6 months following LGAE (decreased by 0.26%, p = 0.929, and 4.33%, p = 0.427, respectively), but it declined obviously 9 months after LGAE (decreased by 11.22%, p = 0.295). Both waist circumference and waist-to-height ratio decreased after LGAE. MRI showed the area of subcutaneous adipose tissue decreased from the baseline of 400.90 ± 79.25 to 320.36 ± 68.06 cm² (decreased by 20.09%, p = 0.006) at 3 months, to 328.31 ± 52.67 cm² (decreased by 18.11%, p = 0.020) at 6 months, and to 286.40 ± 55.72 cm² (decreased by 28.52%, p = 0.101) at 9 months after LGAE, respectively. But the decrease of abdominal fat loss at 9 months after LGAE was largely due to the reduction in visceral adipose tissue.

CONCLUSIONS

Our study with 9-month data in 5 patients indicates that bariatric embolization of the LGA is a safe and may be a promising strategy to suppress the production of ghrelin and results in weight loss and abdominal fat reduction.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02786108).

Current and cutting-edge interventions for the treatment of obese patients

The number of people classified as obese, defined by the World Health Organization as having a body mass index ≥30, has been rising since the 1980s. Obesity is associated with comorbidities such as hypertension, diabetes mellitus, and nonalcoholic fatty liver disease. The current treatment paradigm emphasizes lifestyle modifications, including diet and exercise; however this approach produces only modest weight loss for many patients. When lifestyle modifications fail, the current "gold standard" therapy for obesity is bariatric surgery, including Roux-en-Y gastric bypass, sleeve gastrectomy, duodenal switch, and placement of an adjustable gastric band. Though effective, bariatric surgery can have severe short- and long-term complications. To fill the major gap in invasiveness between lifestyle modification and surgery, researchers have been developing pharmacotherapies and minimally invasive endoscopic techniques to treat obesity. Recently, interventional radiologists developed a percutaneous transarterial catheter-directed therapy targeting the hormonal function of the stomach. This review describes the current standard obesity treatments (including diet, exercise, and surgery), as well as newer endoscopic bariatric procedures and pharmacotherapies to help patients lose weight. We present data from two ongoing human trials of a new interventional radiology procedure for weight loss, bariatric embolization.

Clinical Safety of Bariatric Arterial Embolization: Preliminary Results of the BEAT Obesity Trial

Purpose To conduct a pilot prospective clinical trial to evaluate the feasibility, safety, and short-term efficacy of bariatric embolization, a recently developed endovascular procedure for the treatment of obesity, in patients with severe obesity. Materials and Methods This is an institutional review board- and U.S. Food and Drug Administration-approved prospective physician-initiated investigational device exemption study. This phase of the study ran from June 2, 2014, to August 4, 2015. Five severely obese patients (four women, one man) who were 31-49 years of age and who had a mean body mass index of 43.8 kg/m2 ± 2.9 with no clinically important comorbidities were enrolled in this study. Transarterial embolization of the gastric fundus with fluoroscopic guidance was performed with 300-500-μm Embosphere microspheres. The primary end point was 30-day adverse events (AEs). The secondary end points included short-term weight loss, serum obesity-related hormone levels, hunger and satiety assessments, and quality of life (QOL) surveys, reported up to 3 months. Simple statistics of central tendencies and variability were calculated. No hypothesis testing was performed. Results The left gastric artery, with or without the gastroepiploic artery, was embolized in five patients, with a technical success rate of 100%. There were no major AEs. There were two minor AEs-subclinical pancreatitis and a mucosal ulcer that had healed by the time of 3-month endoscopy. A hospital stay of less than 48 hours for routine supportive care was provided for three patients. Mean excess weight loss of 5.9% ± 2.4 and 9.0% ± 4.1 was noted at 1 month and at 3 months, respectively. Mean change in serum ghrelin was 8.7% ± 34.7 and -17.5% ± 29 at 1 month and 3 months, respectively. Mean changes in serum glucagon-like peptide 1 and peptide YY were 106.6% ± 208.5 and 17.8% ± 54.8 at 1 month. There was a trend toward improvement in QOL parameters. Hunger/appetite scores decreased in the first 2 weeks after the procedure and then rose without reaching preprocedure levels. Conclusion Bariatric embolization is feasible and appears to be well tolerated in severely obese patients. In this small patient cohort, it appears to induce appetite suppression and may induce weight loss. Further expansion of this study will provide more insight into the long-term safety and efficacy of bariatric embolization. © RSNA, 2017 Online supplemental material is available for this article.

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

Obesity is a public health epidemic in the United States, which results in significant morbidity, mortality, and cost to the healthcare system. Despite advancements in traditional therapeutic options for the obese patients, there is a treatment gap for patients in whom lifestyle modifications alone have not been successful, but for whom bariatric surgery is not a suitable option. Areas covered: This treatment gap needs to be addressed and thus, complimentary or alternative treatments to lifestyle changes and surgery are urgently needed. Recent evidence suggests that embolization of the gastric fundus ('Bariatric Embolization'), which is predominantly supplied by the left gastric artery, may affect energy homeostasis by decreasing ghrelin production. The purpose of this special report is to discuss the background, rationale and latest data on this topic, as well as provide the latest data from the ongoing BEAT Obesity clinical trial. Expert commentary: A multipronged approach is essential in the treatment of obesity. Bariatric embolization looks to treat the hormonal imbalances which contribute to obesity. If proven successful in the long-term, bariatric embolization represents a potential minimally invasive approach to treat obesity offered by interventional radiologists.

Comparison of Weight Loss, Ghrelin, and Leptin Hormones After Ligation of Left Gastric Artery and Sleeve Gastrectomy in a Rat Model

Background

Ligation of the left gastric artery (LLGA), which supplies the fundus of the stomach, may reduce the appetite hormone ghrelin, resulting in weight control. The aim of this study was to compare LLGA and sleeve gastrectomy (SG) in terms of postoperative outcomes in a rat model.

Material/Methods

Fifteen male Wistar albino rats, weighing >350 grams (range 350–525 grams), were enrolled in LLGA (N=5), SG (N=5), and control (N=5) groups. Blood samples were drawn preoperatively and also during the first and fourth week postoperatively to assay ghrelin and leptin hormone levels. Body weight was measured in each group.

Results

The maximum reduction in ghrelin level (41.5%) was found in the LLGA group. Considerable% total weight loss (TWL) (mean 24.1%) was observed in the SG group, and slight%TWL was noted in the control and LLGA groups (means of 0.1% and 2.1%, respectively). There was no significant difference in mean percent weight change between the LLGA and the SG groups (p=0.08). Blood sample analysis revealed no statistically significant changes in ghrelin or leptin levels between the groups (p=0.9 and p=0.3, respectively).

Conclusions

We present evidence that LLGA causes the same reduction in ghrelin hormone levels as SG at 4 weeks after surgery in a rat model. However, LLGA did not cause the same%TWL as SG. The mechanism of weight loss in SG is most likely due to restriction and to the effects of the procedure, rather than due to neurohormonal changes.

Gastric Artery Embolization Trial for the Lessening of Appetite Nonsurgically (GET LEAN): Six-Month Preliminary Data

PURPOSE

To report 6-month safety and efficacy results of a pilot study of left gastric artery (LGA) embolization for the treatment of morbid obesity (ie, body mass index [BMI] > 40 kg/m(2)).

MATERIALS AND METHODS

Four white patients (three women; average age, 41 y [range, 30-54 y]; mean weight, 259.3 lbs [range, 199-296 lbs]; mean BMI, 42.4 kg/m(2) [range, 40.2-44.9 kg/m(2)]) underwent an LGA embolization procedure with 300-500-µm Bead Block particles via right common femoral or left radial artery approach. Follow-up included upper endoscopy at 3 days and 30 days if necessary and a gastric emptying study at 3 months. Tracked parameters included adverse events; weight change; ghrelin, leptin, and cholecystokinin levels; and quality of life (QOL; by Short Form 36 version 2 questionnaire).

RESULTS

Three minor complications (superficial gastric ulcerations healed by 30 d) occurred that did not require hospitalization. There were no serious adverse events. Average body weight change at 6 months was -20.3 lbs (n = 4; range, -6 to -38 lbs), or -8.5% (range, -2.2% to -19.1%). Average excess body weight loss at 6 months was -17.2% (range, -4.2% to -38.5%). Patient 4, who had diabetes, showed an improvement in hemoglobin A1c level (7.4% to 6.3%) at 6 months. QOL measures showed a general trend toward improvement, with the average physical component score improving by 9.5 points (range, 3.2-17.2) and mental component score improving by 9.6 points (range, 0.2-19.3) at 6 months.

CONCLUSIONS

Preliminary data support LGA embolization as a potentially safe procedure that warrants further investigation for weight loss in morbidly obese patients.

Minimally invasive percutaneous endovascular therapies in the management of complications of non-alcoholic fatty liver disease (NAFLD): A case report

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of disorders from simple steatosis to inflammation leading to fibrosis, cirrhosis, and even hepatocellular carcinoma. With the progressive epidemics of obesity and diabetes, major risk factors in the development and pathogenesis of NAFLD, the prevalence of NAFLD and its associated complications including liver failure and hepatocellular carcinoma is expected to increase by 2030 with an enormous health and economic impact. We present a patient who developed Hepatocellular carcinoma (HCC) from nonalcoholic steatohepatitis (NASH) cirrhosis. Due to morbid obesity, she was not an optimal transplant candidate and was not initially listed. After attempts for lifestyle modifications failed to lead to weight reduction, a transarterial embolization of the left gastric artery was performed. This is the sixth such procedure in humans in literature. Subsequently she had a meaningful drop in BMI from 42 to 36 over the following 6 months ultimately leading to her being listed for transplant. During this time, the left hepatic HCC was treated with chemoembolization without evidence of recurrence. In this article, we wish to highlight the use of minimally invasive percutaneous endovascular therapies such as transarterial chemoembolization (TACE) in the comprehensive management of the NAFLD spectrum and percutaneous transarterial embolization of the left gastric artery (LGA), a novel method, for the management of obesity.

The Global Nonalcoholic Fatty Liver Disease Epidemic: What a Radiologist Needs to Know

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of disorders from a benign steatosis to hepatocellular carcinoma (HCC). Metabolic syndrome, mainly obesity, plays an important role, both as an independent risk factor and in the pathogenesis of NAFLD. With the progressive epidemics of obesity and diabetes mellitus, the prevalence of NAFLD and its associated complications is expected to increase dramatically. Therapeutic strategies for treating NAFLD and metabolic syndrome, particularly obesity, are continuously being refined. Their goal is the prevention of NAFLD by the management of risk factors, prevention of progression of the disease, as well as management of complications, ultimately preventing morbidity and mortality. Optimal management of NAFLD and metabolic syndrome requires a multidisciplinary collaboration between the government as well as the health system including the nutritionist, primary care physician, radiologist, hepatologist, oncologist, and transplant surgeon. An awareness of the clinical presentation, risk factors, pathogenesis, diagnosis, and management is of paramount importance to a radiologist, both from the clinical perspective as well as from the imaging standpoint. With expertise in imaging modalities as well as minimally invasive percutaneous endovascular therapies, radiologists play an essential role in the comprehensive management, which is highlighted in this article, with cases from our practice. We also briefly discuss transarterial embolization of the left gastric artery (LGA), a novel method that promises to have an enormous potential in the minimally invasive management of obesity, with details of a case from our practice.

Bariatric embolization of the gastric arteries for the treatment of obesity

Obesity is a public health epidemic in the United States that results in significant morbidity, mortality, and cost to the health care system. Despite advancements in therapeutic options for patients receiving bariatric procedures, the number of overweight and obese individuals continues to increase. Therefore, complementary or alternative treatments to lifestyle changes and surgery are urgently needed. Embolization of the left gastric artery, or bariatric arterial embolization (BAE), has been shown to modulate body weight in animal models and early clinical studies. If successful, BAE represents a potential minimally invasive approach offered by interventional radiologists to treat obesity. The purpose of the present review is to introduce the interventional radiologist to BAE by presenting its physiologic and anatomic bases, reviewing the preclinical and clinical data, and discussing current and future investigations.