BEATLES: Bariatric embolization using BTG-001933 microspheres is feasible

Bariatric embolization of arteries (BAE) using novel customized tightly calibrated 100-200µm radiopaque embolic microspheres “BTG-001933” (Boston Scientific) is feasible and appears to be well tolerated by patients with severe obesity, according to researchers led by a team from Johns Hopkins University, Baltimore, MD. The researchers noted that weight loss outcomes demonstrated higher efficacy, compared to other embolic agents used in previous studies.

Figure 1: Image from not from this study but from the ‘Bariatric Embolization of Arteries for the Treatment of Obesity (BEAT Obesity) Trial: Results at 1 Year’, published in the journal Radiology. (a) Distribution of various gastric ulcerations observed during endoscopy 1 week after bariatric embolization. Relative sizes and shapes of ulcers are indicated by sizes and shapes of coloured dots on diagram. Each colour represents ulcers found on one participant (eg, the three black dots represent ulcers on one participant).The curved purple line represents a linear ulcer. The ulcer represented as a yellow oval and enclosed by a blue square corresponds to that shown in (b)-(d). (b)-(d) Endoscopic images of the same location in one participant (48-year-old African American woman with a baseline weight of 127 kg): (b) at baseline, (c) at 2 weeks after embolization (arrow indicates a small, superficial gastric ulcer, measuring 1 cm on the longest axis), and (d) at 3 months after embolization (arrow indicates prior location of the ulcer). Credit: Radiological Society of North America

Left gastric artery embolization is a minimally invasive medical procedure used to treat obesity by reducing blood flow to the fundus, decreasing appetite and food intake, leading to weight loss. To examine the efficacy of the procedure on weight loss, US researchers established the ‘Bariatric Embolization of ArTeries with imaging visibLe EmbolicS (BEATLES)’ pilot study, utilising the BTG-001933 microspheres. The pilot phase started in Oct 2020 with one-year follow up due in Dec 2023. These initial outcomes were presented by Dr Adham Khalil from Johns Hopkins, at the annual meeting of the Society of Interventional Radiology (March 23 to 28) in Salt Lake City, UT.

The procedure was performed under moderate sedation with radial or femoral vascular access achieved using a small gauge needle, dilated over a guidewire to accommodate a 5 French vascular sheath. The microcatheter is guided into the left gastric and/or gastroepiploic arteries supplying the fundus and small calibrated spheres were infused until stasis of anterograde arterial flow was achieved, with particular care to avoid infusion of non-target arteries. The left gastric and/or gastroepiploic arteries were embolized.

Ten participants (mean age 38.3±9.4 years, 9 females) with class II-III obesity were included in this presentation. The left gastric artery (10) was embolised with or without the gastroepiploic artery (6) with a 100% technical success rate. No major adverse events (AEs) were reported with minor AEs including a healing mucosal ulcer at three-month endoscopy and a vascular access site pseudoaneurysm (unrelated). Post-procedure MRI showed weight-to-muscle volume ratios were 10.3±1.9, 10.0±0.5 and 9.2±1.3 kg/L (Rrm=0.89, p=0.001, 95%CI 0.64-0.97) at baseline, three and six months, respectively.

The authors concluded that BAE using 100-200µm radiopaque embolic microspheres  is feasible and associated with significant muscle-sparing weight loss via subcutaneous and intra-muscular fat reduction.