Transcatheter bariatric embolotherapy (TBE) for obesity is safe and leads to clinically significant weight loss in comparison to a sham procedure, a hotline and innovation session at PCR e-Course 2020 (25–27 June) has been told. TBE also demonstrated a greater improvement in quality of life and hunger scores. Vivek Y Reddy (Homolka Hospital, Prague, Czech Republic, and Icahn School of Medicine at Mount Sinai, New York, USA) presented the findings from a pilot, single-blind, sham procedure randomised controlled trial.
Reddy told the online audience: “Bariatric surgery is a highly effective procedure, and improves cardiovascular outcomes as well as mortality, but this invasive surgical procedure has significant morbidity and mortality associated with it, and that limits its utility to those patients who are severely obese, with BMIs [body mass index] almost always over 40. TBE is a novel catheter-based approach. It involves embolisation of microspheres to the left gastric artery [LGA] to cause ischaemia to the gastric submucosa. A number of preclinical studies, as well as clinical case series, have indicated that bariatric embolotherapy promotes weight loss—thought to be due to a mechanism of reducing ghrelin, which is the only known appetite-stimulating hormone in the body, and is secreted largely from the gastric fundus.”
The current study compared TBE to a sham procedure in a first-in-human trial conducted at two centres in Prague, The Czech Republic (PIs: Petr Neuzil MD PhD & Martin Fried MD). The first was a bariatric surgery centre that conducted most aspects of the trial, including patient enrolment, consent, weight counselling, and all of the follow-up. The second centre performed the randomisation and treated patients, either with embolotherapy or the sham procedure.
Key inclusion criteria were a BMI of between 35 and 50, and age 21–60 years. Patients were excluded if they had had prior bariatric surgery, had a history of ulcers, had type 2 diabetes, an active H. Pylori infection, or if they were chronic users of aspirin or non-steroidal anti-inflammatory drugs (NSAIDs).
Randomisation of consenting patients was 1:1 to TBE or a sham procedure. In TBE, femoral arterial access was obtained and a coeliac angiogram using a 6Fr guide was performed. Using an occlusion balloon microcatheter, beads which ranged between 300 µm and 500µm were injected into the LGA to achieve stasis. Injection was performed using a custom robotic manifold designed to inject the beads at the correct pressure. The Sham procedure involved the infiltration of lidocaine into the skin in the femoral area, and propofol was infused for one hour.
The primary efficacy endpoint was total body weight loss compared between TBE and sham therapy. Age, weight, and BMI were similar across the two groups. Patients were analysed in both intention-to-treat (ITT) and per protocol (PP) populations. After six months’ follow-up, crossover was permitted. TBE patients were followed for one year and sham patients for six months. After exclusions and withdrawals, 40 patients were randomised, 20 to each group. Following treatment, analysis of efficacy and safety was performed on 19 patients in the ITT population in the TBE group and on 18 patients in the sham group. The PP analysis of efficacy was performed in 15 patients treated with TBE and 16 with sham procedure.
Mean procedure time for TBE was 82.3 minutes. In 16 patients one vessel was injected, two were injected in two patients, and three in the remaining patient of the original 20 randomised to the procedure (19 treated with TBE).
Reddy announced the outcomes: “On the safety side, there was only mild nausea or vomiting that was self-limited, and minor ulcerations in five patients. All of these ulcers were asymptomatic and were self-limiting, requiring no additional treatment.”
At six months, the primary endpoint of weight loss for the ITT population was 7.4kg in the embolotherapy group versus 3kg in the control group (p=0.034). In the PP population, it was 9.4kg in the TBE cohort compared with 1.9kg for the sham therapy (p=0.0002). A comparison of TBE from baseline to 12 months found a 7.8kg loss in the ITT population (p=0.0011), and a 9.3kg loss in the PP population (p=0.0005). In addition, at both six and 12 months from baseline, TBE treatment led to a greater improvement in quality of life measures than sham treatment for physical function, self-esteem, sexual life, public distress, and work, as well as overall quality of life. Hunger scores also decreased to a greater extent for TBE than sham treatment at both six and 12 months from baseline.
Reddy concluded: “In this randomised pilot trial we established the proof of principle that transcatheter bariatric embolotherapy of the left gastric artery is safe, and it promotes clinically significant weight loss. There was an improvement in the hunger scores, significant weight loss that was maintained out to one year, and this also translated to improvements in quality of life.”
Reddy told Interventional News: “We believe this is an important trial that convincingly demonstrates for the first time that TBE helps promote weight loss. However, there is much additional work that remains to be done—most importantly a large multicentre trial to assess efficacy in the hands of a large number of operators, rare safety events that can only be identified after treating a large number of patients, and corroborating data on hormones (for example, ghrelin). My understanding is that the company that sponsored this pilot study is planning to conduct a large US pivotal FDA trial using a second generation TBE system (micro-infusion catheter and robotic manifold).
