The results of a study presented at SIR 2018 suggest that cryoablation of the posterior vagal trunk in patients with mild-to-moderate obesity is a safe and effective procedure for suppressing appetite and encouraging weight loss. J. David Prologo, MD, FSIR, presented the results of the study, “Percutaneous CT-guided cryovagotomy for the management of mild–moderate obesity: A pilot trial,” in an abstract presentation Sunday.
“The epidemic of obesity is the greatest public health challenge we face in this country,” said Dr. Prologo, who is assistant professor in the Division of Interventional Radiology and Image Guided Medicine at Emory University School of Medicine and director of Interventional Radiology Services at Emory Johns Creek Hospital in Atlanta.
“For people who are severely obese, bariatric surgery is an option, but that leaves us with millions of people in the 30–37 BMI range who don’t qualify for surgery but who are at increased risk for an incredible number of downstream diseases, including heart disease, diabetes and osteoarthritis, among others,” he said.
Lifestyle changes such as diet and exercise are the most commonly recommended approach for weight loss in this population and, while it can be an effective approach and should be part of any long-term weight management strategy, the failure rate is high. What’s lacking, Dr. Prologo said, is an understanding of why people fail.
“We provide people with an infinite number of combinations on how to restrict their calories and how to exercise, but we don’t address the fact that most people just can’t do it,” he said. “Making matters worse, when lifestyle interventions fail, there is a tendency in our society to simply ascribe it to weakness or a lack of willpower.”
Dr. Prologo believes, however, that the biggest reason so many people find themselves unable to stick to a diet, for example, is because their body won’t let them.
“It’s the backlash from an empty stomach. A signal from the vagus nerve is carried to the brain that you better eat or you’re going to die, and that causes you to forget about everything else, including why you started to diet,” Dr. Prologo said. “In this study, we set out to see if we could use an interventional radiology skill set to reach that nerve, apply ablative technology to attenuate the hunger signal and, hopefully, help people control their appetite when they restrict their calories.”
In this study, Dr. Prologo and his colleagues looked at 10 patients (eight female, two male, mean age 44 ± 12 years [range 27-66]) with 30 > BMI > 37 who underwent percutaneous CT-guided cryoablation of the posterior vagal trunk along the distal esophagus. Anthropometric measurements were obtained at baseline and at each follow-up visit (7, 45 and 90 days, post procedure). In addition, each subject was administered a Patient Global Impression of Change Tool for evaluation of appetite.
Dr. Prologo reported that the technical success rate for the procedure was 100 percent with no procedure-related complications or adverse events observed during follow-up.
The average total weight loss and excess BMI lost were 3.6 percent and 13.9 percent, respectively, at 90 days. Further, all patients reported decreased appetite at all follow-up points after the procedure — 17 percent reported “somewhat less appetite,” 30 percent reported “much less appetite,” and 53 percent reported “very much less appetite.”
“In addition to not feeling hungry, patients reported that they were getting fuller faster,” he said. “Not only does that nerve carry the hunger signal to the brain, but it also moves foods through the stomach, so we’ve also slowed the transit of food through the stomach by ablating the nerve.”
While these findings are encouraging, Dr. Prologo said the next step is to validate the findings in a randomized controlled study.
“First and foremost, this was a safety and feasibility study,” he said. “We wanted to make sure that we could do it and people were safe, and we did. If we can validate our results in a larger study with a control arm, the downstream implications of stopping the progression of obesity in this population are tremendous.”