This procedure really hit a nerve. The vagus nerve, to be specific. According to a presentation at the Annual Scientific Meeting of the Society of Interventional Radiology in Los Angeles, freezing part of the vagus nerve seemed to result in decreased appetite and weight loss in 10 patients. But if you think a study with just 10 patients proves that a procedure is an effective and safe weight loss measure, you really have some nerve.
What is your vagus nerve? Well, it is pronounced like the second half of Las Vegas and coincidentally regulates a number of unconscious processes such as your heart rate, hunger, and digestion. What happens in your vagus nerve doesn’t stay in your vagus nerve. This nerve transmits signals between your brain and your heart, lungs, esophagus, stomach, and other parts of your abdomen.
Therefore, a team led by Dr. David Prologo, an interventional radiologist at the Emory University School of Medicine, thought that freezing the posterior trunk portion of this vagus nerve may be able to reduce hunger. To do this, they used a CT machine to guide through each patient’s back the insertion of a tube that could then deliver the freezing material.
For the study that Prolongo presented in Los Angeles, the team conducted this procedure on only 10 people, who had body mass indices (BMIs) ranging from 30 and 37 and ages ranging from 27 to 66 years of age. When the researchers checked with the patients 7, 45, and 90 days after the procedure, all 10 patients reported having less appetite. Ninety days after the procedure, the average weight loss was 3.6%, and the average decrease in BMI was 13.9%. Here are the results:
Does this mean that the interventional radiologists have found a new weight loss procedure?
Before you jump to conclusions, freeze. Keep in mind the numerous limitations of this study. First of all, there’s a big difference between presenting study results at a meeting and publishing it in a respected scientific journal after it has undergone peer-review. Secondly, this study had fewer subjects than a soccer team and no controls. Could this just be a placebo effect? In other words, maybe the patients had less appetite because they thought the procedure would decrease their appetite? Finally, weight loss over 90 days is only weight loss over 90 days. Who knows how long any of these effects may last and what negative consequences may emerge if the procedure needs to be repeated?
The other issue is that the vagus nerve handles a variety of functions beyond regulating hunger. It’s not clear yet what other functions may be disrupted by freezing even just a portion of the nerve. Did the research team do enough to monitor these other functions of the vagus nerve? What side effects may the procedure have immediately and eventually? It may take longer than 90 days for potential side effects to manifest. Like Las Vegas, the vagus nerve still has many mysteries.
Nevertheless, this procedure may have some promise for patients who can’t seem to lose weight by lifestyle changes. But more testing and studies are needed before you can say viva las vagus nerve freezing.
