In a new weight loss study, Emory doctors demonstrated the safety of freezing a nerve that carries hunger signals to the brain. Researchers found the new treatment may reduce patients’ appetite and help them lose weight. J. David Prologo, MD, FSIR, ABOM-D, interventional radiologist at Emory University School of Medicine and lead author of the clinical trial, presented findings at the Society of Interventional Radiology’s 2018 Annual Scientific Meeting on March 21 in Los Angeles.

"We use image guidance to insert a needle into the patient’s back and with the help of live images from a CT scan, use argon gas to cool the needle and freeze the nerve, known as the posterior vagal trunk," says Prologo, director of Interventional Radiology at Emory Johns Creek Hospital and assistant professor in the Department of Radiology and Imaging Sciences in Emory’s School of Medicine.

The vagus nerve is located at the base of the esophagus and is connected to the brain and branches to many major organs including the digestive system, heart, and lungs, among others.

In the pilot study, 10 people with a BMI between 30 and 37 underwent the procedure and doctors followed them for 90 days. Participants reported decreased appetite and the overall average weight loss was 3.6% of initial body weight and an average decline of nearly 14% of the excess BMI. Investigators say no procedure-related complications or adverse events during follow-up were reported.

The ablated nerve regrows at about one millimeter per day and will fully regrow back after 8 to 12 months. Prologo hopes that the newly regenerated nerve will be less hyperactive, providing a new set point for patients.

"Now that we’ve examined safety and feasibility of using cryoablation on the vagus nerve, we want to conduct a much larger trial to determine the durability of the procedure," says Prologo. The study was funded by HealthTronics/Endocare, a medical technology company that manufactures the ablation probes used for the treatment.