Patients receiving a new, minimally invasive procedure for obesity experienced measurable weight loss and appetite suppression for up to one year according to a new clinical trial led by Johns Hopkins Medicine researchers. The findings add to evidence of the safety and effectiveness of an experimental procedure, bariatric embolization, which can be a potential tool to combat obesity.

Bariatric embolization is an image-guided procedure in which microscopic beads are delivered into the stomach’s arteries to block blood flow in the upper part of the stomach to suppress levels of the hunger-stimulating hormone ghrelin. 

Patients receiving a new, minimally invasive procedure for obesity experienced measurable weight loss and appetite suppression for up to one year according to a new clinical trial led by Johns Hopkins Medicine researchers. The findings add to evidence of the safety and effectiveness of an experimental procedure, bariatric embolization, which can be a potential tool to combat obesity.

Bariatric embolization is an image-guided procedure in which microscopic beads are delivered into the stomach’s arteries to block blood flow in the upper part of the stomach to suppress levels of the hunger-stimulating hormone ghrelin.

According to the researchers, these findings, which are published in the April issue of the journal Radiology, may open the door for a safe and less invasive way to lose weight, especially for those who are morbidly obese with a body mass index (BMI) of 40 or more.

“This is a great step forward for this procedure in establishing early feasibility, safety and efficacy,” says Clifford Weiss, M.D., lead author on the study, associate professor of radiology and radiological science at the Johns Hopkins University School of Medicine, and medical director of the Johns Hopkins Center for Bioengineering, Innovation and Design. “It is extraordinarily fulfilling to all of us to see something that started as an idea develop through more than 12 years of collaborative research and then go all the way to an initial clinical trial.”

In recent years, bariatric embolization has evolved into a revolutionary treatment for obesity, with Weiss leading one of the past studies. First, in 2008, a Johns Hopkins-led research team showed suppressed levels of ghrelin in pigs. Then, in 2016, Weiss and his research team reported the protocol for the current clinical trial and the initial safety data on how the procedure seemed to initiate weight loss, dramatic hunger reduction and lower levels of ghrelin in humans.

According to the Centers for Disease Control and Prevention, obesity is a public health crisis in which over 93 million Americans and hundreds of millions of people globally are affected. It has been proved that traditional treatments such as behavior therapy, diet and exercise do not sustain weight loss in many patients. This lack of efficiency has driven the need for surgical l interventions including sleeve gastrectomy, gastric bypass and gastric banding. Although effective, these surgeries may pose risks, which further drives the need for minimally invasive, cost-effective options such as bariatric embolization.

During a 12 month period, the researchers assessed the procedure’s effects on 20 severely obese participants — 16 women and four men, ages 27–68, with a BMI between 40 and 56 and an average weight over 300 pounds. Of the women, 5 were Caucasian and 11 were African American. Of the men, three were Caucasian and one was African American.

All patients received comprehensive weight management services, either through the Johns Hopkins Weight Management Center (15 patients) or a weight management group at Mount Sinai Hospital in New York (5 patients).

To perform the embolization, the researchers delivered the microscopic beads into the arteries through a small catheter inserted in a tiny nick in the skin of the groin or wrist. Thus, the procedure is thought to be less invasive. The beads are then directed into the stomach’s arteries to block blood flow in the upper part of the stomach, the fundus.

It is hypothesized that this reaction suppresses production of the “hunger hormone” ghrelin. The cells in the fundus are  more active at pumping out the hunger hormone than neighboring cells and are also more sensitive to having blood flow cutoff.

All participants were encouraged to visit their weight management team to help assess their diet, weight loss, physical activity, hunger, and lifestyle improvements.The researchers report the procedure was performed successfully for all 20 study participants with no major side effects.

The participants were shown to experience weight loss at 8.2 percent during the first month, 11.5 percent during the third month, 12.8 percent during the sixth month and 11.5 percent during the 12th month. Overall, the embolization resulted in a mean excess-weight loss of 11 percent and a mean total weight loss of 7.6 kilograms — or a little less than 17 pound.

According to the researchers, 5 percent total weight loss is clinically significant with proven health benefits.

“Most of these patients either had failed multiple times when using traditional diet and exercise programs or had never been able to ever lose or sustain weight loss in the past until our clinical trial,” Weiss adds.

Peak weight loss was recorded during the sixth month. Only three participants had returned to their baseline weight during the 12th  month. No participants were heavier than their baseline weight.

Participants experienced a decrease in hunger and an increase in of satiety when eating. Maximum appetite suppression occurred in the first month. Hunger decreased for four weeks after embolization and increased thereafter, without reaching pre-embolization levels. Although appetite increased steadily, it remained 26 percent lower in the 12th month than the first month.

Metabolic changes in the patients were observed, with decreases in total cholesterol and increases in high-density lipoprotein (HDL), the so-called “good cholesterol.” From the first to the third month, total cholesterol levels decreased. By the 12th month, total cholesterol levels were lower than in the first month. Lipoprotein decreased during the first month after embolization but increased at all subsequent time points.

Quality of life surveys that tested for physical function, self-esteem, sexual life, work life and public distress were given to the participants and began to show improvement in the third month. During the 12th month, physical function scores increased from 55 to 70, self-esteem scores improved from 50 to 72, sexual life scores increased from 61 to 88, public distress scores increased from 68 to 79 and work scores increased from 73 to 88.

The participants also reflected clinical changes after bariatric embolization, such as improved cardiovascular health and prevention of diabetes.

“This is the result of collaborative research, of step-by-step basic and translational science, to get to the point where we could do a clinical trial safely,” says Weiss. “We had a multidisciplinary team, including interventional radiologists, gastroenterologists, registered dietitians, psychologists, hormone experts, bariatric surgeons and statisticians, examining from all different angles to ensure we were investigating it in a rigorous and scientific manner.”

While the findings show promise for a less invasive weight loss option, the researchers caution that the study had several limitations. The small sample size, with an unequal distribution of participants between centers and the lack of a control group, limited the data.

Some participants did not have continuous follow-up throughout the study or did not return some questionnaires, resulting in inadequate data for some endpoints. Between study sites, lifestyle and weight management counseling varied. This presents a challenge for establishing the efficacy of bariatric embolization for weight management. Lastly, African American women were overrepresented in this study, making the results less generalizable to all populations because of genetic differences in weight gain and loss among people of different ethnicities.

Weiss says future studies are needed to establish long-term safety, mechanism of action and procedural efficacy in comparison to a mock treatment. The researchers have been tracking hormonal changes in the patients and are preparing to release results soon, which show longer-term outcomes and the possible impact of the placebo effect.

The researchers hope bariatric embolization will one day become a standard of care in a more personalized approach to treating obesity, a disease increasingly understood to affect each patient differently.

On the Web:

• Johns Hopkins Researchers Suppress ‘Hunger Hormone’

• Early Data from Clinical Trial Indicates Safety and Efficacy of New Weight Loss Procedure

• Johns Hopkins Interventional Radiology Annual Report