Stopping Hunger at the Cerebral Source
The answer to the rising obesity epidemic has typically been increased emphasis on better diet, exercise and, in extreme cases, surgery. A Minnesota company has pioneered new technology to help control obesity with less mess than its surgical predecessors. Since 1991, a new measurement has been used as the standard for consideration for most surgeries: the body-mass index (BMI). BMI is measured in weight (in kilograms) divided by height (meters squared). A BMI of over 30 is considered obese, whereas a BMI of over 40 indicates morbid obesity. Past this threshold, serious health conditions, including atherosclerotic cardiovascular disease and liver disease, shorten life expectancy and reduce quality of life.
In order to manage weight, some patients undergo bariatric surgery to assist in returning to a normal lifestyle. A popular surgical choice to combat obesity has been gastric bypass surgery, an open surgery that divides the stomach into two sections, with the smaller section filling up with food first. This section sends the “full” signal to the brain. Recent surgical developments in camera technology have lead to a type of surgery called laparoscopic surgery, where incisions are cut small enough for the operating tools and cameras to be inserted and operated remotely. Though more difficult, laparoscopic surgery leaves smaller scars and reduced blood loss. However, gastric bypass surgery is an expensive and time-consuming endeavor for the surgeon and the recovering patient.
EnteroMedics, however, thinks it doesn’t have to be. The St. Paul, Minnesota-based company was established in 2002 to develop and commercialize a platform to treat vagal nerve-related diseases. Because the vagus nerve is the primary nerve controlling signals to the brain for hunger and satisfaction, EnteroMedics has opted to focus on obesity management. The EMPOWER! study is a five-year controlled study to determine the effectiveness of a new treatment for obesity, tentatively titled VBLOC therapy. The UC Irvine Medical Center in the city of Orange is hosting the EMPOWER! study for the Southern California area.
Instead of surgically altering the stomach and small intestine to reduce the size of the stomach, VBLOC therapy involves laparoscopically inserting leads to block vagal nerves between the stomach and brain. High-frequency, low-energy electrical impulses are delivered by the leads to block messages of hunger to the brain. A belt control system regulates the pulses, allowing the system to be turned off during mealtime. “There’s no real altering of the anatomy like in other gastric surgeries,” an EnteroMedics nurse commented, “it’s not as invasive and able to be reversed.”
The EMPOWER! Study is recruiting patients who exhibit specific health criteria to participate in a five-year study to test the new technology. Over 220 patients will be treated at up to 15 sites in the United States and Australia. The study is placebo-controlled, meaning one-third of the participants will unknowingly receive a belt system that is turned off in order to test the effects of the diet and exercise regimen with and without the assistance of the belt.
“It’s kinda cool, as far as a new procedure is concerned,” said second-year biological sciences major Steven Blue. “I’m all for the advancement of new technology, especially in complicated fields like gastric science. So if it’s safer, that’s cool.”
Dr. Ninh Nguyen, a specialist in laparoscopic gastric bypass surgery at the UCI Medical Center, is also head of the local chapter of the program. Nguyen is the chief of the division of Gastrointestinal surgery at the UCI Medical Center and received the Golden Scope Award from the Society of American Gastrointestinal & Endoscopic Surgeons in 2002.
An early VBLOC study of 33 obese patients outside the United States prior to the EMPOWER! study has produced promising results in nine of the earliest patients admitted, with an excess weight loss (EWL) of 22.1 percent after nine months of treatment. Although the results are almost certainly not typical, these early indicators are promising for the future of obesity treatments.