SAN DIEGO — A number of experimental treatments for obesity are being developed as alternatives to Roux-en-Y surgery or gastric banding.
Devices that are placed endoscopically or surgically may someday fill a gap between low-risk, low-effectiveness diet/exercise strategies and the higher-risk procedures, Dr. Jeffrey S. Brooks said at a symposium on obesity sponsored by the American Society of Bariatric Physicians.
Only 2% of obese patients undergo Roux-en-Y surgery or gastric banding. Rates of death after open procedures are 2% within a month of surgery and 5% within 1 year (JAMA 2005;294:1903–6). Laparoscopic procedures lower the overall reported mortality rate for Roux-en-Y and gastric banding procedures to 1% or less, he noted.
Alternative devices being investigated include gastric balloons (to fill stomach space and give the sensation of satiety with less food) and gastric stimulation devices (to stimulate quicker gastric emptying).
“At least one of these will hit the streets in 2–3 years,” said Dr. Brooks, a gastroenterologist and chief scientific officer of a company that is developing one of the balloons.
The saline-filled Bioenterics intragastric balloon (BIB) and the air-filled Heliosphere intragastric balloon are in use in some European and South American countries, Mexico, and Canada, he said.
Approximately 2,500 BIBs have been placed in patients in Italy, and studies have ranged from 30 to a few hundred patients.
The BIB contributes to an average weight loss of 15 kg and a five-point decrease in body mass index (BMI) after 6 months, data suggest.
The balloon initially causes severe nausea, but the rate of balloon removal in the first few postoperative days is less than 3%, Dr. Brooks said. Overall rates of removal due to intolerance range from 3% to 9%.
The BIB deflates prematurely in up to 29% of cases, depending on the study. Intestinal obstruction has occurred in 0.3%–5% of patients, and 3% of patients have suffered gastric perforations. The device is contraindicated in patients who have previously had gastric surgery, because they are at highest risk for perforation.
Although supposedly adjustable to fit the patient's size requirements, the BIB is “quite difficult” and not practical to adjust, Dr. Brooks said.
The Heliosphere balloon is relatively easy to put in but very difficult to take out, he said. This double-walled polymer balloon is covered with silicone. Placed endoscopically, it gets inflated with 650–750 mL of air. Like the BIB, it is used for 6 months as an adjunct to diet and exercise.
The removal rate for intolerance is around 6%, and approximately 2% of the devices deflate prematurely, preliminary data suggest.
A third endoscopically placed balloon currently being developed by Dr. Brooks' company, Spatz-FGIA Inc., is expected to be adjustable, he said. Studies in animals so far show no migration or gastric perforations.
Two other companies (Satiety Inc. and Fulfillium Inc.) have filed patents for gastric balloons, but it's unclear if and when they will start clinical studies.
Two kinds of gastric stimulators are in development: one by Transneuronix Inc., which provides continuous stimulation, and one by Metacure, which provides intermittent stimulation when food is ingested.
Impressive European results with gastric stimulation have not been matched by early U.S. data, he noted. A randomized trial of the Transneuronix device in 190 patients in 2004 found that 27% in the stimulator group and 16% in the control group had lost at least 20% of excess weight 1 year later.
“I think it will work for some patients,” Dr. Brooks commented.