Sealing off an artery that supplies blood to the portion of the stomach that produces the hunger- promoting hormone ghrelin reduced appetite and triggered weight loss in the first study of the approach in human volunteers. The experiment involving five obese patients in Tbilisi, Georgia, found the procedure led to an average weight loss of 30 pounds within the first month and 45 pounds after six months, said lead researcher Nicholas Kipshidze. The results will be presented this weekend at the American College of Cardiology meeting in San Francisco.
The researchers threaded a catheter from an artery in the groin to the gastric artery, where they released tiny beads that blocked off blood flow to the stomach, Kipshidze said in a telephone interview. While the 30-minute procedure led to less weight loss than standard bariatric surgery, it wasn't as invasive and it is faster, he said. Three patients had stomach discomfort, though there were no other complications, he said.
"We are cutting off blood flow to the fundus of the stomach, which is known as the area where a lot of hormones are initiated," said Kipshidze, who led the study when he was the physician-in-chief at Republican Hospital in Tbilisi.
"The theory is that we are decreasing secretion of the hormones, including the appetite hormone ghrelin."
The patients reported decreased appetite the day after the procedure, he said. They didn't change their diets or begin any exercise programs. The researchers were worried that sealing off blood flow may increase the risk of tissue damage, though follow up exams including imaging of the stomach wall showed no problems, he said.
Animal studies have shown blocking off the gastric artery can lead to a systemic suppression of ghrelin, said John Harold, professor of medicine at Cedars-Sinai Heart Institute in Los Angeles and president-elect of the American College of Cardiology. Existing technology that includes gastric bypass and stomach banding has been used for the past two decades to perform weight loss surgery on humans, and has been approved by the U.S. Food and Drug Administration since 2001.
"I would assume the risk of embolization is not insignificant and would have to be weighed against existing techniques that have a proven track record," he said.
Kipshidze is planning another study that will follow more patients for a longer period, and include a comparison group for control. The researchers are also designing surgical tools and implements that may be used during the procedure, he said. They are also considering an approach that would allow them to begin in the radial artery in wrist, rather than the femoral artery in the groin, which could speed the healing time even more.
"I believe it may become a good alternative to bariatric surgery," Kipshidze said. "Still, five patients is only five patients. I am cautiously optimistic."