The U.S. Food and Drug Administration today allowed marketing of the AXIOS Stent and Delivery System for treating pseudocysts (fluid and tissue filled cavities) that form in the pancreas and are next to the stomach or small intestine. This is the first stent that is specifically designed for drainage of a pancreatic pseudocyst by creating a new, temporary opening between the pancreas and the gastrointestinal tract.
The pancreas is an organ located in the upper abdominal area behind the stomach that produces insulin for the regulation of blood sugar and many enzymes that are important for the digestion of carbohydrates, fats, and proteins. The organ contains a system of ducts feeding into one larger duct that drains enzymes into a segment of the small intestine, known as the duodenum, where the enzymes are mixed with food to provide for normal digestion.
The pancreatic ducts sometimes become blocked from gallstones or after an injury to the pancreas, causing the enzymes that normally drain into the small intestine to be released directly into the pancreas, which can causes a pseudocyst to form. Most pseudocysts are small and resolve on their own, but some pseudocysts can become very large (from 7 to more than 50 centimeters wide) and can become infected with bacteria. Infected pseudocysts are almost always painful and may lead to serious blood infections that can be life-threatening.
"Pancreatic stents currently on the market are indicated for pancreatic drainage and are to be placed through the pancreas' existing ducts, but this frequently does not provide adequate drainage of a pseudocyst," said Christy Foreman, director of the Office of Device Evaluation in the FDA's Center for Devices and Radiological Health. "The AXIOS Stent provides a new option for physicians to effectively treat pseudocysts with a less invasive intervention than surgical removal of the pseudocyst."
The AXIOS Stent is a wire mesh tube with a silicone covering. The stent is tightly compressed and is enclosed within a catheter (a long, hollow, flexible tube), the AXIOS Delivery System. The catheter, with the AXIOS stent, is placed into the stomach through an endoscope that is passed through the patient's mouth and down into an area of the stomach adjacent to the pseudocyst. After creating a small opening in the wall of the stomach and a small opening in the pseudocyst, the surgeon positions the still-compressed stent across both openings, releases the stent and removes the delivery system. Once expanded, the stent allows the contents of the pseudocyst to drain into the stomach. Once the pseudocyst has drained and decreased in size, the physician can use standard endoscopic tools to remove the AXIOS Stent.
The AXIOS Stent can expand to a diameter of over one half of an inch. Compared to the narrower, plastic stents that are currently on the market, the AXIOS Stent may be less prone to becoming blocked by solid material inside of the pseudocyst because of its wider diameter. The wider diameter of the AXIOS Stent also allows physicians to pass endoscopic tools into the pseudocyst to clean or remove the contents of both the stent and the pseudocyst.
The FDA's review of the AXIOS Stent and Delivery System included review of a clinical study of 33 study participants meeting study eligibility requirements including having a pancreatic pseudocyst at least six centimeters in diameter. The study looked at the following safety and effectiveness factors: the ability of physicians to successfully place the stents, whether the stents stayed in place during treatment, whether the stents remained open during treatment, tissue reactions after the stent was removed, and whether the stent reduced the size of the pseudocyst. Investigators followed up with study participants three and six months after their stent or stents were removed.
The study data showed that physicians were able to successfully place the stents 90.9 percent of the time and that 97 percent of stents successfully implanted stayed in place for the duration of pseudocyst treatment (up to 60 days). Ninety-three percent of the stents remained open to allow for drainage of the pseudocyst for the duration of treatment, and 86 percent of the treated pseudocysts decreased in size by at least 50 percent. All stents were removed without injury to the surrounding tissue. Adverse events observed included abdominal pain, nausea and vomiting.
The FDA reviewed the AXIOS Stent and Delivery System through the de novo premarket review pathway, a regulatory pathway for some low- to moderate-risk medical devices that are not substantially equivalent to an already legally marketed device.
The AXIOS Stent and Delivery System is manufactured by Xlumena, Inc. of Mountain View, Calif.
December 18, 2013