Willis Parsons, MD, director of the gastroenterology center at Northwest Community Hospital (Arlington Heights, Illinois), remembers what it was like to treat esophageal cancer patients with plastic stents before self-expanding metal stents were introduced.

"The market was changed dramatically probably a little over 15 years ago with the advent of the self-expanding metal stents," Parsons told Medical Device Daily. "Prior to that the technology was just terrible, almost barbaric."

As if this group of patients had not already suffered enough, trying to squeeze one of these plastic stents in was quite difficult and resulted in a high perforation rate, Parsons said.

Now, Cook Medical (Bloomington, Indiana) has received FDA 510(k) clearance for its Evolution controlled-release esophageal stent system, a device Cook hopes will bring some long-overdue innovation to the market.

"This product is going to make a real difference; we think it's going to shake up the market, we think as a disruptive technology," Barry Slowey, VP of global sales and marketing for Cook's Endoscopy division, told MDD.

The Evolution stent system, cleared for use in patients with esophageal cancer, is designed to reduce the risk of migration and give physicians more control over the placement of the stent.

Slowey said Boston Scientific (Natick, Massachusetts) has dominated the esophageal stent market.

"10 years ago [Boston Sci's stent] was a pretty good, novel introduction system, better than what was out at the time," Slowey said. "Now doctors are saying that the stent doesn't give them much control," he said.

When treating patients with esophageal cancer, Slowey said, doctors are trying to get the stents aligned within the tumor so they are trying to get part of the stent above and part of it below the tumor.

Cook has been working on the Evolution stent for about three years, Slowey said, and designed the device using input from gastroenterologists who said they wanted a more controlled delivery system for precise placement and a stent with a low risk of migration.

The company came up with a device that has a pistol-grip deployment system so that the doctor can squeeze a trigger and only 8 mm of stent deploys at a time. The stent itself is about 8 cm to 15 cm long.

"We've given them a very controlled-release stent," Slowey said.

Another complaint Cook heard from doctors about other esophageal stents is that sometimes they will get up to 50% into the deployment and find that the stent is not exactly where it needs to be. So the Evolution stent system features a button that allows doctors to retract the stent, 8 mm at a time, if they are unhappy with the placement.

"The problem we've best addressed is the issue of placement, which was our biggest concern when we heard back from gastroenterologists," Slowey said.

The ability to place the stent precisely the first time may reduce the need for repeat procedures, the company noted.

"It gives them peace of mind ... they want sort of a Get-out-of-jail card," Slowey said.

Cook also noted a directional button on the device that enables switching from deployment to recapture mode and a "point-of-no-return" mark designed to alert the physician when recapture is no longer available. However, even after this point repositioning is still an option, the company said.

Parsons said he has put in "just about every one" of the self-expandable metal stents which are available in all different shapes and sizes "and there is not one that's perfect. There is definitely room for improvement and it's a very complex group of patients."

But if there is one thing that will make the Evolution stent system take off it will be its slow, controlled deployment mechanism and the ability to recapture the stent, Parsons said.

"It's easy to deploy, which is a key issue because not everyone who puts in metal stents are experts," Parsons said. "The reality is these patients are all over the planet in small hospitals and big hospitals."

Slowey said Cook also addressed the issue of migration because about 10% to 15% of stents slip into the stomach after they are deployed. The "dog bone" or "dumbbell" shape of the stent helps anchor it in place because the top and bottom parts are larger than the part of the stent within the structure.

Also, Slowey said the company left the top 2 cm and bottom 2 cm of the stent uncoated to help reduce the risk of migration.

According to Cook, the Evolution also is the only esophageal stent with an internal and external silicone coating, designed to resist tumor ingrowth into the stent and enhances the patients' ability to swallow food normally instead of eating through a tube.

Cook has a CE-mark for the Evolution stent system and already has released the device in Europe, and just recently launched it in the U.S. and Canada.

Although the stent system is only cleared for malignancies, Parsons said that about 90% of patients who need an esophageal stent have cancer.

The device "holds great promise," Parsons said. "I think it's going to make the physician's job easier and less stressful, this tends to be a higher-stress type of procedure so if the early data holds true, it should have a significant impact in my practices."