A Medical Device Daily

In-stent restenosis is a major issue when it comes to percutaneous coronary intervention of coronary vessels, often requiring patients to undergo repeat procedures, or more invasive surgery. And this is an even more vexing problem when it comes to occluded vessels of the lower leg.

Med-tech companies have been struggling to find a solution for this area of the vasculature.

“You can try balloon angioplasty,” Will McGuire, COO of Spectranetics (Colorado Springs, Colorado), told Medical Device Daily. “But data will tell you the success rate of this is fairly low.”

Spectranetics is banking on a technique combining its Turbo elite laser catheters in combination with its recently FDA-cleared Turbo-Booster. The Turbo-Booster functions as a guiding catheter facilitating directed ablation of blockages in the main arteries at or above the knee.

The Turbo-Booster, combined with Turbo elite laser catheters, enables removal of large amounts of plaque material within the superficial femoral artery and popliteal arteries, Spectranetics says, and the company has just started a prospective registry of 100 patients, the PATENT trial, at up to 10 sites in Germany, with enrollment of the first patient.

The company submitted its 510(k) application to the FDA for its Turbo-Booster in May (Medical Device Daily, May 11, 2007). That came just two months after the company said it stopped its CELLO trial, with the FDA’s approval, after completing about three quarters of enrollment. The trial was stopped, the company told MDD at the time, because its preliminary data was strong enough to meet the endpoints (MDD, March 16, 2007). It then received FDA clearance of the Turbo-Booster in July.

So why the additional trial?

The details are devilish, the company says.

“We don’t have [FDA] clearance to treat in-stent restenosis using both of the technologies,” McGuire said – meaning both the Turbo elite laser and the Turbo-Booster. “In Europe we have a pretty broad clearance. But the PATENT trial will allow us to collect clinical data in a controlled manner. We would like to get a similar indication in the states.”

Data derived from the trial will be able to give the company more ammunition to win FDA approval.

The trial will assess patency with the use of duplex ultrasound at various intervals up to 12 months following the procedure. It will also follow patients for up to one year as a measure to see if there are any adverse affects.

PATENT is expected to be completed within 30 months, according to the company.

Spectranetics said that in the first procedure a patient with four local lesions was treated with the Turbo-Booster and Turbo elite 2.0 mm catheters in a 20 cm long SFA.

“The initial result from this Spectranetics device looks very promising, as the new features allow for ablation of more tissue in larger vessels,” said Andrej Schmidt, MD, of the University of Leipzig-Heart Center.

“In-stent restenosis in a superficial femoral artery represents one of the most challenging procedures in our practice, he said. “The current standard of care, such as repeat balloon angioplasty, does not have good results as these lesions tend to reoccur. We are very excited with the start of this study in Germany, and we look forward to examining the mid- and long-term results of this new therapy.”

If successful, the company could have the first procedure to deal with in-stent restenosis in this sector.

John Schulte, president/CEO of Spectranetics, in a company statement, said, “We believe that instent restenosis in the superficial femoral artery may represent 25% to 35% of all above-the-knee procedures.” And he expressed hope that the trial will help offer help where “there is currently not a good solution for this challenging lesion subset.”

Spectranetics laser systems are used to ablate lesions into tiny particles that are absorbed into the bloodstream. The company’s disposable catheters use high-energy “cool” ultraviolet light to vaporize arterial blockages in the legs and heart, as well as scar tissue encapsulating pacing and defibrillation leads.

The company reports that its CVX-300 excimer laser is the only system approved in the U.S., Europe, Japan and Canada, for use in multiple, minimally invasive cardiovascular procedures.