Things are starting to heat up in the vascular-medical-device arena. This time, the source of the conflict isn't the device itself, but the doctor-favored mechanism for its delivery.

The delivery of balloon catheters and stents used to clean out and keep open veins and arteries comes in two basic flavors -- over-the-wire and rapid-exchange. The name refers to where the guide wire is during the delivery process. Abbott Labs' (NYSE:ABT) patent on the rapid-exchange technology is set to expire at the end of October, but the company wants a patent term extension for it. And thus, the fight begins.

Privately held AngioScore sent a citizen's petition to the Food and Drug Administration arguing that Abbott didn't deserve an extension under the Hatch-Waxman Act. The act allows drugmakers and medical device companies to recoup some of the time that their patent was in effect, but unusable, because the FDA hadn't yet approved the drug or device.

Essentially, AngioScore argues that Abbott can't ask for a patent extension based on its new Xience V drug-eluting stent, which uses the technology, because the rapid-exchange technology was already used in an approved device back in 2003 and 2004. In other words, Abbott missed its chance.

AngioScore's not the only company that would benefit if the patent extension failed. Medtronic (NYSE:MDT) is also trying to block the patent extension; it expects to have its case heard next month. The company appears to be planning for the worst and hoping for the best, because it hasn't included U.S. sales of the rapid-exchange version of its new drug-eluting stent in any guidance. If Abbott gets turned down, Medtronic will launch its new product version as planned in November.

On the other hand, fellow drug-eluting stent maker Boston Scientific (NYSE:BSX) would probably like to see the patent extended. Under the deal that divided Guidant between Boston Scientific and Abbott, Boston Scientific gets to sell Abbott's Xience V stent under the brand name Promus. Johnson & Johnson (NYSE:JNJ) is probably in the same boat, since it has its own version of the rapid exchange technique.

Sit back and relax, Fools -- we're likely to have a few more rapid exchanges before this fracas is finally settled.

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