If you're an investor in a public medical device company with a hot stock, beware: Private competitors may be a creeping risk. And those risks are not always spelled out in the risk-factor sections of SEC filings.

This is a theme I highlight every now and then. Last time I even used several of the same companies as examples. But as times goes on, the risks become greater.

Take Stereotaxis Inc. (STXS), which makes automated systems used by interventional cardiologists to control catheters and other devices sent through blood vessels. The company says in its 10-K it has no competitors with commercially available products. And it doesn't.

But it does have one private competitor with products awaiting FDA approval — something not mentioned in the annual filing. The company, Hansen Medical, was originally mentioned here as a competitor merely working on something similar. Its CEO is Frederick Moll, who was founder of Intuitive Surgical. As it turns out, Hansen and Intuitive, in fact, have cross-licensing agreements with one another.

Now Hansen is hoping to get regulatory approval of a robotically controlled version of a Stereotaxis competing system in the second half of this year, with hopes of a commercial rollout in the third quarter.

Then there's Foxhollow Technologies Inc. (FOXH), whose claim to fame is a device that removes plaque from leg vessels afflicted with peripheral arterial disease. In its 10-K, Foxhollow says it is aware of potential competition from "at least two other companies," Cardiovascular Systems and Pathway Medical, which are both private.

But it says nothing about privately held AngioScore, which unlike Cardiovascular and Pathways, has a product that has made its way through trials and is now starting to be rolled out commercially. AngioScore claims its product can treat peripheral arterial disease cheaper and faster than Foxhollow's approach.

Will doctors agree? Stay tuned.

P.S. Also keep an eye on privately held North Carolina's Aldagen. Its technology uses bone marrow to create stem cells that grow new vessels in the leg to circumvent those that are clogged. So far, results apparently have been encouraging, but the process may still be a few years from commercialization.

Meanwhile, back at the ranch: In light of the "60 Minutes" report Sunday on Biovail Corp's lawsuit against SAC Capital and Gradient Analytics — and Overstock's war against critics — I can't help but wonder what it would be like if Media Vision were happening today.

That was the big fraud I exposed in the pre-Internet early 1990s. Starting with a tip from short-sellers about funky financials, the Silicon Valley maker of multimedia kits became a near-daily fixture of my column in the San Francisco Chronicle. The more I wrote, the angrier CEO Paul Jain became. He even complained to my editor that I was ripping apart the fabric of everything that made Silicon Valley great — and that I was destroying jobs.

That was before Media Vision was deemed a major fraud, after I disclosed the company was booking revenue on completed products while parts for those supposedly completed products were (literally) on a slow boat from China. Jain and his CFO, Steven Allan, subsequently went to jail.

If this were today, would Jain have started an Internet-based campaign to intimidate the press, short-sellers and other critics — claiming a conspiracy? Would message boards be buzzing with "Get Herb Fired" posts? Would the company either by itself or with other companies be spinning the story every which way and suing its critics out of business and into silence?

Probably. But thankfully in those pre-Internet days, right beat financial might.

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