Catheter recall - tip detachment due to embrittled material

Boston Scientific is getting a bit of attention for an IVUS catheter Class I recall, to be honest a smaller company probably wouldn't get the same attention.  What I thought was interesting was that they published a rate for the catheter tip detachment, from Cardiovascular Business:

The corrective action, announced May 27, is being taken due to eight confirmed cases of catheter tip detachments caused by the embrittlement of catheter material. The Natick, Mass.-based company confirmed a rate of 0.027 percent of catheter tip detachments in the U.S. and Puerto Rico from April 1, 2010, to May 10, 2011.

I don't think I've seen a rate published before and a quick search didn't turn up anything.  Presumably this is their complaint rate, of 0.027% or about 1 in 3700, so their recall of 30,000 devices prevented 8 tip detachments.  No more details are available, so we don't know if it is a design issue or a manufacturing issue, although an "embrittlement of catheter material" sounds like a design issue- but it is not impossible to imagine something done incorrectly in manufacturing that could cause this.  That being said, storage conditions or sterilization effects (if it is not EtO) would be where I would start.

From a risk point of view, if there is one thing you don't want to happen is for parts of a catheter to fall off inside of someone, the severity is obviously high.  Tip detachment is generally detectable at least when you remove the catheter from the body, if not sooner, depending if the part detaching is radiopaque or if the catheter stops functioning when the tip detaches.  In this case the bar has been set, a rate of 0.027% is too high, which I would agree with, especially for a large company and this type of diagnostic device with suitable alternate diagnostic methods available.  Boston Scientific is doing the right thing with the recall and hopefully they are able to address the issue and move on.

SonoChief predicts the costs of the recall:

Boston Scientific’s voluntary recall of the iCross Coronary Imaging Catheters will be disruptive to their ultrasound division. With an average street price of  [private]$800 dollars a recall of nearly 30,0000 catheters equates to a loss of 2.4 million inventory.
...
Boston Scientific customers are being told all iCross Coronary Imaging Catheters are being replaced with Atlantis SR Pro Coronary Imaging Catheters, which will operate with Boston Scientific’s IVUS imaging consoles and are immediately available.  The Company does not expect this recall to have a material financial impact.

Which is actually $24 million (incorrectly multiplied above), if you use street value, but presumably Boston has a margin of 60% or more, and no one buys list price, which would put the cost closer to $4 million.  Although the recall is being expanded beyond the original 30,000 catheters.  The cost to their reputation as competitors gain is obviously significantly higher.

I'm not sure what the take away from this is other than do a thorough job on your verification testing, Boston Scientific surely documented and tested for the tip detachment risks and thought they were acceptable, but the rate came out higher than predicted.  I would like to know the material and conditions that lead to the issue, I have a few guesses, but its doubtful we'll ever see that level of detail.