DEAR DOCTOR LETTERS
Solutions (“Ascent”) for reprocessing, so that it could be used in another
patient (ultimately, plaintiff).100
We focus on the district court’s grant of full summary judgment to
Biosense (Ascent was left in the case), and in particular on the analysis of
plaintiff’s failure-to-warn claim. Plaintiff argued that Biosense’s catheter
was defective because: (1) it lacked adequate warnings about the risk of
mitral-valve entrapment, and (2) it lacked adequate instructions about how
to extricate an entrapped catheter.101 Plaintiff’s warning-defect claim was
not based on Biosense’s instructions for use—plaintiff’s expert admitted,
“doctors don’t read [instructions for use] in great detail every time.”102
Rather, plaintiff’s expert opined that Biosense should have warned about
mitral-valve entrapment in a Dear Doctor letter, which would say, “Dear
Doctor, we have had a few reports of entrapment of this catheter in the
mitral valve. Please be very careful with its use in the atrium, et cetera, et
The district court gave a free pass to plaintiff on the issue of whether he
could show that Biosense should have issued a Dear Doctor letter, as
opposed to inserting the proposed warning in the catheter’s instructions for
use.104 Plaintiff’s warning expert testified that there are “probably some”
Dear Doctor letter regulatory requirements, but didn’t “know them” and
couldn’t “quote them.”105 (As shocking as this may seem, many warning-defect experts are unfamiliar, not only with Dear Doctor letter regulations,
but FDA labeling regulations more generally—a fruitful subject for a
Daubert motion106 to exclude a plaintiff’s warning-defect expert.) Because
neither party briefed Dear Doctor Regulations, the district court did not
make a ruling on the subject.
The District Court of Minnesota assumed, “for the sake of argument”
that Biosense could have issued the warning advocated by the plaintiff.107
Had Biosense analyzed the “important” information standard and categories
100. Id. at 1134.
101. Id. at 1155. Plaintiff also argued that Biosense failed to warn of the dangers
associated with reprocessing. Id. However, the court easily dismissed this argument, in light
of Biosense’s clear instruction to use the catheter only once. The court found it “fanciful” to
suggest that Biosense has a further duty to tell doctors, in effect, “Our catheters are labeled
for a single use. We really mean it. Some companies will offer to reprocess our catheters.
Those companies will tell you that the reprocessed catheters are safe. Don’t believe them.”
Id. at 1158-59.
102. Id. at 1155 (internal quotations and citation omitted).
104. Id. at 1156.
106. Daubert v. Merrill Dow Pharms., Inc., 509 U.S. 579 (1993).