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Enborg v. Ethicon, Inc., 2022 U.S. Dist. LEXIS 51601 (E.D. Cal. March 21, 2022), is the pelvic mesh case of the week, and it involves a variety of plaintiff challenges to the defendant’s experts. That fact in itself is interesting. Usually it is the defense side that challenges expert opinions. Maybe the plaintiff side is smarting from the recent trend of defense verdicts in mesh cases. Desperate times call for desperate measures.

Several of the rulings in Enborg are common to numerous mesh decisions out there, but there is a favorable decision about Rule 30(b)(6) deposition testimony not being a judicial admission that we have not seen addressed before in any detail. Even in pelvic mesh world, there really can be new things under the sun. There is also a more detailed and nuanced discussion of challenges to a defense regulatory expert, particularly regarding testimony about testing, than is normally the case in mesh decisions.

The Enborg court ruled against the defendant on some issues, due to adverse (and awful) MDL decisions, but the defendant won more of these issues than is normally the case. Once again, remand courts facing actual trials tend to render better rulings than MDL courts that treat the litigation as a settlement mill. Finally, because warning claims were out of the case, a number of opinions were excluded as irrelevant.

Let’s get to the key rulings.

The plaintiffs tried to foreclose a defense materials expert from testifying that the mesh does not degrade in vivo. The court held that the defense expert identified the relevant data and appropriate methodology, so his opinions passed muster. But the plaintiff contended that those expert opinions should stay out of the case because a defense 30(b)(6) witness had testified that degradation can occur. The Enborg court rejected the plaintiff’s position, holding that the testimony by the 30(b)(6) representative was an evidentiary admission, not a judicial admission. The jury could hear both the 30(b)(6) and expert testimony and sort any possible conflict out for themselves. Moreover, the Enborg court reasoned that the expert’s opinion that the mesh was not suffering from any quantifiable degradation while in vivo was not necessarily in irreconcilable conflict with the 30(b)(6) testimony that surface degradation can occur. Consequently, the court denied the plaintiffs’ motion to exclude the expert testimony.

The defense also proffered a urogynecologist who would testify that the mesh implant did not cause the alleged injuries. The plaintiffs endeavored to shut down such testimony because the expert had last implanted the mesh device in question 15 years ago and most of his experience was with other devices. The court held that the expert had plenty of experience (200 implants) with the device and such experience, along with his education could support general causation opinions. Nevertheless, the court held that the urogynecologist’s “limited — and dated — clinical experience” with the device meant that he could not opine about specific issues of biocompatibility, degradation, pain, and erosion.

Another defense expert was an ob-gyn who had been retired since 2015. The plaintiffs argued that this expert had been out of the game too long and should not be permitted to testify about the device’s safety and efficacy, as well as the issue of degradation. The court held that the expert’s clinical experience and literature review made his opinions sufficiently reliable and sufficiently helpful for the jury.

The defense also sought to bring in an expert who would explain the 510(k) clearance process to the jury. As we have mentioned many times before, the problem is that the pelvic mesh MDL court made a hash out of the FDA 510(k) clearance issue, ruling that such clearance had nothing to do with safety and that any mention of it would confuse the jury. As the defendant argued in Enborg, the MDL court’s reliance on the SCOTUS Lohr opinion was misplaced. The Lohr case looked at unclassified, pre-1976 comparators that had undergone no safety review, whereas the post-1976, class II comparators used in securing 510(k) clearance for pelvic mesh had undergone safety screening. The defendant implored the Enborg court to “exercise its inherent authority to disagree with the MDL court.” Obviously, that is a tough ask. We have seen some mesh remand courts push back against the MDL 510(k) ruling after those courts see how the unfairness plays out in trial. The Enborg court was not prepared at this point to push back, but made its exclusion of 510(k) evidence “subject to the caveat that Plaintiffs do not seek to show that [the defendant] failed to comply with regulations pertaining to premarket review.” That is some consolation. Further, the Enborg court reserved ruling on whether the defense expert could opine that the particular mesh in question went through “a review process that is different from — and meaningfully more rigorous than — mere 510(k) clearance.”

There is fundamental unfairness if a plaintiff expert criticizes the extent of premarket mesh testing while the defense expert is muzzled from pointing out that the premarket mesh testing fully complied with 510(k) requirements. The plaintiff in Enborg seemed to be exploiting precisely that unfairness. The trick is for the plaintiff regulatory expert to say that the limited premarket testing fell short of industry, rather than regulatory, standards. To our eyes, the plaintiff expert was a wolf (regulatory) expert in a sheep (industry) expert disguise. Thus, the Enborg court was right to be suspicious, as it viewed the plaintiffs’ position “as something less than a full-throated renunciation of regulatory evidence as to the adequacy of premarket testing.” The Enborg court said that it will revisit this issue depending on where the plaintiff expert’s testimony goes. Will the plaintiff open the regulatory door? Heck, in our view, the moment the plaintiff expert discusses her qualifications she will blow the door off its hinges.