With more than 400 cases on file in the Cook Medical IVC Filter multidistrict litigation, plaintiffs’ lawyers and the defense are struggling to select bellwether cases for the upcoming trials.

Each party selected seven cases that they feel best represent most of the claims made in the lawsuits. However, the plaintiffs believe the defense has selected unrepresentative cases.

Two of the defense’s cases involve the Günther Tulip IVC Filter, but the majority of claims in the multidistrict litigation involve the Celect IVC Filter. While the plaintiffs acknowledge representation of claims specifically against Günther Tulip might be necessary, they recommend the selection of cases other than the two put forward by the defense.

Additionally, two cases involve recurrent deep vein thrombosis (DVT), a complication from IVC filters that isn’t present in a significant number of cases. To make matters worse, two more cases involve plaintiffs with preexisting clotting disorders. Plaintiffs claim the defense is only selecting cases where the plaintiffs either didn’t suffer significant injuries or had preexisting conditions to confuse the issues put forth in the litigation. But the defense didn’t take this lying down. They believe it’s the plaintiffs who have selected cases that misrepresent the litigation as a whole.

This isn’t the first time the two parties haven’t been able to agree. Lawyers for Cook asked for repeated postponements of the first trial to analyze cases for a possible settlement conference. No deal could reached, and so Cook decided to take these cases to trial.

Cook has been struggling with IVC filter lawsuits for four years, but it wasn’t until last summer that the lawsuits really began to gain serious momentum. In May 2015, Cook was facing 100 lawsuits. Just a month later, a study published in the Journal of Vascular Interventional Radiology found Cook’s devices caused perforation in 43% of patients. This caused a surge of lawsuits that are now plaguing Cook.

The stakes are high, but not just for Cook Medical. C.R Bard, Cordis Corporation, and Boston Scientific are also facing IVC filter lawsuits in the U.S. and Canada. The outcome in the Cook IVC filter litigation could set the tone for the remaining lawsuits.