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CAFC Affirms Claim Construction Driven by Patentee’s Clear Lexicography

11/4/2025
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Last week, the U.S. Court of Appeals for the Federal Circuit issued an opinion affirming the district court’s case-dispositive claim construction ruling in Aortic Innovations LLC v. Edwards Lifesciences Corporation, No. 2024-1145 (Oct. 27, 2025). 

Before the district court, the parties disputed the meaning of the term “outer frame” in the asserted independent claim of a patent directed to a dual-stage endovascular transcatheter valve assembly.  The district court construed the term to mean “a self-expanding frame.”  The accused device by Edwards Lifesciences used a single, balloon-expandable frame and had no self-expanding frame.  Based on the district court’s construction, the parties stipulated to non-infringement. Aortic appealed.

The Federal Circuit affirmed. Noting that a patentee’s written description of the invention is relevant and controlling “insofar as it provides clear lexicography[,]” and that an “‘implied redefinition must be so clear’ that a skilled artisan would understand ‘that it equates to an explicit one,’” the Court concluded that the patentee here had acted as its own lexicographer.  The Court explained that the shared specification of the asserted patents consistently referred to the structures identified as the “outer frame” in dual-frame embodiments as “self-expanding,” and used the terms “self-expanding frame” and “self-expanding outer frame” interchangeably.  The summary of the invention also described a transcatheter valve comprised of both a balloon-expandable frame and a self-expanding frame, and neither party had appealed the district court’s construction of “inner frame” to refer a “balloon-expandable frame.” 

The Court rejected the Aortic’s assertion that “outer frame” should be construed as “positioned outside,” cautioning that reading out the self-expanding aspect of the embodiments would ignore the specification’s lexicography. The Court further rejected Aortic’s argument that Edwards Lifesciences was judicially estopped from arguing in favor of the district court’s construction, determining the argument was forfeited because it was not developed before the district court.