Colibri Heart Valve LLC v. Medtronic CoreValve, LLC, decided July 18, 2025

Court: United States Court of Appeals for the Federal Circuit Case Number: 2023-2153 Decided: July 18, 2025 Appeal From: United States District Court for the Central District of California, No. 8:20-cv-00847-DOC-JDE, Judge David O. Carter.

I. Executive Summary

The Federal Circuit reversed the District Court's denial of Medtronic CoreValve, LLC's (Medtronic) motion for judgment as a matter of law (JMOL) of noninfringement. The central issue revolved around U.S. Patent No. 8,900,294 (the ’294 patent), owned by Colibri Heart Valve LLC (Colibri), which claims a method for implanting an artificial heart valve with a "do-over" opportunity, allowing partial deployment and recapture if positioning is incorrect.

Colibri sued Medtronic for inducing surgeons to infringe the ’294 patent using Medtronic’s Evolut products. While Colibri initially alleged literal infringement, it ultimately relied solely on the doctrine of equivalents. The jury found in favor of Colibri, awarding over $106 million in damages.

On appeal, Medtronic argued, among other things, that Colibri's equivalents claim was barred by prosecution history estoppel. The Federal Circuit agreed, finding that Colibri's cancellation of a specific claim (claim 39) during patent prosecution, which described partial deployment by "retracting" the moveable sheath, created an estoppel. Despite Colibri's assertion that its claimed method involved "pushing out the pusher member from the moveable sheath," and Medtronic's method involved "retracting the moveable sheath," the court determined that, based on "simple physics" and Colibri's own arguments for equivalence, both methods inherently required a pushing force acting against a retraction. Therefore, the cancellation of the "retracting" claim constituted a narrowing amendment, precluding Colibri from asserting infringement under the doctrine of equivalents for methods involving retraction.

This reversal on the issue of noninfringement mooted Medtronic's other challenges, including invalidity and damages, as the ’294 patent has already expired.

II. Key Parties and Patent

• Plaintiff-Appellee: Colibri Heart Valve LLC

• Patent in Suit: U.S. Patent No. 8,900,294 ("Method of Controlled Release of a Percutaneous Replacement Heart Valve")

• Key Claim (Claim 1): Describes a method of controlled heart valve release, including a step of "partially deploying a distal portion of the replacement heart valve device within the patient by pushing out the pusher member from the moveable sheath to expose the distal portion." This allows for recapture if positioning is incorrect.

• Defendant-Appellant: Medtronic CoreValve, LLC

• Accused Product: Evolut line of replacement heart valves.

• Accused Method: Involves partially deploying the valve by retracting the moveable sheath, while applying a pushing force to hold the stent in place. This method also allows for recapture.
  

III. Background of the Dispute

A. The ’294 Patent and Colibri's Method

• The ’294 patent, which expired in January 2022, focuses on artificial heart valves and their implantation.

• The patented method allows for a "do-over opportunity" during implantation. The valve is partially deployed from a delivery apparatus, and if positioning is off, it can be recaptured before full deployment.

• Original Prosecution: The patent initially included two independent claims for the do-over method: one for partial deployment by pushing the valve out and one for retracting the outer sheath. The "retracting" claim (claim 39) was rejected for lack of written description and subsequently cancelled by Colibri. The patent issued with claims reciting partial deployment by pushing, specifically claim 1.
  

B. Medtronic's Accused Products and Method

• Medtronic sells the "Evolut" line of replacement heart valves.

• The Evolut products can also be "recaptured" during implantation.

• Deployment Mechanism: The Evolut implantation involves a catheter with a moveable sheath. Rotating a deployment knob retracts the moveable sheath, uncovering (deploying) the valve. Rotating it the other way recaptures the valve.
  

C. District Court Proceedings

• Lawsuit: Colibri sued Medtronic in May 2020 for infringement of the ’294 patent. Colibri initially asserted direct, contributory, and inducement of infringement, but later pursued only inducement of infringement.

• Claim Construction: The parties disputed the meaning of "pushing out the pusher member from the moveable sheath." The district court adopted Medtronic’s proposed construction, meaning "pressing against the pusher member with a force that moves the pusher member out of the moveable sheath."

• Summary Judgment: Medtronic argued that prosecution history estoppel barred Colibri's doctrine of equivalents claim, specifically due to the cancellation of claim 39 (the "retracting" claim). The special master and district court rejected this, reasoning that claim 39 was a "separate independent claim" from claim 1, and Colibri's "asserted equivalent is not merely retraction" but a combination of pushing and retracting.

• Trial and Verdict: Colibri abandoned its literal infringement theory, relying solely on the doctrine of equivalents. It argued that Medtronic's partial-deployment method (applying a force to hold the stent while retracting the sheath) was equivalent to the claimed "pushing out" method. The jury found Medtronic induced infringement and awarded Colibri over $106 million.

• Post-Trial Motions: Medtronic filed renewed motions for JMOL, again asserting prosecution history estoppel. The district court denied these motions, reiterating its prior reasoning.
  

IV. Federal Circuit Appeal and Ruling

A. Jurisdiction and Standard of Review

• The Federal Circuit had jurisdiction under 28 U.S.C. § 1295(a)(1).

• Review of the district court’s JMOL decision followed the Ninth Circuit’s de novo standard, with deference to jury findings on fact issues.

• Crucially: Prosecution history estoppel is a matter of law, reviewed de novo by the Federal Circuit.
  

B. Waiver Argument (Medtronic's Prosecution History Estoppel Defense)

• Colibri argued Medtronic waived its prosecution history estoppel argument due to a pre-trial statement.

• The Federal Circuit rejected the waiver argument for three reasons:

• Medtronic's statement could be interpreted as not pursuing the argument before the jury, given it was a question of law already rejected at summary judgment. Medtronic also disclaimed waiver in the same document.

• Medtronic explicitly made the estoppel argument in its Rule 50(a) motion during trial, and Colibri responded on the merits, not by claiming waiver.

• Colibri raised the waiver argument for the first time in its opposition to Medtronic's Rule 50(b) motion, and the district court addressed the merits without suggesting waiver or prejudice.
  

C. Merits: Prosecution History Estoppel

The Federal Circuit focused solely on prosecution history estoppel to resolve the appeal.

1. Asserted Equivalent's Relationship to Cancelled Claim 39:

2. The district court and special master erred in concluding that Colibri's asserted equivalent (Medtronic's method) "differs distinctly from what was recited in cancelled claim 39."

3. Colibri's "Simple Physics" Argument: Colibri's own theory of equivalence hinged on "simple physics" or "basic physics," arguing that "opposing forces (i.e., pushing and retracting) be applied to deploy the valve and stent from the moveable sheath." Colibri consistently asserted that "pushing necessarily accompanies retracting" because of the stent's radial force.

4. Claim Language Support: Both claim 1 and cancelled claim 39 state that the device is "restrained in the collapsed configuration by the moveable sheath." This implies that without a pushing force, retracting the sheath would also retract the stent. Therefore, a "countervailing pushing force is necessary to both Colibri’s asserted equivalent and the deployment method described by claim 39."

5. Narrowing Amendment and Estoppel:

6. The court agreed with Medtronic that Colibri's cancellation of claim 39 constituted a narrowing amendment, giving rise to prosecution history estoppel.

7. Formalism vs. Substance: The district court's rationale (that claim 39 and claim 1 were separate independent claims and no amendments were made to claim 1) was deemed overly formalistic.

8. Governing Law:Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co. emphasized that estoppel arises when an amendment "narrows the patent's scope" or when "the patentee narrowed his claims to obtain the patent." This is not limited to direct amendment of the asserted claim.

9. Schriber-Schroth Co. v. Cleveland Trust Co. established the principle that allowed claims "must be read and interpreted with reference to claims that have been cancelled or rejected" and "cannot by construction be read to cover what was thus eliminated from the patent."

10. Honeywell International Inc. v. Hamilton Sundstrand Corp. rejected a formalistic approach, holding that rewriting dependent claims into independent form (without changing their scope) could still create estoppel if the overall scope of claimed subject matter was narrowed to secure the patent.

11. Other Federal Circuit precedents (e.g., Glaxo Wellcome, Inc., Deering Precision Instruments, L.L.C.) support that subject matter surrendered via amendments applies to other claims containing the same limitation.

12. Substantive Relationship: The court found a "close substantive relationship" between cancelled claim 39 (retracting) and retained claim 1 (pushing), as Colibri's own "basic-physics logic" for equivalence demonstrated their intertwined nature. A "skilled artisan reading the prosecution history would understand that some narrowing had occurred through cancelling claim 39."

13. Conclusion: The cancellation of claim 39, despite being a separate independent claim, communicated a narrowing message about the scope of the retained claim 1, especially given the "close basic-physics relationship" between "pushing" and "retracting" in this context.
    

V. Ruling and Implications

• The Federal Circuit reversed the district court’s denial of JMOL of noninfringement.

• This reversal meant Medtronic was entitled to judgment of noninfringement as a matter of law.

• The decision mooted all other aspects of Medtronic’s appeal, including invalidity and damages, as the ’294 patent had already expired.

• Public Notice Function: The court underscored that this ruling served the "public-notice function of prosecution history estoppel," ensuring that the public can rely on the scope of claims as defined by the prosecution record. If Colibri desired to cover retraction methods outside the literal scope of claim 1, it should have pursued it through other means, such as a continuation application.