Federal Circuit Expands Prosecution History Estoppel to Simple Claim Cancellations in Colibri Heart Valve

by Dennis Crouch

In a decision that broadens the reach of prosecution history estoppel (and thus limits doctrine of equivalents), the Federal Circuit reversed a $106 million jury verdict in Colibri Heart Valve LLC v. Medtronic CoreValve, LLC, No. 2023-2153 (Fed. Cir. July 18, 2025). The court held that prosecution history estoppel barred Colibri from asserting doctrine of equivalents infringement based solely on the cancellation of a broad claim during prosecution—even though the asserted claim itself was original and never amended. This represents a notable, but not surprising, expansion of estoppel doctrine beyond traditional claim amendments to encompass strategic claim cancellations that communicate narrowing to persons of ordinary skill in the art. [23-2153.OPINION.7-18-2025_2546584]