CoviDien LP v. EtHICON Endo Surgery Inc

1. Case Identification

• Patent #: 8,317,070
• Filed: March 25, 2013
• Petitioner(s): Covidien LP
• Patent Owner(s): Ethicon Endo-Surgery, Inc.
• Challenged Claims: 1-14

2. Patent Overview

• Title: Surgical Stapling Instruments
• Brief Description: The ’070 patent is directed to surgical stapling instruments and cartridges capable of forming lines of staples with differing final formed heights. The claims require using staples that have different pre-deformation heights to achieve this outcome.

3. Grounds for Unpatentability

Ground 1: Claims 1-8 and 10-14 are anticipated by Holsten.

• Prior Art Relied Upon: Holsten (Application # 2007/0034666) and Robertson (Patent 5,964,394), which Petitioner argued is incorporated by reference in Holsten.
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Holsten discloses every element of the challenged claims. For claim 1, Holsten was alleged to teach a surgical stapling device with a circular anvil, a plurality of staples, and a staple driver assembly. Critically, Holsten allegedly discloses staples with different pre-deformation heights (e.g., fasteners 125a and 125b) that result in different formed staple lengths after actuation. For claim 8, Petitioner argued Holsten teaches a non-pivotable anvil. For limitations related to the staple driver mechanism, which are not explicitly shown in certain figures of Holsten, Petitioner contended that Holsten’s incorporation by reference of Robertson provides the necessary disclosure of staple pushers and a firing mechanism.

Ground 2: Claims 8 and 10-14 are anticipated by Pruitt.

• Prior Art Relied Upon: Pruitt (Patent 4,941,623).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Pruitt, a reference the Patent Owner acknowledged in the ’070 patent’s specification, anticipates all limitations of the claims directed to a non-pivotable anvil. Petitioner asserted that Pruitt discloses a surgical stapler with a non-pivotable anvil, a staple cartridge, and staple drivers. The petition highlighted that Pruitt explicitly teaches the use of a first quantity of staples (staples 7) with a different pre-deformation height than a second quantity of staples (staples 6). Upon actuation, these different staples necessarily result in different formed staple lengths, directly mapping onto the core limitations of the challenged claims.

Ground 3: Claims 1-7, 12, and 13 are obvious over Pruitt in view of Viola.

• Prior Art Relied Upon: Pruitt (Patent 4,941,623) and Viola (WO 2003/094747).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner contended that Pruitt discloses most elements of the challenged claims, including staples of varying pre-deformation heights, but teaches a linear stapler, not one with the claimed "circular anvil." Viola was asserted to remedy this deficiency by disclosing various types of staplers, including circular staplers, for procedures like end-to-end anastomoses. Viola also allegedly teaches other missing elements for certain dependent claims, such as a knife for cutting tissue (claim 7) and staple drivers arranged in rings (claim 2).
  • Motivation to Combine: A POSITA would combine Pruitt’s staple height variation mechanism with Viola’s circular anvil design to create a stapler for known surgical procedures requiring circular stapling (e.g., hemorrhoidal operations). The combination would allow the known benefit of differential staple heights (achieving better hemostasis across variable tissue thickness) to be applied in a circular stapling context.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because the combination involved applying a known feature (variable staple height) to a known device (a circular stapler) to achieve a predictable improvement in performance.

• Additional Grounds: Petitioner asserted numerous additional anticipation and obviousness challenges, including grounds where Viola was the primary reference anticipating most claims. Other grounds relied on combinations of Holsten or Pruitt with Burdorff (Patent 5,697,543) to teach a slideably movable anvil, with Conta (Patent 4,304,236) to teach circular anvils and knives, or with Iwabuchi (Japanese Application # 2001-87272) to further support the obviousness of using staples with different diameters. Extensive alternative grounds were also presented in case of different claim constructions, primarily by adding Green (Patent 3,494,533) to teach staples with prongs extending non-parallelly relative to each other.

4. Key Claim Construction Positions

• "two prongs extend non-parallelly from the main portion": Petitioner argued this phrase should be construed to mean the prongs extend non-parallelly relative to the staple's main portion (backspan), not non-parallelly relative to each other. This construction was asserted to be consistent with the specification (e.g., Fig. 12) and the prosecution history, and it facilitates mapping onto prior art where prongs are parallel to each other but perpendicular to the backspan.
• "formed staple length": Petitioner contended this term should be construed as "formed staple height." The argument was based on the specification and prosecution history, where the patentee allegedly used the terms "length" and "height" interchangeably when describing both pre-deformation and post-deformation staples.
• "non-pivotable anvil": Petitioner proposed this term be construed as "non-rotatable." The argument was that the specification uses "pivot" and "pivotally" to describe rotational movement (e.g., a trigger pivoting toward a grip), while describing the relevant anvil embodiment as "non-rotatable."

5. Key Technical Contentions (Beyond Claim Construction)

• Lack of Priority Claim: A central argument was that the ’070 patent is not entitled to the priority date of its parent, the ’562 application. Petitioner argued the ’562 application fails the written description requirement of §112 because its invention was expressly limited to using identically sized staples to achieve different formed heights. The parent application allegedly disclaimed the subject matter of the ’070 patent—using staples of different pre-deformation heights—by describing it as known, conventional prior art. Therefore, Petitioner contended the challenged claims’ effective priority date is the filing date of the ’070 patent application itself (February 28, 2007), which makes Holsten prior art under §102(a) and/or (e).

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-14 of the ’070 patent as unpatentable.