PTAB

IPR2018-01569

Cook Incorporated v. Medtronic Vascular Inc.

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1. Case Identification

2. Patent Overview

  • Title: Apparatus and Methods for Endoluminal Graft Placement
  • Brief Description: The ’427 patent relates to apparatus and methods for the endoluminal placement of grafts and stents to treat conditions such as abdominal aortic aneurysms. The disclosed methods involve introducing multi-component vascular grafts, including bifurcated structures and tubular grafts, into a patient's vasculature.

3. Grounds for Unpatentability

Ground 1: Claims 1-42 are obvious over Lazarus in view of Schaer.

  • Prior Art Relied Upon: Lazarus (Patent 5,871,536) and Schaer (a 1992 article titled "Treatment of Malignant Esophageal Obstruction With Silicone-Coated Metallic Self-Expanding Stents").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Lazarus disclosed a method for introducing a bifurcated vascular graft (with an anchor section and two leg-like connector sections) to repair aortic aneurysms. However, Lazarus also acknowledged that graft components may need to be adjustable to accommodate a patient's specific anatomy. Schaer taught the known technique of extending a first stented graft that is too short by introducing and deploying a second overlapping graft to achieve a desired total length. Petitioner contended that combining Lazarus's bifurcated graft with Schaer's overlapping extension technique renders the challenged claims obvious. Specifically, the method of claim 1—deploying a bifurcated structure and thereafter introducing first and second tubular grafts into the connector sections—was a direct application of Schaer's teaching to the system of Lazarus.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would be motivated to combine these references to solve the known clinical problem of improper graft sizing. A POSITA would have recognized the risk of sizing the Lazarus graft too short, which could result in an incomplete aneurysm exclusion. To mitigate this risk without resorting to more invasive open surgery, a POSITA would look to known, less invasive solutions. Schaer provided an obvious and routine solution: extending the legs of the Lazarus graft with overlapping tubular grafts to ensure a proper seal within the branch arteries.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because overlapping stents and grafts was a well-understood and common-sense technique used to extend stented regions. Applying this simple, predictable technique to the connector legs of the Lazarus graft would predictably result in a longer, properly-sealed bifurcated graft.

Ground 2: Claims 1-42 are obvious over Lazarus in view of Dumon.

  • Prior Art Relied Upon: Lazarus (Patent 5,871,536) and Dumon (Patent 5,236,446).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground focused on the method of assembling the graft in situ. Lazarus disclosed introducing a single-piece bifurcated graft and then performing a complex catheterization procedure to maneuver the second leg across the vessel bifurcation into the contralateral branch artery. Dumon, in contrast, disclosed a simpler method of forming a bifurcated endoprosthesis by separately introducing and deploying multiple components to build the final structure in situ. Petitioner argued it would be obvious to apply Dumon's simpler, modular assembly method to the type of bifurcated graft taught by Lazarus.
    • Motivation to Combine: A POSITA would be motivated to simplify the complex and technically demanding procedure described in Lazarus. The Lazarus method of pulling a graft leg across the aortic bifurcation presented risks of kinking or twisting the graft, potentially occluding blood flow. Dumon taught a simpler, easier, and safer alternative of building the bifurcated structure from individual components introduced separately. A POSITA would thus combine the Lazarus graft structure with the Dumon modular assembly method to improve the safety and simplicity of the procedure.
    • Expectation of Success: The modular technique from Dumon was a known approach for creating bifurcated structures in anatomical conduits. Applying this technique to the vascular environment using the components described in Lazarus was a predictable application of a known method to a similar problem (creating a bifurcated flow path), and thus a POSITA would expect it to succeed.

4. Key Claim Construction Positions

  • "Simultaneously": Petitioner argued that certain dependent claims require anchoring a graft "simultaneously" in a connector and a branch artery. As the patent specification does not disclose instantaneous expansion at both ends of a graft, Petitioner asserted a POSITA would understand this term to mean "in the same procedural step" (e.g., releasing the graft from a single delivery sheath), rather than at the exact same moment in time.
  • "Introducing": Petitioner argued that for independent claim 15, the step of "introducing...an anchor section and first tubular graft" does not require they be introduced in a single step or simultaneously. Based on the prosecution history, Petitioner contended this term should be broadly construed to mean introducing the components "in one or more steps."

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that the Board should not exercise its discretion to deny institution under §325(d), even though the primary references (Lazarus, Schaer, and Dumon) were cited to the Patent Office during prosecution. Petitioner contended that these references were merely listed in a lengthy Information Disclosure Statement (IDS) and were not substantively addressed, analyzed, or applied against the claims by the Examiner. Therefore, the Examiner never considered the specific obviousness combinations and arguments presented in the petition.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-42 of the ’427 patent as unpatentable under 35 U.S.C. §103.