Obviousness

Obviousness (35 U.S.C. § 103)

To assess obviousness under 35 U.S.C. § 103, one must consider whether the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (PHOSITA). This involves identifying the scope and content of the prior art, ascertaining the differences between the prior art and the claims at issue, and resolving the level of ordinary skill in the pertinent art. Additionally, secondary considerations of non-obviousness, such as commercial success, long-felt but unsolved needs, and failure of others, can be considered.

The priority date for US12239333 is January 26, 2018.

Obviousness Arguments

Combination 1: U.S. Pat. No. 9,526,864 in view of US20220347455A1 (or other hemostasis valve prior art)

• U.S. Pat. No. 9,526,864: This patent, titled "RETRACTION AND ASPIRATION DEVICE FOR TREATING EMBOLISM AND ASSOCIATED METHODS," is explicitly incorporated by reference into US12239333. It discloses a retraction and aspiration device, catheter systems, and tubing systems for treating embolisms. The patent describes an RA device coupleable to a catheter system to simultaneously retract a portion of the catheter system and aspirate through it. The tubing system fluidly couples the pressure source of the RA device to the aspiration lumen of the catheter system, enabling material (e.g., blood and clot) to flow into the tubing system.
• US20220347455A1 (and related): This application, and its underlying provisional application (U.S. Provisional Application No. 62/554,931, filed Sep. 6, 2017), detail hemostasis valves and methods of use for sealing medical devices during intravascular access. These valves are designed to minimize blood loss, prevent air delivery into the vasculature, and maintain sterility. They can seal the lumen of a catheter when a tool extends through it or when no tool is present. The patent describes methods of advancing a tool through a delivery device with a hemostatic valve, and the tubular member of the valve collapsing on the shaft of the tool to seal around it. Other prior art such as WO2019055411A1 also describes hemostasis valves with seal members and plungers to open and close the seal. The Guardian Haemostasis Valve is another example of a hemostasis valve designed to minimize blood loss by maintaining a continuous seal during wire or microcatheter positioning.

Motivation for Combination:
A PHOSITA, seeking to improve the efficiency and safety of repeated interventional device passes for clot removal, would have been motivated to combine the retraction and aspiration system of U.S. Pat. No. 9,526,864 with the hemostasis valve technology known in the art, such as that described in US20220347455A1 (and related disclosures).

The U.S. Pat. No. 9,526,864 system aims to remove clot material and enable multiple passes. However, the background of US12239333 itself highlights a problem with existing devices: "if the once-deployed interventional device is reintroduced without fully removing and cleaning the catheter system, there is a significant risk that clot material and/or other contaminants from the catheter system will be reintroduced into the blood vessel of the patient during a second pass." This clearly identifies a problem that a PHOSITA would want to solve to facilitate safe, multiple passes without fully removing the guide catheter.

Hemostasis valves, as taught by US20220347455A1 and other references, are specifically designed to minimize blood loss and maintain sterility during catheter procedures, especially when devices are inserted or removed. A PHOSITA would recognize that incorporating a sophisticated hemostasis valve into the attachment member of the guide catheter in the U.S. Pat. No. 9,526,864 system would address the problem of preventing clot material from being stripped by the valve and subsequently reintroduced.

Specifically, the concept of a valve that can be unsealed (or opened) to facilitate withdrawal of the interventional device without stripping clot material (as in claims 1 and 9 of US12239333) and then resealed for subsequent aspiration is a logical evolution. U.S. Pat. No. 9,526,864 already discusses aspiration during retraction of the interventional device. Integrating a hemostasis valve that can be selectively opened (e.g., by an insert or actuation mechanism as taught by US12239333) to create a continuous lumen of consistent diameter for device withdrawal, and then resealed for effective aspiration, would be an obvious design choice to prevent clot stripping and reintroduction. The prior art on hemostasis valves already describes tubular members that collapse to seal and can be adjusted (e.g., via a tensioning mechanism or plunger) to allow passage of tools.

Therefore, a PHOSITA would be motivated to combine these references to create a system that allows for multiple, safe passes of an interventional device without requiring full removal of the guide catheter, by utilizing a hemostasis valve in the attachment member that can be manipulated to prevent clot stripping during device withdrawal and ensure effective aspiration.

Combination 2: U.S. Pat. No. 9,526,864 in view of US7018401B1 and general knowledge of aspiration thrombectomy.

• U.S. Pat. No. 9,526,864: As above, this patent describes a system for retraction and aspiration of clot material.
• US7018401B1: This patent discloses woven intravascular devices, including filters, and delivery systems for them. The delivery systems often involve two coaxial hollow tubes, where a device is secured between them. This patent also discusses a device being delivered over a guidewire using two coaxial tubes, where one end of the body is secured to the inner tube and the other to the outer tube.
• General Knowledge of Aspiration Thrombectomy: The field of thrombectomy, including aspiration techniques, was well-established prior to the priority date of US12239333. For example, the Penumbra's Indigo Aspiration system, launched in 2014, was marketed for thrombus removal from peripheral arteries and veins and for the treatment of PE. Devices such as the FlowTriever® Retrieval/Aspiration system (from the assignee Inari Medical Inc. itself) are indicated for non-surgical removal of emboli and thrombi from blood vessels through aspiration. The use of vacuum-assisted systems to treat pulmonary embolism was also known. WO2020036809A1 describes methods for intravascular treatment of clot material including positioning a catheter, coupling a pressure source via a valve, charging a vacuum while the valve is closed, and then opening the valve to apply the vacuum to aspirate clot.

Motivation for Combination:
A PHOSITA would readily combine the general principles of aspiration thrombectomy with the specific retraction and aspiration device described in U.S. Pat. No. 9,526,864. The need for efficient clot removal and the desire to minimize passes or improve the efficacy of each pass would motivate the PHOSITA to enhance the aspiration capabilities. The concept of using a "continuous lumen of generally constant diameter" through the attachment member (as claimed in US12239333 claim 16) to facilitate clot removal without stripping is a logical improvement given the known issues with clot fragmentation and re-embolization. US7018401B1, while not directly addressing hemostasis valves for multiple passes, highlights the use of coaxial tubes for device delivery and retrieval, which inherently suggests controlling the interaction between the device and the catheter lumen during withdrawal.

The idea of pre-charging a vacuum (as described in WO2020036809A1), then applying it instantaneously to generate greater suction forces (as described in US12239333, e.g., in block 1007 and 1406 of the methods), would be an obvious optimization to improve aspiration efficiency. This pre-charging technique, when combined with a system like U.S. Pat. No. 9,526,864 which already provides aspiration functionality, would lead to more effective removal of residual clot material, as highlighted as a benefit in US12239333.

The described benefits in US12239333 of preventing clot stripping and reintroduction by maintaining a constant diameter lumen during interventional device withdrawal are problems a PHOSITA would strive to solve, and the combination of existing aspiration techniques with well-understood catheter and valve designs would lead to the claimed inventions.