Triever Duo Catheter

{0} **FDA** U.S. FOOD & DRUG ADMINISTRATION September 18, 2026 Inari Medical, Inc. Anthony Lam Manager, Regulatory Affairs 6001, Oak Canyon Suite 100 Irvine, California 92618 Re: K253419 Trade/Device Name: Triever Duo Catheter Regulation Number: 21 CFR 870.5150 Regulation Name: Embolectomy Catheter Regulatory Class: Class II Product Code: QEW, KRA, DQO Dated: September 14, 2026 Received: September 15, 2026 Dear Anthony Lam: We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading. If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of {1} K253419 - Anthony Lam Page 2 Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register. Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download). Your device is also subject to, among other requirements, the Quality Management System Regulation (QMSR) (21 CFR Part 820), which includes, but is not limited to, ISO 13485 clause 7.3 (Design controls), ISO 13485 clause 8.3 (Nonconforming product), ISO 13485 clause 8.5.2 (Corrective action), and ISO 13485 clause 8.5.3 (Preventative action). Please note that regardless of whether a change requires premarket review, the QMSR requires device manufacturers to review and approve changes to device design and production (ISO 13485 clause 7.3 and ISO 13485 clause 7.5) and document changes and approvals in the Medical Device File (ISO 13485 clause 4.2.3). Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the Quality Management System Regulation (QMSR) (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050. All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems. For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn {2} K253419 - Anthony Lam Page 3 (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100). Sincerely, KRINA M. PATEL -S Digitally signed by KRINA M. PATEL -S Date: 2026.09.18 11:05:37 -04'00' For, Gregory O'Connell Assistant Director DHT2C: Division of Coronary and Peripheral Intervention Devices OHT2: Office of Cardiovascular Devices Office of Product Evaluation and Quality Center for Devices and Radiological Health Enclosure {3} | Indications for Use | | | | --- | --- | --- | | Please type in the marketing application/submission number, if it is known. This textbox will be left blank for original applications/submissions. | K253419 | ? | | Please provide the device trade name(s). | | ? | | Triever Duo Catheter | | | | Please provide your Indications for Use below. | | ? | | The FlowTriever Retrieval/Aspiration System is indicated for: • The non-surgical removal of emboli and thrombi from blood vessels. • Injection, infusion, and/or aspiration of contrast media and other fluids into or from a blood vessel. The FlowTriever Retrieval/Aspiration System is intended for use in the peripheral vasculature and for the treatment of pulmonary embolism. The Triever Duo, a Triever Catheter within the FlowTriever Retrieval/Aspiration System, is indicated for: • Treating clot in transit in the right atrium, but not in conjunction with FlowTriever Catheters. • Pressure Measurement | | | | Please select the types of uses (select one or both, as applicable). | ☑ Prescription Use (21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C) | ? | {4} K253419 Page 1 of 8 ## 510(K) SUMMARY | Date prepared | September 17, 2026 | | --- | --- | | Name | Inari Medical, Inc. 6001 Oak Canyon, Suite 100 Irvine, CA 92618 877.923.4747 | | Contact person | Anthony Lam Manager, Regulatory Affairs | | Trade name | Triever Duo Catheter | | Common name | Embolectomy Catheter | | Regulation name | Embolectomy Catheter | | Classification number | 21 CFR 870.5150 | | Product code | QEW, KRA, DQO | | Regulatory class | II | | Predicate device | Triever24 Catheter (K213402) | | Reference device | Langston Dual Lumen Catheter (K221470) | | Description | The FlowTriever Retrieval/Aspiration System is a single-use, sterile medical device designed for use in the peripheral vasculature. The Triever Duo is a Triever Catheter within the FlowTriever Retrieval/Aspiration System. The Triever Duo Catheter consists of a catheter and dilator. The dilator assists in its advancement over a pre-placed 0.035" guidewire to the proximal end of the thrombus using fluoroscopic visualization. The Triever Duo Catheter and dilator are inserted through an introducer sheath (not provided). After Triever Duo Catheter placement, the dilator is detached from the hemostasis valve and removed from the patient. The catheter is comprised of a dual lumen catheter, a proximal hemostasis valve to minimize blood loss, a stopcock with flush port, and a secondary lumen sideport. The main lumen can be used as a conduit for the FlowTriever Catheters, FlowTriever2, Triever20 Curve, Triever16 Curve, and Triever16. The thrombus may also be aspirated by attaching the Large Bore 60 cc Syringe to the Triever Duo Catheter's main lumen sideport quick-connect. The secondary lumen has a luer connection on the sideport which allows for the infusion of liquids, as well as the ability to be attached to a pressure measuring device (not included) for simultaneous pressure measurement during the thrombectomy procedure. | | Indications for Use | The FlowTriever Retrieval/Aspiration System is indicated for: - The non-surgical removal of emboli and thrombi from blood vessels. - Injection, infusion, and/or aspiration of contrast media and other fluids into or from a blood vessel. | {5} K253419 Page 2 of 8 The FlowTriever Retrieval/Aspiration System is intended for use in the peripheral vasculature and for the treatment of pulmonary embolism. The Triever Duo, a Triever Catheter within the FlowTriever Retrieval/Aspiration System, is indicated for: - Treating clot in transit in the right atrium, but not in conjunction with FlowTriever Catheters. - Pressure Measurement. Summary of substantial equivalence A tabular comparison of the predicate and subject devices is provided below: | | **Subject Device** Triever Duo Catheter | **Primary Predicate Device** Triever24 Catheter | **Reference Device** Langston Dual Lumen Catheter | | --- | --- | --- | --- | | **510(k) Number** | K253419 | K213402 | K221470 | | **Manufacturer** | Inari Medical, Inc. | Inari Medical, Inc. | Vascular Solutions, LLC. | | **Regulations** | 21 CFR 870.5150 Embolectomy Catheter | 21 CFR 870.5150 Embolectomy Catheter | 21 CFR 870.1200 Diagnostic Intravascular Catheter | | **Product Code** | QEW, KRA, DQO | QEW, KRA | DQO | | **Intended Use/Indications for Use** | The FlowTriever Retrieval/Aspiration System is indicated for: - The non-surgical removal of emboli and thrombi from blood vessels. - Injection, infusion, and/or aspiration of contrast media and other fluids into or from a blood vessel.The FlowTriever Retrieval/Aspiration System is intended for use in the peripheral vasculature and for the treatment of pulmonary embolism. The Triever Duo, a Triever Catheter within the FlowTriever Retrieval/Aspiration System, is indicated for: - Treating clot in transit | FlowTriever Retrieval/Aspiration System is indicated for: - The non-surgical removal of emboli and thrombi from blood vessels. - Injection, infusion, and/or aspiration of contrast media and other fluids into or from a blood vessel.The FlowTriever Retrieval/Aspiration System is intended for use in the peripheral vasculature and for the treatment of pulmonary embolism. Triever Catheters are also intended for use in treating clot in transit in the right atrium, but not in conjunction with FlowTriever Catheters. | Each Langston dual lumen catheter is indicated for delivery of contrast medium in angiographic studies and for simultaneous pressure measurement from two sites. This type of pressure measurement is useful in determining transvalvular, intravascular and intraventricular pressure gradients. | {6} K253419 Page 3 of 8 | | in the right atrium, but not in conjunction with FlowTriever Catheters. • Pressure Measurement. | | | | --- | --- | --- | --- | | **Device Description** | The Triever Duo Catheter is comprised of a dual lumen catheter with a hemostasis valve integrated into the proximal hub to minimize blood loss, a stopcock with flush port, and a secondary lumen sideport. A radiopaque marker is positioned near the distal tip of the catheter to aid with fluoroscopic visualization. The main lumen, which extends the entire length of the catheter, provides access for the FlowTriever Catheters, FlowTriever2, Triever20 Curve, Triever16 Curve, and Triever16, to the treatment site and provides a large lumen for the aspiration of clot using the Large Bore 60 cc Syringe. The main lumen sideport tube has a terminal quick connect coupling to allow connection for flushing or aspiration of thrombus. The secondary lumen, which ends proximal to the distal end of the catheter, has a luer connection on the sideport which allows for the infusion of liquids, as well as the ability to be attached to a pressure monitoring device (not included) to allow physicians to monitor pressure measurement. The Triever Duo dilator is compatible with a 0.035” | The Triever24 Catheter is comprised of a single lumen catheter with a hemostasis valve integrated into the proximal hub to minimize blood loss and a stopcock with flush port. A radiopaque marker is positioned near the distal tip of the catheter to aid with fluoroscopic visualization. The lumen provides access for the FlowTriever Catheters and other compatible devices to the treatment site and provides a large lumen for the aspiration of clot using the Large Bore 60 cc Syringe. The sideport tube has a terminal quick connect coupling to allow connection for flushing or aspiration of thrombus. The Triever24 dilator is compatible with a 0.035” guidewire and has a tapered atraumatic tip, which aids in insertion and positioning of the catheter. | The Langston dual lumen catheters have two lumens, both with distal sideholes, to allow simultaneous pressure measurements from two sites. The high-pressure inner lumen, which extends the entire length of the catheter, can be used for pressure measurement and rapid delivery of contrast medium. The outer lumen ends proximal to the distal end of the catheter and is used for pressure measurement only. A side port fitted with an extension tube and a stopcock assembly is used for fluid flow and pressure measurement within the outer lumen. The Langston dual lumen catheter will accommodate a ≤ 0.038” diameter guidewire and is supplied with a single use pigtail straightener. | {7} K253419 Page 4 of 8 | | guidewire and has a tapered atraumatic tip, which aids in insertion and positioning of the catheter. | | | | --- | --- | --- | --- | | Principles of Operation | The Triever Duo Catheter is placed over a 0.035" guidewire to a location proximal of the target thrombus. The radiopaque marker is positioned near the distal tip to aid with fluoroscopic visualization. The Triever Duo Catheter secondary lumen allows for the infusion of liquids, as well as the ability to be attached to a pressure measuring device (not included) for simultaneous pressure measurement during the thrombectomy procedure. The main lumen can be used as a conduit for the FlowTriever Catheters, FlowTriever2, Triever20 Curve, Triever16 Curve, and Triever16. The side port tube has a terminal quick release coupling to allow connection for flushing or aspiration of thrombus. Thrombus is aspirated by attaching the Large Bore 60 cc Syringe to the Triever Duo Catheter's sideport connector. | The Triever24 Catheter is placed over a 0.035" guidewire to a location proximal of the target thrombus. The radiopaque marker is positioned near the distal tip to aid with fluoroscopic visualization. The Triever24 Catheter lumen can be used as a conduit for the FlowTriever & FlowTriever2 Catheters. The side port tube has a terminal quick release coupling to allow connection for flushing or aspiration of thrombus. Thrombus is aspirated by attaching the Large Bore 60 cc Syringe to the Triever Catheter's side port connector. | The Langston dual lumen catheter is deployed over a standard ≤ 0.038" diameter guidewire and through a standard introducer sheath of appropriate size to the proper location. The Langston catheter consists of an inner braided high-pressure lumen which extends the entire length of the catheter, which can be used for pressure measurement and rapid delivery of contrast medium and an outer lumen that ends approximately 3cm-15cm proximal to the distal end of the catheter with sideholes for pressure measurement only. The inner and outer lumens are joined together using an adapter junction placed at the proximal end of the catheter. The adapter junction also incorporates a side port fitted with an extension tubing and a stopcock assembly for fluid flow and pressure measurement within the outer lumen. | | Target Vessel | Peripheral vessels ≥ 9.0 mm, pulmonary vasculature | Peripheral vessels ≥ 8.0 mm, pulmonary vasculature | Heart | | Catheter Materials | Stainless steel coil with Pebax and TPU outer cover, and PTFE inner liner. | Stainless steel coil with Pebax outer cover and PTFE inner liner. | Unknown | {8} K253419 Page 5 of 8 | **Number of Lumens** | 2 | 1 | 2 | | --- | --- | --- | --- | | **Catheter OD** | 26 Fr / 8.9 mm (0.350” Max) | 24 Fr / 7.9 mm (0.311” Max) | 6 Fr / 2 mm (0.079”) | | **Main Lumen ID** | 6.9 mm (0.272”) | 6.9 mm (0.272”) | 1.4 mm (0.0540”) | | **Secondary Lumen Dimension** | Cross sectional area: 0.0054 in² | N/A | 3 Fr (0.039”), Cross sectional area: .0012 in² | | **Effective Length** | 89 cm | 90 cm | 100 cm – 125 cm | | **Marker Band** | One (1) located at distal tip | One (1) located at distal tip | Five (5) marker bands 1 cm apart, located at the distal tip | | **Valve** | User actuated hemostasis valve. Internal polyblend tube that expands once the spring-loaded buttons are compressed creating an open pathway for guidewire and device insertion and withdrawal. | User actuated hemostasis valve. Internal polyblend tube that expands once the spring-loaded buttons are compressed creating an open pathway for guidewire and device insertion and withdrawal. | N/A | | **Dilator OD** | 0.266” | 0.266” | N/A | | **Dilator Shaft Material** | Pebax 35D, Pebax 45D, Pebax 55D with Propell | Pebax 35D, Pebax 45D, Pebax 55D with Propell | N/A | | **Dilator Tip** | Tapered | Tapered | N/A | | **Sterilization** | SAL 10⁻⁶, EO | SAL 10⁻⁶, EO | SAL 10⁻⁶, EO | | **Shelf-life** | 6 months | 24 months | Unknown | | **Guidewire compatibility** | 0.035” | 0.035” | ≤ 0.038” | | **Placement duration** | < 24 hours | < 24 hours | < 24 hours | | **Single-use** | Yes | Yes | Yes | {9} K253419 Page 6 of 8 ## Biocompatibility The following biocompatibility tests were completed for the subject device: - Cytotoxicity - Sensitization - Intracutaneous Reactivity - Acute Systemic Toxicity - Material-Mediated Pyrogenicity - Genotoxicity (Ames Assay and Mouse Lymphoma Mutagenesis Assay) - Hemocompatibility (Hemolysis, Complement Activation, Thromboresistance, Platelet and Leukocyte Count, and Partial Thromboplastin Time) - Chemical Characterization (3 Solvent / HRAM Analysis) The passing results demonstrate that the subject device and accessories meet biological safety requirements per ISO 10993-1. ## Sterilization The subject device, including its accessories, is sterilized using EO to achieve a sterility assurance level (SAL) of 10⁻⁶ using a validated sterilization process in accordance with the principles of ISO 11135:2014/Amd 1:2018 and AAMI TIR 28:2016. ## Electromagnetic Compatibility and Electrical Safety Evaluation The Triever Duo was evaluated in conjunction with pressure measuring devices against the CF applied parts and defibrillation proof applied parts IEC 60601-1 Ed 3.2 and IEC 60601-1-2 Ed 4.1 requirements. The pressure measuring devices shall be applicable for use in a hospital environment by trained physicians. ## Non-Clinical Testing In accordance with the Design Failure Modes and Effects Analysis, verification and validation tests were identified to support the substantial equivalence of the Triever Duo Catheter to the predicate device. These tests included: ### Verification Tests - Pouch Seal Visual Inspection - Bubble Leak - Dye Penetration - Pouch Seal Strength - Packaging Device Retention - Catheter Visual Inspection - Catheter Dimensional Inspection - Sheath Compatibility - Dilator Visual Inspection - Dilator Dimensional Inspection {10} K253419 Page 7 of 8 - Locking Cap Engagement Force and Unlocking Cap Torque - Guidewire Compatibility – Dilator - Device Priming - Insertion/Removal Force of Dilator through Catheter - Retraction Force of Self-Expanding Wireform Catheter - Catheter Kink Radius and Simulated Use Torque - Kink Radius and Triever20 Curve Compatibility - Air Leak Testing, Main Lumen - Air Leak Testing, Secondary Lumen - Leak Testing, Main Lumen - Leak Testing, Secondary Lumen - Vacuum Testing - Aspiration Flow Rate Testing - Pressure Measurement Accuracy - Infusion Testing - Torque and Tensile Testing - Engaged Axial Detachment Force - Syringe Leak Testing - Syringe Vacuum Testing - Plunger Manual Unlock - Plunger Automatic Unlock Testing, Partial Aspiration - Plunger Automatic Unlock Testing, Full Aspiration - Vacuum Decay Under Plunger Side-Load - Syringe Tensile and Torque - Particulate Matter - 3 Point Bend Test (Characterization Only) - Push Button Force Testing – Garrote Valve (Characterization Only) - Syringe Plunger Retraction Force (Characterization Only) - Release Tab Force Testing (Characterization Only) - Plunger Side-Load (Characterization Only) # Validation Tests - GLP Animal Safety and Performance Evaluation (including functional testing/radiopacity verification) - Device Tracking to Pulmonary Vasculature - Dilator Engagement During Device Insertion - Dilator Removal from Triever Duo - Compatible Device Insertion Through Triever Duo (FlowTriever XL) - Compatible Device Retraction Through Triever Duo (FlowTriever XL) - Dilator Insertion into Triever Duo - Compatible Device Insertion Through Triever Duo (Triever20 Curve) - Compatible Device Retraction Through Triever Duo (Triever20 Curve) - Syringe Locks During Aspiration - Syringe Manual Unlock - Syringe Vacuum Status - Syringe Automatic Unlock - Clot Burden Removal Efficacy - Device Functionality - Compatible Device Connection at Catheter Hubs - Glove Damage {11} K253419 Page 8 of 8 Test results demonstrated that all acceptance criteria were met; therefore, the device conforms to established product specifications. ### **Clinical Testing** Clinical testing was not required for the determination of substantial equivalence. ### **Conclusion** The Triever Duo Catheter has the same intended use and principles of operation as the predicates. Non-clinical performance data show that the different technological characteristics between the devices do not raise any new or different questions of safety or effectiveness and support the Triever Duo Catheter’s substantial equivalence to the predicate devices.