K213402 · Inari Medical · QEW · May 23, 2022 · Cardiovascular
Device Facts
Record ID
K213402
Device Name
Triever24, Triever20
Applicant
Inari Medical
Product Code
QEW · Cardiovascular
Decision Date
May 23, 2022
Decision
SESE
Submission Type
Special
Regulation
21 CFR 870.5150
Device Class
Class 2
Attributes
Therapeutic
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. Triever Catheters are also intended for use in transit in the right atrium but not in conjunction with FlowTriever Catheters.
Device Story
FlowTriever Retrieval/Aspiration System is a single-use, over-the-wire, catheter-based system for minimally invasive mechanical thrombectomy. System components include Triever Catheters (16, 20, 24 Fr) and FlowTriever Catheters (6-25 mm). Procedure: Triever catheter advanced to thrombus over 0.035" guidewire; FlowTriever catheter inserted through Triever catheter; self-expanding wireform disks deployed to engage thrombus; FlowTriever retracted into Triever to capture clot; aspiration performed via 60 cc VacLok syringe. Used in clinical settings by physicians. Output is physical removal of thrombus/emboli. Benefits include minimally invasive clot removal, reducing need for surgery. Modifications improve deliverability, kink resistance, hemostasis valve durability, and vacuum reliability.
Clinical Evidence
No clinical data. Substantial equivalence supported by bench testing, including visual/dimensional inspection, 3-point bend, retraction force, clot burden removal validation, vacuum/leak testing, kink radius, and biocompatibility (ISO 10993-1).
Technological Characteristics
Catheter-based embolectomy system; over-the-wire (0.035" guidewire). Components: Triever catheters (16, 20, 24 Fr) and FlowTriever catheters (6-25 mm). Materials: biocompatible polymers/metals per ISO 10993-1. Mechanical aspiration via 60 cc VacLok syringe. Single-use, sterile. No software or electronic components.
Indications for Use
Indicated for non-surgical removal of emboli and thrombi from peripheral vasculature and treatment of pulmonary embolism; also for clot in transit in right atrium. Used for injection, infusion, or aspiration of fluids/contrast media.
Regulatory Classification
Identification
An embolectomy catheter is a balloon-tipped catheter that is used to remove thromboemboli, i.e., blood clots which have migrated in blood vessels from one site in the vascular tree to another.
Predicate Devices
Inari FlowTriever Retrieval/Aspiration System (K211013)
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May 23, 2022
Inari Medical Kit Cariquitan VP, RA/QA 9 Parker. Suite 100 Irvine, California 92618
Re: K213402
Trade/Device Name: Triever24, Triever20 Regulation Number: 21 CFR 870.5150 Regulation Name: Embolectomy Catheter Regulatory Class: Class II Product Code: QEW, KRA Dated: April 27, 2022 Received: April 28, 2022
### Dear Kit Cariquitan:
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 (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 located 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 Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
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
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801); medical device reporting of medical device-related adverse events) (21 CFR 803) for devices or postmarketing safety reporting (21 CFR 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reportingcombination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR 4. Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR Part 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-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (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-device-advice-comprehensive-regulatoryassistance/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,
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
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## Indications for Use
510(k) Number (if known) K213402
Device Name Triever24, Triever20
| Indications for Use (Describe) | 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.
Triever Catheters are also intended for use in transit in the right atrium but not in conjunction with FlowTriever Catheters.
| Type of Use (Select one or both, as applicable) | |
|-------------------------------------------------|--|
|-------------------------------------------------|--|
X Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
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# 510(K) SUMMARY
| Date prepared | October 15, 2021 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Name | Inari Medical, Inc.<br>6001 Oak Canyon, Suite 100<br>Irvine, CA 92618<br>949.600.8433 |
| Contact person | Ellen Nguyen<br>Regulatory Affairs Specialist |
| Name of Device | Triever24, Triever20 |
| Common name | Embolectomy catheter |
| Regulation name | Embolectomy catheter |
| Classification number | 21 CFR 870.5150 |
| Primary product code | QEW |
| Secondary product code | KRA |
| Regulatory class | II |
| Predicate device | Inari FlowTriever Retrieval/Aspiration System (K211013)<br>The Triever20 (K182233) was subject to a design-related recall (Z-2299-2020),<br>initiated by Inari on March 23, 2020 and terminated by FDA on August 13, 2021. |
| Description | The FlowTriever Retrieval/Aspiration System is a single-use over-the-wire catheter-based system for the minimally invasive treatment of thromboemboli in the peripheral vasculature and for the treatment of pulmonary embolism. The system is comprised of two main components packaged separately:<br>• Triever Catheters (available in 3 sizes: 16, 20, and 24 Fr)<br>• FlowTriever Catheters (available in 4 sizes: 6-10 mm, 11-14 mm, 15-18 mm, and 19-25 mm)<br>The FlowTriever Catheter is inserted through the Triever Catheter and advanced to the thrombus. Self-expanding wireform disks are deployed to engage thrombus by retracting the outer delivery catheter. The FlowTriever Catheter is retracted into the Triever Catheter to capture the targeted thrombus. Additional clot may be removed by aspiration with the provided 60 cc VacLok Vacuum syringe. After the procedure is complete, the Triever Catheter and FlowTriever Catheter are removed from the patient. |
| Indications for Use | The FlowTriever Retrieval/Aspiration System is indicated for:<br>• The non-surgical removal of emboli and thrombi from blood vessels.<br>• Injection, infusion, and/or aspiration of contrast media and other fluids into or from a blood vessel.<br>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<br>atrium but not in conjunction with FlowTriever Catheters. |
| Device Modifications | The proposed modifications to the Triever24 and Triever20 devices include minor<br>changes to the catheter shafts; material, design, and dimensional changes to the<br>dilators; and material and dimensional changes to the hemostasis valves and<br>sideports. |
| | The purpose of this submission is to introduce modifications to the Triever24 and<br>Triever20 catheters which result in improved catheter deliverability and kink<br>resistance, hemostasis valve durability and vacuum reliability, dilator support,<br>and overall ease of use for the operator. |
| | There have been no changes to the FlowTriever Catheters. |
| Comparison of<br>Technological<br>Characteristics with the<br>Predicate Device | The proposed devices and predicate device have a similar design and materials of<br>construction. The modifications to the cleared Triever24 catheter proposed in this<br>submission include a length increase and the addition of a lubricious additive to<br>the distal shaft, a corresponding length decrease of the proximal shaft, a<br>durometer change to the transition segment, and a stopcock lumen increase. |
| | The modifications to the cleared Triever20 catheter proposed in this submission<br>include the addition of a transition segment, a corresponding length decrease and<br>durometer change to the proximal shaft, and a sideport tube wall thickness<br>increase. |
| | The modifications applicable to both Triever24 and Triever20 catheters devices<br>proposed in this submission include catheter coil changes, hemostasis valve<br>inner mechanism material changes, dilator material and design changes, and the<br>removal of the Y-Connector Valve from the packaging, |
| | The modifications do not change the basic design, the indications for use, or the<br>principles of operation from the predicate device. All Triever Catheters are<br>tracked over the pre-placed 0.035" guidewires. The Triever16, 20, and 24 can<br>each be used as a standalone device. The Triever16 can also be used coaxially<br>through a Triever20 or Triever24. |
| | FlowTriever Catheters can be used for mechanical thrombectomy by deploying<br>directly through the Triever16, Triever20, or Triever24. |
| | The way the modified Triever24 and Triever20 devices are used alone or in<br>conjunction with the Triever16 or with the FlowTriever Catheters remains<br>unchanged from the predicate. Therefore, there are no technological differences<br>between the devices. |
| | There have been no changes to the FlowTriever Catheters. |
| Summary of substantial<br>equivalence | There is no change of intended use or fundamental scientific technology between<br>the proposed devices and predicate device. The Triever24 and Triever20 have the<br>same indication for use as the predicate device, K211013. |
| | Biocompatibility |
| The following biocompatibility tests were conducted for the subject devices: | |
| • Cytotoxicity | • Sensitization |
| • Intracutaneous Reactivity | • Acute Systemic Toxicity |
| • Material-Mediated Pyrogenicity | |
| • Hemocompatibility (Hemolysis, Complement Activation, Thromboresistance, Platelet and Leukocyte Count, and Partial Thromboplastin Time) | |
| The passing results demonstrate that the subject devices and accessories meet biological safety requirements per ISO 10993-1. | |
| Non-Clinical Testing | |
| In accordance with the Design Failure Modes and Effects Analysis, verification and validation testing were identified to support the substantial equivalence of the modified Triever24 and Triever20 devices. This testing demonstrated compliance with relevant product specifications. These tests, performed for both devices unless otherwise noted, include: | |
| • Visual & Dimensional Inspection – Catheter | |
| • Visual & Dimensional Inspection – Dilator | |
| • Guidewire and Dilator Compatibility Verification | |
| • 3-Point Bend Test | |
| • Removal and Insertion Force of Dilator | |
| • Retraction Force of Self-Expanding Elements into Catheter | |
| • Clot Burden Removal Validation | |
| • Air Leakage during Aspiration | |
| • Leak Test | |
| • Vacuum Test | |
| • Kink Radius Test | |
| • Flow Rate through Catheter (Triever24 only) | |
| • Stopcock Misuse Leakage Test (Triever24 only) | |
| • Simulated Use and Tensile Test - Catheter and Dilator | |
| • Simulated Use and Tensile Test – Stopcock (Triever24 only) | |
| • Simulated Use and Tensile Test – Swivel Hub and Sideport (Triever20 only) | |
| • Torque Test - Stopcock (Triever24 only) and Catheter | |
| • Locking/Unlocking Force and Torque between Dilator and Catheter Hub | |
| • Particulate Matter | |
| The following testing was leveraged from previously cleared Inari devices for both devices unless otherwise noted: | |
| • Pouch Seal Visual Inspection and Dye Penetration |…
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.