The Modified Merci® Retriever is intended to restore blood flow in the neurovasculature by removing thrombus in patients experiencing ischemic stroke. Patients who are ineligible for treatment with intravenous tissue plasminogen activator (IV t-PA) or who fail IV t-PA therapy are candidates for treatment. The Modified Merci Retriever is also indicated for use in the retrieval of foreign bodies misplaced during interventional radiological procedures in the neuro, peripheral and coronary vasculature.

Device Description

Like the predicate device, the Modified Merci® Retriever consists of a flexible, Nitinol core wire with shaped loops at the distal end. A radiopaque coil covers the tip allowing visualization under fluoroscopy.

The Retriever is placed distal to the thrombus or foreign body through a microcatheter. The Retriever and microcatheter are pulled back to engage the thrombus or foreign body in the loops of the Retriever. The Retriever, the thrombus or foreign body, and the microcatheter are then removed from the body.

AI/ML Overview

This document is a 510(k) premarket notification for the Modified Merci® Retriever. It focuses on demonstrating substantial equivalence to a predicate device rather than presenting a study to prove acceptance criteria for a new, unique performance claim.

Therefore, many of the requested elements for a study proving acceptance criteria cannot be directly extracted from the provided text because such a study is not detailed. The document's purpose is to show that the Modified Merci® Retriever is like an already approved device, not to establish new performance metrics through a clinical trial.

Here's a breakdown of what can be inferred or directly stated based on the provided text, and what cannot be:

1. A table of acceptance criteria and the reported device performance

The document does not explicitly present a table of acceptance criteria with corresponding performance results. It states:

"All devices met the required specifications for the completed tests." This is a general statement indicating that the device passed internal testing, but the specific "required specifications" (acceptance criteria) and the "completed tests" are not detailed.
The primary "performance" reported is its substantial equivalence to the predicate device, the Merci Retriever, in terms of "indications for use, function, and materials used."

2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)

Test Set Sample Size: Not specified. The document refers to "completed tests" but does not give a sample size for these tests.
Data Provenance: Not specified. Given the nature of a 510(k) for substantial equivalence based on device design and materials, the "tests" likely refer to in-house engineering and biocompatibility testing, not clinical data with human subjects or a specified geographical origin.

3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)

Not applicable. The document does not describe a clinical study where expert ground truth would be established for a test set. This is a technical submission focusing on device design and materials.

4. Adjudication method (e.g. 2+1, 3+1, none) for the test set

Not applicable. No clinical test set requiring adjudication is described.

5. If a multi-reader multi-case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance

Not applicable. This device is a mechanical medical device (thrombus retriever), not an AI diagnostic tool. No MRMC study was conducted or mentioned.

6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done

Not applicable. This is not an algorithm or AI device.

7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)

The concept of "ground truth" as typically used for diagnostic or AI devices is not relevant here. The "truth" for this 510(k) is the established safety and effectiveness of the predicate device, and the claim is that the Modified Merci® Retriever is sufficiently similar to also be safe and effective. Testing likely involved engineering verification (e.g., tensile strength, flexibility, material compatibility) against established specifications for the device's design.

8. The sample size for the training set

Not applicable. This is not an AI/machine learning device, so there is no "training set."

9. How the ground truth for the training set was established

Not applicable for the same reason as above.

Summary of what the document does convey:

Device Type: Modified Merci® Retriever, an endovascular retriever.
Intended Use: Restore blood flow in neurovasculature by removing thrombus in ischemic stroke patients, and retrieve foreign bodies in neuro, peripheral, and coronary vasculature.
Predicate Device: Merci Retriever.
Basis for Acceptance/Clearance: Demonstrating substantial equivalence to the predicate device. This means the FDA found that the new device is as safe and effective as a legally marketed predicate device (the original Merci Retriever) because it has the same intended use, fundamental technological characteristics (flexible Nitinol core wire with shaped loops, radiopaque coil), and similar materials.
Testing: "All devices met the required specifications for the completed tests." (Details of these tests and specifications are not provided in this specific excerpt). These tests would typically include bench testing for performance and material properties.
Regulatory Conclusion: The FDA determined the device is substantially equivalent, allowing it to be marketed.

Summary

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K070521

Y
2

Attachment 5

APR 2 4 2007

510(k) SUMMARY

General Information

Trade Name	Modified Merci® Retriever
Common Name	Endovascular Retriever
Classification	Class II, Catheter, thrombus Retriever per 21 CFR § 870.1250
Submitter	Concentric® Medical, Inc.1380 Shorebird Way

Mountain View, CA 94043 Tel 650-938-2100 Fax 650-938-2700

Contact

Kirsten Valley Senior Vice President, Operations and Regulatory Affairs

Intended Use

The Modified Merci® Retriever is intended to restore blood flow in the neurovasculature by removing thrombus in patients experiencing ischemic stroke. Patients who are ineligible for treatment with intravenous tissue plasminogen activator (IV t-PA) or who fail IV t-PA therapy are candidates for treatment. The Modified Merci® Retriever is also indicated for use in the retrieval of foreign bodies misplaced during interventional radiological procedures in the neuro, peripheral and coronary vasculature.

Predicate Device

Merci Retriever

Device Description

{1}------------------------------------------------

Concentric Medical, Inc. Modified Merci Retriever February 2007

Materials

All materials used in the manufacture of the Retriever are suitable for the intended use of the device and have been used in numerous previously cleared products.

Testing Summary

All devices met the required specifications for the completed tests.

Summary of Substantial Equivalence

The Modified Merci® Retriever is substantially equivalent to the predicate device. The indications for use, function, and materials used are equivalent.

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Image /page/2/Picture/1 description: The image shows the logo for the U.S. Department of Health & Human Services. The logo features a stylized depiction of an eagle or bird-like figure. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" is arranged in a circular fashion around the bird symbol.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Concentric Medical, Inc. % Ms. Kirsten Valley Senior VP, Operations and Regulatory Affairs 1380 Shorebird Way Mountain View, California 94043

APR 2 4 2007

Re: K070521

Trade/Device Name: Modified Merci Retriever Regulation Number: 21 CFR 870.1250 Regulation Name: Percutaneous catheter Regulatory Class: II Product Code: NRY Dated: March 23, 2007 Received: March 26, 2007

Dear Ms. Valley:

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. 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.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to such 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 801); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR 1000-1050.

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Page 2 – Ms. Kirsten Valley

This letter will allow you to begin marketing your device as described in your Section 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801), please contact the Office of Compliance at (240) 276-0115. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). You may obtain other general information on your responsibilities under the Act from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (240) 276-3150 or at its Internet address http://www.fda.gov/cdrh/industry/support/index.html.

Sincerely yours,

for Mark N. Melkerson
Director

Peter Remm
DEP DIR
m2

Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Concentric Medical, Inc. Modified Merci Retriever February 2007

Attachment 3

INDICATIONS FOR USE

Modified Merci Retriever

510(k) Number (if known):

This application

Device Name:

Indications for Use:

Nda. Ramos

(Division Sign-Off) Division of General, Restorative, and Neurological Devices

510(k) Number

Prescription Use X (Per 21 CFR 801.109)

AND/OR

Over-The-Counter Use (Optional Format 1-2-96)

(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Regulation Number and Section

§ 870.1250 Percutaneous catheter.

(a)
Identification. A percutaneous catheter is a device that is introduced into a vein or artery through the skin using a dilator and a sheath (introducer) or guide wire.(b)
Classification. Class II (performance standards).