The 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 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 design of the modified Merci Retriever consists of a flexible, tapered Nitinol core wire. This distal end is shaped into a helix and a platinum coil is threaded over and attached to the distal end. Polymer filaments are attached to the distal end. The core wire proximal to the helix is coated with a hydrophilic coating. A torque device is provided with Retriever to facilitate manipulation. An insertion tool is provided with Retriever to introduce Retriever into Microcatheter during the procedure.

AI/ML Overview

The provided text describes a 510(k) submission for a modified Merci Retriever, a medical device used for removing thrombus in ischemic stroke patients and retrieving foreign bodies. However, this document primarily focuses on demonstrating substantial equivalence to a predicate device rather than presenting a performance study with detailed acceptance criteria and supporting data as one would expect for a novel device or a clinical trial.

Therefore, many of the requested sections (acceptance criteria, specific study details, ground truth, expert involvement, MRMC study, sample sizes for training/test sets) cannot be extracted from the provided text because the document does not contain this type of performance study. The core of this submission is a "Testing Summary" stating that "Results of design verification and validation testing performed on the modified Merci Retriever confirm that the device conforms to the required specifications and establish substantial equivalence to the predicate device." This suggests that the evaluation was likely focused on engineering specifications and direct comparison to a previously cleared device, not a clinical performance study with defined acceptance criteria for metrics like sensitivity, specificity, etc.

Here's a breakdown of what can and cannot be provided based on the input:

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

Acceptance Criteria	Reported Device Performance
Not Available	Not Available

Explanation: The document does not specify quantitative acceptance criteria for device performance (e.g., successful clot retrieval rates, recanalization rates) or present data from a clinical study to demonstrate such performance. The submission aims to establish substantial equivalence based on design verification and validation testing, not a clinical outcome study against predetermined performance metrics.

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

Sample Size for Test Set: Not applicable / Not available. The document refers to "design verification and validation testing," which typically involves bench testing, material testing, and potentially animal studies, rather than human clinical trials with a "test set" in the context of AI or diagnostic device performance evaluation.
Data Provenance: Not applicable / Not available. No clinical data or human subject data is described.

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 / Not available. The concept of "ground truth" established by experts for a test set is relevant to studies evaluating diagnostic accuracy or AI performance. This document does not describe such a study.

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

Not applicable / Not available. Adjudication methods are used to establish ground truth in studies involving human interpretation or clinical endpoints. This information is not present.

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

No. An MRMC study was not done. This device is an endovascular retriever, not an AI-assisted diagnostic tool.

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

Not applicable / No. This device is a physical medical instrument, not a software algorithm.

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

Not applicable / Not available. The document describes a physical medical device and its substantial equivalence to a predicate device, focusing on engineering and material specifications rather than clinical outcomes with a defined "ground truth."

8. The sample size for the training set

Not applicable / Not available. There is no mention of a "training set" as this is not an AI/machine learning device.

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

Not applicable / Not available. There is no mention of a "training set" or "ground truth" in the context of device performance in the provided document.

Summary of what the document does state regarding acceptance/testing:

The submission focuses on "substantial equivalence" to a predicate device (Merci® Retriever, K081305). The "Testing Summary" on page 1 states:

"Results of design verification and validation testing performed on the modified Merci Retriever confirm that the device conforms to the required specifications and establish substantial equivalence to the predicate device."

And then explicitly lists:

"The modified Merci Retriever is substantially equivalent to the predicate device with regard to intended use, operating principal, design concept, materials, shelf life, packaging and sterilization processes."

This indicates that the "acceptance criteria" were met by demonstrating that the modified device's specifications (design, materials, functionality) were sufficiently similar to the predicate device, or met internal engineering requirements, to justify an equivalence claim rather than requiring new clinical performance data against specific endpoints.

Summary

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AUG 1 5 2008

510(k) SUMMARY OF SAFETY AND EFFECTIVENESS

General Information

Trade Name	Merci® Retriever
Common Name	Endovascular Retriever
Classification	Thrombus Retriever, 21CFR 870.1250 – Class II
Submitter	Concentric® Medical, Inc.301 E. Evelyn AvenueMountain View, CA 94041Tel 650-938-2100Fax 650-938-2700
Contact	Laraine PangelinaDirector, Regulatory Affairs

Intended Use

The intended use for the modified Merci Retriever is the same as the intended use of the predicate Merci Retriever:

Predicate Device

Merci® Retriever, K081305

Device Description

Materials

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

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Testing Summary

Results of design verification and validation testing performed on the modified Merci Retriever confirm that the device conforms to the required specifications and establish substantial equivalence to the predicate device.

Summary of Substantial Equivalence

The modified Merci Retriever is substantially equivalent to the predicate device with regard to intended use, operating principal, design concept, materials, shelf life, packaging and sterilization processes.

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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 consists of a circular seal with the text "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA" around the perimeter. Inside the circle is an abstract symbol that resembles a stylized caduceus or a representation of human services.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

Concentric Medical, Inc. % Ms. Laraine Pangelina Director, Regulatory Affairs 301 East Evelyne Avenue Mountain View, California 94041

AUG 1 5 2008

Re: K082034

Trade/Device Name: Merci Retriever Regulation Number: 21 CFR 870.1250 Regulation Name: Percutaneous catheter Regula ory Class: II Product Code: NRY Dated: July 16, 2008 Received: July 17, 2008

Dear Ms. Pangelina:

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 subj .ct 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. Laraine Pangelina

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 Center for Devices and Radiological Health's (CDRH's) Office of Compliance at (240) 276-0115. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21CFR Part 807.97). For questions regarding postmarket surveillance, please contact CDRH's Office of Surveillance and Biometric's (OSB's) Division of Postmarket Surveillance at (240) 276-3474. For questions regarding the reporting of device adverse events (Medical Device Reporting (MDR)), please contact the Division of Surveillance Systems at (240) 276-3464. 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.

Mark N. Walken

Mark N. Melkerson Director Division of General, Restorative and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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INDICATIONS FOR USE

510(k) Number (if known):	This application
Device Name:	Merci Retriever
Indications for Use:	The Merci® Retriever is intended to restore blood flow in theneurovasculature by removing thrombus in patientsexperiencing ischemic stroke. Patients who are ineligible fortreatment with intravenous tissue plasminogen activator (IV t-PA) or who fail IV t-PA therapy are candidates for treatment.The Merci Retriever is also indicated for use in the retrieval offoreign bodies misplaced during interventional radiologicalprocedures in the neuro, peripheral and coronary vasculature.

510(k) Number (if known):

This application

Device Name:

Merci Retriever

Indications for Use:

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

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)

Mark A. Millhiser

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

510(k) Number K082034

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).