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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 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.

Like the predicate devices, 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.

The provided documents describe a 510(k) submission for a modified Merci Retriever, a device used to remove thrombus in ischemic stroke patients and retrieve foreign bodies. However, this submission focuses on demonstrating substantial equivalence to predicate devices rather than a study proving the device meets specific acceptance criteria based on performance metrics.

Here's a breakdown based on the information provided and what is missing:

1. Table of Acceptance Criteria and Reported Device Performance

• Indications for Use
• Function
• Materials used | "The modified Merci Retriever is equivalent to the predicate devices. The indications for use, function, and materials used are substantially equivalent." | This is the primary "acceptance criterion" for a 510(k) submission, not performance metrics. No specific quantitative performance criteria (e.g., success rates, complication rates) are provided. |
  | Material Suitability | "All materials used... are suitable for the intended use." | "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." | This is a qualitative statement, not a specific, measurable criterion with associated performance data. |
  | Required Specifications (General) | Met required specifications for completed tests. | "All devices met the required specifications for the completed tests." | This is a general statement. The specific tests and their required specifications are not detailed in the provided text. It likely refers to bench testing (e.g., mechanical, biocompatibility) rather than clinical performance. |

Missing Information:

• Specific, quantitative performance-based acceptance criteria (e.g., a target success rate for thrombus retrieval, a maximum allowable device-related complication rate, specific mechanical test thresholds).
• Detailed results of the "completed tests" that led to the statement "All devices met the required specifications."

2. Sample Size Used for the Test Set and Data Provenance

This information is not provided in the given text.

• Sample Size: No information on the number of patients or cases used for any clinical testing. The submission focuses on substantial equivalence based on device characteristics rather than new clinical data from a dedicated test set.
• Data Provenance: Not mentioned.

3. Number of Experts Used to Establish Ground Truth and Qualifications

This information is not provided. As no clinical or imaging study data is presented, there's no mention of ground truth establishment by experts.

4. Adjudication Method

This information is not provided.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

This information is not provided. The submission does not describe a clinical study comparing human readers with and without AI assistance. This device is a physical medical device (retriever), not an AI diagnostic tool.

6. Standalone (Algorithm Only) Performance Study

This information is not applicable/not provided. The Merci Retriever is a physical medical device, not an algorithm, so a standalone algorithm performance study is not relevant.

7. Type of Ground Truth Used

This information is not provided. If bench testing was performed, the "ground truth" would be the engineering specifications. For clinical performance, it would typically be clinical outcomes or expert adjudication, but no such data is presented.

8. Sample Size for the Training Set

This information is not applicable/not provided. This is a physical device, not a machine learning algorithm, so there is no "training set."

9. How the Ground Truth for the Training Set was Established

This information is not applicable/not provided.

Summary of the Study Discussed (510(k) Submission):

The provided documents describe a 510(k) Premarket Notification for a modification to the Merci® Retriever. The "study" described is essentially the documentation and rationale presented to the FDA to demonstrate substantial equivalence to previously cleared predicate devices (Merci® Retriever K033736 and Modified Merci® Retriever K061059).

• Purpose of the "Study": To demonstrate that the modified Merci® Retriever is as safe and effective as existing legally marketed predicate devices, mainly by showing that its indications for use, function, and materials are substantially equivalent.
• Key Findings: The submission states that the modified device is substantially equivalent, and that "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" and "All devices met the required specifications for the completed tests."
• Nature of the Evidence: The evidence primarily comprises:
  • Comparison of design features and materials to predicate devices.
  • Statements regarding the suitability of materials.
  • A general statement that "all devices met the required specifications for the completed tests" (likely referring to bench testing, but details are not provided).
• Clinical Data: No new clinical trial data, human subject testing, or expert reviews of clinical outcomes are detailed in the provided text for this specific 510(k) modification. This type of submission often relies on a comparison to predicate devices, and sometimes existing clinical data for the predicate device, rather than new, extensive clinical studies for minor modifications.

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