(29 days)
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.
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.
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.
§ 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).