(31 days)
The Nerve Cuff is intended for the repair of peripheral nerve discontinuities where gap closure can be achieved by flexion of the extremity. The device is supplied sterile and is intended for one-time use.
The Nerve Cuff is composed of a bioabsorbable, extracellular collagen matrix (Small Intestinal Submucosa, SIS). The SIS material that comprises the Nerve Cuff is identical to that of its predicate (Surgisis Nerve Cuff, K031069), and reference device (Nerve Cuff, K132660). Both the predicate and reference devices are also manufactured by Cook Biotech Incorporated. The Nerve Cuff is implanted around an injured nerve to provide a scaffold which becomes infiltrated by the patient's cells and is remodeled into native tissue. In addition, the Nerve Cuff protects the damaged or severed nerve while the nerve heals. The device is packaged in a dried state and supplied sterile in a clamshell container inside a sealed pouch.
This document describes the AxoGuard Nerve Connector (K162741), a Class II medical device intended for the repair of peripheral nerve discontinuities. The submission is a Special 510(k) focusing on a size change for shorter lengths and one narrower diameter of the existing Nerve Cuff.
Here's an analysis of the provided information regarding acceptance criteria and supporting studies:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly state "acceptance criteria" in a single, overarching table with specific numerical targets for the device's main function (nerve repair success). Instead, it presents various tests with their respective acceptance criteria for different aspects of the device's material, handling, and sterility. The reported device performance indicates that these criteria were met.
| Test Category | Specific Test | Acceptance Criteria Summary | Reported Device Performance |
|---|---|---|---|
| Functional Performance | User handling validation | Product possesses acceptable characteristics for handling, trimming, and suturing. | The handling characteristics of the subject device are substantially equivalent to the predicate device based on acceptability to the end-user. All samples met acceptance criteria. |
| Pre-clinical study discussion/evaluation of product line by key opinion leaders | No concerns regarding pre-clinical data and acceptable device handling characteristics. | No concerns regarding pre-clinical data and the handling characteristics of the subject device are substantially equivalent to the predicate device based on acceptability to the end-user. All samples met acceptance criteria. | |
| Bench Testing | Ultimate tensile strength | (Implied: Sufficient strength for intended use and comparable to or superior to predicate, though specific numerical criteria are not given for the subject device - the predicate's performance is the benchmark for comparison.) | The ultimate tensile strength of the material composing the subject device is greater than the predicate device. |
| Suture retention strength | Sufficient to perform the intended use. | The suture retention strength of the material composing the subject device is sufficient to perform the intended use. All samples met acceptance criteria. | |
| Compression and rebound | Ability to rebound to original diameter after compression. | All samples met acceptance criteria with performance comparable to that of the predicate device. | |
| Biocompatibility | Cytotoxicity | Non-cytotoxic. | Pass; Non-cytotoxic. |
| Sensitization | No evidence of sensitization. | Pass; No evidence of sensitization. | |
| Intracutaneous reactivity | No evidence of intracutaneous reactivity. | Pass; No evidence of intracutaneous reactivity. | |
| Acute systemic toxicity | No mortality or evidence of acute systemic toxicity. | Pass; No mortality or evidence of acute systemic toxicity. | |
| Subchronic and chronic toxicity | Non-irritating to subcutaneous tissue; No evidence of subchronic or chronic toxicity. | Pass; Non-irritating to subcutaneous tissue; No evidence of subchronic or chronic toxicity. | |
| Genotoxicity | Device extracts are non-mutagenic. | Pass; Device extracts are non-mutagenic. | |
| Implantation | Irritation not greater than control materials at 24 weeks. | Pass; Irritation not greater than control materials at 24 weeks. | |
| Sterilization | Sterilization validation | Devices have a sterility assurance level (SAL) of 10-6. | Pass; Devices have a sterility assurance level (SAL) of 10-6. |
2. Sample Sizes Used for the Test Set and Data Provenance
The document does not explicitly state distinct "test sets" with specific sample sizes for this submission (K162741) in the context of evaluating algorithm performance or clinical outcomes. Instead, it leverages data from the predicate device (K031069) and reference device (K132660) due to identical material and manufacturing processes.
- User handling validation: "representative final product" was used. Specific sample size not given.
- Pre-clinical study discussion/evaluation: "representative final product" was used. Specific sample size not given.
- Bench Testing:
- Ultimate tensile strength: Not specified.
- Suture retention strength: "All samples met acceptance criteria." Specific sample size not given.
- Compression and rebound: "All samples met acceptance criteria." Specific sample size not given.
- Biocompatibility Testing:
- Cytotoxicity: Not specified.
- Sensitization: Guinea pigs (sample size not given).
- Intracutaneous reactivity: Rabbits (sample size not given).
- Acute systemic toxicity: Mice (sample size not given).
- Subchronic and chronic toxicity: Rats for 4 weeks (subchronic) and 18 weeks (chronic) (sample size not given).
- Genotoxicity: Not specified.
- Implantation: Rabbits for 4, 12, and 24 weeks (sample size not given).
- Sterilization validation: Not specified.
Data Provenance: The studies cited (bench, biocompatibility, sterilization) relate to the material and manufacturing process, which are stated to be identical to the predicate device (Surgisis Nerve Cuff, K031069). Therefore, the data provenance is indirectly tied to the studies performed for that predicate, which would have been conducted to support its clearance. There is no information regarding country of origin or whether these original studies were retrospective or prospective in this document.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
- Key Opinion Leaders / Surgeons: For the "User handling validation" and "Pre-clinical study discussion/evaluation," surgeons and "key opinion leaders" were involved. The exact number of experts and their specific qualifications (e.g., years of experience or specialty beyond "surgeon") are not detailed. Their role was to assess handling characteristics and provide feedback on pre-clinical data.
- For other tests (bench, biocompatibility, sterilization), the "ground truth" is established by adherence to recognized standards (e.g., ISO, EN ISO) and objective measurements, not by expert consensus in the same way clinical ground truth is established.
4. Adjudication Method for the Test Set
The document does not describe an adjudication method for a "test set" in the context of clinical outcomes or diagnostic accuracy. For the "User handling validation" and "Pre-clinical study discussion/evaluation," it states "acceptability to the end user" and "No concerns regarding pre-clinical data," implying a consensus or agreement among the participating experts/surgeons, but no specific adjudication method (e.g., 2+1, 3+1) is mentioned.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This document is for a medical device (nerve cuff), not an AI or imaging diagnostic algorithm. Therefore, the concept of human readers improving with or without AI assistance is not applicable. The device's performance is assessed through material properties, biocompatibility, and handling, mainly by comparison to a predicate device.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
No, a standalone performance study in the context of an algorithm has not been done. This is a hardware medical device, not a software algorithm.
7. The Type of Ground Truth Used
The "ground truth" used for various tests is primarily objective measurements and established scientific/biological standards:
- Functional Performance (User handling, Pre-clinical discussion): Subjective assessment by surgeons/key opinion leaders (qualitative "ground truth" on handling and acceptability).
- Bench Testing (Tensile strength, Suture retention, Compression/rebound): Direct physical measurements and comparison to performance of the predicate device, against engineering specifications and the device's intended function.
- Biocompatibility Testing: Biological responses observed in animal models (mice, guinea pigs, rabbits) and in vitro tests, evaluated against established safety profiles and ISO standards. This is akin to pathology/biological response data.
- Sterilization Validation: Microbiological testing to achieve a specific Sterility Assurance Level (SAL), based on established sterilization protocols (EN ISO 11135).
There is no mention of pathology, clinical outcomes data from human trials, or expert consensus on disease diagnosis as ground truth, as the submission focuses on safety and performance characteristics for a device that provides a physical structure for nerve repair, rather than a diagnostic tool.
8. The Sample Size for the Training Set
The concept of a "training set" is not applicable here as this is not an AI/machine learning device. The device's characteristics are established through various physical, chemical, and biological tests, not through training on a dataset.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no "training set" for this type of medical device submission.
§ 882.5275 Nerve cuff.
(a)
Identification. A nerve cuff is a tubular silicone rubber sheath used to encase a nerve for aid in repairing the nerve (e.g., to prevent ingrowth of scar tissue) and for capping the end of the nerve to prevent the formation of neuroma (tumors).(b)
Classification. Class II (performance standards).