(90 days)
VersaWrap Nerve Protector is indicated for the management of peripheral nerve injuries in which there has been no substantial loss of nerve tissue.
VersaWrap Nerve Protector (VersaWrap) is designed to function as an interface between an injured nerve and surrounding tissues and is indicated for use in peripheral nerve injuries where there is no significant loss of nerve tissue. VersaWrap Nerve Protector is a thin, flexible implant, designed to be a non-constricting gelatinous interface encasing peripheral nerves and the neural environment; that starts to absorb after implant. VersaWrap Nerve Protector is designed to be flexible and conformable for placement around a peripheral nerve
The provided text describes non-clinical tests and an animal study for the VersaWrap Nerve Protector. Here's a breakdown of the requested information based on the provided input:
1. A table of acceptance criteria and the reported device performance
| Acceptance Criteria Category | Specific Test/Purpose | Acceptance Criteria Summary | Reported Device Performance |
|---|---|---|---|
| Non-Clinical Tests | Dimensional & Visual Inspection | Direct measurement of mass, lengths, width, thickness with micrometers, calipers, pH meter or balance; and visual inspection. | Dimensional analysis was completed to verify the dimensions and visual characteristics and met specifications. |
| Pliability/Tissue Conformance and Adherence | The device is placed on a simulated model and graded for visual conformance and adherence. | Visual inspection was conducted and met specifications. | |
| Swelling | Direct measurement of the device (with micrometers, calipers) when exposed to fluid. | Dimensional analysis was completed and met specifications. | |
| Strength/Puncture | Direct measurement of the device strength/puncture when measured with a probe. | Testing was completed and met specifications. | |
| Pouch Seal Integrity/Sterile Barrier | The integrity of the pouch was verified with a visual inspection, peel tester, and burst tester. | Testing was completed and met specifications. | |
| Sterilization | The e-beam sterilization process was validated to achieve a sterility assurance level (SAL) of 10-6 per ISO 11137. | Testing was completed and met specifications. | |
| Bacterial Endotoxin Validation | The bacterial endotoxin validation testing was conducted per USP Bacterial Endotoxins and Ph.Eur. Chpt 2.6.14. | Testing was completed and met specification. | |
| Cytotoxicity | The device was evaluated for potential cytotoxic effects using an in vitro mammalian cell culture test, following ISO 10993-5 guidelines. | The test extract showed no evidence of causing cell lysis or toxicity. | |
| Sensitization | The device was evaluated for the potential to cause delayed dermal contact sensitization in a guinea pig maximization test, based on ISO 10993-10. | The test article showed no evidence of causing delayed contact sensitization. | |
| Irritation | The device was evaluated for the potential to cause irritation following intracutaneous injection, based on ISO 10993-10. | There was no evidence of significant irritation from the extracts injected intracutaneously. | |
| Acute Systemic Toxicity | The device was evaluated for acute systemic toxicity, based on ISO 10993-11. | The sesame oil test article extracts and the sodium chloride test article extracts injected met the passing requirements of the test. | |
| Pyrogenicity | The device was evaluated for material mediated pyrogenicity in the rabbit. | The total rise of temperatures during the observation period was within acceptable limits (implied by "Testing was completed and met specifications" below). | |
| Genotoxicity | The device was evaluated for mutagenic potential, mutagenic changes, and to produce cytogenetic damage. | Extract did not cause cytogenetic damage/micronuclei formation. Extracts were well within the limits defined for a negative response and the test article is considered non-mutagenic. | |
| Subchronic Toxicity | The device was surgically implanted in the subcutaneous tissue of the rat to evaluate potential systemic toxicity and local tissue response at the implantation sites. | No evidence of systemic toxicity following subcutaneous implantation. Microscopically, the test article was classified as a non-irritant. | |
| Muscle Implantation | The study assessed local tissue effects and absorption profile following implantation in muscle tissue in at multiple timepoints. | At long term timepoints the device was considered to be a non-irritant and a slight irritant at earlier weeks following implantation when compared to the control. Microscopic evaluation demonstrated the device is bioresorbing as expected. | |
| Neurotoxicity Assessment | A risk analysis was conducted to determine any neurotoxicity risk to the patient. | An analysis was conducted to determine any neurotoxicity risk to the patient (implied satisfactory outcome given overall conclusion). | |
| Animal Study | Performance/Safety | Comparable safety and performance to predicate device, no significant events, no apparent difference in character or severity of reactivity to test or predicate implant, no microscopic changes in the nerve at any interval for either test or Integra implants, similar microscopic appearance of nerve and surrounding tissue for control and VersaWrap. | VersaWrap animals and the predicate control animals demonstrated equivalent safety and equivalent performance results; there were no significant events reported in any group. Histopathological evaluations showed no apparent difference in the character or severity of the reactivity, and no microscopic changes in the nerve. |
2. Sample size used for the test set and the data provenance
- Test Set Sample Size: The document states the "sample size was selected to be large enough to show consistent results and to be able to compare the test, control, and untreated groups" for the animal study. However, a specific numerical sample size is not explicitly provided for the animal study (e.g., "N=X rats"). For non-clinical tests, sample sizes are implied by "testing was completed" but not detailed (e.g., number of pouches for seal integrity, number of samples for cytotoxic evaluation).
- Data Provenance:
- Country of Origin: Not specified.
- Retrospective or Prospective: The animal study appears to be prospective as it involved conducting the study on "multiple injury types for subject device, predicate control device, and untreated groups" with data collected at "an early period, a mid-term period; and a late period." The non-clinical tests are also inherently prospective as they are performed on the device.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- The document does not provide information on the number of experts or their qualifications used to establish ground truth for the animal study or any other test. It mentions "Histopathological evaluations were performed," which implies expert analysis, but details are lacking.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- The document does not specify any adjudication method for the test set, whether for the animal study or non-clinical tests.
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 comparative effectiveness study was not done. This device is a physical nerve protector and not an AI-assisted diagnostic tool. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- No, a standalone algorithm-only performance study was not done. This device is a physical medical implant, not an algorithm or software.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- For the animal study, the ground truth appears to be based on pathology/histopathology ("Histopathological evaluations were performed to assess local and systemic tissue effects...There were no microscopic changes in the nerve...") and physiological/observational outcomes data ("motor and sensory neurological assessments were conducted...no significant events reported").
- For non-clinical tests, the "ground truth" is typically defined by pre-defined specifications and validated test methods (e.g., ISO standards for biocompatibility, direct measurements for dimensional analysis).
8. The sample size for the training set
- This device is not an AI/ML model, so there is no concept of a "training set" as described in the context of AI.
9. How the ground truth for the training set was established
- As there is no training set for an AI/ML model, this question is not applicable.
§ 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).