(90 days)
IMPRA Carboflo™ ePTFE Vascular Grafts are intended for use in peripheral vascular applications to replace or bypass diseased or occluded blood vessels.
IMPRA Carboflo™ ePTFE Vascular Grafts are made primarily of expanded polytetrafluoroethylene (ePTFE) using the same manufacturing procedures that are used to manufacture IMPRA ePTFE Vascular Grafts, the devices to which substantial equivalence is claimed, The region of the graft wall adjacent to the lumen, approximately 20-25% of the total wall thickness, is uniformly impregnated with Carbon particles along the entire length of the graft. The carbon impregnated region is formed integral to the outer region of the wall by mixing the PTFE resin mixed with carbon particles, with the non-carbon containing PTFE resin during a singular extrusion process, which results in a monolithic graft wall. The carbon used in the device is USP grade activated charcoal. All other components of the Carboflo graft, namely PTFE, lubricant used as a manufacturing aid, blue pigment incorporated in the orientation lines, and the external support PTFE beading are the same as those used in the manufacture of the predicate devices. These grafts are supplied in the same product configurations as the predicate device, and are packaged, labeled, and sterilized in the same manner as the predicate devices.
Here's a breakdown of the acceptance criteria and the study that proves the device meets them, based on the provided text:
Acceptance Criteria and Device Performance
The core of the acceptance criteria is the demonstration of substantial equivalence to the predicate device, the IMPRA ePTFE Vascular Graft. This is primarily assessed through physical properties and clinical performance (patency rates and adverse events).
| Acceptance Criteria Category | Specific Criteria | Reported Device Performance (IMPRA Carboflo™ ePTFE Vascular Graft) |
|---|---|---|
| Substantial Equivalence (Physical Properties) | Physical properties of Carboflo vascular grafts did not affect by addition of carbon particles to graft wall. | "Testing of a variety of product types shows that the addition of carbon particles into the graft wall did not affect the physical properties of the Carboflo grafts. Both the new device and predicate device undergo the same testing and evaluation procedures. The acceptance criteria for both the new device and predicate devices are the same." |
| Patencty Rates | Similar patency rates to the predicate device (IMPRA ePTFE Vascular Graft). | 24-month Cumulative Primary Patency: 36.8% (Carboflo) vs. 27.7% (Standard). |
| 24-month Cumulative Secondary Patency: 42.7% (Carboflo) vs. 32.3% (Standard). | ||
| (Note: "These results are not statistically significantly different at p=0.05.") | ||
| Device Safety (Adverse Events) | No new types of complications identified compared to the predicate device. Acceptable rates of known complications. | No new types of complications were identified. |
| Thrombosis: 26 (Carboflo) vs. 34 (Standard) | ||
| False Aneurysm: 1 (Carboflo) vs. 1 (Standard) | ||
| Infection: 4 (Carboflo) vs. 5 (Standard) | ||
| Other Adverse Events: 3 (Carboflo) vs. 2 (Standard) | ||
| Amputation: 28 (Carboflo) vs. 26 (Standard) | ||
| Deaths: 13 (Carboflo) vs. 16 (Standard) |
Study Details
The provided document describes a clinical study and also refers to non-clinical (animal) studies and bench testing. Here's a breakdown of the relevant information:
1. Sample Size Used for the Test Set and Data Provenance:
-
Clinical Test Set:
- Total Patients: 160
- Carboflo Group: 81 patients
- Standard ePTFE Group: 79 patients
- Data Provenance: Prospective, multi-center, randomized clinical trial conducted in France between 1990-1994.
-
Non-Clinical (Animal) Test Set:
- Short-term pre-clinical studies: Dogs and rabbits (specific numbers not provided).
- Longer-term pre-clinical studies: Specific animal models not explicitly stated beyond "animal studies" (specific numbers not provided).
2. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- This information is not explicitly provided for the clinical trial. Clinical trials usually involve investigators and potentially a Data Monitoring Committee, but their specific roles in establishing "ground truth" for each outcome are not detailed in this summary.
- For the non-clinical studies ("Thrombus Free Surface Area" after 3 months, "reduced platelet accumulation"), the judgment would be made by veterinary pathologists or researchers. Specific numbers and qualifications are not mentioned.
3. Adjudication Method for the Test Set:
- Not explicitly described. Clinical trials typically have methods for adjudication of adverse events and endpoints, but the specific process (e.g., 2+1, 3+1 consensus) is not detailed in this summary. Adverse events were "recorded and documented on Case Report Forms (CRF)".
4. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study was done:
- No, this was not an MRMC study. This was a randomized controlled trial comparing two different medical devices in human patients, not a study evaluating human reader performance with or without AI assistance on various cases.
5. If a Standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- Not applicable. This device is a vascular graft, not an AI algorithm. Therefore, the concept of "standalone performance" for an algorithm doesn't apply here. The document describes the performance of the physical device itself.
6. The Type of Ground Truth Used:
- Clinical Trial: The ground truth for patency was determined by the progression or failure of the graft over time, assessed through clinical follow-up and interventions. Adverse events were identified and recorded based on direct patient observation and medical documentation.
- Non-Clinical (Animal) Studies:
- "Thrombus Free Surface Area" (measured after 3 months).
- "Platelet accumulation" (measured in dogs and rabbits).
- Bench Testing: Physical properties of the grafts.
7. Sample Size for the Training Set:
- Training Set for the Device: Not applicable in the context of an AI device. For a manufactured medical device like a vascular graft, "training set" would refer to manufacturing process development and quality control. The document mentions "Extensive bench testing and microscopic analysis" during manufacturing, but does not provide specific sample sizes that would be analogous to an AI training set.
8. How the Ground Truth for the Training Set was Established:
- Not applicable as this is not an AI device. For device manufacturing, ground truth for quality control and material properties (e.g., tensile strength, porosity) would be established through standardized physical and chemical testing methods, often guided by industry standards (e.g., AAMI Vascular Graft Standard).
§ 870.3450 Vascular graft prosthesis.
(a)
Identification. A vascular graft prosthesis is an implanted device intended to repair, replace, or bypass sections of native or artificial vessels, excluding coronary or cerebral vasculature, and to provide vascular access. It is commonly constructed of materials such as polyethylene terephthalate and polytetrafluoroethylene, and it may be coated with a biological coating, such as albumin or collagen, or a synthetic coating, such as silicone. The graft structure itself is not made of materials of animal origin, including human umbilical cords.(b)
Classification. Class II (special controls). The special control for this device is the FDA guidance document entitled “Guidance Document for Vascular Prostheses 510(k) Submissions.”