(15 days)
The IMPRA ePTFE Arteriovenous Cuffed Graft is indicated for use as a subcutaneous arteriovenous conduit for blood access.
The IMPRA ePTFE Arteriovenous Cuffed Graft is an expanded polytetrafluoroethylene angioaccess graft [i.e., an IMPRA ePTFE Vascular Graft, the predicate device for this 510(k)] with a modified venous end. The venous end is cuffed, facilitating vessel conformity, a uniform suturing surface, and improved flow through the anastomosis. The IMPRA ePTFE Arteriovenous Cuffed Graft is made from the same materials as the predicate device, i.e., polytetrafluoroethylene (PTFE), lubricant used as a manufacturing aid, a blue pigment used in the orientation lines, and the external support PTFE beading. These grafts are supplied in the same product configurations as the predicate device (straight, stepped, CenterFlex, and stepped CenterFlex), and are packaged, labeled, and sterilized in the same manner as the predicate device.
The provided text outlines the safety and effectiveness of the IMPRA ePTFE Arteriovenous Cuffed Graft, primarily through comparison to a predicate device (IMPRA ePTFE Vascular Graft) and a similar "AVP" device used in a clinical study. However, it does not describe an AI/ML-based device, nor does it present acceptance criteria or a study design in the way an AI/ML product would.
Based on the provided text, I cannot answer questions related to AI/ML device performance, acceptance criteria, test sets, ground truth establishment, or expert involvement as these concepts are not applicable to the medical device described (a vascular graft).
The document focuses on demonstrating substantial equivalence to an existing predicate device, a common pathway for medical device clearance. The "performance" discussed relates to the biological and mechanical performance of the graft itself, not the performance of an AI algorithm.
Therefore, I will extract relevant information about the device's assessment from the provided text, rephrasing the "acceptance criteria" and "study" in the context of a non-AI medical device.
Here's the information parsed from the document, tailored as much as possible to your requested format, but with strong caveats that it's not an AI/ML device:
Device Under Evaluation: IMPRA ePTFE Arteriovenous Cuffed Graft
This document describes a non-AI medical device (a vascular graft). Therefore, many of the requested categories related to AI/ML performance, test sets, ground truth, and expert adjudication are not directly applicable. I will provide information relevant to the device's assessment from the text, interpreting "acceptance criteria" in the context of device performance and safety.
1. Table of Acceptance Criteria and Reported Device Performance
The "acceptance criteria" for this device are primarily based on demonstrating substantial equivalence to a predicate device (IMPRA ePTFE Vascular Graft) and acceptable performance in animal and clinical studies.
| Category | Acceptance Criteria (Implied for Substantial Equivalence and Safety) | Reported Device Performance (IMPRA ePTFE Arteriovenous Cuffed Graft) |
|---|---|---|
| Material | Same materials as predicate device, biocompatible. | Made from same materials: polytetrafluoroethylene (PTFE), lubricant, blue pigment, external support PTFE beading. Biocompatibility (via predicate and cytotoxicity tests) confirmed. |
| Sterilization | Validated sterilization process. | Sterilized with 100% Ethylene Oxide using the overkill method, single-use, but resterilization with steam is validated in Directions for Use. |
| Physical Properties | Meets standards (e.g., ANSI/AAMI VP20 - 1994) and FDA guidance for vascular prostheses, suitable for intended use, strength not compromised by modifications. | Passed testing per ANSI/AAMI VP20 - 1994 and 1993 FDA Draft Guidance. Significant reduction in wall thickness at cuff does not compromise strength (longitudinal, burst, suture retention). |
| Handling | Equivalent or superior handling characteristics compared to predicate. | Animal study showed "performed better, overall" in handling characteristics (needle penetration difficulty, suture drag, suture hole bleeding) compared to predicate. |
| Intimal Hyperplasia | Reduced or comparable intimal hyperplasia formation, indicating improved patency. | Animal study showed: Less intimal area and lower percentage of stenosed area at the venous end (not statistically significant). Statistically significant 50% less average intimal thickness in the toe regions compared to predicate. Concluded to decrease intimal hyperplasia, potentially leading to decreased failure rate and longer patency. |
| Thrombosis Rate | Acceptable or improved thrombosis rate compared to conventional grafts. | Clinical study (with AVP device, similar cuffed design): Overall thrombosis rate of 5.2% for cuffed grafts vs. 16% for conventional grafts. |
| Patency | Acceptable or improved patency rates. | Clinical study (with AVP device): Cumulative primary patencies of 88% at 45 months for AVP grafts vs. 66% at 27 months for conventional prostheses (control). Mean duration of shunt function was comparable. |
| Complications/Safety | No adverse effect on safety (complications) or efficacy (patency); comparable complication rates (excluding thrombosis which was better). No device contribution to patient deaths. | Clinical study (with AVP device): Complications comparable except for thrombosis rate (AVP better) and death rate (AVP 21.8% vs. conventional 12%). Death rate difference attributed to patient comorbidities, not the device. Concluded clinical implantation of AVP graft did not adversely affect safety (complications) or efficacy (patency). |
| Design Differences | Design modifications do not raise new questions of safety or effectiveness. | Cuffed portion is the only technological difference from predicate. Manufacturing process for cuff (one-piece ePTFE) differs from AVP (two ePTFE pieces sutured). This difference in wall thickness (thinner in cuffed graft) does not compromise safety or strength. Demonstrated substantial equivalence. |
2. Sample Size Used for the Test Set and Data Provenance
- Animal Study: The text mentions "eight sheep" were implanted with grafts for the handling assessment. It doesn't specify if the "morphometric analysis" used the same eight or a different number, or how many grafts were implanted per sheep.
- Clinical Study (AVP Graft):
- Test Set (Cuffed Grafts): 174 AVP grafts (constructed from standard 4mm-7mm Stepped IMPRA ePTFE grafts)
- Control Set (Conventional Grafts): 50 conventional 4mm-7mm Stepped IMPRA ePTFE grafts
- Data Provenance: Retrospective for some aspects, but described as patients "entered into this study." All clinical procedures were performed at the Charite Hospital, Berlin, Germany. Between August 1992 to June 1996.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
This question is not applicable as this is a physical medical device, not an AI/ML system requiring expert ground truth for classification or detection.
For the clinical study, the "ground truth" was established by direct clinical observation of patient outcomes:
- Surgical procedures, implantation, and immediate postoperative development were observed.
- Follow-up observations were conducted at intervals of six months, up to the second year.
- Outcomes like patency, thrombosis, other complications, and patient deaths were recorded.
- The study was designed and conducted by Dr. Hans Scholz, Chief of Vascular Surgery, Queen Elisabeth Hospital, Berlin, who was also the inventor of the AVP device. His qualifications (Chief of Vascular Surgery) imply expert medical assessment.
4. Adjudication Method for the Test Set
This question is not applicable. Clinical outcomes were directly observed and recorded by the medical team involved in the study under the direction of Dr. Scholz. There's no mention of an "adjudication method" in the sense of resolving disagreements among multiple experts for a test set, as would be relevant for an AI/ML study.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, an MRMC study was not done. This type of study is specific to evaluating diagnostic devices, often involving multiple human readers assessing cases with and without AI assistance. This document describes a vascular graft.
6. If a Standalone (i.e. algorithm only without human-in-the-loop performance) Was Done
No. This concept is not applicable as the device is a physical vascular graft, not an algorithm.
7. The Type of Ground Truth Used
- Animal Study: Histological analysis (to determine thickness of intimal hyperplasia, degree of luminal narrowing, and cellular characterization), photographs of grafts and adjacent vessels at explant, and direct observation of handling characteristics.
- Clinical Study (AVP Graft): Outcomes data from direct patient observation and follow-up, including:
- Patency rates (cumulative primary patencies)
- Thrombosis rates
- Complication rates
- Mortality rates and causes of death (patient characteristics and comorbidities factored in for death analysis).
- Flow rates through the shunt (between selected patients).
8. The Sample Size for the Training Set
This question is not applicable. There is no AI/ML "training set" for this physical medical device. The "training" for such devices typically involves extensive engineering design, material science, bench testing, and animal studies to refine the product before human clinical trials.
9. How the Ground Truth for the Training Set Was Established
This question is not applicable, as there is no AI/ML training set. The "ground truth" for developing this device was established through standard engineering principles, materials science, preclinical (bench and animal) testing, and prior clinical experience with similar devices (the predicate device and the AVP).
{0}------------------------------------------------
K9711922
Section 510(k)
APR 15 1997
1 185
Summary of Safety and Effectiveness Information
Regulatory Authority: Safe Medical Devices Act of 1990, 21 CFR 807.92
Company Name/Contact
| Company: | IMPRA, A Subsidiary of C. R. Bard, Inc. |
|---|---|
| 1625 West Third Street | |
| Tempe, Arizona 85281 | |
| Contact: | Kristi M. Kistner |
| Regulatory Affairs Manager | |
| Telephone: (602) 894-9515 | |
| Fax: (602) 966-7062 |
Establishment
Registration Number: 2020394
Device Name
| Trade Name: | IMPRA ePTFE Arteriovenous Cuffed Graft |
|---|---|
| Common Name(s): | Vascular Graft Prosthesis |
| Classification Names/Codes: | Vascular graft prostheses of 6 mm and greater diameter(74DSY). |
CONFIDENTIAL
{1}------------------------------------------------
Substantially Equivalent Device
IMPRA ePTFE Vascular Graft
Device Description
The IMPRA ePTFE Arteriovenous Cuffed Graft is an expanded polytetrafluoroethylene angioaccess graft [i.e., an IMPRA ePTFE Vascular Graft, the predicate device for this 510(k)] with a modified venous end. The venous end is cuffed, facilitating vessel conformity, a uniform suturing surface, and improved flow through the anastomosis.
The IMPRA ePTFE Arteriovenous Cuffed Graft is made from the same materials as the predicate device, i.e., polytetrafluoroethylene (PTFE), lubricant used as a manufacturing aid, a blue pigment used in the orientation lines, and the external support PTFE beading. These grafts are supplied in the same product configurations as the predicate device (straight, stepped, CenterFlex, and stepped CenterFlex), and are packaged, labeled, and sterilized in the same manner as the predicate device.
Indication for Use
The IMPRA ePTFE Arteriovenous Cuffed Graft is indicated for use as a subcutaneous arteriovenous conduit for blood access. The predicate device, the IMPRA ePTFE Vascular Graft, is indicated for use in blood access, bypass, or reconstruction of arterial blood vessels.
{2}------------------------------------------------
Packaging
The IMPRA ePTFE Arteriovenous Cuffed Graft is packaged in a double tray configuration and placed inside of a box. The trays are made from either PVC or PETG and are sealed with Tyvek lids. After sterilization, the product Directions for Use is applied to the outside of the box and the assembly is shrinkwrapped prior to being released to inventory.
Sterilization/Re-sterilization
The IMPRA ePTFE Arteriovenous Cuffed Graft is sterilized with 100% Ethylene Oxide prior to being placed into inventory for sale. Validation of the sterilization process is performed using the overkill method.
The IMPRA ePTFE Arteriovenous Cuffed Graft is a single use device, intended for single patient use, only. The Directions for Use for both the IMPRA ePTFE Arteriovenous Cuffed Graft and the predicate device, the IMPRA ePTFE Vascular Graft, allow for resterilization of the graft with steam in the event that a package has been inadvertently opened, and the product has not been damaged or contaminated with blood or any foreign material. The resterilization instructions in the Directions for Use have been validated by IMPRA.
Physical Testing
Device testing was performed on the cuffed portion of the IMPRA ePTFE Arteriovenous Cuffed Graft and compared to the results of testing performed on the IMPRA ePTFE Vascular Graft, The testing was conducted using methods recommended in ANSI/AAMI VP20 - 1994:
CONFIDENTIAL
{3}------------------------------------------------
Cardiovascular implants - Vascular Prostheses and the 1993 FDA Draft Guidance for the Preparation of Research and Marketing Applications for Vascular Graft Prostheses. The results of all testing indicated that the IMPRA ePTFE Arteriovenous Cuffed Graft is suitable for use as a subcutaneous arteriovenous conduit for blood access and the anticipated conditions of use imposed on the device. The results demonstrated that the IMPRA ePTFE Arteriovenous Cuffed Graft has been adequately designed to perform in a manner substantially equivalent to that of the predicate device.
Preclinical Testing - Animal Study
A short-term animal study (8 weeks) was conducted to compare intimal hyperplasia formation in IMPRA ePTFE Vascular Grafts and IMPRA ePTFE Arteriovenous Cuffed Grafts in an established sheep model. Grafts were evaluated at implant for handling characteristics (needle penetration difficulty, suture drag, and suture hole bleeding). At explant, grafts and adjacent vessels were photographed and prepared for histology to determine thickness of intimal hyperplasia, degree of luminal narrowing and cellular characterization.
The handling assessment indicated that the IMPRA ePTFE Arteriovenous Cuffed Graft performed better, overall, than the IMPRA ePTFE Vascular Graft. The morphometric analysis of cross sections through the venous ends of the grafts showed that IMPRA ePTFE Arteriovenous Cuffed Grafts had less intimal area and a lower percentage of stenosed area at the venous end than did the IMPRA ePTFE Vascular Grafts. However, the differences between groups were not statistically significant. The morphometric analysis of sections though the toe regions of the grafts
CONFIDENTIAL
10
【到得】
{4}------------------------------------------------
showed that the IMPRA ePTFE Arteriovenous Cuffed Grafts had 50% less average intimal thickness in this region than did the IMPRA ePTFE Vascular Grafts. This difference was statistically significant.
The conclusion of the study was that the results demonstrated that the addition of a distal cuff decreased intimal hyperplasia at the venous end of the graft. This effect could be expected to result in a decreased failure rate and longer graft patency.
Preclinical Testing - Biocompatibility/Toxicity
IMPRA has completed biocompatibility/toxicity testing on IMPRA ePTFE Vascular Grafts, the predicate device for this 510(k). in accordance with the requirements of ISO Standard 10993. FDA Blue Book Memorandum #G87-1, and Good Laboratory Practices. This testing confirms the biocompatibility of IMPRA ePTFE Vascular Grafts. Additional cytotoxicity testing was conducted on IMPRA ePTFE Arteriovenous Cuffed Grafts (per the guidelines in FDA Blue Book Memorandum #G95-1). The test samples evoked no cytotoxic responses.
Clinical Testing
Clinical testing was performed on a device (AVP) that utilized the same cuffed configuration at the venous anastomosis as the IMPRA ePTFE Arteriovenous Cuffed Graft. The IMPRA ePTFE Arteriovenous Cuffed Graft was developed using the AVP graft as a template. The cuff angle is the same for both devices, and the overall cuff length and width for the IMPRA ePTFE Arteriovenous Cuffed Graft were based on data from the inventor of the AVP.
CONFIDENTIAL
】 I
出版
{5}------------------------------------------------
The primary differences between the two devices are the construction and the wall thickness. The IMPRA ePTFE Arteriovenous Cuffed Graft is manufactured from one piece of expanded PTFE, using no sutures or additional materials. The AVP is made using two ePTFE pieces, sutured together to form the cuff. The wall thickness of the cuffed portion of the IMPRA ePTFE Arteriovenous Cuffed Graft is less than the wall thickness of the cuffed portion of the AVP. This difference in wall thickness is due to the proprietary manufacturing process utilized in the manufacture of the IMPRA ePTFE Arteriovenous Cuffed Graft and does not compromise the safety of the device.
The clinical study was designed and conducted by Dr. Hans Scholz, Chief of Vascular Surgery, Queen Elisabeth Hospital, Berlin. Dr. Scholz is the inventor of the AVP. All clinical procedures were performed at the Charite Hospital, Berlin. Between August 1992 to June 1996, 174 AVP grafts constructed from standard 4 mm to 7 mm Stepped IMPRA ePTFE grafts were implanted as straight AV shunts in the upper arm of patients in need of vascular access for hemodialysis. The AVP grafts used in this study were constructed by the investigator intra-operatively. During the same period, fifty (50) conventional 4 mm to 7 mm Stepped IMPRA ePTFE grafts were also implanted in the upper arm in a non-randomized fashion. Patients were entered into this study only if a native A-V fistula could not be constructed in the arm. Patients were excluded only if they had a known hypercoagulability condition, or had arterial hypotension with systolic values below 100 mm Hg.
No anticoagulants were used during this study. Beginning with patient number 101, intra-
CONFIDENTIAL
{6}------------------------------------------------
operative application of antibiotics (Tarzobac) was instituted as an infection prophylactic.
Observations were recorded at the time of the operation. Follow-up included immediate postoperative development and continued up to the second year after implantation of the prosthesis. Post-operative observations took place at intervals of six months.
Analysis of the results indicated that patient demographics in both groups were comparable with regard to the gender, age, height, weight, mean blood pressure, and number of previous operations.
Life table analysis indicates that the cumulative primary patencies were 88% at 45 months for AVP grafts and 66% at 27 months for the conventional prostheses (control). The mean duration of shunt function was comparable in both groups.
Complications in both groups were comparable except for the number of deaths and the thrombosis rate. The overall thrombosis rates were 5.2% for the AVP group and 16% for the conventional (control) group. There was a 21.8% death rate in the AVP group and a 12% death rate in the conventional group, with the mean time to death in the AVP group longer than the time for the conventional group (23.6 vs. 13.2 months, respectively). The patients that died due to cardiac failure in the AVP group were found to have had significant cardiac and other comorbidities at the time of graft implantation. Comparison of flow rates between selected patients with AVP and conventional grafts at various follow-up times indicated that the AVP graft did not ,一
{7}------------------------------------------------
increase the flow rates through the shunt. It was concluded that the AVP grafts did not contribute to the deaths of these patients.
The above summary indicates that clinical implantation and use of the AVP graft did not adversely affect the safety (complications) or efficacy (patency) when used as a vascular access graft for hemodialysis. The AVP clinical experience evaluates the performance of the cuffed design and supports the safety of the IMPRA ePTFE Arteriovenous Cuffed Graft.
Equivalence
The IMPRA ePTFE Arteriovenous Cuffed Graft is supplied in the same sizes (internal diameter and usable length) and configurations (Straight, CenterFlex, Stepped, and Stepped CenterFlex grafts in standard wall thickness), and is packaged, and sterilized in the same manner as the IMPRA ePTFE Vascular Graft to which substantial equivalence is claimed. The uncuffed portion of the IMPRA ePTFE Arteriovenous Cuffed Graft is the IMPRA ePTFE Vascular Graft. The IMPRA ePTFE Arteriovenous Cuffed Graft is made by further processing the predicate device to create a flared or cuffed end on the venous end of the graft. The cuffed portion of the IMPRA ePTFE Arteriovenous Cuffed Graft is the only technological characteristic that differentiates this device from the IMPRA ePTFE Vascular Graft.
Functionally, the cuffing processes produce a flared segment on the largest diameter end of the graft. This flared end is referred to as the cuff and has the same configuration (angle, length, and width) on all graft sizes and product types. The cuffing processes do not affect the microporous
CONFIDENTIAL
{8}------------------------------------------------
structure of the product, but they do significantly reduce the wall thickness at the cuff. This reduction in wall thickness does not compromise the strength (longitudinal, burst, suture retention) of the IMPRA ePTFE Arteriovenous Cuffed Graft. Also, the handling characteristics (needle penetration, suture drag, suture hole bleeding) of the IMPRA ePTFE Arteriovenous Cuffed Graft were judged to be equivalent or superior to the IMPRA ePTFE Vascular Graft when implanted in eight sheep.
Therefore, it must be concluded that the technological characteristics of this device do not raise any new types of questions of safety or effectiveness. The IMPRA ePTFE Arteriovenous Cuffed Graft has been adequately designed to perform in a manner substantially equivalent to that of the predicate device.
Conclusion
IMPRA ePTFE Arteriovenous Cuffed Grafts and IMPRA ePTFE Vascular Grafts are manufactured in the same ISO 9001:1994 certified facility in Tempe, Arizona. This facility has recently undergone FDA GMP establishment inspections and UK Department of Health inspections. The IMPRA ePTFE Arteriovenous Cuffed Graft utilizes the same validated base graft and secondary processes as the IMPRA ePTFE Vascular Graft. The cuffed portion of the graft is formed with three additional processes after base graft and secondary processes have been completed. These cuffing processes are subject to the same equipment and process qualifications, validations, and quality system requirements as the base graft and secondary processes.
{9}------------------------------------------------
There are no significant differences in design, material, or performance characteristics between the IMPRA ePTFE Arteriovenous Cuffed Graft and the IMPRA ePTFE Vascular Graft that could adversely affect safety or effectiveness. The IMPRA ePTFE Arteriovenous Cuffed Graft is substantially equivalent to the IMPRA ePTFE Vascular Graft.
CONFIDENTIAL
§ 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.”