Search Results

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.

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).

Ask a specific question about this device

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.

Here's an analysis of the provided text regarding the acceptance criteria and supporting studies for the IMPRA ePTFE Arteriovenous Cuffed Graft:

Important Note: The provided document is a 510(k) summary from 1997 for a medical device (vascular graft). It's crucial to understand that the concepts of "acceptance criteria" and "device performance" in the context of this document are primarily focused on demonstrating substantial equivalence to a predicate device, rather than meeting specific quantifiable performance metrics in a standalone, prospective clinical trial with pre-defined statistical endpoints like many modern AI/ML device submissions. The "performance" described relates to comparative outcomes between the new device and the predicate or observations from a clinical use of a similar design.

1. Table of Acceptance Criteria and Reported Device Performance

Given the nature of the 510(k) submission, the "acceptance criteria" are implied by the demonstration of substantial equivalence to the predicate device, particularly in terms of safety and efficacy (patency and complication rates). The document doesn't explicitly state quantitative acceptance criteria in the way a modern AI device might. Instead, it compares the new device (or its template) to the predicate device or established clinical outcomes.

2. Sample Sizes Used for the Test Set and Data Provenance

Given this is a physical medical device, not an AI model, the concept of "test set" and "data provenance" (as typically used for AI) requires interpretation:

• Physical Testing: Not explicitly stated as a "sample size" but implies multiple units for various physical tests.
• Preclinical Testing - Animal Study:
  • Sample Size: Numbers of grafts implanted are not explicitly stated, but it involved multiple IMPRA ePTFE Vascular Grafts and IMPRA ePTFE Arteriovenous Cuffed Grafts in an established sheep model. The context suggests a sufficient number for morphometric analysis and statistical comparison.
  • Data Provenance: Prospective animal study (sheep model).
• Clinical Testing:
  • Sample Size:
    • AVP Group (template device for new device): 174 grafts
    • Conventional Group (control): 50 grafts
  • Data Provenance: Prospective clinical study, conducted at Charite Hospital, Berlin, Germany.

3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications

Again, for a physical device, "ground truth" is established differently than for AI.

• Physical Testing: The "ground truth" is objective measurement against established standards (ANSVAAMI VP20 - 1994, 1993 FDA Draft Guidance). No individual experts "establish ground truth" in the AI sense here.
• Preclinical Testing - Animal Study:
  • Experts: Not explicitly stated how many pathologists or researchers evaluated the explanted grafts.
  • Qualifications: Implied to be qualified researchers/pathologists capable of morphometric analysis and histological characterization.
• Clinical Testing:
  • Experts: Dr. Hans Scholz, Chief of Vascular Surgery, Queen Elisabeth Hospital, Berlin, designed and conducted the study. He is the inventor of the AVP graft.
  • Qualifications: Chief of Vascular Surgery, inventor of the AVP, conducted procedures at Charite Hospital, Berlin. This implies significant surgical and clinical expertise.

4. Adjudication Method for the Test Set

• Adjudication Method: Not applicable in the AI sense of resolving disagreements among multiple human annotators.
  • Physical/Preclinical: Objective measurements and expert interpretation by implied qualified personnel.
  • Clinical: Clinical outcomes were observed and documented by the study investigator. No mention of an independent adjudication committee for clinical events is made, which is common for single-center, investigator-initiated studies from this era.

5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study

• MRMC Study: No, an MRMC comparative effectiveness study was not done. This type of study is typically used for diagnostic devices (especially imaging) where multiple readers interpret cases with and without AI assistance to measure human performance improvement. This device is a vascular graft, not a diagnostic tool.

6. Standalone (Algorithm Only) Performance Study

• Standalone Study: No. This device is a physical vascular graft, not an AI algorithm. Therefore, the concept of "standalone performance" for an algorithm doesn't apply. Its performance is assessed through its physical properties and clinical outcomes when implanted.

7. Type of Ground Truth Used

• Physical Testing: Objective measurements against industry standards and guidance documents.
• Preclinical Testing (Animal Study): Histological analysis and morphometric measurements of explanted grafts and vessels.
• Clinical Testing:
  • Outcomes Data: Primary patency, thrombosis rates, complication rates, and survival data from patients receiving the grafts. This is considered robust clinical ground truth.

8. Sample Size for the Training Set

Again, in the context of this physical device, there isn't a "training set" in the machine learning sense. The device's design and manufacturing processes are developed based on engineering principles, material science, and prior experience with predicate devices or templates.

• The AVP graft, which served as a "template," was informed by the inventor's experience and data. The IMPRA ePTFE Arteriovenous Cuffed Graft was developed using the AVP as a template, meaning the knowledge and design of the AVP (including its clinical results) guided the development of the new device. So, the 174 AVP cases could retrospectively be seen as informing the development of the final IMPRA ePTFE Arteriovenous Cuffed Graft.

9. How the Ground Truth for the Training Set Was Established

As there's no "training set" in the AI sense:

• The "ground truth" that informed the design of the IMPRA ePTFE Arteriovenous Cuffed Graft was the experience and data from the AVP graft. This included:
  • Data from the inventor (Dr. Scholz) regarding cuff angle, length, and width.
  • The clinical experience with the AVP graft (174 cases), which demonstrated its safety and efficacy (patency, thrombosis rates). These clinical outcomes were established through direct medical observation, follow-up, and diagnostic procedures for events like thrombosis.

Ask a specific question about this device