FDA 510(k) Search - By Innolitics (SaMD and AI Experts)

VasQ is a nitinol implant that is used to provide external support for arteriovenous fistulas (AVF) created by means of vascular surgery. VasO is comprised of a braid and a brace that are welded together (Figure 1). The braid is woven nitinol mesh that provides structural support to the segment of the vein that must be mobilized from its natural supporting tissue to allow surgical anastomosis to the artery. The brace is a laser cut nitinol structure intended to maintain geometric properties at the juxta-anastomosis region of the AVF.

AI/ML Overview

The VasQ device, an extravascular support for arteriovenous fistulas, was assessed through a pivotal clinical study and various non-clinical tests.

1. Table of Acceptance Criteria & Reported Performance:

Acceptance Criteria (from "Special Controls" and "PERFORMANCE TESTING - BENCH")	Reported Device Performance (from "Results" and "PERFORMANCE TESTING - BENCH")
Clinical Performance:
(ii) Ability to achieve blood flow rate and diameter suitable for hemodialysis	Maturation (82.1% at 3 months, 89.3% at 6 months, 92.4% at 12 months, 93.5% at 24 months). Defined as vein diameter ≥5mm and blood outflow ≥500 mL/min.
(iii) Ability of the fistula to be used for vascular access	1st Successful Cannulation (62.8% at 3 months, 82.9% at 6 months, 88.3% at 12 & 24 months). Continuous AVF Use (43.3% at 3 months, 72.5% at 6 months).
(iv) Primary, assisted primary, and secondary patency	Primary Patency: 65.8% (main cohort) / 65.7% (total cohort) at 6 months.
Assisted Primary Patency: 85.1% at 6 months, 78.5% at 12 months, 70.5% at 24 months.
Secondary Patency: 88.8% at 6 months, 84.7% at 12 months, 76.6% at 24 months.
(v) Rates and types of device integrity events and clinical sequelae	Device fractures: 10 observed (no clinical sequelae attributed).
Braid-brace separation: 5/51 (earlier model), 3 detected during implantation, 2 on X-ray (no clinical sequelae attributed). Eliminated in later models.
(vi) Rates and types of all adverse events	Surgical Site Infection: 0.7% (0.0% - 3.8%) at 6 months.
Seroma: 0.0% (0.0% - 2.5%) at 6 months.
Steal: 2.1% (0.4% - 6.0%) at 6 months.
(Pseudo)aneurysm: 0.0% (0.0% - 2.5%) at 6 months.
(vii) Rates and outcomes of reinterventions	Mean time to first intervention: 208 days.
Rate of interventions: 0.97 per patient-year (first 6 months), 1.11 per patient-year (primary analysis set), 1.04 per patient-year (secondary analysis set).
Total post-intervention success rate: 90.8%.
Non-clinical Performance (Bench Testing):
Dimensional Verification: Braid length and welding distance within specified engineering tolerances.	Test passed.
Flex/Kink Resistance: Geometric recovery and kink radius of (b)(4) mm.	Test passed.
Crush Resistance: Full geometric recovery after crushing to (b)(4) of original diameter.	Test passed.
Local Compression: Full geometry recovery after (b)(4) geometric displacement due to local compression.	Test passed.
Device Integrity: Freedom from surface cracks or scratches.	Test passed.
Tensile Strength: Joint at braid-brace must withstand (b)(4) tensile force.	Test passed.
Corrosion Resistance: Assessment of susceptibility to corrosion.	Test passed.
Durability: No breakage after (b)(4) cyclic radial loads.	Test passed.
Bending Fatigue: No clinically significant fracture after (b)() years of simulated in vivo bending.	Test passed.

2. Sample Size for the Test Set and Data Provenance:

Sample Size for Clinical Test Set:
- Total Enrolled: 144 subjects (129 in main cohort for brachiocephalic fistula (BCF), 15 in supplementary cohort for forearm AVF).
- Evaluated for Primary Endpoint (6-month primary patency): 134 subjects (120 in main cohort).
Data Provenance: Prospective, multi-center, single-arm, open-label study conducted at 15 US sites.

3. Number of Experts Used to Establish Ground Truth for Test Set & Qualifications:

The document does not explicitly state the number and qualifications of experts formally establishing "ground truth" for the clinical endpoints (e.g., patency, maturation).
However, it mentions:
- Core laboratory evaluation: For X-ray imaging (device integrity observations like brace breakage, braid/brace detachment).
- Independent Clinical Events Committee and Data Safety Monitoring Board: Reviewed safety events.
- Study site's standard of care: Used for baseline vessel diameter measurements.
- Doppler ultrasound and clinical assessment: Used for confirming fistula patency.

4. Adjudication Method for the Test Set:

The document explicitly mentions:
- "Safety events were reviewed by an independent Clinical Events Committee and Data Safety Monitoring Board." This implies an adjudication process for safety events.
For effectiveness endpoints like primary patency defined by Doppler ultrasound or clinical assessment, the adjudication method is not explicitly detailed but would likely involve established protocols for these assessments within the multi-center study.

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

No, an MRMC comparative effectiveness study was NOT done in the primary clinical study.
The pivotal study was a single-arm study without a control group.
The sponsor did conduct propensity-matched comparative analyses against historical controls (Medicare beneficiary data and retrospective chart review data), but these were not MRMC studies and did not involve human readers using AI assistance. These were comparisons of device outcomes against historical standard-of-care outcomes.
Effect Size of Human Readers with AI vs. without AI: Not applicable, as no MRMC study with AI assistance was performed.

6. Standalone Performance Study (Algorithm Only):

Not applicable. The device is a physical implant (extravascular support), not an algorithm or AI software. The performance studies described evaluate the device's physical and functional performance in in-vivo and in-vitro settings.

7. Type of Ground Truth Used:

Clinical Endpoints: Defined by objective criteria such as:
- Doppler ultrasound measurements: For flow rates and vessel diameters (e.g., for primary patency, maturation).
- Clinical assessments: Palpable thrill, audible bruit (for primary patency).
- Patient outcomes: Receiving dialysis through the fistula (for primary patency), intervention data, adverse event occurrences.
- X-ray imaging: For device integrity observations (evaluated by a core laboratory).
Animal Study Endpoints: Angiography findings, histopathologic evaluation.
Bench Test Endpoints: Direct measurements against engineering tolerances, visual inspection, mechanical testing results.

8. Sample Size for the Training Set:

Not applicable. This device is a physical implant, not an AI/ML algorithm that requires a training set. The clinical study was a pivotal study for device approval, not a dataset for training a model.

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

Not applicable. (See point 8 above).

Summary

Regulation Number and Section

N/A