(120 days)
The FreedomFlow™ Orbital Circumferential Atherectomy System is indicated for use as therapy in patients with occlusive atherosclerotic disease in peripheral arteries. The therapy is intended for patients who are acceptable candidates for percutaneous transluminal atherectomy.
The FreedomFlow™ Orbital Circumferential Atherectomy System is a flexible over-the-wire rotational device used to ablate atherosclerotic plaque from peripheral arterial blood vessels within the body. The FreedomFlow™ System consists of three components: User Handle with integrated driveshaft, Tubing Set, and Power Supply.
The User Handle with the integrated driveshaft is sterile, single use, and disposable. Both 5 Fr and 6 Fr variations of the User Handle are available. The User Handle provides the operator interface to control driveshaft rotation (with two speed options) and translation within the vessel. The User Handle also incorporates a guidewire mechanical clamp. The User Handle controls the saline fluid flow down the driveshaft catheter. The User Handle utilizes firmware and hardware to perform these functions. The Tubing Set is sterile, single use, and disposable. The Tubing Set connects a user provided sterile saline supply to the User Handle. The Tubing Set is connected by the operator to the User Handle. The Power Supply is a medical grade AC powered transformer, supplying DC electrical energy to the User Handle. The power supply is reusable.
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
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Primary Safety Endpoint: Freedom from Major Adverse Events (MAE) at 30 days. Performance Goal: > 85% | Achieved. Rate of freedom from MAE was 92.9% with a lower 95% confidence interval of 86.4%. |
| Primary Effectiveness Endpoint (Original): Technical success defined as the ability to achieve residual diameter stenosis less than 50% without adjunctive therapy. Performance Goal: 86% | Not met. The technical success rate was 67.4% with a lower 95% confidence interval of 58.7%, missing the performance goal of 86%. |
| Primary Effectiveness Endpoint (Supplemental): Mean Post Atherectomy Stenosis (PAS) statistically non-inferior to a PVI Registry Cohort, using an alpha of 0.025 and a non-inferiority margin of 7.0%. | Achieved. The observed PAS was 41.1% ± 19.2% for the FAST II cohort, and 46.2% ± 17.1% for the PVI Registry Cohort. FAST II PAS was demonstrated to be statistically non-inferior to the registry PAS. |
| Non-Clinical Performance Tests: (Dimensional Verification, Kink Resistance, Corrosion Resistance, Heat Generation, Torsional Strength, Tensile Strength, Rotational Speed, Plaque Removal Efficiency, Particulate Evaluation, Infusion Flow Rate, Embolization Analysis, Life Cycle/Fatigue, Orbit Testing, Coating Integrity, Usability Validation, Biocompatibility, Software, Electrical, Sterility, Sterile Barrier Integrity, Shelf life) | All non-clinical tests passed, demonstrating compliance with performance requirements and relevant standards (e.g., FDA guidance for Peripheral Vascular Atherectomy Devices, IEC 60601-1-6, ANSI/AAMI HE75, ISO 10993-1, IEC 62304, IEC 60601-1, IEC 60601-1-2, ANSI/AAMI/ISO 11135, ASTM D4169-16, ASTM F2096-11, ASTM F88). Animal and cadaveric model evaluations also supported pre-clinical safety and effectiveness, including in-vivo thrombogenicity. |
Study Details
2. Sample sizes used for the test set and the data provenance
- FAST II Study (Primary Clinical Study):
- The exact sample size isn't explicitly stated for this part, but it refers to "patients with symptomatic peripheral arterial disease (PAD) of the lower extremities."
- Provenance: Prospective, multi-center, single-arm, open-label clinical study. No specific country of origin is mentioned, but "multi-center" implies multiple locations.
- Supplemental Analysis (Matched Comparison):
- FAST II Cohort: The same patient cohort from the FAST II study.
- PVI Registry Cohort: Real-world evidence obtained from the Vascular Quality Initiative (VQI) Peripheral Vascular Intervention (PVI) registry. This cohort was refined using propensity scoring to identify a control group with well-balanced baseline covariates.
- Provenance: This involves data from a prospective clinical study (FAST II) and retrospective registry data (VQI PVI). The "real-world evidence" suggests a broader, likely multi-national or U.S.-based, data source.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
- For the "raw data (i.e., arteriographic images) from the cohort registry and the FAST II study," an independent angiographic core-laboratory was used for blinded analysis.
- The number and specific qualifications of experts within this core-laboratory are not explicitly detailed in the provided text.
4. Adjudication method for the test set
- For the supplemental effectiveness analysis, the "raw data (i.e., arteriographic images)" were "randomized for blinded analysis by an independent angiographic core-laboratory." This implies a blinded, independent review process. The specific number of readers or a 2+1, 3+1 method is not stated, but the "core-laboratory" typically suggests a robust, structured review process.
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 involving human readers with and without AI assistance was not mentioned or performed. This submission is for an atherectomy system (a physical medical device) and its associated firmware, not a diagnostic AI system designed to assist human readers in interpreting images.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
- No, this is not applicable. The FreedomFlow Orbital Circumferential Atherectomy System is a physical medical device. While it includes firmware (software), the studies described evaluate the device's clinical and non-clinical performance, not the standalone performance of an algorithm that generates an interpretation or diagnosis without human interaction.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
- Clinical Outcomes Data: The primary safety endpoint (freedom from MAE) and primary effectiveness endpoints (technical success, Post Atherectomy Stenosis) are based on direct clinical outcomes measured in patients.
- Expert Adjudication: For the effectiveness endpoint, residual diameter stenosis was determined by an "independent angiographic core-laboratory," which implies expert consensus based on angiographic images.
8. The sample size for the training set
- Not applicable/Not provided. This information pertains to machine learning models. The studies described are evaluating a physical medical device, not training a machine learning model for diagnostic or predictive purposes where a distinct training set would be required for the evaluation itself. The "propensity scoring" used in the supplemental analysis to "refine" and "identify a control cohort" from the PVI registry is a statistical matching technique, not a machine learning training process in the sense of an algorithm.
9. How the ground truth for the training set was established
- Not applicable/Not provided. As there is no described training set for a machine learning model in this context, the method for establishing its ground truth is not relevant here.
§ 870.4875 Intraluminal artery stripper.
(a)
Identification. An intraluminal artery stripper is a device used to perform an endarterectomy (removal of plaque deposits from arterisclerotic arteries.)(b)
Classification. Class II (performance standards).