(528 days)
The Ellipsys® System is indicated for the creation of a proximal radial artery to perforating vein anastomosis via a retrograde venous access approach in patients with a minimum vessel diameter of 2.0mm and less than 1.5mm of separation between the artery and vein at the fistula creation site who have chronic kidnev disease requiring dialysis.
The Ellipsys® Vascular Access System is a catheter based system that is used to percutaneously create a vascular anastomosis between adjacent blood vessels using direct current (DC) thermal heating. The system consists of several components:
- Ellipsys Catheter ●
- Ellipsys Crossing Needle
- Ellipsys Power Controller ●
Here's a breakdown of the acceptance criteria and the study proving the Ellipsys Vascular Access System meets them, based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria (from Primary Endpoints & Special Controls) | Reported Device Performance (Clinical Study - ITT Population) |
|---|---|
| Safety: | |
| No device-related serious adverse events (SAEs) including: | Primary Safety Endpoint Met (0.0%) (Table 9) |
| - Vessel perforation during index | 0.0% (N=0) |
| - Vessel dissection during index | 0.0% (N=0) |
| - Electrical shock during index | 0.0% (N=0) |
| - Embolization in previously uninvolved arterial territory | 0.0% (N=0) |
| Effectiveness: | |
| 90-day maturation success rate > 49% (Performance Goal) | 89.3% (Table 10); p-value 4 mm |
| - Blood flow > 500 ml/min | Achieved within the 89.3% success rate. |
| Other Performance Indicators: | |
| Device Success Rate | 99.0% (Table 12) |
| Assisted Primary Patency Rate (at 12 months) | 81% (Figure 7, Table 24) |
| Average Estimated Study Days AVF Used for Hemodialysis | 228.3 days (Table 14) |
| Functional AVF at 12 Months | At least 72.8% of ITT subjects (61/103 used for hemodialysis, 14/103 functional but not used) (Table 16) |
| Rate of device-related harmful events through 12 months | 0% |
| Rate of serious procedure-related harmful events through 12 months | 1.9% (2/103) (Benefit/Risk Determination section) |
| Percentage of MAPs not associated with any adverse events | 94.5% (Table 23) |
2. Sample Size Used for the Test Set and Data Provenance
The primary clinical study supporting the Ellipsys Vascular Access System was a non-randomized, prospective multi-center study.
- Test Set Sample Size: The Intent-to-Treat (ITT) population, which primarily serves as the test set for the clinical endpoints, consisted of 103 patients.
- Data Provenance: The study was conducted in the United States.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Their Qualifications
The document does not explicitly state that experts established a "ground truth" for the test set in the traditional sense of image interpretation or diagnostic performance. Instead, the clinical study relied on direct measurements and clinical outcomes:
- Maturation definition (effectiveness endpoint): Venous diameter > 4 mm and blood flow > 500 ml/min, measured by duplex ultrasound. This is an objective measurement, not requiring expert consensus for a "ground truth" assessment of the definition itself.
- Safety endpoints: Defined as absence of specific device-related SAEs. These were adjudicated by an independent medical monitor. The qualifications of this monitor are not detailed beyond "independent medical monitor."
- Ultrasound measurements: Performed by clinical staff trained in ultrasound. No specific expert qualifications (e.g., radiologist with X years of experience) are provided for the individuals performing these measurements or interpreting them for the study.
4. Adjudication Method for the Test Set
- Adverse Events (AEs): All adverse events were adjudicated by an independent Medical Monitor. The method (e.g., single review, consensus) beyond "by an independent Medical Monitor" is not specified.
- Study Data: All study data were monitored by an independent study monitor.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done
No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. The clinical study was designed to compare the device's performance against a historical performance goal for surgical AVF procedures, not against human readers with or without AI assistance in a diagnostic context.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study Was Done
This device is not an AI algorithm for diagnostic purposes. It is a medical device for creating a fistula. Therefore, a standalone (algorithm only) performance study as typically understood for AI diagnostics was not applicable or performed. The "standalone" performance here refers to the device itself performing its intended function without human intervention in the fistula creation process (beyond the physician's use of the device), which is addressed by the device success rate (99.0%).
7. The Type of Ground Truth Used
The "ground truth" for the clinical study's endpoints was based on:
- Objective Clinical Measurements:
- Venous diameter > 4 mm and blood flow > 500 ml/min (for maturation) as measured by duplex ultrasound.
- Direct observation of various adverse events (e.g., vessel perforation, dissection, electrical shock).
- Clinical Outcomes/Events: Patency, need for intervention (MAPs), ability to support 2-needle cannulation, CVC usage, and patient survival.
- Independent Adjudication: Safety events were adjudicated by an independent medical monitor.
8. The Sample Size for the Training Set
The document describes a clinical study to evaluate the device, not an AI system that requires a separate training set. Thus, there is no "training set" sample size for an AI algorithm in this context. The animal studies and bench testing can be considered analogous to early-stage development and testing, but not a "training set" as defined for AI.
9. How the Ground Truth for the Training Set Was Established
As there is no AI training set, this question is not applicable. For the animal studies, the "ground truth" about the fistulae created and safety aspects was established through:
- Direct observation: Acute and post-treatment assessments, gross necropsy.
- Imaging: Ultrasound to determine fistula diameter, patency, and flow.
- Histopathological examination: To evaluate chronic safety and healing response at the fistula and downstream organs.
§ 870.1252 Percutaneous catheter for creation of an arteriovenous fistula for hemodialysis access.
(a)
Identification. This device is a single use percutaneous catheter system that creates an arteriovenous fistula in the arm of patients with chronic kidney disease who need hemodialysis.(b)
Classification. Class II (special controls). The special controls for this device are:(1) Clinical performance testing must evaluate:
(i) The ability to safely deliver, deploy, and remove the device;
(ii) The ability of the device to create an arteriovenous fistula;
(iii) The ability of the arteriovenous fistula to attain a blood flow rate and diameter suitable for hemodialysis;
(iv) The ability of the fistula to be used for vascular access for hemodialysis;
(v) The patency of the fistula; and
(vi) The rates and types of all adverse events.
(2) Animal testing must demonstrate that the device performs as intended under anticipated conditions of use. The following performance characteristics must be assessed:
(i) Delivery, deployment, and retrieval of the device;
(ii) Compatibility with other devices labeled for use with the device;
(iii) Patency of the fistula;
(iv) Characterization of blood flow at the time of the fistula creation procedure and at chronic followup; and
(v) Gross pathology and histopathology assessing vascular injury and downstream embolization.
(3) Non-clinical performance testing must demonstrate that the device performs as intended under anticipated conditions of use. The following performance characteristics must be tested:
(i) Simulated-use testing in a clinically relevant bench anatomic model to assess the delivery, deployment, activation, and retrieval of the device;
(ii) Tensile strengths of joints and components;
(iii) Accurate positioning and alignment of the device to achieve fistula creation; and
(iv) Characterization and verification of all dimensions.
(4) Electrical performance, electrical safety, and electromagnetic compatibility (EMC) testing must be performed for devices with electrical components.
(5) Software verification, validation, and hazard analysis must be performed for devices that use software.
(6) All patient-contacting components of the device must be demonstrated to be biocompatible.
(7) Performance data must demonstrate the sterility of the device components intended to be provided sterile.
(8) Performance data must support the shelf life of the device by demonstrating continued sterility, package integrity, and device functionality over the identified shelf life.
(9) Labeling for the device must include:
(i) Instructions for use;
(ii) Identification of system components and compatible devices;
(iii) Expertise needed for the safe use of the device;
(iv) A detailed summary of the clinical testing conducted and the patient population studied; and
(v) A shelf life and storage conditions.