(147 days)
The Aquadex FlexFlow® System is indicated for:
Continuous ultrafiltration therapy for temporary (up to 8 hours) or extended (longer than 8 hours in patients who require hospitalization) use in adult and pediatic patients weighing 20 kilograms or more whose fluid overload is unresponsive to medical management, including diuretics.
All treatments must be administered by a healthcare provider, within an outpatient clinical setting, under physician prescription, both of whom having received training in extracorporeal therapies.
The Aquadex FlexFlow system comprises the following components:
- . Aquadex FlexFlow console, microprocessor-controlled
- . Blood Circuit Set with integral hemofilter, disposable
- . Venous access catheter
The Aquadex FlexFlow console includes a blood pump, ultrafiltrate pump, control panel, weight scale, air detector, blood leak detector, electrical connectors for the circuit pressure sensors, and mechanical interfaces that hold the circuit in place. The console controls the rate at which the blood pump removes blood from the patient, and the clinician sets the maximum rate at which the ultrafiltrate pump extracts ultrafiltrate from the blood. Patient access is obtained either peripherally or through the central venous veins. Blood is withdrawn from a vein and passes through a withdrawal pressure sensor before entering the blood pump tubing loop. The rotating rollers propel the blood through the the air detector, then into the hemofilter before being returned to the patient. The console screen displays information to help the clinician prime, set up, and operate the system. All system alarm limits are set by the console.
The Aquadex FlexFlow blood circuit is a preassembled, sterile (EtO), single-patient use set. There are two models of the blood circuit: A06162 and A06163. The blood circuit set A06162 consists of a filter, tubing, pressure sensors, connectors, pinch clamps, a priming spike, an ultrafiltrate connecting bag and data key. The blood circuit set A06163 has the same components, except that it also has an inline blood chamber for use in monitoring the patient's hematocrit (Hct) during therapy.
CHF Solutions Inc. offers a dual lumen extended length catheter (dELC) for use with the Aquadex FlexFlow System. The catheter is a peripheral venous access device with stainless steel coil reinforcement. The venous access catheter was not reviewed in K192756 as it was already cleared for safe and effective use under K041791 with no changes since the original clearance affecting its safety and effectiveness.
The provided text describes acceptance criteria and the study conducted to prove the device, the Aquadex FlexFlow System 2.0, meets these criteria.
1. Table of Acceptance Criteria and Reported Device Performance
Device: Aquadex FlexFlow System 2.0
| Acceptance Criteria | Reported Device Performance |
|---|---|
| Fluid Removal Accuracy | Met the design specifications and remained accurate within ±10% when comparing the displayed and actual ultrafiltration amount. Statistically comparable to the PrismaFlex System across all test scenarios. |
| Treatment Course Survival Rate | 100% (No patient deaths during therapy with Aquadex). |
| Hospital Survival Rate | 71% (Eight patients died after therapy but prior to hospital discharge, none related to the device). |
| Complications Associated with Treatment Initiation | No complications reported. |
| Complications During Therapy | Infrequent, occurring in 11 cases (12% of circuits). Most common were clot in the filter and hypotension. |
| Serious Adverse Events or Device-Related Adverse Events | No patient experienced a serious adverse event or device-related adverse event. |
| Design Specifications (General) | Met all acceptance criteria. |
| Biocompatibility | Met ISO 10993 requirements. |
| Electrical Safety | Met IEC 60601 standard. |
| Electromagnetic Compatibility | Met IEC 60601-1-2 standard. |
| Essential Performance | Met IEC 60601-2-16 requirements. |
| Software Verification and Validation | Met FDA's "Guidance for the Content of Premarket Submission for Software Contained in Medical Device's". |
| Performance Testing (General) | Met ISO 8637-1. |
| Human Factors Testing | Met IEC 62366-1, 62366-2 and FDA's Guidance "Applying Human Factors and Usability Engineering to Optimize Medical Device Design." |
2. Sample Size and Data Provenance for the Test Set
The reported clinical data for the clarified indication for use (which seems to function as the "test set" for real-world performance) comes from:
- Sample Size: 93 Aquadex blood circuits were used on 26 pediatric patients (21 years or younger) weighing 20 kilograms or more from 28 hospitalizations.
- Data Provenance: This was a retrospective study conducted in three centers (countries not specified, but likely within the US given FDA submission). The study was performed by investigators independent of the manufacturer.
For the bench performance testing comparing the Aquadex systems and Prismaflex, the "test set" details are not explicitly given as a patient count but involved "all three systems" being tested "at the same therapy settings" to derive a direct comparison of fluid removal accuracies. This implies a controlled laboratory environment rather than patient data for this specific comparison.
3. Number of Experts and Qualifications for Ground Truth for the Test Set
For the retrospective clinical study:
- The text does not explicitly state the number of experts used to establish ground truth or their specific qualifications (e.g., radiologist with 10 years of experience).
- However, it does mention that "All treatments must be administered by a healthcare provider, within an outpatient clinical setting, under physician prescription, both of whom having received training in extracorporeal therapies." This implies that the initial assessment and treatment decisions were made by qualified healthcare professionals and physicians. The independent investigators who analyzed the retrospective data would also be experts in their field.
4. Adjudication Method for the Test Set
The adjudication method is not explicitly stated in the provided text. For the retrospective clinical study data, it's implied that the clinical outcomes were observed and reported, but a formal adjudication process (like 2+1 or 3+1 for discrepancies) by a panel of experts is not described.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was done. The device is a physical medical device (ultrafiltration system), not an AI-powered diagnostic tool that assists human readers. Therefore, the concept of "how much human readers improve with AI vs without AI assistance" does not apply here.
6. Standalone (Algorithm Only) Performance
Not applicable. The Aquadex FlexFlow System 2.0 is a medical device for ultrafiltration therapy, not an algorithm. Its performance is evaluated through its physical function, accuracy, and clinical outcomes, not as an "algorithm only" product. Bench testing was performed on the device itself, not a separate algorithm.
7. Type of Ground Truth Used
- For the bench performance testing (fluid removal accuracy), the ground truth was based on measured actual ultrafiltration amount in a controlled laboratory setting.
- For the retrospective clinical study, the ground truth was based on clinical outcomes data (treatment course survival, hospital survival, complications, adverse events) as observed and recorded by healthcare providers during routine patient care.
8. Sample Size for the Training Set
The document does not mention a training set as this product is a physical medical device and not an AI/ML algorithm that requires training data. The study primarily focuses on verifying the device's performance against specifications and clinical safety/effectiveness.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as no training set (in the context of AI/ML) is mentioned or implied.
§ 876.5860 High permeability hemodialysis system.
(a)
Identification. A high permeability hemodialysis system is a device intended for use as an artificial kidney system for the treatment of patients with renal failure, fluid overload, or toxemic conditions by performing such therapies as hemodialysis, hemofiltration, hemoconcentration, and hemodiafiltration. Using a hemodialyzer with a semipermeable membrane that is more permeable to water than the semipermeable membrane of the conventional hemodialysis system (§ 876.5820), the high permeability hemodialysis system removes toxins or excess fluid from the patient's blood using the principles of convection (via a high ultrafiltration rate) and/or diffusion (via a concentration gradient in dialysate). During treatment, blood is circulated from the patient through the hemodialyzer's blood compartment, while the dialysate solution flows countercurrent through the dialysate compartment. In this process, toxins and/or fluid are transferred across the membrane from the blood to the dialysate compartment. The hemodialysis delivery machine controls and monitors the parameters related to this processing, including the rate at which blood and dialysate are pumped through the system, and the rate at which fluid is removed from the patient. The high permeability hemodialysis system consists of the following devices:(1) The hemodialyzer consists of a semipermeable membrane with an in vitro ultrafiltration coefficient (K
uf ) greater than 8 milliliters per hour per conventional millimeter of mercury, as measured with bovine or expired human blood, and is used with either an automated ultrafiltration controller or anther method of ultrafiltration control to prevent fluid imbalance.(2) The hemodialysis delivery machine is similar to the extracorporeal blood system and dialysate delivery system of the hemodialysis system and accessories (§ 876.5820), with the addition of an ultrafiltration controller and mechanisms that monitor and/or control such parameters as fluid balance, dialysate composition, and patient treatment parameters (e.g., blood pressure, hematocrit, urea, etc.).
(3) The high permeability hemodialysis system accessories include, but are not limited to, tubing lines and various treatment related monitors (e.g., dialysate pH, blood pressure, hematocrit, and blood recirculation monitors).
(b)
Classification. Class II. The special controls for this device are FDA's:(1) “Use of International Standard ISO 10993 ‘Biological Evaluation of Medical Device—Part I: Evaluation and Testing,’ ”
(2) “Guidance for the Content of 510(k)s for Conventional and High Permeability Hemodialyzers,”
(3) “Guidance for Industry and CDRH Reviewers on the Content of Premarket Notifications for Hemodialysis Delivery Systems,”
(4) “Guidance for the Content of Premarket Notifications for Water Purification Components and Systems for Hemodialysis,” and
(5) “Guidance for Hemodialyzer Reuse Labeling.”