(184 days)
The NxStage System One is indicated for the treatment of acute and chronic renal failure or fluid overload using hemofiltration, hemodialysis, and/or ultrafiltration, in an acute or chronic care facility. The NxStage System One is also indicated for hemodialysis with or without ultrafiltration in the home.
All treatments must be administered under physician's prescription, and must be observed by a trained and qualified person, considered to be competent in the use of this device by the prescribing physician.
The NxStage System One dialysis system consists of an electro-mechanical cycler and a disposable Cartridge Extracorporeal Blood and Fluid Circuit (NxStage Cartridge). The NxStage Cartridge is available with a pre-attached high permeability dialyzer, together referred to as the "NxStage Cartridge Express".
The NxStage Cartridge Express filter is made up of a fiber bundle maintained within a polyethylene terephthalate glycol (PETG) dialyzer housing. The polysulfone fiber bundle is a semipermeable, hollow fiber membrane through which water molecules and smaller molecular weight solutes pass from the blood to the dialysate, but larger molecular weight solutes (such as proteins) do not. Uremic toxins and waste products are removed from the patient's blood by means of diffusion during hemodialysis.
The NxStage System One with Cartridge Express (CAR-170-E and CAR-172-E) received a 510(k) clearance (K232803) for the treatment of acute and chronic renal failure or fluid overload using hemofiltration, hemodialysis, and/or ultrafiltration. This device is an updated version of the legally marketed predicate device, NxStage System One with Cartridge Express (K061837). The device is a gamma-sterilized, single-use device, and the dialyzer is provided with the blood pathway sterile and nonpyrogenic.
Here's an analysis of the acceptance criteria and study details:
1. Acceptance Criteria and Reported Device Performance
The submission indicates that performance testing was conducted according to ISO 8637-1 First Edition 2017-11 and the FDA's "Guidance for the Content of Premarket Notifications for Conventional and High Permeability Hemodialyzers, August 1998." All testing met predetermined acceptance criteria, demonstrating that the NxStage Cartridge Express is safe and effective for its intended use, similar to the predicate device.
Specifically, key performance indicators for dialyzers are Urea, Creatinine, and Vitamin B12 clearance. The provided table details the in vitro clearance performance data for various blood and dialysate flow rates. Additionally, ultrafiltration rate information is presented for different transmembrane pressures.
| Performance Characteristic | Acceptance Criteria (Implied by Predicate Equivalence and Industry Standards) | Reported Device Performance (In Vitro Clearance Data) |
|---|---|---|
| Clearance (mL/min, QUF=0 mL/min) | Must be comparable to or better than the predicate device and meet clinical needs for renal failure treatment. | Specific values are provided for different flow rates: |
| QD=100 mL/min, QB=200 mL/min | ||
| Urea | 100 | |
| Creatinine | 97 | |
| Vitamin B12 | 84 | |
| QD=100 mL/min, QB=300 mL/min | ||
| Urea | 100 | |
| Creatinine | 100 | |
| Vitamin B12 | 92 | |
| QD=100 mL/min, QB=400 mL/min | ||
| Urea | 100 | |
| Creatinine | 99 | |
| Vitamin B12 | 95 | |
| QD=200 mL/min, QB=400 mL/min | ||
| Urea | 195 | |
| Creatinine | 182 | |
| Vitamin B12 | 138 | |
| QD=200 mL/min, QB=500 mL/min | ||
| Urea | 199 | |
| Creatinine | 186 | |
| Vitamin B12 | 143 | |
| Ultrafiltration Rate (Quf in mL/min) | Must be comparable to or better than the predicate device across a range of Transmembrane Pressures (TMP). | Graph provided (Figure 1), showing Quf at various Qb rates (200, 300, 400, 500, 600) across TMP from 0 to 600 mmHg. |
| Structural Integrity | Acceptance of predefined criteria in positive and negative pressure decay testing and blood compartment integrity (membrane integrity). | Testing met predetermined acceptance criteria. |
| Biocompatibility | Meeting ISO 10993-1:2018 standards and no new concerns raised in toxicological risk assessment. | Testing performed to ISO 10993-1:2018 standards, including extractables/leachables, cytotoxicity, sensitization, irritation, systemic toxicity, and hemocompatibility assays. No new biocompatibility concerns were raised. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the specific sample sizes for the "test set" in terms of number of devices or experimental replicates for the performance and structural integrity testing. However, it indicates these were in vitro tests using bovine blood for ultrafiltration rate measurements (Hct. 32%; Total Protein 6 gm/dL; Temperature 37° C). The data provenance is described as in vitro testing. It does not mention any specific country of origin for the data provided from the in-vitro studies.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
Not applicable. The reported performance data appears to be based on objective, quantitative in vitro measurements, not on expert assessment of images or interpretations that would require a "ground truth" established by experts.
4. Adjudication Method for the Test Set
Not applicable, as this was not an expert-based subjective assessment.
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
Not applicable. This device is a medical hardware/disposable (dialysis cartridge), not an AI-powered diagnostic or assistive tool for human readers. No MRMC study was mentioned or would be relevant.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This is not an algorithm-only device.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
The "ground truth" in this context refers to the objectively measured values from the in vitro performance and structural integrity tests of the dialyzer (e.g., measured clearance rates of specific molecules, ultrafiltration rates, integrity test results). Biocompatibility was assessed against established ISO standards.
8. The Sample Size for the Training Set
Not applicable. This device is hardware and does not utilize a "training set" in the sense of machine learning algorithms.
9. How the Ground Truth for the Training Set Was Established
Not applicable for the reasons stated above.
§ 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.”