(199 days)
The Ureteral Stent is intended to facilitate drainage from the kidney to the bladder via placement endoscopically, fluoroscopically or during an open surgical procedure by a trained physician.
The Tria™ Firm Ureteral Stent is intended to facilitate drainage from the kidney to the bladder via placement endoscopically or fluoroscopically or during an open surgical procedure. It is constructed of the same Percuflex polymer as other stents currently marketed by BSC. Tria Firm utilizes a modified extrusion process to provide ureteral stents with an ultra-smooth surface topography.
The Tria™ Firm stent has a double pigtail design and utilizes the same monofilament retrieval lines that are used on other BSC ureteral stents. Tria Firm is packaged with a standard straight stent positioner and a pigtail straightener that are currently provided with other ureteral stents marketed by Boston Scientific.
The purpose of the Tria™ Firm Ureteral Stent is to provide physicians with a product that is aimed at addressing accumulation of urine salt deposits during indwelling. The proprietary surface technology on both the outside and inside of the stent provides maximum coverage from calcium and magnesium salt deposition.
This document is a Premarket Notification (510(k)) for a medical device, the Tria™ Firm Ureteral Stent. It describes the device, its intended use, and why it is considered substantially equivalent to existing devices.
Crucially, this type of FDA submission (510(k)) primarily focuses on demonstrating substantial equivalence to a predicate device rather than proving clinical effectiveness through extensive clinical trials with acceptance criteria for specific outcomes, especially in the context of an AI/algorithm-driven device performance study.
Therefore, most of the requested information regarding acceptance criteria, sample sizes for test/training sets, expert adjudication, MRMC studies, and ground truth establishment for an AI/algorithm is not applicable or present in this document.
The document does mention performance testing for the physical device itself (ureteral stent) and an in vitro study related to a claim about reduced salt accumulation.
Here's an analysis based on the provided document, with explanations for why much of your query cannot be answered:
Analysis of the Provided Document Regarding Device Acceptance and Study
This document describes the regulatory submission for a physical medical device (Tria™ Firm Ureteral Stent), not an AI/algorithm. Thus, the "acceptance criteria" discussed are primarily regulatory in nature (e.g., demonstrating substantial equivalence, biocompatibility, structural integrity, and flow rate of the stent), rather than performance metrics for an AI's diagnostic or predictive capabilities.
The study mentioned is an in vitro test, not a clinical study on human subjects or an AI performance study.
Information Extracted from the Document:
- A table of acceptance criteria and the reported device performance:
- The document does not provide a clear, quantifiable table of acceptance criteria for "device performance" in the way you'd expect for an AI/algorithm (e.g., sensitivity, specificity, AUC). Instead, it lists types of performance tests for the physical stent.
- The closest to a quantifiable performance statement is for the in vitro test on salt accumulation.
| Acceptance Criteria Category (Derived) | Specific Test/Characteristic | Reported Performance/Finding |
|---|---|---|
| Material Properties | Surface Topography | Ultra-smooth surface (modified extrusion process) |
| Functional Performance | Bladder coil length | Tested (results not quantified in summary) |
| Renal coil length/shape | Tested (results not quantified in summary) | |
| Working length | Tested (results not quantified in summary) | |
| Flow rate | Tested (results not quantified in summary) | |
| MRI safety assessment | Tested (results not quantified in summary) | |
| Structural Integrity | Removal force (tensile strength) | Tested (results not quantified in summary) |
| Retrieval line to stent shaft tensile | Tested (results not quantified in summary) | |
| Column strength | Tested (results not quantified in summary) | |
| Biological Safety (Biocompatibility) | Cytotoxicity | Tested (passed, implied by approval) |
| Sensitization | Tested (passed, implied by approval) | |
| Irritation | Tested (passed, implied by approval) | |
| Acute Systemic Toxicity | Tested (passed, implied by approval) | |
| Muscle Implantation | Tested (passed, implied by approval) | |
| Material Mediated Pyrogenicity | Tested (passed, implied by approval) | |
| Chemical analysis extractables | Tested (passed, implied by approval) | |
| Risk assessment of potential toxicity | Tested (passed, implied by approval) | |
| Specific Claim Performance (In Vitro) | Minimizing accumulation of urine calcium and magnesium salts (with and without bacteria) | "Statistically significant lower level of urine calcium and magnesium salt accumulation on the stent surface compared to competitive devices." |
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Sample sizes used for the test set and the data provenance:
- Test Set Sample Size: Not specified for any of the performance tests (e.g., how many stents were tested for flow rate or tensile strength). For the in vitro salt accumulation study, the "sample size" of stents tested is not provided, only that it was a "statistically significant" finding.
- Data Provenance: Not applicable in the context of patient data for an AI/algorithm. All studies appear to be bench (laboratory) tests performed by Boston Scientific or third parties.
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Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- Not applicable. This is for a physical medical device. Ground truth for most tests (e.g., tensile strength, flow rate) is established by physical measurement standards, not expert consensus interpretation of images or clinical data.
- For the in vitro salt accumulation study, ground truth would be based on lab measurements of salt deposits, not expert readings.
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Adjudication method for the test set:
- Not applicable. This is not an AI/imaging interpretation study. Adjudication methods like 2+1 or 3+1 are used for expert consensus on clinical diagnoses/interpretations, not for physical device testing.
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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, this was not done. MRMC studies are specific to evaluating AI in diagnostic imaging (human-in-the-loop performance). This document is for a physical ureteral stent.
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If a standalone (i.e. algorithm only without human-in-the-loop performance) was done:
- No, this was not done. This is not an algorithm.
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The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- For the physical/mechanical performance tests, the "ground truth" is based on engineering measurements and material science standards.
- For the biocompatibility tests, it's based on established ISO/USP standards for biological reactivity.
- For the in vitro salt accumulation study, the "ground truth" refers to laboratory measurements of calcium and magnesium salt deposition. No human expert or pathology report is involved in establishing this ground truth.
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The sample size for the training set:
- Not applicable. This document is not describing an AI/machine learning model, so there is no training set in that context. Device design and manufacturing process optimization would be an analogous "training" phase but without a formal "training set" of data points in the AI sense.
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How the ground truth for the training set was established:
- Not applicable for the same reason as #8.
Key takeaway concerning the in vitro claim:
The document explicitly states: "In vitro testing conducted on the Tria™ Firm Ureteral Stent showed a statistically significant lower level of urine calcium and magnesium salt accumulation on the stent surface compared to competitive devices. Correlation of in vitro data to clinical outcomes have not been established." This is a critical disclaimer, indicating that while the lab test showed a positive result, it has not been proven to translate to better patient outcomes in terms of reduced encrustation or longer stent patency in actual human use.
§ 876.4620 Ureteral stent.
(a)
Identification. A ureteral stent is a tube-like implanted device that is inserted into the ureter to provide ureteral rigidity and allow the passage of urine. The device may have finger-like protrusions or hooked ends to keep the tube in place. It is used in the treatment of ureteral injuries and ureteral obstruction.(b)
Classification. Class II (performance standards).