(13 days)
The Zilver® 581™ Biliary Stent is indicated for use in the palliation of malignant strictures (neoplasms) in the biliary tree.
The Zilver® 518™ Biliary Stent is a self-expanding, nitinol stent designed for excellent radial strength and optimal flexibility. Constructed from a series of interconnected Z-shaped segments, the configuration of the stent conforms to the shape of the biliary system and provides circumferential scaffolding throughout the stent's length. The interconnected Z-shaped segments also keep foreshortening to a minimum. The Zilver® 518™ Biliary Stent comes preloaded in a 5 French delivery system. The stent is deployed with the use of a simple hand held device. The stent is currently available in unrestrained outer diameters of 4, 5, 6, 7, 8, 9 and 10 mm in lengths of 20, 30, 40, 50 and 60 mm. The 80 mm length stent is an addition to this product line.
The provided document is a 510(k) Premarket Notification for the Cook Zilver® 518™ Biliary Stent. It describes the device, its intended use, and the tests performed to assure its reliable design and performance. However, it does not include the specific details typically found in a clinical study report or a detailed device performance report that would define and then prove acceptance criteria in the way a clinical trial or algorithm validation study would.
Instead, this document focuses on demonstrating substantial equivalence to predicate devices. The "acceptance criteria" discussed here are primarily related to general device performance characteristics and manufacturing control, rather than clinical efficacy or accuracy thresholds for an AI/algorithm.
Here's an analysis based on the information provided, tailored to the requested structure, with explicit notes about what is not present:
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Specific Criteria (Implicit/Explicit) | Reported Device Performance |
|---|---|---|
| Deployment Performance | a. Profile (of the delivery system and deployed stent) | "The Zilver® 518™ Biliary Stent was subjected to the following tests to assure reliable design and performance under the specified testing parameters. These tests were comprised of: 1. Deployment: a. Profile... The results of these tests provide reasonable assurance that the device has been designed and tested to assure conformance to the requirements for its use as a biliary stent." |
| b. Deployment Accuracy | As above. | |
| c. Stent length and Change due to Deployment (e.g., minimal foreshortening) | "The Zilver® 518™ Biliary Stent...interconnected Z-shaped segments also keep foreshortening to a minimum." (This is a design claim rather than a quantifiable test result, but implicitly a performance goal). The deployment test results "provide reasonable assurance...conformance to the requirements." | |
| d. Stent Diameter (achieving specified unrestrained outer diameters: 4, 5, 6, 7, 8, 9, 10 mm, and the new 80mm length) | "The Zilver® 518™ Biliary Stent... unrestrained outer diameters of 4, 5, 6, 7, 8, 9 and 10 mm in lengths of 20, 30, 40, 50 and 60 mm. The 80 mm length stent is an addition to this product line." The deployment test results "provide reasonable assurance...conformance to the requirements." | |
| e. Uniformity of expansion | As above. | |
| f. Stent Integrity (e.g., no breakage, proper structure post-deployment) | As above. | |
| Manufacturing/Compliance | Conformance to specified process controls and a Quality Assurance Program; similar packaging and sterilization to predicate devices. | "This device will be manufactured according to specified process controls and a Quality Assurance Program... undergo packaging similar to the predicate devices... undergo sterilization similar to the predicate devices." |
| Substantial Equivalence | Similar intended use, materials of construction, and functional characteristics to predicate devices. | "The Zilver® 518™ Biliary Stent is similar in terms of intended use, materials of construction and functional characteristics to predicate devices... Being similar with respect to indications for use, materials and physical construction to predicate devices, this device meets the requirements for section 510(k) substantial equivalence." |
| Labeling | Prominently display biliary use; include warning about unestablished vascular system safety/effectiveness. | "the indication for biliary use must be prominently displayed in all labeling... in close proximity to the trade name... and in bold print." and "The safety and effectiveness of this device for use in the vascular system have not been established [must appear] in the Warnings section." (These are conditions of market clearance, not pre-market test results.) |
| Intended Use | Palliation of malignant strictures (neoplasms) in the biliary tree. | "The Zilver® 581™ Biliary Stent is indicated for use in the palliation of malignant strictures (neoplasms) in the biliary tree." (This is the declared intended use, which the "Test Data" aims to support as safe and effective compared to predicates.) |
The "study" that proves the device meets these criteria is a series of non-clinical bench tests. The document does not describe a clinical trial, and given the 510(k) pathway, a substantial equivalence claim usually relies on comparison to existing predicate devices and extensive bench testing.
Here's the breakdown for the other points, noting where information is not available in the provided text:
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
- Sample Size: Not specified for the bench tests. It's common for stent testing to involve multiple units, but the exact number isn't provided.
- Data Provenance: Not specified, but generally, bench testing would be conducted within the manufacturer's R&D facilities or accredited testing labs, likely in the US (Cook Incorporated is based in Bloomington, IN).
- Retrospective/Prospective: Not applicable, as these are bench tests, not clinical data.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
- Not applicable. As this is bench testing of physical device characteristics (profile, deployment accuracy, integrity, etc.), "ground truth" would be established by engineering specifications, measurement equipment, and industry standards, not clinical expert consensus.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
- Not applicable. This is not a clinical study involving human interpretation.
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 physical medical stent, not an AI/software algorithm.
6. If a standalone (i.e. algorithm only without human-in-the loop performance) was done
- Not applicable. This device is a physical medical stent, not an AI/software algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
- For the bench tests, the "ground truth" would be the engineering specifications and established measurement methods for properties like stent diameter, length change, and deployment accuracy. The goal is to demonstrate that the device performs according to its design specifications. For the overall submission, the "ground truth" for its clinical utility is established by its substantial equivalence to legally marketed predicate devices with proven safety and effectiveness for the same intended use.
8. The sample size for the training set
- Not applicable. This is a physical device, not a machine learning algorithm.
9. How the ground truth for the training set was established
- Not applicable. This is a physical device, not a machine learning algorithm.
Summary of what the document focuses on:
The Zilver® 518™ Biliary Stent gained 510(k) clearance by demonstrating substantial equivalence to existing predicate devices. The "study" referenced is a series of non-clinical bench tests designed to ensure the physical device characteristics (deployment, profile, accuracy, diameter, expansion uniformity, integrity) meet internal specifications and are consistent with safe and effective performance for a biliary stent. The letter from the FDA also specifies important labeling requirements as conditions of clearance, specifically limiting the stated indication to biliary use and requiring a warning about unestablished vascular use.
§ 876.5010 Biliary catheter and accessories.
(a)
Identification. A biliary catheter and accessories is a tubular flexible device used for temporary or prolonged drainage of the biliary tract, for splinting of the bile duct during healing, or for preventing stricture of the bile duct. This generic type of device may include a bile collecting bag that is attached to the biliary catheter by a connector and fastened to the patient with a strap.(b)
Classification. Class II (special controls). The device, when it is a bile collecting bag or a surgical biliary catheter that does not include a balloon component, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 876.9.