(29 days)
The Roth Net® retriever product line is intended to be used to retrieve excised polyps, tissue samples, foreign bodies and calculi during flexible and rigid endoscopy procedures.
The Roth Net retriever product line is intended to be used to retrieve excised polyps, tissue samples, foreign bodies and calculi during flexible and rigid endoscopy procedures. The device is marketed in both sterile and non-sterile versions. The fundamental design and technology of the Roth Net® retriever are the same as the predicate Polyp Snare Net originally submitted under K926104 with the exception of the changes listed below. The device consists of a proximal handle with a finger ring that controls the deployment of the fabric mesh basket (a wire snare with a fabric net attached). The snare/net is connected to a drive wire, which is then connected to the handle. The drive wire is encompassed within a sheath that makes up the catheter.
The Roth Net® retriever product line, subject of K122462, is intended for retrieving excised polyps, tissue samples, foreign bodies, and calculi during flexible and rigid endoscopy procedures. The submission details several modifications from the predicate device (Polyp Snare Net, K926104). The studies conducted focus on verifying that these modifications do not adversely affect the device's performance, safety, or effectiveness, and that the device remains substantially equivalent to its predicate.
1. Table of Acceptance Criteria and Reported Device Performance
| Device Modification | Reason for Modification | Acceptance Criteria | Verification Results |
|---|---|---|---|
| Changes for Clinical Ease of Use | |||
| Change in snare shape (round to octagonal) and snare loop wire shape (braided to flat) | To better allow the loop to maintain its shape and allow for greater capacity. | 1. Force required to deploy and retract shall be ≤ 3.25 lbs. |
- Net can be fully retracted without any parts left outside of the sheath.
- Net can be fully deployed without exposing the proximal end of the connector. | PASS |
| Change in the mesh size of the net | To improve visibility when capturing multiple polyp fragments. | 1. Must maintain ability to grasp and retrieve simulated polyps and foreign bodies. - Net is capable of securing material that measures 2cm x 1.5cm x 2.5cm.
- Visualization of pouch and its contents are not obstructed. | PASS |
| Dimensional Changes: Increased length and diameter of device sheath/catheter | Allow use of subject-device with various endoscopes. | 1. Length shall be 138.00 ± 2.5 inches (350.5 ± 6.35 cm). - Visible plastic deformation due to compression must not occur in an insertion column length of 1.5 in (3.8 cm) through the accessory channel of the endoscope.
- Device shall capture simulated food bolus, foreign bodies or polyps while maintaining structural integrity.
- Insertion force of less than or equal to 2.5 lbs. | PASS |
| Dimensional Changes: Net size changed to largest size: 3 cm (l) x 4 cm (w) | To allow device to be used with endoscopes with larger channels. | 1. Max deployment/retraction force shall be ≤ 3.25 lbs. - The length of the fully deployed net shall be 2.59 - 3.29 inches (6.6 – 8.4 cm).
- The width of the fully deployed net shall be 1.41 – 2.10 inches (3.6 – 5.3 cm). | PASS |
| Changes for Increased Manufacturing Efficiency | | | |
| A chamfer melt was added on the inside of the catheter | To maintain the smooth transition of the snare/net into the catheter when the snare/net is retracted. | Max deployment force shall be ≤ 3.25 lbs.
Max retraction force shall be ≤ 3.25 lbs. | PASS |
| Change in the mesh configuration to add bidirectional mesh | Increased manufacturability. | 1. Grasp the objects and held securely in the net. - Beads are captured and controlled. | PASS |
| Change in the length of the wire loop ends of the snare loop assembly and flat wire | To facilitate the change from a crimp to a resistance welding connection. | Tensile pull must be ≥ 12 lbs (Test connection between drive cable to wire form of the snare loop). | PASS |
| Addition of a mesh net tail on the distal and proximal sides of the net | Eliminate the need for thread as an anchor to prevent net cinching. | 1. Nets shall not cinch. - Proximal and distal anchors shall remain intact. | PASS |
| Material Change | | | |
| Catheter material modified from TFE to PE | Cost Reduction without reducing performance. | Material shall show no reactivity in test subjects. | PASS |
| Appearance Change | | | |
| Change handle color from white to silver | Add new color to distinguish between standard and platinum models. | No risks were identified in relation to this modification. No performance data were required because a change in color of the handle does not affect performance of the subject device. | |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample sizes for each specific test, nor does it detail the provenance of the data (e.g., country of origin, retrospective/prospective). However, for the tensile strength testing, it is mentioned that the "Test connection between drive cable to wire form of the snare loop" was performed on 30 devices. For other functional tests, terms like "simulated polyps and foreign bodies," "variety of items," and "test subjects" are used, implying in-vitro or bench testing rather than human clinical data. The studies are described as "verification and validation testing" and "design verification tests," which are typically internal development and testing activities.
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The document does not mention the use of experts to establish a "ground truth" for the test set in the context of clinical interpretation or diagnosis. The testing performed is focused on the physical and functional performance of the device's modifications against engineering specifications and simulated use scenarios. Therefore, the concept of qualified experts establishing a ground truth in an interpretive sense (like radiologists for imaging) is not applicable here. The "ground truth" for these tests would be the established engineering specifications and successful completion of the functional tasks.
4. Adjudication Method for the Test Set
No adjudication method (e.g., 2+1, 3+1) is mentioned or appears applicable, as the tests described are objective measurements of physical performance and functional capabilities against predefined specifications (e.g., force measurements, dimensions, grasping ability). These are not subjective interpretations requiring adjudicators.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No MRMC comparative effectiveness study was conducted or mentioned. This type of study (comparing human readers with and without AI assistance) is not relevant for a physical medical device like the Roth Net® retriever, which is a tool for retrieval during endoscopy, not an AI-powered diagnostic device.
6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Study Was Done
This question is not applicable. The Roth Net® retriever is a physical medical device that is used by a human during an endoscopy procedure; it does not involve any algorithms or standalone AI performance.
7. The Type of Ground Truth Used
The "ground truth" used for these studies is based on:
- Engineering Specifications: Predefined numerical values for dimensions, forces, and material properties.
- Functional Performance Criteria: The ability of the device to successfully perform its intended functions in simulated environments (e.g., grasp simulated polyps, retract fully, maintain structural integrity).
- Biocompatibility Standards: Compliance with ISO 10993 standards for material safety, where "no reactivity in test subjects" serves as the ground truth for biocompatibility.
8. The Sample Size for the Training Set
No training set is applicable. This device is not an AI/ML-based device that requires a training set.
9. How the Ground Truth for the Training Set Was Established
Not applicable, as there is no training set for this device.
§ 876.4300 Endoscopic electrosurgical unit and accessories.
(a)
Identification. An endoscopic electrosurgical unit and accessories is a device used to perform electrosurgical procedures through an endoscope. This generic type of device includes the electrosurgical generator, patient plate, electric biopsy forceps, electrode, flexible snare, electrosurgical alarm system, electrosurgical power supply unit, electrical clamp, self-opening rigid snare, flexible suction coagulator electrode, patient return wristlet, contact jelly, adaptor to the cord for transurethral surgical instruments, the electric cord for transurethral surgical instruments, and the transurethral desiccator.(b)
Classification. Class II (performance standards).