(185 days)
The RELIEF™ Ureteral Stent is intended for temporary drainage from the ureteropelvic junction to the bladder of the ureter in a variety of benign, malignant and post-traumatic conditions of the ureter. These conditions include stones and/or stone fragments or other ureteral obstructions such as those associated with ureteral stricture, malignancy of abdominal organs, retroperitoneal trauma, or in association with Extracorporeal Shock Wave Lithotripsy (ESWL). The stent may be placed using endoscopic surgical techniques. The stent is not intended as a permanent indwelling time should not exceed thirty (30) days.
The RELIEF™ Ureteral Stents are sterile, single-use devices. The stents are available in 6Fr, with lengths of 24 cm and 26 cm. The ureteral stent is constructed of a radiopaque polymer tube with a central lumen with side holes positioned along its length to provide drainage of urine from the kidney to the bladder and includes hydrophilic coating. Along the stent are printed insertion markers throughout its length. The stent includes a radiopaque soft polymeric proximal tubular coil and body segment attached to a 4 cm tether of suture material that is placed along the ureter intramural segment, allowing natural opening, and closing of the ureteral orifice, thereby preventing vesicoureteral reflux. The tether is attached to a radiopaque distal bladder coil constructed of a monofilament (non-lumened), polymeric segment, allowing it to float in the bladder, thus precluding any tension on the tether or coil. The RELIEF™ Ureteral Stent package contents consist of: RELIEF Ureteral Stent Kit; Model: RS-002 - 6 Fr x 26cm - . RELIEF™ Ureteral Stent - Stent pusher tube with radiopaque tip - . Pigtail straightener The RELIEF™ Ureteral Stent is not intended as a permanent indwelling device and is labeled for indwell time not to exceed thirty (30) days.
Here's an analysis of the provided text regarding the acceptance criteria and study for the RELIEF™ Ureteral Stent:
The document (K232920) describes a 510(k) premarket notification for a ureteral stent, focusing on a new labeling claim of preventing vesicoureteral reflux due to its design.
1. A table of acceptance criteria and the reported device performance
The document does not explicitly state formal "acceptance criteria" for the clinical study in the form of a pre-defined performance metric that the device had to meet (e.g., "sensitivity must be > X%", "proportion of patients with no reflux must be > Y%"). Instead, it presents the results of a study designed to verify a specific design claim.
However, based on the stated purpose of the clinical data and the reported outcomes, we can infer the primary performance goal: Demonstrate that the new suture tether design does not impede the normal functioning of the urinary orifice to prevent vesicoureteral reflux.
| Acceptance Criterion (Inferred from study goal) | Reported Device Performance |
|---|---|
| Normal functioning of the urinary orifice to prevent vesicoureteral reflux is maintained. | All cystograms, pre- and post-stent implant, were graded at 'No Reflux' in all 19 patients. No adverse complications observed. |
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 for Test Set: 19 patients. The study originally enrolled 26 patients, with 7 excluded based on exclusion criteria, resulting in 19 evaluated patients.
- Data Provenance:
- Country of Origin: United States (conducted in the University Hospital Cleveland Medical Center).
- Study Type: Prospective, open-label study.
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)
The document does not specify the number of experts or their qualifications for establishing the ground truth (the 'No Reflux' grade on cystograms). It only states, "All cystograms, pre- and post-stent implant, were graded at 'No Reflux'."
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
The document does not describe any specific adjudication method for the cystogram grading. It simply states they "were graded," implying a single assessment without mentioning multiple readers or a consensus process.
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
No, an MRMC comparative effectiveness study was not done. This study is about the physical device and its physiological function, not an AI or software device.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
No, this study is about a physical medical device (a ureteral stent), not a standalone algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The ground truth for the study was established through expert assessment/grading of cystogram images. The document states that "All cystograms, pre- and post-stent implant, were graded at 'No Reflux'." This implies a clinical evaluation based on imaging.
8. The sample size for the training set
This study relates to a physical medical device. There is no mention of a "training set" in the context of an algorithm. The clinical data of 19 patients serve as the evaluation data for the new labeling claim.
9. How the ground truth for the training set was established
Not applicable, as there is no training set for an algorithm in this context.
§ 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).