(90 days)
The Strata NSC Lumboperitoneal Shunt System provides continued cerebrospinal fluid (CSF) flow from the subarachnoid space into the peritoneal cavity. The Strata NSC Lumboperitoneal Valve allows the physician to non-invasively adjust the pressure/flow performance level pre- and post-implantation in order to address changing patient needs. The Strata NSC Lumboperitoneal Shunt System is designed for management of communicating hydrocephalus and may be used in the treatment of idiopathic intracranial hypertension (pseudotumor cerebri) when shunting is an option.
The Strata NSC Lumboperitoneal Valve and Shunt Systems are comprised of lumbar and peritoneal catheters, valves and accessories. The lumboperitoneal valve allows the physician to noninvasively adjust the pressure/flow performance level pre- and post-implantation using magnetic adjustment tools in order to address changing patient needs. The lumbar catheters are available in closed-tip and open-tip configurations and have length markers located at 5 cm intervals. A strain relief provides support to and lessens the potential of catheter kinking at the junction of the lumbar catheter to the valve and fixation tabs are provided to anchor catheters at the incisions.
Section {0} indicates that this 510(k) submission is for an expanded indication for the Medtronic Strata NSC Lumboperitoneal Valve and Shunt System to include the treatment of idiopathic intracranial hypertension (pseudotumor cerebri). The acceptance criteria and performance data described below relate to demonstrating that the device maintains its safety and effectiveness for this new indication.
1. Acceptance Criteria and Reported Device Performance
The provided text {1} states that "retrospective clinical review of data which includes prospective follow-ups is provided to demonstrate that physicians are able to palpate the valve, determine the direction of flow and to accurately read the pressure level setting using the StrataVarius device consistently with radiographic imaging verification when these shunt systems are used for lumboperitoneal applications."
Based on this, the implicit acceptance criteria relate to the consistency and accuracy of clinical assessment (palpation, flow direction, pressure level reading) of the device when compared to radiographic imaging verification. While specific metrics (e.g., percentage agreement, sensitivity/specificity) are not explicitly stated, the FDA's acceptance of the submission implies that the reported performance met their requirements for demonstrating substantial equivalence for the expanded indication.
| Acceptance Criteria (Implicit) | Reported Device Performance (Summary) |
|---|---|
| Physicians are able to palpate the valve consistently. | Demonstrated that physicians are able to palpate the valve. |
| Physicians are able to determine the direction of flow consistently. | Demonstrated that physicians are able to determine the direction of flow. |
| Physicians are able to accurately read the pressure level setting using the StrataVarius device consistently with radiographic imaging verification. | Demonstrated that physicians are able to accurately read the pressure level setting using the StrataVarius device consistently with radiographic imaging verification. |
2. Sample Size Used for the Test Set and Data Provenance
The text mentions "a retrospective clinical review of data which includes prospective follow ups." However, the exact sample size used for this clinical review (test set) is not specified in the provided document.
Regarding data provenance, the study is a "retrospective clinical review... which includes prospective follow ups." This suggests a combination of retrospective data (likely patient records from previous implantations) and prospective data (follow-up observations on a subset of these or newly enrolled patients). The country of origin of the data is not specified.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts
The document does not specify the number of experts used or their qualifications for establishing the ground truth. The ground truth itself is stated as "radiographic imaging verification." This implies that the standard for comparison was consensus or interpretation of these images by presumably qualified medical professionals.
4. Adjudication Method for the Test Set
The document does not specify any explicit adjudication method (e.g., 2+1, 3+1). The ground truth is described as "radiographic imaging verification," suggesting that the radiographic findings served as the definitive reference.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve with AI vs. Without AI Assistance
This section describes a medical device (a shunt system and valve for CSF management), not an AI-powered diagnostic or assistive tool. Therefore, an MRMC comparative effectiveness study involving AI assistance was not performed and is not applicable in this context. The study focuses on the physicians' ability to clinically assess the device against radiographic verification, not on improvement with AI.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
This is a medical device, not an algorithm. Therefore, a standalone algorithm performance study was not done and is not applicable. The performance data relates to the device's functionality (readability, adjustability, non-migration) and the ability of physicians to interact with it.
7. The Type of Ground Truth Used
The ground truth used for the clinical review was radiographic imaging verification. This implies that imaging studies (e.g., X-rays, CT scans) were used to objectively confirm the valve's setting, flow direction, or position, against which the physicians' clinical assessments were compared.
8. The Sample Size for the Training Set
The document does not specify a separate "training set" or its sample size. The clinical review described is a performance evaluation, not a machine learning model development, so the concept of a training set as typically understood in AI is not directly applicable. The "retrospective clinical review" itself served as the evidence base.
9. How the Ground Truth for the Training Set Was Established
Since there is no explicit "training set" as understood in machine learning contexts, the question of how its ground truth was established is not applicable. The evidence provided is for the device's clinical performance, with radiographic imaging serving as the objective standard for validation.
§ 882.5550 Central nervous system fluid shunt and components.
(a)
Identification. A central nervous system fluid shunt is a device or combination of devices used to divert fluid from the brain or other part of the central nervous system to an internal delivery site or an external receptacle for the purpose of relieving elevated intracranial pressure or fluid volume (e.g., due to hydrocephalus). Components of a central nervous system shunt include catheters, valved catheters, valves, connectors, and other accessory components intended to facilitate use of the shunt or evaluation of a patient with a shunt.(b)
Classification. Class II (performance standards).