(167 days)
The Magnetic Surgical System is designed to grasp and retract the body and the fundus of the gallbladder in laparoscopic cholecystectomy procedures and the liver in bariatric procedures to facilitate access and visualization of the surgical site. The device is indicated for use in patients with a BMI range of 20-60 kg/m².
The Levita Magnetic Surgical System is composed of two hand-held instruments, the Magnetic Grasper Device and external Magnetic Controller. The Magnetic Grasper Device (sterile, single use), comprised of a distal Detachable Grasper attached to a Delivery/Retrieval shaft with Handle, is actuated via its pistol-grip Handle with two distinct scissor-type motions to open and close the Detachable Grasper jaws. Once the Magnetic Grasper Device is inserted through a compatible ≥ 10 mm laparoscopic port and the Detachable Grasper is attached to the desired tissue, the Detachable Grasper can be detached from the Delivery/Retrieval Shaft and controlled externally using the Magnetic Controller. Traction of the tissue is maintained through the magnetic field attraction between the Detachable Grasper and the Magnetic Controller. The Magnetic Controller (non-sterile, reusable) is a single unit with handles that is held external to the body and emits a magnetic field that attracts the Detachable Grasper. Once the Detachable Grasper is attached to the desired tissue and detached from the Delivery/Retrieval Shaft, the Magnetic Controller is placed external to the body to magnetically attract the Detachable Grasper to manipulate the target tissue. Adjusting the distance between the Magnetic Controller and the Detachable Grasper will modulate the magnetic attraction used for tissue retraction/mobilization. If desired, the user can connect the Magnetic Controller to a commercially available surgical support arm that is compatible with its arm mount.
This document is a 510(k) summary for the Levita Magnetic Surgical System, focusing on a modification to its Indications for Use. The core of the submission demonstrates that the modified device remains substantially equivalent to its predicate.
Here's an analysis of the provided information regarding acceptance criteria and the supporting study:
1. Table of Acceptance Criteria and Reported Device Performance
The acceptance criteria are implicitly defined by the "Special Controls" for the Magnetic Surgical System (21 CFR 878.4815), which mandate specific performance data. The device performance is then reported against these special controls.
| Acceptance Criterion (Special Control) | Reported Device Performance |
|---|---|
| (1) In vivo performance data must demonstrate that the device performs as intended under anticipated conditions of use. Testing must demonstrate the ability of the device to grasp, hold, retract, mobilize or manipulate soft tissue and organs. | Met: Clinical performance data from two separate studies totaling 103 subjects (73 retrospective, 30 prospective) demonstrated successful use for liver retraction in all cases. |
- No severe or serious adverse events related to the device.
- No device failure or malfunctions.
- Adequately grasped and retracted the liver for effective exposure.
- Not necessary to use another instrument for retraction.
- Overall procedure times similar to published averages.
- All cases performed with a reduced port technique, avoiding an incision for a liver retractor. |
| (2) Non-clinical performance data must demonstrate that the system performs as intended under anticipated conditions of use, specifically: (a) Magnetic field strength characterization and (b) Ability of internal surgical instrument(s) to couple, de-couple, and re-couple. | Met: No technological changes to the device that would affect magnetic field strength or coupling. Previously conducted non-clinical performance testing applies. |
| (3) Patient-contacting components must be demonstrated to be biocompatible. | Met: No changes to the device's patient-contacting components. Previously conducted biocompatibility testing applies. |
| (4) Performance data must demonstrate the sterility of patient-contacting device components. | Met: No changes to the device that would affect sterility. Previously conducted sterility testing applies. |
| (5) Methods and instructions for reprocessing reusable components must be validated. | Met: No changes to the device that would affect reprocessing. Previously conducted validation of reprocessing methods and instructions applies. |
| (6) Performance data must support shelf life by demonstrating continued sterility and functionality. | Met: No changes to the device that would affect shelf life. Previously conducted shelf life testing applies. |
| (7) Training must be developed and validated by human factors testing and analysis to ensure users can follow instructions for safe use. | Met: The training program was updated for the revised Indications for Use (liver retraction in bariatric patients with higher BMI). A new human factors validation was deemed unnecessary because: 1) device design is unchanged, 2) no new use problems identified, 3) use-related hazards and mitigations are unchanged, and 4) critical tasks and errors remain the same. This was supported by clinical performance data from the two studies where investigators had used the updated training program, and the studies met safety and effectiveness endpoints. Previously conducted human factors testing applies. |
| (8) Labeling Requirements (Magnetic field safezones, Instructions for proper use, Screening checklist, Reprocessing instructions, Shelf life, Use life). | Met: The labeling complies with the stated special controls. |
2. Sample Sizes Used for the Test Set and Data Provenance
- Total Test Set Sample Size: 103 subjects
- Retrospective Study: 73 subjects
- Country of Origin: Not explicitly stated, but the study was conducted at "Duke Center for Metabolic and Weight Loss Surgery" in the US.
- Data Provenance: Retrospective (patients between October 2016 and August 2017).
- Prospective Study: 30 subjects
- Country of Origin: Santiago, Chile (Hospital La Florida).
- Data Provenance: Prospective, single-arm, open-label study.
- Retrospective Study: 73 subjects
3. Number of Experts Used to Establish Ground Truth for the Test Set and Qualifications
The ground truth in this context is the successful clinical outcome and safe use of the device in surgical procedures. This was directly observed and reported by operating surgeons.
- Retrospective Study: 10 participating surgeons. No specific qualifications beyond "surgeon" are provided.
- Prospective Study: 3 participating surgeons. No specific qualifications beyond "surgeon" are provided.
4. Adjudication Method for the Test Set
The document does not describe an explicit adjudication method for the test set in the traditional sense of multiple independent readers evaluating images or data points and then adjudicating discrepancies. The "ground truth" was established by the performing surgeons themselves, who assessed the device's ability to adequately grasp and retract tissue and reported on safety outcomes (adverse events, device failures). Clinical outcome was the primary measure, not subjective reader interpretations.
5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and Effect Size
No, a multi-reader multi-case (MRMC) comparative effectiveness study was not conducted. The study evaluated the device's safety and effectiveness in a clinical setting, not how human readers' diagnostic performance might improve with or without AI assistance. This device is a surgical instrument, not an AI diagnostic tool.
6. If a Standalone (i.e., algorithm only without human-in-the-loop performance) Was Done
This question is not applicable. The Levita Magnetic Surgical System is a physical surgical instrument, not a software algorithm or AI. Its performance is intrinsically linked to its use by a human surgeon. The "standalone" concept applies to AI algorithms that can process data and make inferences without direct human intervention in the interpretation phase.
7. The Type of Ground Truth Used
The ground truth used was clinical outcome data and observed intraoperative performance, as documented by treating physicians (surgeons). This included:
- Successful completion of the bariatric surgery using the device.
- Adequate liver retraction and visualization of the surgical site.
- Absence of the need to use another instrument for liver retraction.
- Occurrence and type of adverse events (e.g., petechiae, liver capsule abrasions) and their resolution.
- Device failure or malfunctions.
- Procedure times.
8. The Sample Size for the Training Set
No "training set" in the context of machine learning is mentioned or applicable here. This device is a physical medical instrument, not an AI/ML algorithm that requires a data training set. The clinical studies represent performance validation, not data input for model training.
9. How the Ground Truth for the Training Set Was Established
This question is not applicable, as there was no AI/ML training set.
§ 878.4815 Magnetic surgical instrument system.
(a)
Identification. A magnetic surgical instrument system is a prescription device used in laparoscopic surgical procedures consisting of several components, such as surgical instruments, and a magnetic controller. The magnetic controller is provided separately from the surgical instrument and is used outside the patient. The external magnetic controller is magnetically coupled with the internal surgical instrument(s) at the surgical site to grasp, hold, retract, mobilize, or manipulate soft tissue and organs.(b)
Classification. Class II (special controls). The special controls for this device are:(1) In vivo performance data must demonstrate that the device performs as intended under anticipated conditions of use. Testing must demonstrate the ability of the device to grasp, hold, retract, mobilize, or manipulate soft tissue and organs.
(2) Non-clinical performance data must demonstrate that the system performs as intended under anticipated conditions of use. The following performance characteristics must be tested:
(i) Magnetic field strength testing characterization to identify the distances from the magnet that are safe for patients and users with ferromagnetic implants, devices, or objects.
(ii) Ability of the internal surgical instrument(s) to be coupled, de-coupled, and re-coupled with the external magnet over the external magnet use life.
(3) The patient-contacting components of the device must be demonstrated to be biocompatible.
(4) Performance data must demonstrate the sterility of the device components that are patient-contacting.
(5) Methods and instructions for reprocessing reusable components must be validated.
(6) Performance data must support shelf life by demonstrating continued sterility of the device or the sterile components and device functionality over the labeled shelf life.
(7) Training must be developed and validated by human factors testing and analysis to ensure users can follow the instructions for use to allow safe use of the device.
(8) Labeling must include:
(i) Magnetic field safe zones.
(ii) Instructions for proper device use.
(iii) A screening checklist to ensure that all patients and operating staff are screened from bringing ferromagnetic implants, devices, or objects near the external magnet.
(iv) Reprocessing instructions for any reusable components.
(v) Shelf life.
(vi) Use life.