StrataMR Adjustable Pressure Valve INDICATIONS, SAFETY, AND WARNINGS


Medtronic is conducting a voluntary recall of the StrataMR valve due to an issue that can occur post-implantation that can lead to the potential for under-drainage of cerebrospinal fluid. This recall only applies to StrataMR adjustable valves and shunts and does not apply to Strata™ II or Strata™ NSC products.

Under-drainage of cerebrospinal fluid may result in the following adverse health consequences: headaches, nausea, vomiting, and lethargy. If left untreated, under-drainage can potentially lead to coma and death. Patients and their caregivers should monitor the patient's condition and if they find they are experiencing any of the aforementioned symptoms, they should consult the physician who implanted the StrataMR valve.

Medtronic requests that customers cease use of all StrataMR valves and shunts that remain in inventory and return all unused units to Medtronic. If any StrataMR valves have been implanted in patients, physicians should refer to the StrataMR customer recall letter sent February 22, 2017 as well as the valve adjustment instructions in the instructions for use (IFU) for continued patient care.

Adverse reactions or quality problems experienced with the use of this product may be reported to the FDA's MedWatch Adverse Event Reporting program online, by regular mail, or by fax.

Online: Complete and submit the report
Regular Mail or Fax: Download form or call +1-800-332-1088 to request a reporting form, then complete and return to the address on the pre-addressed form, or submit by fax to +1-800-FDA-0178.

For further information or to report a problem, please contact Medtronic via phone at +1-800-335-9557 between the hours of 8am and 6pm (EST) or via e-mail at

MRI Safety Information

Non-clinical testing has demonstrated that the StrataMR™ valves and shunts are MR Conditional. A patient with this device can be safely scanned in an MR system meeting the following conditions:

  • Static magnetic field of 1.5 or 3.0 tesla
  • Maximum spatial gradient magnetic field of 1900 gauss/cm (19 T/m)
  • Maximum MR system reported, whole body averaged specific absorption rate (SAR) of 4 W/kg (First Level Controlled Operating Mode)
  • The valve setting should be verified following MRI exposure

Under the scan conditions defined above, the StrataMR valves and shunts are expected to produce a maximum temperature rise of less than 3° C after 15 minutes of continuous scanning.

In non-clinical testing, the image artifact caused by the device extends approximately 30 mm from the StrataMR valve when imaged with a gradient echo pulse sequence and a 3.0 tesla MRI system.


The Medtronic StrataMR valves and shunts are designed to provide continuous cerebrospinal fluid (CSF) flow from the ventricles of the brain into the right atrium of the heart or the peritoneal cavity. The design enables the physician to non-invasively adjust valve pressure/performance level pre- and post-implantation by using magnetic adjustment tools without the need for radiographic confirmation.


Shunting of CSF into the peritoneal cavity or other areas of the body should not be carried out if there is infection in any areas in which the various components of the shunt system will be implanted. This includes infections of the scalp and other skin areas through which the shunt system will traverse, the meninges and cerebral ventricles, the peritoneum and intraperitoneal and retroperitoneal organs, the pleura and the blood stream. CSF shunting is contraindicated if there is infection present in any area of the body. Additionally, shunting into the atrium of patients with congenital heart disease or other serious cardiopulmonary abnormalities is contraindicated.

Warnings and Precautions

The valve performance level setting should be verified following patient exposure to high magnetic fields. Devices known to contain magnets should be kept away from the immediate valve implant location, as they may have an effect on the performance level setting of the StrataMR valve. All magnets have an exponentially decreasing effect on the valve the further away they are located. Common environmental levels of electromagnetic (radio frequency) radiation generated by security scanners, metal detectors, microwave ovens, mobile telephones, high voltage lines, and transformers should not affect the performance level settings.

An incorrect performance level setting may lead to overdrainage or underdrainage of CSF, which may give rise to patient complications.

Radiographic confirmation of the pressure setting is recommended as an alternate method to determine the StrataMR valve performance level setting. Risks associated with radiographic imaging include exposure to low levels of radiation, radiation-induced injuries to the skin and underlying tissues, or the possibility of developing a radiation-induced cancer. Care should be taken to use the least amount of radiation exposure needed to produce the image.

When securing catheters to connectors, the encircling ligatures should be securely, but not too tightly fastened, to avoid cutting through the silicone tubing over time.

While manipulating the ventricular catheter at the valve inlet, ensure the distal end does not become lost within the brain tissue to avoid complications.

Valve function and performance level setting should be checked in the event that the valve is subjected to significant mechanical shock or trauma.

Implanting the valve under more than 1 cm of tissue can interfere with subsequent reading and setting of the valve performance level.

The appropriate product and size must be chosen for the specific patient’s needs, based on diagnostic tests and physician experience. Failure to do so may lead to patient complications.

Use Medtronic Neurosurgery StrataMR Adjustment Tools to change the performance level in the StrataMR valve. Refer to StrataMR Adjustment Tools insert for instructions, warnings, precautions and complications. Use of other adjustment tools may result in inaccurate readings, an inability to adjust the StrataMR valve, or may damage the valve.

The performance characteristics of this device may be altered if components or devices of other manufacturers are used in conjunction with this device.

Overdrainage of CSF may predispose development of a subdural hematoma or hydroma, or collapse of the lateral ventricular walls leading to obstruction of the ventricular catheter.

Shunt obstruction may occur in any of the components of the shunt system. The system may become occluded internally due to tissue fragments, blood clots, tumor cell aggregates, bacterial colonization, or other debris. Catheters, which contact internal body structures, can become kinked or blocked at their tips. Occluded catheters can lead to underdrainage.

Shunt disconnection may also occur due to growth of an infant or child, or physical activities, which result in disconnection of the shunt components or withdrawal of a distal catheter from its intended drainage site. Disconnection may cause complications. Disconnected shunt components may migrate.

Malfunction or obstruction of the shunt system may lead to signs and symptoms of increased intracranial pressure if the hydrocephalus is not compensated. In the infant, the common symptoms are increased tension of the anterior fontanelle, congestion of scalp veins, listlessness, drowsiness and irritability, vomiting and nuchal rigidity. In older children and adults, the common symptoms are headaches, vomiting, blurring of vision, nuchal rigidity, deterioration of consciousness, and various abnormal neurological findings.

Patients with CSF shunt systems must be kept under close observation in the postoperative period for signs and symptoms that suggest shunt malfunction. The clinical findings may indicate shunt infection or other complications such as CSF leaks due to the puncture of the dura, shunt obstruction, underdrainage or overdrainage of CSF.

Shunt systems may fail due to mechanical malfunction leading to underdrainage or overdrainage.

Improper use of instruments in the handling or implantation of shunt products may result in the cutting, slitting or crushing of components. Such damage may lead to loss of shunt integrity and necessitate premature surgical revision of the shunt system.

Care must be taken to ensure that particulate or other contaminants (such as latex) are not introduced into shunt components during preimplantation testing or handling. Introduction of contaminants could result in improper performance of the shunt system, foreign body reactions, or allergic reactions. Particulate matter that enters the shunt system may result in shunt occlusion, or may also hold pressure/flow controlling mechanisms open, resulting in overdrainage.


MRI Safety Information

The StrataMR Adjustment Tools are MR unsafe. Do NOT take the Adjustment Tools or the case into an MRI facility as these magnets could potentially be a safety hazard to the patient and/or user.

The valve performance level setting should be verified following MRI exposure.

Proximity to an MRI suite may impede the mechanism in the Indicator Tool due to the field strength of an MRI magnet. Valve settings must be verified outside of the MR environment.

Warnings and Precautions

The StrataMR is for use by qualified personnel only; ensure users have adequate knowledge to prevent misuse.

Prior to each use, inspect the Adjustment Tools for signs of damage. Signs of damage include, but are not limited to: cracking of plastic parts, or leakage of compass damping oil. The device should not be used if any such signs of damage are identified.

Do not use the components of the StrataMR Adjustment Tools (Locator Tool, Indicator Tool, and Adjustment Tool) to read or adjust any valves other than StrataMR valves. The components will not work accurately.

To avoid injury or damage, the Adjustment Tool should be stored in the magnetically shielded case before and immediately after use. The Adjustment Tool can strongly and uncontrollably accelerate toward other magnets or ferrous materials. Do not open more than one tool case at a time. The force of the powerful magnet can damage items and cause injury to the patient and/or user.

The Adjustment Tool contains strong magnets. Care should be taken when using the tool near magnetically sensitive medical implants (for example, pacemakers and vagal nerve stimulators), electronic equipment, and data storage devices such as computer diskettes or credit cards.

Do NOT take the Adjustment Tools or the case into an MRI facility as these magnets could potentially be a safety hazard to the patient and/or user.

Ferromagnetic substances may impede the ability of the Adjustment Tools to change and confirm the performance level setting.

Do not burn or incinerate the Adjustment Tools or the case because toxic fumes can be created.

Do not use the Adjustment Tool in an explosive atmosphere because uncontrolled acceleration of the tool may induce a spark.

Do not attempt to open the Adjustment Tool's magnetic assemblies because it could lead to user injury or a broken device.

Ensure that the Locator Tool is properly centered over and aligned to the magnetic valve mechanism. Failure to accurately position the Locator Tool could result in an incorrect reading of the performance level setting which may lead to over or under drainage of CSF causing patient complications.

Maintain alignment of the Adjustment Tool with the current valve setting when the distance between the tool and the valve is less than 15 cm (6"), or an inadvertent change in performance level setting could occur. Always use the Indicator Tool to confirm desired performance level setting after using the Adjustment Tool.

The StrataMR valve is designed with five wells separated by raised walls. The valve mechanism must be seated within the wells to achieve the intended pressure flow performance otherwise under drainage may occur and result in patient complications. It is recommended that the initial performance level of the implanted StrataMR valve be changed no more than one performance level in any 24-hour period. Throughout this post adjustment period, the clinical condition of the patient should be carefully monitored.

Excessive swelling or bandages may make it difficult to determine a valve setting. Wait until swelling is reduced, or confirm with radiographic imaging. In addition, scalp and overlying tissue thickness can make it difficult to determine the valve setting. If this is the case, confirm the valve setting with radiographic imaging.

An incorrect PL setting may lead to over or under drainage of CSF, which may give rise to patient complications.

Radiographic confirmation of the pressure setting is recommended as an alternate method to determine the Strata valve PL setting. Risks associated with radiographic imaging include exposure to low levels of radiation, radiation-induced injuries to the skin and underlying tissues, or the possibility of developing a radiation-induced cancer. Care should be taken to use the least amount of radiation exposure needed to produce the image.

The StrataMR Adjustment Tools can be cleaned with warm water and mild detergent. Avoid the use of aggressive solvents, bleaches, or sterilization procedures to prevent tool damage.