Indications, Safety, and Warnings StrataMR II adjustable pressure valve

Intended purpose/Indications for use

The StrataMR™ ll 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

  • Testing shows that the valve mechanism is resistant to unintended changes in Performance Level setting in a 3 Tesla MRI. However, the valve performance level setting should be verified following a magnetic resonance imaging (MRI) procedure. A change in the Performance Level setting is unlikely under normal circumstances, however, devices known to contain magnets should not be placed in close proximity to the valve implant location, as they may have an effect on the performance level setting of the StrataMR II 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.
  • Walk-through security detectors in stores and airports, as well as hand-held security wands, do not have enough magnetic strength to change the setting of the adjustable valve. The full body imaging systems used at airports are x-ray based and will not interfere with the valve setting. Bluetooth is a registered trademark of Bluetooth SIG, Inc.
  • An incorrect performance level setting may lead to over-drainage or under-drainage of CSF which may give rise to patient complications.
  • An implanted valve may interfere with a diagnostic MRI if the area in question is near the location of the valve.
  • Radiographic confirmation of the pressure setting is recommended as an alternate method to determine the StrataMR ll 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 the StrataMR adjustment tools to change the performance level in the StrataMR ll 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 ll 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.
  • Testing shows that applying a water column of up to 100cm positive pressure or 50cm negative pressure to the shunt system does not impair performance.
  • The use of components or devices of other manufactures in conjunction with this device has not been verified.
  • 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 that contact internal body structures can become kinked or blocked at their tips. Occluded catheters can lead to under-drainage.
  • Shunt disconnection may also occur due to growth of an infant or child, or physical activities that 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, under-drainage or over-drainage of CSF.
  • Shunt systems may fail due to mechanical malfunction (example: improper connection of system) leading to under-drainage or over-drainage.
  • 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 hold pressure/flow controlling mechanisms open, resulting in over-drainage.
  • This device is supplied STERILE for single use only. Do not reprocess or re-sterilize.
  • Visually inspect all sterile barrier systems, that are labeled as sterile, immediately prior to use. Do not use the device if breaches in sterile barrier system integrity are evident.
  • This device is non-pyrogenic.

Important safety information

Attention Consumers!
This therapy is not for everyone. Please consult your physician. A prescription is required. For more information, please contact us at 1-800-468-9710.

Attention Physicians!
For further information, please call Medtronic NT at 1-800-468-9710, or contact your Medtronic NT sales representative.

Caution: Federal (USA) law restricts this device to sale by or on the order of a physician. Refer to product package insert for instructions, warnings, precautions and complications. 

Visit the Medtronic Manual Library to view full Instructions for Use.