Indications, safety and warnings (2023)

Indications, safety and warnings

It is important that healthcare professionals are familiar with all indications, warnings and precautions for this device.

PS Medical Strata valves, small and regular


layers II®™ is a shunt device designed to provide continuous flow of cerebrospinal fluid (CSF) from the ventricles of the brain into the right atrium of the heart or peritoneal cavity. The Strata II valve allows the clinician to non-invasively adjust pre- and post-implant pressure/flow performance levels without the need for X-ray confirmation to meet changing patient needs.


Bypassing CSF into the peritoneal cavity or other areas of the body should not be performed if there is infection in the areas where the various components of the shunt system will be implanted. These include infections of the scalp and other areas of the skin through which the shunt system passes, cerebral meninges and ventricles, peritoneum and intraperitoneal and retroperitoneal organs, pleura, and bloodstream. CSF diversion is contraindicated when there is infection in any area of ​​the body. Furthermore, shunting to the atrium is contraindicated in patients with congenital heart disease or other severe cardiopulmonary abnormalities.

Warnings and Precautions

The valve pressure level setting should always be checked after exposing a patient to high magnetic fields.

Devices known to contain magnets should be kept away from the immediate valve implantation site as they may affect the adjustment of the Strata valve's performance level. All magnets act on the valve in an exponentially decreasing way, the greater the distance from the valve. Medtronic recommends that all products with magnets used in everyday life be at least 2 inches from where the heart valve is implanted. Usual environmental exposure to electromagnetic radiation (radio frequency) generated by Bluetooth®, computers, security scanners, metal detectors, microwave ovens, cell phones, power lines, and transformers must not affect power level settings.

Store and airport security detectors and portable security pens do not have enough magnetic force to change the adjustable valve setting. Whole-body imaging systems used at airports are based on X-rays and do not interfere with valve timing. bluetooth®is a registered trademark of Bluetooth SIG, Inc.

Valve function and power level setting should be checked if the valve is subjected to mechanical shock or significant trauma.

Use the Medtronic 45805 Neurosurgery Adapter Kit or the 45806 StrataVarius Adapter System to change the power level of the Strata II valve.

The adjustment tool contains strong magnets. Be careful when using the device near magnetically sensitive medical implants (eg cardiac pacemakers and vagus nerve stimulators), electronic devices, data storage devices such as computer diskettes or credit cards.

The Strata II Fit Kit and StrataVarius Fit System mustNObe sterilized.

Ferromagnetic substances can affect the ability of tuning tools to change and confirm the power level setting.

See theInstructions for useaccompanies the Strata II Fitting Kit or StrataVarius Fitting System for instructions, warnings, precautions and complications.

The appropriate product and size should be selected for the patient's specific needs, based on diagnostic testing and the physician's experience. Product labeling indicates applicable product performance levels or ranges.

Lint, fingerprints, baby powder, other surface contaminants, or residue from latex gloves can cause foreign bodies or allergic reactions.

Improper use of instruments when handling or implanting shunt devices can result in cutting, nicking, or crushing components. Such damage can result in loss of shunt integrity and may require premature surgical revision of the shunt system.

Care must be taken to prevent particulate contamination from entering the shunt components during testing or pre-implant handling. Introducing contaminants can result in erratic bypass system performance. Particles entering the shunt system can lead to shunt occlusion or can also keep pressure/flow control mechanisms open, leading to excessive drainage.

When connecting the catheters to the connectors, the surrounding ligatures must be secure but not too tight so that they do not cut the silicone tube.

When guiding catheters, care must be taken to avoid unnecessary bending and abrasions along their route. Abrasion can lead to premature catheter failure (rupture). The edge of the drill or hole can be trimmed to provide a beveled notch where the ventricular catheter exits and is curved to lie adjacent to the skull.

"Small" catheters have thinner walls and lower overall resistance compared to "standard" catheters. These properties lead to a comparatively higher potential failure rate (breakage rate) and therefore a shorter life expectancy for "small" catheters. Physicians who implant "small" catheters for cosmetic reasons need to recognize the potentially higher rate of catheter revisions and weigh this against the cosmetic benefit.

Patients with hydrocephalic shunt systems should be closely monitored postoperatively for signs and symptoms suggestive of shunt dysfunction. Clinical findings may indicate shunt malfunction. Clinical findings may indicate shunt obstruction or CSF overdrainage.

Shunt blockage can occur in any component of the shunt system. The system can become occluded internally due to tissue fragments, blood clots, tumor cell aggregates, bacterial colonization, or other debris. Catheters that come into contact with internal body structures may become bent or obstructed at their tips (eg, placement of a ventricular catheter tip in the choroid plexus or the distal tip of the catheter in the greater omentum or bowel loops). Finally, shunt obstruction may occur due to the growth of an infant or child or physical activities that result in the shunt components becoming separated or a distal catheter withdrawn from its intended drainage site.

Shunt blockage can occur in any component of the shunt system. The ventricular catheter can be obstructed by particles such as blood clots or brain fragments by placing the tip of the catheter in the choroid plexus, inserting the catheter into brain tissue, or adjusting the ventricular walls in case of excessive drainage ("slit ventricles").

Cut shunt components can continue to migrate.

Bypass systems can fail due to mechanical malfunction (example: incorrect system connection), resulting in insufficient or excessive drainage.

Malfunction or obstruction of the shunt system can lead to signs and symptoms of increased intracranial pressure if hydrocephalus is not compensated. In infants, the most common symptoms are increased tension in the anterior fontanelle, obstructed scalp veins, lethargy, drowsiness and irritability, vomiting, and neck stiffness. In older children and adults, the most common symptoms are headache, vomiting, blurred vision, stiff neck, decreased level of consciousness, and various abnormal neurological findings.

Excessive drainage of CSF may predispose to the development of a subdural hematoma or hydroma or collapse of the lateral ventricular walls, resulting in ventricular catheter obstruction.

If the ventricular catheter becomes attached to the choroid plexus or adjacent brain tissue by fibrous tissue adhesions, it is recommended not to remove it by force. It is suggested that gently twisting the catheter may help loosen it. It is recommended to leave the catheter in place due to the risk of intraventricular hemorrhage that can be caused by forced removal.

Subcutaneous catheter introducers can break at welds or component mounting points or due to extreme deformation of the malleable shaft. A sudden rupture can result in tissue or organ trauma and damage to the shunt system. Instruments must be checked before use to ensure integrity and functionality. Disposable instruments should never be reused, otherwise patient and clinician injury may occur.

Coagulation around the atrial portion of a catheter can lead to embolization of the pulmonary artery tree, resulting in cor pulmonale and pulmonary hypertension.

An implanted valve may interfere with a diagnostic MRI if the area of ​​interest is close to the valve site.

Risks associated with X-ray imaging include exposure to low levels of radiation, radiation-induced damage to the skin and underlying tissues, or the possibility of developing radiation-induced cancer. Care must be taken to use the lowest radiation exposure necessary to produce the image.

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

Tests have shown that applying a water column of up to 100 cm of positive pressure or 50 cm of negative pressure to the bypass system does not affect performance.

Performance characteristics are verified for all Medtronic shunt components designed to be interchangeably coupled.

The use of components or devices from other manufacturers in connection with this device has not been verified.

MRI information


The Strata II valve is considered MRI conditional per ASTM F2503.
MRI systems up to3,0Teslait can be used any time after implantation and will not damage the Strata II valve mechanism, but may change the power level setting.
The power level setting should always be checked before and after the MRI.

The results of the tests carried out to evaluate magnetic field interactions, artifacts and heating indicated that the presence of the evaluated flaps should not represent a significant risk for a patient undergoing an MRI procedure in the following conditions:

  • Static magnetic field of 3.0 Tesla or less
  • Spatial gradient of 720 G/cm or less
  • Radio frequency (RF) fields with an average specific absorption rate (SAR) of 3 W/kg for 15 minutes.

With the GE 3.0T Excite®HD MRI system, the valve experienced a maximum temperature change of 0.4°C during a 15 minute exposure period. The table contains maximum signal gaps (artifact sizes) for standard image pulse sequences at 3.0 Tesla per ASTM F2119.

Valvepulse trainpresent airplanemaximum signal void (artifact), cm²
Layers IIT1-SEParallel35.16
T1-SEna vertical33.03
GRna vertical66,55

Biological deposits within the valve can affect adjustability and result in damage to the adjustment mechanism when exposed to a 3.0 Tesla MRI. If difficulties are encountered in setting or reading the valve setting, radiographic confirmation of the setting should be considered. The Strata II Indicator Tool or StrataVarius System display can be inverted (180 degrees opposite) for the X-ray image. In this situation, radiological imaging should be used to determine valve fit.

Strata II Customization Kit and StrataVarius Customization System
AgainNOTake fitting tools or the StrataVarius system with you to an MRI facility as magnets may pose a patient and/or user safety hazard.
Proximity to the MRI room can impede scanners due to the field strength of an MRI magnet. Get closer before trying to check a valve configuration.


Complications associated with CSF ventriculoperitoneal shunt systems can be similar to those encountered with any surgical procedure performed under local and/or general anesthesia. These include reactions to drugs and anesthetics, electrolyte imbalances and excessive blood loss, particularly in babies. A patient may rarely have a reaction due to sensitivity to the implant.

With CSF diversion procedures, the most common complications are due to obstruction of the system, as described in Warnings. Obstruction can occur in any component of the system due to blockage by brain fragments, blood clots and/or tumor cell aggregates at any point in its course. Occlusion can also occur due to separation of system components or kinks and/or kinking of the catheter. This may predispose the ventricular catheter to migrate to the lateral ventricle and the distal catheter to the peritoneum or other structure in which the catheter is implanted. As mentioned earlier, the growth of the infant or child may cause the distal catheter to be withdrawn from the atrium into the internal jugular vein or from the peritoneum into tissue levels where fluid cannot be absorbed.

There are other potentially serious complications. Local and systemic infections are not uncommon in shunt procedures. They are usually caused by organisms that inhabit the skin, mainly Staphylococcus epidermidis. Other circulating pathogens can colonize the shunt and must be removed in most patients.

In 1973 Robertson et al. summarized the reported incidences of infection in ventriculoperitoneal shunts up to that time. Ventriculoperitoneal shunt infections occurred in 5 to 10% of patients in most reports.

In 1993, Kestle et al. reported significant reductions in infection (less than 4%) with the use of antibiotics, short surgical time (surgical experience), and control of the operating environment (eg, dedicated operating room, limited staff and traffic, covered skin surfaces). The article points out that the results can be achieved without the use of antibiotics, but with strict environmental control in the perioperative period.

The use of prophylactic antibiotics in patients with a shunt is somewhat controversial, as their use may predispose to infection by more resistant organisms. Therefore, the decision on the prophylactic use of antibiotics rests with the attending physician and/or surgeon.

The shunt to the peritoneum may fail due to catheter entrapment in bowel loops or greater omentum. Bowel perforation by the peritoneal catheter with subsequent development of peritonitis has been described.

CSF overdrainage can lead to an excessive reduction in CSF pressure and predispose to the development of a subdural hematoma or hygroma and an excessive reduction in ventricular size, resulting in obstruction when the ventricular walls impinge on the catheter entry holes. In infants, this excessive reduction in pressure leads to a sharp descent of the anterior fontanel, which overlaps the cranial bones and can transform the communication into obstructive hydrocephalus.

Epilepsy has been reported to occur after ventricular shunts. This study also showed that the incidence of seizures increased with multiple catheter revisions.

Intra-abdominal complications associated with peritoneal shunting include small or large bowel perforation with resultant peritonitis, perforation of other viscera, ureteral obstruction, catheter migration to an unwanted anatomical site, and development of ascites and pseudocysts.

StrataVarius customization system


StrataVarius is intended for use by clinicians to non-invasively identify the Strata-type valve setting (performance level, PL) and display this information numerically as the PL level and equivalent pressure reading in millimeters of water (mm H2O ).

StrataVarius allows the user to non-invasively change the valve pressure setting without the need for X-ray confirmation.


The Medtronic Neurosurgery StrataVarius System is not intended to be used as a diagnostic tool, only to confirm or change a pressure level in a Strata valve.

StrataVarius should not be used on fixed pressure valves. Use only with PS Medical Strata adjustable valves.

StrataVarius must not be used in a sterile environment.

Warnings and Precautions

  • StrataVarius must only be used by qualified personnel. Before using, make sure users have enough knowledge.
  • Incorrect LP setting can result in over- or under-draining of CSF, which can lead to patient complications.
  • X-ray confirmation of the pressure setting is recommended as an alternative method to determine the PL setting of the Strata valve. Risks associated with X-ray imaging include exposure to low levels of radiation, radiation-induced damage to the skin and underlying tissues, or the possibility of developing radiation-induced cancer. Care must be taken to use the least amount of radiation exposure necessary to produce the image.
  • Do not use StrataVarius to detect or adjust valves other than PS Medical Strata valves.
  • Before use, inspect the StrataVarius system for damage.
  • Allow the StrataVarius to reach operating temperature before use (see Operating/Storage Temperatures).
  • Always make sure the correct smart card is inserted.
  • Use only 1.5 volt (AA) alkaline batteries specified in the StrataVarius.
  • Check the battery level on the LCD during use. A flashing battery icon indicates low battery (voltage);REPLACE BATTERIES.
  • If StrataVarius will not be used for 6 months or more, remove batteries before storing.
  • Batteries used in StrataVarius may present a risk of fire or chemical burns if improperly handled. Do not disassemble, heat above 100°C or incinerate. There is a risk of fire or explosion if you use any other type of battery. Dispose of batteries quickly and properly. Keep away from children.
  • Dispose of StrataVarius System batteries or other components in accordance with local environmental regulations.
  • Do not touch StrataVarius battery posts.
  • Do not use acetone as a cleaning agent as it may damage the product.
  • Do not immerse any part of the StrataVarius System.
  • Do not drop the StrataVarius or any of its components on hard surfaces, as this may cause internal damage to the device.
  • To minimize the possibility of infection, clean the StrataVarius and adjust the instrument between patients.
  • The adjustment tool contains strong magnets and may damage credit cards. Keep clear of all magnetic materials and cards, computer hard drives and other magnetic media.
  • Do not bring the StrataVarius or Adapter into a room where an MRI scanner is located.
  • The StrataVarius system contains no user serviceable components. If the system needs repair, contact your local Medtronic Neurologic Technologies sales representative or call Customer Service at 1-800-468-9710 for instructions. International customers, contact your local Medtronic Neurologic Technologies sales representative.
  • StrataVarius provides a way to non-invasively check the valve; however, the position of the valve can also be determined using an X-ray image.
  • This equipment has been tested and found to comply with the EN limits of International Standard EN/IEC 60601-1, ANSI/AAMI ES 60601-1 and CAN/CSSA C22.2 No. 60601-1-08. These limits are designed to provide reasonable protection against interference in a typical medical environment. However, there is no guarantee that interference will not occur with other devices in a particular installation or use. If this device does cause harmful interference to other devices, which can be determined by turning the instrument off and on, the user is encouraged to try to correct the interference by one or more of the following measures:
    • Reorient or relocate the device
    • Increase the distance between devices
  • The StrataVarius System does not contain latex materials.



Although no known complications have been reported, the StrataVarius system should be used at the treating physician's discretion.

Ares antibiotic-impregnated catheters

Review the indications, precautions and warningsAbout Catheters impregnated with Ares™ antibiotics.

StealthStation Navigation Systems

Review the indications, precautions and warningsInformation for StealthStation® navigation systems.

important safety instructions

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

Attention doctors!
For more information, contact Medtronic NT at 1-800-468-9710 or your Medtronic NT sales representative.

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

Top Articles
Latest Posts
Article information

Author: Lakeisha Bayer VM

Last Updated: 02/12/2023

Views: 6573

Rating: 4.9 / 5 (49 voted)

Reviews: 80% of readers found this page helpful

Author information

Name: Lakeisha Bayer VM

Birthday: 1997-10-17

Address: Suite 835 34136 Adrian Mountains, Floydton, UT 81036

Phone: +3571527672278

Job: Manufacturing Agent

Hobby: Skimboarding, Photography, Roller skating, Knife making, Paintball, Embroidery, Gunsmithing

Introduction: My name is Lakeisha Bayer VM, I am a brainy, kind, enchanting, healthy, lovely, clean, witty person who loves writing and wants to share my knowledge and understanding with you.