Maladjustment of programmable ventricular shunt valves by inadvertent exposure to a common hospital device

Abstract

Background:Programmable ventricular shunt valves are commonly used to treat hydrocephalus. They can be adjusted to allow for varying amounts of cerebrospinal fluid (CSF) flow using an external magnetic programming device, and are susceptible to maladjustment from inadvertent exposure to magnetic fields.Case Description:We describe the case of a 3-month-old girl treated for hydrocephalus with a programmable StrataTM II valve found at the incorrect setting on multiple occasions during her hospitalization despite frequent reprogramming and surveillance. We found that the Vocera badge, a common hands-free wireless communication system worn by our nursing staff, had a strong enough magnetic field to unintentionally change the shunt setting. The device is worn on the chest bringing it into close proximity to the shunt valve when care providers hold the baby, resulting in the maladjustment.Conclusion:Some commonly used medical devices have a magnetic field strong enough to alter programmable shunt valve settings. Here, we report that the magnetic field from the Vocera hands-free wireless communication system, combined with the worn position, results in shunt maladjustment for the StrataTM II valve. Healthcare facilities using the Vocera badges need to put protocols in place and properly educate staff members to ensure the safety of patients with StrataTM II valves.

Evaluation of smartphone-integrated magnetometers in detection of safe electromagnetic devices for use near programmable shunt valves: a proof-of-concept study

“…We advocate for structured shunt education 30 and have integrated patient/family usage of the patient-centric free Hydrocephalus Association HydroAssist smartphone app 31 into our own practice. Our group supports the guidelines recently published by the FDA, 12 which recommend keeping products that contain magnets 2 or more inches away from the location of a programmable CSF shunt valve. Patients continue to be advised to use the ear opposite the shunt valve for devices that require listening, such as cellular phones and earbuds.…”

“…Although devices from the most recently developed generation have been designed with greatly improved resistance to MFs, [4][5][6][7][8] devices sensitive to field strengths of more than 90 Gauss (G) are still commonly implanted and will exist in patients for decades to come. A wide variety of medical 9,10 and consumer 8,[11][12][13][14][15][16][17] devices with MFs have been reported to interfere with the PV mechanism and setting in vitro and in vivo (Fig. 1).…”

Approach to Cochlear Implantation in Patients With Ventriculoperitoneal Shunts

“…In such cases, preoperative shunt settings should be documented, and early postoperative follow‐up with a neurologist or neurosurgeon to document shunt functionality and settings is advisable. Depending on the specific shunt system, published data shows that a magnet strength of 80 to 90 Gauss is sufficient to alter shunt settings 10‐13 . Prior publications examining earlier generation devices and unpublished data from each manufacturer on current technology show that magnet strength is typically below this threshold at a distance of 1.5 to 2 cm, with slight variation noted (Advanced Bionics Research and Development, e‐mail communication, August 2022; MED‐EL Research and Development, e‐mail communication, August 2022; Cochlear Limited Surgical and Implant Product Management, e‐mail communication, October 2022) 7,8 .…”

“…Depending on the specific shunt system, published data shows that a magnet strength of 80 to 90 Gauss is sufficient to alter shunt settings. [10][11][12][13] Prior publications examining earlier generation devices and unpublished data from each manufacturer on current technology show that magnet strength is typically below this threshold at a distance of 1.5 to 2 cm, with slight variation noted (Advanced Bionics Research and Development, e-mail communication, August 2022; MED-EL Research and Development, e-mail communication, August 2022; Cochlear Limited Surgical and Implant Product Management, e-mail communication, October 2022). 7,8 Given this, a distance of at least 2 cm between magnetic components is recommended to mitigate this risk in all current devices.…”

Erratum: Maladjustment of programmable ventricular shunt valves by inadvertent exposure to a common hospital device

“…In the article titled “Maladjustment of programmable ventricular shunt valves by inadvertent exposure to a common hospital device”, published on pages 51, Issue 1, Volume 9 of Surgical Neurology International,[ 1 ] the wrong sentence was published as “Finally, the Polaris Sophysa valve, requiring the strongest magnetic force, was altered at 170 G when placed directly against the device. [14] ” instead of “ The Sophysa Polaris valve was not altered by a magnet at any distance, due to its unique architecture designed to resist maladjustment by requiring simultaneous unlocking movement, in opposite directions, of two internal micromagnets.”…”