Programmable shunt valve interactions with osseointegrated hearing devices

Abstract

<jats:sec> <jats:title>OBJECTIVE</jats:title> <jats:p>Patients with ventriculoperitoneal (VP) shunts with programmable valves who would benefit from osseointegrated hearing devices (OIHDs) represent a unique population. The aim of this study was to evaluate the magnetic field strengths of 4 OIHDs and their interactions with 5 programmable VP shunt valves.</jats:p></jats:sec> <jats:sec> <jats:title>METHODS</jats:title> <jats:p>Magnetic field strength was measured as a function of distance for each hearing device (Cochlear Baha 5, Cochlear Baha BP110, Oticon Ponto Plus Power, and Medtronic Sophono) in the following modes: inactive, active in quiet, and active in 60 decibels of background noise in the sound booth. The hearing devices were introduced to each shunt valve (Aesculap proGAV, Aesculap proGAV 2.0, Codman Hakim, Codman Certas, and Medtronic Strata II) also as a function of distance in these identical 3 settings. Each trial was repeated 5 times. Between each trial, the valves were assessed for a change in setting. Finally, using a skull model, the devices were introduced to each other in standard anatomical locations and the valves were assessed for a change in settings.</jats:p></jats:sec> <jats:sec> <jats:title>RESULTS</jats:title> <jats:p>The maximum magnetic field strengths generated by the Cochlear Baha 5, BP110, and Oticon OIHDs were 1.1, 36.2, and 48.7 gauss (G), respectively. The maximum strength generated by the Sophono device was &gt; 800 G. The magnetic field strength of the hearing devices decreased markedly with increasing distance from the device. The strength of the Sophono's magnetic attachment decreased to 34.8 G at 5 mm. The Codman Hakim, Codman Certas, and Medtronic Strata II valve settings changed when rotating the valves next to the Sophono abutment. No other changes in valve settings occurred in the distance or anatomical models for any other trials.</jats:p></jats:sec> <jats:sec> <jats:title>CONCLUSIONS</jats:title> <jats:p>This is the first study evaluating the interaction between OIHDs and programmable VP shunt valves. The findings suggest that it is safe to use these devices together without having to switch to a nonprogrammable valve or move the shunt valve to a more distant location. Still, care should be taken if the Sophono device is used to ensure that the valve is ≥ 5 mm away from the magnetic attachment.</jats:p></jats:sec>

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

“…[ 6 ] Lastly, a recent study demonstrated alterations in valve settings by osseointegrated hearing devices due again to their juxtaposition. [ 7 ]…”

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

“…This is consistent with a prior report that showed that a rotational component of the magnet in devices can cause reprogramming of a valve at the source (i.e., direct contact at 0 mm). 19 During this preliminary testing, we found that compared with the Codman Certas Plus valve, the Strata II valve was more likely to have valve setting changes. The setting on the Codman Certas Plus valve was not altered in any of the preliminary trials with the strong magnet.…”

“…However, it is known that magnetic flux density decreases in inverse proportion to the square of the distance from the magnetic pole, and it is possible that the use of many of these devices will be safe in real-life scenarios, where valves are placed below the scalp surface and a few centimeters away from the ear. [18][19][20] As wearable technology continues to permeate mainstream living, blanket restrictions on the use of devices capable of generating small MFs near shunt hardware will become an increasing burden on patients with these devices. There is a clear need to provide specific answers to patient questions about technology restrictions.…”

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 .…”