Mi1000 CONCERTO ABI Mi1000 CONCERTO PIN ABI - Med-El
Contents
1. Cochlear Implants VI E D 9 FL Surgical Guideline M 1000 CONCERTO ABI M 1000 CONCERTO PIN ABI Introduction The MED EL CONCERTO CONCERTO PIN Auditory Brainstem Implant System serves to restore some sense of hearing by electrical stimulation of the cochlear nucleus CN It is the result of many years of research and is intended for use in patients with non functional cochlear nerves This Surgical Guideline describes proper techniques for implanting the Mi1000 CONCERTO CONCERTO PIN Auditory Brainstem Implant ABI hereafter referred to as the CONCERTO CONCERTO PIN ABI It serves as additional information for professionals and should not be used as an Instructions for Use MED EL implants are manufactured to the highest quality standards in order to ensure long term reliability All materials used in the implant have been rigorously tested for biocompatibility durability and reliability MED EL applies a quality management system that meets all EN ISO 13485 2003 requirements and complies with US Quality System Regulations and Canadian Medical Device regulations CAN CSA ISO 13485 2003 Components of the MED EL Cochlear Implant System meet the requirements for AIMD 90 385 EEC and MDD 93 42 EEC The information in this Surgical Guideline is believed to be true and correct however some specifications may be subject to change without notice For country specific information please see the applicable Instruction for Use delivered wi2. Stimulus Figure 12 Theoretical EABR recording stimulation of the cochlear nucleus Waring 1993 Surgical tools IV Surgical tools Note that the surgical tools supplied by MED EL should not be modified in any way Modification of any of the tools is done at the surgeon s own risk Detailed instruction of the reprocessing process and the individual preparation before cleaning the tools can be found in the appropriate Instruction for Use This isa collection of tools for implantation of the CONCERTO CONCERTO PIN ABI Implant Mi1000 Implant Template PIN Order number Shipped with the implant PIN Drill Guide SI 09906 Processor Template 01557 Skin Flap Gauge 6 03543 Surgical Claw Angled 00284 Micro Forceps Angled Mi1000 Implant Template Mi1000 Implant Template PIN Shipped with the implant This template is used to assess the size and the position of the implant on the skull This tool is delivered in a sterile packaging and is a single use device only 05761 05777 05778 Figure 13 Mi1000 Implant Template Mi1000 Implant Template PIN 15 Surgical tools PIN Drill Guide SI Order Number 09906 The PIN Drill Guide SI is a re usable surgical instrument for creation of defined holes on the skull for the fixation pins of the CONCERTO PIN Cochlear Implant It consists of a PIN Drilling Template made of titanium and a Clamping Handle made of stainless chomate steel The device is es
3. 0 6 mm rounded edges Figure 21 FENTEXmedical Forceps Figure 22 AESCULAP Micro Forceps bayonet shaped 17 General remarks about the surgery V General remarks about the surgery The implant is fixed in a bed drilled in the mastoid and the ABI electrode array is inserted into the lateral recess LR of the IV ventricle The implant position should maximize the available electrode lead Surgical notes a b c d e f Sterility of the Implant CONCERTO CONCERTO PIN ABI the ABI Placing Electrode and the ABI Connector Cable must be ensured at all times Prophylactic use of antibiotics is recommended for all patients unless medically contraindicated The surgeon should prescribe adequate dosing for each patient s condition The CONCERTO CONCERTO PIN ABI electrode array Shall be inserted into the lateral recess without compressing the electrode lead or touching the electrode contacts Only MED EL approved and recommended surgical instruments should be used during the insertion process other instruments probes hooks forceps tweezers etc can damage the electrode or the other parts of the device The implant contains a strong magnet Never use magnetic surgical tools The stimulator shall be securely anchored in a bed drilled in the mastoid bone and the electrode lead protected in a bony channel without sharp edges in such a way that there will be no postoperative movement Movement
4. 30 31 31 31 32 32 32 33 33 35 25 36 37 37 Patient selection and evaluation Patient selection and evaluation Indication The CONCERTO CONCERTO PIN ABI is used for electrical stimulation of the cochlear nucleus CN via an implanted stimulator and a specially designed electrode array to evoke auditory sensations in patients with non functional cochlear nerves Likely cause of damage may include trauma inflammation or in most cases the degeneration of the cochlear nerve e g related to a bilateral acoustic neurinoma Neurofibromatosis 2 NF2 Selection and Evaluation If patients suffering from NF2 it is the responsibility of the surgeon to determine for each patient if implantation of the device during tumor removal surgery is appropriate Most NF2 patients also suffer from multiple tumor formations in the spine The personal situation of these patients may therefore be very difficult and critical Patients who are selected for an ABI implantation should have a stable psychological status and be willing to learn to use the ABI system To obtain the optimal benefit from the implant candidates must be sufficiently motivated and must understand the importance of returning to the implant center for regular audio processor programming training and assessment sessions Preoperative psychological tests shall be performed In addition to the mental condition of the patient the physical condition Shall also be assessed
5. Make sure that the connection is as shown in Figure 10 The ABI Connector Cable shall lead out of the immediate patient environment and shall be connected to the ABI Stimulator Box used for ABI Placing Electrode only The ABI Stimulator Box is driven via an inductive link by the MED EL hardware interface system which triggers the EABR measurement system It is also possible that the EABR measurement system triggers the MED EL hardware interface system Note The integrity of the electrical pathway between the ABI Placing Electrode ABI Connector Cable and the ABI Stimulator Box and the functioning of the ABI Stimulator Box shall be checked before starting the EABR Figure 9 Correct connection of the ABI Placing Electrode measurement with a telemetry measurement of channel with the ABI Connector Cable one This measurement shall be done with the selector switch position 1 2 and 3 4 Make sure that the ABI Placing Electrode Is inserted into the lateral recess ABI Connector Cable ee EEG Electrodes Stimulator Box E Q EABR Recording System gt ABI Placing Electrode Trigger out Trigger in Figure 10 Setup for EABR recording with ABI Placing System 10 Set up and recommended measurement for eABR recording Set up for CONCERTO CONCERTO PIN ABI System CAUTION a Prior the EABR measurement impedance telemetry should be performed For the EABR set up using CONCERTO CONCERTO PIN ABI syst
6. the electrical current and cause a system failure The surgeon Shall not use an electroscalpel while operating close to the CONCERTO CONCERTO PIN ABI electrode Electroscalpel use during operations not close the electrode poses no risk for the implant STEP 1 Placement of the EABR Recording Electrodes After the patient is in a semi sitting position as recommended above the EEG electrodes are placed on the contralateral mastoid negative on the vertex positive and on the lower forehead ground These electrodes shall be connected during surgery to the EABR recording system Also refer to the section 5 Set Up and Recommended Measurement for EABR Recording 19 Surgical procedure STEP 2 Mark Implant Position Place the Processor Template behind the ear and position the Mil1000 Implant Template There are various orientation options A suggested orientation for each ear is shown in Figure 23 and Figure 24 but the orientation depends on various factors like e g the curvature of the Skull Make sure that the length of the electrode lead allows placement of the electrode paddle without compressing or extending the lead The available length of the electrode lead is depending on the position of the implant bed Rotating the implant clock or counterclockwise might increase the available length Position the implant template in such a way that the CONCERTO CONCERTO PIN ABI will be in the hair bearing area The lower part of th
7. RI scanning e MRI scanner with static magnetic field strength of 0 2T 1 0T or 1 5T only No other field strengths are allowed When using other field strengths injury to the patient and or damage to the implant are possible e MRI scan not earlier than 6 months post implantation Performing an MRI at an earlier stage may result in implant displacement and or damage to the implant e A minimum thickness of the bone underneath the implant magnet of 0 4mm is required in order to withstand forces of 5N equals a gravitational force of about 0 5kg or up to 9N for the C40 cochlear implant In an MRI scanner torque forces act on the implant magnet exerting rotational pressure the device will try to turn to line up with force lines The resulting forces on the edges of the implant are counterbalanced by the cranial bone and the skin flap Bone underneath the implant magnet should be thick enough to withstand these exerting forces e Patients with mechanically damaged implants must not undergo MRI Ignoring this guideline could result in injury to the patient Safety Guidelines e Before patients enter any MRI room all external components of the implant system audio processor and accessories must be removed For field strengths of 1 0T or 1 5T a supportive head bandage must be Dlaced over the implant A supportive head bandage may be an elastic bandage wrapped tightly around the head at least three times refer to Figure 44 Th
8. asured impedance values shall be lower than the values measured at the switch position before Acceptance criteria The difference of the measured impedance values between each step shall be greater than 0 4 kQ All measured values shall lie between 1 5 kQ and 9 KQ If the measured values fulfill the acceptance criteria the ABI Stimulator Box can be used for intra operative stimulation together with ABI Placing Electrode and the ABI Connector Cable Note Only the impedance value measured at Channel 1 Shall be used as information for the pre use check All other channels show HI High impedance as measured values If the measured values do not fulfill the requirements please return the ABI Stimulator Box to MED EL for maintenance ee y Stimulator Box El for ABI Placing Electrod TORT Medical Electonics ectrode Figure 7 Correct connection of the ABI Stimulator Box Test Device to the ABI Stimulator Box ABI Stimulator Box Test Device ABI Stimulator Box PC with ao MED EL application software MED EL hardware interface system Figure 8 Set up of Telemetry System Set up and recommended measurement for EABR recording ll Set up and recommended measurement for EABR recording Set up for ABI Placing System Before starting the measurement the ABI Placing Electrode shall be connected to the ABI Connector Cable via the Micro D Plug see Figure 9 for correct connection Note
9. by the periosteum and the galea flap which has in contrast to the normal Skin incision in acoustic neurinoma surgery a mirrored question mark shape on the left and a regular question mark shape on the right side The wound should De closed in layers No drainage is used The area of the wound is covered with a compress and sterile gauze applying even pressure Remark for initial fitting CAUTION er The initial fitting of the audio processor is done typically six to eight weeks after surgery The fitting shall be performed in the intensive care unit of the hospital or in the presence of an intensive care crash cart 34 Figure 40 Platinum bridge Figure 41 Lifting of the platinum bridge CONCERTO DEMO Figure 42 Pull out left side Figure 43 Platinum bridge removed Appendix Appendix MRI Caution MRI is possible in patients with cochlear or auditory brainstem implants only with specified models of MRI machines Evidence has been provided for these implants to pose no known hazard in magnetic field strengths of 0 2T 1 0T and 1 5T without surgical removal of the internal magnet when the following safety recommendations and guidelines are adhered to The physician MRI operator should always be informed that a patient is a cochlear implant or an auditory brainstem implant user and that special safety recommendations and guidelines have to be followed Safety recommendations and guidelines for M
10. d burr should be used to drill the holes so that the implant can be immobilised later The suture holes should be drilled such that the sutures do not cross the electrode but rather only cross the silicone over mold see Figure 30 26 Figure 29 Marking the implant position with the Implant Template right ear Figure 30 Flat stimulator bed electrode channel and suture holes for single stitch right ear Surgical procedure STEP 8 B CONCERTO PIN The Mi1000 Implant Template PIN can be used to mark the correct position of the stimulator and the electrode channel see Figure 31 The temporal bone area in which the stimulator is placed must be flattened to ensure sufficient stimulator immobilisation The flattening also ensures a flat stimulator position without a later rocking of the implant and enables a good positioning of the pins in the drilled holes see Figure 32 The immobilisation of the CONCERTO PIN ABI with the two pins and an additional suture over the stimulator stabilizes the stimulator against translational and rotational motion Furthermore the electrode lead should be protected in a ramp like bony channel without sharp edges which is drilled into the skull It is important to ensure that the channel is deep and wide enough to comfortably accommodate the electrode This protect the electrode lead against postoperative movement and excessive mechanical impact Sy e Figure 31 Marki
11. d in a leak proof disinfected or sterile container filled with saline and returned to MED EL Headquarters The device should Figure 47 X ray of CONCERTO PIN Cl Courtesy of be accompanied by written information including the University of Innsbruck reason for explantation 37 Appendix Literature on ABI Auditory brainstem implants for neurofibromatosis type 2 Colletti L Shannon R Colletti V Curr Opin Otolaryngol Head Neck Surg 2012 Aug 9 Auditory brainstem implantation Sennaroglu L Ziyal Auris Nasus Larynx 2012 Oct 39 5 439 50 Epub 2011 Dec 22 Early surgical results of auditory brainstem implantation in nontumor patients Choi JY Song MH Jeon JH Lee WS Chang JW Laryngoscope 2011 Dec 121 12 2610 8 Complications in auditory brainstem implant surgery in adults and children Colletti V Shannon RV Carner M Veronese S Colletti L Otol Neurotol 2010 Jun 31 4 558 64 Preliminary results of auditory brainstem implantation in prelingually deaf children with inner ear malformations including severe stenosis of the cochlear aperture and aplasia of the cochlear nerve Sennaroglu L Ziyal l Atas A Sennaroglu G Yucel E Sevinc S Ekin MC Sarac S Atay G Ozgen B Ozcan OE Belgin E Colletti V Turan E Otol Neurotol 2009 Sep 30 6 708 15 Outcomes in nontumor adults fitted with the auditory brainstem implant 10 years experience Colletti V Shannon R Carner M Veronese S Colletti L Otol Neurot
12. de should be placed into the drilled channel leading into the mastoid Make sure the electrode channel is deep enough to prevent the tie down from exerting pressure and damaging the electrode MED EL recommends the use of the following techniques details in Figure 36 Figure 37 30 Figure 36 Implant immobilised with a single stitch right ear Figure 37 Implant immobilised with double stitches right ear Surgical procedure STEP 9 B CONCERTO PIN CAUTION e If monopolar diathermy has been used it must now be disconnected High current levels may cause damage to the implant If bipolar cautery must be used the tips of the cautery should be kept at least 3 cm away from the implant e Recessing the pins and efficient immobilisation of the stimulator is important to prevent postoperative movement e Do not place the sutures directly over the electrode lead The area of the temporal bone on which the stimulator will be placed shall be flattened in order to ensure that the implant is sufficiently immobilised The two pins of the CONCERTO PIN Cochlear Implant should be recessed into the skull with the PIN Drill Guide SI to a depth of 1 5mm The electrode lead should be placed in a ramp like bony channel without sharp edges to protect it against postoperative movement and excessive mechanical impact The two pins give additional stability against translational and rotational motion Recessing the pins and effic
13. dle made of stainless chromate steel The device is delivered non sterile 16 Figure 19 Surgical Claw Straight Figure 20 Mi1000 PIN Drill Guide Surgical tools FENTEXmedical Forceps FENTEXmedical GmbH is specialized in the development manufacturing and marketing of surgical instruments and visualization systems for ENT Head amp Neck and Facial Surgery Basic description of the device Cl Electrode Insertion Forceps L 155 mm with longitudinal eroove for electrodes with a basal diameter in the range 0 8 1 3 mm FENTEXmedical forceps have been successfully tested at headquarters with all MED EL electrode arrays This surgical tool is no MED EL product and may therefore be ordered directly at your local FENTEXmedical distributor http www fentexmedical com AESCULAP Micro Forceps bayonet shaped It is recommended to use a micro forceps bayonet shaped 200 mm long and with rounded edges at the tip with a width of 0 6 mm during placement of the ABI electrode array and the ABI Placing Electrode to protect the leads of the electrodes against damage This is a standard surgical tool for brain surgery This tool is a re usable surgical instrument made from medical grade stainless steel The device is delivered non sterile Supplier AESCULAP AG amp CO KG Am AESCULAP Platz D 78532 Tuttlingen Germany Technical Data Micro forceps bayonet shaped Yasargil profile handles 200 mm long Width at the tip
14. e bandage shall fit tightly but should not cause pain Head orientation In case of 1 0T and 1 5T systems the longitudinal axis of the head must be parallel to the main magnetic field of the scanner For example this is the case when the patient is in a supine position with the head kept straight The patient should not turn or bend his her head to the side otherwise partial demagnetization of the implant magnet is possible In case of 0 2 T scanners no specific head orientation is required Sequences in Normal Operating Mode shall be used only During the scan patients might perceive auditory sensations such as clicking or beeping Adequate counseling of the patient is advised prior to performing the MRI The likelihood and intensity of auditory sensations can be reduced by selecting sequences with lower specific absorption rate SAR and slower gradient slew rates Figure 44 Head bandage to support fixation of the implant 39 Appendix 36 Image artifacts are to be expected refer to Figure 45 The above instructions should also be followed if areas of the body other than the head are to be examined e g knee etc When lower extremities are to be examined it is recommended that the patient s legs are positioned in the scanner first to minimize any risk of weakening the implant magnet e The above instructions also apply for patients with bilateral cochlear implants or bilateral auditory brainstem implan
15. e implant either sterile gauze drenched in saline solution or the skin flap should be placed between the coil and the implant Moistening the underside of the skin flap with sterile Saline or pooling saline over the ground electrode of the implant prior to performing intra operative recordings may Improve readings IFT Impedance Field Telemetry After the implant is in place a telemetry check allows e individual electrode impedance measurements e verification of the absence of short and open circuits between electrodes e determination of voltage distribution across the cochlear nucleus As with any telemetry system intra operative impedance testing may not provide an accurate representation of later electrode function High values observed intra operatively may be caused by air bubbles on the electrode contact surface These generally dissipate within a few hours or days after surgery 32 EABR Electrically Evoked Brainstem Response For details regarding EABR please refer to the section Ill Set up and recommended measurement for EABR recording STEP 11 Implantation Procedure with EABRs After fixation of the stimulator the ABI Active Electrode Shall be placed The polyester mesh which is embedded in the silicone of the ABI electrode array is cut to fit in the lateral recess and the ABI electrode array is placed into the estimated correct location Go on with the procedure in STEP 12 EABR Measurements during S
16. e stimulator should be under or close to the temporal line with an angle between 35 and 60 The electrode exits on the lateral side of the implant Therefore the electrode lead comes out superiorly for the left ear and inferiorly for the right ear Once the implant template is in place surgical ink may be used to mark its position on the surface of the skin Surgeons may choose to transpose the position of the implant template onto the surface of the bone by using a hypodermic needle inserted perpendicularly to the skin at points along the side of the implant template When implanting a patient bilaterally care should be taken of the placement of the implants In particular the second side should be placed specifically to match the location of the first to give symmetric appearance of the external part The skull curvature and pinna position needs to be taken into consideration when placing the second implant in a similar location as the contralateral side 20 Figure 23 left ear Suggested orientation of the templates Figure 24 right ear Suggested orientation of the templates Surgical procedure STEP 3 Plan Incision Choose the line of Incision so that a well vascularised skin flap results Make the incision 1 2 cm from the implant to ensure that the scar will not lie directly over the body of the implant Incise the tissue with a scalpel and use bipolar electrocoagulation for hemostasis An example of a co
17. ecording This measurement via the implant should be used as a final check The results from the ABI Placing Electrode are primarily used for the determination of the stimulation site STEP 14 Fixation of the Electrode CAUTION Improper fixation or placement of the ABI electrode array may result in dislocation This is true especially when a large lateral recess is present The ABI Active Electrode can be prefixed onto the brainstem surface with a piece of hemostyptic material and fibrine glue to prevent postsurgical displacement The main fixation is achieved by gluing the electrode lead to the rostral surface of the cerebellum Useful for this procedure is a collagen foam covered with instant glue TachoComp 33 Surgical procedure STEP 15 Removal of the Platinium Bridge on the Implant Housing The platinum bridge Figure 40 on the implant housing shall be removed with forceps The platinum bridge is fixed with silicone only on its edges This allows the lifting of the platinum bridge Figure 41 from the surface of the implant Pull out the whole platinum bridge Figure 42 and Figure 43 Make sure that there is no residual platinum foil on the implant housing Figure 43 STEP 16 Closing the wound After implantation the dura shall be closed in a watertight fashion The entry of the electrode lead into the dura is sealed with fibrin glue or TachoComp The housing is covered in a double layer technique
18. ectrode is 3 7 cm e The electrode is made of medical grade silicone platinum electrode contacts and platinum iridium 90 10 wires and nitinol e All electrode variants have a straight and flexible design The electrode does not deliver any medicinal substances e Geometric surface area of the stimulation reference electrode 50mm Following materials are in direct contact with human tissue medical grade silicone platinum iridium ABI Active Electrode Order number CONCERTO ABI 07675 Order number CONCERTO PIN ABI 07681 The ABI Active Electrode has an oval shaped flat silicone paddle electrode array with 12 active contacts and 1 reference contact A polyester mesh embedded in silicone exceeds the size of the silicone paddle This paddle is Slightly pre shaped to fit onto the curved brain surface An additional contact Is placed in the center of the silicone paddle to allow bipolar stimulation mode during intraoperative measurement The diameter of the electrode lead increases from 0 7 mm at the silicone paddle to 1 3 mm over a length of 10 mm Designed Especially for Neurofibromatosis Type Il ABI is a solution for individuals with hearing loss due to a non functioning auditory nerve Neurofibromatosis Type Il Bypassing both the inner ear and the auditory nerve the MED EL ABI stimulates the cochlear nucleus CN and provides users with a variety of hearing sensations to assist with sound awareness and co
19. el 1 for stimulation during intraoperative measurement Note The selection of the active contact pair at the ABI Placing Electrode is made with the selector switch of the ABI Stimulator Box The selected stimulation configuration 1 2 1 3 1 4 2 3 2 4 3 4 can be chosen via the selector switch The selected stimulation configuration shall not be changed during stimulation in order not to influence the measured EABR curves Stimulation parameters The stimulation parameters are set via the MED EL application software Note This setting shall be done by trained personnel only The measurement typically starts with an electrode configuration of 1 4 selected with the ABI Stimulator Box The stimulation parameters are set to pulse duration of 30 us phase and a stimulation current of 300 cu current units Note The following limits shall not be exceeded 1000 cu e 150 us Extended setup For EABR recording single stimulus pulses are used Alternating pulses can be used to reduce the stimulus artifact Leave the HF signal turned on Stimulation rate between 10 Hz and 35 Hz 12 EABR curve Wave IIl generated at the cochlear nucleus is normally overlapped by the stimulus artifact during EABR recording Waves IV and V become visible at a latency of 1 to 2 ms Note Figure 12 shows a theoretical recording During intraoperative EABR measurements only one wave IV or V is visible at the recording monitor II Time
20. em the coil from the MED EL hardware interface system is directly placed on the CONCERTO CONCERTO PIN ABI implant Figure 11 Before starting the measurement the ABI Electrode shall be placed on the brainstem Recommended measurement for EABR recording EEG Electrode Placement Before surgery EEG Electrodes are placed on the contralateral mastoid negative on the vertex positive and on the lower forehead ground These electrodes are connected during surgery to the EABR recording system Try to avoid placing any two electrodes too close together Impedance of EEG Electrodes The impedance of any recording electrode should be less than 2 kQ There should be no greater difference between the individual electrode impedanceless than 2 kQ Trigger out General set up of the EABR measurement system Window 10 ms Points 256 Gain 20 000 50 000 Hi filter 3000 Hz Lo filter 30 100 Hz Sweep 200 1500 Trigger external MED EL hardware interface system triggers the EABR measurement system Note It is also possible that the EABR measurement system triggers the MED EL hardware interface systems internal EEG Electrodes B EABR Recording System Trigger in Figure 11 Setup for EABR recording with CONCERTO CONCERTO PIN ABI implant 11 Set up and recommended measurement for eABR recording Using the MED EL application software EABR Task Channel selection for ABI Placing System Select chann
21. for an implantation Tumor size and cochlear nerve condition should be assessed preoperatively either by performing MRI and or CT scanning and electrophysiological measurements ABR EABR eCochG Also a preoperative spinal MRI is essential Experienced Neuro and ENT surgeons shall decide in accordance with the test results and their own personal experience if a patient is a suitable candidate for an ABI implantation If previous irradiation of the tumor has taken place the patient s evaluation should include possible structural deformation caused by such irradiation Large structural deformation may prevent proper ABI placement and should be evaluated by the surgeon Before surgery the patient must be informed about the function of the implant the risks of surgery and implantation realistic expectations and rehabilitation plans after surgery A personal conversation between patient and surgeon Should help the patient to gain a general idea about the device and to estimate risks and benefits of the Implant CONCERTO CONCERTO PIN ABI This device is to be used by surgeons who have been trained in the surgical placement of an Auditory Brainstem Implant Technical description of the ABI System ll Technical description of the ABI System The CONCERTO CONCERTO PIN ABI is the implantable part of the MED EL Cochlear Implant System and can only be Bilun used together with compatible MED EL external componenis The device consists
22. from tumor tissue and functionally preserved with this method A suboccipital approach is recommended by the expert surgeons who shared their experience for these guidelines The opening in the skull normally has a diameter of 25 35 mm The brain is retracted from the skull with a dissector for obtaining access to the region of the cochlear nerve For ABI implantation via a suboccipital approach a retrosigmoidal trepanation is used If the opening is not located correctly too high or too far back the lead of the Auditory Brainstem Implant may be too short and the CONCERTO CONCERTO PIN ABI electrode array not placeable in the lateral recess A correct location of the trepanation is therefore of high importance 24 STEP 6 Preparation of the Lateral Recess After complete tumor resection the exits of the nerves VIL VIII and the caudal groups IX and X from the brainstem shall be identified Then the flocculus of the cerebellum is identified and smoothly retracted in a small amount In most cases the choroid plexus of the IV ventricle is then exposed The arachnoid membrane covering these structures Is then gently dissected The preparation should be directed towards the space between plexus and Drainstem All vessels supplying the brainstem must be preserved Thereafter a 45 inclinated dissector can be Inserted into the lateral recess This can be facilitated by additonal retraction of the cerebellar hemisphere Care mu
23. ibutor for the latest MED EL Surgical Videos or visit the MED EL Professional Webpage www medel com professionals MED EL Contacts For MED EL Contacts please visit the MED EL Webpage www medel com contact offices 39
24. icro Forceps is used to Insert the electrode depends on the preference of the surgeon In the closed position the tips of the forceps are parallel to each other separated by a distance of 0 25 mm This tool is a re usable surgical instrument for transient use made from medical grade stainless steel The device is delivered non sterile Surgical Claw Angled Order number 00284 The claw can help to position and manoeuvre the electrode This tool is a re usable surgical instrument for transient use made from medical grade stainless steel The device is delivered non sterile Figure 17 Micro Forceps right angled Micro Forceps left angled Figure 18 Surgical Claw 15 Surgical tools The following tools are additions to the surgical kit and may be ordered separately Surgical Claw Straight Order number 07711 The Surgical Claw can help to position and insert the electrode array into the cochlea The tip of this instrument is straight This tool is a re usable surgical instrument made from medical grade stainless steel The device is delivered non sterile M 1000 PIN Drill Guide Order number 07613 Consisting of Mi1000 PIN Stimulator Template 07748 The Mi1000 PIN Drill Guide is a re usable surgical instrument for creation of defined holes in the skull for the pins of MED EL hearing implant housing variants with pins It consists of a Mi1000 PIN Stimulator Template made of titanium and a Clamping Han
25. ient immobilisation of the stimulator e g with sutures is important to prevent postoperative movement Continuous movement may result in mechanical fatigue and subsequent premature failure of electrical connections When the implant is immobilised with sutures holes drilled into the bone should be used to secure the implant in its flat area and the electrode should be placed into the drilled channel leading into the mastoid Ensure that the electrode channel is deep enough to prevent the tie down from exerting pressure and damaging the electrode MED EL recommends the use of different immobilisation techniques details on Figure 38 Figure 39 Figure 38 Implant immobilised with a tight periosteum pocket right ear Figure 39 Implant immobilised with stitches right ear 31 Surgical procedure STEP 10 Intra operative Recordings At this stage intra operative recordings like Impedance Field Telemetry IFT and Electrically Evoked Brainstem Response EABR can be performed Intra operative measurements are performed with the appropriate MED EL application software and the MED EL hardware interface system For details please refer to the applicable User Manual It is not possible to sterilise any component of the MED EL clinical interface system When used in a Sterile environment the coil and cable should be covered with sterile material i e sterile sleeve Since the coil should not be placed directly on th
26. mmonly used postaural incision is shown in Figure 25 and Figure 26 Postaural incisions start in the sulcus behind the pinna and extend posteriorly For greater mastoid bone exposure each of these incisions can be extended posteriorly in the shape of an arc Figure 25 Minimal incision left picture and lazy S incision right picture right ear 7 4 Figure 26 Minimal incision left picture and lazy S incision right picture right ear close up 21 Surgical procedure STEP 4 A Open Skin Flap The incision is made and the wound is held open by retractors At all times care should be taken to ensure that the flap is kept moist with damp surgical gauze Either a single layer skin flap all four layers skin subcutis muscle and periosteum are incised in a single cut or a double layer skin flap can be performed A double layer skin flap may e reduce the chance of infection because the incisions are at different locations and layers and e allow better healing so it is often used for re implantations and when encountering postauricular scar formation Double layer skin flap see Figure 27 The four different tissue layers skin subcutis muscle and periosteum are incised with two different incisions First the skin subcutis and muscle are raised and retracted Second the periosteum Is incised the periosteum Is freed from the surface of the bone and then retracted in another l
27. mmunication Ne 7 a Ps D DG O 1 gt T gt gt gt S Die Om Yio Fa n 4 KA gt ABI Electrode Array Featuring 12 contacts arranged on a soft pre shaped silicone paddle Shaping Arms Back Side Active Stimulation Contacts Reference Contact Polyester Mesh Diameter at basal end 1 3mm 2 12 x 0 55mm active stimulation contacts 1 x 0 75mm reference contact Paddle size 5 5mm x 3mm The ABI electrode array features 12 active contacts on a soft pre shaped silicone paddle with shaping arms fixed to a polyester mesh Figure 2 ABI Electrode Array dimensions in mm typical values Technical description of the ABI Placing System ABI Placing System CAUTION For detailed information on the ABI Placing System MED EL hardware application software please refer to the applicable Interface system and MED EL instruction for use and user manual The ABI Placing System for the Implant CONCERTO CONCERTO PIN ABI is designed exclusively for transient intraoperative stimulation of the cochlear nucleus During stimulation of the cochlear nucleus Electrical Evoked Auditory Brainstem Responses EABR shall be recorded to estimate the best position for the ABI electrode array The ABI Placing System consists of e ABI Placing Electrode ABI Connector Cable ABI Stimulator Box p 1 3 ABI Placing Electrode The electrode array and the lead of the ABI Placing Elec
28. n of the electrode configuration at the ABI Placing Electrode which is used for bipolar stimulation during EABR measurements 2000 Left side Right side Figure 4 ABI Connector Cable dimensions in mm typical values Output plug for the ABI Connector Cable see Figure 6 Selector switch for choosing the electrode configuration Contact arrangement on the ABI Placing Electrode seen from the top NOT contact side Stimulator Box 4 for ABI Placing Position for placement Bectenis Electrode of the coil from the MED EL hardware interface system Figure 5 ABI Stimulator Box Output Plug for ABI Connector Cable Figure 6 ABI Stimulator Box Technical description of the ABI Placing System Prior to the use of the ABI Placing System a pre use check shall be performed with the ABI Stimulator Box Note Only personnel trained on the use of the MED EL telemetry system shall perform the pre use check The following steps shall be followed when performing the pre use check Setup of measurement Connect the ABI Stimulator Box Test Device to the ABI Stimulator Box Telemetry Start the telemetry measure 1 gt 4 2 gt 3 1 gt 3 2 gt 4 9 T ments at the selector switch configuration 1 gt 2 and pro ceed clockwise 20 0 e TOP VIEW Note The impedance measured at switch position 1 gt 2 Shall be lower than the impedance measured at switch position 1 gt 3 All subsequently me
29. ng the implant position with the Implant Template right ear Figure 32 Flattening of the stimulator area right ear 27 Surgical procedure Thetwo pins of the CONCERTO PIN ABI should be recessed into the skull with PIN Drill Guide SI or the Mil000 PIN Drill Guide to a depth of 1 5mm see Figure 33 The PIN Drill Guide SI or Mi1000 PIN Drill Guide is used to support the drilling of the holes of the fixation pins into the skull in a defined distance and depth For drilling the holes into the flat area the following methods can be used 28 Figure 33 CONCERTO PIN ABI Dimensions of the pins Surgical procedure PIN Drill Guide SI and a diamond burr of 1 0 mm CAUTION e Ensure that the dura is not inadvertently damaged when drilling the holes e Always use a slow turning drill e g 2000 rpm e Stop drilling when a depth of 1 5 mm is achieved Use the diamond burr of 1 0 mm to mark both hole positions and drill through the PIN Drill Guide SI Avoid recessing the pins deeper than 1 5 mm see Figure 34 PIN Drill Guide SI and a surgical pen Surgical ink CAUTION lt lt e Ensure that the dura is not inadvertently damaged when drilling the holes e Use a diamond burr of 1 0 mm for drilling the holes e Always use a slow turning drill e g 2000 rpm e Stop drilling when a depth of 1 5 mm is achieved When using a Surgical pen or surgical ink for marking the position of the holes through the PIN D
30. ocation Various methods may be used when incising the periosteum Care should be taken to avoid incision over the implant later on 22 Figure 27 Double layer skin flap right ear Surgical procedure STEP 4 B Skin Flap Thickness In order to achieve good magnetic hold and optimal signal transmission the skin flap or the muscle may need to be thinned out so it does not exceed 6mm Evaluate the portion of the flap over the magnet and receiving coil with the Skin Flap Gauge 6 as shown in Figure 28 If the flap does not fit in the gauge loosely carefully thin the flap until it does It is important to avoid over thinning of the flap which may result in wound complications Care must be taken to avoid exposing hair follicles Figure 28 Using the Skin Flap Gauge 6 right ear 23 Surgical procedure STEP 5 Tumor Removal Surgerv If necessary the acoustic neuroma is removed in a standard tumor removal surgery Either a suboccipital or a translabyrinthine approach can be used for this surgery A suboccipital approach makes the preservation of the cochlear nerve during tumor removal possible due to a lateral perspective By stimulating the tissue in the area of the cochlear nerve and measuring EABR potentials intraoperatively with special ball electrodes the boundary between tumor and nerve tissue can be determined electrophysiologically If the cochlear nerve is not yet destroyed by the tumor it can be uncovered
31. of a stimulator a coil with a magnet within its centre a reference electrode an EAP reference electrode and an active electrode permanently attached to the stimulator This device is intended to be implanted by adequately trained and experienced surgeons only reference electrode 1114 EAP reference electrode The CONCERTO CONCERTO PIN ABI has been designed according to the highest safety and reliability standards All materials used in the construction of the CONCERTO CONCERTO PIN ABI have been extensively tested for biological compatibility and durability The power required 2 d by the implant is transmitted from the external audio processor through the intact skin via an inductive link The implant therefore contains no batteries or other components that require replacement The implant offers a stimulation mode and a telemetry mode Stimulation sequences of biphasic and triphasic pulses can be delivered sequentially or simultaneously on two or more channels In telemetry mode the device allows a functional check about the technical status of the implant including communication over the transcutaneous link as well as the assessment of the electrode impedances and recording of the electrically Channel allocation evoked compound action potential of the hearing nerve The electronics of the CONCERTO CONCERTO PIN ABI contain a powerful custom made circuit that is capable of processing la
32. ol 2009 Aug 30 5 614 8 Bilateral electric stimulation from auditory brainstem implants in a patient with neurofibromatosis type 2 Skarzynski H Behr R Lorens A Podskarbi Fayette R Kochanek K Med Sci Monit 2009 Jun 15 6 CS100 4 The High Rate CIS Auditory Brainstem Implant for Restoration of Hearing in NF 2 Patients Behr R Muller J Shehata Dieler W Schlake HP Helms J Roosen K Klug N Holper B Lorens A Skull Base 2007 Mar 17 2 91 107 38 The first successful case of hearing produced by electrical stimulation of the human midbrain Colletti V Shannon R Carner M Sacchetto L Turazzi S Masotto B Colletti L Otol Neurotol 2007 Jan 28 1 39 43 Three year experience in the rehabilitation of brainstem implant patients H Skarzynski R Behr J Szuchnika A Lorens R Zawadzki A Walkowiak B Skarzynska A Piotrowska L Sliwa International Congress Series 1240 2003 429 432 An auditory brainstem implant system Jackson KB Mark G Helms J Mueller J Behr R Am J Audiol 2002 Dec 11 2 128 33 First auditory brainstem implantation in Poland auditory perception results over 12 months Skarzynski H Szuchnik J Lorens A Zawadzki R J Laryngol Otol Suppl 2000 27 44 5 Intraoperative Electrophysiologic Monitoring to assist Placement of Auditory Brain Stem Implant Waring M Ann Otol Rhinol Laryngol Suppl 1993 Sep 33 36 Appendix MED EL Surgical Videos Please contact you local MED EL office or distr
33. pecially recommended for surgeons using a small INCISION This tool is a re usable surgical instrument for transient use The device is delivered non sterile Processor Template Order number 01557 The Processor Template TEMPO OPUS template shows the minimum spacing which must remain free behind the ear so that the external coil and the BTE Audio Processor do not interfere with each other when worn by the patient post operatively This tool is a re usable surgical instrument for transient use made from medical grade stainless steel The device is delivered non sterile Skin Flap Gauge 6 Order number 03543 Skin Flap Gauge 6 Is used to evaluate the thickness of the Skin flap in the area covering the cochlear implant A skin flap thickness of 6 mm or less is recommended for a good magnetic hold and optimal signal transmission Skin flaps thicker than 6 mm should be thinned out This tool is a re usable surgical instrument for transient use made from medical grade stainless steel The device is delivered non sterile 14 Figure 14 PIN Drill Guide SI Figure 15 Processor Template TEMPO OPUS template Figure 16 Skin Flap Gauge 6 Surgical tools Micro Forceps Angled Order number 05761 right amp left angled 05777 right angled 05778 left angled The Micro Forceps left angled and the Micro Forceps right angled are used to grip hold and insert the electrode without damaging It Which kind of angled M
34. results in fatigue and possible subsequent failure of electrical connections Uni or monopolar diathermy may not be used after the implant is introduced into the surgical field as it may cause damage to the implant g The implant must never be dropped onto a hard surface damage to the stimulator or electrodes during the operation will invalidate the warranty h The serial number of the implant must be visible on i 18 the implant before fixing it in place Other risks after surgery may be avoided by following the instructions in the applicable MED EL CONCERTO CONCERTO PIN ABI instruction for use j In order to achieve good magnetic holding power and optimal coupling the distance between the lateral side of the implant and the surface of the skin with hair shall not exceed 6mm k Do not place the sutures directly over the electrode lead Surgical procedure VI Surgical procedure General information In general an ABI implantation is performed as a procedure for restoration of sound perception of NF2 patients immediately after resection of an acoustic neuroma Patients with other lesions involving the cochlear nerve and causing massive hearing impairment up to deafness may also be candidates For the resection of an acoustic neuroma which is the main indication for receiving an ABI it is recommended to use the semi sitting position of the patient as a result of clinical experience The head is fi
35. rge amounts of information at a very rapid rate It can stimulate at 50 704 pulses per second This capability makes the implant compatible with a wide range of pulsatile processing strategies and future developments in speech processing A telemetry feature enables the clinic to verify the functional status of the implant within a matter of seconds For added safety each output has Figure 1 Implant CONCERTO CONCERTO PIN ABI a capacitor to prevent any possible leakage of DC current dimensions in mm typical values to the auditory nerve Technical description of the ABI System Performance Characteristics e Output characteristics of a stimulation signal on a IkOhm resistor Maximum current amplitude Median value 1250UA range 500 pA Maximum pulse width Median value 203 8 us range 8 2 us e The impedance measurement accuracy is typically better than 5 e When keeping to the safety guidelines the implant is conditionally MRI safe for MR scanner field strengths of 0 2 Tesla 1 0 Tesla and 1 5 Tesla e There are no default factory settings of the implant system e Proper functioning of the implantable part of the Cl system can be checked by performing telemetry refer to MED EL application software user manual e The implant has 24 independent current sources stimulating 12 independent electrode channels in monopolar mode e The implant has a mass of 7 6g typical value e Thevolume of the implant without el
36. rill Guide SI be aware that the irrigation of the drill can wash your markings away Drying the bone with a sterile tissue helps to better mark the holes with the surgical pen or ink Use the diamond burr of 1 0 mm to mark both hole positions Then drill the full depth of the pin hole Avoid recessing the pins deeper than 1 5 mm gt ai a A 4 E A AN 4 y lt A C Figure 34 Using the PIN Drill Guide SI Figure 35 Flat stimulator area with pin holes electrode channel right ear 29 Surgical procedure STEP 9 Immobilise the Implant STEP 9 A CONCERTO CAUTION e e If monopolar diathermy has been used it must now be disconnected High current levels may cause damage to the implant If bipolar cautery must be used the tips of the cautery should be kept at least 3 cm away from the implant e Additional immobilisation of the implant needs to be performed e If sutures are chosen for immobilisation of the implant do not place the sutures directly over the electrode lead Additional immobilisation of the implant needs to be performed e g with sutures It should be conducted in such a way that there will be no postoperative movement Continuous movement may result in mechanical fatigue and subsequent premature failure of electrical connections When the implant Is immobilised with sutures the holes drilled in STEP 8 should be used to secure the implant in its bed and the electro
37. s become identifiable an ABI can be used If no EABRs are measurable a repositioning of the ABI Placing Electrode may be necessary Again EABRs shall be assessed Placement of the CONCERTO CONCERTO PIN ABI electrode in the absence of clear EABRs may only be done if the surgeon considers the anatomical landmarks to be sufficient and reliable 25 Surgical procedure STEP 8 Drilling the Implant Bed CAUTION The implant must be immobilised in a flat stimulator bed drilled in the temporal bone The electrode lead should be placed in a ramp like bony channel without sharp edges to protect it against postoperative movement and excessive mechanical impact Care shall be taken that the platinum bridge and electrode leads are not compressed by sutures or other structures i e bony rims STEP 8 A CONCERTO The implant must be immobilised in a flat stimulator bed drilled in the temporal Done In adults it may not be necessary to expose the dura but in small children with a thin skull drilling to the dura may sometimes be required in order to ensure that the stimulator is well recessed in its bed If drilling down to the dura is necessary a bony island should remain Ideally the stimulator is recessed approximately 2 mm Once again the Mi1000 Implant Template can be used to mark the flatness on the skull and the correct position for the implant bed see Figure 29 If for example the implant is fixed with sutures a diamon
38. st be taken that there are no vessels inside the recess running in cranio caudal direction Such vessels may be injured or impede implantation by narrowing or occluding the entrance to the IV ventricle Surgical procedure STEP 7 EABR Recording Prior to implantation of the Implant CONCERTO CONCERTO PIN ABI EABR measurements should be performed Connect the ABI Connector Cable and the ABI Placing Electrode via the Micro D Plug also refer to IIl Set up and recommended measurement for EABR recording The transition of the ABI Connector Cable to the ABI Placing Electrode shall not be Drought into contact with the surgery wound Connect the ABI Connector Cable located outside the patient environment to the plug of the ABI Stimulator Box used for ABI Placing Electrode only Prior to placement of the ABI Placing Electrode the anatomical facts need to be established The positioning of the ABI Placing Electrode shall be done in accordance with anatomical landmarks The lateral recess is opened 4 mm and the ABI Placing Electrode Is inserted with the recommended tools The ABI Placing Electrode has the same shape and dimensions as the CONCERTO CONCERTO PIN ABI electrode with a reduced number of contacts and no polyester mesh Care shall be taken regarding the electrode orientation the contacts shall face the brainstem surface By stimulating the brainstem with bipolar biphasic current pulses EABR potentials shall be assessed If EABR
39. th the implant system Table of contents Patient selection and evaluation Indication Selection and Evaluation Il Technical description of the ABI System Performance Characteristics ABI Placing System Ill Set up and recommended measurement for EABR recording Set up for ABI Placing System Set up for CONCERTO CONCERTO PIN ABI System IV Surgical tools V General remarks about the surgery Surgical notes VI Surgical procedure General information STEP 1 Placement of the EABR Recording Electrodes STEP 2 Mark Implant Position STEP 3 Plan Incision STEP 4 A Open Skin Flap STEP 4 B Skin Flap Thickness STEP 5 Tumor Removal Surgery STEP 6 Preparation of the Lateral Recess STEP 7 EABR Recording STEP 8 Drilling the Implant Bed STEP 8 A CONCERTO STEP 8 B CONCERTO PIN STEP 9 Immobilise the Implant STEP 9 A CONCERTO STEP 9 B CONCERTO PIN STEP 10 Intra operative Recordings STEP 11 Implantation Procedure with EABRs STEP 12 Implantation Procedure in Case of Absence of EABRs STEP 13 EABR Measurements during stimulation via the CONCERTO CONCERTO PIN ABI STEP 14 Fixation of the Electrode STEP 15 Removal of the Platinium Bridge on the Implant Housing STEP 16 Closing the wound Remark for initial fitting Appendix MRI Caution X rays Explanting the Device Literature on ABI MED EL Surgical Videos MED EL Contacts u a W OO 11 16 16 17 17 17 18 19 20 21 22 22 23 24 24 25 28 28 29 30
40. timulation via the Implant CONCERTO CONCERTO PIN ABI Surgical procedure STEP 12 Implantation Procedure in Case of Absence of EABRs To determine the best stimulation area the ABI Placing Electrode is placed into the lateral recess again EABRs are recorded by stimulating the CN in any bipolar configuration mode possible with the four contacts EABR measurements are repeated until the stimulation area has been found were all electrode combinations elicit EABRs If no EABRs can be recorded the surgeon has to decide if the anatomical landmarks are sufficiently reliable to proceed with the implantation The ABI Placing Electrode is then retracted and substituted by the ABI Active Electrode The polyester mesh which is embedded in the array is cut to fit into the lateral recess and the CONCERTO CONCERTO PIN ABI electrode array is placed in the location where the ABI Placing Electrode evoked EABRs Therefore the insertion depth into the lateral recess shall be the same for both electrodes STEP 13 EABR Measurements during stimulation via the CONCERTO CONCERTO PIN ABI Before fixation of the ABI Active Electrode a final EABR check via the implant is performed The appropriate coll of the MED EL hardware interface system is put into a sterile sleeve and placed on the implant For correct recording of potentials the MED EL hardware interface system Shall trigger the measuring device see III Set Up and Recommended Measurement for EABR R
41. trode have the same dimensions as the CONCERTO CONCERTO PIN ABI ABI electrode array The paddle has only 4 electrode contacts instead of 12 1 and there is no polyester mesh The Micro D Plug is the connective part of the ABI Placing Electrode and shall be connected to the ABI Connector Cable see section IV Set up and recommended measurement for EABR recording Micro D Plug Figure 3 ABI Placing Electrode dimensions in mm typical values Technical description of the ABI Placing System ABI Connector Cable The ABI Connector Cable is designed to transfer stimulation pulses from the ABI Stimulator Box to the ABI Placing Electrode The length of the cable is lt 2 m so that it can lead out of the patient s environment The connector on the left side of the ABI Connector Cable see Figure 4 shall be connected to the ABI Placing Electrode Micro D Plug The connector on the right side of the ABI Connector Cable see Figure 4 shall be connected to the ABI Stimulator Box see Figure 5 ABI Stimulator Box Pre use check of the ABI Stimulator Box CAUTION gt gt gt Do not use an ABI Stimulator Box for intra operative stimulation if the ABI Stimulator Box is not functioning correctly The ABI Stimulator Box generates biphasic stimulation pulses controlled by the MED EL hardware interface system via the coil placed on the ABI Stimulator Box The selector switch see Figure 5 allows easy selectio
42. ts If the conditions for MR safety and the Safety Guidelines are not followed injury to the patient and or damage to the implant may result Figure 45 MR images obtained with a 1 5T scanner 8 year old child Appendix X rays The CONCERTO CONCERTO PIN ABI can be identified by x ray post surgery Right is an example for the devices Explanting the Device e The implant may become non functional either by accident or due to medical or technical reasons In this case it is strongly recommended to replace the device e If for any reason the device is not used anymore it is strongly recommended to explant the device If an explantation is not performed functional checks of Figure 46 X ray of CONCERTO Cl bilateral Courtesy of the implant on a regular basis are strongly University Clinic of Halle Saale ENT and Radiology recommended e If possible the device should be removed without damaging or cutting it Damage to the device during or after explantation may prevent or reduce the manufacturer s ability to determine the root cause of failure e Staff should follow common universal precautions and handle the explanted device as potentially contaminated biohazardous material e After explantation the implant should be appropriately cleaned and disinfected During cleaning extraneous tissue should be removed Dut only to such an extent that damage to the implant is not risked e Anexplanted device should be place
43. xed in a Mayfield clamp and rotated approximately 30 to the affected side This rotation Is necessary for a direct approach to the dorsal side of the petrous bone and in addition the opening of the lateral recess rotates towards the surgeon so that access is facilitated The reported advantage of this semi sitting position is an intraoperatively well balanced blood circulation in the body of the patient Therefore the blood pressure in the venous vessels of the head decreases which is advantageous to the surgical procedure It is also possible to perform this surgery with the patient in a horizontal position but it is not recommended here Intensive intraoperative monitoring is necessary during acoustic neuroma surgery and implantation of the ABI to control and protect nerve structures in and around the brainstem Cochlea vestibular VIII facial VII and caudal Cranial IX X nerve structures should be monitored during surgery Electrodes for measuring the nerve potentials are fixed on the patient before starting the surgery The anesthetist shall be familiar with the monitoring detection and management of air embolism and should also be familiar with anaesthetics connected with electrophysiological measurements The use of electrosurgery in ABI patients due to further tumor removal surgeries is likely If an electroscalpel is used in close proximity of the CONCERTO CONCERTO PIN ABI electrode the electrode could be damaged by
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