**2. Material and methods**

All selected candidates were implanted with the Esteem® AMEI. Potential candidates were selected after a thorough audiometric assessment, which included pure tone and speech audiometry. In accordance with the Envoy Medical data, the advised threshold range is that reported in **Figure 3**, with a speech discrimination score better than 40%.

Once the audiological clearance is given, a preliminary CT scan of the petrous bone is carried out to assess the feasibility of the procedure, in particular, if the space inside the mastoid cavity would be sufficient for housing the two transducers: the sensor on the incus body, by measuring the distance between the incus body and the sino-dural angle, and the driver on the stapes head, through a wide posterior tympanotomy, going posteriorly toward the sigmoid sinus region and lateral to the mastoid facial nerve course. At this point, all the information regarding use, time of use, and performances with a cHA is taken and thoroughly evaluated by speech audiometry in quiet and noise as well as by specific questionnaires.

The surgical procedure is performed under general anesthesia, with facial nerve monitoring and under hypotensive control all along the surgical steps, especially when cementing is taking place. The main steps of the surgical procedure are summarized as follows:


**95**

*The Esteem®, Fully Implantable Middle Ear Device DOI: http://dx.doi.org/10.5772/intechopen.89250*

joint.

4.Posterior epitympanectomy is then carried out until getting the complete exposure of the incus body and the malleus head, with the incudomalleolar

5.Posterior tympanotomy is then drilled, thinning out—but keeping intact—the posterior buttress; drilling is continued until a gross trapezoidal-shaped opening is obtained at the expense of the chorda tympani nerve, which needs to be severed in all cases to avoid its eventual contact with the driver transducer. The lateral aspect of the posterior tympanotomy will correspond to the fibrous tympanic annulus. The superior corner of the posterior tympanotomy is drilled until obtaining an acute angle. The whole long process of the incus and the

6.After placing a soft insert microphone—connected to a laser Doppler vibrometer (LDV) System—into the external auditory canal, two small reflectors are placed on the incus body and on the posterior crus of stapes for allowing the assessment of the normal mobility of the intact ossicular chain [4]. LDV, mounted on a second microscope, checks first the intact chain movement, which should mandatorily give normal values before continuing the procedure. LDV is a very accurate (G1 10 j4 Km), noncontact instrument that works by comparing the frequency of the emitted laser diode light with the frequency of the reflected light of the moving object (**Figure 4**). Sound at 100-dB SPL and a sweep of 50

7.Separation of the incudostapedial joint is performed after gently removing the

9.At this point, removal by scraping of the mucosa over the stapes head is accomplished after dying the area with methylene blue, and finally drying it with

10. A drop of EnvoyCem® (a bioglass type of biological cement) is then applied on

11.Both sensor and drivers transducers are then attached to the Glasscock stabilizers screwed on the posterior edge of the mastoidectomy cavity and are then placed on the incus body and on the precoated stapes head, respectively.

12.MedCem® (an hydroxyapatite type of biological cement) is then composed and syringed into the mastoidectomy cavity for keeping and permanently fix-

13. A small drop of EnvoyCem® is then placed to cement the tip of the driver on the precoated stapes capitulum, as well as between the sensor tip and the incus body, followed by creation of a new joint (detachment of the cemented sensor

14.Laser Doppler vibrometer (LDV) measurements are then performed, for test-

pyramidal eminence needs to be optimally visualized.

frequencies ranging from 125 to 8.000 Hz are used.

the stapes head, so that a "precoat" is obtained.

ing the transducers' bodies in place.

ing both sensor and driver efficiency.

tip from the incus body).

8.By diode laser, then, part of the long incus process is sectioned.

overlying mucosa.

low-watt laser beam.

*The audiometric range of indication for the Esteem® fully implantable hearing device.*

*Advances in Rehabilitation of Hearing Loss*

All selected candidates were implanted with the Esteem® AMEI. Potential candidates were selected after a thorough audiometric assessment, which included pure tone and speech audiometry. In accordance with the Envoy Medical data, the advised threshold range is that reported in **Figure 3**, with a speech discrimination

Once the audiological clearance is given, a preliminary CT scan of the petrous bone is carried out to assess the feasibility of the procedure, in particular, if the space inside the mastoid cavity would be sufficient for housing the two transducers: the sensor on the incus body, by measuring the distance between the incus body and the sino-dural angle, and the driver on the stapes head, through a wide posterior tympanotomy, going posteriorly toward the sigmoid sinus region and lateral to the mastoid facial nerve course. At this point, all the information regarding use, time of use, and performances with a cHA is taken and thoroughly evaluated by speech

The surgical procedure is performed under general anesthesia, with facial nerve monitoring and under hypotensive control all along the surgical steps, especially when cementing is taking place. The main steps of the surgical procedure are sum-

1.Identification of a flat, retro-auricular area in which a bony niche for the sound processor (SP) can be drilled. Accordingly, the skin incision is outlined and

2.A lazy-C retro-auricular incision, including skin and subcutaneous tissue, is carried out. After placement of self-retaining retractors, a large Palva flap is created and elevated with an anteriorly based pedicle. The SP bone well is then drilled by using large (6–8 mm) cutting and diamond burs, ending up by drilling two small holes on both sides for securing the SP to the skull at the end of

3.An enlarged mastoidectomy is then drilled, completely exposing the presigmoid area, the sino-dural angle, and the inferior mastoid cell tip area.

*The audiometric range of indication for the Esteem® fully implantable hearing device.*

audiometry in quiet and noise as well as by specific questionnaires.

injected with vasoconstrictor solution.

surgery by nylon thread.

**2. Material and methods**

score better than 40%.

marized as follows:

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**Figure 3.**


**Figure 4.**

*Normative data regarding displacement of the incus (left) and stapes (right) when measured by laser Doppler vibrometry.*

15.The SP is then put in place and attached to the sensor and driver cables. Final LDV measurements of the whole system are then carried out and precede the end of surgery with a three-layer closure.

A bandage is then wrapped around the head and kept for 24 h. The implant is activated approximately 2 months after surgery, with the first fitting session, and later upgraded every 3 months during the first postoperative year.

Once required, the SP will be substituted via a minor surgical procedure, oftentimes performed under local anesthesia. The procedure entails a C-shaped, 5-cm long skin incision behind the SP that is subsequently exposed to allow first the disconnection from the cables of the two transducers, then their reconnection to the new SP.
