**7.2 Alpha 2 (www.sophono.com)**

The Alpha 2 by Sophono is another bone-anchored prosthesis without percutaneous screw and consists of a processor that is coupled to the skin transcutaneously with a titanium component implanted subcutaneously, containing two magnets.

#### **Figure 10.**

*(A) BAHI model is placed on the skin exactly in the area where it will be placed. After considering the distance from the superior margin of the external auditory canal, a point is deigned on the skin as landmark***.** *A meter is used to measure the distance from the external auditory canal where the BAHI that is approximately 50–55 mm is placed. This distance is necessary to avoid the prosthesis from touching the pinna. (B) A line parallel to the point previously identified is then designed in the skin of the retro-auricular area. (C) After using the BAHI model for designing the location of the implant, a blue mytilene solution is injected for delineating on the mastoid bone the lodgment of the implant.*

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**Figure 13.**

**Figure 12.**

**Figure 11.**

*Congenital Aural Atresia: Hearing Rehabilitation by Bone-Anchored Hearing Implant (BAHI)*

*(A) By using a dermographic pen, the incision line is designed on the skin. (B) After surgical incision the lodgment for the bone anchorage is performed by using a drill. (C) The anchorage after the skin closure with head in vertical position. Final result. Live surgery: https://www.youtube.com/watch?v=Pz2qZxzkV1I.*

The magnetic attraction allows to hold the processor in place and to transmit acoustic energy [31]. The limits of this kind of device are represented by energy loss through the skin layer and possible discomfort and complications due to soft

*(A) BAHI is placed and fixed with titanium screw. (B) Continuous cutaneous suture to guarantee sterility. Live surgery traditional method: https://www.youtube.com/watch?v=AagsHvgsmDs. Live surgery simplified* 

*(A) Musculocutaneous flap with exposure of mastoid (B) using a cutting burr creation of lodgment area.*

**7.3 Bonebridge (https://www.medel.com/hearing-solutions/bonebridge)**

The Bonebridge by MED-EL is a semi-implantable bone conduction auditory system comprising a processor that is coupled transcutaneously to a titanium component and silicone implanted subcutaneously. The transducer, lodged in the

tissue pressure [21] (**Figures 12** and **13**).

*method: https://www.youtube.com/watch?v=gJM1jt8W\_rI.*

*DOI: http://dx.doi.org/10.5772/intechopen.88201*

*Congenital Aural Atresia: Hearing Rehabilitation by Bone-Anchored Hearing Implant (BAHI) DOI: http://dx.doi.org/10.5772/intechopen.88201*

#### **Figure 11.**

*Advances in Rehabilitation of Hearing Loss*

structures [30].

**oticonmedical.com/it)**

**7.2 Alpha 2 (www.sophono.com)**

*mastoid bone the lodgment of the implant.*

See **Figures 10** and **11.**

**7. Surgical method of implant and timing**

before 5 years by using an elastic band (Softband).

The FDA recommends to apply the device in children not younger than 5 years.

Authors say that the ideal age for implanting a BAHI is between 2 and 4 years, because at this age the thickness of retromastoid bone (2.5–3 mm) allows to perform a totally safe surgery, without risk of damaging the dura. Additionally, regarding the age of implant, we have to consider that children need to possess a sufficient manual dexterity to maintain the device and a good psychological tendency to follow the suggestions of parents and caregivers. We usually correct hearing aids

The Tjellström et al. technique, proposed in 1977, suggest the creation of a thin muscle-cutaneous flap. The main disadvantage is an altered vascularization that may lead to infection and wound healing problems, dysesthesia in the retroauricular area and alopecia. For solving these problems, a less invasive technique by using a linear retro-auricular incision has been proposed and currently is the mostly used. The main benefit of this new technique is the good preservation of the vascularization in the surgical area that allows to avoid all the problems of muscle-cutaneous flap (infection, healing problems, dysesthesia, etc.). Another suggested low invasive technique is based on the removal of a very small piece of skin in the area in which the titanium implant should be placed. The skin removed has the same dimension of a biopsy. This technique also presents the advantages of the liner incision, due to the reduced trauma on tissue and vascular

**7.1 BAHA®(https://www.cochlear.com/it/home) and PONTO® (https://www.**

The Alpha 2 by Sophono is another bone-anchored prosthesis without percutaneous screw and consists of a processor that is coupled to the skin transcutaneously with a titanium component implanted subcutaneously, containing two magnets.

*(A) BAHI model is placed on the skin exactly in the area where it will be placed. After considering the distance from the superior margin of the external auditory canal, a point is deigned on the skin as landmark***.** *A meter is used to measure the distance from the external auditory canal where the BAHI that is approximately 50–55 mm is placed. This distance is necessary to avoid the prosthesis from touching the pinna. (B) A line parallel to the point previously identified is then designed in the skin of the retro-auricular area. (C) After using the BAHI model for designing the location of the implant, a blue mytilene solution is injected for delineating on the* 

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**Figure 10.**

*(A) By using a dermographic pen, the incision line is designed on the skin. (B) After surgical incision the lodgment for the bone anchorage is performed by using a drill. (C) The anchorage after the skin closure with head in vertical position. Final result. Live surgery: https://www.youtube.com/watch?v=Pz2qZxzkV1I.*

#### **Figure 12.**

*(A) Musculocutaneous flap with exposure of mastoid (B) using a cutting burr creation of lodgment area.*

#### **Figure 13.**

*(A) BAHI is placed and fixed with titanium screw. (B) Continuous cutaneous suture to guarantee sterility. Live surgery traditional method: https://www.youtube.com/watch?v=AagsHvgsmDs. Live surgery simplified method: https://www.youtube.com/watch?v=gJM1jt8W\_rI.*

The magnetic attraction allows to hold the processor in place and to transmit acoustic energy [31]. The limits of this kind of device are represented by energy loss through the skin layer and possible discomfort and complications due to soft tissue pressure [21] (**Figures 12** and **13**).

#### **7.3 Bonebridge (https://www.medel.com/hearing-solutions/bonebridge)**

The Bonebridge by MED-EL is a semi-implantable bone conduction auditory system comprising a processor that is coupled transcutaneously to a titanium component and silicone implanted subcutaneously. The transducer, lodged in the mastoid bone, transmits mechanical vibrations directly to the inner ear jumping middle and outer ear. The conduction system is light (∼10 g), and it has an area of ∼8.7 mm (height) × 15.8 mm (diameter). Two titanium screws—responsible for the vibrations transduced to the system—are located to a distance of around 24 mm between them.

Bonebridge is the unique BAHI with active mechanism; the information analyzed by the audio-processor are sent to the antenna and transmitted through the skin to the system. It converts the received signals into mechanical vibrations, which are transmitted to the inner ear by bone conduction. The transductor is surgically positioned at the seno-dural angle. However, due to its slightly bulky internal implant, the most optimal location for placing BB implant should be carefully selected preoperatively using 3D reconstruction software [32].

As compared to percutaneous BCI, Bonebridge's transcutaneous technology enables the avoidance of several complications including skin reaction, growth of skin over the abutment, implant extrusion, and wound infection.

BB presents the same risks of the other BAHIs (skin infection and skin necrosis), and currently nobody described severe complications by using this implant. We suggest to use a double flap for minimizing the skin trauma and improving the outcomes (**Figures 14** and **15**).

#### **Figure 14.**

*(A) Measurement of temporal bone thickness before surgery and (B) lodgment for BAHI created posteriorly to the pinna.*

#### **Figure 15.**

*(A) After lodged BAHI is fixed to the temporal bone with a screw and (B) way in which the implant appears before the closure of the skin. Live surgery: https://www.youtube.com/watch?v=Wlh6YxEnJl8.*

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*Congenital Aural Atresia: Hearing Rehabilitation by Bone-Anchored Hearing Implant (BAHI)*

We widely use BAHIs both in the case of aural atresia (singular or bilateral form) [1, 15, 21] and as treatment of single side deafness [1], and our results are supported

We observed that BAHI not only improved the hearing abilities of children in noise condition but also their dictation capacity during the school activity [1, 15, 21]. We compared children wearing BAHI immediately after the implant and then 3 months later they were implanted, and we noticed that their abilities in speech perception increased time by time by reaching the same scores observed in healthy children after 3 months [1]. In addition, we analyzed the short and working memory abilities in children with BAHI, before and after implantation, and we identified that both these memory functions improved by restoring the hearing with BAHIs. The memory abilities, as the speech perception done, increased time by time by overlapping the score obtained by healthy children in the same age range [1]. Finally, we observed that children after being implanted with BAHI improved their school scores and increased their relationship with friend and environment [21]. Reported complications are slight skin problems as localized irritation and hypertropic scare around the titanium implant. The skin inflammation may be explained as an immune answer to an external body (the screw). In the literature the rates go from 5 to 7.5% for skin regrowth and from 1.3–10% for extrusion of the

We think that BAHIs are a very good solution for restoring hearing abilities. Although we have a wide experience on children, due to the excellent results

obtained on these patients, in terms of speech discrimination but much more for the impressive benefit obtained in memory function, we suggest BAHIs as treatment of

As we have shown in our chapter, BAHIs are simple to implant, with very low side effects, and their surgery is poor and time-consuming. We speculate that due to the new theories on BAHIs' stimulation of the inner ear [33–37], these implants could be a valid alternative to the traditional hearing aids in slight-mild form of asymmetric hearing loss; we suggest BAHIs not only in the case of conductive hear-

*DOI: http://dx.doi.org/10.5772/intechopen.88201*

by other authors' observations [16–19, 29, 30].

**8. Our results**

abutment [15].

**9. Conclusions**

**Conflict of interest**

hearing loss in adults' population too.

ing loss (CHL) but also in the sensorineural form (SNHL).

The authors declare no conflict of interest.

*Congenital Aural Atresia: Hearing Rehabilitation by Bone-Anchored Hearing Implant (BAHI) DOI: http://dx.doi.org/10.5772/intechopen.88201*
