**2.7 Confirm device fixation**

The RS should be positioned in its drilled well "Seat or bed." Its stability in the well should be ensured. Sewing the periosteum together over the implant is also important for further stabilization [7].

The distal end of the electrode array should be secured and fixed. This is performed routinely by sealing off the cochleostomy site through harvesting a small piece of fascia or pericranium and then applying it around the electrode array at the cochleostomy site. This sealing also prevents transmission of infection from the middle ear into the cochlea [6]. Also the electrode array is further stabilized by placing a loop of electrode cable against the tegmen mastoideum [8].

#### **2.8 Intraoperative monitoring**

Intraoperative device monitoring is performed to confirm both electrical output of the device and electrical response of the patient at the same time. Intraoperative monitoring also provides objective data that can be used as a starting point for behavioral testing "psychophysics" [9].

First impedance telemetry, which confirms the integrity of the electrodes, is performed to all electrodes, and then the neural response of the patient can be tested by either measuring the electrical stapedial reflex thresholds (ESRT) or by measuring electrical compound action potential (ECAP), or neural response telemetry (NRT), which confirms stimulation of the auditory nerve. These electrical tests are essential to confirm the success of surgery; however, they are not a reliable predictor of postoperative performance [10].

#### **2.9 Wound closure**

The wound is closed in three layers: the periosteum, the subcutaneous layer, and the skin. Usually the dressing and pressure bandage are kept for 24 hours to reduce the possibility of a development of seroma or hematoma, then the wound is inspected, and another dressing is applied for another 5 days [5].

## **3. Advances of the surgical technique**

Surgical technique of cochlear implantation was described in detail by House [3]; this description remains the classic or the standard surgical technique for cochlear implantation. Up till the time of writing of these words, there is no significant change in the basic surgical principles of the classic or standard CI. However, some surgical modifications and technical innovations were advanced and advocated by some surgeons. The most important surgical advances on the classic CI, according to our point of view, are listed in this section and sorted according to the consequence of surgical steps of CI.

#### **3.1 Skin incision**

The first described incision for CI was small postauricular C-shaped incision as the device has a single channel and is small in size, and then after inventing the multichannel devices, which had larger RS, larger postauricular C-shaped incisions or interior-based U-shaped incision were used. Due to the drawback of these large incisions on the blood supply with high incidence of flap necrosis, postauricular incision became the standard again and remained the most commonly used incision [4]. It was first long with an upward extension "inverted J-shaped incision" and then gradually become shortened by time. Nowadays many CI centers use the minimal access postauricular incision (**Figure 1**), which is 3–4 cm in length and 1 cm behind the postauricular crease [11].

An extended endaural incision has been described as an alternative incision [12]. This incision aimed at making the skin incision away from the tension that may be caused by the body of the implant and the RS; however, skin breakdown at the

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**Figure 4.**

*incision with scalpel.*

*Advances in Surgical and Anesthetic Techniques for Cochlear Implantation*

external auditory canal (EAC) and wound infection have been reported as compli-

Few modifications of the standard anterior-based periosteal flap "Palva flap" in CI were described; the aim of these modifications is to ensure both good exposure of the drilling areas (mastoid bone and RS well) and tight periosteal covering of the device at the same time. One of these modifications was described by Fouad et al. [15] in which the periosteum is elevated through two flaps: the first flap is a short anteriorly based periosteal flap that aims at exposure of the mastoid bone, and the second flap is an inferiorly based flap that aims at exposure of the RS bony well (**Figure 5**). Through this modification, the periosteum can cover the device completely without tension, and mastoid emissary vein disruption could

For more than half a century, the MPTA remains the gold standard approach for CI [16]. However, there is still need for "alternative" approach in certain situations. Also robotic CI is a new invention that can be used to reduce the need for excess bone drilling and to gain more rapid, safe, and direct access to the RW membrane.

MPTA is the classic standard approach for CI [17]. Many alternative approaches were described for CI. The most common are the suprameatal

approach [18], the pericanal approach [19], transcanal (Veria) approach [20], and

*Modified endaural incision for CI. (a) Incision marking on the skin (note the transverse part of the incision is at the junction between the conchal cartilage and EAC cartilage) and (b) cutting the transverse part of the* 

**3.3 Mastoidectomy posterior tympanotomy approach**

The surgical technique of endaural incision in CI should differ from the standard technique used for other otologic surgeries; the standard endaural incision entails incising the skin and periosteum in the same incision line at the incisura and the bony cartilaginous junction of the EAC. Endaural incision for cochlear implantation should be modified. The skin only is incised at the incisura and at the intercartilaginous gap between the conchal cartilage and EAC cartilages (**Figure 4**), then the skin and the SC tissues are dissected from the underlying pericranium, and then the pericranium is incised away from the site of skin incision. We think that through this modification, endaural incision can be used in CI with lower risk of wound

*DOI: http://dx.doi.org/10.5772/intechopen.88380*

cations of this incision [11, 13, 14].

infection or skin breakdown.

**3.2 Periosteal flap elevation**

*3.3.1 Other "alternative" approaches*

transattic approach [21].

be avoided [15].

*Advances in Surgical and Anesthetic Techniques for Cochlear Implantation DOI: http://dx.doi.org/10.5772/intechopen.88380*

external auditory canal (EAC) and wound infection have been reported as complications of this incision [11, 13, 14].

The surgical technique of endaural incision in CI should differ from the standard technique used for other otologic surgeries; the standard endaural incision entails incising the skin and periosteum in the same incision line at the incisura and the bony cartilaginous junction of the EAC. Endaural incision for cochlear implantation should be modified. The skin only is incised at the incisura and at the intercartilaginous gap between the conchal cartilage and EAC cartilages (**Figure 4**), then the skin and the SC tissues are dissected from the underlying pericranium, and then the pericranium is incised away from the site of skin incision. We think that through this modification, endaural incision can be used in CI with lower risk of wound infection or skin breakdown.
