*3.3.1 Other "alternative" approaches*

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 transattic approach [21].

#### **Figure 4.**

*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 incision with scalpel.*

**Figure 5.** *Modified periosteal flap for CI. Two flaps are taken: (A) anteriorly based flap and (I) inferiorly based flap.*

These alternative approaches aim at avoiding the risk of facial nerve injury and decreasing the duration of the surgical procedure. According to El-Anwar et al., there is no significant difference between the reported overall complications rate using either the classic or alternative approaches for CI [22]. However, many authors discourage the non-mastoidectomy approaches for cochlear implantation for the following reasons: First, the angle between the electrode array and the trajectory line of the cochlea is more than 30°; this makes electrode insertion difficult with increasing possibility of intracochlear kinking of the electrode or intracochlear trauma [23]. Second, fixation of the electrode array into a tunnel or groove in the EAC is not suitable for children due to continuous EAC growth [19]. Third, alternative approaches have higher rate of revision cases on the long-term follow-up [11].

Most of the surgeons nowadays use the standard MPTA for CI; the nontraditional approaches for CI are used in extremely rare cases with difficult anatomical situations [22].

#### *3.3.2 Robotic surgery in cochlear implantation*

The beginning of the idea of "robotic cochlear implantation" was by thinking in using the navigation system in cochlear implantation through a computerassisted CI surgery using the same classic posterior tympanotomy approach. This idea was first introduced and tried first on cadaver dissection in 2004 [24]; then in 2009, Majdani et al. [25] performed a cadaveric study of using a combination of industrial robot system and navigation system for building a "closed-loop feedback" control system for CI. Through this system they could make real-time feedback to track any movement or changes in the bone based on a preoperative temporal bone CT scan. Vital structures, such as the facial nerve, were defined and protected. The robot was able to drill only the targeted bone without violation of any critical structures [25].

After extensive work and experimental trials for inventing accurate combined robotic and image-guided system for CI [26–28], the minimally invasive robotic percutaneous cochlear implantation (PCI) became real [29].

PCI can modify the classic MPTA into drilling a predesigned small single straight bony tunnel starting from the mastoid cortex and targeting into the RW without risk of injury of the facial nerve, chorda tympani, external auditory canal, and tympanic membrane annulus [30].

**127**

*Advances in Surgical and Anesthetic Techniques for Cochlear Implantation*

According to the first reported case of robotic PCI [29], the procedure starts

1.It is a minimal invasive surgery with small wound, short duration, and minimal bone drilling which can cause noise and thermal effect on the cochlea.

2.It has high accuracy rates; the geometric accuracy was measured, in experimental studies, equal to 0.15 ± 0.08 mm at the depth of the cochlea.

3.It preserves the mastoid air cells, which has physiological role in middle ear

The trends in manufacturing recent CI devices is toward making the RS as thin as possible, so that recent devices are thinner and need drilling a shallower bony well for RS. For example, the thickness of the RS of the CI532® (Cochlear Corp) is 3.9 mm, while the thickness of the RS of the older generation of the same company such as CI124RE® is 6.9 mm. Drilling a bony well with depth equal to 3 mm is usu-

Some surgeons advocate the tight "temporalis pocket" technique in fixating the body of the implant; this technique entails elevation of small tight periosteal pocket that can just lodge the device tightly without the need of drilling a well for the RS [31]. Although slim devices can be fixed easier with tight temporalis pocket technique, still most of surgeons prefer drilling a well for stabilization of the RS [16].

• Tie-down sutures that were passed through monocortically drilled holes on

• Using polypropylene mesh over the R/S and securing the mesh with titanium

2.Its safety and accuracy in vivo are still under clinical trials.

ally enough to accommodate most of recent implants.

• Cementing the R/S with ionomeric bone cement [34].

by preoperative imaging and accurate planning of the drilling pathway and identification of vital structures, before surgery. Then intraoperatively the drill path was assessed using imaging- and sensor-based data to confirm the proximity of the facial nerve. After making the bony tunnel with the robot, a small postauricular incision is made to elevate tympanomeatal flap to expose the RW membrane. The RW membrane is opened through anterior tympanotomy after elevation of the tympanomeatal flap, and then the electrode array, passing through the drilled tunnel, was inserted manually under microscope visualiza-

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

*3.3.3 Technique of robotic PCI*

*3.3.4 Advantage of robotic PCI*

ventilation.

1.Expensive.

*3.3.5 Disadvantage of robotic PCI*

**3.4 Drilling a bony well for the RS**

Other methods for RS fixation:

each side of the R/S [32].

screws [33].

tion [29].
