Page 277 - Advances in Biomechanics and Tissue Regeneration

14.4 3D PRINTING OF PERSONALIZED SILICONE IMPLANT 275

In the medical field, silicone implants have been mainly used for the following applications [56–62]:

- Development of artificial organs (urethra, trachea, etc.)
- Restoration of organ or tissue functions (orthopedic implants, cardiac valves, cochlear implants, hydrocephalic
shunt, intralaryngeal implants, etc.)
- Reconstructive and aesthetic surgeries (breast, cheek, scrotum, orbital implant, and ORL implants)
- Development of disposable medical devices (contact lenses, catheters, etc.)

14.4.2 Silicone ORL Implant and the Need of Personalization
In this part, we will focus our discussion on the development of soft tissue facing implants in the otorhinolaryn-
gology field and more precisely in three specifics areas: the larynx, trachea, and bronchus. With these examples,
we aim to demonstrate the need, in some specific situations, to develop personalized implants that perfectly fit a given
patient’s anatomy. For this purpose, we will show how 3-D printing can facilitate the manufacture of personalized
implants.
In this area, one of the most common implants used are the stents. These devices are used to maintain the diameter
of lumen either in the trachea and larynx to prevent stenosis related to different pathologies to block the organ, that is,
respiration. These implants are directly implanted in the larynx or the trachea. Different kinds of stents can be used for
these purposes depending on the position of the stenosis: tracheal stents, larynx stents, or a combination of tracheal and
larynx stents. These stents are designed to be implanted for a limited period of time and are supposed to be removed at
the end. So, one of the specifications for these implants is the need of bio-inertness (no integration with the surrounding
tissues) meaning that cells and tissues should not adhere on the implant so that the removal of the implant will be
possible. Moreover, the implant should be noncytotoxic, transparent, and compatible with X-ray imaging techniques.
Silicone materials fulfill all these specifications such that they are available in medical grade, transparent, visible to
x-ray, and bio-inert, and its mechanical properties are similar to tissues that explain why most of the implants devel-
oped for such applications are made of silicone.
We will now give a brief explanation on the anatomy of this area and the related pathologies.
The laryngotracheobronchial tract constitutes the only “aerial tube” that allow the vital function of breathing
(Fig. 14.3).

FIG. 14.3 Laryngotracheobronchial tract.

II. MECHANOBIOLOGY AND TISSUE REGENERATION