Reverse Engineering and Additive Manufacturing-based tools for autologous ear reconstruction

The advent and the consolidation of Reverse Engineering (RE) and Additive Manufacturing (AM) techniques in the medical field changed significantly the common therapeutic and surgical approach, pushing towards a new perspective of treatment in which each patient is considered unique. The integration of RE e AM techniques enables the modeling and realization of customized medical devices: RE techniques allow to acquire and reconstruct the patient-specific anatomy, AM processes make possible to create any geometric shape, that could not be realized with traditional production techniques. In the field of plastic surgery, is observed a wide use of such techniques for the production of patient-specific implants and patient-specific surgical guides. Reconstructive surgery is, in fact, a challenge even for the most experienced surgeons due to the complex anatomy involved and the uniqueness of defects and malformations; the use of medical devices which accurately fit the anatomy of the defect, has demonstrated to improve surgical outcomes in terms of aesthetic results, of surgical time and safety for the patients. In this context, the present thesis focuses on the development and design of tools able to support the surgeon in the reconstruction of the external ear. Such reconstructive intervention is performed in patients affected by deformation or absence of the external ear due to congenital reasons (microtia), as a result of trauma, burns or tumor resections. The intervention is considered among the surgeons particularly complex and the surgical outcomes are highly dependent on the experience of clinicians. For such reasons, my research thesis initially focused on the study of methods and tools for the simulation, planning and execution of the intervention with the aim to improve the performance of experienced surgeons and to make this intervention accessible to a wider range of physicians. From a close collaboration with the plastic surgeons of the Meyer Children's Hospital (Florence, Italy), arose the idea of new surgical guides for preoperative simulation and surgery. Technical and clinical requirements of surgical guides were identified by physicians and through a trial phase, that foresaw CAD modeling by engineers and testing by surgeons, the final design of the devices was defined. Secondly, with the idea of making physicians independent of experienced CAD modelers in the manufacturing process of such instruments, a systematic procedure was defined that starts from the patient's anatomy data and leads to 3D modeling of the devices. The procedure was semi-automated and made easily accessible to surgeons through an intuitive graphical user interface that allows them to be independent in the creation of each new device. The aim is to introduce a new tool in the common clinical practice, suitable for use in a hospital environment, which pushes towards a new concept of personalized assistance.