Validation of design and materials for additive manufacturing of endocavitary mechanical distractor.

Purpose: This paper describes the evolution of the design of a mechanical distractor fabricated using additive manufacturing (AM) technology for use in surgical procedures, such as transanal endoscopic microsurgery (TEM). The functionality of the final device was analysed and the suitability of different materials was determined. Design/methodology/approach: Solid modelling and finite element modelling software were used in the design and validation process to allow the fabrication of the device by AM. Several prototypes were manufactured and tested in this study. Findings: A new design was developed to greatly simplify the existing devices used in TEM surgery. The new design is easy to use, more economical and does not require pneumorectum. Different AM materials were investigated with regard to their mechanical properties, orientation of parts in the three-dimensional (3D) printer and cytotoxicity to select the optimal material for the design. Social implications: The device designed by AM can be printed anywhere in the world, provided that a 3D printer is available; the 3D printer does not have to be a high-performance printer. This makes surgery more accessible, particularly in low-income regions. Moreover, patient recovery is improved and pneumorectum is not required. Originality/value: A suitable mechanical distractor was designed for TEM, and different materials were validated for fabrication by AM. [ABSTRACT FROM AUTHOR]