Clinical Applications of Additive Manufacturing Models in Neurosurgery: a Systematic Review

Introduction Three-dimensional (3D) printing technologies provide a practical and anatomical way to reproduce precise tailored-made models of the patients and of the diseases. Those models can allow surgical planning, besides training and surgical simulation in the treatment of neurosurgical diseases. Objective The aim of the present article is to review the scenario of the development of different types of available 3D printing technologies, the processes involved in the creation of biomodels, and the application of those advances in the neurosurgical field. Methods We searched for papers that addressed the clinical application of 3D printing in neurosurgery on the PubMed, Ebsco, Web of Science, Scopus, and Science Direct databases. All papers related to the use of any additivemanufacturing technique were included in the present study. Results Studies involving 3D printing in neurosurgery are concentrated on threemain areas: (1) creation of anatomical tailored-made models for planning and training; (2) development of devices and materials for the treatment of neurosurgical diseases, and (3) biological implants for tissues engineering. Biomodels are extremely useful in several branches of neurosurgery, and their use in spinal, cerebrovascular, endovascular, neuro-oncological, neuropediatric, and functional surgeries can be highlighted. Conclusions Three-dimensional printing technologies are an exclusive way for direct replication of specific pathologies of the patient. It can identify the anatomical variation and provide a way for rapid construction of training models, allowing the medical resident and the experienced neurosurgeon to practice the surgical steps before the operation.

Uso de digitalizador e impressora doméstica em 3 dimensões em rinoplastia / Domestic three-dimensional scanner and printer in patients undergoing rhinoplasty

Os princípios para uma rinoplastia bem-sucedida incluem consulta e planejamento pré-operatório e uma análise clínica abrangente que defina as metas da cirurgia. Mais recentemente, a digitalização e a impressão doméstica em 3 dimensões tornaram-se disponíveis. O objetivo deste estudo é descrever um método de digitalização em 3 dimensões e de impressão doméstica da anatomia real do paciente para ser usada como ajuda intraoperatória. Nós apresentamos uma forma de uso desta tecnologia no transoperatório, auxiliando o cirurgião a comparar os resultados obtidos após suas manobras, verificar a sua adesão ao plano cirúrgico previamente estabelecido e melhorar a sua tomada de decisão durante a cirurgia. Em conclusão, a aplicação da impressão doméstica em 3 dimensões demonstra um efeito positivo sobre o tratamento de alterações estéticas do nariz.

The principles for a successful rhinoplasty include preoperative consultation and planning, as well as a comprehensive clinical analysis and defining rhinoplasty goals. Three-dimensional domestic scanning and printing have recently become available. We sought to objectively describe this method as an intraoperative aid in patients' anatomy. This method can be used trans-operatively to help surgeons compare the results of his or her technique, check adherence to the surgical plan, and improve his or her surgical decision-making. We found that the application of 3-dimensional printing had a positive effect on the treatment of patients with aesthetic nose disorders.

Optimization and comparison of two different 3D culture methods to prepare cell aggregates as a bioink for organ printing

The ultimate goal of tissue engineering is to design and fabricate functional human tissues that are similar to natural cells and are capable of regeneration. Preparation of cell aggregates is one of the important steps in 3D tissue engineering technology, particularly in organ printing. Two simple methods, hanging drop (HD) and conical tube (CT) were utilized to prepare cell aggregates. The size and viability of the aggregates obtained at different initial cell densities and pre-culture duration were compared. The proliferative ability of the cell aggregates and their ability to spread in culture plates were also investigated. In both methods, the optimum average size of the aggregates was less than 500 µm. CT aggregates were smaller than HD aggregates. 5,000 cells per drop HD aggregates showed a marked ability to attach and spread on the culture surface. The proliferative ability reduced when the initial cell density was increased. Comparing these methods, we found that the HD method having better size controlling ability as well as enhanced ability to maintain higher rates of viability, spreading, and proliferation. In conclusion, smaller HD aggregates might be a suitable choice as building blocks for making bioink particles in bioprinting technique.