# Three-Dimensional Printing and Digital Flow in Human Medicine: A Review and State-of-the-Art
## 6 Experiences with the Use of 3D Technology in Medicine  
Currently, research in 3D printing has increased due to the impact on people's quality of life, the accuracy of 3D printed images and objects, the emergence of new printing materials, and the reduction in manufacturing costs [36; 37; 38]. It is used in medicine to improve patient communication, medical education, diagnosis, planning, and non-surgical or individualized surgical treatments, decreasing operative time and possible post-operative complications [39; 40; 41]. This signifies (at least in part) a new industrial revolution [1; 42]. In head and neck surgery, its main applications are placing implants using surgical guides, reconstructing lost facial structures or bone defects, and the simulation of surgical interventions [43]. In neurosurgery, in the case of aneurysms, it allows predetermining the size of the microcatheter to be used, as well as practicing clipping procedures to understand the vascular pathology preoperatively; planning electrode placement, based on anatomical models of the brain and skull; creating individualized and functional neurosurgical devices, such as the creation of compensators, to protect the organs surrounding the target tumor tissue during radiotherapy; printing 3D templates for the placement of pedicle screws with initial findings of no lesion incidence; and finally, it is currently used for trans-nasal spheroidal endoscopy to remove pituitary tumors [44]. Cardiology's leading application for congenital heart diseases is surgical planning using anatomical models [45]. In cardiovascular diseases, useful in case of severe aortic stenosis, where it is possible to replicate not only the anatomy but also the functional properties of aortic valve stenosis, for communication between the patient and the patient's \begin{table}
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Table 1: _Cont._relatives, with the medical team, besides facilitating teaching and the level of knowledge of residents [46], including [PERSON] et al., [47] in a systematic review indicated that education through 3D anatomical models is better than teaching through dissection of cadavers. In hepatopathies, anatomical models are of great utility; in addition, 3D images allow intraoperative guidance of procedures, such as hepatectomies of small tumors in infants; it will enable simulating of the placement of a stent during the transjugular intrahepatic portosystemic shunt (TIPS) procedure or the placement of a drain in percutaneous cholecystostomy [40]. In nephrology, it is used to replicate the complex anatomical structure of the kidney and its pathologies, which allows the visualization and planning of the surgical treatment, for example, in the intervention of renal tumors or transplants [48]. In the case of colorectal surgery, it is used to facilitate laparoscopic surgery; for example, in the case of 3D laparoscopic lymphadenectomy of right colon cancer, it has been shown that there were no intra or postoperative complications [39]. In anestesiology, airways have been replicated to plan and practice tracheal intubation techniques [49]. In pediatrics, the surgical treatment of cleft palate is an application of this technology, but also in non-surgical treatments, such as prosthetic rehabilitation in which the printing material plays a fundamental role [41]. In oncology, 3D printing, in addition to surgical procedures, is being applied in radiotherapy, bolus printing, and molds for brachytherapy [50; 51]. Bioprinting tissues and organs is another way of using this technology; thus, Celprogen Inc (California, USA) achieved the first 3D printed human heart and pancreas. Bioprinting of tissues and organs occurs because the three-dimensional structure of the print allows the vascularization of the tissue or organ by seeding with endothelial cells, using an extracellular matrix of proteins, and the isolation and differentiation of stem cells [11; 52].