[3D printing in plastic surgery, an accessible tool: Technical note around a case of otopoiesis assisted by 3D model]

3D printing has been used in the medical field since the beginning of the 21st century. Over the years, it has been democratized and has become an accessible tool at almost no cost, provided that a 3D printer is available. The surgeon can thus easily integrate it into his practice and techniques in the operating room, provided that he learns to use 3D image processing software. In order to illustrate the whole process, from the genesis and processing of the 3D image to its application in the operating room, we describe the case of a patient with a left auricle amputation, whose reconstruction was guided by a 3D model printed from his right ear.

[Comprehensive review of 3D printing use in medicine: Comparison with practical applications in urology]

INTRODUCTION

Over the past few years, 3D printing has evolved rapidly. This has resulted in an increasing number of scientific publications reporting on the medical use of 3D printing. These applications can range from patient information, preoperative planning, education, or 3D printing of patient-specific surgical implants. The objective of this review was to give an overview of the different applications in urology and other disciplines based on a selection of publications.

METHODS

In the current narrative review the Medline database was searched to identify all the related reports discussing the use of 3D printing in the medical field and more specifically in Urology. 3D printing applications were categorized so they could be searched more thoroughly within the Medline database.

RESULTS

Three-dimensional printing can help improve pre-operative patient information, anatomy and medical trainee education. The 3D printed models may assist the surgeon in preoperative planning or become patient-specific surgical simulation models. In urology, kidney cancer surgery is the most concerned by 3D printing-related publications, for preoperative planning, but also for surgical simulation and surgical training.

CONCLUSION

3D printing has already proven useful in many medical applications, including urology, for patient information, education, pre-operative planning and surgical simulation. All areas of urology are involved and represented in the literature. Larger randomized controlled studies will certainly allow 3D printing to benefit patients in routine clinical practice.

[Sterilisation of patient specific surgical guide for dental implantology made in a hospital: Validation of a sterility test and structural deformation study]

Medical device made to measure by 3D printing are now emerging in hospital. In order to improve the precision of surgery and facilitate the treatment of complicated cases, patient specific surgical guides for dental implantology are made by stereolithography in our facial surgical unit. This new activity requires to ensure the safety of patients and health personnel by validating the various step of the manufacturing circuit. In this context, the goal of this work was to study the quality of autoclave sterilisation of the patient specific surgical guide made to measure in our hospital. A protocol of sterility test was designed and validated. Sterility of implantology guides 0, 7, 14 and 28 days after sterilisation was checked. The impact of the autoclave sterilisation on the medical device structure was evaluated by visual check and during surgeries. The sterility of the implantology guides up to 28 days after sterilisation was also validated. The protocol of sterility test executed can be extended to other hospitals interested in validating a sterility test. No deformation was observed by surgeons during the dental implant process. Future studies may be necessary to check the accurate impact of sterilisation on surgical guide structure.

In-hospital professional production of patient-specific 3D-printed devices for hand and wrist rehabilitation

The reported use of 3D printing in hand and wrist rehabilitation has been mostly limited to feasibility studies and case series so far. Some of the reasons are the lack of purpose-built scanning applications, complicated digital design software, and lengthy and error-prone printing processes. We propose a multidisciplinary workflow for in-hospital mass production of patient-specific 3D-printed devices for hand and wrist rehabilitation.

3D printing in hand surgery

While 3D printing in hand surgery is still in its infancy, it offers new avenues in research, teaching, and personalized medicine. For these reasons, some surgeons may want to jump on the bandwagon of this trendy technology. But we cannot forget that its superiority over conventional techniques has not been demonstrated. Surgeons who want to work with 3D printed objects must master their use and the entire manufacturing process, otherwise they risk becoming dependent on engineers and/or medical device companies.

Role of cardiac imaging and three-dimensional printing in percutaneous appendage closure

Atrial fibrillation is the most frequent cardiac arrhythmia, affecting up to 13% of people aged>80 years, and is responsible for 15-20% of all ischaemic strokes. Left atrial appendage occlusion devices have been developed as an alternative approach to reduce the risk of stroke in patients for whom oral anticoagulation is contraindicated. The procedure can be technically demanding, and obtaining a complete left atrial appendage occlusion can be challenging. These observations have emphasized the importance of preprocedural planning, to optimize the accuracy and safety of the procedure. In this setting, a multimodality imaging approach, including three-dimensional imaging, is often used for preoperative assessment and procedural guidance. These imaging modalities, including transoesophageal echocardiography and multislice computed tomography, allow acquisition of a three-dimensional dataset that improves understanding of the cardiac anatomy; dedicated postprocessing software integrated into the clinical workflow can be used to generate a stereolithography file, which can be printed in a rubber-like material, seeking to replicate the myocardial tissue characteristics and mechanical properties of the left atrial appendage wall. The role of multimodality imaging and 3D printing technology offers a new field for implantation simulation, which may have a major impact on physician training and technique optimization.

[3D printing in health care facilities: What legislation in France?]

Health care facilities more and more use 3D printing, including making their own medical devices (MDs). However, production and marketing of MDs are regulated. The goal of our work was to clarify what is the current French regulation that should be applied concerning the production of custom-made MDs produced by 3D printing in a health care facility. MDs consist of all devices used for diagnosis, prevention, or treatment of diseases in patients. Prototypes and anatomic models are not considered as MDs and no specific laws apply to them. Cutting guides, splints, osteosynthesis plates or prosthesis are MDs. In order to become a MD manufacturer in France, a health care facility has to follow the requirements of the 93/42/CEE directive. In addition, custom-made 3D-printed MDs must follow the annex VIII of the directive. This needs the writing of a declaration of conformity and the respect of the essential requirements (proving that a MD is secure and conform to what is expected), the procedure has to be qualified, a risk analysis and a control of the biocompatibility of the material have to be fulfilled. The documents proving that these rules have been respected have to be available. Becoming a regulatory manufacturer of MD in France is possible for a health care facility but the specifications have to be respected.

[Reconstruction assisted by 3D printing in maxillofacial surgery]

INTRODUCTION

3-dimensional models (3D) appeared in the medical field 20 years ago. The recent development of consumer 3D printers explains the renewed interest in this technology. We describe the technical and practical modalities of this surgical tool, illustrated by concrete examples.

TECHNICAL NOTE

The OsiriX(®) software (version 5.8.5, Geneva, Switzerland) was used for 3D surface reconstruction of the area of interest, the generation and export of ".stl" file. The NetFabb(®) software (Basic version 5.1.1, Lupburg, Germany) provided the preparation of ".stl" file. The 3D-printer was an Up plus 2 Easy 120(®) (PP3DP, Beijing Technology Co. TierTime Ltd., Chine). The printer used fused deposition modeling. The softwar Up!(®) allowed the 3d impression as required.

RESULTS

The first case illustrated the value of 3D printing in the upper (frontal sinus and orbital roof). The second case concerned the preconfiguration of the osteosynthesis material for a complex fracture of the midface through the "mirroring" system. The third case showed the conformation of a prereconstruction for segmental mandibulectomy.

DISCUSSION

Current 3D-printers are easy to use and represent a promising solution for medical prototyping. The 3D printing will quickly become undeniable because of its advantages: information sharing, simulation, surgical guides, pedagogy.