A plastic surgery application in evolution: three-dimensional printing. Plast Reconstr Surg. 2014;133:446-451. [PMID: 24469175 DOI: 10.1097/01.prs.0000436844.92623.d3]

Emerging Applications of Bedside 3D Printing in Plastic Surgery

Modern imaging techniques are an essential component of preoperative planning in plastic and reconstructive surgery. However, conventional modalities, including three-dimensional (3D) reconstructions, are limited by their representation on 2D workstations. 3D printing, also known as rapid prototyping or additive manufacturing, was once the province of industry to fabricate models from a computer-aided design (CAD) in a layer-by-layer manner. The early adopters in clinical practice have embraced the medical imaging-guided 3D-printed biomodels for their ability to provide tactile feedback and a superior appreciation of visuospatial relationship between anatomical structures. With increasing accessibility, investigators are able to convert standard imaging data into a CAD file using various 3D reconstruction softwares and ultimately fabricate 3D models using 3D printing techniques, such as stereolithography, multijet modeling, selective laser sintering, binder jet technique, and fused deposition modeling. However, many clinicians have questioned whether the cost-to-benefit ratio justifies its ongoing use. The cost and size of 3D printers have rapidly decreased over the past decade in parallel with the expiration of key 3D printing patents. Significant improvements in clinical imaging and user-friendly 3D software have permitted computer-aided 3D modeling of anatomical structures and implants without outsourcing in many cases. These developments offer immense potential for the application of 3D printing at the bedside for a variety of clinical applications. In this review, existing uses of 3D printing in plastic surgery practice spanning the spectrum from templates for facial transplantation surgery through to the formation of bespoke craniofacial implants to optimize post-operative esthetics are described. Furthermore, we discuss the potential of 3D printing to become an essential office-based tool in plastic surgery to assist in preoperative planning, developing intraoperative guidance tools, teaching patients and surgical trainees, and producing patient-specific prosthetics in everyday surgical practice.

3D printing of intracranial artery stenosis based on the source images of magnetic resonance angiograph

BACKGROUND AND PURPOSE

Three dimensional (3D) printing techniques for brain diseases have not been widely studied. We attempted to 'print' the segments of intracranial arteries based on magnetic resonance imaging.

METHODS

Three dimensional magnetic resonance angiography (MRA) was performed on two patients with middle cerebral artery (MCA) stenosis. Using scale-adaptive vascular modeling, 3D vascular models were constructed from the MRA source images. The magnified (ten times) regions of interest (ROI) of the stenotic segments were selected and fabricated by a 3D printer with a resolution of 30 µm. A survey to 8 clinicians was performed to evaluate the accuracy of 3D printing results as compared with MRA findings (4 grades, grade 1: consistent with MRA and provide additional visual information; grade 2: consistent with MRA; grade 3: not consistent with MRA; grade 4: not consistent with MRA and provide probable misleading information). If a 3D printing vessel segment was ideally matched to the MRA findings (grade 2 or 1), a successful 3D printing was defined.

RESULTS

Seven responders marked "grade 1" to 3D printing results, while one marked "grade 4". Therefore, 87.5% of the clinicians considered the 3D printing were successful.

CONCLUSIONS

Our pilot study confirms the feasibility of using 3D printing technique in the research field of intracranial artery diseases. Further investigations are warranted to optimize this technique and translate it into clinical practice.

Application of 3-dimensional printing in hand surgery for production of a novel bone reduction clamp

Three-dimensional printing is being rapidly incorporated in the medical field to produce external prosthetics for improved cosmesis and fabricated molds to aid in presurgical planning. Biomedically engineered products from 3-dimensional printers are also utilized as implantable devices for knee arthroplasty, airway orthoses, and other surgical procedures. Although at first expensive and conceptually difficult to construct, 3-dimensional printing is now becoming more affordable and widely accessible. In hand surgery, like many other specialties, new or customized instruments would be desirable; however, the overall production cost restricts their development. We are presenting our step-by-step experience in creating a bone reduction clamp for finger fractures using 3-dimensional printing technology. Using free, downloadable software, a 3-dimensional model of a bone reduction clamp for hand fractures was created based on the senior author's (M.V.M.) specific design, previous experience, and preferences for fracture fixation. Once deemed satisfactory, the computer files were sent to a 3-dimensional printing company for the production of the prototypes. Multiple plastic prototypes were made and adjusted, affording a fast, low-cost working model of the proposed clamp. Once a workable design was obtained, a printing company produced the surgical clamp prototype directly from the 3-dimensional model represented in the computer files. This prototype was used in the operating room, meeting the expectations of the surgeon. Three-dimensional printing is affordable and offers the benefits of reducing production time and nurturing innovations in hand surgery. This article presents a step-by-step description of our design process using online software programs and 3-dimensional printing services. As medical technology advances, it is important that hand surgeons remain aware of available resources, are knowledgeable about how the process works, and are able to take advantage of opportunities in order to advance the field.

3D volumetric analysis for planning breast reconstructive surgery

Breast reconstruction plays an integral role in the holistic management of breast cancer, with assessment of breast volume, shape, and projection vital in planning breast reconstruction surgery. Current practice includes two-dimensional (2D) photography and visual estimation in selecting ideal volume and shape of breast implants or soft-tissue flaps. Other objective quantitative means of calculating breast volume have been reported, such as direct anthropomorphic measurements or three-dimensional (3D) photography, but none have proven reliably accurate. We describe a novel approach to volumetric analysis of the breast, through the creation of a haptic, tactile model, or 3D print of scan data. This approach comprises use of a single computed tomography (CT) or magnetic resonance imaging (MRI) scan for volumetric analysis, which we use to compare to simpler estimation techniques, create software-generated 3D reconstructions, calculate, and visualize volume differences, and produce biomodels of the breasts using a 3D printer for tactile appreciation of volume differential. Using the technique described, parenchymal volume was assessed and calculated using CT data. A case report was utilized in a pictorial account of the technique, in which a volume difference of 116 cm(3) was calculated, aiding reconstructive planning. Preoperative planning, including volumetric analysis can be used as a tool to aid esthetic outcomes and attempt to reduce operative times in post-mastectomy breast reconstruction surgery. The combination of accurate volume calculations and the production of 3D-printed haptic models for tactile feedback and operative guidance are evolving techniques in volumetric analysis and preoperative planning in breast reconstruction.