Three-Dimensional Printing of Perforator Vascular Anatomy

Abstract

Sir: The use of three-dimensional printing has increased in recent years with the advent of commercially available three-dimensional printers and lower costs. Computed tomographic data can be obtained rapidly and incorporated into three-dimensional reconstructions visualized in two dimensions. This information can be used to produce a physical object using progressive layering of different polymers or materials with a three-dimensional printer. Production of three-dimensional models allows improved visualization and manipulation of anatomical structures compared with two-dimensional representations. They can be used for surgical planning, implant design, and education.1 Three-dimensional models have also been used for training on patient-specific models to simulate surgical procedures to help understand difficult anatomy, predict complications, and potentially reduce operating time.1–41–41–41–4 We produced a three-dimensional model to facilitate understanding of the regional anatomy of the internal mammary artery. We chose the internal mammary artery perforator system, as its relationship to surrounding ribs is important in the dissection and identification of the dominant perforator while raising the internal mammary artery perforator flap. To create a three-dimensional model of the dominant internal mammary artery perforator, a fresh cadaver was injected with the modified lead oxide technique described previously.5 The cadaver was obtained through the Dalhousie University Donor Program. Plain films and computed tomographic images of the cadaver were obtained and the data were analyzed using Materialise’s Interactive Medical Image Control System program (Materialise, Leuven, Belgium). Using the program, three-dimensional images of the dominant internal mammary artery perforator and surrounding structures were created (Fig. 1).Fig. 1: Three-dimensional reconstructions of the left bony thorax, internal mammary artery, and dominant left internal mammary artery perforator and lateral thoracic artery from cadaveric computed tomographic data using Materialise’s Interactive Medical Imaging Control System. (Left) Anterior-posterior, (center) oblique, and (right) posterior-anterior views (*, second internal mammary artery perforator; •, second rib; , lateral thoracic artery).The reconstruction was printed in three dimensions using a composite powder printing process on a ProJet x60 series printer with a Z-bond 90 infiltrant (3D Systems, Rock Hill, S.C.). This produces a three-dimensional object by successively laying down the infiltrant to build the model slice by slice based on the reconstruction. We report the first use of three-dimensional printing to produce vascular perforator anatomy. The dominant internal mammary artery perforator can be seen branching off of the internal mammary artery, through the second intercostal space and anastomosing with the lateral thoracic artery (Fig. 2).Fig. 2: Anteroposterior (left) and oblique (right) views of a three-dimensional model of the left bony thorax, internal mammary artery, and internal mammary artery perforator (*, second internal mammary artery perforator; •, second rib; , lateral thoracic artery). The lateral thoracic artery was based on cadaveric data and printed using a ProJet x60 series printer with a Z-bond 90 infiltrant (3D Systems, Rock Hill, S.C.).The use of three-dimensional printing to produce physical objects is the next step from three-dimensional reconstructions visualized on two-dimensional screens. It allows rapid manipulation and understanding of an individual’s anatomy by physically holding the object and being able to visualize it in multiple planes. This can be useful for teaching learners, and can be used as a tool to better explain the proposed surgery to patients using their own anatomy. One limitation of the process is the cost associated with production of the model, which can be anywhere from $400 to $1200. Also, due to the minuteness of perforator vessels, some smaller vessels do not endure the printing process due to the resolution limitations of the three-dimensional printer. This can be ameliorated with a larger model, albeit at a higher cost. Also, the materials used to make certain models are delicate, and rough handling can cause perforator branches to crack. However, postprinting processing with materials such as wax can create a durable model that can be used in clinics and teaching sessions. DISCLOSURE The authors have no financial interest in any of the products or devices mentioned in this article. Joshua A. Gillis, B.Sc., M.D. Steven F. Morris, M.D., M.Sc. Division of Plastic Surgery Dalhousie University Halifax, Nova Scotia, Canada