3D-printed haptic "reverse" models for preoperative planning in soft tissue reconstruction: a case report

Pushing the Limits in Extremity Reconstruction Using Virtual Surgical Planning: A Case Series Study

SUMMARY

Technology is advancing in benefit to solving complex problems. Preoperative planning is essential in any reconstructive process given the importance of achieving good results. New technologies facilitate the process to anticipate intraoperative findings. Virtual surgical planning has contributed in the evolution of craniomaxillofacial surgery. However, limited reports have been published regarding its usefulness in extremity reconstruction. The aim of this study was to push the limits and evaluate the use of virtual surgical planning with three-dimensional images for reconstruction of complex extremity defects using a free, open-source software. Patient candidates for upper or lower extremity microsurgical reconstruction with multiple defects or defects requiring reconstruction of various tissue components were included. Computed tomography angiography images were analyzed for virtual surgical planning using Horos software (Horos, Annapolis, Md.). Two upper and eight lower extremities were reconstructed with free flaps using virtual surgical planning; six cases had multiple defects, and four cases underwent different tissue components reconstruction. The postoperative period was uneventful, and there was no flap failure. A didactic video of the process and examples of some cases are presented. Virtual surgical planning is a powerful planning method, and the authors propose its use in complex extremity defects reconstruction.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Design of a Single-Material Complex Structure Anthropomorphic Robotic Hand

In the field of robotic hand design, soft body and anthropomorphic design are two trends with a promising future. Designing soft body anthropomorphic robotic hands with human-like grasping ability, but with a simple and reliable structure, is a challenge that still has not been not fully solved. In this paper, we present an anatomically correct robotic hand 3D model that aims to realize the human hand's functionality using a single type of 3D-printable material. Our robotic hand 3D model is combined with bones, ligaments, tendons, pulley systems, and tissue. We also describe the fabrication method to rapidly produce our robotic hand in 3D printing, wherein all parts are made by elastic 50 A (shore durometer) resin. In the experimental section, we show that our robotic hand has a similar motion range to a human hand with substantial grasping strength and compare it with the latest other designs of anthropomorphic robotic hands. Our new design greatly reduces the fabrication cost and assembly time. Compared with other robotic hand designs, we think our robotic hand may induce a new approach to the design and production of robotic hands as well as other related mechanical structures.

Computed Tomography in Limb Salvage and Deformity Correction-3D Assessment, Indications, Radiation Exposure, and Safety Considerations

Computed tomography (CT) is an essential tool in orthopedic surgery but is known to be a method with that entails radiation exposure. CT increases the risk of developing fatal cancer, which should not be underestimated. However, patients with bone defects and/or deformities must frequently undergo numerous investigations during their treatment. CT is used for surgical planning, evaluating callus maturation, alignment measurement, length measurement, torsion measurement, and angiography. This study explores the indications in CT scans for limb lengthening and deformity correction and estimates the effective radiation dose. These results should help avoid unnecessary radiation exposure by narrowing the examination field and by providing explicit scanning indications. For this study, 19 posttraumatic patients were included after the bone reconstruction of 21 lower limbs. All patients underwent CT examinations during or after treatment with an external ring fixator. The mean effective dose was 3.27 mSv, with a mean cancer risk of 1:117,014. The effective dose depended on the location and indication of measurement, with a mean dose of 0.04 mSv at the ankle up to 6.8 mSv (or higher) for vascular depictions. CT evaluation, with or without 3D reconstruction, is a crucial tool in complex bone reconstruction and deformity treatments. Therefore, strict indications are necessary to reduce radiation exposure-especially in young patients-without compromising the management of their patients.

3D-printed, patient-specific DIEP flap templates for preoperative planning in breast reconstruction: a prospective case series

Background

Modern imaging technologies, such as computed tomographic angiography (CTA), can be useful for preoperative assessment in deep inferior epigastric artery perforator (DIEP) flap surgery. Planning perforator flap design can lead to improved surgical efficiency. However, current imaging modalities are limited by being displayed on a two-dimensional (2D) surface. In contrast, a 3D-printed model provides tactile feedback that facilitates superior understanding. Hence, we have 3D-printed patient-specific deep inferior epigastric artery perforator (DIEP) templates, in an affordable and convenient manner, for preoperative planning.

Methods

Twenty consecutive patients undergoing 25 immediate or delayed post-mastectomy autologous breast reconstruction with DIEP or muscle-sparing transverse rectus abdominis (MS-TRAM) flaps are recruited prospectively. Using free, open-source softwares (3D Slicer, Autodesk MeshMixer, and Cura) and desktop 3D printers (Ultimaker 3E and Moment), we created a template based on a patient's abdominal wall anatomy from CTA, with holes and lines indicating the position of perforators, their intramuscular course and the DIEA pedicle.

Results

The mean age of patients was 52 [38-67]. There were 15 immediate and 10 delayed reconstructions. 3D printing time took mean 18 hours and 123.7 g of plastic filament, which calculates to a mean material cost of AUD 8.25. DIEP templates accurately identified the perforators and reduced intraoperative perforator identification by 7.29 minutes (P=0.02). However, the intramuscular dissection time was not affected (P=0.34). Surgeons found the template useful for preoperative marking (8.6/10) and planning (7.9/10), but not for intramuscular dissection (5.9/10). There were no immediate flap-related complications.

Conclusions

Our 3D-printed, patient-specific DIEP template is accurate, significantly reduces intraoperative perforator identification time and, hence, may be a useful tool for preoperative planning in autologous breast reconstruction.

Simulation Surgery Using 3D 3-layer Models for Congenital Anomaly

We made realistic, three-dimensional, computer-assisted 3-layered elastic models of the face. The surface layer is made of polyurethane, the intermediate layer is silicone, and the deep layer is salt, representing the skin, subcutaneous tissue, and the bone. We have applied these 3-layer models to congenital anomaly cases and have understood that these models have a lot of advantages for simulation surgery.

Methods

We made 8 models. The models consisted of 2 models of 2 cases with Crouzon disease, 1 model of Binder syndrome, 1 model of facial cleft, 2 models of one case with Goldenhar syndrome, 1 model of cleft lip and palate, and 1 model of the hemifacial macrosomia.

Results

We could try several methods, could recognize whether the graft size is adequate, and could visualize the change of the facial contour. We could analyze how to approach the osteotomy line and actually perform osteotomy. The changes of the lower facial contour can be observed. We grafted the models of the graft and confirmed that the incisions could be closed well. We were able to visualize the change in the soft tissue contour by simulating distraction.

Conclusions

The most versatile merit of our models is that we could visualize the change of the soft tissue by movement of the hard tissue with bone graft, distraction osteogenesis, and so on. We must improve the model further to make it more realistic.

Error Measurement Between Anatomical Porcine Spine, CT Images, and 3D Printing

RATIONALE AND OBJECTIVES

3D printers are increasingly used in medical applications such as surgical planning, creation of implants and prostheses, and medical education. For the creation of reliable 3D printed models of the vertebral column, processing must be performed on CT images. This processing must be assessed and validated so that any error of the printed model can be recognized and minimized.

MATERIAL AND METHODS

In order to perform this validation, 10 CT scans of porcine lumbar spinal vertebra were used, which were then dissected and scanned again. CT image processing was performed to obtain a mesh and perform 3D printing.

RESULTS

There was no statistical difference among the four different levels of vertebrae measurements (first CT images, second CT images, anatomical piece of porcine bone and 3D printing of porcine bone; One Way repeated measure ANOVA, F < F_crit, p value > α = 0.05). The Intraclass Correlation also revealed a mean intraclass correlation coefficient (3,1) = 0.9553, which describes the reliability of all four levels in addition to the reliability of the data between porcine samples subjected to different levels of measurement. This shows that the average error is less than 1 mm.

CONCLUSIONS

The measurements of models created with 3D printers using the pipeline described in this paper have an average error of 0.60 mm with CT images and 0.73 mm with anatomical piece. Thus, 3D printed models accurately reflect in vivo bones and provide accurate 3D impressions to assist in surgical planning.

Development of a 3-D Printing Laboratory for Foot and Ankle Applications

This article is a guide to starting a 3-dimensional (3-D) print laboratory; 3-D models of complicated foot and ankle pathology can enhance surgical planning, improve patient and medical trainee education, and aid in research. This article discusses the variables that must be considered when creating a 3-D printing laboratory, including the hardware, software, printing materials, and procedures. Herein is a basic outline of what is required to develop a foot and ankle 3-D printing laboratory.

From digital world to real life: a robotic approach to the esophagogastric junction with a 3D printed model

Background

Three-dimensional (3D) printing may represent a useful tool to provide, in surgery, a good representation of surgical scenario before surgery, particularly in complex cases. Recently, such a technology has been utilized to plan operative interventions in spinal, neuronal, and cardiac surgeries, but few data are available in the literature about their role in the upper gastrointestinal surgery. The feasibility of this technology has been described in a single case of gastroesophageal reflux disease with complex anatomy due to a markedly tortuous descending aorta.

Methods

A 65-year-old Caucasian woman was referred to our Department complaining heartburn and pyrosis. A chest computed tomography evidenced a tortuous thoracic aorta and consequent compression of the esophagus between the vessel and left atrium. A “dysphagia aortica” has been diagnosed. Thus, surgical treatment of anti-reflux surgery with separation of the distal esophagus from the aorta was planned. To define the strict relationship between the esophagus and the mediastinal organs, a life-size 3D printed model of the esophagus including the proximal stomach, the thoracic aorta and diaphragmatic crus, based on the patient’s CT scan, was manufactured.

Results

The robotic procedure was performed with the da Vinci Surgical System and lasted 175 min. The surgeons had navigational guidance during the procedure since they could consult the 3D electronically superimposed processed images, in a “picture-in-picture” mode, over the surgical field displayed on the monitor as well as on the robotic headset. There was no injury to the surrounding organs and, most importantly, the patient had an uncomplicated postoperative course.

Conclusions

The present clinical report highlights the feasibility, utility and clinical effects of 3D printing technology for preoperative planning and intraoperative guidance in surgery, including the esophagogastric field. However, the lack of published data requires more evidence to assess the effectiveness and safety of this novel surgical-applied printing technology.

Assessment of a Novel Computer Algorithm for Printing a 3-Dimensional Nasal Prosthetic

Importance

The introduction and evaluation of a novel technique to create nasal prostheses with 3-dimensional (3-D) imaging software may circumvent the need for an anaplastologist.

Objectives

To describe a novel computer algorithm for the creation of a 3-D model of a nose and to evaluate the similarity of appearance of the nasal prosthesis with that of the individual's nose.

Design, Setting, and Participants

A prospective pilot study with a cross-sectional survey was conducted from August 1 to October 31, 2016, at a tertiary care academic center. Five volunteers were used for creation of the nasal prostheses, and 36 survey respondents with a medical background were involved in evaluating the nasal prostheses.

Exposures

A computer algorithm using a 3-D animation software (Blender; Blender Foundation) and Adobe Photoshop CS6 (Adobe Systems) were used to create a 3-D model of a nose. Photographs of 5 volunteers were processed with the computer algorithm. The model was then printed using a desktop 3-D printer. Attending physicians, residents, and medical students completed a survey and were asked to rate the similarity between the individuals' photographs and their 3-D printed nose on a Likert-type scale.

Main Outcomes and Measures

The similarity between 3-D printed nasal models and photographs of the volunteers' noses based on survey data.

Results

Thirty-six survey respondents evaluated 4 views for each of the 5 modeled noses (from 4 women and 1 man; mean [SD] age, 26.6 [5.7] years). The mean (SD) score for the overall similarity between the photographs and the 3-D models was 8.42 (1.34). The mean scores for each nasal comparison ranged from 7.97 to 8.62. According to the survey, respondents were able to match the correct 3-D nose to the corresponding volunteers' photographs in 171 of 175 photographs (97.7%). All surveyed clinicians indicated that they would consider using this tool to create a temporary prosthesis instead of referring to a prosthodontist.

Conclusions and Relevance

This algorithm can be used to model and print a 3-D prosthesis of a human nose. The printed models closely depicted the photographs of each volunteer's nose and can potentially be used to create a temporary prosthesis to fill external nasal defects. The appropriate clinical application of this technique is yet to be determined.

Anatomy Visualizations Using Stereopsis: Current Methodologies in Developing Stereoscopic Virtual Models in Anatomical Education

Technology for developing three-dimensional (3D) virtual models in anatomical sciences education has seen a great improvement in recent years. Various data used for creating stereoscopic virtual models have also been constantly improving. This paper focuses specifically on the methodologies of creating stereoscopic virtual models and the techniques and materials used in developing stereoscopic virtual models from both our previous studies and other published literature. The presentation and visualization of stereoscopic models are highlighted, and the benefits and limitations of stereoscopic models are discussed. The practice of making 3D measurements on the lengths, angles, and volumes of models can potentially be used to help predict typical measurement parameters of anatomical structures and for the placement of surgical instruments. Once stereoscopic virtual models have been constructed, their visualization and presentation can be implemented in anatomy education and clinical surgical trainings.

In-House Manufacture of Sterilizable, Scaled, Patient-Specific 3D-Printed Models for Rhinoplasty

BACKGROUND

Rhinoplasty relies on clear patient communication and precise execution of a three-dimensional (3D) plan to achieve optimal results. As 3D imaging and printing continue to grow in popularity within the medical field, rhinoplasty surgeons have begun to leverage these resources as an aid to preoperative planning, patient communication, and the technical performance of this challenging operation.

OBJECTIVES

Utilizing departmentally available resources and open-access 3D imaging platforms, we have developed an affordable, reproducible protocol for rapid in-house virtual surgical planning (VSP) and subsequent manufacture of 3D-printed rhinoplasty models.

METHODS

Preoperative 3D photographic images underwent virtual rhinoplasty using a freely available 3D imaging and sculpting program (BlenderTM [Version 2.78, Amsterdam, The Netherlands]). Once the ideal postoperative result was digitally achieved, scaled, sterilizable, and patient-specific 3D models of the preoperative and ideal postoperative result were manufactured in-house using a departmentally owned 3D printer.

RESULTS

3D-printed models have successfully been manufactured and employed for 12 patients undergoing rhinoplasty. The average time to prepare a set of pre- and postoperative models was 3 hours, while the printing process required 18 to 24 hours per model. Each set of surgical models can be manufactured at a total materials cost of approximately $5.00.

CONCLUSIONS

We describe an affordable means to construct sterilizable, scaled, patient-specific 3D-printed models for rhinoplasty. This technique may become of increasing interest to academic and cosmetic centers as hardware costs of 3D printers continue to fall.

LEVEL OF EVIDENCE: 4

Use of Three-dimensional Printing in Orthopaedic Surgical Planning

Background

Three-dimensional (3D) printing is a technique based on overlapping layers of a material (eg, plastic, clay, and metal). The widespread implementation of 3D printers has resulted in a notable increase in use. Fields such as construction, engineering, and medicine benefit from this technique.

Aim

The use of 3D printed scale models permits better surgical planning and results.

Methods

The models were created based on CT images of seven patients (age range, 5 to 61 years) with different pathologies who were candidates for surgery.

Results

Surgical time decreased as a result of detailed surgical planning with printed models. This technique also was associated with a decrease in bleeding, a reduction in the amount of anesthesia required, and greater precision. In some patients, a change in surgical strategy was noted, thus allowing for a reduction in the number of surgeries and the aggressiveness of surgery. Finally, the preoperative practice (virtual and physical osteotomies using cutting tools) that was performed in two cases allowed the surgeon to evaluate the different approach alternatives and establish the best strategy.

Conclusions

The use of 3D-printed anatomic models has improved surgical planning, especially for patients in whom the conventional techniques are insufficient for establishing a proper strategy. The extra information provided by 3D-printed models can lead to a better intervention strategy, which is beneficial for patients because it decreases the risks, procedure times, and recovery times.

Enabling personalized implant and controllable biosystem development through 3D printing

The impact of additive manufacturing in our lives has been increasing constantly. One of the frontiers in this change is the medical devices. 3D printing technologies not only enable the personalization of implantable devices with respect to patient-specific anatomy, pathology and biomechanical properties but they also provide new opportunities in related areas such as surgical education, minimally invasive diagnosis, medical research and disease models. In this review, we cover the recent clinical applications of 3D printing with a particular focus on implantable devices. The current technical bottlenecks in 3D printing in view of the needs in clinical applications are explained and recent advances to overcome these challenges are presented. 3D printing with cells (bioprinting); an exciting subfield of 3D printing, is covered in the context of tissue engineering and regenerative medicine and current developments in bioinks are discussed. Also emerging applications of bioprinting beyond health, such as biorobotics and soft robotics, are introduced. As the technical challenges related to printing rate, precision and cost are steadily being solved, it can be envisioned that 3D printers will become common on-site instruments in medical practice with the possibility of custom-made, on-demand implants and, eventually, tissue engineered organs with active parts developed with biorobotics techniques.

The precision and reliability evaluation of 3-dimensional printed damaged bone and prosthesis models by stereo lithography appearance

Recently, clinical application of 3D printed model was increasing. However, there was no systemic study for confirming the precision and reliability of 3D printed model. Some senior clinical doctors mistrusted its reliability in clinical application. The purpose of this study was to evaluate the precision and reliability of stereolithography appearance (SLA) 3D printed model.Some related parameters were selected to research the reliability of SLA 3D printed model. The computed tomography (CT) data of bone/prosthesis and model were collected and 3D reconstructed. Some anatomical parameters were measured and statistical analysis was performed; the intraclass correlation coefficient (ICC) was used to was used to evaluate the similarity between the model and real bone/prosthesis. the absolute difference (mm) and relative difference (%) were conducted. For prosthesis model, the 3-dimensional error was measured.There was no significant difference in the anatomical parameters except max height (MH) of long bone. All the ICCs were greater than 0.990. The maximum absolute and relative difference were 0.45 mm and 1.10%; The 3-dimensional error analysis showed that positive/minus distance were 0.273 mm/0.237 mm.The application of SLA 3D printed model in diagnosis and treatment process of complex orthopedic disease was reliable and precise.

Evaluating the Use of Cleft Lip and Palate 3D-Printed Models as a Teaching Aid

OBJECTIVE

Visualization tools are essential for effective medical education, to aid students understanding of complex anatomical systems. Three dimensional (3D) printed models are showing a wide-reaching potential in the field of medical education, to aid the interpretation of 2D imaging. This study investigates the use of 3D-printed models in educational seminars on cleft lip and palate, by comparing integrated "hands-on" student seminars, with 2D presentation seminar methods.

SETTING

Cleft lip and palate models were manufactured using 3D-printing technology at the medical school.

PARTICIPANTS

Sixty-seven students from two medical schools participated in the study.

DESIGN

The students were randomly allocated to 2 groups. Knowledge was compared between the groups using a multiple-choice question test before and after the teaching intervention. Group 1 was the control group with a PowerPoint presentation-based educational seminar and group 2 was the test group, with the same PowerPoint presentation, but with the addition of a physical demonstration using 3D-printed models of unilateral and bilateral cleft lips and palate.

RESULTS

The level of knowledge gained was established using a preseminar and postseminar assessment, in 2 different institutions, where the addition of the 3D-printed model resulted in a significant improvement in the mean percentage of knowledge gained (44.65% test group; 32.16%; control group; p = 0.038). Student experience was assessed using a postseminar survey, where students felt the 3D-printed model significantly improved the learning experience (p = 0.005) and their visualization (p = 0.001).

CONCLUSIONS

This study highlights the benefits of the use of 3D-printed models as visualization tools in medical education and the potential of 3D-printing technology to become a standard and effective tool in the interpretation of 2D imaging.

Clinical Applications of 3D Printing: Primer for Radiologists

Three-dimensional (3D) printing refers to a number of manufacturing technologies that create physical models from digital information. Radiology is poised to advance the application of 3D printing in health care because our specialty has an established history of acquiring and managing the digital information needed to create such models. The 3D Printing Task Force of the Radiology Research Alliance presents a review of the clinical applications of this burgeoning technology, with a focus on the opportunities for radiology. Topics include uses for treatment planning, medical education, and procedural simulation, as well as patient education. Challenges for creating custom implantable devices including financial and regulatory processes for clinical application are reviewed. Precedent procedures that may translate to this new technology are discussed. The task force identifies research opportunities needed to document the value of 3D printing as it relates to patient care.

3D Volumetric Modeling and Microvascular Reconstruction of Irradiated Lumbosacral Defects after Oncologic Resection

Background

Locoregional flaps are sufficient in most sacral reconstructions. However, large sacral defects due to malignancy necessitate a different reconstructive approach, with local flaps compromised by radiation and regional flaps inadequate for broad surface areas or substantial volume obliteration. In this report, we present our experience using free muscle transfer for volumetric reconstruction, in such cases, and demonstrate three-dimensional (3D) haptic models of the sacral defect to aid preoperative planning.

Methods

Five consecutive patients with irradiated sacral defects secondary to oncologic resections were included, surface area ranging from 143–600 cm². Latissimus dorsi (LD)-based free flap sacral reconstruction was performed in each case, between 2005 and 2011. Where the superior gluteal artery was compromised, the subcostal artery (SA) was used as a recipient vessel. Microvascular technique, complications, and outcomes are reported. The use of volumetric analysis and 3D printing is also demonstrated, with imaging data converted to 3D images suitable for 3D printing with Osirix software (Pixmeo, Geneva, Switzerland). An office-based, desktop 3D printer was used to print 3D models of sacral defects, used to demonstrate surface area and contour and produce a volumetric print of the dead space needed for flap obliteration.

Results

The clinical series of LD free flap reconstructions is presented, with successful transfer in all cases, and adequate soft-tissue cover and volume obliteration achieved. The original use of the SA as a recipient vessel was successfully achieved. All wounds healed uneventfully. 3D printing is also demonstrated as a useful tool for 3D evaluation of volume and dead space.

Conclusion

Free flaps offer unique benefits in sacral reconstruction where local tissue is compromised by irradiation and tumor recurrence, and dead space requires accurate volumetric reconstruction. We describe for the first time the use of the SA as a recipient in free flap sacral reconstruction. 3D printing of haptic bio-models is a rapidly evolving field with a substantial role in preoperative planning.

Surgical applications of three-dimensional printing: a review of the current literature & how to get started

Three dimensional (3D) printing involves a number of additive manufacturing techniques that are used to build structures from the ground up. This technology has been adapted to a wide range of surgical applications at an impressive rate. It has been used to print patient-specific anatomic models, implants, prosthetics, external fixators, splints, surgical instrumentation, and surgical cutting guides. The profound utility of this technology in surgery explains the exponential growth. It is important to learn how 3D printing has been used in surgery and how to potentially apply this technology. PubMed was searched for studies that addressed the clinical application of 3D printing in all surgical fields, yielding 442 results. Data was manually extracted from the 168 included studies. We found an exponential increase in studies addressing surgical applications for 3D printing since 2011, with the largest growth in craniofacial, oromaxillofacial, and cardiothoracic specialties. The pertinent considerations for getting started with 3D printing were identified and are discussed, including, software, printing techniques, printing materials, sterilization of printing materials, and cost and time requirements. Also, the diverse and increasing applications of 3D printing were recorded and are discussed. There is large array of potential applications for 3D printing. Decreasing cost and increasing ease of use are making this technology more available. Incorporating 3D printing into a surgical practice can be a rewarding process that yields impressive results.

3D haptic modelling for preoperative planning of hepatic resection: A systematic review

Introduction and background

Three dimensional (3D) printing has gained popularity in the medical field because of increased research in the field of haptic 3D modeling. We review the role of 3D printing with specific reference to liver directed applications.

Methods

A literature search was performed using the scientific databases Medline and PubMed. We performed this in-line with the PRISMA [20] statement. We only included articles in English, available in full text, published about adults, about liver surgery and published between 2005 and 2015. The 3D model of a patient's liver venous vasculature and metastasis was prepared from a CT scan using Osirix software (Pixmeo, Gineva, Switzerland) and printed using our 3D printer (MakerBot Replicator Z18, US). To validate the model, measurements from the inferior vena cava (IVC) were compared between the CT scan and the 3D printed model.

Results

A total of six studies were retrieved on 3D printing directly related to a liver application. While stereolithography (STL) remains the gold standard in medical additive manufacturing, Fused Filament Fabrication (FFF), is cheaper and may be more applicable. We found our liver 3D model made by FFF had a 0.1 ± 0.06 mm margin of error (mean ± standard deviation) compared with the CT scans.

Conclusion

3D printing in general surgery is yet to be thoroughly exploited. The most relevant feature of interest with regard to liver surgery is the ability to view the 3D dimensional relationship of the various hepatic and portal veins with respect to tumor deposits when planning hepatic resection.

Systematic review registration number: researchregistry1348.

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3D printing allows a fast, accurate and inexpensive production of a 3D liver model.

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A 3D printed model is excellent for education of junior staff as it offers insight to a patient's unique anatomy.

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3D printed models could also aid in patient education and facilitate surgery by obtaining informed consent.

From 3-Dimensional Printing to 5-Dimensional Printing: Enhancing Thoracic Surgical Planning and Resection of Complex Tumors

PURPOSE

Three-dimensional (3D) printing of anatomic models for complex surgical cases improves patient and resident education, operative team planning, and guides the operation. Our group describes two additional dimensions.

DESCRIPTION

The process of 5-dimensional (5D) printing was developed for surgical planning. Pretreatment computed tomography and positron emission tomography scans were reformatted and fused. Selected anatomy from these studies, along with posttreatment computed tomography and magnetic resonance images, were coregistered and segmented. This fused anatomy was converted into stereolithography files for 3D printing.

EVALUATION

A patient presenting with a complex thoracic tumor was selected for 5D printing. 3D and 5D models were prepared to allow surgical teams to directly evaluate and compare the added benefits of information provided by printing in 5 dimensions.

CONCLUSIONS

Printing 5D models in patients with complex thoracic pathology facilitates surgical planning, selecting margins for resection, anticipating potential difficulties, teaching for learners, and education for patients.

Three-dimensional printing as an aid to airway evaluation after tracheotomy in a patient with laryngeal carcinoma

Background

Difficult airway may result in significant morbidity and mortality. Proficient airway evaluation, therefore, is one of the key elements in the safe conduct of anesthesia. A three-dimensional (3D) printing model was recently introduced for medical application. 3D printing is a fast, convenient, and relatively affordable technique. We present a case in which a 3D-printed airway model was successfully used for airway evaluation.

Case presentation

A 77-year-old man who had previously undergone total laryngectomy was scheduled for resection of a pelvic mass. The condition of his airway, however, complicated the procedure. Routine methods to evaluate his airway were not suitable. Therefore, the patient’s computed tomography imaging data were used to generate stereolithography files and then to print out 3D models of his trachea. These 3D models enhanced our understanding of his tracheal morphology. They helped us devise a preanesthesia plan and effectively execute it without complications.

Conclusion

3D printing models allow better understanding of morphological changes in the airway and aid preanesthesia planning. The successful outcome of our case suggests 3D printing is a potent tool for evaluating difficult and more widespread use is encouraged.

Individualizing Management of Complex Esophageal Pathology Using Three-Dimensional Printed Models

PURPOSE

In complex esophageal cases, conventional two-dimensional imaging is limited in demonstrating anatomic relationships. We describe the utility of three-dimensional (3D) printed models for complex patients to individualize care.

DESCRIPTION

Oral effervescent agents, with positive enteric contrast, distended the esophagus during computed tomography (CT) scanning to facilitate segmentation during post-processing. The CT data were segmented, converted into a stereolithography file, and printed using photopolymer materials.

EVALUATION

In 1 patient with a left pneumonectomy, aortic bypass, and esophageal diversion, 3D printing enabled visualization of the native esophagus and facilitated endoscopic mucosal resection, followed by hiatal dissection and division of the gastroesophageal junction as treatment. In a second patient, 3D printing allowed enhanced visualization of multiple esophageal diverticula, allowing for optimization of the surgical approach.

CONCLUSIONS

Printing of 3D anatomic models in patients with complex esophageal pathology facilitates planning the optimal surgical approach and anticipating potential difficulties for the multidisciplinary team. These models are invaluable for patient education.

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.