From CT scanning to 3-D printing technology for the preoperative planning in laparoscopic splenectomy

Precise planning based on 3D-printed dry-laboratory models can reduce perioperative complications of laparoscopic surgery for complex hepatobiliary diseases: a preoperative cohort study

BACKGROUND & AIMS

Complications after laparoscopic liver resection (LLR) are important factors affecting the prognosis of patients, especially for complex hepatobiliary diseases. The present study aimed to evaluate the value of a three-dimensional (3D) printed dry-laboratory model in the precise planning of LLR for complex hepatobiliary diseases.

METHODS

Patients with complex hepatobiliary diseases who underwent LLR were preoperatively enrolled, and divided into two groups according to whether using a 3D-printed dry-laboratory model (3D vs. control group). Clinical variables were assessed and complications were graded by the Clavien-Dindo classification. The Comprehensive Complication Index (CCI) scores were calculated and compared for each patient. Multivariable analysis was performed to determine the risk factors of postoperative complications.

RESULTS

Sixty-two patients with complex hepatobiliary diseases underwent the precise planning of LLR. Among them, thirty-one patients acquired the guidance of a 3D-printed dry-laboratory model, and others were only guided by traditional enhanced CT or MRI. The results showed no significant differences between the two groups in baseline characters. However, compared to the control group, the 3D group had a lower incidence of intraoperative blood loss, as well as postoperative 30-day and major complications, especially bile leakage (all P < 0.05). The median score on the CCI was 20.9 (range 8.7-51.8) in the control group and 8.7 (range 8.7-43.4) in the 3D group (mean difference, -12.2, P = 0.004). Multivariable analysis showed the 3D model was an independent protective factor in decreasing postoperative complications. Subgroup analysis also showed that a 3D model could decrease postoperative complications, especially for bile leakage in patients with intrahepatic cholelithiasis.

CONCLUSION

The 3D-printed models can help reduce postoperative complications. The 3D-printed models should be recommended for patients with complex hepatobiliary diseases undergoing precise planning LLR.

Feasibility and impact of three-dimensional (3D) printing technology in simulated teaching of congenital malformations

AIMS

This study aimed to investigate the feasibility and effectiveness of utilizing three-dimensional (3D) printing technology in the simulation teaching of congenital malformations.

METHODS

We conducted a comparative analysis between an experimental group that received traditional teaching supplemented with 3D printing model demonstrations and hands-on model operation, and a control group that received traditional teaching methods. Various parameters, including classroom interest, classroom interaction, learning enthusiasm, disease awareness, teaching satisfaction, and independent operation confidence, were assessed, along with theoretical and practical tests.

RESULTS

The results showed no significant difference in theoretical test scores between the two groups (91.92 ± 15.04 vs. 89.44 ± 14.89), but the practical test revealed a significantly higher number of qualified trainees in the experimental group compared to the control group (23 vs. 8). In terms of classroom engagement, both groups exhibited similar levels of interest (8.08 ± 1.52 vs. 8.74 ± 0.984), classroom interaction (7.88 ± 1.97 vs. 8.7 ± 1.33), learning enthusiasm (8.81 ± 1.021 vs. 8.52 ± 1.189), and disease awareness (8.58 ± 0.99 vs. 8.58 ± 0.99). However, the experimental group demonstrated significantly higher teaching satisfaction (8.81 ± 1.06 vs. 9.19 ± 0.96) and greater operation confidence (7.67 ± 2.56 vs. 5.5 ± 2.79) than the control group.

CONCLUSION

3D printing technology can be effectively utilized to create surgical teaching models, enhancing the confidence of standardized training doctors and improving teaching outcomes.

Image-guided orbital surgery: a preclinical validation study using a high-resolution physical model

OBJECTIVE

Preclinical validation study to assess the feasibility and accuracy of electromagnetic image-guided systems (EM-IGS) in orbital surgery using high-fidelity physical orbital anatomy simulators.

METHODS

EM-IGS platform, clinical software, navigation instruments and reference system (StealthStation S8, Medtronic) were evaluated in a mock operating theatre at the Royal Victoria Eye and Ear Hospital, a tertiary academic hospital in Dublin, Ireland. Five high-resolution 3D-printed model skulls were created using CT scans of five anonymised patients with an orbital tumour that previously had a successful orbital biopsy or excision. The ability of ophthalmic surgeons to achieve satisfactory system registration in each model was assessed. Subsequently, navigational accuracy was recorded using defined anatomical landmarks as ground truth. Qualitative feedback on the system was also attained.

RESULTS

Three independent surgeons participated in the study, one junior trainee, one fellow and one consultant. Across models, more senior participants were able to achieve a smaller system-generated registration error in a fewer number of attempts. When assessing navigational accuracy, submillimetre accuracy was achieved for the majority of points (16 landmarks per model, per participant). Qualitative surgeon feedback suggested acceptability of the technology, although interference from mobile phones near the operative field was noted.

CONCLUSION

This study suggests the feasibility and accuracy of EM-IGS in a preclinical validation study for orbital surgery using patient specific 3D-printed skulls. This preclinical study provides the foundation for clinical studies to explore the safety and effectiveness of this technology.

Just the gastrointestinal stromal tumor: A case report of medical modeling of a rectal gastrointestinal stromal tumor

A 54-year-old African-American male presented to the colorectal surgery clinic with the chief complaint of a painful anal swelling that had been ongoing for several weeks. An adequate rectal examination was not possible due to severe pain. Therefore, he was taken to the operating room for an exam under anesthesia where a presacral mass was identified. A transgluteal core needle biopsy was performed which was consistent with gastrointestinal stromal tumor. Computed tomography imaging identified a 16 cm ×10 cm ×9 cmrectal gastrointestinal stromal tumor. Given the size and location, the patient began treatment with neoadjuvant Imatinib. His progress was followed with serial computed tomography scans and clinic visits. A 3D model was created the tumor and surrounding structures to aide in pre- and intraoperative planning. The model was utilized during patient education and found to valuable in describing the potential for levator invasion and framing potential post-operative outcomes. The patient was able to undergo rectal preservation via a robotic low anterior resection with a transanal total mesorectal excision, coloanal anastomosis, and diverting ileostomy.

Preoperative Simulation of Ileal Pouch-Anal Anastomosis in Patients With Ulcerative Colitis Using a 3-Dimensional Printed Model

BACKGROUND

During restorative proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis-associated colorectal cancer or dysplasia, ileal pouch-anal handsewn anastomosis (IAA) is preferred to avoid the risk of cancer development in the remaining rectal mucosa. However, there is a risk of the ileal pouch not reaching the anus with this procedure. Here, we created deformable 3-dimensional (3D) models for simulation.

METHOD

Six patients who underwent IAA without vessel ligation and 5 patients who underwent ileal pouch-anal canal double-stapled anastomosis (IACA) because the ileal pouch did not reach the anus were studied. A 3D printer was used to create deformable 3D models from the data obtained from computed tomography scans. The positional relationship among the mesenteric arteries, pubis, and coccyx were evaluated.

RESULT

The distance between the superior mesenteric artery root and the tip of the ileal artery was longer in the IAA group than that in the IACA group (IAA vs IACA: 26.2 ± 2.1 cm vs 20.9 ± 1.6cm). The distance from the tip of the ileal artery to the coccyx (IAA vs IACA: 6.7 ± 1.7 cm vs 12.1 ± 2.1 cm) and the distance from the tip of the ileal artery to the lower edge of the pubis (IAA vs IACA; 8.1 ± 1.3 cm vs 12.7 ± 2.4 cm) were longer in the IACA group than those in the IAA group.

CONCLUSIONS

We established a method for creating 3D deformable models of patients with ileal pouch-anal anastomosis. These 3D models may be useful for preoperative simulation.

Progress in bioprinting technology for tissue regeneration

In recent years, due to the increase in diseases that require organ/tissue transplantation and the limited donor, on the other hand, patients have lost hope of recovery and organ transplantation. Regenerative medicine is one of the new sciences that promises a bright future for these patients by providing solutions to repair, improve function, and replace tissue. One of the technologies used in regenerative medicine is three-dimensional (3D) bioprinters. Bioprinting is a new strategy that is the basis for starting a global revolution in the field of medical sciences and has attracted much attention. 3D bioprinters use a combination of advanced biology and cell science, computer science, and materials science to create complex bio-hybrid structures for various applications. The capacity to use this technology can be demonstrated in regenerative medicine to make various connective tissues, such as skin, cartilage, and bone. One of the essential parts of a 3D bioprinter is the bio-ink. Bio-ink is a combination of biologically active molecules, cells, and biomaterials that make the printed product. In this review, we examine the main bioprinting strategies, such as inkjet printing, laser, and extrusion-based bioprinting, as well as some of their applications.

A scoping review on the trends of digital anatomy education

Digital technologies are changing the landscape of anatomy education. To reveal the trend of digital anatomy education across medical science disciplines, searches were performed using PubMed, EMBASE, and MEDLINE bibliographic databases for research articles published from January 2010 to June 2021 (inclusive). The search was restricted to publications written in English language and to articles describing teaching tools in undergraduate and postgraduate anatomy and pre-vocational clinical anatomy training courses. Among 156 included studies across six health disciplines, 35% used three-dimensional (3D) digital printing tools, 24.2% augmented reality (AR), 22.3% virtual reality (VR), 11.5% web-based programs, and 4.5% tablet-based apps. There was a clear discipline-dependent preference in the choice and employment of digital anatomy education. AR and VR were the more commonly adopted digital tools for medical and surgical anatomy education, while 3D printing is more broadly used for nursing, allied health and dental health education compared to other digital resources. Digital modalities were predominantly adopted for applied interactive anatomy education and primarily in advanced anatomy curricula such as regional anatomy and neuroanatomy. Moreover, there was a steep increase in VR anatomy combining digital simulation for surgical anatomy training. There is a consistent increase in the adoption of digital modalities in anatomy education across all included health disciplines. AR and VR anatomy incorporating digital simulation will play a more prominent role in medical education of the future. Combining multimodal digital resources that supports blended and interactive learning will further modernize anatomy education, moving medical education further away from its didactic history.

Accuracy and efficiency of an artificial intelligence-based pulmonary broncho-vascular three-dimensional reconstruction system supporting thoracic surgery: retrospective and prospective validation study

BACKGROUND

Anthropomorphic phantoms are used in surgical planning and intervention. Ideal accuracy and high efficiency are prerequisites for its clinical application. We aimed to develop a fully automated artificial intelligence-based three-dimensional (3D) reconstruction system (AI system) to assist thoracic surgery and to determine its accuracy, efficiency, and safety for clinical use.

METHODS

This AI system was developed based on a 3D convolutional neural network (CNN) and optimized by gradient descent after training with 500 cases, achieving a Dice coefficient of 89.2%. Accuracy was verified by comparing virtual structures predicted by the AI system with anatomical structures of patients in retrospective (n = 113) and prospective cohorts (n = 139) who underwent lobectomy or segmentectomy at the Peking University Cancer Hospital. Operation time and blood loss were compared between the retrospective cohort (without AI assistance) and prospective cohort (with AI assistance) for safety evaluation. The time consumption for reconstruction and the quality score were compared between the AI system and manual reconstruction software (Mimics®) for efficiency validation. This study was registered at https://www.chictr.org.cn as ChiCTR2100050985.

FINDINGS

The AI system reconstructed 13,608 pulmonary segmental branches from retrospective and prospective cohorts, and 1573 branches of interest corresponding to phantoms were detectable during the operation for verification, achieving 100% and 97% accuracy for segmental bronchi, 97.2% and 99.1% for segmental arteries, and 93.2% and 98.8% for segmental veins, respectively. With the assistance of the AI system, the operation time was shortened by 24.5 min for lobectomy (p < 0.001) and 20 min for segmentectomy (p = 0.007). Compared to Mimics®, the AI system reduced the model reconstruction time by 14.2 min (p < 0.001), and it also outperformed Mimics® in model quality scores (p < 0.001).

INTERPRETATION

The AI system can accurately predict thoracic anatomical structures with higher efficiency than manual reconstruction software. Constant optimization and larger population validation are required.

FUNDING

This study was funded by the Beijing Natural Science Foundation (No. L222020) and other sources.

Comparison of 2 open-sourced 3-dimensional modeling techniques for orthopaedic application

Objectives: Although 3-dimensional (3D) printing is becoming more widely adopted for clinical applications, it is yet to be accepted as part of standard practice. One of the key applications of this technology is orthopaedic surgical planning for urgent trauma cases. Anatomically accurate replicas of patients' fracture models can be produced to guide intervention. These high-quality models facilitate the design and printing of patient-specific implants and surgical devices. Therefore, a fast and accurate workflow will help orthopaedic surgeons to generate high-quality 3D printable models of complex fractures. Currently, there is a lack of access to an uncomplicated and inexpensive workflow. Methods: Using patient DICOM data sets (n = 13), we devised a novel, simple, open-source, and rapid modeling process using Drishti software and compared its efficacy and data storage with the 3D Slicer image computing platform. We imported the computed tomography image directory acquired from patients into the software to isolate the model of bone surface from surrounding soft tissue using the minimum functions. One pelvic fracture case was further integrated into the customized implant design practice to demonstrate the compatibility of the 3D models generated from Drishti. Results: The data sizes of the generated 3D models and the processing files that represent the original DICOM of Drishti are on average 27% and 12% smaller than that of 3D Slicer, respectively (both P < 0.05). The time frame needed to reach the stage of viewing the 3D bone model and the exporting of the data of Drishti is 39% and 38% faster than that of 3D Slicer, respectively (both P < 0.05). We also constructed a virtual model using third-party software to trial the implant design. Conclusions: Drishti is more suitable for urgent trauma cases that require fast and efficient 3D bone reconstruction with less hardware requirement. 3D Slicer performs better at quantitative preoperative planning and multilayer segmentation. Both software platforms are compatible with third-party programs used to produce customized implants that could be useful for surgical training. Level of Evidence: Level V.

Tribo-corrosive behavior of additive manufactured parts for orthopaedic applications

Background

Additive manufacturing (AM) being an integral component of the production offers a wide variety of applications in the production of different components. The medical industry after the introduction of Additive Manufacturing has resulted in several advancements. The production of intricate patient-specific implants is one of such advancements which greatly assist a surgeon during a surgery. Orthopedic implants apart from possessing good mechanical strength are also expected to exhibit good tribological and corrosion behavior. As a result, the development of various orthopaedic implants and tools has become simple with the use of additive manufacturing.

Objectives and Rationale

In the current paper an effort has been made to discuss actual scientific knowledge on the tribo-corrosive behavior of additive manufactured parts for orthopedic applications. Different studies dealing with the mechanisms of lubrication and friction in synovial joints have also been considered. A special focus has also been laid down to study the corrosive effect of implants on the human body. A section dedicated to texturing of orthopedic implants has also been provided. The paper further elaborates the different research challenges and issues related to the use of additive manufacturing for the production of optimized orthopedic implants.

Conclusion

The study revealed that additive manufacturing has greatly aided in the manufacture of different orthopaedic implants with enhanced properties. However, a detailed study of the effect of processes like friction, wear, lubrication and corrosion in these implants needs to be done. The performance of these implants in the presence of various synovial fluids also needs to be addressed. However, the lack of more biocompatible materials, scalability and cost issues hinder the widespread use of AM in the different orthopaedic applications.

The Role of 3D Printing in Planning Complex Medical Procedures and Training of Medical Professionals-Cross-Sectional Multispecialty Review

Medicine is a rapidly-evolving discipline, with progress picking up pace with each passing decade. This constant evolution results in the introduction of new tools and methods, which in turn occasionally leads to paradigm shifts across the affected medical fields. The following review attempts to showcase how 3D printing has begun to reshape and improve processes across various medical specialties and where it has the potential to make a significant impact. The current state-of-the-art, as well as real-life clinical applications of 3D printing, are reflected in the perspectives of specialists practicing in the selected disciplines, with a focus on pre-procedural planning, simulation (rehearsal) of non-routine procedures, and on medical education and training. A review of the latest multidisciplinary literature on the subject offers a general summary of the advances enabled by 3D printing. Numerous advantages and applications were found, such as gaining better insight into patient-specific anatomy, better pre-operative planning, mock simulated surgeries, simulation-based training and education, development of surgical guides and other tools, patient-specific implants, bioprinted organs or structures, and counseling of patients. It was evident that pre-procedural planning and rehearsing of unusual or difficult procedures and training of medical professionals in these procedures are extremely useful and transformative.

Three-D-printed simulator for kidney transplantation

BACKGROUND

Three-Dimensional (3D) printing technology can be used to manufacture training platforms for surgeons. Kidney transplantation offers a suitable model, since it mostly entails vascular and ureteric anastomoses.

METHODS

A new simulation platform for surgical training in kidney transplantation was realized and validated in this study. A combination of different 3-D printing technology was used to reproduce the key anatomy of lower abdomen, of pelvis, and of a kidney graft, including their mechanical properties.

RESULTS

Thirty transplantations were performed by two junior trainees with no previous experience in the area. Analysis of the times required to perform the simulated transplantation showed that proficiency was reached after about ten cases, as indicated by a flattening of the respective curves that corresponded to a shortening of about 40% and 47%, respectively, of the total time initially needed to perform the whole simulated transplantation. Although an objective assessment of the technical quality of the anastomoses failed to show a significant improvement throughout the study, a growth in self-confidence with the procedure was reported by both trainees.

CONCLUSION

The quality of the presented simulation platform aimed at reproducing in the highest possible way a realistic model of the operative setting and proved effective in providing an integrated training environment where technical skills are enhanced together with a team-training experience. As a result the trainees' self-confidence with the procedure resulted enforced. Three-D--printed models can also offer pre-operative patient-specific training when anatomical variants are anticipated by medical imaging. An analysis of the costs related to the use of this platform is also provided and discussed.

3D-Printing of Drug-Eluting Implants: An Overview of the Current Developments Described in the Literature

The usage of 3D-printing for drug-eluting implants combines the advantages of a targeted local drug therapy over longer periods of time at the precise location of the disease with a manufacturing technique that easily allows modifications of the implant shape to comply with the individual needs of each patient. Research until now has been focused on several aspects of this topic such as 3D-printing with different materials or printing techniques to achieve implants with different shapes, mechanical properties or release profiles. This review is intended to provide an overview of the developments currently described in the literature. The topic is very multifaceted and several of the investigated aspects are not related to just one type of application. Consequently, this overview deals with the topic of 3D-printed drug-eluting implants in the application fields of stents and catheters, gynecological devices, devices for bone treatment and surgical screws, antitumoral devices and surgical meshes, as well as other devices with either simple or complex geometry. Overall, the current findings highlight the great potential of the manufacturing of drug-eluting implants via 3D-printing technology for advanced individualized medicine despite remaining challenges such as the regulatory approval of individualized implants.

Radiological Society of North America (RSNA) 3D Printing Special Interest Group (SIG) clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: abdominal, hepatobiliary, and gastrointestinal conditions

Background

Medical 3D printing has demonstrated value in anatomic models for abdominal, hepatobiliary, and gastrointestinal conditions. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (SIG) provides appropriateness criteria for abdominal, hepatobiliary, and gastrointestinal 3D printing indications.

Methods

A literature search was conducted to identify all relevant articles using 3D printing technology associated with a number of abdominal pathologic processes. Each included study was graded according to published guidelines.

Results

Evidence-based appropriateness guidelines are provided for the following areas: intra-hepatic masses, hilar cholangiocarcinoma, biliary stenosis, biliary stones, gallbladder pathology, pancreatic cancer, pancreatitis, splenic disease, gastric pathology, small bowel pathology, colorectal cancer, perianal fistula, visceral trauma, hernia, abdominal sarcoma, abdominal wall masses, and intra-abdominal fluid collections.

Conclusion

This document provides initial appropriate use criteria for medical 3D printing in abdominal, hepatobiliary, and gastrointestinal conditions.

Utility of a three-dimensional printed pelvic model for lateral pelvic lymph node dissection

PURPOSE

In patients with advanced lower rectal cancer, the complex pelvic anatomy renders lateral pelvic lymph node dissection to be challenging. Therefore, we evaluated the utility of printing a three-dimensional (3D) pelvic model for lateral pelvic lymph node dissection.

METHODS

We included 22 patients who underwent lateral pelvic lymph node dissection for rectal cancer between June 2017 and February 2019. Using CT scans, 3D pelvic images and models were constructed and printed, respectively. Thirty colorectal surgeons subjectively evaluated the utility of 3D pelvic models based on a 5-point Likert scale questionnaire (1 = strongly disagree, 5 = strongly agree).

RESULTS

The average Likert score for the question "Would a 3D model be useful for understanding pelvic anatomy?" was 4.68. Cases with clinically diagnosed metastatic lymph nodes (4.79 ± 0.44) scored higher than those without them (4.38 ± 0.77, p = 0.02). For spatial comprehension of pelvic anatomy, 3D models scored higher (4.83) than 3D images (4.36, p < 0.001). The ease of use of 3D models and images was scored 4.60 and 4.20, respectively (p = 0.015). With experience, the 3D image reconstruction time decreased from 900 to 150 min.

CONCLUSION

The 3D pelvic models may be helpful for experienced surgeons to understand the pelvic anatomy in lateral pelvic lymph node dissection.

Robotic Treatment of Complex Splenic Artery Aneurysms with Deep Hilar Location: Technical Insights and Midterm Results

BACKGROUND

Splenic artery aneurysms are rare, but their occurrence is burdened by considerable mortality and morbidity rates. Although the indications to treatment are quite clear-cut, there is still debate on the first-choice technique of treatment (endovascular, open, or laparoscopic surgery). Recently, robotic surgery has been proposed as an alternative option in patients at high surgical risk. The present case series aims to assess the value of robotic treatment of splenic artery aneurysms in patients unfit for surgery.

METHODS

All cases of splenic artery aneurysms treated by robotic surgery at our center between 2014 and 2018 were retrospectively reviewed. Primary endpoints were clinical and technical success and disease-free survival.

RESULTS

Robotic surgery was used to treat four patients affected by splenic artery aneurysms, with the guidance of 3D printed patient-specific models. All patients, after aneurysm excision, received reconstruction of the splenic artery by direct anastomosis. All cases were treated successfully without mortality. Reintervention-free survival at 24-month mean follow-up is 100%, and no systemic complication of clinical relevance was reported. The mean time of organ ischemia was 45 min.

CONCLUSIONS

Robotic surgery is a safe and effective option in treating visceral aneurysms, providing the possibility to reconstruct the splenic artery after aneurysm excision.

Scaffold-free: A developing technique in field of tissue engineering

Scaffold-free tissue engineering can be considered as a rapidly developing technique in the field of tissue engineering. In the areas of regenerative medicine and wound healing, there is a demand of techniques where no scaffolds are used for the development of desired tissue. These techniques will overcome the problems of rejection and tissue failure which are common with scaffolds. Main breakthrough of scaffold free tissue engineering was after invention of 3-D printers which made it possible to print complex tissues which were not possible by conventional methods. Mathematical modeling is a prediction technique is used in tissue engineering for simulation of the model to be constructed. Coming to scaffold-free technique, mathematical modeling is necessary for the processing of the model that has to be bio-printed so as to avoid and changes in the final construct. Tissue construct is developed by use of non-destructive imaging techniques i.e. computed tomography (CT) and magnetic resonance imaging (MRI).In this review, we discussed about various mathematical models and the models which are widely used in bioprinting techniques such as Cellular Potts Model (CPM) and Cellular Particle Dynamic (CPD) model. Later, developed of 3-D tissue construct using micro CT scan images was explained. Finally, we discussed about scaffold free techniques such as 3-D bioprinting and cell sheet technology. In this manuscript, we proposed a cell sheet based bioprinting technique where mesenchymal stem cells (MSCs) on the surface of thermoresponsive polymer were subjected to mechanosensing either by introducing acoustic energies or stress created by polymeric strain energy function. Mechanosensing stimulus will trigger the intracellular signal transduction pathway leading to differentiation of the MSCs into desired cells.

An overview on 3D printing for abdominal surgery

BACKGROUND

Three-dimensional (3D) printing is a disruptive technology that is quickly spreading to many fields, including healthcare. In this context, it allows the creation of graspable, patient-specific, anatomical models generated from medical images. The ability to hold and show a physical object speeds up and facilitates the understanding of anatomical details, eases patient counseling and contributes to the education and training of students and residents. Several medical specialties are currently exploring the potential of this technology, including general surgery.

METHODS

In this review, we provide an overview on the available 3D printing technologies, together with a systematic analysis of the medical literature dedicated to its application for abdominal surgery. Our experience with the first clinical laboratory for 3D printing in Italy is also reported.

RESULTS

There was a tenfold increase in the number of publications per year over the last decade. About 70% of these papers focused on kidney and liver models, produced primarily for pre-interventional planning, as well as for educational and training purposes. The most used printing technologies are material jetting and material extrusion. Seventy-three percent of publications reported on fewer than ten clinical cases.

CONCLUSION

The increasing application of 3D printing in abdominal surgery reflects the dawn of a new technology, although it is still in its infancy. The potential benefit of this technology is clear, however, and it may soon lead to the development of new hospital facilities to improve surgical training, research, and patient care.

Trends in use of 3D printing in vascular surgery: a survey

INTRODUCTION

The purpose of the following research was to provide a systematic survey on the use of additive manufacturing in vascular surgery. The survey focuses on applications of 3D printing in endovascular surgery like endovascular aneurysm repair (EVAR), a quite unexplored application domain. 3D printing is an additive production process of three-dimensional objects starting from a three-dimensional digital model. This kind of manufacturing process is getting great attention in the medical field and new applications have emerged in recent years especially thanks to the combination of additive printing with 3D imaging techniques. The purpose of the study is to reflect on additive manufacturing and its potential as an inclusive manufacturing practice which can provide benefits at economic and societal level.

EVIDENCE ACQUISITION

The article first introduces the use of 3D printing in surgery by summarizing the results of previous reviews which reveal three main usages of 3D printing: anatomic models, surgical tools, implants and prostheses. These studies point out that vascular surgery is still an unexplored field of application of 3D printing. Starting from this result, a new survey was carried out in databases Pubmed, Elsevier, Research Gate and ACM Digital Library for terms related to 3D printing in vascular surgery using the following keywords: 3D printing, vascular surgery, EVAR, aneurysm. The search screened articles published up to 2019 for relevance and practical application of the technology in vascular surgery, in particular the topic is related to the treatment of complex abdominal aortic aneurysm.

EVIDENCE SYNTHESIS

Initially 437 records published up to 2019 were found, but then were narrowed down to 29 full-text articles. The findings reveal that in addition to the applications found in the previous studies, new experiments are ongoing related to the use of 3D printing in the "Off label" practice to manually fenestrate the stent to improve the accuracy of the EVAR.

CONCLUSIONS

Different applications of the use of 3D printing and digital imaging in vascular surgery have been experimented with a different maturity level. Whilst the technology has increased its potential in the latest years, the number of studies documented in the literature is still quite narrow. Further research is necessary to fully test the potential of 3D printing, also in combination with other technologies (e.g. 3D imaging and CNC cutting). Early experimentations show that these technologies have the potential to radically change the vascular surgery practice in the near future, in particular in treatment like EVAR, to improve the planning and therefore the success of the surgery.

Toward the improvement of 3D-printed vessels' anatomical models for robotic surgery training

Multi-Detector Computed Tomography is nowadays the gold standard for the pre-operative imaging for several surgical interventions, thanks to its excellent morphological definition. As for vascular structures, only the blood flowing inside vessels can be highlighted, while vessels' wall remains mostly invisible. Image segmentation and three-dimensional-printing technology can be used to create physical replica of patient-specific anatomy, to be used for the training of novice surgeons in robotic surgery. To this aim, it is fundamental that the model correctly resembles the morphological properties of the structure of interest, especially concerning vessels on which crucial operations are performed during the intervention. To reach the goal, vessels' actual size must be restored, including information on their wall. Starting from the correlation between vessels' lumen diameter and their wall thickness, we developed a semi-automatic approach to compute the local vessels' wall, bringing the vascular structures as close as possible to their actual size. The optimized virtual models are suitable for manufacturing by means of three-dimensional-printing technology to build patient-specific phantoms for the surgical simulation of robotic abdominal interventions. The proposed approach can effectively lead to the generation of vascular models of optimized thickness wall. The feasibility of the approach is also tested on a selection of clinical cases in abdominal surgery, on which the robotic surgery is performed on the three-dimensional-printed replica before the actual intervention.

A compliant aortic model for in vitro simulations: Design and manufacturing process

We design and manufacture a silicone model of the human aorta, able to mimic both the geometrical and the mechanical properties of physiological individuals, with a specific focus on reproducing the compliance. In fact, while the models available in the literature exhibit an unrealistic compliant behavior, though they are detailed from the geometrical viewpoint, here the goal is to provide an accurate compliant tool for in vitro testing the devices that interface with the vascular system. A parametric design of the aortic model is obtained based on the available literature data, and the model is manufactured with a specific silicone mixture using rapid prototyping and molding techniques. The manufactured prototype has been tested by means of computed tomography scans for evaluating the matching of the mechanical properties with the desired ones. Results show a high degree of adherence between the imposed and the measured compliance values for each main aortic section. Thus, our work proves the feasibility of the approach, and the possibility to manufacture compliant models that reproduce the mechanical behavior of the aorta for in vitro studies.

Additive manufacturing applications in orthopaedics: A review

The applications of Additive Manufacturing (AM) have increased extensively in the area of orthopaedics. The AM applications are for making anatomic models, surgical instruments & tool design, splints, implants and prosthesis. A brief review of various research articles shows that patient-specific orthopaedic procedures provide multiple applications areas and provide directions for future developments. The purpose of this paper is to identify the best possible usage of additive manufacturing applications in orthopaedics field. It also presents the steps used to prepare a 3D printed model by using this technology and details applications in the field of orthopaedics. AM gives a flexible solution in orthopaedics area, where customised implants can be formed as per the required shape and size and can help substitution with customised products. A 3D model created by this technology gain an accurate perception of patient's anatomy which is used to perform mock surgeries and is helpful for highly complex surgical pathologies. It makes surgeon's job accessible and increases the success rate of the operation. AM provides a perfect fit implant for the specific patient by unlimited geometric freedom. Various scanning technologies capture the status of bone defects, and printing of the model is done with the help of this technology. It gives an exact generation of a physical model which is also helpful for medical education, surgical planning and training. This technology can help to solve present-day challenges as data of every patient is different from another.

Systematic Review of the Use of 3-Dimensional Printing in Surgical Teaching and Assessment

OBJECTIVE

The use of 3-dimensional (3D) printing in medicine has rapidly expanded in recent years as the technology has developed. The potential uses of 3D printing are manifold. This article provides a systematic review of the uses of 3D printing within surgical training and assessment.

METHODS

A structured literature search of the major literature databases was performed in adherence to PRISMA guidelines. Articles that met predefined inclusion and exclusion criteria were appraised with respect to the key objectives of the review and sources of bias were analysed.

RESULTS

Overall, 49 studies were identified for inclusion in the qualitative analysis. Heterogeneity in study design and outcome measures used prohibited meaningful meta-analysis. 3D printing has been used in surgical training across a broad range of specialities but most commonly in neurosurgery and otorhinolaryngology. Both objective and subjective outcome measures have been studied, demonstrating the usage of 3D printed models in training and education. 3D printing has also been used in anatomical education and preoperative planning, demonstrating improved outcomes when compared to traditional educational methods and improved patient outcomes, respectively.

CONCLUSIONS

3D printing technology has a broad range of potential applications within surgical education and training. Although the field is still in its relative infancy, several studies have already demonstrated its usage both instead of and in addition to traditional educational methods.

Change, Connectivity, and Challenge: Exploring the Role of Health Technology in Shaping Health Care for Aging Populations in Asia Pacific

Aflthough the rapid increase in population aging observed across the globe poses significant challenges to the sustainability of health systems it has been paralleled by an exponential growth in health technologies. This article reviews the literature surrounding health technologies and explores how the future of aging and health care could be shaped by health technologies, with a particular focus on the Asia Pacific region. It shows that the field is wide in scope. The current expansion of information and communication technologies have brought a growing capacity to support health care, while future technology applications, such as robotics and 3D printing, offer a range of potential benefits to elderly populations. However, the uptake and level of development of health technologies varies widely throughout the region. Governments have begun developing frameworks to guide the implementation and monitoring of health technologies. However, a dearth of robust, evaluative studies, combined with the rapidly evolving nature of health technologies, present policy makers with a range of policy and implementation challenges, including issues surrounding infrastructure, funding, and the acceptability of technologies among older users. As health technologies play an increasingly pivotal part in health systems, there is a need to create robust mechanisms for ongoing assessment of health technology development.

Recommendations regarding splenectomy in hereditary hemolytic anemias

Hereditary hemolytic anemias are a group of disorders with a variety of causes, including red cell membrane defects, red blood cell enzyme disorders, congenital dyserythropoietic anemias, thalassemia syndromes and hemoglobinopathies. As damaged red blood cells passing through the red pulp of the spleen are removed by splenic macrophages, splenectomy is one possible therapeutic approach to the management of severely affected patients. However, except for hereditary spherocytosis for which the effectiveness of splenectomy has been well documented, the efficacy of splenectomy in other anemias within this group has yet to be determined and there are concerns regarding short- and long-term infectious and thrombotic complications. In light of the priorities identified by the European Hematology Association Roadmap we generated specific recommendations for each disorder, except thalassemia syndromes for which there are other, recent guidelines. Our recommendations are intended to enable clinicians to achieve better informed decisions on disease management by splenectomy, on the type of splenectomy and the possible consequences. As no randomized clinical trials, case control or cohort studies regarding splenectomy in these disorders were found in the literature, recommendations for each disease were based on expert opinion and were subsequently critically revised and modified by the Splenectomy in Rare Anemias Study Group, which includes hematologists caring for both adults and children.

A three-dimensional pelvic model made with a three-dimensional printer: applications for laparoscopic surgery to treat rectal cancer

To help understand the three-dimensional (3D) spatial relationships among the highly complex structures of the pelvis, we made a novel 3D pelvic model with a 3D printing system. We created two pelvic models including the muscles, vessels, nerves, and urogenital organs; the first based on the pelvic anatomy of a healthy male volunteer and the second on the pelvic anatomy of a female volunteer with rectal cancer. The models clearly demonstrated the complicated spatial relationships between anatomical structures in the pelvis. Surgeons could use these models to improve their spatial understanding of pelvic anatomy, which could consequently improve the safety and efficiency of laparoscopic rectal cancer surgery.

3D printing: clinical applications in orthopaedics and traumatology

Advances in image processing have led to the clinical use of 3D printing technology, giving the surgeon a realistic physical model of the anatomy upon which he or she will operate.

Relying on CT images, the surgeon creates a virtual 3D model of the target anatomy from a series of bi-dimensional images, translating the information contained in CT images into a more usable format.

3D printed models can play a central role in surgical planning and in the training of novice surgeons, as well as reducing the rate of re-operation.

Cite this article: Auricchio F, Marconi S. 3D printing: clinical applications in orthopaedics and traumatology. EFORT Open Rev 2016;1:121–127. DOI: 10.1302/2058-5241.1.000012.

The use of three-dimensional printing technology in orthopaedic surgery

Three-dimensional (3-D) printing or additive manufacturing, an advanced technology that 3-D physical models are created, has been wildly applied in medical industries, including cardiothoracic surgery, cranio-maxillo-facial surgery and orthopaedic surgery. The physical models made by 3-D printing technology give surgeons a realistic impression of complex structures, allowing surgical planning and simulation before operations. In orthopaedic surgery, this technique is mainly applied in surgical planning especially revision and reconstructive surgeries, making patient-specific instruments or implants, and bone tissue engineering. This article reviews this technology and its application in orthopaedic surgery.

Designing Biomaterials for 3D Printing

Three-dimensional (3D) printing is becoming an increasingly common technique to fabricate scaffolds and devices for tissue engineering applications. This is due to the potential of 3D printing to provide patient-specific designs, high structural complexity, rapid on-demand fabrication at a low-cost. One of the major bottlenecks that limits the widespread acceptance of 3D printing in biomanufacturing is the lack of diversity in "biomaterial inks". Printability of a biomaterial is determined by the printing technique. Although a wide range of biomaterial inks including polymers, ceramics, hydrogels and composites have been developed, the field is still struggling with processing of these materials into self-supporting devices with tunable mechanics, degradation, and bioactivity. This review aims to highlight the past and recent advances in biomaterial ink development and design considerations moving forward. A brief overview of 3D printing technologies focusing on ink design parameters is also included.

3D bioprinting for engineering complex tissues

Bioprinting is a 3D fabrication technology used to precisely dispense cell-laden biomaterials for the construction of complex 3D functional living tissues or artificial organs. While still in its early stages, bioprinting strategies have demonstrated their potential use in regenerative medicine to generate a variety of transplantable tissues, including skin, cartilage, and bone. However, current bioprinting approaches still have technical challenges in terms of high-resolution cell deposition, controlled cell distributions, vascularization, and innervation within complex 3D tissues. While no one-size-fits-all approach to bioprinting has emerged, it remains an on-demand, versatile fabrication technique that may address the growing organ shortage as well as provide a high-throughput method for cell patterning at the micrometer scale for broad biomedical engineering applications. In this review, we introduce the basic principles, materials, integration strategies and applications of bioprinting. We also discuss the recent developments, current challenges and future prospects of 3D bioprinting for engineering complex tissues. Combined with recent advances in human pluripotent stem cell technologies, 3D-bioprinted tissue models could serve as an enabling platform for high-throughput predictive drug screening and more effective regenerative therapies.

Streamlined, Inexpensive 3D Printing of the Brain and Skull

Neuroimaging technologies such as Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) collect three-dimensional data (3D) that is typically viewed on two-dimensional (2D) screens. Actual 3D models, however, allow interaction with real objects such as implantable electrode grids, potentially improving patient specific neurosurgical planning and personalized clinical education. Desktop 3D printers can now produce relatively inexpensive, good quality prints. We describe our process for reliably generating life-sized 3D brain prints from MRIs and 3D skull prints from CTs. We have integrated a standardized, primarily open-source process for 3D printing brains and skulls. We describe how to convert clinical neuroimaging Digital Imaging and Communications in Medicine (DICOM) images to stereolithography (STL) files, a common 3D object file format that can be sent to 3D printing services. We additionally share how to convert these STL files to machine instruction gcode files, for reliable in-house printing on desktop, open-source 3D printers. We have successfully printed over 19 patient brain hemispheres from 7 patients on two different open-source desktop 3D printers. Each brain hemisphere costs approximately $3–4 in consumable plastic filament as described, and the total process takes 14–17 hours, almost all of which is unsupervised (preprocessing = 4–6 hr; printing = 9–11 hr, post-processing = <30 min). Printing a matching portion of a skull costs $1–5 in consumable plastic filament and takes less than 14 hr, in total. We have developed a streamlined, cost-effective process for 3D printing brain and skull models. We surveyed healthcare providers and patients who confirmed that rapid-prototype patient specific 3D models may help interdisciplinary surgical planning and patient education. The methods we describe can be applied for other clinical, research, and educational purposes.