The impact of 3D reconstruction technology on liver surgery in changing the pathway of surgical maneuvers: A case report.

INTRODUCTION: This case report illustrates the significant role that 3D technology can play in major hepatic surgery, aiding in the determination of the optimal surgical approach. CASE PRESENTATION: We present the case of a patient with metachronous liver metastasis from rectal cancer involving segments 6 and 7, extending to retroperitoneal structures such as the inferior vena cava (IVC) and the right renal vein (RRV). DISCUSSION: After confirming the feasibility of a right hepatectomy, we opted for a traditional posterior approach, avoiding the hanging maneuver. The 3D rendering was instrumental in this decision, revealing that the mass was in close proximity to the IVC at the 11 o'clock position, a critical area for surgical instruments during the hanging maneuver. CONCLUSION: When 2D imaging fails to provide sufficient information, 3D rendering can substantially aid the decision-making process.

Atlantoaxial joint stabilization using patient-specific 3-D-printed drill guides and 3-D-printed titanium plates or polymethyl methacrylate is effective in toy-breed dogs.

OBJECTIVE: To report the clinical outcomes in toy-breed dogs with atlantoaxial instability (AAI) stabilized with patient-specific 3-D-printed titanium plates or polymethyl methacrylate (PMMA), both with the assistance of 3-D-printed drill guides. ANIMALS: 15 client-owned dogs undergoing surgical treatment for AAI between January 1, 2020, and October 31, 2022. METHODS: The clinical characteristics, diagnostic images, and neurological outcomes of 15 dogs treated for AAI using 3-D-printing technology were reviewed. Postoperative CT images were examined to evaluate the screw placement accuracy in the atlas and axis. Clinical outcomes, including postoperative neurological improvement and screw loosening, were evaluated in dogs treated with a patient-specific titanium plate and those treated with PMMA. RESULTS: Patient-specific titanium plates (7 dogs) and PMMA (8 dogs) were used for AAI stabilization. The mean follow-up period was 15.2 months (range 7 to 22 months). A reduction of the axis without vertebral canal violation was confirmed on postoperative CT in 14 dogs. The mean deviation from the preoperative planning ranged from 0.30 to 1.27 mm at the insertion and exit points of 84 screws using this method. The neurological grade had improved in each dog postoperatively and at the final follow-up. Screw loosening was noted in 4 dogs in the titanium plates groups without neurological deterioration. CLINICAL RELEVANCE: Patient-specific 3-D-printed drill guides and titanium plates or PMMA are effective for AAI stabilization in toy-breed dogs, providing accurate guidance.

3D printed orthopedic prostheses for domestic and wild birds-case reports.

Regardless of the species, birds are exposed to injuries that lead to amputation of part of the body structure and often euthanasia. Based on the need for new technologies that improve the quality of life of birds with locomotor problems, the present case reports aimed to describe the development of custom-made three-dimensional (3D) prostheses for domestic and wild birds that suffered amputation or malformation of the hind limb. Using the measurements of the bird, a digital model was created for 3D printing using fused deposition modeling technology (FDM) by the Brazilian company 3D Medicine. In this study we report the use of 3D prosthesis for the rehabilitation of three birds with locomotor disorders in Brazil, the animals adapted to the custom-made prosthesis with an improvement in quality of life, better distribution of body weight, locomotion, and landing. This study describes the development of 3D prostheses for birds in Brazil, the first report of this technology for these species, and the pioneering development of socket prostheses for small birds. 3D prostheses offer a high-efficiency solution to improve the quality of life of animals with amputations and malformations of the hind limbs. In addition, 3D technology provides valuable tools for veterinary medicine, developing custom-made models for the most different anatomical demands of animal patients.

3D-assisted corrective osteotomies of the distal radius: a comparison of pre-contoured conventional implants versus patient-specific implants.

PURPOSE: There is a debate whether corrective osteotomies of the distal radius should be performed using a 3D work-up with pre-contoured conventional implants (i.e., of-the-shelf) or patient-specific implants (i.e., custom-made). This study aims to assess the postoperative accuracy of 3D-assisted correction osteotomy of the distal radius using either implant. METHODS: Twenty corrective osteotomies of the distal radius were planned using 3D technologies and performed on Thiel embalmed human cadavers. Our workflow consisted of virtual surgical planning and 3D printed guides for osteotomy and repositioning. Subsequently, left radii were fixated with patient-specific implants, and right radii were fixated with pre-contoured conventional implants. The accuracy of the corrections was assessed through measurement of rotation, dorsal and radial angulation and translations with postoperative CT scans in comparison to their preoperative virtual plan. RESULTS: Twenty corrective osteotomies were executed according to their plan. The median differences between the preoperative plan and postoperative results were 2.6° (IQR: 1.6-3.9°) for rotation, 1.4° (IQR: 0.6-2.9°) for dorsal angulation, 4.7° (IQR: 2.9-5.7°) for radial angulation, and 2.4 mm (IQR: 1.3-2.9 mm) for translation of the distal radius, thus sufficient for application in clinical practice. There was no significant difference in accuracy of correction when comparing pre-contoured conventional implants with patient-specific implants. CONCLUSION: 3D-assisted corrective osteotomy of the distal radius with either pre-contoured conventional implants or patient-specific implants results in accurate corrections. The choice of implant type should not solely depend on accuracy of the correction, but also be based on other considerations like the availability of resources and the preoperative assessment of implant fitting.

Brain organoids for hypoxic-ischemic studies: from bench to bedside.

Our current knowledge regarding the development of the human brain mostly derives from experimental studies on non-human primates, sheep, and rodents. However, these studies may not completely simulate all the features of human brain development as a result of species differences and variations in pre- and postnatal brain maturation. Therefore, it is important to supplement the in vivo animal models to increase the possibility that preclinical studies have appropriate relevance for potential future human trials. Three-dimensional brain organoid culture technology could complement in vivo animal studies to enhance the translatability of the preclinical animal studies and the understanding of brain-related disorders. In this review, we focus on the development of a model of hypoxic-ischemic (HI) brain injury using human brain organoids to complement the translation from animal experiments to human pathophysiology. We also discuss how the development of these tools provides potential opportunities to study fundamental aspects of the pathophysiology of HI-related brain injury including differences in the responses between males and females.

Perception and knowledge of learners about the use of 3D technologies in manual therapy education - a qualitative study.

OBJECTIVES: Manual therapy is a specific hands-on approach used and taught by various professions such as physiotherapy and osteopathy. The current paradigm of teaching manual therapy incorporates the traditional 'See one, do one, teach one' approach. However, this 'teacher centred' approach may not enable learners to develop the complex clinical skills of manual therapy. In this context, 3D technologies such as virtual reality may facilitate the teaching and learning of manual therapy. Hence the aim of the current study was to investigate the perception, knowledge and attitude of manual therapy learners about the use of 3D technologies in manual therapy education. METHODS: An exploratory qualitative research design using semi-structured interviews was used in this study. A total of ten manual therapy (5 physiotherapy and 5 osteopathic) students (mean age = 32; 80% female) enrolled in an appropriate physiotherapy or osteopathic degree provided by a New Zealand recognized institution (e.g., university or polytechnic) participated in this study. Data saturation was achieved after 10 interviews (average duration: 35 min) that provided thick data. A thematic analysis was used for data analysis. RESULTS: Six factors were identified which appeared to influence participants' perception of role of technology in manual therapy education. These were (1) the sufficiency of current teaching method; (2) evolution as a learner (a novice to an expert); (3) need for objectivity; (4) tutor feedback; (5) knowledge and (6) barriers and enablers. These six factors influenced the participants' perception about the role of 3D technologies in manual therapy education with participants evidently taking two distinct/polarized positions ('no role' (techstatic) versus a 'complete role' (techsavvy)). CONCLUSION: Although 3D technology may not replace face-to-face teaching, it may be used to complement the traditional approach of learning/teaching to facilitate the learning of complex skills according to the perceptions of manual therapy learners in our study. The advantage of such an approach is an area of future research.

[The role of 3D technology in the support of mechanical circulation therapy.] / A 3D technológia szerepe a muszívterápiában.

INTRODUCTION: Successful mechanical circulatory support is influenced by various factors, which are difficult or impossible to control. For ideal functioning of the left ventricular assist device inflow-cannula, its axis should be close to parallel with the septum, facing the mitral valve within the left ventricle. Numerous international publications discuss that deviation from optimal implantation can lead to inadequate functioning and serious complications. OBJECTIVE: Our objective was to developing a method, which, using 3D technology, anatomical and hydrodynamic data, makes optimal surgical implantation of the left ventricular assist device possible. METHOD: Data of 57 patients, receiving mechanical circulatory support at Semmelweis University, Heart and Vascular Center, were analyzed retrospectively. Results of operations performed with the patented novel navigation device (exoskeleton) were compared with results of operations performed conventionally, without navigation (control group). Following pairing based on estimated participation probability, postoperative data of 7-7 patients were compared. DICOM files from CT angiography images were used to create virtual geometries of individual hearts. Optimal inflow-cannula angle was determined through hydrodynamic simulation. Exoskeletons were printed using synthetic resin suitable for surgical purposes. Exoskeleton templates guided punch knife positioning and inflow-cannula implantation. RESULTS: Evaluation of postoperative CT angiography images showed that the angle between inflow-cannula and interventricular septum significantly differed in the exoskeleton and control groups (10.13° ± 2.69° vs. 22.87° ± 12.38°, p = 0.0208). Hydrodynamic tests found significantly lower turbulence in the exoskeleton group. Simulated turbulent kinetic energy was significantly lower in the exoskeleton group, which was 11.7 m2/s2 ± 9.39 m2/s2 vs. 49.59 m2/s2 ± 7.61 m2/s2 on average. CONCLUSION: The results suggest left ventricular assist device implantation with patented exoskeleton to be a standardizable, safe and effective method. Preliminary results suggest, that the method may facilitate individualized care, reduce surgical time and incidence of serious complications. Orv Hetil. 2023; 164(26): 1026-1033.

In-office Customized Brackets: Aligning with the Future.

Digital technology introduced many innovations in the field of dentistry and orthodontics in the last years. The most important advancement was the ability to digitize the oral cavity using intraoral scanners. CAD software have been around for decades, but only in the last twenty years started showing up in the field of dentistry and orthodontics. 3D printers are not new in the field of manufacturing. Nevertheless, their inclusion in the orthodontist armamentarium was made possible only the last few years, while new printing materials have been also invented, allowing the manufacturing of many appliances previously made using traditional laboratory procedures. Orthodontic treatment is mainly based on the use of fixed appliances. The vast majority of orthodontists use commercial straight-wire brackets while customized brackets are preferred mostly for lingual orthodontic treatment. New CAD software called Ubrackets allows the in-office designing and printing of customized brackets using hybrid ceramic crown resin or zirconia slurry. Some scientific studies have been conducted to investigate the bracket printing outcome in terms of mechanical properties. More studies must be performed to allow the inclusion of in-office designing and printing of customized brackets in the orthodontic armamentarium.

Views on Augmented Reality, Virtual Reality, and 3D Printing in Modern Medicine and Education: A Qualitative Exploration of Expert Opinion.

Although an increased usage and development of 3D technologies is observed in healthcare over the last decades, full integration of these technologies remains challenging. The goal of this project is to qualitatively explore challenges, pearls, and pitfalls of AR/VR/3D printing applications usage in the medical field of a university medical center. Two rounds of face-to-face interviews were conducted using a semi-structured protocol. First an explorative round was held, interviewing medical specialists (8), PhD students (7), 3D technology specialists (5), and university teachers (3). In the second round, twenty employees in high executive functions of relevant departments were interviewed on seven statements that resulted from the first interviewing round. Data analysis was performed using direct content analyses. The first interviewing round resulted in challenges and opportunities in 3D technology usage that were grouped in 5 themes: aims of using AR/VR/3D printing (1), data acquisition (2), data management plans (3), software packages and segmentation tools (4), and output data and reaching end-user (5). The second interviewing round resulted in an overview of ideas and insights on centralization of knowledge, improving implementation of 3D technology in daily healthcare, reimbursement of 3D technologies, recommendations for further studies, and requirement of using certified software. An overview of challenges and opportunities of 3D technologies in healthcare was provided. Well-designed studies on clinical effectiveness, implementation and cost-effectiveness are warranted for further implementation into the clinical setting.

Directly Printed Aligner: Aligning with the Future.

Orthodontics stands on a junction where traditional analog appliance manufacturing slowly but steadily changes to a digital one with the use of 3D technology. The main cause of this shift was the invention and use of computers. The use of computers, computer-aided design (CAD) software, computerized machines, and newly invented materials allowed this change to occur in a relatively short time in dentistry and orthodontics. The trigger for this transformation is the ability to digitally scan the oral cavity. CAD software and 3D printers already existed. It took a few years to include this technology in orthodontics and continuously apply it in the orthodontic office. Orthodontic treatment is mainly based on the use of fixed appliances, while in the last years, thermoformed aligners have been introduced as an alternative whenever a more invisible treatment modality is preferred. Clear aligner treatment is performed using thermoformed aligner. A new aligner resin has been recently invented to allow direct aligner printing. Directly printed aligner possess many advantages compared to thermoformed one. Research has been initiated to investigate all the aspects of the workflow and aligner printing outcome. More studies must be performed to look into the various aspects of directly printed aligners.

How students discern anatomical structures using digital three-dimensional visualizations in anatomy education.

Learning anatomy holds specific challenges, like the appreciation of three-dimensional relationships between anatomical structures. So far, there is limited knowledge about how students construct their understanding of topographic anatomy. By understanding the processes by which students learn anatomical structures in 3D, educators will be better equipped to offer support and create successful learning situations. Using video analysis, this study investigates how students discern anatomical structures. Sixteen students at different levels of education and from different study programs were recorded audiovisually while exploring 3D digital images using a computerized visualization table. Eleven hours of recorded material were analyzed using interaction analysis and phenomenography. Seven categories were identified during data analysis, describing the qualitatively different patterns of actions that students use to make sense of anatomy: decoding the image; positioning the body in space; purposeful seeking, using knowledge and experience; making use of and creating variation; aimless exploration, and arriving at moments of understanding. The results suggest that anatomy instruction should be organized to let the students decide how and at what pace they examine visualized images. Particularly, the discovery process of decoding and positioning the body in space supports a deep learning approach for learning anatomy using visualizations. The students' activities should be facilitated and not directed.

Three-dimensional technologies in chest wall resection and reconstruction.

Resection and reconstruction of the chest wall can pose unique challenges given its vital role in the protection of the thoracic viscera and the dynamic part it plays in respiration. A number of new three-dimensional (3D) technologies may be invaluable in tackling these challenges. Herein we review the use of 3D technologies in preoperative imaging with virtual 3D models, printing of 3D models for preoperative planning, and printing of 3D prostheses when approaching complex chest wall reconstruction.

Vision therapy system 4D combined with stereoscopic 3D training technology for the treatment of amblyopia / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate the effect of vision therapy system 4D combined with stereoscopic 3D technology training for the treatment of amblyopia.METHODS: Prospective study. A total of 102 children with amblyopia who attended the clinic from January 2018 to January 2022 were selected, and they were randomly assigned into two groups by computer, with 51 cases in each group. Control group received stereoscopic 3D technology training, while observation group participated in vision therapy system 4D on the basis of control group. Then the overall effective rate, binocular visual function, spherical equivalent(SE), axial length(AL), mean corneal curvature(Km), best corrected visual acuity(BCVA)and visual evoked potential were compared between two groups.RESULTS: The overall efficacy rate was 94.1% in observation group, which was obviously higher than control group(74.5%; P<0.05). The improvement in binocular vision parameters simultaneous perception, total fusion, and stereoacuity were all more remarkable in observation group than in control group(P<0.05). The △SE, △AL and △Km yielded no statistical difference between two groups(P>0.05). The latency of two spatial frequencies(1°grid and 15'grid)showed a decline in both groups, and the decline was more notable in observation group than in control group(P<0.05). In both groups, BCVA improved, and the improvement was more significant in observation group compared with control group(P<0.05).CONCLUSION: Application of vision therapy system 4D combined with stereoscopic 3D technology training for amblyopia can effectively ameliorate the visual acuity, promote the reconstruction of simultaneous perception, total fusion, and stereoacuity without additional risk of myopic shift, and improve visual pathway function in children.

Osseous Union after Jaw Reconstruction with Fibula-Free Flap: Conventional vs. CAD/CAM Patient-Specific Implants.

This is a monocentric, retrospective study of patients who underwent successful immediate or delayed maxilla or mandible reconstructions with FFF from January 2005 to December 2021. Panoramic radiograph, computed tomography scans, and cone-beam CTs were analyzed concerning the osseous union of the intersegmental junctions between maxillary or mandibular native jaw and fibular bone. The primary parameter was to estimate the status of osseous union according to osteosynthesis type. A total number of 133 patients (PSI: n = 64, non-PSI: n = 69) were included in the present study. The mean age was 56.7 ± 14.0 (Range: 14.7−82.7); the primary diagnosis was in 105 patients a malignant (78.9%) and in 20 patients a benign (15.0%) tumor. Mandible reconstruction was performed on 103 patients (77.4%), and on 30 patients (22.6%), maxilla reconstruction was performed. The radiographic images provided a rate of incomplete osseous union (IOU) of about 90% in both groups in the first 6 months. Imaging between 6 and 12 months reveals an IOU rate in the non-PSI group of 46.3% vs. 52.5% in the PSI group, between 12 and 24 months, an IOU rate of 19.6% vs. 26.1%, between 24 and 36 months 8.9% vs. 21.7%, and after 36 months the IOU rate decreases to 4.2% vs. 18.2%. Multivariate logistic regression shows that only osteosynthesis type (OR = 3.518 [95%-CI = 1.223−10.124], p = 0.02) and adjuvant radiotherapy (OR = 4.804 [95%-CI = 1.602−14.409], p = 0.005) are independent risk factors for incomplete osseous union. Cox regression revealed that the variables plate-system (Hazard ratio, HR = 5.014; 95 %-CI: 1.826−3.769; p = 0.002) and adjuvant radiotherapy (HR = 5.710; 95 %-CI: 2.066−15.787; p < 0.001) are predictors for incomplete osseous union. In our study, the rate of incomplete bony fusion was significantly higher in the PSI group. Jaw-to-fibula apposition zones were significantly more affected than intersegmental zones. In multivariate analysis, a combination of osteosynthesis with PSI and adjuvant radiotherapy could be identified as a risk constellation for incomplete ossification.

Three-dimensional exoscope-assisted single-stage tracheal resection.

The three-dimensional (3D) 4K exoscope is a surgical tool recently introduced in numerous fields of otolaryngology, such as microvascular surgery, otology, and laryngology. However, other surgical fields may also benefit from this technology. In this case, a single-stage tracheal resection was planned with the aid of the 3D 4K exoscope, in a 75-year-old female with post-tracheostomy tracheal stenosis. High-quality magnification of the surgical field was obtained, with facilitated skeletonization of the laryngotracheal axis. The exoscope provided greater involvement in surgery and allowed more interactions among all operating room personnel and learners, as they could access the same field of view of the first surgeon, as well as perceiving depth of the surgical field with 3D technology. The exoscope represents a valid application in open surgery performed for laryngotracheal stenosis, with advantages of enhancing training and education, allowing precise surgical dissection, and reducing risks of iatrogenic damage to surrounding structures.

A Two-Step Approach for 3D-Guided Patient-Specific Corrective Limb Osteotomies.

Background: Corrective osteotomy surgery for long bone anomalies can be very challenging since deformation of the bone is often present in three dimensions. We developed a two-step approach for 3D-planned corrective osteotomies which consists of a cutting and reposition guide in combination with a conventional osteosynthesis plate. This study aimed to assess accuracy of the achieved corrections using this two-step technique. Methods: All patients (≥12 years) treated for post-traumatic malunion with a two-step 3D-planned corrective osteotomy within our center in 2021 were prospectively included. Three-dimensional virtual models of the planned outcome and the clinically achieved outcome were obtained and aligned. Postoperative evaluation of the accuracy of performed corrections was assessed by measuring the preoperative and postoperative alignment error in terms of angulation, rotation and translation. Results: A total of 10 patients were included. All corrective osteotomies were performed according to the predetermined surgical plan without any complications. The preoperative deformities ranged from 7.1 to 27.5° in terms of angulation and 5.3 to 26.1° in terms of rotation. The achieved alignment deviated on average 2.1 ± 1.0 and 3.4 ± 1.6 degrees from the planning for the angulation and rotation, respectively. Conclusions: A two-step approach for 3D-guided patient-specific corrective limb osteotomies is reliable, feasible and accurate.

3D bioprinting as an emerging standard for cancer modeling and drug testing.

Neoplastic diseases are a leading cause of death worldwide accounting for 10 million mortalities in 2020. Despite constantly revised and improved therapeutic regimens, the number of fatal cases increases annually. Therefore, better preclinical models are needed to study tumorigenesis and assess new drugs. Although 2D cell cultures significantly contributed to the understanding of tumor biology, they present high clinical trial failure rates. This is because 2D cannot reproduce the intricate tumor architecture and multiple cell interactions.Nevertheless, novel 3D biofabrication technologies and 3D bioprinted tumor models successfully mirror the complexity of human tumors and are currently revolutionizing preclinical cancer research by using live cells encapsulated in a variety of biomaterials. Since bioinks possess excellent chemical and biophysical ECM-like characteristics, this allows for recreation of the intricate tumor-specific architecture with an unmatched level of control, accuracy, and reproducibility. The resulting cellular constructs approximate actual pathological microenvironment of the tumor and some key in vivo processes such as proliferation, differentiation, and metastasis. 3D bioprinted models of glioblastoma, cervical, ovarian, and breast cancer are already being successfully used to study tumorigenesis and cellular response to antitumor drugs. This success showcases the potential of these novel experimental platforms.

Fully Digitalized Workflow for One-Stage Mandibular Contouring and Orthognathic Surgery to Correct Severe Facial Asymmetry.

INTRODUCTION: Surgical correction of facial asymmetry is commonly performed in at least two stages. Recently, because of the long duration of a two-step procedure, the demand for a one-step procedure has increased. Our study aims to present a fully digitalized workflow for one-stage mandibular contouring (MC) and bimaxillary surgery to correct severe facial asymmetry using 3D technology. MATERIALS AND METHODS: A retrospective monocentric study was conducted for all patients affected by severe facial asymmetry who had undergone MC and orthognathic surgery between January 2018 and June 2020 at the Face Surgery Center, in Parma, Italy. RESULTS: The final study sample included 20 patients (12 women and 8 men). The mean age of the patients at the time of surgery was 20.8 years (range: 18-25 years). At the one-year follow-up, all patients had stable occlusion with a symmetric face. Mandibular angle degree (Ar-Go-Me) increased significantly from 113. 6° to 122.7° at the left side and from 113.3° to 122.7° at the right side (p < 0.05) (Table 1). The mandibular width (Go-Go) decreased from 116.5 to 106.4 mm (p < 0.05). CONCLUSION: A fully digitalized workflow for one-stage MC and bimaxillary surgery is a safe and valid option to correct facial asymmetry. CAD CAM technology is an indispensable tool to obtain predictable results. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Restoration in Vertebral Compression Fractures (VCF): Effectiveness Evaluation Based on 3D Technology.

There are few studies about anatomical reduction of the fractured vertebral body before stabilization for treatment of vertebral compression fracture (VCF). Although restoration on vertebral height has been useful, the reduction of fractured endplates is limited. The vertebra is part of a joint, and vertebral endplates must be treated like other weight-bearing joint to avoid complications. The aim of this study was to evaluate the feasibility of anatomic reduction of vertebral compression fracture, in different bone conditions, fracture types, and ages (VCF). Under methodological point of view, we followed different steps: first was the placement of two expandable titanium implants just below the fracture. Later, to push the fractured endplates into a more anatomical position, the implants were expanded. Finally, with the implants perfectly positioned, PMMA cement was injected to avoid any loss of correction. To evaluate the effectiveness of this procedure in anatomical fracture reduction, a method based on 3D CT reconstructions was developed. In this paper, we have developed the procedure in three case studies. In all of them, we were able to demonstrate the efficacy of this procedure to reduce the VCF. The percentage of correction of the kyphotic angle varied range between 49% and 62% with respect to the value after the fracture preoperative value. This was accompanied by a reduction of the pain level on the VAS scale around 50%. In conclusion, this novel approach to the vertebral fracture treatment (VCF) associated with 3D assessment have demonstrated the possibility of reducing the vertebral kyphosis angle and the vertebral endplate fractures. However, given the few cases presented, more studies are necessaries to confirm these results.