Three-dimensional printing to facilitate anatomic study, device development, simulation, and planning in thoracic surgery

Post-printing processing and aging effects on Polyjet materials intended for the fabrication of advanced surgical simulators

Material Jetting (MJ) 3D printing technology is promising for the fabrication of highly realistic surgical simulators, however, the changes in the mechanical properties of MJ materials after post-printing treatments and over time remain quite unknown. In this study, we investigate the effect of different post-printing processes and aging on the mechanical properties of a white opaque and rigid MJ photopolymer, a white flexible MJ photopolymer and on a combination of them. Tensile and Shore hardness tests were conducted on homogeneous 3D-printed specimens: two different post-printing procedures for support removal (dry and water) and further surface treatment (with glycerol solution) were compared. The specimens were tested within 48 h from printing and after aging (30-180 days) in a controlled environment. All groups of specimens treated with different post-printing processes (dry, water, glycerol) exhibited a statistically significant difference in mechanical properties (i.e. elongation at break, elastic modulus, ultimate tensile strength). Particularly, the treatment with glycerol makes the flexible photopolymer more rigid, but then with aging the initial elongation of the material tends to be restored. For the rigid photopolymer, an increase in deformability was observed as a major effect of aging. The hardness tests on the printed specimens highlighted a significant overestimation of the Shore values declared by the manufacturer. The study findings are useful for guiding the material selection and post-printing processing techniques to manufacture realistic and durable models for surgical training.

3D Printing for Cardiovascular Surgery and Intervention: A Review Article

3D printing technology can be applied to practically every aspect of modern life, fulfilling the needs of people from various backgrounds. The utilization of 3D printing in the context of adult heart disease can be succinctly categorized into 3 primary domains: preoperative strategizing or simulation, medical instruction, and clinical consultations. 3D-printed model utilization improves surgical planning and intraoperative decision-making and minimizes surgical risks, and it has demonstrated its efficacy as an innovative educational tool for aspiring surgeons with limited practical exposure. Despite all the applications of 3D printing, it has not yet been shown to improve long-term outcomes, including safety. There are no data on the outcomes of controlled trials available. To appropriately diagnose heart disease, 3D-printed models of the heart can provide a better understanding of the intracardiac anatomy and provide all the information needed for operative planning. Experientially, 3D printing provides a wide range of perceptions for understanding lower extremity arteries' spatial geometry and anatomical features of pathology. Practicing cardiac surgery processes using objects printed using 3D imaging data can become the norm rather than the exception, leading to improved accuracy and quality of treatment. This study aimed to review the various applications of 3D printing technology in cardiac surgery and intervention.

Influence of Intraoral Scanners, Operators, and Data Processing on Dimensional Accuracy of Dental Casts for Unsupervised Clinical Machine Learning: An In Vitro Comparative Study

Purpose

This study assessed the impact of intraoral scanner type, operator, and data augmentation on the dimensional accuracy of in vitro dental cast digital scans. It also evaluated the validation accuracy of an unsupervised machine-learning model trained with these scans.

Methods

Twenty-two dental casts were scanned using two handheld intraoral scanners and one laboratory scanner, resulting in 110 3D cast scans across five independent groups. The scans underwent uniform augmentation and were validated using Hausdorff's distance (HD) and root mean squared error (RMSE), with the laboratory scanner as reference. A 3-factor analysis of variance examined interactions between scanners, operators, and augmentation methods. Scans were divided into training and validation sets and processed through a pretrained 3D visual transformer, and validation accuracy was assessed for each of the five groups.

Results

No significant differences in HD and RMSE were found across handheld scanners and operators. However, significant changes in RMSE were observed between native and augmented scans with no specific interaction between scanner or operator. The 3D visual transformer achieved 96.2% validation accuracy for differentiating upper and lower scans in the augmented dataset. Native scans lacked volumetric depth, preventing their use for deep learning.

Conclusion

Scanner, operator, and processing method did not significantly affect the dimensional accuracy of 3D scans for unsupervised deep learning. However, data augmentation was crucial for processing intraoral scans in deep learning algorithms, introducing structural differences in the 3D scans. Clinical Significance. The specific type of intraoral scanner or the operator has no substantial influence on the quality of the generated 3D scans, but controlled data augmentation of the native scans is necessary to obtain reliable results with unsupervised deep learning.

Utilizing 3D printing to assist pre-procedure planning of transjugular intrahepatic portosystemic shunt (TIPS) procedures: a pilot study

BACKGROUND

3D (three-dimensional) printing has been adopted by the medical community in several ways, procedure planning being one example. This application of technology has been adopted by several subspecialties including interventional radiology, however the planning of transjugular intrahepatic portosystemic shunt (TIPS) placement has not yet been described. The impact of a 3D printed model on procedural measures such as procedure time, radiation exposure, intravascular contrast dosage, fluoroscopy time, and provider confidence has also not been reported.

METHODS

This pilot study utilized a quasi-experimental design including patients who underwent TIPS. For the control group, retrospective data was collected on patients who received a TIPS prior to Oct 1, 2020. For the experimental group, patient-specific 3D printed models were integrated in the care of patients that received TIPS between Oct 1, 2020 and April 15, 2021. Data was collected on patient demographics and procedural measures. The interventionalists were surveyed on their confidence level and model usage following each procedure in the experimental group.

RESULTS

3D printed models were created for six TIPS. Procedure time (p = 0.93), fluoroscopy time (p = 0.26), and intravascular contrast dosage (p = 0.75) did not have significant difference between groups. Mean radiation exposure was 808.8 mGy in the group with a model compared to 1731.7 mGy without, however this was also not statistically significant (p = 0.09). Out of 11 survey responses from interventionists, 10 reported "increased" or "significantly increased" confidence after reviewing the 3D printed model and all responded that the models were a valuable tool for trainees.

CONCLUSIONS

3D printed models of patient anatomy can consistently be made using consumer-level, desktop 3D printing technology. This study was not adequately powered to measure the impact that including 3D printed models in the planning of TIPS procedures may have on procedural measures. The majority of interventionists reported that patient-specific models were valuable tools for teaching trainees and that confidence levels increased as a result of model inclusion in procedure planning.

Bioengineering and Clinical Translation of Human Lung and its Components

Clinical lung transplantation has rapidly established itself as the gold standard of treatment for end-stage lung diseases in a restricted group of patients since the first successful lung transplant occurred. Although significant progress has been made in lung transplantation, there are still numerous obstacles on the path to clinical success. The development of bioartificial lung grafts using patient-derived cells may serve as an alternative treatment modality; however, challenges include developing appropriate scaffold materials, advanced culture strategies for lung-specific multiple cell populations, and fully matured constructs to ensure increased transplant lifetime following implantation. This review highlights the development of tissue-engineered tracheal and lung equivalents over the past two decades, key problems in lung transplantation in a clinical environment, the advancements made in scaffolds, bioprinting technologies, bioreactors, organoids, and organ-on-a-chip technologies. The review aims to fill the lacuna in existing literature toward a holistic bioartificial lung tissue, including trachea, capillaries, airways, bifurcating bronchioles, lung disease models, and their clinical translation. Herein, the efforts are on bridging the application of lung tissue engineering methods in a clinical environment as it is thought that tissue engineering holds enormous promise for overcoming the challenges associated with the clinical translation of bioengineered human lung and its components.

Percutaneous delivery and degradation of a shape memory elastomer poly(glycerol dodecanedioate) in porcine pulmonary arteries

Shape memory biodegradable elastomers are an emergent class of biomaterials well-suited for percutaneous cardiovascular repair requiring nonlinear elastic materials with facile handling. We have previously developed a chemically crosslinked shape memory elastomer, poly (glycerol dodecanedioate) (PGD), exhibiting tunable transition temperatures around body temperature (34-38 °C), exhibiting nonlinear elastic properties approximating cardiac tissues, and favorable degradation rates in vitro. Degree of tissue coverage, degradation and consequent changes in polymer thermomechanical properties, and inflammatory response in preclinical animal models are unknown material attributes required for translating this material into cardiovascular devices. This study investigates changes in the polymer structure, tissue coverage, endothelialization, and inflammation of percutaneously implanted PGD patches (20 mm × 9 mm x 0.5 mm) into the branch pulmonary arteries of Yorkshire pigs for three months. After three months in vivo, 5/8 samples exhibited (100%) tissue coverage, 2/8 samples exhibited 85-95% tissue coverage, and 1/8 samples exhibited limited (<20%) tissue coverage with mild-moderate inflammation. PGD explants showed a (60-70%) volume loss and (25-30%) mass loss, and a reduction in polymer crosslinks. Lumenal and mural surfaces and the cross-section of the explant demonstrated evidence of degradation. This study validates PGD as an appropriate cardiovascular engineering material due to its propensity for rapid tissue coverage and uneventful inflammatory response in a preclinical animal model, establishing a precedent for consideration in cardiovascular repair applications.

Additive Manufacturing of 3D Anatomical Models-Review of Processes, Materials and Applications

The methods of additive manufacturing of anatomical models are widely used in medical practice, including physician support, education and planning of treatment procedures. The aim of the review was to identify the area of additive manufacturing and the application of anatomical models, imitating both soft and hard tissue. The paper outlines the most commonly used methodologies, from medical imaging to obtaining a functional physical model. The materials used to imitate specific organs and tissues, and the related technologies used to produce, them are included. The study covers publications in English, published by the end of 2022 and included in the Scopus. The obtained results emphasise the growing popularity of the issue, especially in the areas related to the attempt to imitate soft tissues with the use of low-cost 3D printing and plastic casting techniques.

Guide for starting or optimizing a 3D printing clinical service

Three-dimensional (3D) printing has applications in many fields and has gained substantial traction in medicine as a modality to transform two-dimensional scans into three-dimensional renderings. Patient-specific 3D printed models have direct patient care uses in surgical and procedural specialties, allowing for increased precision and accuracy in developing treatment plans and guiding surgeries. Medical applications include surgical planning, surgical guides, patient and trainee education, and implant fabrication. 3D printing workflow for a laboratory or clinical service that produces anatomic models and guides includes optimizing imaging acquisition and post-processing, segmenting the imaging, and printing the model. Quality assurance considerations include supervising medical imaging expert radiologists' guidance and self-implementing in-house quality control programs. The purpose of this review is to provide a workflow and guide for starting or optimizing laboratories and clinical services that 3D-print anatomic models or guides for clinical use.

Knowledge on Applications of 3D Design and Printing in Dentistry Among Dental Practitioners in Saudi Arabia: A Questionnaire-Based Survey

Background: This knowledge, attitude, and practices (KAP) survey will provide baseline data and identify gaps that may facilitate understanding and further action to plan, implement, and evaluate practice toward 3D-printing technology among dental practitioners in Saudi Arabia.

AIMS AND OBJECTIVES

The present study aims to assess dental practitioners' self-reported knowledge, attitude, and practice of 3D printing in Saudi Arabia.

METHODOLOGY

A cross-sectional, closed-ended questionnaire of registered dental practitioners in Saudi Arabia was conducted. A sample size of 156 was considered for analysis. After obtaining approval from the Institutional Review Board, Riyadh Elm University, the research was conducted during the month of April 2022 amongst 154 registered dental practitioners. The research was distributed among dental health specialists either working in dental colleges, dental clinics, or both in government as well as private settings. Dentists who were not actively involved in 3D printing were excluded. SPSS software, version 25.0, (IBM Corp., Armonk, NY) was used to analyze the data.

RESULTS AND CONCLUSION

Of all dentists included in the study, 98% were found to be aware that 3D printing in dentistry is used in Saudi Arabia and 2 % were not aware of its usage in Saudi Arabia. In total, 78.60% of the dentists felt that 3D-printed implant guides made the placement of implants the most accurate and least complicated procedure, and 21.40% of the dentists felt it was the least accurate and most complicated procedure.

CT-Derived 3D Printing for Coronary Artery Cannulation Simulator Design Manufacturing

Mastering coronary angiography requires practice. Cadavers and animals do not accurately represent the human anatomical body, and practicing with actual patients has medical safety issues. Simulation offers safe and realistic conditions for cardiology intervention training. In this study, we propose a novel 3D printed simulator that contains physically realistic anatomy and has four access points. It increases safety for patients and students, and production is low-cost. We aimed to make and validate this simulator design as a prototype for coronary cannulation training. It was designed using computed tomography (CT) scan data of aorta, coronary, and heart models, and was printed by 3D printing with resin materials consisting of 75% or 85% clear resin and 25% or 15% flexible resin additive. The simulator was constructed with a camera above the simulator with a degree of LAO of 30°/0°, a display table, and an acrylic box. Twelve validators were interviewed for their expert opinions and analyzed by a qualitative method. They scored the simulator’s suitability on a four-point Likert scale questionnaire. They described the simulator as having admirable values for all aspects (85.8%), curriculum suitability (92%), educational importance (94%), accuracy (83%), efficiency (78%), safety (87.5%), endurance (81.2%), aesthetics (80.7%), storage (85.4%), and affordability (85.8%).

Application of three-dimensional reconstruction of left upper lung lobes in anatomical segmental resection

BACKGROUND

The lobar and segmental anatomy are the basis for anatomical pulmonary segmentectomy.

METHODS

From October 2017 to June 2021, 136 patients with small pulmonary nodules scheduled for anatomical pulmonary segmentectomy at our institution underwent three-dimensional (3D) lung reconstruction. The anatomy of the left upper lobe (LUL) was statistically analyzed and graphically mapped using the reconstructed models, and the role of this reconstruction method in performing pulmonary segmentectomy was explored.

RESULTS

Through the analysis of the reconstructed models, the upper stem (S1 + 2 + 3) bronchus was classified as having two (94/136 cases) or three branches (42/136 cases). The upper stem artery had two branches in 24/136 patients, three in 60/136 cases, four in 44/136 cases, and five in 8/136 cases. A total of 103/136 upper stem veins had two branches, 26/136 had three branches, and 7/136 had four branches. The lingual stem (S4 + 5) bronchus was two-branched in 116/136 cases and three-branched in 20/136 cases, while the lingual artery was single-branched in 61/136 cases, two-branched in 70/136 cases, and three-branched in rare cases (5/136 cases). The lingual stem vein was unbranched in 119/136 cases and two-branched in 17/136 cases. Additionally, six unusual variants (<5%) were identified: one in the bronchus, with four cases; three in the pulmonary artery, with six cases; and two in the pulmonary vein, with two cases.

CONCLUSIONS

3D reconstruction can yield results similar to specimens for lung segment studies. The reconstruction strategy and the data presented in this article will be valuable references for thoracic surgeons performing anatomic resections.

Artificial intelligence assisted display in thoracic surgery: development and possibilities

In this golden age of rapid development of artificial intelligence (AI), researchers and surgeons realized that AI could contribute to healthcare in all aspects, especially in surgery. The popularity of low-dose computed tomography (LDCT) and the improvement of the video-assisted thoracoscopic surgery (VATS) not only bring opportunities for thoracic surgery but also bring challenges on the way forward. Preoperatively localizing lung nodules precisely, intraoperatively identifying anatomical structures accurately, and avoiding complications requires a visual display of individuals’ specific anatomy for surgical simulation and assistance. With the advance of AI-assisted display technologies, including 3D reconstruction/3D printing, virtual reality (VR), augmented reality (AR), and mixed reality (MR), computer tomography (CT) imaging in thoracic surgery has been fully utilized for transforming 2D images to 3D model, which facilitates surgical teaching, planning, and simulation. AI-assisted display based on surgical videos is a new surgical application, which is still in its infancy. Notably, it has potential applications in thoracic surgery education, surgical quality evaluation, intraoperative assistance, and postoperative analysis. In this review, we illustrated the current AI-assisted display applications based on CT in thoracic surgery; focused on the emerging AI applications in thoracic surgery based on surgical videos by reviewing its relevant researches in other surgical fields and anticipate its potential development in thoracic surgery.

Feasibility and accuracy of printed models of complex cardiac defects in small infants from cardiac computed tomography

BACKGROUND

Three-dimensional (3-D) printed models are increasingly used to enhance understanding of complex anatomy in congenital heart disease.

OBJECTIVE

To assess feasibility and accuracy of 3-D printed models obtained from cardiac CT scans in young children with complex congenital heart diseases.

MATERIALS AND METHODS

We included children with conotruncal heart anomalies who were younger than 2 years and had a cardiac CT scan in the course of their follow-up. We used cardiac CT scan datasets to generate 3-D models. To assess the models' accuracy, we compared four diameters for each child between the CT images and the printed models, including the largest diameters (D_max) of ventricular septal defects and aortic annulus and their minimal diameters (D_min).

RESULTS

We obtained images from 14 children with a mean age of 5.5 months (range 1-24 months) and a mean weight of 6.7 kg (range 3.4-14.5 kg). We generated 3-D models for all children. Mean measurement difference between CT images and 3-D models was 0.13 mm for D_min and 0.12 mm for D_max for ventricular septal defect diameters, and it was 0.16 mm for D_min and -0.13 mm for D_max for aortic annulus diameter, indicating a non-clinically significant difference.

CONCLUSION

Three-dimensional printed models could be feasibly generated from cardiac CT scans in a small pediatric population with complex congenital heart diseases. This technique is highly accurate and reliably reflects the same structural dimensions when compared to CT source images.

Preoperative non-invasive visual localization of synchronous multiple lung cancers using three-dimensional computed tomography lung reconstruction

BACKGROUND

Synchronous multiple primary lung cancers are becoming more common with increasing use of computed tomography for screening. Intraoperative localization and resection of ill-defined pulmonary ground-glass opacities during thoracoscopic resection is challenging. This study aimed to determine the clinical feasibility of non-invasive visual localization of these nodules by three-dimensional computed tomography lung reconstruction before sublobar resection.

METHODS

Forty-four patients with synchronous multiple primary lung cancers underwent thoracoscopic pulmonary resection at our institution between June 2017 and August 2019. Preadmission computed tomography images were downloaded and reconstructed into a three-dimensional model. Small nodules (< 15 mm) were localized non-invasively by three-dimensional computed tomography lung reconstruction before surgery. Patient demographics, nodule characteristics, procedural details, pathological data, and outcomes were obtained from the medical records.

RESULTS

One hundred and twenty-one pulmonary nodules from the 44 patients were scheduled for video-assisted thoracic surgery; 54 (44.6%) were pure ground-glass opacities and 57 (47.1%) were mixed ground-glass opacities. One hundred and seventeen nodules were localized preoperatively. The mean nodule diameter was 7.67 ± 3.87 mm. The mean distance from the nodule to the pleura was 14.84 ± 14.43 mm. All nodules were removed successfully by wedge resection (27 patients), lobectomy (26 patients), or segmentectomy (25 patients). Most lesions (85.1%) were malignant. Paraffin pathology revealed 12 cases of atypical adenomatous hyperplasia (9.92%), 13 of adenocarcinoma in situ (10.74%), 16 of minimally invasive adenocarcinoma (13.22%), and 73 of invasive adenocarcinoma (60.33%).

CONCLUSIONS

Three-dimensional computed tomography lung reconstruction is a feasible and alternative method of visual localization for small lung nodules before sublobar resection in some suitable patients.

Three-Dimensional Computed Tomography Bronchography and Angiography-Guided Thoracoscopic Segmentectomy for Pulmonary Nodules

BACKGROUND

Three-dimensional computed tomography bronchography and angiography (3D-CTBA) provides detailed imaging information for pulmonary segmentectomy. This study was performed to verify the feasibility of 3D-CTBA-guided thoracoscopic segmentectomy for the treatment of pulmonary nodules.

METHODS

A retrospective analysis was performed on all patients who underwent 3D-CTBA-guided uniport thoracoscopic segmentectomies or subsegmentectomies for pulmonary nodules in the period from May 2019 to May 2020. All of the information related to perioperative management and surgical operations was retrieved from the medical records and operating notes for detailed analysis.

RESULTS

A total of 104 eligible operations involving the resection of 110 nodules with diameters in the range of 5-20 mm were included. Under 3D-CTBA guidance, the pulmonary nodules were located with an accuracy of 100% (110/110) and the median resection margin was 24.3 mm (17-33 mm). Additionally, the segmental (subsegmental) bronchi, arteries, and veins were identified with accuracy rates of 100% (104/104), 96.2% (100/104), and 94.2% (98/104), respectively. The postoperative complications consisted of 3 cases of pulmonary infection (2.9%), 6 cases of arrhythmia (5.8%), 2 cases of hemoptysis (1.9%), 4 cases of air leak (3.8%), and 2 cases of subcutaneous emphysema (1.9%). No perioperative death occurred.

CONCLUSION

3D-CTBA-guided thoracoscopic segmentectomy is an effective surgical approach for the management of pulmonary nodules.

Computer assisted three-dimensional reconstruction of scene in firearm homicide

Worldwide advances in computer techniques are not yet recognised in the practice of forensic medicine. A promising application is their use in making a three-dimensional reconstruction of the crime scene. This study analyses this technique in a homicide by firearm. Queries regarding the direction and number of shots, position of the victim inside the car when shot at and presence of the accused at the crime scene were answered by a scientific model. Similar reconstruction of the scene, nailing the accused in a heinous crime, has not previously been reported as a study or a case. The paper anticipates impetus to the growth of literature in criminology and forensic sciences. It will also expedite the delivery of justice based on scientific evidence in controversial causes of death.

Establishing a point-of-care additive manufacturing workflow for clinical use

Additive manufacturing, or 3-Dimensional (3-D) Printing, is built with technology that utilizes layering techniques to build 3-D structures. Today, its use in medicine includes tissue and organ engineering, creation of prosthetics, the manufacturing of anatomical models for preoperative planning, education with high-fidelity simulations, and the production of surgical guides. Traditionally, these 3-D prints have been manufactured by commercial vendors. However, there are various limitations in the adaptability of these vendors to program-specific needs. Therefore, the implementation of a point-of-care in-house 3-D modeling and printing workflow that allows for customization of 3-D model production is desired. In this manuscript, we detail the process of additive manufacturing within the scope of medicine, focusing on the individual components to create a centralized in-house point-of-care manufacturing workflow. Finally, we highlight a myriad of clinical examples to demonstrate the impact that additive manufacturing brings to the field of medicine.

A Personalized 3D-Printed Model for Obtaining Informed Consent Process for Thyroid Surgery: A Randomized Clinical Study Using a Deep Learning Approach with Mesh-Type 3D Modeling

The aim of this study was to evaluate the usefulness of a personalized 3D-printed thyroid model that characterizes a patient's individual thyroid lesion. The randomized controlled prospective clinical trial (KCT0005069) was designed. Fifty-three of these patients undergoing thyroid surgery were randomly assigned to two groups: with or without a 3D-printed model of their thyroid lesion when obtaining informed consent. We used a U-Net-based deep learning architecture and a mesh-type 3D modeling technique to fabricate the personalized 3D model. The mean 3D printing time was 258.9 min, and the mean price for production was USD 4.23 for each patient. The size, location, and anatomical relationship of the tumor and thyroid gland could be effectively presented using the mesh-type 3D modeling technique. The group provided with personalized 3D-printed models showed significant improvement in all four categories (general knowledge, benefits and risks of surgery, and satisfaction; all p < 0.05). All patients received a personalized 3D model after surgery and found it helpful to understand the disease, operation, and possible complications and their overall satisfaction (all p < 0.05). In conclusion, the personalized 3D-printed thyroid model may be an effective tool for improving a patient's understanding and satisfaction during the informed consent process.

Affordable Three-Dimensional Printed Heart Models

This is a 7-years single institution study on low-cost cardiac three-dimensional (3D) printing based on the use of free open-source programs and affordable printers and materials. The process of 3D printing is based on several steps (image acquisition, segmentation, mesh optimization, slicing, and three-dimensional printing). The necessary technology and the processes to set up an affordable three-dimensional printing laboratory are hereby described in detail. Their impact on surgical and interventional planning, medical training, communication with patients and relatives, patients' perception on care, and new cardiac device development was analyzed. A total of 138 low-cost heart models were designed and printed from 2013 to 2020. All of them were from different congenital heart disease patients. The average time for segmentation and design of the hearts was 136 min; the average time for printing and cleaning the models was 13.5 h. The average production cost of the models was €85.7 per model. This is the most extensive series of 3D printed cardiac models published to date. In this study, the possibility of manufacturing three-dimensional printed heart models in a low-cost facility fulfilling the highest requirements from a technical and clinical point of view is demonstrated.

Application of 3D printing technology combined with PBL teaching model in teaching clinical nursing in congenital heart surgery: A case-control study

We aimed to explore the application of three-dimensional (3D) printing technology with problem-based learning (PBL) teaching model in clinical nursing education of congenital heart surgery, and to further improve the teaching quality of clinical nursing in congenital heart surgery. In this study, a total of 132 trainees of clinical nursing in congenital heart surgery from a grade-A tertiary hospital in 2019 were selected and randomly divided into 3D printing group or traditional group. The 3D printing group was taught with 3D printed heart models combined with PBL teaching technique, while the traditional group used conventional teaching aids combined with PBL technique for teaching. After the teaching process, the 2 groups of nursing students were assessed and surveyed separately to evaluate the results. Compared to the traditional group, the theoretical scores, clinical nursing thinking ability, self-evaluation for comprehensive ability, and teaching satisfaction from the questionnaires filled by the 3D printing group were all higher than the traditional group. The difference was found to be statistically significant (P < .05). Our study has shown the 3D printing technology combined with the PBL teaching technique in the clinical nursing teaching of congenital heart surgery achieved good results.

Advanced Multi-Dimensional Cellular Models as Emerging Reality to Reproduce In Vitro the Human Body Complexity

A hot topic in biomedical science is the implementation of more predictive in vitro models of human tissues to significantly improve the knowledge of physiological or pathological process, drugs discovery and screening. Bidimensional (2D) culture systems still represent good high-throughput options for basic research. Unfortunately, these systems are not able to recapitulate the in vivo three-dimensional (3D) environment of native tissues, resulting in a poor in vitro–in vivo translation. In addition, intra-species differences limited the use of animal data for predicting human responses, increasing in vivo preclinical failures and ethical concerns. Dealing with these challenges, in vitro 3D technological approaches were recently bioengineered as promising platforms able to closely capture the complexity of in vivo normal/pathological tissues. Potentially, such systems could resemble tissue-specific extracellular matrix (ECM), cell–cell and cell–ECM interactions and specific cell biological responses to mechanical and physical/chemical properties of the matrix. In this context, this review presents the state of the art of the most advanced progresses of the last years. A special attention to the emerging technologies for the development of human 3D disease-relevant and physiological models, varying from cell self-assembly (i.e., multicellular spheroids and organoids) to the use of biomaterials and microfluidic devices has been given.

Cardiac CT angiography: normal and pathological anatomical features-a narrative review

The normal and pathological anatomy of the heart and coronary arteries are nowadays widely developed topics and constitute a fundamental part of the cultural background of the radiologist. The introduction of cardiac ECG-gated synchronized CT scanners with an ever-increasing number of detectors and with increasingly high structural characteristics (increase in temporal resolution, increase in contrast resolution with dual-source, dual energy scanners) allows the virtual measurement of anatomical in vivo structures complying with heart rate with submillimetric precision permitting to clearly depict the normal anatomy and follow the pathologic temporal evolution. Accordingly to these considerations, cardiac computed tomography angiography (CCTA) asserts itself as a gold standard method for the anatomical evaluation of the heart and permits to evaluate, verify, measure and characterize structural pathological alterations of both congenital and acquired degenerative diseases. Accordingly, CCTA is increasingly used as a prognostic model capable of modifying the outcome of diseased patients in planning interventions and in the post-surgical/interventional follow-up. The profound knowledge of cardiac anatomy and function through highly detailed CCTA analysis is required to perform an efficient and optimal use in real-world clinical practice.

Augmented Reality and 3-Dimensional Printing Technologies for Guiding Complex Thoracoscopic Surgery

BACKGROUND

Virtual 3-dimentional models of the lungs have been used for guiding thoracoscopic procedures including segmentectomy and subsegmentectomy. However, the virtual models displayed on the screen were not tangible. A printed model with assistance of augmented reality (AR) might add value to guide surgical performance. We wanted to investigate whether the combined technology with patient-specific printed models and the AR display could offer better surgical outcomes than the on-screen models in complex thoracoscopic surgery.

METHODS

A total of 142 patients with early lung cancers undertaking thoracoscopic segmentectomy or subsegmentectomy. The 3-dimentional lung models were either displayed on screen (n = 87) or printed out and displayed using AR (n = 55) in the operating room. A propensity score-matching analysis was used to compare the surgical outcomes between the 2 groups.

RESULTS

The surgical outcomes data before and after propensity score matching showed 3-dimensional printing with AR had a shorter operating time (P = .001 and .001, respectively), less intraoperative blood loss (P = .024 and .006, respectively), and shorter length of hospital stay (P = .001 and .001, respectively) than the on-screen group. The complications and operating success rate (P = .846 and >.999, respectively) and (P = .567 and >.999, respectively) were not significantly different. Surgeons gave a higher score in the tangible group than in the on-screen group (P = .001 vs .001, respectively).

CONCLUSIONS

The printed 3-dimentional models enabled surgeons to see and touch interior structures of the lung. The AR provided instant guidance to the surgery in the operating room. The combination of these technologies produced positive values in guiding laparoscopic lung surgery.

Dynamic titanium prosthesis based on 3D-printed replica for chest wall resection and reconstruction

3D-printing technologies can assist the surgical planning and prosthesis engineering for the management of extended chest wall resection. Different types of prosthesis have been utilized over time, but some concerns remain about their impact on the respiratory function. Here we present a new kind of 3D-printed titanium prosthesis designed to be either strong and flexible. The prosthesis was created on a 1:1 3D-printed anatomic replica of the chest, used to delineate surgical margins and to define the reconstructive requirements.

Application of 3D modeling and printing technology in accurate resection of complicated thoracic tumors

Background

To explore the application value of three-dimensional (3D) reconstruction and 3D printing in preoperative evaluation of precise resection of complicated thoracic tumors.

Methods

A retrospective analysis of 34 patients with complicated thoracic tumors who were treated by radical surgery from March 2016 to June 2019 was made. According to whether 3D reconstruction and 3D printing was used, the patients were divided into research group and control group. In the control group, preoperative evaluation was performed according to CT image data, and the operation plan was drawn up; in the research group, preoperative simulation and preoperative operation plan design were carried out according to 3D reconstruction and 3D printing technology. The operation time, change of operation approach, intraoperative blood loss, hospitalization time and postoperative complications were compared between the two groups. We also retrospectively reviewed additional 12 cases of unresectable complicated thoracic tumors. The above 34 patients who were treated by radical surgery were set as the resectable group. Three-dimensional reconstruction was performed for all cases. The tumor size, location, smoothness of tumor-vascular contact surface, close contact with adjacent organs were compared between these two groups.

Results

The 3D reconstruction and 3D printing model were successfully established. The indexes of operation time, change of incision approach and blood loss in the research group were lower than those in the control group (P<0.05). All the patients were followed up for 6 months, and there was no death, no tumor recurrence and metastasis in the two groups. In the unresectable group, the score of position and smoothness of tumor-vascular contact surface were significantly higher than that in the resectable group.

Conclusions

3D reconstruction and 3D printing can effectively help surgeons carry out accurate surgical treatment, reduce the operation time and bleeding, reduce the risk of surgery, and facilitate the postoperative rehabilitation of patients, which has the value of promotion and application.

Printing a patient-specific instrument guide for skull osteoma management

BACKGROUND

To surgically remove osteoma and to keep an optimal cosmetic profile would be very challenging. To solve the difficulty, we utilized the three-dimensional (3D) printing technologies in generating a patient-specific instrument guide (PSIG) for the safe removal of a skull bone tumor.

METHODS

The preoperational brain computed tomography (CT) provided the digital imaging with thin slices, and then images were reconstructed into a 3D skull model. Based on the model, we designed a PSIG to make landmarks on the osteoma to avoid excessive removal of the skull bone. During the operation, the surgeons could remove the osteoma piece by piece by using the landmark as a reference point.

RESULTS

The PSIG was successfully applied to remove an osteoma that measured 60 × 48 × 40 mm over the left frontoparietal skull of a female patient. The 3D CT reconstruction taken both before and 4 months after surgery showed a significant change in the appearance of the osteoma.

CONCLUSION

The PSIG was able to guide the surgeon in the safe removal of the skull osteoma, as well as in maintaining the cosmetic skull profile.

Interventional Bronchoscopy

For over 150 years, bronchoscopy, especially flexible bronchoscopy, has been a mainstay for airway inspection, the diagnosis of airway lesions, therapeutic aspiration of airway secretions, and transbronchial biopsy to diagnose parenchymal lung disorders. Its utility for the diagnosis of peripheral pulmonary nodules and therapeutic treatments besides aspiration of airway secretions, however, has been limited. Challenges to the wider use of flexible bronchoscopy have included difficulty in navigating to the lung periphery, the avoidance of vasculature structures when performing diagnostic biopsies, and the ability to biopsy a lesion under direct visualization. The last 10-15 years have seen major advances in thoracic imaging, navigational platforms to direct the bronchoscopist to lung lesions, and the ability to visualize lesions during biopsy. Moreover, multiple new techniques have either become recently available or are currently being investigated to treat a broad range of airway and lung parenchymal diseases, such as asthma, emphysema, and chronic bronchitis, or to alleviate recurrent exacerbations. New bronchoscopic therapies are also being investigated to not only diagnose, but possibly treat, malignant peripheral lung nodules. As a result, flexible bronchoscopy is now able to provide a new and expanding armamentarium of diagnostic and therapeutic tools to treat patients with a variety of lung diseases. This State-of-the-Art review succinctly reviews these techniques and provides clinicians an organized approach to their role in the diagnosis and treatment of a range of lung diseases.

Three-Dimensional Printed Antimicrobial Objects of Polylactic Acid (PLA)-Silver Nanoparticle Nanocomposite Filaments Produced by an In-Situ Reduction Reactive Melt Mixing Process

In this study, an industrially scalable method is reported for the fabrication of polylactic acid (PLA)/silver nanoparticle (AgNP) nanocomposite filaments by an in-situ reduction reactive melt mixing method. The PLA/AgNP nanocomposite filaments have been produced initially reducing silver ions (Ag⁺) arising from silver nitrate (AgNO₃) precursor mixed in the polymer melt to elemental silver (Ag⁰) nanoparticles, utilizing polyethylene glycol (PEG) or polyvinyl pyrrolidone (PVP), respectively, as macromolecular blend compound reducing agents. PEG and PVP were added at various concentrations, to the PLA matrix. The PLA/AgNP filaments have been used to manufacture 3D printed antimicrobial (AM) parts by Fused Filament Fabrication (FFF). The 3D printed PLA/AgNP parts exhibited significant AM properties examined by the reduction in Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria viability (%) experiments at 30, 60, and 120 min duration of contact (p < 0.05; p-value (p): probability). It could be envisaged that the 3D printed parts manufactured and tested herein mimic nature’s mechanism against bacteria and in terms of antimicrobial properties, contact angle for their anti-adhesive behavior and mechanical properties could create new avenues for the next generation of low-cost and on-demand additive manufacturing produced personal protective equipment (PPE) as well as healthcare and nosocomial antimicrobial equipment.

COVID-19 and a novel initiative to improve safety by 3D printing personal protective equipment parts from computed tomography

BACKGROUND

Powered air-purifying respirators are in short supply and can break down with extended use. Replacement parts can become hard to acquire. The aim of this study was to create an innovative quality improvement proof of concept using rapid prototyping.

METHODS

Here we report three cases of 3D printed powered air-purifying respirator parts. 3D printing was performed on all parts using fused deposition modeling with standard polylactic acid, in the same way that presurgical models would be created. Measurements using an electronic caliper as well as CT scans were used to compare an original part to its corresponding 3D printed parts for accuracy.

RESULTS

Electronic caliper and computed tomography measurements both showed accuracy consistant with current published norms.

CONCLUSIONS

Ultimately, there will be questions surrounding intellectual property, effectiveness and potential long-term safety for these types of 3D printed parts. Future research should look into the addition of specific nanoparticles from the position of cost, efficacy, safety and improved accuracy.

Method to simulate distal flow resistance in coronary arteries in 3D printed patient specific coronary models

BACKGROUND

Three-dimensional printing (3DP) offers a unique opportunity to build flexible vascular patient-specific coronary models for device testing, treatment planning, and physiological simulations. By optimizing the 3DP design to replicate the geometrical and mechanical properties of healthy and diseased arteries, we may improve the relevance of using such models to simulate the hemodynamics of coronary disease. We developed a method to build 3DP patient specific coronary phantoms, which maintain a significant part of the coronary tree, while preserving geometrical accuracy of the atherosclerotic plaques and allows for an adjustable hydraulic resistance.

METHODS

Coronary computed tomography angiography (CCTA) data was used within Vitrea (Vital Images, Minnetonka, MN) cardiac analysis application for automatic segmentation of the aortic root, Left Anterior Descending (LAD), Left Circumflex (LCX), Right Coronary Artery (RCA), and calcifications. Stereolithographic (STL) files of the vasculature and calcium were imported into Autodesk Meshmixer for 3D model optimization. A base with three chambers was built and interfaced with the phantom to allow fluid collection and independent distal resistance adjustment of the RCA, LAD and LCX and branching arteries. For the 3DP we used Agilus for the arterial wall, VeroClear for the base and a Vero blend for the calcifications, respectively. Each chamber outlet allowed interface with catheters of varying lengths and diameters for simulation of hydraulic resistance of both normal and hyperemic coronary flow conditions. To demonstrate the manufacturing approach appropriateness, models were tested in flow experiments.

RESULTS

Models were used successfully in flow experiments to simulate normal and hyperemic flow conditions. The inherent mean resistance of the chamber for the LAD, LCX, and RCA, were 1671, 1820, and 591 (dynes ∙ sec/ cm5), respectively. This was negligible when compared with estimates in humans, with the chamber resistance equating to 0.65-5.86%, 1.23-6.86%, and 0.05-1.67% of the coronary resistance for the LAD, LCX, and RCA, respectively at varying flow rates and activity states. Therefore, the chamber served as a means to simulate the compliance of the distal coronary trees and to allow facile coupling with a set of known resistance catheters to simulate various physical activity levels.

CONCLUSIONS

We have developed a method to create complex 3D printed patient specific coronary models derived from CCTA, which allow adjustable distal capillary bed resistances. This manufacturing approach permits comprehensive coronary model development which may be used for physiologically relevant flow simulations.

Three-dimensional reconstruction/personalized three-dimensional printed model for thoracoscopic anatomical partial-lobectomy in stage I lung cancer: a retrospective study

Background

Considering the complexity of vascular or bronchial variations and the difficulty of nodule localization during segmental resection, the three-dimensional (3D) reconstruction and printing model can provide a guarantee for safe operation and, to some extent, can simplify the surgical procedure. We conducted this study to estimate the avail of 3D reconstruction and personalized model in anatomical partial-lobectomy (APL).

Methods

We prospectively collected and retrospectively reviewed the data of 298 cases who underwent APL in our institute from April 2017 to May 2019. The patients were divided into “3D-reconstruction” group (131 patients), “3D model” group (31 patients) and “non-3D” group (136 patients). We adopted the ANOVA analysis and Chi-square test to compare the perioperative data between the three groups. Subjective satisfaction questionnaires for surgeons were provided to evaluate the value of personalized 3D printed model.

Results

The proportion of complex segmentectomy in 3D model group (87.1%) was significantly higher than that in the 3D-reconstruction group (60.3%) and non-3D group (55.9%) (P=0.006), and the average operation time of complex segmentectomy in 3D model group (99.56 minutes) was significantly shorter than that of the other group (all P<0.05). The average intraoperative blood loss in the 3D model group (12.9 mL) was significantly lower than that in the 3D reconstruction group (20.9 mL) (P=0.001) and non-3D group (18.2 mL) (P=0.022). For simple segmentectomy, the operation time, postoperative drainage, and postoperative hospital stay were similar among the three groups. The questionnaire survey showed that most surgeons were satisfied with the clinical effectiveness of the personalized 3D printed model.

Conclusions

3D printing technology can improve understanding of the anatomy, decrease the operation time, and reduce the potential risk of thoracoscopic anatomical partial lobectomy in stage I lung cancer. A pre-operative rating scale was designed to standardize the application of this technology.

Effective approaches to three-dimensional digital reconstruction of fragmented human skeletal remains using laser surface scanning

The preservation and reconstruction of anthropological and archaeological remains has been given considerable attention in recent years, particularly within the fields of forensic science and palaeoanthropology. However, few studies have tapped the potential of using 3D technology to reconstruct, remodel and recontour remains and artefacts for the purpose of human identification. The aim of this study was to use 3D technology for the reconstruction and remodelling of fragmented and missing elements of skeletal remains. This project presents the application of three dimensional (3D) modalities to two different simulated forensic case scenarios where an attempt was made to remodel the missing element of the human cranium and reconstruction of fragmented replicated human mandible was performed. The accuracy of the reconstructed model was affirmed based on the anatomical features and digital analysis and methods for use in forensic practice are recommended.

3D printing tissue-mimicking materials for realistic transseptal puncture models

Applications of additive manufacturing (commonly referred to as 3D printing) in direct fabrication of models for pre-surgical planning, functional testing, and medical training are on the rise. However, one current limitation to the accuracy of models for cardiovascular procedural training is a lack of printable materials that accurately mimic human tissue. Most of the available elastomeric materials lack mechanical properties representative of human tissues. To address the gap, the authors explore the multi-material capability of material jetting additive manufacturing to combine non-curing and photo-curing inks to achieve material properties that more closely replicate human tissues. The authors explore the impact of relative material concentration on tissue-relevant properties from puncture and tensile testing under submerged conditions. Further, the authors demonstrate the ability to mimic the mechanical properties of the fossa ovalis, which proves beneficial for accurately simulating transseptal punctures. A fossa ovalis mimic was printed and assembled within a full patient-specific heart model for validation, where it exhibited accuracy in both mechanical properties and geometry. The explored material combination provides the opportunity to fabricate future medical models that are more realistic and better suited for pre-surgical planning and medical student training. This will ultimately guide safer, more efficient practices.

Three-Dimensional Printing of Prenatal Ultrasonographic Diagnosis of Cleft Lip and Palate: Presenting the Needed "Know-How" and Discussing Its Use in Parental Education

Parental prenatal counseling is of paramount significance since parents often experience an emotional crisis with feelings of disappointment and helplessness. Three-dimensional (3D) printed model of the unborn child's face presenting with cleft lip and palate, based on ultrasonographic information, could be used to provide visual 3D information, further enhancing the prospective parent's comprehension of their unborn child's pathology and morphology, helping them to be psychologically prepared and improving the communication with the caretaking team. Prospective parents appreciate if prenatal counseling is available with the most detailed information as well as additional resources. The technique necessary to create 3D models after ultrasonographic information is explained, and the related costs are evaluated. The use of such models in parental education is then discussed.

Three-Dimensional Printed Polylactic Acid (PLA) Surgical Retractors with Sonochemically Immobilized Silver Nanoparticles: The Next Generation of Low-Cost Antimicrobial Surgery Equipment

A versatile method is reported for the manufacturing of antimicrobial (AM) surgery equipment utilising fused deposition modelling (FDM), three-dimensional (3D) printing and sonochemistry thin-film deposition technology. A surgical retractor was replicated from a commercial polylactic acid (PLA) thermoplastic filament, while a thin layer of silver (Ag) nanoparticles (NPs) was developed via a simple and scalable sonochemical deposition method. The PLA retractor covered with Ag NPs (PLA@Ag) exhibited vigorous AM properties examined by a reduction in Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli) bacteria viability (%) experiments at 30, 60 and 120 min duration of contact (p < 0.05). Scanning electron microscopy (SEM) showed the surface morphology of bare PLA and PLA@Ag retractor, revealing a homogeneous and full surface coverage of Ag NPs. X-Ray diffraction (XRD) analysis indicated the crystallinity of Ag nanocoating. Ultraviolent-visible (UV-vis) spectroscopy and transmission electron microscopy (TEM) highlighted the AgNP plasmonic optical responses and average particle size of 31.08 ± 6.68 nm. TEM images of the PLA@Ag crossection demonstrated the thickness of the deposited Ag nanolayer, as well as an observed tendency of AgNPs to penetrate though the outer surface of PLA. The combination of 3D printing and sonochemistry technology could open new avenues in the manufacturing of low-cost and on-demand antimicrobial surgery equipment.

Digital reconstruction of fragmented tooth remains in forensic context

Forensic odontology majorly focuses on the identification of victims through the analyses of oral and para–oral structures. Exposure to high temperatures and trauma can occur in mass disasters and may lead to the fracturing and fragmentation of teeth. These fragments may become very fragile and easily damaged while handling. Conventional methodologies such as the use of transparent nail polish, hair spray, cyanoacrylate or adhesives have been used to stabilize the fragmented pieces. This study introduces a new and innovative digital technique that utilizes three-dimensional surface scanning (3DSS) and rapid prototyping techniques to reconstruct fractured portions of the teeth. The results of qualitative congruency analysis suggest that over all variance of morphological error (0.0526 ± 0.05) mm. These results imply that the reconstructed 3D model can be used for various morphometric analyses.

Cinematic rendering for three-dimensional reconstructions of the chest wall: a new reality

Computed tomography with multiple detectors and the advancement of processors improved rendered images and three-dimensional reconstructions in clinical practice. Traditional axial slices form non-intuitive images because they are seen in only one plane. The three-dimensional reconstructions can show structures details and diseases with complex anatomy in different perspectives. Cinematic rendering is a newly three-dimensional reconstruction technique, already approved for clinical use, which can produce realistic images from traditional computed tomography data. The algorithm used is based on light trajectory methods and the global lighting model, which simulate thousands of images from all possible directions. Thus, the technique shapes the physical propagation of light and generates a realistic three-dimensional image with depth, shadows and more anatomic details. It is a multidimensional rendering acquired through complex lighting effects. The aim of this article was to show the advance of three-dimensional technology with the cinematic rendering in images exams of the thoracic wall.

Simulation-based surgical education in cardiothoracic training

Simulation has emerged as a feasible adjunct to surgical education and training for most specialties. It provides trainees with an immersive, realistic way to learn a variety of skills in a safe environment with the end goal of improving patient safety. There are three broad types of simulators: full mannequin simulators, part-task trainers or bench models and virtual reality systems. This review aims to describe the current use of simulation in cardiothoracic surgical education and training. We identified multiple procedures that can be simulated in cardiothoracic surgery using a combination of the above simulators, three-dimensional printing and computer-based simulation. All studies that assessed the efficacy of simulators showed that simulation enhances learning and trainee performance allowing for repetitive training until the acquisition of competence but further research into how it translates into the operating theatre is required. In Australia, cardiac surgery simulation is not yet part of the training curricula, but simulators are available for certain tasks and procedures.

Feasibility of Device Closure for Multiple Atrial Septal Defects With an Inferior Sinus Venosus Defect: Procedural Planning Using Three-Dimensional Printed Models

BACKGROUND

Multiple atrial septal defects (ASD) with an inferior sinus venosus defect (SVD) have always been considered to be contraindications for interventional therapy. On the basis of early experience using a patent ductus arteriosus (PDA) occluder for interventional treatment for inferior ASD, this study investigated the feasibility of transcatheter closure of multiple ASDs with an inferior SVD under the guidance of three-dimensional (3D) printed heart models.

METHODS

Between August 2016 and February 2017, five patients who were diagnosed with multiple ASDs with an inferior SVD at the First Affiliated Hospital of Xi'an Jiaotong University underwent cardiac computed tomography (CT) scans and three-dimensional (3D) echocardiography to generate heart disease models by a 3D printing technique. The best occlusion program was determined through a simulated closure on the model. Percutaneous device closure of multiple ASDs with an inferior SVD was performed following the predetermined program, guided only by fluoroscopy. Follow-up included electrocardiography, transthoracic echocardiography, and transoesophageal echocardiography.

RESULTS

Three-dimensional (3D) printed models for all five patients were produced successfully. Four (4) patients had a secundum ASD with an inferior sinus venosus ASD, and one patient had a patent foramen ovale (PFO) with an inferior sinus venosus ASD. All patients were successfully treated with interventional therapy. Inferior sinus venosus ASD was percutaneously closed using the PDA occluder, and the additional secundum ASD or PFO in each patient was percutaneously closed using an ASD or PFO occluder at the same time. There was no device embolisation, procedure-related death or pericardial tamponade. During the 1-year follow-up, a minor residual shunt was detected in one patient.

CONCLUSION

The use of 3D printed ASD models provides a useful reference for transcatheter device closure of multiple ASD with an inferior SVD. This approach can provide a new treatment strategy for inferior sinus venosus ASD, which has been considered a contraindication for interventional therapy. However, long-term follow-up in a large number of patients is still warranted.

Hybrid nanocomposite as a chest wall graft with improved integration by adipose-derived stem cells

Surgery of the chest wall is potentially required to cover large defects after  removal of malignant tumours. Usually, inert and non-degradable Gore-Tex serves to replace the missing tissue. However, novel biodegradable materials combined with stem cells are available that stimulate the healing. Based on poly-lactic-co-glycolic acid and amorphous calcium phosphate nanoparticles (PLGA/aCaP) and pure PLGA, a dual layer biodegradable hybrid nanocomposite was generated. Mouse adipose-derived stem cells were cultered on electrospun disks (ASCs of C57BL/6), and biomechanical tests were performed. The cell-seeded scaffolds were engrafted in C57BL/LY5.1 mice to serve as a chest wall substitute. Cell invasion into the bi-layered material, extent of CD45⁺ cells, inflammatory response, neo-vascularization and ECM composition were determined at 1 and 2 months post-surgery, respectively. The bi-layered hybrid nanocomposite was stable after a 2-week in vitro culture, in contrast to PLGA/aCaP without a PLGA layer. There was a complete biointegration and good vascularization in vivo. The presence of ASCs attracted more CD45⁺ cells (hematopoietic origin) compared to cell-free scaffolds. Inflammatory reaction was similar for both groups (±ASCs) at 8 weeks. A bi-layered hybrid nanocomposite fabricated of electrospun PLGA/aCaP and a reinforcing layer of pristine PLGA is an ideal scaffold for chest wall reconstruction. It is stable and allows a proper host tissue integration. If ASCs are seeded, they attract more CD45⁺ cells, supporting the regeneration process.

Role of innovative 3D printing models in the management of hepatobiliary malignancies

Three-dimensional (3D) printing has recently emerged as a new technique in various liver-related surgical fields. There are currently only a few systematic reviews that summarize the evidence of its impact. In order to construct a systematic literature review of the applications and effects of 3D printing in liver surgery, we searched the PubMed, Embase and ScienceDirect databases for relevant titles, according to the PRISMA statement guidelines. We retrieved 162 titles, of which 32 met the inclusion criteria and are reported. The leading application of 3D printing in liver surgery is for preoperative planning. 3D printing techniques seem to be beneficial for preoperative planning and educational tools, despite their cost and time requirements, but this conclusion must be confirmed by additional randomized controlled trials.