Review of the effect of 3D medical printing and virtual reality on urology training with ‘MedTRain3DModsim’ Erasmus + European Union Project

Three-Dimensional Printing and Bioprinting in Renal Transplantation and Regenerative Medicine: Current Perspectives

For patients with end-stage kidney disease (ESKD), renal transplantation is the treatment of choice, constituting the most common solid organ transplantation. This study aims to provide a comprehensive review regarding the application of three-dimensional (3D) printing and bioprinting in renal transplantation and regenerative medicine. Specifically, we present studies where 3D-printed models were used in the training of surgeons through renal transplantation simulations, in patient education where patients acquire a higher understanding of their disease and the proposed operation, in the preoperative planning to facilitate decision-making, and in fabricating customized, tools and devices. Three-dimensional-printed models could transform how surgeons train by providing surgical rehearsal platforms across all surgical specialties, enabling training with tissue realism and anatomic precision. The use of 3D-printed models in renal transplantations has shown a positive impact on surgical outcomes, including the duration of the operation and the intraoperative blood loss. Regarding 3D bioprinting, the technique has shown promising results, especially in the field of microfluidic devices, with the development of tissue demonstrating proximal tubules, glomerulus, and tubuloinerstitium function, and in renal organoid development. Such models can be applied for renal disease modeling, drug development, and renal regenerative medicine.

Anatomic Depth Estimation and 3-Dimensional Reconstruction of Microsurgical Anatomy Using Monoscopic High-Definition Photogrammetry and Machine Learning

BACKGROUND

Immersive anatomic environments offer an alternative when anatomic laboratory access is limited, but current three-dimensional (3D) renderings are not able to simulate the anatomic detail and surgical perspectives needed for microsurgical education.

OBJECTIVE

To perform a proof-of-concept study of a novel photogrammetry 3D reconstruction technique, converting high-definition (monoscopic) microsurgical images into a navigable, interactive, immersive anatomy simulation.

METHODS

Images were acquired from cadaveric dissections and from an open-access comprehensive online microsurgical anatomic image database. A pretrained neural network capable of depth estimation from a single image was used to create depth maps (pixelated images containing distance information that could be used for spatial reprojection and 3D rendering). Virtual reality (VR) experience was assessed using a VR headset, and augmented reality was assessed using a quick response code-based application and a tablet camera.

RESULTS

Significant correlation was found between processed image depth estimations and neuronavigation-defined coordinates at different levels of magnification. Immersive anatomic models were created from dissection images captured in the authors' laboratory and from images retrieved from the Rhoton Collection. Interactive visualization and magnification allowed multiple perspectives for an enhanced experience in VR. The quick response code offered a convenient method for importing anatomic models into the real world for rehearsal and for comparing other anatomic preparations side by side.

CONCLUSION

This proof-of-concept study validated the use of machine learning to render 3D reconstructions from 2-dimensional microsurgical images through depth estimation. This spatial information can be used to develop convenient, realistic, and immersive anatomy image models.

Innovative training modality for sacral neuromodulation (SNM): Patient-specific computerized tomography (CT) reconstructed 3D-printed training system: ICS School of Modern Technology novel training modality

INTRODUCTION

Sacral neuromodulation (SNM) is an effective treatment of urinary and bowel dysfunction, including secondary to neurological disorders. The learning curve for the optimal electrode placement for SNM is steep, expensive, and limited by patient factors such as obesity and previous injuries. We aim to create a patient specific 3-dimensional (3D) model for successful SNM training.

MATERIALS AND METHODS

A total of 26 urology residents who had different level of knowledge and experience were enrolled to the 3D SNM training program. The creation of 3D sacrum model has been started with evaluation of real patient computerized tomography images and creation of Digital Imaging and Communications in Medicine files. The segmented anatomic structures from the files then edited and stereolithographic files were generated for 3D-model prints via Mimics^© software. The 3D-printed models were used for training and evaluation of participants during the SNM intervention was performed. The evaluation of 3D SNM model training was led by one mentor who is expert on SNM.

RESULTS

On the preprinted 3D sacrum model all 26 participants were requested to perform the essential steps to complete a SNM procedure and individual procedure time was recorded. The mean and median scores were 18.8 and 19, respectively according to Likert scores (min 11 max 28).

CONCLUSIONS

SNM is increasing in popularity as a treatment option with physicians and patients with refractory symptoms. Few experienced specialists exist, and more effective training methods are needed to tackle the increasing demand, and individual patient anatomy.

Simulation-based prostate enucleation training: Initial experience using 3D-printed organ phantoms

INTRODUCTION

Anatomical endoscopic enucleation of the prostate (AEEP) is an effective treatment for benign prostatic hyperplasia (BPH); however, there is controversy regarding the difficulty of learning such a technique. Simulation-based training can mimic real-life surgeries and help surgeons develop skills they can transfer to the operating room, thereby improving patient safety. This study aimed to evaluate the validity of a novel organ phantom for use in AEEP simulation training.

METHODS

Participants performed AEEP on organ phantom simulators during a Masterclass using one of three energy modalities: holmium:YAG laser, thulium fiber laser, or bipolar energy. The organ phantom is composed of hydrogels and uses 3D molds to recreate prostatic tissue. Participants completed a questionnaire assessing content validity, face validity, feasibility, and acceptability of using the prostate organ phantom.

RESULTS

The novice group consisted of 13 urologists. The median number of AEEP previously performed was 0 (interquartile range [IQR] 0-2). Two experts in AEEP (surgeons having performed over 100 AEEP interventions) also participated. All participants agreed or strongly agreed that there is a role for simulators in AEEP training. Participants positively rated the overall operative experience (7.3/10). Morcellation (4.7/10) and hemostasis (3.1/10) were deemed the least realistic steps. All participants considered it feasible to incorporate this organ phantom into training programs and 92.9% agreed that it teaches skills transferrable to the operating room.

CONCLUSIONS

This study has established content and face validity for AEEP with three different energy sources for an organ phantom. Participants considered its use both feasible and appropriate for AEEP training purposes.

Development and Validation of a Novel Methodological Pipeline to Integrate Neuroimaging and Photogrammetry for Immersive 3D Cadaveric Neurosurgical Simulation

Background

Visualizing and comprehending 3-dimensional (3D) neuroanatomy is challenging. Cadaver dissection is limited by low availability, high cost, and the need for specialized facilities. New technologies, including 3D rendering of neuroimaging, 3D pictures, and 3D videos, are filling this gap and facilitating learning, but they also have limitations. This proof-of-concept study explored the feasibility of combining the spatial accuracy of 3D reconstructed neuroimaging data with realistic texture and fine anatomical details from 3D photogrammetry to create high-fidelity cadaveric neurosurgical simulations.

Methods

Four fixed and injected cadaver heads underwent neuroimaging. To create 3D virtual models, surfaces were rendered using magnetic resonance imaging (MRI) and computed tomography (CT) scans, and segmented anatomical structures were created. A stepwise pterional craniotomy procedure was performed with synchronous neuronavigation and photogrammetry data collection. All points acquired in 3D navigational space were imported and registered in a 3D virtual model space. A novel machine learning-assisted monocular-depth estimation tool was used to create 3D reconstructions of 2-dimensional (2D) photographs. Depth maps were converted into 3D mesh geometry, which was merged with the 3D virtual model’s brain surface anatomy to test its accuracy. Quantitative measurements were used to validate the spatial accuracy of 3D reconstructions of different techniques.

Results

Successful multilayered 3D virtual models were created using volumetric neuroimaging data. The monocular-depth estimation technique created qualitatively accurate 3D representations of photographs. When 2 models were merged, 63% of surface maps were perfectly matched (mean [SD] deviation 0.7 ± 1.9 mm; range −7 to 7 mm). Maximal distortions were observed at the epicenter and toward the edges of the imaged surfaces. Virtual 3D models provided accurate virtual measurements (margin of error <1.5 mm) as validated by cross-measurements performed in a real-world setting.

Conclusion

The novel technique of co-registering neuroimaging and photogrammetry-based 3D models can (1) substantially supplement anatomical knowledge by adding detail and texture to 3D virtual models, (2) meaningfully improve the spatial accuracy of 3D photogrammetry, (3) allow for accurate quantitative measurements without the need for actual dissection, (4) digitalize the complete surface anatomy of a cadaver, and (5) be used in realistic surgical simulations to improve neurosurgical education.

Technological resources for teaching and learning about human anatomy in the medical course: Systematic review of literature

The consolidation of technology as an alternative strategy to cadaveric dissection for teaching anatomy in medical courses was accelerated by the recent Covid-19 pandemic, which caused the need for social distance policies and the closure of laboratories and classrooms. Consequently, new technologies were created, and those already been developed started to be better explored. However, information about many of these instruments and resources is not available to anatomy teachers. This systematic review presents the technological means for teaching and learning about human anatomy developed and applied in medical courses in the last ten years, besides the infrastructure necessary to use them. Studies in English, Portuguese, and Spanish were searched in MEDLINE, Scopus, ERIC, LILACS, and SciELO databases, initially resulting in a total of 875 identified articles, from which 102 were included in the analysis. They were classified according to the type of technology used: three-dimensional (3D) printing (n = 22), extended reality (n = 49), digital tools (n = 23), and other technological resources (n = 8). It was made a detailed description of technologies, including the stage of the medical curriculum in which it was applied, the infrastructure utilized, and which contents were covered. The analysis shows that between all technologies, those related to the internet and 3D printing are the most applicable, both in student learning and the financial cost necessary for its structural implementation.

Clinical Value of Patient-Specific Three-Dimensional Printing of Kidney Before Partial Nephrectomy: A Qualitative Assessment

Objectives: To qualitatively assess the clinical usefulness of patient-specific high-fidelity three-dimensional (3D) print model of kidney before partial nephrectomy (PN) and to identify subset domains where it may help in clinical terms. Materials and Methods: Thirteen 3D models were printed for tumors having RENAL nephrometry score of ≥8. Their usage for PN was assessed prospectively using a qualitative questionnaire to be answered on a Likert scale of 1-10. The questions focused on realistic resemblance, preoperative dry surgical run, intertest comparison, surgical impact, and overall beneficence domains as perceived by primary surgeons with respect to surgical conduct during PN. Results: Mean RENAL score was 9.15 (8-11). Models were rated high (9.07 ± 0.86) for realistic resemblance domain and were rated better than contrast-enhanced computed tomography (CECT) (8.38 ± 0.87) and intraoperative ultrasonography (8.07 ± 1.26) for orientation regarding resection margins. A further marginal improvement to 8.2 ± 0.84 was noted against ultrasound where surgeon did a dry cut preoperatively. Use of superselective arterial approach in four, precise awareness about dissection of a major vessel in four, retroperitoneoscopic approach in one, and surgical margin awareness in three were directly attributed to the model. Overall utility of having a model printed was rated high (8.23 ± 1.3). Conclusion: The 3D print models of complex renal tumors have high realistic resemblance to actual patient's anatomy. They were rated better than preoperative CECT or intraoperative ultrasonography for orientation regarding surgical resection margins. It may also help change or modify the surgical plan in a subset of patients with a potential to improve overall outcomes in these complex cases.

The Role of 3D-Printed Phantoms and Devices for Organ-specified Appliances in Urology

Urology is one of the fields that are always at the frontline of bringing scientific advancements into clinical practice, including 3D printing (3DP). This study aims to discuss and presents the current role of 3D-printed phantoms and devices for organ-specified applications in urology. The discussion started with a literature search regarding the two mentioned topics within PubMed, Embase, Scopus, and EBSCOhost databases. 3D-printed urological organ phantoms are reported for providing residents new insight regarding anatomical characteristics of organs, either normal or diseased, in a tangible manner. Furthermore, 3D-printed organ phantoms also helped urologists to prepare a pre-surgical planning strategy with detailed anatomical models of the diseased organs. In some centers, 3DP technology also contributed to developing specified devices for disease management. To date, urologists have been benefitted by 3D-printed phantoms and devices in the education and disease management of organs of in the genitourinary system, including kidney, bladder, prostate, ureter, urethra, penis, and adrenal. It is safe to say that 3DP technology can bring remarkable changes to daily urological practices.