Percutaneous Kidney Puncture with Three-dimensional Mixed-reality Hologram Guidance: From Preoperative Planning to Intraoperative Navigation

Visual extended reality tools in image-guided surgery in urology: a systematic review

PURPOSE

The aim of this systematic review is to assess the clinical implications of employing various Extended Reality (XR) tools for image guidance in urological surgery.

METHODS

In June 2023, a systematic electronic literature search was conducted using the Medline database (via PubMed), Embase (via Ovid), Scopus, and Web of Science. The search strategy was designed based on the PICO (Patients, Intervention, Comparison, Outcome) criteria. Study protocol was registered on PROSPERO (registry number CRD42023449025). We incorporated retrospective and prospective comparative studies, along with single-arm studies, which provided information on the use of XR, Mixed Reality (MR), Augmented Reality (AR), and Virtual Reality (VR) in urological surgical procedures. Studies that were not written in English, non-original investigations, and those involving experimental research on animals or cadavers were excluded from our analysis. The quality assessment of comparative and cohort studies was conducted utilizing the Newcastle-Ottawa scale, whilst for randomized controlled trials (RCTs), the Jadad scale was adopted. The level of evidence for each study was determined based on the guidelines provided by the Oxford Centre for Evidence-Based Medicine.

RESULTS

The initial electronic search yielded 1,803 papers after removing duplicates. Among these, 58 publications underwent a comprehensive review, leading to the inclusion of 40 studies that met the specified criteria for analysis. 11, 20 and 9 studies tested XR on prostate cancer, kidney cancer and miscellaneous, including bladder cancer and lithiasis surgeries, respectively. Focusing on the different technologies 20, 15 and 5 explored the potential of VR, AR and MR. The majority of the included studies (i.e., 22) were prospective non-randomized, whilst 7 and 11 were RCT and retrospective studies respectively. The included studies that revealed how these new tools can be useful both in preoperative and intraoperative setting for a tailored surgical approach.

CONCLUSIONS

AR, VR and MR techniques have emerged as highly effective new tools for image-guided surgery, especially for urologic oncology. Nevertheless, the complete clinical advantages of these innovations are still in the process of evaluation.

Comparing Different Registration and Visualization Methods for Navigated Common Femoral Arterial Access-A Phantom Model Study Using Mixed Reality

Mixed reality (MxR) enables the projection of virtual three-dimensional objects into the user's field of view via a head-mounted display (HMD). This phantom model study investigated three different workflows for navigated common femoral arterial (CFA) access and compared it to a conventional sonography-guided technique as a control. A total of 160 punctures were performed by 10 operators (5 experts and 5 non-experts). A successful CFA puncture was defined as puncture at the mid-level of the femoral head with the needle tip at the central lumen line in a 0° coronary insertion angle and a 45° sagittal insertion angle. Positional errors were quantified using cone-beam computed tomography following each attempt. Mixed effect modeling revealed that the distance from the needle entry site to the mid-level of the femoral head is significantly shorter for navigated techniques than for the control group. This highlights that three-dimensional visualization could increase the safety of CFA access. However, the navigated workflows are infrastructurally complex with limited usability and are associated with relevant cost. While navigated techniques appear as a potentially beneficial adjunct for safe CFA access, future developments should aim to reduce workflow complexity, avoid optical tracking systems, and offer more pragmatic methods of registration and instrument tracking.

Navigation systems and 3D imaging in percutaneous nephrolithotripsy: improving outcomes and safety

PURPOSE OF REVIEW

Percutaneous nephrolithotripsy (PCNL) is the first-line management option for large kidney stones (>2 cm). It remains, however, a demanding procedure with considerable morbidity. The present narrative review summarizes recent knowledge from original research studies investigating navigation systems/three-dimensional (3D) imaging in PCNL, particularly on publications during the past 12-18 months.

RECENT FINDINGS

Navigation systems and 3D imaging are primarily used for preoperative planning, with few intra-operative applications. Patient management and residents' training could benefit from their use.

SUMMARY

Navigation systems and 3D imaging technology have emerged as a potential game-changer in PCNL. Even though available evidence is currently scarce/inconclusive, the safety/efficacy of navigation systems and 3D dimensional imaging use in PCNL appears promising. This advanced technology offers precise anatomical mapping, improved visualization, and surgical accuracy. Enabling a comprehensive preoperative evaluation and improving guidance, navigation systems, and 3D imaging technology may improve the safety and efficacy of PCNL. With continuous technological evolution, it is expected that improvements/innovations will offer further aid in such demanding procedures. Familiarization and cost reduction are necessary for widespread application, while larger-scale prospective studies and well designed randomized controlled trials are still needed.

Potential Applications of New Headsets for Virtual and Augmented Reality in Urology

Virtual and augmented reality (VR/AR) technologies hold great promise in various medical fields. The release of a new generation of headsets for medical enhanced VR/AR (MER) opens new possibilities for applications in medicine, particularly in urology, to improve accessibility to everyone. These innovative headsets offer deep immersion without requiring a controller, which represents a novel approach to VR/AR engagement. The potential of these headsets applies to all aspects of urology, including surgical training, virtual meetings, communication between health care providers, patient counseling, telemedicine, delivering patient advice, and pain control. MER has the potential to improve operative planning and enhance intraoperative navigation and spatial awareness. The surgeon's visualization and overall experience can be significantly enhanced via improved guidance and visualization, ultimately leading to greater precision and safety. This cutting-edge technology has the potential to reshape urology practice, communication methods, and medical procedures, and ultimately to improve patients' experience of their urological condition. PATIENT SUMMARY: This mini review explores how a new generation of headsets for medical enhanced virtual reality could revolutionize urology by improving surgical planning, assistance during procedures, and medical education. Patients can benefit from better pain management and a deeper understanding of their conditions. However, challenges such as costs, accuracy, and ethical concerns must be addressed. This technology holds promise for transforming urological practice and patient care.

A new training model using the self-healing properties of supramolecular hydrogels for endoscopic combined intrarenal surgery

The combination of hydronephrosis formation, ureteroscopic imaging, and ultrasound delineation has not been included in any non-biological training model of percutaneous nephrolithotomy or endoscopic combined intrarenal surgery. We aimed to develop a realistic kidney phantom using the self-healing properties of supramolecular hydrogels for percutaneous nephrolithotomy and endoscopic combined intrarenal surgery and evaluate its suitability as a training model.Expert and resident urologists performed ultrasound-guided renal pelvic punctures and flexible ureteroscopies for endoscopic combined intrarenal surgery using a training model. Subsequently, the training model was evaluated using a 17-item Likert scale questionnaire (range, 1-5 points). After being filled with carrageenan, the collecting system was inflated, and the relationship between the collecting system volume and collecting system pressure was determined. The durability of the model was verified by repeatedly inserting a 16-Fr access sheath. Five novices and seven urology experts performed the procedure. The mean questionnaire score was 4.25 (standard deviation, 0.37). The model was able to hold 50 mL of air, and the pressure in the collecting system ranged from 6 to 33 mmHg. Repeated punctures were possible even when a 16-Fr access sheath was inserted. Our new training model included the self-healing properties of supramolecular hydrogels, which are tough and flexible and can be evaluated using ultrasonography. According to the questionnaire score, the model was highly satisfactory and has potential as a new educational tool.

Application of image overlapping in percutaneous nephrolithotomy

OBJECTIVE

To investigate the application of ultrasound and CT image overlap in percutaneous nephrolithotomy (PCNL).

METHODS

A total of 140 patients with complicated kidney stones requiring PCNL were prospectively enrolled, from January 2020 to December 2022. These patients were randomly divided into 2 groups, with 70 patients each in the research group and the control group. All participants underwent dual-source, non-contrast CT scan of both kidneys and pelvis before surgery. Preoperative three-dimensional CT reconstruction and simulated puncture were performed in patients from the research group. The best puncture path was determined through ultrasound and CT image overlap. Puncture guided by regular CT and ultrasound was conducted in patients from the control group. Differences in the surgical outcomes between the two groups were compared.

RESULTS

Compared to the control group, the research group had higher stone clearance rate in stage I PCNL, success rate of one-time puncture, less percutaneous channels, less reduction of hemoglobin and shorter procedure time. Complications in stage I PCNL were comparable in the two groups, and there was no significant change in the final stone clearance rates between the two groups.

CONCLUSION

An optimal puncture channel can be chosen using ultrasound and CT image overlap. PCNL can be achieved with precise puncturing, thus achieving coincidence between imaging and anatomy and reducing the amount of blood loss during stage I of PCNL. It also shortens the procedure time and improves stone clearance rate of PCNL.

Application of Mixed Reality to Ultrasound-guided Femoral Arterial Cannulation During Real-time Practice in Cardiac Interventions

Mixed reality opens interesting possibilities as it allows physicians to interact with both, the real physical and the virtual computer-generated environment and objects, in a powerful way. A mixed reality system, based in the HoloLens 2 glasses, has been developed to assist cardiologists in a quite complex interventional procedure: the ultrasound-guided femoral arterial cannulations, during real-time practice in interventional cardiology. The system is divided into two modules, the transmitter module, responsible for sending medical images to HoloLens 2 glasses, and the receiver module, hosted in the HoloLens 2, which renders those medical images, allowing the practitioner to watch and manage them in a 3D environment. The system has been successfully used, between November 2021 and August 2022, in up to 9 interventions by 2 different practitioners, in a large public hospital in central Spain. The practitioners using the system confirmed it as easy to use, reliable, real-time, reachable, and cost-effective, allowing a reduction of operating times, a better control of typical errors associated to the interventional procedure, and opening the possibility to use the medical imagery produced in ubiquitous e-learning. These strengths and opportunities were only nuanced by the risk of potential medical complications emerging from system malfunction or operator errors when using the system (e.g., unexpected momentary lag). In summary, the proposed system can be taken as a realistic proof of concept of how mixed reality technologies can support practitioners when performing interventional and surgical procedures during real-time daily practice.

3D Model Artificial Intelligence-Guided Automatic Augmented Reality Images during Robotic Partial Nephrectomy

More than ever, precision surgery is making its way into modern surgery for functional organ preservation. This is possible mainly due to the increasing number of technologies available, including 3D models, virtual reality, augmented reality, and artificial intelligence. Intraoperative surgical navigation represents an interesting application of these technologies, allowing to understand in detail the surgical anatomy, planning a patient-tailored approach. Automatic superimposition comes into this context to optimally perform surgery as accurately as possible. Through a dedicated software (the first version) called iKidney, it is possible to superimpose the images using 3D models and live endoscopic images during partial nephrectomy, targeting the renal mass only. The patient is 31 years old with a 28 mm totally endophytic right-sided renal mass, with a PADUA score of 9. Thanks to the automatic superimposition and selective clamping, an enucleoresection of the renal mass alone was performed with no major postoperative complication (i.e., Clavien-Dindo < 2). iKidney-guided partial nephrectomy is safe, feasible, and yields excellent results in terms of organ preservation and functional outcomes. Further validation studies are needed to improve the prototype software, particularly to improve the rotational axes and avoid human help. Furthermore, it is important to reduce the costs associated with these technologies to increase its use in smaller hospitals.

[Intervention planning in modern renal surgery]

BACKGROUND

Three-dimensional (3D) reconstruction in renal surgery offers significant benefits in planning of the operation itself, in patient education and training fellows.

OBJECTIVE

The goal was to study the possible application and use of 3D reconstruction in modern renal surgery.

METHODS

A literature search in PubMed using keywords "3D" and "renal surgery" within the last 10 years of publication was performed.

RESULTS

The search revealed 655 articles among them 53 reviews. Relevant for this article were 120 articles which included 14 reviews. The publication statistics showed a strong increase in the last 10 years which may reflect the increasing application and demand for 3D technology in the field of renal surgery. Especially in robot-assisted minimally invasive surgery applications, the use of 3D technology was studied more often. The technical standards are not yet uniform and 3D printing in complex renal surgery remains cost- and time-intensive. Nevertheless, the results of the pioneering clinical studies showed positive results, and 3D technology can be used not only in planning the operation, but in patient education and also the training of fellows and staff. A limitation to more complex cases seems to be sensible for this is still a costly tool. To identify complex cases in renal surgery, the established renometric scoring systems should be used more broadly in daily practice to identify patients who would profit most from this technique.

CONCLUSION

In complex renal surgery, 3D reconstruction and modelling is rational; furthermore, it can be useful in patient education and in training of fellows.

Health Information Technology Usability Evaluation Scale (Health-ITUES) and User-Experience Questionnaire (UEQ) for 3D Intraoperative Cognitive Navigation (ICON3DTM) System for Urological Procedures

Backgound and objectives: In recent years, the adoption of 3D models for surgical planning and intraoperative guidance has gained a wide diffusion. The aim of this study was to evaluate the surgeons' perception and usability of ICON3D^TM platform for robotic and laparoscopic urological surgical procedures. Materials and Methods: During the 10th edition of the Techno-Urology Meeting, surgeons and attendees had the opportunity to test the new ICON3D^TM platform. The capability of the user to manipulate the model with hands/mouse, the software usability, the quality of the 3D model's reproduction, and the quality of its use during the surgery were evaluated with the Health Information Technology Usability Evaluation Scale (Health-ITUES) and the User-Experience Questionnaire (UEQ). Results: Fifty-three participants responded to the questionnaires. Based on the answers to the Health-ITUES questionnaire, ICON3D^TM resulted to have a positive additional value in presurgical/surgical planning with 43.4% and 39.6% of responders that rated 4 (agree) and 5 (strongly agree), respectively. Regarding the UEQ questionnaire, both mouse and infrared hand-tracking system resulted to be easy to use for 99% of the responders, while the software resulted to be easy to use for 93.4% of the responders. Conclusions: In conclusion, ICON3D^TM has been widely appreciated by urologists thanks to its various applications, from preoperative planning to its support for intraoperative decision-making in both robot-assisted and laparoscopic settings.

Advances in percutaneous renal puncture: a comprehensive review of the literature

PURPOSE OF REVIEW

Percutaneous nephrolithotomy (PCNL) constitutes the gold standard procedure for patients suffering from more than 2 cm renal stones. The puncture is a very critical step of PCNL, affecting manoeuvrability of the nephroscope, possibility to remove stone fragments, risk of bleeding and radiation exposure. The aim of the current review was to discuss the advances in percutaneous renal puncture.

RECENT FINDINGS

Following technological evolution in medicine, there was a consistent development in the puncture techniques, aiming at the improvement of its efficacy and safety. The use of specific agents can improve ultrasonic guidance, making the challenging step of gaining access to the kidney easier for the experienced surgeon and more accessible for the resident urologist. Future developments in the electromagnetic and three-dimensional (3D) technology may establish a high level of accuracy with decreased rates of related complications, even in the hands of beginners.

SUMMARY

The advances in percutaneous puncture can lead to improved safety and accuracy of this procedure decreasing the radiation exposure and the complication rate.

The impact of extended reality on surgery: a scoping review

PURPOSE

Extended reality (XR) is defined as a spectrum of technologies that range from purely virtual environments to enhanced real-world environments. In the past two decades, XR-assisted surgery has seen an increase in its use and also in research and development. This scoping review aims to map out the historical trends in these technologies and their future prospects, with an emphasis on the reported outcomes and ethical considerations on the use of these technologies.

METHODS

A systematic search of PubMed, Scopus, and Embase for literature related to XR-assisted surgery and telesurgery was performed using Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) guidelines. Primary studies, peer-reviewed articles that described procedures performed by surgeons on human subjects and cadavers, as well as studies describing general surgical education, were included. Non-surgical procedures, bedside procedures, veterinary procedures, procedures performed by medical students, and review articles were excluded. Studies were classified into the following categories: impact on surgery (pre-operative planning and intra-operative navigation/guidance), impact on the patient (pain and anxiety), and impact on the surgeon (surgical training and surgeon confidence).

RESULTS

One hundred and sixty-eight studies were included for analysis. Thirty-one studies investigated the use of XR for pre-operative planning concluded that virtual reality (VR) enhanced the surgeon's spatial awareness of important anatomical landmarks. This leads to shorter operating sessions and decreases surgical insult. Forty-nine studies explored the use of XR for intra-operative planning. They noted that augmented reality (AR) headsets highlight key landmarks, as well as important structures to avoid, which lowers the chance of accidental surgical trauma. Eleven studies investigated patients' pain and noted that VR is able to generate a meditative state. This is beneficial for patients, as it reduces the need for analgesics. Ten studies commented on patient anxiety, suggesting that VR is unsuccessful at altering patients' physiological parameters such as mean arterial blood pressure or cortisol levels. Sixty studies investigated surgical training whilst seven studies suggested that the use of XR-assisted technology increased surgeon confidence.

CONCLUSION

The growth of XR-assisted surgery is driven by advances in hardware and software. Whilst augmented virtuality and mixed reality are underexplored, the use of VR is growing especially in the fields of surgical training and pre-operative planning. Real-time intra-operative guidance is key for surgical precision, which is being supplemented with AR technology. XR-assisted surgery is likely to undertake a greater role in the near future, given the effect of COVID-19 limiting physical presence and the increasing complexity of surgical procedures.

Preoperative patient optimization for endourological procedures: the current best clinical practice

PURPOSE OF REVIEW

Despite technological advancements in endourological surgery, there is room for improvement in preoperative patient optimization strategies. This review updates recent best clinical practices that can be implemented for optimal surgical outcomes.

RECENT FINDINGS

Outcome and complication predictions using novel scoring systems and techniques have shown to assist clinical decision-making and patient counseling. Innovative preoperative simulation and localization methods for percutaneous nephrolithotomy have been evaluated to minimize puncture-associated adverse events. Novel antibiotic prophylaxis strategies and further recognition of risk factors that attribute to postoperative infections have shown the potential to minimize perioperative morbidity. Accumulating data on the roles of preoperative stenting and selective oral alpha-blockers adds evidence to the current paradigm of preventive measures for ureteral injury.

SUMMARY

Ample tools and technologies exist that can be utilized preoperatively to improve surgical outcomes. The combination of these innovations, along with validation in larger-scale studies, presents the cornerstone of future urolithiasis management.

Real-time mixed reality display of dual particle radiation detector data

Radiation source localization and characterization are challenging tasks that currently require complex analyses for interpretation. Mixed reality (MR) technologies are at the verge of wide scale adoption and can assist in the visualization of complex data. Herein, we demonstrate real-time visualization of gamma ray and neutron radiation detector data in MR using the Microsoft HoloLens 2 smart glasses, significantly reducing user interpretation burden. Radiation imaging systems typically use double-scatter events of gamma rays or fast neutrons to reconstruct the incidence directional information, thus enabling source localization. The calculated images and estimated 'hot spots' are then often displayed in 2D angular space projections on screens. By combining a state-of-the-art dual particle imaging system with HoloLens 2, we propose to display the data directly to the user via the head-mounted MR smart glasses, presenting the directional information as an overlay to the user's 3D visual experience. We describe an open source implementation using efficient data transfer, image calculation, and 3D engine. We thereby demonstrate for the first time a real-time user experience to display fast neutron or gamma ray images from various radioactive sources set around the detector. We also introduce an alternative source search mode for situations of low event rates using a neural network and simulation based training data to provide a fast estimation of the source's angular direction. Using MR for radiation detection provides a more intuitive perception of radioactivity and can be applied in routine radiation monitoring, education & training, emergency scenarios, or inspections.

Mixed-Reality-Assisted Puncture of the Common Femoral Artery in a Phantom Model

Percutaneous femoral arterial access is daily practice in a variety of medical specialties and enables physicians worldwide to perform endovascular interventions. The reported incidence of percutaneous femoral arterial access complications is 3–18% and often results from suboptimal puncture location due to insufficient visualization of the target vessel. The purpose of this proof-of-concept study was to evaluate the feasibility and the positional error of a mixed-reality (MR)-assisted puncture of the common femoral artery in a phantom model using a commercially available navigation system. In total, 15 MR-assisted punctures were performed. Cone-beam computed tomography angiography (CTA) was used following each puncture to allow quantification of positional error of needle placements in the axial and sagittal planes. Technical success was achieved in 14/15 cases (93.3%) with a median axial positional error of 1.0 mm (IQR 1.3) and a median sagittal positional error of 1.1 mm (IQR 1.6). The median duration of the registration process and needle insertion was 2 min (IQR 1.0). MR-assisted puncture of the common femoral artery is feasible with acceptable positional errors in a phantom model. Future studies should aim to measure and reduce the positional error resulting from MR registration.

Pediatric Urolithiasis: Current Surgical Strategies and Future Perspectives

New technological innovations and cutting-edge techniques have led to important changes in the surgical management of pediatric urolithiasis. Miniaturized technologies and minimally invasive approaches have been increasingly used in children with urinary stones to minimize surgical complications and improve patient outcomes. Moreover, the new computer technologies of the digital era have been opening new horizons for the preoperative planning and surgical treatment of children with urinary calculi. Three-dimensional modeling reconstructions, virtual, augmented, and mixed reality are rapidly approaching the surgical practice, equipping surgeons with powerful instruments to enhance the real-time intraoperative visualization of normal and pathological structures. The broad range of possibilities offered by these technological innovations in the adult population finds increasing applications in pediatrics, offering a more detailed visualization of small anatomical structures. This review illustrates the most promising techniques and devices to enhance the surgical treatment of pediatric urolithiasis in children, aiming to favor an early adoption and to stimulate more research on this topic.