Effect of 3-Dimensional Virtual Reality Models for Surgical Planning of Robotic-Assisted Partial Nephrectomy on Surgical Outcomes: A Randomized Clinical Trial

Parathyroidectomy for solitary parathyroid adenoma via trans-areola single site endoscopic approach: Results of a case-match study

BACKGROUND

This study aimed to establish the standardized procedure of trans-areola single site endoscopic parathyroidectomy (TASSEP), and to compare the performance of TASSEP with that of conventional open parathyroidectomy (COP).

METHODS

This study enrolled 40 patients with primary hyperparathyroidism (PHPT) who underwent TASSEP, and included 40 of 176 PHPT patients who underwent COP based on propensity score matching. The retrospective analysis was conducted based on prospectively collected data. Perioperative outcomes, including surgical profile, surgical burden and cosmetic results and follow-up were reported. The learning curve was described using a cumulative sum (CUSUM) analysis.

RESULTS

40 TASSEPs were completed successfully without conversions or severe complications. There was no statistically significant difference in operation time between TASSEP and COP groups (80.83 ± 11.95 vs. 76.95 ± 7.30 min, p = 0.084). Experience of 17 cases was necessitated to reach the learning curve of TASSEP. Postoperative pain score and traumatic index (C-reactive protein and erythrocyte sedimentation rate) in TASSEP were apparently lower than those in COP group (p < 0.05). During the proliferation and stabilization phases, TASSEP was associated with significantly better incision recovery and cosmetic scores. Postoperative serum calcium and PTH levels throughout the follow-up period indicated satisfactory surgical qualities in both groups.

CONCLUSION

Based on precise preoperative localization and intraoperative planning facilitated by three-dimensional (3D) virtual modeling, TASSEP can be feasibly performed on selected patients with satisfactory success rates and low complication rates, providing preferable cosmetic results and alleviating the surgical burden to a certain extent.

Intraoperative image-guidance during robotic surgery: is there clinical evidence of enhanced patient outcomes?

BACKGROUND

To date, the benefit of image guidance during robot-assisted surgery (IGS) is an object of debate. The current study aims to address the quality of the contemporary body of literature concerning IGS in robotic surgery throughout different surgical specialties.

METHODS

A systematic review of all English-language articles on IGS, from January 2013 to March 2023, was conducted using PubMed, Cochrane library's Central, EMBASE, MEDLINE, and Scopus databases. Comparative studies that tested performance of IGS vs control were included for the quantitative synthesis, which addressed outcomes analyzed in at least three studies: operative time, length of stay, blood loss, surgical margins, complications, number of nodal retrievals, metastatic nodes, ischemia time, and renal function loss. Bias-corrected ratio of means (ROM) and bias-corrected odds ratio (OR) compared continuous and dichotomous variables, respectively. Subgroup analyses according to guidance type (i.e., 3D virtual reality vs ultrasound vs near-infrared fluoresce) were performed.

RESULTS

Twenty-nine studies, based on 11 surgical procedures of three specialties (general surgery, gynecology, urology), were included in the quantitative synthesis. IGS was associated with 12% reduction in length of stay (ROM 0.88; p = 0.03) and 13% reduction in blood loss (ROM 0.87; p = 0.03) but did not affect operative time (ROM 1.00; p = 0.9), or complications (OR 0.93; p = 0.4). IGS was associated with an estimated 44% increase in mean number of removed nodes (ROM 1.44; p < 0.001), and a significantly higher rate of metastatic nodal disease (OR 1.82; p < 0.001), as well as a significantly lower rate of positive surgical margins (OR 0.62; p < 0.001). In nephron sparing surgery, IGS significantly decreased renal function loss (ROM 0.37; p = 0.002).

CONCLUSIONS

Robot-assisted surgery benefits from image guidance, especially in terms of pathologic outcomes, namely higher detection of metastatic nodes and lower surgical margins. Moreover, IGS enhances renal function preservation and lowers surgical blood loss.

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.

Three-dimensional computed tomography-based resection process map for robot-assisted partial nephrectomy: propensity score matching of a single-center retrospective study

BACKGROUND AND OBJECTIVES

We aimed to examine the effect of preoperative three-dimensional (3D) computed tomography (CT)-based resection process map (RPM) imaging on the outcomes of robot-assisted partial nephrectomy (RAPN).

METHODS

We retrospectively analyzed 177 patients (RPM group, n = 92; non-RPM group, n = 85) who underwent this surgery between November 2012 and April 2022. Patient-specific contrast-enhanced CT images were used to construct an RPM, a 3D representation of the kidney showing the planned tumor resection and a 5 mm safety margin. Outcome analyses were performed using propensity score matching. The primary endpoint was the trifecta achievement rate.

RESULTS

We extracted 90 cases. The trifecta achievement rate showed no significant differences between the RPM (73.3%) and non-RPM groups (73.3%). However, the RPM group had fewer Grade 3 and higher complications (0.0% vs. 13.3%, p = 0.026). The da Vinci Xi (OR 3.38, p = 0.016) and tumor diameter (OR 0.95, p = 0.013) were independent factors affecting trifecta achievement in multivariate analysis. Using RPM imaging was associated with the absence of Grade 3 and higher perioperative complications (OR 5.33, p = 0.036) in univariate analysis.

CONCLUSIONS

Using preoperative 3D CT-based RPM images before RAPN may not affect trifecta achievement, but may reduce serious complication occurrence by providing detailed information on tumor resection.

Association between 3D membranous urethral parameters and urinary continence recovery after RARP

OBJECTIVES

To evaluate whether the urinary continence (UC) recovery after robotic-assisted radical prostatectomy (RARP) relates to the membranous urethral length (MUL) and the membranous urethral complex volume (MUV).

MATERIALS AND METHODS

120 patients who underwent RARP were enrolled according to the different times of UC recovery and examined using prostate magnetic resonance imaging (MRI) before surgery. The membranous urethral (MU) parameters were measured using the three-Dimensional (3D) model reconstructed by holographic technology, such as total MUV (tMUV), exposed MUV (eMUV), full MUL (fMUL) and exposed MUL (eMUL). Statistical software SPSS 26.0 was used to analyze the data and compare the MU parameters and baseline data in different groups.

RESULTS

Patients with larger tMUV (p = 0.038), eMUV (p = 0.003), longer fMUL (p = 0.025), eMUL (p = 0.044) had better UC after removal of the catheter, and eMUV (OR = 1.002, 95%CI = 1.001-1.004, p = 0.004) was a predictor; the patients with younger age (p = 0.021), lower VPSS score (p = 0.004) and larger eMUV (p = 0.012) and longer eMUL (p = 0.049) had better UC recovery one month after RARP while eMUV (OR = 1.002, 95% CI = 1.000-1.003, p = 0.008) and VPSS score (OR = 0.886, 95% CI = 0.806-0.973, p = 0.011) were independent risk factors; The patients with younger age (p = 0.018), larger tMUV (p = 0.029), eMUV (p = 0.016) had better UC recovery three months after RARP. eMUV (OR = 1.002, 95% CI = 1.000-1.004, p = 0.042) and age (OR = 0.904, 95% CI = 0.818-0.998, p = 0.046) were independent risk factors.

CONCLUSION

This clinical study shows that patients with larger MUV and longer MUL can return to UC earlier after surgery. Among that, eMUV is a better predictor.

SpecReFlow: an algorithm for specular reflection restoration using flow-guided video completion

Purpose

Specular reflections (SRs) are highlight artifacts commonly found in endoscopy videos that can severely disrupt a surgeon's observation and judgment. Despite numerous attempts to restore SR, existing methods are inefficient and time consuming and can lead to false clinical interpretations. Therefore, we propose the first complete deep-learning solution, SpecReFlow, to detect and restore SR regions from endoscopy video with spatial and temporal coherence.

Approach

SpecReFlow consists of three stages: (1) an image preprocessing stage to enhance contrast, (2) a detection stage to indicate where the SR region is present, and (3) a restoration stage in which we replace SR pixels with an accurate underlying tissue structure. Our restoration approach uses optical flow to seamlessly propagate color and structure from other frames of the endoscopy video.

Results

Comprehensive quantitative and qualitative tests for each stage reveal that our SpecReFlow solution performs better than previous detection and restoration methods. Our detection stage achieves a Dice score of 82.8% and a sensitivity of 94.6%, and our restoration stage successfully incorporates temporal information with spatial information for more accurate restorations than existing techniques.

Conclusions

SpecReFlow is a first-of-its-kind solution that combines temporal and spatial information for effective detection and restoration of SR regions, surpassing previous methods relying on single-frame spatial information. Future work will look to optimizing SpecReFlow for real-time applications. SpecReFlow is a software-only solution for restoring image content lost due to SR, making it readily deployable in existing clinical settings to improve endoscopy video quality for accurate diagnosis and treatment.

Optimizing Surgical Efficiency in Complex Spine Surgery Using Virtual Reality as a Communication Technology to Promote a Shared Mental Model: A Case Series and Review

BACKGROUND AND OBJECTIVES

Virtual reality (VR) is an emerging technology that can be used to promote a shared mental model among a surgical team. We present a case series demonstrating the use of 3-dimensional (3D) VR models to visually communicate procedural steps to a surgical team to promote a common operating objective. We also review the literature on existing uses of VR for preoperative communication and planning in spine surgery.

METHODS

Narrations of 3 to 4-minute walkthroughs were created in a VR visualization platform, converted, and distributed to team members through text and email the night before surgical intervention. A VR huddle was held immediately before the intervention to refine surgical goals. After the intervention, the participating team members' perceptions on the value of the tool were assessed using a survey that used a 5-point Likert scale. MEDLINE, Google Scholar, and Dimensions AI databases were queried from July 2010 to October 2022 to examine existing literature on preoperative VR use to plan spine surgery.

RESULTS

Three illustrative cases are presented with accompanying video. Postoperative survey results demonstrate a positive experience among surgical team members after reviewing preoperative plans created with patient-specific 3D VR models. Respondents felt that preoperative VR video review was "moderately useful" or more useful in improving their understanding of the operational sequence (71%, 5/7), in enhancing their ability to understand their role (86%, 6/7), and in improving the safety or efficiency of the case (86%, 6/7).

CONCLUSION

We present a proof of concept of a novel preoperative communication tool used to create a shared mental model of a common operating objective for surgical team members using narrated 3D VR models. Initial survey results demonstrate positive feedback among respondents. There is a paucity of literature investigating VR technology as a means for preoperative surgical communication in spine surgery.

ETHICS

Institutional review board approval (IRB-300009785) was obtained before this study.

Assessment of resectability of pancreatic cancer using novel immersive high-performance virtual reality rendering of abdominal computed tomography and magnetic resonance imaging

PURPOSE

Virtual reality (VR) allows for an immersive and interactive analysis of imaging data such as computed tomography (CT) and magnetic resonance imaging (MRI). The aim of this study is to assess the comprehensibility of VR anatomy and its value in assessing resectability of pancreatic ductal adenocarcinoma (PDAC).

METHODS

This study assesses exposure to VR anatomy and evaluates the potential role of VR in assessing resectability of PDAC. Firstly, volumetric abdominal CT and MRI data were displayed in an immersive VR environment. Volunteering physicians were asked to identify anatomical landmarks in VR. In the second stage, experienced clinicians were asked to identify vascular involvement in a total of 12 CT and MRI scans displaying PDAC (2 resectable, 2 borderline resectable, and 2 locally advanced tumours per modality). Results were compared to 2D standard PACS viewing.

RESULTS

In VR visualisation of CT and MRI, the abdominal anatomical landmarks were recognised by all participants except the pancreas (30/34) in VR CT and the splenic (31/34) and common hepatic artery (18/34) in VR MRI, respectively. In VR CT, resectable, borderline resectable, and locally advanced PDAC were correctly identified in 22/24, 20/24 and 19/24 scans, respectively. Whereas, in VR MRI, resectable, borderline resectable, and locally advanced PDAC were correctly identified in 19/24, 19/24 and 21/24 scans, respectively. Interobserver agreement as measured by Fleiss κ was 0.7 for CT and 0.4 for MRI, respectively (p < 0.001). Scans were significantly assessed more accurately in VR CT than standard 2D PACS CT, with a median of 5.5 (IQR 4.75-6) and a median of 3 (IQR 2-3) correctly assessed out of 6 scans (p < 0.001).

CONCLUSION

VR enhanced visualisation of abdominal CT and MRI scan data provides intuitive handling and understanding of anatomy and might allow for more accurate staging of PDAC and could thus become a valuable adjunct in PDAC resectability assessment in the future.

Developing a Virtual Reality Simulation System for Preoperative Planning of Robotic-Assisted Thoracic Surgery

Background. Robotic-assisted thoracic surgery (RATS) is now standard for lung cancer treatment, offering advantages over traditional methods. However, RATS's minimally invasive approach poses challenges like limited visibility and tactile feedback, affecting surgeons' navigation through com-plex anatomy. To enhance preoperative familiarization with patient-specific anatomy, we devel-oped a virtual reality (VR) surgical navigation system. Using head-mounted displays (HMDs), this system provides a comprehensive, interactive view of the patient's anatomy pre-surgery, aiming to improve preoperative simulation and intraoperative navigation. Methods. We integrated 3D data from preoperative CT scans into Perspectus VR Education software, displayed via HMDs for in-teractive 3D reconstruction of pulmonary structures. This detailed visualization aids in tailored preoperative resection simulations. During RATS, surgeons access these 3D images through Tile-ProTM multi-display for real-time guidance. Results. The VR system enabled precise visualization of pulmonary structures and lesion relations, enhancing surgical safety and accuracy. The HMDs offered true 3D interaction with patient data, facilitating surgical planning. Conclusions. VR sim-ulation with HMDs, akin to a robotic 3D viewer, offers a novel approach to developing robotic surgical skills. Integrated with routine imaging, it improves preoperative planning, safety, and accuracy of anatomical resections. This technology particularly aids in lesion identification in RATS, optimizing surgical outcomes.

Preoperative planning using virtual reality and computed tomography angiogram in deep inferior epigastric perforator flap breast reconstruction

The gold standard for preoperative planning of deep inferior epigastric perforator (DIEP) flap breast reconstruction uses computed tomography angiography (CTA). Virtual reality (VR) circumnavigates the limitations of CTA by reconstructing a fully immersive and interactive 3D representation of the scan. Scans of 44 patients who underwent DIEP flap breast reconstruction were retrospectively reviewed and compared using CTA and VR imaging modalities. The objective of this research was to compare perforators found using VR to the ones identified using conventional CTA. A correlation was found between the imaging modalities for unilateral (R = 0.96 (CI = 0.92, 0.98)) and bilateral (R = 0.93, (CI = 0.83, 0.97)) DIEP flap surgeries when comparing perforator location related to the umbilicus. Multivariable ordinal logistic regression found that higher intramuscular course length (IMC) is associated with the number of perforators found per side (OR = 1.79 (CI = 1.24, 2.6)), and medial location (OR = 2.85 (CI = 1.38, 5.87)). Larger vessel caliber (VC) is associated with shorter IMC (T2 vs. T3, OR = 3.34 (CI = 1.49, 7.49)), and branching in adipose tissue (AB) is associated with higher VC (T1 vs. T3, OR = 0.02 (CI = 0.007, 0.08); T2 vs. T3, OR = 0.24 (CI = 0.11, 0.55)). Overall, preoperative planning using VR was easy to use, safe, more intuitive, and provided in a time-efficient manner, more information about perforant characteristics. VR can improve the surgeon's decision accuracy, relating to the best perforators for harvesting, in a shorter time period.

Patient-specific simulations and navigation systems for partial nephrectomy

Partial nephrectomy (PN) is the standard treatment for T1 renal cell carcinoma. PN is affected more by surgical variations and requires greater surgical experience than radical nephrectomy. Patient-specific simulations and navigation systems may help to reduce the surgical experience required for PN. Recent advances in three-dimensional (3D) virtual reality (VR) imaging and 3D printing technology have allowed accurate patient-specific simulations and navigation systems. We reviewed previous studies about patient-specific simulations and navigation systems for PN. Recently, image reconstruction technology has developed, and commercial software that converts two-dimensional images into 3D images has become available. Many urologists are now able to view 3DVR images when preparing for PN. Surgical simulations based on 3DVR images can change surgical plans and improve surgical outcomes, and are useful during patient consultations. Patient-specific simulators that are capable of simulating surgical procedures, the gold-standard form of patient-specific simulations, have also been reported. Besides VR, 3D printing is also useful for understanding patient-specific information. Some studies have reported simulation and navigation systems for PN based on solid 3D models. Patient-specific simulations are a form of preoperative preparation, whereas patient-specific navigation is used intraoperatively. Navigation-assisted PN procedures using 3DVR images have become increasingly common, especially in robotic surgery. Some studies found that these systems produced improvements in surgical outcomes. Once its accuracy has been confirmed, it is hoped that this technology will spread further and become more generalized.

Optimizing Surgical Performance Using Preoperative Virtual Reality Planning: A Systematic Review

BACKGROUND

Surgery is often a complex process that requires detailed 3-dimensional anatomical knowledge and rigorous interplay between team members to attain ideal operational efficiency or "flow." Virtual Reality (VR) represents a technology by which to rehearse complex plans and communicate precise steps to a surgical team prior to entering the operating room. The objective of this study was to evaluate the use of VR for preoperative surgical team planning and interdisciplinary communication across all surgical specialties.

METHODS

A systematic review of the literature was performed examining existing research on VR use for preoperative surgical team planning and interdisciplinary communication across all surgical fields in order to optimize surgical efficiency. MEDLINE, SCOPUS, CINAHL databases were searched from inception to July 31, 2022 using standardized search clauses. A qualitative data synthesis was performed with particular attention to preoperative planning, surgical efficiency optimization, and interdisciplinary collaboration/communication techniques determined a priori. Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines were followed. All included studies were appraised for their quality using the Medical Education Research Study Quality Instrument (MERSQI) tool.

RESULTS

One thousand and ninety-three non-duplicated articles with abstract and full text availability were identified. Thirteen articles that examined preoperative VR-based planning techniques for optimization of surgical efficiency and/or interdisciplinary communication fulfilled inclusion and exclusion criteria. These studies had a low-to-medium methodological quality with a MERSQI mean score of 10.04 out of 18 (standard deviation 3.61).

CONCLUSIONS

This review demonstrates that time spent rehearsing and visualizing patient-specific anatomical relationships in VR may improve operative efficiency and communication across multiple surgical specialties.

Three-dimensional Virtual Models of the Kidney with Colored Perfusion Regions: A New Algorithm-based Tool for Optimizing the Clamping Strategy During Robot-assisted Partial Nephrectomy

BACKGROUND

An empirical selective clamping strategy based on the direction of the arterial branches can lead to failures during partial nephrectomy, even when assisted by three-dimensional virtual models (3DVMs).

OBJECTIVE

To develop and test new 3DVMs that include kidney perfusion regions and evaluate their intraoperative accuracy in guiding selective clamping and their impact on postoperative renal function.

DESIGN, SETTING, AND PARTICIPANTS

For patients with a kidney suitable for nephron-sparing surgery, 3DVMs were supplemented with a Voronoi diagram, a Euclidean distance-based mathematical tool, to calculate vascular-dominant regions the kidney.

SURGICAL PROCEDURE

Robot-assisted partial nephrectomy guided by perfusion-region (PR)-3DVMs.

MEASUREMENTS

All anatomic information given by the PR-3DVMs was collected. Selective or superselective clamping was planned and performed intraoperatively when feasible under 3DVM assistance. Changes in split renal function (SRF) and estimated renal plasmatic flow (ERPF) were evaluated for 51 patients who underwent baseline and 3-mo postoperative renal scintigraphy.

RESULTS AND LIMITATIONS

A total of 103 patients were prospectively enrolled. The median number of kidney and tumor perfusion regions were 8 (interquartile range [IQR] 7-10) and 3 (IQR 2-3), respectively. A clampless, selective clamping, and global clamping strategy was applied in eight (7.8%), 79 (76.6%), and 16 (15.5%) cases, respectively, with no differences between planning and surgery in terms of the number or order of arteries clamped or the perfusion regions that underwent ischemia. Among the 51 patients who underwent renal scintigraphy, the mean SRF decreased by 11.3%, 7.7%, and 1.7% after global, selective, and superselective clamping, respectively (p = 0.004). Similar results were obtained for ERPF (18.9%, 9.9%, and 6.0%; p = 0.02). The main limitation is the need for a bioengineer to manually refine the 3DVMs.

CONCLUSIONS

Use of mathematical algorithms for 3DVMs allows precise estimation of kidney perfusion regions to maximize the efficacy of selective clamping and minimize renal function impairment.

PATIENT SUMMARY

Three-dimensional models that include regions of blood flow to the kidney can be used to guide clamping of blood vessels when part of the kidney is being surgically removed. More limited clamping can reduce damage to the remaining portion of the kidney and result in better recovery of kidney function after surgery.

Three-Dimensional Customized Imaging Reconstruction for Urological Surgery: Diffusion and Role in Real-Life Practice from an International Survey

Despite the arising interest in three-dimensional (3D) reconstruction models from 2D imaging, their diffusion and perception among urologists have been scarcely explored. The aim of the study is to report the results of an international survey investigating the use of such tools among urologists of different backgrounds and origins. Beyond demographics, the survey explored the degree to which 3D models are perceived to improve surgical outcomes, the procedures mostly making use of them, the settings in which those tools are mostly applied, the surgical steps benefiting from 3D reconstructions and future perspectives of improvement. One hundred responders fully completed the survey. All levels of expertise were allowed; more than half (53%) were first surgeons, and 59% had already completed their training. Their main application was partial nephrectomy (85%), followed by radical nephrectomy and radical prostatectomy. Three-dimensional models are mostly used for preoperative planning (75%), intraoperative consultation and tailoring. More than half recognized that 3D models may highly improve surgical outcomes. Despite their recognized usefulness, 77% of responders use 3D models in less than 25% of their major operations due to costs or the extra time taken to perform the reconstruction. Technical improvements and a higher availability of the 3D models will further increase their role in surgical and clinical daily practice.

Left atrial appendage sizing for percutaneous closure in virtual reality-a feasibility study

Background and aims

The complex and highly variable three-dimensional anatomy of the left atrial appendage (LAA) makes planning and device sizing for interventional occlusion procedures (LAAC) challenging. Several imaging modalities [e.g. echocardiography, multi-slice computed tomography (MSCT)] are used for this purpose. Virtual reality (VR) is an emerging imaging technique to immerse into a three-dimensional left atrium and appendage, offering unprecedented options of visualization and measurement. This study aimed to investigate the feasibility, accuracy and reproducibility of visualizing the LAA in VR for preprocedural planning of LAAC.

Methods and results

Twenty-one patients (79 ± 7 years, 62% male) who underwent LAAC at University Hospital Düsseldorf were included in our study. A dedicated software generated three-dimensional VR models from preprocedural MSCT imaging data. Conventional measurements of LAA dimensions (ostium, landing zone and depth) using a commercially available software were compared to measurements in VR: MSCT and VR ostium min. (r = 0.93), max. (r = 0.80) and mean (r = 0.88, all p < 0.001) diameters as well as landing zone (LZ) min. (r = 0.84), max. (r = 0.86) and mean diameters (r = 0.90, all p < 0.001) showed strong correlations. Three-dimensional orientation was judged superior by physicians in VR compared to MSCT (p < 0.05).

Conclusion

Virtual reality visualization of the left atrium and appendage based on MSCT data is feasible and allows precise and reproducible measurements in planning of LAA occlusion procedures with enhanced 3D orientation. Further studies need to explore additional benefits of three-dimensional visualization for operators in preprocedural planning.

Robotic Partial vs Radical Nephrectomy for Clinical T3a Tumors: A Narrative Review

Introduction: T3a renal masses include a diverse group of tumors that invade the perirenal and/or sinus fat, pelvicaliceal system, or renal vein. The majority of cT3a renal masses represent renal cell carcinoma (RCC) and have historically been treated with radical nephrectomy (RN) given their aggressive nature. With the adoption of minimally invasive approaches to renal surgery, the combination of improved observation, pneumoperitoneum, and robotic articulation has allowed urologists to consider partial nephrectomy (PN) for more complex tumors. Herein, we review the existing literature regarding robot-assisted PN (RAPN) and robot-assisted RN (RARN) in the management of T3a renal masses. Methods: A literature search was performed using PubMed for articles evaluating the role of RARN and RAPN for T3a renal masses. Search parameters were limited to English language studies. Applicable studies were abstracted and included in this narrative review. Results: T3a RCC caused by renal sinus fat or venous involvement is associated with ∼50% lower cancer-specific survival than those with perinephric fat invasion alone. CT and MRI can both be used to stage cT3a tumors, however, MRI is more accurate when assessing venous involvement. Upstaging to pT3a RCC during RAPN does not confer a worse prognosis than pT3a tumors treated with RARN; however, patients who undergo RAPN for T3a RCC with venous involvement have relatively higher rates of recurrence and metastasis. Intraoperative tools including drop-in ultrasound, near-infrared fluorescence, and 3D virtual models improve the ability to perform RAPN for T3a tumors. In well-selected cases, warm ischemia times remain reasonable. Conclusions: cT3a renal masses represent a diverse group of tumors. Depending on substratification of cT3a, RARN or RAPN can be employed for treatment of such masses.

Long-Term Renal Function Following Renal Cancer Surgery: Historical Perspectives, Current Status, and Future Considerations

Knowledge of functional recovery after partial (PN) and radical nephrectomy for renal cancer has advanced considerably, with PN now established as the reference standard for most localized renal masses. However, it is still unclear whether PN provides an overall survival benefit in patients with a normal contralateral kidney. While early studies seemingly demonstrated the importance of minimizing warm-ischemia time during PN, multiple new investigations over the last 10 years have proven that parenchymal mass lost is the most important predictor of new baseline renal function. Minimizing loss of parenchymal mass during resection and reconstruction is the most important controllable aspect of long-term post-operative renal function preservation.

The Value of Three-Dimensional Printing Spine Model in Severe Spine Deformity Correction Surgery

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

We aimed to evaluate the value of 3-dimensional printing (3DP) spine model in the surgical treatment of severe spinal deformity since the prosperous development of 3DP technology.

METHODS

Severe scoliosis or hyper-kyphosis patients underwent posterior fixation and fusion surgery using the 3DP spine models were reviewed (3DP group). Spinal deformity surgeries operated by free-hand screw implantation during the same period were selected as the control group after propensity score matching (PSM). The correction rate, pedicle screw accuracy, and complications were analyzed. Class A and B screws were defined as accurate according to Gertzbein and Robbins criteria.

RESULTS

35 patients were enrolled in the 3DP group and 35 matched cases were included in the control group. The perioperative baseline data and deformity correction rate were similar between both groups (P > .05). However, the operation time and blood loss were significantly less in the 3DP group (296.14 ± 66.18 min vs. 329.43 ± 67.16 min, 711.43 ± 552.28 mL vs. 1322.29 ± 828.23 mL, P < .05). More three-column osteotomies (Grade 3-6) were performed in the 3DP group (30/35, 85.7% vs. 21/35, 60.0%. P = .016). The screw placement accuracy was significantly higher in the 3DP group (422/582, 72.51% vs. 397/575, 69.04%. P = .024). The screw misplacement related complication rate was significantly higher in the free-hand group (6/35 vs. 1/35, P = .046).

CONCLUSIONS

The study provided solid evidence that 3DP spine models can enhance surgeons' confidence in performing higher grade osteotomies and improve the safety and efficiency in severe spine deformity correction surgery. 3D printing technology has a good prospect in spinal deformity surgery.

Robotic versus Laparoscopic Partial Nephrectomy in the New Era: Systematic Review

(1) Background: In recent years there have been advances in imaging techniques, in addition to progress in the surgery of renal tumors directed towards minimally invasive techniques. Thus, nephron-sparing surgery has become the gold standard for the treatment of T1 renal masses. The aim of this study is to investigate the benefits of robotic partial nephrectomy in comparison with laparoscopic nephrectomy. (2) Methods: We performed a systematic review according to the PRISMA criteria during September 2022. We included clinical trials, and cohort and case-control studies published between 2000 and 2022. This comprised studies performed in adult patients with T1 renal cancer and studies comparing robotic with open and laparoscopic partial nephrectomy. A risk of bias assessment was performed according to the Newcastle—Ottawa scale. (3) Results: We observed lower hot ischemia times in the robotic surgery groups, although at the cost of an increase in total operative time, without appreciating the differences in terms of serious surgical complications (Clavien III–V). (4) Conclusions: Robotic partial nephrectomy is a safe procedure, with a shorter learning curve than laparoscopic surgery and with all the benefits of minimally invasive surgery.

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.

3D-Image guided robotic-assisted partial nephrectomy: a multi-institutional propensity score-matched analysis (UroCCR study 51)

PURPOSE

Robot-assisted partial nephrectomy (RAPN) is a difficult procedure with risk of significant perioperative complications. The objective was to evaluate the impact of preoperative planning and intraoperative guidance with 3D model reconstructions on perioperative outcomes of RAPN.

METHODS

We conducted a retrospective analysis of all patients who underwent RAPN for kidney tumor by three high-volume expert surgeons from academic centers. Clinical data were collected prospectively after written consent into the French kidney cancer network database UroCCR (CNIL-DR 2013-206; NCT03293563). Our cohort was divided into two groups: 3D-Image guided RAPN group (3D-IGRAPN) and control group. A propensity score according to age, pre-operative renal function and RENAL tumor complexity score was used. Both surgical techniques were compared in terms of perioperative outcomes.

RESULTS

The initial study cohort included 230 3D-IGRAPN and 415 control RAPN. Before propensity-score matching, patients in the 3D-IGRAPN group had a larger tumor (4.3 cm vs. 3.5 cm, P < 0.001) and higher RENAL complexity score (9 vs. 8, P < 0.001). Following propensity-score matching, there were 157 patients in both groups. The rate of major complications was lower for patients in the 3D-IGRAPN group (3.8% vs. 9.5%, P = 0.04). The median percentage of eGFR variation recorded at first follow-up was lower in the 3D-IGRAPN group (- 5.6% vs. - 10.5%, P = 0.002). The trifecta achievement rate was higher in the 3D-IGRAPN group (55.7% vs. 45.1%; P = 0.005).

CONCLUSION

Three-dimensional kidney reconstructions use for pre-operative planning and intraoperative surgical guidance lowers the risk of complications and improve perioperative clinical outcomes of RAPN.

Immersive Virtual Reality for Patient-Specific Preoperative Planning: A Systematic Review

Background. Immersive virtual reality (iVR) facilitates surgical decision-making by enabling surgeons to interact with complex anatomic structures in realistic 3-dimensional environments. With emerging interest in its applications, its effects on patients and providers should be clarified. This systematic review examines the current literature on iVR for patient-specific preoperative planning. Materials and Methods. A literature search was performed on five databases for publications from January 1, 2000 through March 21, 2021. Primary studies on the use of iVR simulators by surgeons at any level of training for patient-specific preoperative planning were eligible. Two reviewers independently screened titles, abstracts, and full texts, extracted data, and assessed quality using the Quality Assessment Tool for Studies with Diverse Designs (QATSDD). Results were qualitatively synthesized, and descriptive statistics were calculated. Results. The systematic search yielded 2,555 studies in total, with 24 full-texts subsequently included for qualitative synthesis, representing 264 medical personnel and 460 patients. Neurosurgery was the most frequently represented discipline (10/24; 42%). Preoperative iVR did not significantly improve patient-specific outcomes of operative time, blood loss, complications, and length of stay, but may decrease fluoroscopy time. In contrast, iVR improved surgeon-specific outcomes of surgical strategy, anatomy visualization, and confidence. Validity, reliability, and feasibility of patient-specific iVR models were assessed. The mean QATSDD score of included studies was 32.9%. Conclusions. Immersive VR improves surgeon experiences of preoperative planning, with minimal evidence for impact on short-term patient outcomes. Future work should focus on high-quality studies investigating long-term patient outcomes, and utility of preoperative iVR for trainees.

Better specificity and less ischemia: three-dimensional reconstruction is superior to routine computed tomography angiography in navigation of super-selective clamping robot-assisted laparoscopic partial nephrectomy

Background

Available technologies could be used to guide surgeons in controlling highly selective tumor-bearing arteries robot-assisted laparoscopic partial nephrectomy (RALPN).

Methods

Patients undergoing RALPN (from September 2018 to January 2020) for intermediate-high complex renal tumor (R.E.N.A.L. score ≥7) who underwent abdominal computed tomography (CT) scan with angiography and hyper-accuracy 3-dimensional reconstruction (H3DR). All patients underwent high-resolution CT scan with angiography and H3DR with special software, based on which two kinds of highly selective arterial clamp protocols were made for each patient and analyzed independently by two urologists and two radiologists to confirm which renal arterial branch was supplying the tumor. We chose the optimized clamping protocol with the principle of the minimized ischemic regions. During the operation, meticulous microdissection and clip ligation of the specific vascular branch was guided by optimized protocol [H3DR or computed tomography angiography (CTA) reconstruction], according to the in vivo anatomy (identified by intraoperative ultrasound).

Results

Of 82 patients, the minimum-ischemic regions planning completed rate (MIRPCR) of preoperative planning with H3DR (90.2%) was higher than that with CTA (34.1%) (P<0.01). H3DR identified 78 high-order arteries (70.3%), whereas CTA identified 33 (29.7%) high-order arteries (P<0.001). H3DR detected a more optimal blocking option in 51 cases that were either missed (n=13) or misclassified by CTA (n=38). A total of 18 cases (56.3%) were converted to H3DR-guided occurred in CTA-guided surgery [5 (10.0%) occurred in group H3DR to CTA, P<0.01]. Moreover, in the CTA-guided group, the separation of renal hilum was avoided in 14 of 19 (73.7%) cases, whereas in the H3DR-guided group, it was avoided in 60 of 63 (95.3%) cases.

Conclusions

For patients undergoing RALPN, H3DR-guided surgery compared with standard CTA-guided surgery has higher accuracy and feasibility in controlling arterial branches supplying the tumor and intraoperative surgical navigation. Additionally, it reduces the ischemic lesion area and simplifies vascular isolation steps, thus decreasing procedural difficulty.

Three-dimensional Model-assisted Minimally Invasive Partial Nephrectomy: A Systematic Review with Meta-analysis of Comparative Studies

CONTEXT

Use of three-dimensional (3D) guidance for nephron-sparing surgery (NSS) has increased in popularity, especially for laparoscopic and robotic approaches. Different 3D visualization modalities have been developed as promising new tools for surgical planning and intraoperative navigation.

OBJECTIVES

To summarize and evaluate the impact of 3D models on minimally invasive NSS in terms of perioperative, functional, and oncological outcomes.

EVIDENCE ACQUISITION

A systematic literature search was conducted in December 2021 using the Medline (PubMed), Embase (Ovid), Scopus, and Web of Science databases. The protocol was registered on PROSPERO (CRD42022300948). The search strategy used the PICOS (Population, Intervention, Comparison, Outcome, Study design) criteria and article selection was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias and the quality of the articles included were assessed. A dedicated data extraction form was used to collect the data of interest. Meta-analysis was performed using the Mantel-Haenszel method for binary outcomes, with results summarized as the odds ratio (OR), and the inverse variance method for continuous data, with results reported as the mean difference (MD). All effect estimates are reported with the 95% confidence interval (CI) and p ≤ 0.05 was considered statistically significant. All analyses were performed using R software and the meta package.

EVIDENCE SYNTHESIS

The initial electronic search identified 450 papers, of which 17 met the inclusion criteria and were included in the analysis. Use of 3D technology led to a significant reduction in the global ischemia rate (OR 0.22, 95% CI 0.07-0.76; p = 0.02) and facilitated more frequent enucleation (OR 2.54, 95% CI 1.36-4.74; p < 0.01) and less frequent opening of the collecting system (OR 0.36, 95% CI 0.15-0.89; p = 0.03) and was associated with less blood loss (MD 23.1 ml, 95% CI 31.8-14.4; p < 0.01). 3D guidance for NSS was associated with a significant reduction in the transfusion rate (OR 0.20, 95% CI 0.07-0.56; p < 0.01). There were no significant differences in rates of conversion to radical nephrectomy, minor and major complications, change in glomerular filtration rate, or surgical margins (all p > 0.05).

CONCLUSIONS

3D guidance for NSS is associated with lower rates of detriment and surgical injury to the kidney. Specifically, a lower amount of nontumor renal parenchyma is exposed to ischemia or sacrificed during resection, and opening of the collecting system is less frequent. However, use of 3D technology does not lead to significant improvements in oncological or functional outcomes.

PATIENT SUMMARY

We reviewed the use of three-dimensional tools for minimally invasive surgery for partial removal of the kidney in patients with kidney cancer. The evidence suggests that these tools have benefits during surgery, but do not lead to significant improvements in cancer control or functional outcomes for patients.

Systematic Review of Comparative Studies of 3D Models for Preoperative Planning in Minimally Invasive Partial Nephrectomy

Background: The employment of 3-dimensional (3D) virtual models of the organs and tumors, obtained from conventional 2-dimensional (2D) imaging (i.e. computed tomography scan and magnetic resonance imaging) have already demonstrated an outstanding potential in urology, especially in renal surgery. Objectives: The aim of this systematic review is to provide an updated focus on the results obtained from the preoperative employment of 3D virtual imaging reconstructions in nephron sparing oncological surgery. Methods: A systematic literature search was conducted in April 2022 using Medline (via PubMed), Embase (via Ovid), Scopus, and Web of Science. The search strategy used PICO criteria and article selection was conducted in accordance with the PRISMA guidelines. The risk of bias and the quality of the articles included were assessed. A dedicated data extraction form was used to collect the data of interest. Results: The initial electronic search identified 471 papers, of which 13 ultimately met the inclusion criteria and were included in the review. 11 studies reported outcomes of virtual models, 2 studies focused on printed 3D models. In these studies, the application of 3D models for preoperative planning has been reported to increase the selective clamping rate and reducing the opening of collecting system, blood loss and loss of renal function. Conclusions: 3D virtual models seem to provide some surgical benefits for preoperative planning especially for complex renal masses. In the next future the continuous evolution of this technology may further increase its field of application and its potential clinical benefit.

Personalized Surgical Planning for Soft Tissue Sarcoma of the Popliteal Fossa with a Novel 3D Imaging Technique

Objective

Soft tissue sarcomas (STSs) arising from the popliteal fossa pose surgical challenges due to their proximity to critical neurovascular structures. This study aimed to investigate whether a novel 3D imaging technique highlighting these key anatomical structures could facilitate preoperative planning and improve surgical outcomes in STS.

Methods

This was a prospective, observational, pilot study. Between November 2019 and December 2020, 27 patients with STS of the popliteal fossa undergoing limb‐sparing procedures were enrolled and assigned to either a control or intervention group. Control patients underwent traditional preoperative planning with separate computed tomography angiography, magnetic resonance imaging, and magnetic resonance hydrography. In the intervention group, 3D images were generated from these images, the tumor and skeletomuscular and neurovascular structures were revealed in three dimensions, and this was visualized on the surgeon's smartphone or computer. Primary endpoints were surgical margins and complications. Secondary endpoints included operative time, blood loss, serum C‐reactive protein and interleukin‐6, length of in‐hospital stay, and limb function. Comparisons between groups were made using independent‐sample t‐tests for continuous data and the Mann–Whitney U and Fisher's exact tests for categorical data.

Results

There was a lower but not significantly different inadvertent positive margin rate (1/15 vs. 3/12, P = 0.294), significantly shorter hospital stay (P = 0.049), and less numbers ≥75th percentile of operative time (P = 0.037) and blood loss (P = 0.024) in the intervention group. Differences in surgical complications, operative time, blood loss, C‐reactive protein and interleukin‐6 levels on the second postoperative day, and limb functional scores were statistically insignificant.

Conclusions

The novel 3D imaging technique facilitates complex preoperative planning and limb‐salvage surgical procedures for patients with STS of the popliteal fossa, and this may affect how surgical planning is performed in the future.

Clinical experience of using virtual 3D modelling for pre and intraoperative guidance during robotic-assisted partial nephrectomy

Objective:

Surgical planning for robotic-assisted partial nephrectomy is widely performed using two-dimensional computed tomography images. It is unclear to what extent two-dimensional images fully simulate surgical anatomy and case complexity. To overcome these limitations, software has been developed to reconstruct three-dimensional models from computed tomography data. We present the results of a feasibility study, to explore the role and practicality of virtual three-dimensional modelling (by Innersight Labs) in the context of surgical utility for preoperative and intraoperative use, as well as improving patient involvement.

Methods:

A prospective study was conducted on patients undergoing robotic-assisted partial nephrectomy at our high volume kidney cancer centre. Approval from a research ethics committee was obtained. Patient demographics and tumour characteristics were collected. Surgical outcome measures were recorded. The value of the three-dimensional model to the surgeon and patient was assessed using a survey. The prospective cohort was compared against a retrospective cohort and cases were individually matched using RENAL (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, location relative to polar lines) scores.

Results:

This study included 22 patients. Three-dimensional modelling was found to be safe for this prospective cohort and resulted in good surgical outcome measures. The mean (standard deviation) console time was 158.6 (35) min and warm ischaemia time was 17.3 (6.3) min. The median (interquartile range) estimated blood loss was 125 (50–237.5) ml. Two procedures were converted to radical nephrectomy due to the risk of positive margins during resection. The median (interquartile range) length of stay was 2 (2–3) days. No postoperative complications were noted and all patients had negative surgical margins. Patients reported improved understanding of their procedure using the three-dimensional model.

Conclusion:

This study shows the potential benefit of three-dimensional modelling technology with positive uptake from surgeons and patients. Benefits are improved perception of vascular anatomy and resection approach, and procedure understanding by patients. A randomised controlled trial is needed to evaluate the technology further.

Level of evidence:

2b

Preoperative Planning Using Three-Dimensional Multimodality Imaging for Soft Tissue Sarcoma of the Axilla: A Pilot Study

Axillary soft tissue sarcoma (STS) is challenging due to its proximity to vital neurovascular bundles. We conducted a prospective observational pilot study to explore whether 3D multimodality imaging (3DMMI) can improve preoperative planning for and surgical outcomes of patients with axillary STS. Twenty-one patients with STS (diameter > 5 cm) of the axilla were allocated, at their discretion, to either a control group undergoing traditional preoperative planning with separate computed tomography angiography, magnetic resonance imaging, and magnetic resonance neurography, or an intervention group where 3DMMI, digitally created based on these images, revealed the tumour and adjacent skeletomuscular and neurovascular structures in three dimensions. Primary outcome measures were surgical margins and surgical complications. Secondary outcomes included operative time, blood loss, serum C-reactive protein and interleukin-6, length of hospital stay, and limb function. The 3DMMI group had a lower, although not significantly different, inadvertent positive margin rate (1/12 vs. 3/9, p = 0.272), a significantly shorter operative time (p = 0.048), reduced blood loss (p = 0.038), and reduced length of hospital stay (p = 0.046). This endorses larger trials to improve complex surgical procedures and study how preoperative planning could be performed in the future.

New imaging technologies for robotic kidney cancer surgery

Objective

Kidney cancers account for approximately 2% of all newly diagnosed cancer in 2020. Among the primary treatment options for kidney cancer, urologist may choose between radical or partial nephrectomy, or ablative therapies. Nowadays, robotic-assisted partial nephrectomy (RAPN) for the management of renal cancers has gained popularity, up to being considered the gold standard. However, RAPN is a challenging procedure with a steep learning curve.

Methods

In this narrative review, different imaging technologies used to guide and aid RAPN are discussed.

Results

Three-dimensional visualization technology has been extensively discussed in RAPN, showing its value in enhancing robotic-surgery training, patient counseling, surgical planning, and intraoperative guidance. Intraoperative imaging technologies such as intracorporeal ultrasound, near-infrared fluorescent imaging, and intraoperative pathological examination can also be used to improve the outcomes following RAPN. Finally, artificial intelligence may play a role in the field of RAPN soon.

Conclusion

RAPN is a complex surgery; however, many imaging technologies may play an important role in facilitating it.

Role and Utility of Mixed Reality Technology in Laparoscopic Partial Nephrectomy: Outcomes of a Prospective RCT Using an Indigenously Developed Software

Objective

To develop a software for mixed reality (MR) anatomical model creation and study its intraoperative clinical utility to facilitate laparoscopic partial nephrectomy.

Materials and Methods

After institutional review board approval, 47 patients were prospectively randomized for LPN into two groups: the control group (24 patients) underwent operation with an intraoperative ultrasound (US) control and the experimental group (23 patients) with smart glasses HoloLens 2 (Microsoft, Seattle, WA, USA). Our team has developed an open-source software package called “HLOIA,” utilization of which allowed to create and use during surgery the MR anatomical model of the kidney with its vascular pedicle and tumor. The study period extended from June 2020 to February 2021 where demographic, perioperative, and pathological data were collected for all qualifying patients. The objective was to assess the utility of a MR model during LPN and through a 5-point Likert scale questionnaire, completed by the surgeon, immediately after LPN. Patient characteristics were tested using the chi-square test for categorical variables and Student's t-test or Mann–Whitney test for continuous variables.

Results

Comparison of the variables between the groups revealed statistically significant differences only in the following parameters: the time for renal pedicle exposure and the time from the renal pedicle to the detection of tumor localization (p < 0.001), which were in favor of the experimental group. The surgeon's impression of the utility of the MR model by the proposed questionnaire demonstrated high scores in all statements.

Conclusions

Developed open-source software “HLOIA” allowed to create the mixed reality anatomical model by operating urologist which is when used with smart glasses has shown improvement in terms of time for renal pedicle exposure and time for renal tumor identification without compromising safety.

Combination of holographic imaging with robotic partial nephrectomy for renal hilar tumor treatment

OBJECTIVES

To evaluate the clinical value of the holographic imaging technology in combination with robotic-assisted partial nephrectomy (RAPN) for renal hilar tumor treatment.

PATIENTS AND METHODS

From Dec. 2018 to Dec. 2021, patients diagnosed with renal hilar tumor were included in this retrospective study. Before the surgery, the engineers established the holographic image models based on the enhanced CT data. The models were used in patient consultation, pre-surgery planning and surgery simulation. During the RAPN, the navigation was achieved by real-time overlapping of the holographic images on the robotic surgery endoscopic views. The navigation technique helped the surgeon to identify the important anatomic structures such as tumor, renal vein, renal artery, and pelvis.

RESULTS

There were total of eight patients with renal hilar tumor who underwent RAPN combined with holographic imaging technique. The mean age was 57.3 years, the median ASA score was 2. The mean tumor size was 42.4 mm and the median RENAL Nephrometry score was 9.5. The clinical stages were cT1a (37.5%) and cT1b (62.5%). All the procedures were performed uneventfully by one surgeon. The mean operative time was 144.3 min, and the mean warm ischemia time was 27.9 min. The mean estimated blood loss was 86.3 ml. There was no conversion to open surgery or radical nephrectomy. There were no Clavien-Dindo ≥ 3 perioperative complications.

CONCLUSIONS

Using the holographic imaging technique, the pre-surgery planning, simulation of renal arterial clamp and excision of the tumor, and intraoperative navigation were feasible and helpful in facilitating RAPN.

Integration of Three-Dimensional Liver Models in a Multimodal Image-Guided Robotic Liver Surgery Cockpit

Background: Robotic liver surgery represents the most recent evolution in the field of minimally-invasive liver surgery. For planning and guidance of liver resections, surgeons currently rely on preoperative 2-dimensional (2D) CT and/or MR imaging and intraoperative ultrasonography. Translating 2D images into digital 3-dimensional (3D) models may improve both preoperative planning and surgical guidance. The da Vinci^® robotic surgical system is a platform suitable for the integration of multiple imaging modalities into one single view. In this study, we describe multimodal imaging options and introduce the Robotic Liver Surgery Cockpit; Methods: in-house developed software was used and validated for segmentation and registration to create a virtual reality 3D model of the liver based on preoperative imaging. The accuracy of the 3D models in the clinical setting was objectively assessed in 15 patients by measuring tumor diameters and subjectively with a postoperative conducted questionnaire; Results: Implementation and applicability of the 3D model in the surgical cockpit was feasible in all patients and the quality of the 3D reconstructions was high in 14 (93%) of cases. Tumor diameters measured on CT and/or MR imaging were comparable to automated measurements using the segmentation software and 3D models; Conclusions: the 3D model was successfully incorporated in the robotic surgery console as part of a multimodality imaging platform and aided the surgeon in planning and guidance of the resection. Future studies should focus on further automation of 3D rendering and progress into augmented reality.

The impact of three-dimensional reconstruction and standardised CT interpretation (AMIGO) on the anatomical understanding of mesenteric vascular anatomy for planning complete mesocolic excision surgery: A randomised crossover study

BACKGROUND

Preoperative planning is a crucial aspect of safe complete mesocolic excision (CME) surgery. 3D models derived from imaging may help improve anatomical understanding of the complex vascular anatomy. Here, we assessed the effect of 3D models on surgeons' anatomical understanding in comparison to a systematic approach for CT scan interpretation (AMIGO).

METHOD

Fifteen cases were included in the study. Two GI radiology consultants reviewed each scan to ascertain the vascular anatomy. Virtual 3D models were produced and displayed on a web-based platform (https://skfb.ly/6OZUZ). A total of 13 surgical trainees were recruited. Candidates were assessed after baseline anatomical training and subsequently using the AMIGO method and 3D models. Five cases were randomly allocated in each round of testing for each participant. The primary outcome measure was an objective vascular anatomy knowledge score. The secondary outcome measure was subjective feedback from participants.

RESULTS

Both 3D and AMIGO significantly improved anatomical understanding in comparison to baseline testing. However, 3D was superior to AMIGO (3D [n = 65; median score 8/14] vs. AMIGO [n = 65; median score 6/14; p < 0.0001]. For 13/15 patient cases examined, 3D was superior to the AMIGO method. Eleven participants demonstrated better anatomical understanding using 3D models versus AMIGO. Ten participants preferred 3D models in comparison to standard CT imaging.

CONCLUSIONS

3D models improve anatomical understanding of mesenteric vascular anatomy in a group of colorectal surgical trainees in comparison to a formal CT interpretation method. 3D models may be a useful planning adjunct to 2D imaging for CME surgery.

The current and possible future role of 3D modelling within oesophagogastric surgery: a scoping review

BACKGROUND

3D reconstruction technology could revolutionise medicine. Within surgery, 3D reconstruction has a growing role in operative planning and procedures, surgical education and training as well as patient engagement. Whilst virtual and 3D printed models are already used in many surgical specialities, oesophagogastric surgery has been slow in their adoption. Therefore, the authors undertook a scoping review to clarify the current and future roles of 3D modelling in oesophagogastric surgery, highlighting gaps in the literature and implications for future research.

METHODS

A scoping review protocol was developed using a comprehensive search strategy based on internationally accepted guidelines and tailored for key databases (MEDLINE, Embase, Elsevier Scopus and ISI Web of Science). This is available through the Open Science Framework (osf.io/ta789) and was published in a peer-reviewed journal. Included studies underwent screening and full text review before inclusion. A thematic analysis was performed using pre-determined overarching themes: (i) surgical training and education, (ii) patient education and engagement, and (iii) operative planning and surgical practice. Where applicable, subthemes were generated.

RESULTS

A total of 56 papers were included. Most research was low-grade with 88% (n = 49) of publications at or below level III evidence. No randomised control trials or systematic reviews were found. Most literature (86%, n = 48) explored 3D reconstruction within operative planning. These were divided into subthemes of pre-operative (77%, n = 43) and intra-operative guidance (9%, n = 5). Few papers reported on surgical training and education (14%, n = 8), and were evenly subcategorised into virtual reality simulation (7%, n = 4) and anatomical teaching (7%, n = 4). No studies utilising 3D modelling for patient engagement and education were found.

CONCLUSION

The use of 3D reconstruction is in its infancy in oesophagogastric surgery. The quality of evidence is low and key themes, such as patient engagement and education, remain unexplored. Without high quality research evaluating the application and benefits of 3D modelling, oesophagogastric surgery may be left behind.

Robotic partial nephrectomy in 3D virtual reconstructions era: is the paradigm changed?

CONTEXT

The development of a tailored, patient-specific medical and surgical approach is becoming object of intense research. In kidney oncologic surgery, where a clear understanding of case-specific surgical anatomy is considered a key point to optimize the perioperative outcomes, such philosophy gained increasing importance. Recently, important advances in 3D virtual modeling technologies have fueled the interest for their application in the field of robotic minimally invasive surgery for kidney tumors.

OBJECTIVE

To provide a synthesis of current applications of 3D virtual models for robot-assisted partial nephrectomy.

EVIDENCE ACQUISITION

Medline, PubMed, the Cochrane Database, and Embase were screened for Literature regarding the use of 3D virtual models for robot-assisted partial nephrectomy (RAPN).

EVIDENCE SYNTHESIS

The use of 3D virtual models for RAPN has been tested in different settings, including surgical indication and planning, intraoperative guidance, and training. Currently, several studies are available on the application of this technology for surgical planning, demonstrating impact on clinical outcomes such as renal function recovery, whilst experiences concerning their intraoperative application for navigation are still experimental. One of the latest innovations in this field is represented by the development of dedicated softwares able to automatically overlap the 3D virtual models to the real anatomy, to perform augmented reality procedures.

CONCLUSIONS

The available Literature suggests a potentially crucial role of 3D virtual reconstructions during RAPN. Encouraging results concerning surgical planning and indication, intraoperative navigation, and surgical training are available. In the future, artificial intelligence may represent the key to further improve the 3D virtual modeling technology during RAPN.

Improving accuracy, reliability, and efficiency of the RENAL nephrometry score with 3D reconstructed virtual imaging

OBJECTIVE

To clarify the diagnostic performance of the three-dimensional reconstructed virtual image (3D-RVI) in evaluating RENAL nephrometry score (RENAL-NS).

METHODS

This study included 130 patients who underwent preoperative contrast-enhanced computed tomography (CECT) followed by partial nephrectomy for renal tumors suggestive of renal cell carcinoma. RENAL-NS was calculated prior to the surgery, and tumor resection was performed referring to the score. We retrospectively reviewed preoperative CECT images. We calculated the inter-observer variability of RENAL-NS using 3D-RVI versus two-dimensional (2D) imaging and compared the ability of RENAL-NS using 3D-RVI versus 2D imaging to predict the risk of opening of the urinary collecting system. We also compared the two modalities for the time required to evaluate RENAL-NS.

RESULTS

RENAL-NS evaluated using 3D-RVI showed a higher inter-observer agreement compared to 2D-imaging (r_s = 0.85 vs. r_s = 0.65). The "nearness to sinus" score was more strongly associated with the opening of the urinary collecting system when evaluated using 3D-RVI than 2D-imaging (AUC = 0.71 vs AUC = 0.57, p = 0.016). RENAL-NS using 2D-imaging required a significantly longer time compared to 3D-RVI (p = 0.036).

CONCLUSIONS

Using 3D-RVI improves the accuracy, reliability and efficiency of RENAL-NS evaluation in preoperative assessment and can play an important role in preoperative assessment and intraoperative navigation.

Virtual Reality in the Preoperative Planning of Adult Aortic Surgery: A Feasibility Study

Background: Complex aortic anatomy needs careful preoperative planning in which a patient-tailored approach with novel immersive techniques could serve as a valuable addition to current preoperative imaging. This pilot study aimed to investigate the technical feasibility of virtual reality (VR) as an additional imaging tool for preoperative planning in ascending aortic surgery. Methods: Ten cardiothoracic surgeons were presented with six patients who had each undergone a recent repair of the ascending aorta. Two-dimensional computed tomography images of each patient were assessed prior to the VR session. After three-dimensional (3D) VR rendering and 3D segmentation of the ascending aorta and aortic arch, the reconstructions were analyzed by each surgeon in VR via a head-mounted display. Each cardiothoracic surgeon completed a questionnaire after each planning procedure. The results of their assessments were compared to the performed operations. The primary endpoint of the present study was a change of surgical approach from open to clamped distal anastomosis, and vice versa. Results: Compared with conventional imaging, 80% of surgeons found that VR prepared them better for surgery. In 33% of cases (two out of six), the preoperative decision was adjusted due to the 3D VR-based evaluation of the anatomy. Surgeons rated CardioVR usefulness, user-friendliness, and satisfaction with median scores of 3.8 (IQR: 3.5–4.1), 4.2 (IQR: 3.8–4.6,) and 4.1 (IQR: 3.8–4.7) on a five-point Likert scale, respectively. Conclusions: Three-dimensional VR imaging was associated with improved anatomical understanding among surgeons and could be helpful in the future preoperative planning of ascending aortic surgery.

Methods and Applications of 3D Patient-Specific Virtual Reconstructions in Surgery

3D modelling has been highlighted as one of the key digital technologies likely to impact surgical practice in the next decade. 3D virtual models are reconstructed using traditional 2D imaging data through either direct volume or indirect surface rendering. One of the principal benefits of 3D visualisation in surgery relates to improved anatomical understanding-particularly in cases involving highly variable complex structures or where precision is required.Workflows begin with imaging segmentation which is a key step in 3D reconstruction and is defined as the process of identifying and delineating structures of interest. Fully automated segmentation will be essential if 3D visualisation is to be feasibly incorporated into routine clinical workflows; however, most algorithmic solutions remain incomplete. 3D models must undergo a range of processing steps prior to visualisation, which typically include smoothing, decimation and colourization. Models used for illustrative purposes may undergo more advanced processing such as UV unwrapping, retopology and PBR texture mapping.Clinical applications are wide ranging and vary significantly between specialities. Beyond pure anatomical visualisation, 3D modelling offers new methods of interacting with imaging data; enabling patient-specific simulations/rehearsal, Computer-Aided Design (CAD) of custom implants/cutting guides and serves as the substrate for augmented reality (AR) enhanced navigation.3D may enable faster, safer surgery with reduced errors and complications, ultimately resulting in improved patient outcomes. However, the relative effectiveness of 3D visualisation remains poorly understood. Future research is needed to not only define the ideal application, specific user and optimal interface/platform for interacting with models but also identify means by which we can systematically evaluate the efficacy of 3D modelling in surgery.

A System for Real-Time, Online Mixed-Reality Visualization of Cardiac Magnetic Resonance Images

Image-guided cardiovascular interventions are rapidly evolving procedures that necessitate imaging systems capable of rapid data acquisition and low-latency image reconstruction and visualization. Compared to alternative modalities, Magnetic Resonance Imaging (MRI) is attractive for guidance in complex interventional settings thanks to excellent soft tissue contrast and large fields-of-view without exposure to ionizing radiation. However, most clinically deployed MRI sequences and visualization pipelines exhibit poor latency characteristics, and spatial integration of complex anatomy and device orientation can be challenging on conventional 2D displays. This work demonstrates a proof-of-concept system linking real-time cardiac MR image acquisition, online low-latency reconstruction, and a stereoscopic display to support further development in real-time MR-guided intervention. Data are acquired using an undersampled, radial trajectory and reconstructed via parallelized through-time radial generalized autocalibrating partially parallel acquisition (GRAPPA) implemented on graphics processing units. Images are rendered for display in a stereoscopic mixed-reality head-mounted display. The system is successfully tested by imaging standard cardiac views in healthy volunteers. Datasets comprised of one slice (46 ms), two slices (92 ms), and three slices (138 ms) are collected, with the acquisition time of each listed in parentheses. Images are displayed with latencies of 42 ms/frame or less for all three conditions. Volumetric data are acquired at one volume per heartbeat with acquisition times of 467 ms and 588 ms when 8 and 12 partitions are acquired, respectively. Volumes are displayed with a latency of 286 ms or less. The faster-than-acquisition latencies for both planar and volumetric display enable real-time 3D visualization of the heart.

Virtual reality of three-dimensional surgical field for surgical planning and intraoperative management

PURPOSE

To investigate the impact of virtual reality (VR) technologies on urological surgeries, specifically in the management of prostate cancer and renal cancer.

METHODS

A non-systematic review of the literature was performed. Medline, Pubmed, and the Cochrane Database were screened for studies regarding the use of VR technologies in the management of prostate and renal cancer.

RESULTS

In the management of prostate cancer, VR technologies have been increasingly applied for diagnosis with magnetic resonance imaging/ultrasound fusion biopsy, surgical training using a simulator, surgical navigation in robot-assisted radical prostatectomy, and targeted focal therapy. In partial nephrectomy, surgical simulation and intra-surgical guidance with three-dimensional VR have been used for better understanding of the hilar vascular information, tumor location, and positional relationships of the tumor-feeding vessel and pyelocaliceal system.

CONCLUSIONS

VR contributes to the education, training, and simulation of surgical procedures as well as helping the surgeons to tailor surgical planning on each patient. Further prospective studies are needed to assess the beneficial impacts of this technology for both the physician and patient by objective parameters.

3D Virtual Reality Imaging of Major Aortopulmonary Collateral Arteries: A Novel Diagnostic Modality

BACKGROUND

Major aortopulmonary collateral arteries (MAPCAs), as seen in patients with pulmonary atresia, are arteries that supply blood from the aorta to the lungs and often require surgical intervention. To achieve complete repair in the least number of interventions, optimal imaging of the pulmonary arterial anatomy and MAPCAs is critical. 3D virtual reality (3D-VR) is a promising and upcoming new technology that could potentially ameliorate current imaging shortcomings.

METHODS

A retrospective, proof-of-concept study was performed of all operated patients with pulmonary atresia and MAPCAs at our center between 2010 and 2020 with a preoperative computed tomography (CT) scan. CT images were reviewed by two congenital cardiac surgeons in 3D-VR to determine additional value of VR for MAPCA imaging compared to conventional CT and for preoperative planning of MAPCA repair.

RESULTS

3D-VR visualizations were reconstructed from CT scans of seven newborns where the enhanced topographic anatomy resulted in improved visualization of MAPCA. In addition, surgical planning was improved since new observations or different preoperative plans were apparent in 4 out of 7 cases. After the initial setup, VR software and hardware was reported to be easy and intuitive to use.

CONCLUSIONS

This study showed technical feasibility of 3D-VR reconstruction of children with immersive visualization of topographic anatomy in an easy-to-use format leading to an improved surgical planning of MAPCA surgery. Future prospective studies are required to investigate the clinical benefits in larger populations.

Virtual reality for 3D histology: multi-scale visualization of organs with interactive feature exploration

Background

Virtual reality (VR) enables data visualization in an immersive and engaging manner, and it can be used for creating ways to explore scientific data. Here, we use VR for visualization of 3D histology data, creating a novel interface for digital pathology to aid cancer research.

Methods

Our contribution includes 3D modeling of a whole organ and embedded objects of interest, fusing the models with associated quantitative features and full resolution serial section patches, and implementing the virtual reality application. Our VR application is multi-scale in nature, covering two object levels representing different ranges of detail, namely organ level and sub-organ level. In addition, the application includes several data layers, including the measured histology image layer and multiple representations of quantitative features computed from the histology.

Results

In our interactive VR application, the user can set visualization properties, select different samples and features, and interact with various objects, which is not possible in the traditional 2D-image view used in digital pathology. In this work, we used whole mouse prostates (organ level) with prostate cancer tumors (sub-organ objects of interest) as example cases, and included quantitative histological features relevant for tumor biology in the VR model.

Conclusions

Our application enables a novel way for exploration of high-resolution, multidimensional data for biomedical research purposes, and can also be used in teaching and researcher training. Due to automated processing of the histology data, our application can be easily adopted to visualize other organs and pathologies from various origins.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08542-9.

Test clamp procedure in robot-assisted partial nephrectomy: is it a safe procedure?

We performed test clamp procedure in robot-assisted partial nephrectomy (RAPN) to prevent massive bleeding during tumor resection and to omit dissection of non-feeding arteries around the tumor. We subsequently analyzed the safety and usefulness of the procedure. The Test clamp procedure was performed for 1 to 3 min during renal artery test ischemia prior to the actual ischemia and tumor resection. We confirmed the disappearance of blood flow around the renal tumor using color Doppler ultrasonography. If arterial blood flow around the tumor remained, we surveyed the site for other arteries that needed to be clamped and repeated the test clamp procedure until renal blood flow around the tumor disappeared. We retrospectively analyzed consecutive RAPN cases performed from July 2016 to March 2020 at our institutions and reviewed medical records. The clinical data of the RAPN cases were statistically analyzed. Sixty-four RAPN cases underwent the test clamp procedure, which was categorized as the TEST group. Test clamping was performed safely without any clamping-related complications in all cases. Eleven cases (17%) underwent partial ischemia, which was a significantly higher number than that in the control group. Massive bleeding during tumor resection was more frequent in the control group. Postoperative deterioration of estimated glomerular filtration rate did not differ significantly between both groups. Although further investigation was still necessary, our findings indicate that the test clamp procedure may be a safe and secure procedure to perform in RAPN for both patients and surgeons.

Patient-specific virtual reality technology for complex neurosurgical cases: illustrative cases

BACKGROUND

Virtual reality (VR) offers an interactive environment for visualizing the intimate three-dimensional (3D) relationship between a patient’s pathology and surrounding anatomy. The authors present a model for using personalized VR technology, applied across the neurosurgical treatment continuum from the initial consultation to preoperative surgical planning, then to intraoperative navigation, and finally to postoperative visits, for various tumor and vascular pathologies.

OBSERVATIONS

Five adult patients undergoing procedures for spinal cord cavernoma, clinoidal meningioma, anaplastic oligodendroglioma, giant aneurysm, and arteriovenous malformation were included. For each case, 360-degree VR (360°VR) environments developed using Surgical Theater were used for patient consultation, preoperative planning, and/or intraoperative 3D navigation. The custom 360°VR model was rendered from the patient’s preoperative imaging. For two cases, the plan changed after reviewing the patient’s 360°VR model from one based on conventional Digital Imaging and Communications in Medicine imaging.

LESSONS

Live 360° visualization with Surgical Theater in conjunction with surgical navigation helped validate the decisions made intraoperatively. The 360°VR models provided visualization to better understand the lesion’s 3D anatomy, as well as to plan and execute the safest patient-specific approach, rather than a less detailed, more standardized one. In all cases, preoperative planning using the patient’s 360°VR model had a significant impact on the surgical approach.