Editor's Note: As the concept of precision surgery continues to advance, partial nephrectomy (PN) has become the gold standard for the treatment of early-stage renal cancer. However, accurately identifying anatomy intraoperatively, shortening warm ischemia time, and preserving renal function remain major challenges for urologists, particularly when treating complex hilar and endophytic renal tumors. Recently, at the CACA GU meeting, Professor Lei Wang, Chief Physician in the Department of Urology at Peking University Shougang Hospital, delivered an in-depth presentation on the applications of holographic imaging in partial nephrectomy. Drawing on years of clinical experience and research findings from his team, Professor Wang outlined the technological evolution from three-dimensional reconstruction to medical holographic imaging and demonstrated the potential advantages of this technology in supporting complex surgical decision-making and improving the likelihood of achieving the “Trifecta” outcome.Medical Holographic Imaging: A Digital Revolution From “Viewing Flat Images” to “Three-Dimensional Interaction”
The kidney has a complex anatomical structure, and the renal hilar region exhibits considerable variation in vascular branching. These characteristics pose significant challenges for surgical planning and intraoperative localization during partial nephrectomy (PN). Conventional imaging modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), typically present anatomical information in two-dimensional slices. Although these images help surgeons understand basic anatomical structures, they do not intuitively convey spatial relationships.
Preoperative three-dimensional reconstruction (3DR) creates spatial models that can improve surgeons’ understanding of anatomical relationships. However, different software systems still vary considerably in their interactive capabilities, organ segmentation accuracy, and ability to provide real-time intraoperative mapping. The standardization and convenience of clinical implementation therefore require further improvement.
Holographic imaging (HI) integrates patient imaging data to generate digital models that can be zoomed, separated into individual structures, rotated, rendered transparent, and quantitatively measured. This provides surgeons with a more flexible and intuitive means of examining anatomy. It should be noted that the HI discussed in this presentation primarily refers to interactive, high-resolution three-dimensional visualization and navigation systems, rather than conventional holographic photography in the physical-optics sense.
HI can also be combined with mixed reality (MR) technology to superimpose virtual anatomical models onto the actual surgical field. This provides more intuitive and comprehensive spatial information to support preoperative discussions, intraoperative reference, and real-time navigation.
Integrating Virtual and Real Anatomy: Intraoperative Decision Support With Mixed Reality
In surgical practice, HI can extend beyond preoperative image review to intraoperative navigation. The principle is to superimpose a patient-specific digital model onto the endoscopic surgical field, allowing surgeons to visualize the relative positions of the tumor, arterial and venous branches, collecting system, and ureter simultaneously. The system helps surgeons develop spatial awareness and plan surgical approaches, but it does not replace direct intraoperative observation, ultrasonography, or anatomical verification.
Surgeons can adjust the transparency of different tissue structures as the procedure progresses and use the model to measure distances and volumes. The presentation demonstrated the layered visualization capabilities of the RENXINMED system for the kidney, inferior vena cava, abdominal aorta, renal arteries and veins, ureter, and tumor.
Navigation accuracy may be affected by respiration, kidney displacement, tissue deformation, pneumoperitoneum, tissue traction, and registration errors. When the model does not match the actual surgical field, direct anatomical evidence and intraoperative ultrasound findings should take precedence.
Clinical Applications: Precision Resection and Functional Preservation in Complex Renal Tumors
The central value of holographic imaging-assisted surgery lies in its potential to facilitate the transition from traditional experience-based surgery to digitally enabled precision surgery. Professor Lei Wang discussed the practical applications of HI in partial nephrectomy through a series of clinical cases involving different tumor types.
HI can help identify variant blood vessels and assist surgeons in planning the surgical approach. At the meeting, Professor Wang presented a case involving an approximately 5-cm tumor in the lower pole of the right kidney, adjacent to the renal hilar vessels. The preoperative three-dimensional model indicated that the patient had two renal arteries supplying the kidney, providing a basis for selecting a transperitoneal approach. The surgical team used the model to plan the extent of vascular dissection and the resection margins in advance. Nevertheless, all vascular branches still required final confirmation during surgery.
For completely endophytic renal tumors, HI can use transparency rendering to clearly display the tumor’s projected location within the renal parenchyma. These findings can be cross-checked against intraoperative ultrasound to help surgeons determine the tumor entry and resection approach, including techniques such as the “unroofing” method. The key advantage of this technology is its intuitive presentation of anatomical structures; it cannot replace real-time ultrasound confirmation of tumor boundaries and depth.
In terms of blood flow control, segmental artery clamping (SAC) aims to interrupt blood flow only to the region supplied by the arteries feeding the tumor. HI can clearly display the arterial branches supplying the tumor, providing navigation support for selective clamping.
Another case presented during the meeting involved a 69-year-old woman with a tumor measuring approximately 3.5 × 2.0 cm at the posterior lip of the left renal hilum. The R.E.N.A.L. nephrometry score (RNS) was 7p. Based on the preoperative model, the surgical team planned a posterior approach for visualization and a strategy for segmental arterial clamping. The final decision to perform SAC still required a comprehensive assessment of vascular anatomy, the surgeon’s experience, and the anticipated benefits of ischemia reduction.
Tackling Complex Cases: Exploring HI in Challenging Renal Hilar Tumors and Rare Conditions
For complex renal hilar tumors, combining three-dimensional holographic imaging with a robotic surgical system can help visualize the tumor’s surrounding blood supply and vascular trajectories, thereby supporting the preoperative planning of vascular clamping sites. However, workflows and registration methods have not yet been standardized across institutions. In clinical practice, this technology must still be used in conjunction with intraoperative ultrasound and direct anatomical confirmation.
In one complex renal hilar tumor case presented during the session, HI-assisted vascular management and tumor resection were successfully performed. Warm ischemia time was approximately 25 minutes. Postoperative pathology confirmed clear cell renal cell carcinoma, WHO/ISUP grade 2, with negative surgical margins.
The presentation also explored potential applications of HI in the diagnosis and treatment of inferior vena cava (IVC) tumor thrombi and retroperitoneal tumors. The technology may help visualize the depth of tumor thrombus invasion, its relationship with the vascular wall, and deep tumor-feeding vessels. These individual cases demonstrate the feasibility of applying the technology, but they are insufficient to establish an independent effect on complication rates or long-term oncological outcomes.
Domestic and International Research: Evidence of Potential “Trifecta” Benefits From Retrospective Studies
Professor Wang systematically reviewed multiple case series and retrospective analyses from China and other countries. Existing evidence suggests that applying HI during laparoscopic or robot-assisted partial nephrectomy may help reduce unnecessary tissue injury, optimize vascular clamping strategies, and improve the consistency of surgical planning. However, most of these studies have nonrandomized designs, and their findings may be influenced by selection bias, differences in surgeons’ learning curves, and variations in clinical experience.
A comparative study by Porpiglia and colleagues evaluated HI-assisted robot-assisted PN against ultrasound-guided or conventional surgical approaches. Differences were observed between groups in outcomes including main renal artery clamping time, opening of the collecting system, complication rates, and postoperative estimated renal plasma flow (eRPF).
Pecoraro and colleagues focused on the composite “Trifecta” outcome, which comprises negative surgical margins, the absence of major complications, and effective preservation of renal function. Given the inconsistencies in outcome definitions and comparator methods across studies, it cannot currently be concluded that all observed differences are directly attributable to HI itself.
Overall, HI has demonstrated promising potential to improve understanding of complex anatomy and optimize perioperative planning. Professor Wang’s team is conducting a series of studies on automated holographic model construction and clinical applications, including projects under the 2024 Capital Health Development Scientific Research Special Project and the 2025 Shouyi Clinical Medical Scientist Hundred-Person Program. Further work will require rigorous evaluation using standardized measures of navigation accuracy, procedural safety, and patient outcomes.
Future Perspectives: Deeper Integration of Artificial Intelligence and Navigation Robotics
Discussing future directions, Professor Wang highlighted several key technological priorities, including artificial intelligence (AI) integration, automated segmentation, dynamic registration, and system integration.
AI can be used to automatically segment the kidney, tumor, blood vessels, and collecting system. This may shorten model construction time while improving the consistency and reproducibility of segmentation results. However, further validation is needed to establish the reliability of AI in compensating for respiratory motion and organ deformation, supporting the assessment of lesion characteristics, and providing error alerts. These safeguards are essential to ensure that automated outputs are not used directly for clinical decision-making without rigorous verification.
Professor Wang noted that automated registration and tracking are central to the development of navigation systems. Most current registration methods still rely on manual or semiautomated procedures. Future research should aim to update models in real time as the surgical field changes and further integrate electromagnetic or optical navigation technologies.
Before these systems can be adopted in routine clinical practice, their segmentation accuracy, navigation errors, failure-management pathways, and reproducibility must be systematically validated to ensure adequate robustness and safety.
At the hardware level, Professor Wang believes that augmented reality (AR) technology could be more deeply integrated with robotic systems, laparoscopic equipment, and electromagnetic or optical navigation systems, reducing the inconvenience of frequently switching between separate devices. He emphasized that the ultimate goal of technological development should not be to create increasingly impressive visual displays, but to enable safer resections, minimize damage to normal tissue, and deliver demonstrable benefits in renal function preservation.
Conclusion
Holographic imaging can transform complex patient-specific anatomy into interactive preoperative planning models and intraoperative reference tools. It may be particularly useful in procedures requiring a detailed understanding of spatial anatomy, including the resection of endophytic and renal hilar tumors and the implementation of segmental arterial clamping.
Navigation models cannot replace intraoperative ultrasound or direct anatomical confirmation. Organ deformation and registration errors remain important safety limitations. Current clinical evidence is primarily derived from case series and retrospective studies.
Future multicenter prospective studies are needed to standardize the definitions and assessment criteria for navigation accuracy, surgical complexity, complications, renal function, and Trifecta outcomes. These studies should establish whether HI genuinely improves patient-relevant outcomes and clarify the regulatory requirements and quality-control standards for AI-based automated segmentation and dynamic registration.
Professor Lei Wang
