Three-dimensional imaging reconstruction of the kidney's anatomy for a tailored minimal invasive partial nephrectomy: A pilot study

Cross-Species Insights into Autosomal Dominant Polycystic Kidney Disease: Provide an Alternative View on Research Advancement

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a prevalent hereditary disorder that affects the kidneys, characterized by the development of an excessive number of fluid-filled cysts of varying sizes in both kidneys. Along with the progression of ADPKD, these enlarged cysts displace normal kidney tissue, often accompanied by interstitial fibrosis and inflammation, and significantly impair renal function, leading to end-stage renal disease. Currently, the precise mechanisms underlying ADPKD remain elusive, and a definitive cure has yet to be discovered. This review delineates the epidemiology, pathological features, and clinical diagnostics of ADPKD or ADPKD-like disease across human populations, as well as companion animals and other domesticated species. A light has been shed on pivotal genes and biological pathways essential for preventing and managing ADPKD, which underscores the importance of cross-species research in addressing this complex condition. Treatment options are currently limited to Tolvaptan, dialysis, or surgical excision of large cysts. However, comparative studies of ADPKD across different species hold promise for unveiling novel insights and therapeutic strategies to combat this disease.

Are 3D Image Guidance Systems Ready for Use? A Comparative Analysis of 3D Image Guidance Implementations in Minimally Invasive Partial Nephrectomy

Introduction: Three-dimensional image-guided surgical (3D-IGS) systems for minimally invasive partial nephrectomy (MIPN) can potentially improve the efficiency and accuracy of intraoperative anatomical localization and tumor resection. This review seeks to analyze the current state of research regarding 3D-IGS, including the evaluation of clinical outcomes, system functionality, and qualitative insights regarding 3D-IGS's impact on surgical procedures. Methods: We have systematically reviewed the clinical literature pertaining to 3D-IGS deployed for MIPN. For inclusion, studies must produce a patient-specific 3D anatomical model from two-dimensional imaging. Data extracted from the studies include clinical results, registration (alignment of the 3D model to the surgical scene) method used, limitations, and data types reported. A subset of studies was qualitatively analyzed through an inductive coding approach to identify major themes and subthemes across the studies. Results: Twenty-five studies were included in the review. Eight (32%) studies reported clinical results that point to 3D-IGS improving multiple surgical outcomes. Manual registration was the most utilized (48%). Soft tissue deformation was the most cited limitation among the included studies. Many studies reported qualitative statements regarding surgeon accuracy improvement, but quantitative surgeon accuracy data were not reported. During the qualitative analysis, six major themes emerged across the nine applicable studies. They are as follows: 3D-IGS is necessary, 3D-IGS improved surgical outcomes, researcher/surgeon confidence in 3D-IGS system, enhanced surgeon ability/accuracy, anatomical explanation for qualitative assessment, and claims without data or reference to support. Conclusions: Currently, clinical outcomes are the main source of quantitative data available to point to 3D-IGS's efficacy. However, the literature qualitatively suggests the benefit of accurate 3D-IGS for robotic partial nephrectomy.

Comparing Perioperative Complications of Off-Clamp versus On-Clamp Partial Nephrectomy for Renal Cancer Using a Novel Energy Balancing Weights Method

Partial nephrectomy (PN) is the primary surgical method for renal tumor treatment, typically involving clamping the renal artery during tumor removal, leading to warm ischemia and potential renal function impairment. Off-clamp approaches have been explored to mitigate organ damage, yet few results have emerged about the possible effects on hemoglobin loss. Most evidence comes from retrospective studies using propensity score matching, known to be sensitive to PS model misspecification. The energy balancing weights (EBW) method offers an alternative method to address bias by focusing on balancing all the characteristics of covariate distribution. We aimed to compare on- vs. off-clamp techniques in PN using EB-weighted retrospective patient data. Out of 333 consecutive PNs (275/58 on/off-clamp ratio), the EBW method achieved balanced variables, notably tumor anatomy and staging. No significant differences were observed in the operative endpoints between on- and off-clamp techniques, although off-clamp PNs showed slight reductions in hemoglobin loss and renal function decline, albeit with slightly higher perioperative blood loss. Our findings support previous evidence, indicating comparable surgical outcomes between standard and off-clamp procedures, with the EBW method proving effective in balancing baseline variables in observational studies comparing interventions.

Automatic 3D Augmented-Reality Robot-Assisted Partial Nephrectomy Using Machine Learning: Our Pioneer Experience

The aim of "Precision Surgery" is to reduce the impact of surgeries on patients' global health. In this context, over the last years, the use of three-dimensional virtual models (3DVMs) of organs has allowed for intraoperative guidance, showing hidden anatomical targets, thus limiting healthy-tissue dissections and subsequent damage during an operation. In order to provide an automatic 3DVM overlapping in the surgical field, we developed and tested a new software, called "ikidney", based on convolutional neural networks (CNNs). From January 2022 to April 2023, patients affected by organ-confined renal masses amenable to RAPN were enrolled. A bioengineer, a software developer, and a surgeon collaborated to create hyper-accurate 3D models for automatic 3D AR-guided RAPN, using CNNs. For each patient, demographic and clinical data were collected. A total of 13 patients were included in the present study. The average anchoring time was 11 (6-13) s. Unintended 3D-model automatic co-registration temporary failures happened in a static setting in one patient, while this happened in one patient in a dynamic setting. There was one failure; in this single case, an ultrasound drop-in probe was used to detect the neoplasm, and the surgery was performed under ultrasound guidance instead of AR guidance. No major intraoperative nor postoperative complications (i.e., Clavien Dindo > 2) were recorded. The employment of AI has unveiled several new scenarios in clinical practice, thanks to its ability to perform specific tasks autonomously. We employed CNNs for an automatic 3DVM overlapping during RAPN, thus improving the accuracy of the superimposition process.

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

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

A systematic review of robot-assisted partial nephrectomy outcomes for advanced indications: Large tumors (cT2-T3), solitary kidney, completely endophytic, hilar, recurrent, and multiple renal tumors

Objective

Robot-assisted partial nephrectomy (RAPN) has become widely used for treatment of renal cell carcinoma and it is expanding in the field of complex renal masses. The aim of this systematic review was to analyze outcomes of RAPN for completely endophytic renal masses, large tumors (cT2-T3), renal cell carcinoma in solitary kidney, recurrent tumors, completely endophytic and hilar masses, and simultaneous and multiple tumors.

Methods

A comprehensive search in the PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials databases was performed in December 2022 for English language papers. The primary endpoint was to evaluate the role of RAPN in the setting of each category of complex renal masses considered. The secondary endpoint was to evaluate the surgical and functional outcomes.

Results

After screening 1250 records, 43 full-text manuscripts were selected, comprising over 8500 patients. Twelve and thirteen studies reported data for endophytic and hilar renal masses, respectively. Five and three studies reported outcomes for cT2-T3 and solitary kidney patients, respectively. Four studies focused on redo-RAPN for recurrent tumors. Two studies investigated simultaneous bilateral renal masses and five reports focused on multiple tumor excision in ipsilateral kidney.

Conclusion

Over the past decade, evidence supporting the use of RAPN for the most challenging nephron-sparing surgery indications has continuously grown. Although limitations remain including study design and lack of detailed long-term functional and oncological outcomes, the adoption of RAPN for the included advanced indications is associated with favorable surgical outcomes with good preservation of renal function without compromising the oncological result. Certainly, a higher likelihood of complication might be expected when facing extremely challenging cases. However, none of these indications should be considered per se an exclusion criterion for performing RAPN. Ultimately, a risk-adapted approach should be employed.

Implications of Tumor Surgery in Horseshoe Kidneys: A Comparative Study of Outcomes and Surgical Practices

OBJECTIVE

To contrast surgical outcomes of Horseshoe Kidney (HSK) patients with localized renal masses suspected of cancer with nonfused nonectopic kidney patients, emphasizing safe surgical practices for HSKs.

METHODS

The study examined solid tumors from the Mayo Clinic Nephrectomy registry between 1971 and 2021. Each HSK case was matched to three non-HSK patients based on various factors. The outcomes measured included complications within 30days of surgery, change in estimated glomerular filtration rate, and overall, cancer-specific, and metastasis-free survival rates.

RESULTS

Thirty of the 34 HSKs had malignant tumors compared with 90 of the 102 patients in the nonfused nonectopic referent cohort. Accessory isthmus arteries were present in 93% of HSK cases, with 43% exhibiting multiple arteries and 7% with 6 or more arteries. Estimated blood loss and surgery duration were significantly higher in HSKs (900 vs 300 mL, P = .004; 246 vs 163 minutes, P < .001, respectively). The HSK group demonstrated an overall complication rate of 26% (vs 17% in referents, P = .2) and a median change in estimated glomerular filtration rate at 3months of - 8.5 (vs -8.1 in referents, P = .8). At 5-year follow-up, survival rates for HSK patients were 72%, 91%, and 69% for overall, cancer-specific, and metastasis-free survival, respectively. The corresponding rates were 79%, 86%, and 77%, respectively, for matched referent patients (P > .05).

CONCLUSION

HSK tumor management is technically challenging with higher blood loss; however, the data demonstrate comparable outcomes for patients with HSK tumors, including complications and survival, to those without HSKs in experienced centers.

Every decade counts: a narrative review of functional recovery after partial nephrectomy

OBJECTIVE

To provide a narrative review of the major advances regarding ischaemia and functional recovery after partial nephrectomy (PN), along with the ongoing controversies.

METHODS

Key articles reflecting major advances regarding ischaemia and functional recovery after PN were identified. Special emphasis was placed on contributions that changed perspectives about surgical management. Priority was also placed on randomized trials of off-clamp vs on-clamp cohorts.

RESULTS

A decade ago, 'Every minute counts' was published, showing strong correlations between duration of ischaemia and development of acute kidney injury (AKI) and chronic kidney disease after clamped PN. This reinforced perspectives that ischaemia was the main modifiable factor that could be addressed to improve functional outcomes and helped spur efforts towards reduced or zero ischaemia PN. These approaches were associated with strong functional recovery and some peri-operative risk, although they were generally safe in experienced hands. Further research demonstrated that, when parenchymal volume changes were incorporated into the analyses, ischaemia lost statistical significance, and percent parenchymal volume saved proved to be the main determinant. Cold ischaemia was confirmed to be highly protective, and limited warm ischaemia also proved to be safe. The reconstructive phase of PN, with avoidance of parenchymal devascularization, appears to be most important for functional outcomes. Randomized trials of on-clamp vs off-clamp PN have shown minimal impact of ischaemia on functional recovery.

CONCLUSIONS

The past decade has witnessed great progress regarding functional recovery after PN, with many lessons learned. However, there are still unanswered questions, including: What is the threshold of warm ischaemia at which irreversible ischaemic injury begins to develop? Are some cohorts at increased risk for AKI or irreversible ischaemic injury? and Which patients should be prioritized for zero-ischaemia PN?