Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

Does the transfer of knowledge from the pioneer generation to the second-generation speed-up the learning curve of robot-assisted partial nephrectomies? TRANSFER trial (UroCCR n°83)

Objectives

The objective is to compare the learning curves between two pioneer and three second-generation surgeons for RAPN in terms of WIT, CD and positive surgical margins.

Materials and methods

The charts of consecutive RAPNs of three centres were reviewed from the UroCCR prospective database. The experience was assessed by a regression model for each group. There was a univariate analysis on three consecutive sequences of 15 procedures. The learning speed for WIT was explored graphically by polynomial regression after cubic splines. Finally, CUSUM charts were obtained.

Results

There were 1203 RAPN in the pioneer group and 119 performed by second-generation surgeons. There was a significant difference in the distribution of tumour size (p < 0.001) and the RENAL score (p < 0.001). The operative time was longer in the first group (p > 0.001). Independent factors for a higher WIT were the second group (p < 0.001), higher experience (p < 0.001) the collinearity between the group and experience (p < 0.001), the RENAL score (p < 0.001) and blood loss (p < 0.001). Adjusted Loess regressions showed a plateau of WIT at 400 procedures for the pioneers and a significant decrease at 20 procedures for the second generation. CUSUM chart analysis showed a 'staircase' pattern of the learning process, with three major steps at 150, 200 and 300 procedures. The major limitation is the difference in sample size between the two arms.

Conclusions

Learning curve patterns would reflect a transfer of knowledge to the second-generation, as opposed to the establishment of standards by the pioneers.

French AFU Cancer Committee Guidelines - Update 2024-2026: Management of kidney cancer

OBJECTIVE

To update the French recommendations for the management of kidney cancer.

METHODS

A systematic review of the literature was conducted for the period from 2014 to 2024. The most relevant articles concerning the diagnosis, classification, surgical treatment, medical treatment, and follow-up of kidney cancer were selected and incorporated into the recommendations. The recommendations have been updated specifying the level of evidence (strong or weak).

RESULTS

Kidney cancer following prolonged occupational exposure to trichloroethylene should be considered an occupational disease. The reference examination for the diagnosis and staging of kidney cancer is the contrast-enhanced thoraco-abdominal CT scan. PET scans are not indicated in the staging of kidney cancer. Percutaneous biopsy is recommended in situations where its results will influence therapeutic decisions. It should be used to reduce the number of surgeries for benign tumors, particularly avoiding unnecessary radical nephrectomies. Kidney tumors should be classified according to the pTNM 2017 classification, the WHO 2022 classification, and the ISUP nucleolar grade. Metastatic kidney cancers should be classified according to IMDC criteria. Surveillance of tumors smaller than 2cm should be prioritized and can be offered regardless of patient age. Robot-assisted laparoscopic partial nephrectomy is the reference surgical treatment for T1 tumors. Ablative therapies and surveillance are options for elderly patients with comorbidities for tumors larger than 2cm. Stereotactic radiotherapy is an option to discuss for treating localized kidney tumors in patients not eligible for other treatments. Radical nephrectomy is the first-line treatment for locally advanced localized cancers. Pembrolizumab is recommended for patients at high risk of recurrence after surgery for localized kidney cancer. In metastatic patients, cytoreductive nephrectomy can be immediate in cases of good prognosis, delayed in cases of intermediate or poor prognosis for patients stabilized by medical treatment, or as "consolidation" in patients with complete or major partial response at metastatic sites after systemic treatment. Surgical or local treatment of metastases can be proposed for single lesions or oligometastases. Recommended first-line drugs for metastatic clear cell renal carcinoma are combinations of axitinib/pembrolizumab, nivolumab/ipilimumab, nivolumab/cabozantinib, and lenvatinib/pembrolizumab. Patients with non-clear cell metastatic kidney cancer should be presented to the CARARE Network and prioritized for inclusion in clinical trials.

CONCLUSION

These updated recommendations are a reference that will enable French and French-speaking practitioners to optimize their management of kidney cancer.

Robotic partial nephrectomy: Indications, patient selection, and setup for success

Robot-assisted partial nephrectomy (RAPN) has readily become the benchmark treatment of small renal masses (SRMs). The management of SRMs is focused on preserving renal function and limiting the morbidity of a traditional open operation, thus greatly impacting overall prognosis and long-term survival. Indications and techniques have evolved over the last 2 decades. In this article, we discuss the application of this nephron-sparing technique regarding its indications, surgical considerations, and functional outcomes.

On-clamp vs off-clamp robot-assisted partial nephrectomy for achieving modified trifecta: inverse probability of treatment weighting analysis from a high-volume tertiary robotic center

On-clamp partial nephrectomy for the surgical treatment of renal masses poses the risk of ischemia and greater post-operative renal function loss. Conversely, the off-clamp technique might enhance renal function preservation by avoiding any ischemia time. Nevertheless, the debate persists regarding the efficacy of the on- versus off-clamp partial nephrectomy in achieving better surgical, functional, and oncological outcomes. We retrospectively assessed the data from patients undergoing Robot-Assisted Partial Nephrectomy (RAPN) from 2016 and 2023 in a tertiary robotic center. Inverse probability of treatment weighting (IPTW) was used to account for selection bias in treatment allocation. The main objective of the study was assessing the achievement rates of a modified trifecta within the two groups. Multivariable logistic regression analysis (MLRA) was employed to assess the predictors of trifecta achievement. 532 patients were included in the analysis, of whom 74.1% vs. 25.9% underwent on- and off-clamp, respectively. Balancing the two groups for the main predictors of on-clamp surgery, there were no significant differences between on- and off-clamp in terms of estimated blood loss, transfusion rate, intra- and post-operative complications, positive surgical margins, and post-operative mean reduction of eGFR. Finally, no differences were found in the rate of "trifecta" achievement between on-clamp and off-clamp RAPN (24.6% vs. 21%, p = 0.82). At MLRA, off-clamp technique was not a predictor of trifecta achievement compared to the on-clamp technique (off-clamp vs. on-clamp, aOR 1.24, 95% CIs [0.65-2.36], p = 0.58). Our study revealed that clamping technique does not imply clinically relevant differences in reaching trifecta outcomes.

Parenchymal volume preservation during partial nephrectomy: improved methodology to assess impact and predictive factors

OBJECTIVE

To rigorously evaluate the impact of the percentage of parenchymal volume preserved (PPVP) and how well the preserved parenchyma recovers from ischaemia (Recischaemia) on functional outcomes after partial nephrectomy (PN) using an accurate and objective software-based methodology for estimating parenchymal volumes and split renal function (SRF). A secondary objective was to assess potential predictors of the PPVP.

PATIENTS AND METHODS

A total of 894 PN patients with available studies (2011-2014) were evaluated. The PPVP was measured from cross-sectional imaging at ≤3 months before and 3-12 months after PN using semi-automated software. Pearson correlation evaluated relationships between continuous variables. Multivariable linear regression evaluated predictors of ipsilateral glomerular filtration rate (GFR) preserved and the PPVP. Relative-importance analysis was used to evaluate the impact of the PPVP on ipsilateral GFR preserved. Recischaemia was defined as the percentage of ipsilateral GFR preserved normalised by the PPVP.

RESULTS

The median tumour size and R.E.N.A.L. nephrometry score were 3.4 cm and 7, respectively. In all, 49 patients (5.5%) had a solitary kidney. In all, 538 (60%)/251 (28%)/104 (12%) patients were managed with warm/cold/zero ischaemia, respectively. The median pre/post ipsilateral GFRs were 40/31 mL/min/1.73 m2, and the median (interquartile range [IQR]) percentage of ipsilateral GFR preserved was 80% (71-88%). The median pre/post ipsilateral parenchymal volumes were 181/149 mL, and the median (IQR) PPVP was 84% (76-92%). In all, 330 patients (37%) had a PPVP of <80%, while only 34 (4%) had a Recischaemia of <80%. The percentage of ipsilateral GFR preserved correlated strongly with the PPVP (r = 0.83, P < 0.01) and loss of parenchymal volume accounted for 80% of the loss of ipsilateral GFR. Multivariable analysis confirmed that the PPVP was the strongest predictor of ipsilateral GFR preserved. Greater tumour size and endophytic and nearness properties of the R.E.N.A.L. nephrometry score were associated with a reduced PPVP (all P ≤ 0.01). Solitary kidney and cold ischaemia were associated with an increased PPVP (all P < 0.05).

CONCLUSIONS

A reduced PPVP predominates regarding functional decline after PN, although a low Recischaemia can also contribute. Tumour-related factors strongly influence the PPVP, while surgical efforts can improve the PPVP as observed for patients with solitary kidneys.

Renal Function Preservation in Purely Off-Clamp Sutureless Robotic Partial Nephrectomy: Initial Experience and Technique

The aim of our study is to evaluate the effectiveness and safety of a sutureless off-clamp robot-assisted partial nephrectomy (sl-oc RAPN), particularly its impact on renal function. A multicenter study was conducted from April 2021 to June 2022. Patients diagnosed with a renal mass of >2 cm and a PADUA score of ≤6 consecutively underwent an sl-oc RAPN procedure. Tumor features, patients characteristics, and intraoperative outcomes were assessed. An evaluation of renal function was performed preoperatively, and again at 1 and 3 months after surgery by measuring the creatinine and blood urea nitrogen levels. The renal function of the two separate kidneys was assessed by a sequential renal scintigraphy performed before and at least 30 days after surgery. A total of 21 patients underwent an sl-oc RAPN. The median age was 64 years (IQR 52/70), the median tumor diameter was 40 mm (IQR 29/45), and the median PADUA score was 4 (3.5/5). The intraoperative outcomes included operative time (OT), 90 (IQR 74/100) min; estimated blood loss (EBL), 150 (IQR 50/300) mL; and perioperative complications, CD > 3 1(5%); only two patients presented positive surgical margins in their final histology (2/21, 10%). Compared to the preoperative value, a decrease in renal function was highlighted with a statistically significant median decrease of 10 mL/min (p < 0.01). The renal scintigraphy showed an overall decrease in renal function compared to the preoperative value, with a range in the operated kidney that varied from 0 to 15 mL/s and from 0% to 40%, with a median value of 4 mL/s and 12%. sl-oc RAPN is a safe procedure, with a minimal impact on kidney function alteration. This technique has proven effective in preserving renal function and maintaining optimal oncological outcomes with limited complications.

The evolving management of small renal masses

Small renal masses (SRMs) are a heterogeneous group of tumours with varying metastatic potential. The increasing use and improving quality of abdominal imaging have led to increasingly early diagnosis of incidental SRMs that are asymptomatic and organ confined. Despite improvements in imaging and the growing use of renal mass biopsy, diagnosis of malignancy before treatment remains challenging. Management of SRMs has shifted away from radical nephrectomy, with active surveillance and nephron-sparing surgery taking over as the primary modalities of treatment. The optimal treatment strategy for SRMs continues to evolve as factors affecting short-term and long-term outcomes in this patient cohort are elucidated through studies from prospective data registries. Evidence from rapidly evolving research in biomarkers, imaging modalities, and machine learning shows promise in improving understanding of the biology and management of this patient cohort.

Tracing the evolving dynamics and research hotspots in the kidney neoplasm and nephron sparing surgery field from the past to the new era

BACKGROUND

With increasing detection of small renal masses and accumulating evidence that nephron sparing surgery (NSS) could achieve oncological equivalence and functional superiority compared with radical nephrectomy (RN), NSS has become first-line therapy for some patients with localized renal masses.

OBJECTIVE

This study aims to review the publications in the kidney neoplasm and NSS field, exploring the research hotspots.

METHOD

Kidney neoplasm and NSS related publications before July 3th 2023 were obtained from the Web of Science Core Collection database. We then used bibliometric analysis to conduct performance analysis, citation analysis and co-citation network of publications, together with keyword co-occurrence analysis.

RESULTS

Seven thousand five hundred and sixty-four documents were finally retrieved, and the annual publications increased exponentially. The most productive authors were "KAOUK JH" and "GILL IS", while USA, and 12 American affiliations such as CLEVELAND CLINIC FOUNDATION and MAYO CLINIC were far leading in this field. Journal of Urology and European Urology were journals with the highest citations and h-index.

DISCUSSION

Through literature reviewing plus co-occurrence and clustering analysis, the therapeutic effects of partial nephrectomy (PN) versus RN on patients with localized renal cell carcinoma, different operative approaches of PN, and conservative NSS methods were deemed as the most focused topics.

CONCLUSION

Three aspects were the most important hotspots in this field. Firstly, how to provide the optimal management choices for different patients. Secondly, therapeutic effects of different management options and surgical techniques needed more prospective and randomized studies. Finally, more novel technologies and surgical techniques were required.

Biophotonics-Intraoperative Guidance During Partial Nephrectomy: A Systematic Review and Meta-analysis

CONTEXT

Partial nephrectomy (PN) with intraoperative guidance by biophotonics has the potential to improve surgical outcomes due to higher precision. However, its value remains unclear since high-level evidence is lacking.

OBJECTIVE

To provide a comprehensive analysis of biophotonic techniques used for intraoperative real-time assistance during PN.

EVIDENCE ACQUISITION

We performed a comprehensive database search based on the PICO criteria, including studies published before October 2022. Two independent reviewers screened the titles and abstracts followed by full-text screening of eligible studies. For a quantitative analysis, a meta-analysis was conducted.

EVIDENCE SYNTHESIS

In total, 35 studies were identified for the qualitative analysis, including 27 studies on near-infrared fluorescence (NIRF) imaging using indocyanine green, four studies on hyperspectral imaging, two studies on folate-targeted molecular imaging, and one study each on optical coherence tomography and 5-aminolevulinic acid. The meta-analysis investigated seven studies on selective arterial clamping using NIRF. There was a significantly shorter warm ischemia time in the NIRF-PN group (mean difference [MD]: -2.9; 95% confidence interval [CI]: -5.6, -0.1; p = 0.04). No differences were noted regarding transfusions (odds ratio [OR]: 0.5; 95% CI: 0.2, 1.7; p = 0.27), positive surgical margins (OR: 0.7; 95% CI: 0.2, 2.0; p = 0.46), or major complications (OR: 0.4; 95% CI: 0.1, 1.2; p = 0.08). In the NIRF-PN group, functional results were favorable at short-term follow-up (MD of glomerular filtration rate decline: 7.6; 95% CI: 4.6, 10.5; p < 0.01), but leveled off at long-term follow-up (MD: 7.0; 95% CI: -2.8, 16.9; p = 0.16). Remarkably, these findings were not confirmed by the included randomized controlled trial.

CONCLUSIONS

Biophotonics comprises a heterogeneous group of imaging modalities that serve intraoperative decision-making and guidance. Implementation into clinical practice and cost effectiveness are the limitations that should be addressed by future research.

PATIENT SUMMARY

We reviewed the application of biophotonics during partial removal of the kidney in patients with kidney cancer. Our results suggest that these techniques support the surgeon in successfully performing the challenging steps of the procedure.

Functional recovery after partial nephrectomy in a solitary kidney

OBJECTIVES

Partial nephrectomy (PN) is the reference standard for renal mass in a solitary kidney (RMSK), although factors determining functional recovery in this setting remain poorly defined.

PATIENTS/METHODS

Single center, retrospective analysis of 841 RMSK patients (1975-2022) managed with PN with functional data, including 361/435/45 with cold/warm/zero ischemia, respectively. A total of 155 of these patients also had necessary studies for detailed analysis of parenchymal volume preserved. Acute kidney injury (AKI) was classified by RIFLE (Risk/Injury/Failure/Loss/Endstage). Recovery-from-ischemia (Rec-Ischemia) was defined as glomerular filtration rate (GFR) saved normalized by parenchymal volume saved. Logistic regression identified predictive factors for AKI and predictors of Rec-Ischemia were analyzed by multivariable linear regression.

RESULTS

Overall, median preoperative GFR was 56.7 ml/min/1.73m2 and new-baseline and 5-year GFRs were 43.1 and 44.5 ml/min/1.73m2, respectively. Median follow-up was 55 months; 5-year dialysis-free survival was 97%. In the detailed analysis cohort, a primary focus of this study, median warm (n = 70)/cold (n = 85) ischemia times were 25/34 minutes, respectively; and median preoperative, new-baseline and 5-year GFRs were 57.8, 45.0, and 41.7 ml/min/1.73m2, respectively. Functional recovery correlated strongly with parenchymal volume preserved (r = 0.84, p < 0.001). Parenchymal volume loss accounted for 69% of the total median GFR decline associated with PN, leaving only 3 to 4 ml/min/1.73m2 attributed to ischemia and other factors. AKI occurred in 52% of patients and the only independent predictor of AKI was ischemia time. Independent predictors of reduced Rec-Ischemia were increased age, warm ischemia, and AKI.

CONCLUSION

The main determinant of functional recovery after PN in RMSK is parenchymal volume preservation. Type/duration of ischemia, AKI, and age also correlated, although altogether their contributions were less impactful. Our findings suggest multiple opportunities for optimizing functional outcomes although preservation of parenchymal volume remains predominant. Long-term function generally remains stable with dialysis only occasionally required.

Renorrhaphy techniques in minimally invasive partial nephrectomy: a systematic review of the literature

INTRODUCTION

In the absence of consensus on the optimal approach to renorrhaphy in partial nephrectomy, this systematic review aims to assess the various renorrhaphy techniques and their impact on surgical outcomes.

EVIDENCE ACQUISITION

A systematic review of the literature was performed in March 2022, using PubMed and Scopus, without time restrictions and research filters for studies investigating renorrhaphy techniques in partial nephrectomy. Studies providing sufficient details on renorrhaphy techniques and their outcomes during minimally invasive partial nephrectomy (PN) were included in this analysis.

EVIDENCE SYNTHESIS

Thirty-one studies with 5720 patients were included in the analysis. In most studies, tumor diameter was <4 cm. RENAL and PADUA scores as well as tumor locations were heterogeneous between the studies. The results of the use of hemostatic agents were conflicting among different studies with limited evidence regarding the benefits of its routine use in partial nephrectomy. The use of barbed and running sutures was associated with a reduced warm ischemia time. While some studies showed a decreased warm ischemia time when omitting cortical renorrhaphy, others found that it may lead to higher incidence of minor complications without any significant improvement in other outcomes.

CONCLUSIONS

There is ongoing research to determine the optimal approach to renorrhaphy. The current evidence on the routine use of hemostatic agents is limited. The use of certain techniques such as barbed sutures, sliding clips and running sutures reduced the warm ischemia time. The omission of cortical renorrhaphy is still controversial.

The Association of Ischemia Type and Duration with Acute Kidney Injury after Robot-Assisted Partial Nephrectomy

BACKGROUND

Acute kidney injury (AKI) after robot-assisted partial nephrectomy (RAPN) is a robust surrogate for chronic kidney disease. The objective of this study was to evaluate the association of ischemia type and duration during RAPN with postoperative AKI.

MATERIALS AND METHODS

We reviewed all patients who underwent RAPN at our institution since 2011. The ischemia types were warm ischemia (WI), selective artery clamping (SAC), and zero ischemia (ZI). AKI was defined according to the Risk Injury Failure Loss End-Stage (RIFLE) criteria. We calculated ischemia time thresholds for WI and SAC using the Youden and Liu indices. Logistic regression and decision curve analyses were assessed to examine the association with AKI.

RESULTS

Overall, 154 patients met the inclusion criteria. Among all RAPNs, 90 (58.4%), 43 (28.0%), and 21 (13.6%) were performed with WI, SAC, and ZI, respectively. Thirty-three (21.4%) patients experienced postoperative AKI. We extrapolated ischemia time thresholds of 17 min for WI and 29 min for SAC associated with the occurrence of postoperative AKI. Multivariable logistic regression analyses revealed that WIT ≤ 17 min (odds ratio [OR] 0.1, p < 0.001), SAC ≤ 29 min (OR 0.12, p = 0.002), and ZI (OR 0.1, p = 0.035) significantly reduced the risk of postoperative AKI.

CONCLUSIONS

Our results confirm the commonly accepted 20 min threshold for WI time, suggest less than 30 min ischemia time when using SAC, and support a ZI approach if safely performable to reduce the risk of postoperative AKI. Selecting an appropriate ischemia type for patients undergoing RAPN can improve short- and long-term functional kidney outcomes.

Risks and benefits of partial nephrectomy performed with limited or with zero ischaemia time

OBJECTIVE

To test the hypothesis that longer warm ischaemia time (WIT) might have a marginal impact on renal functional outcomes and might, in fact, reduce haemorrhagic risk intra-operatively.

PATIENTS AND METHODS

Data from 1140 patients treated with elective partial nephrectomy (PN) for a cT1-2 cN0 cM0 renal mass were prospectively collected. WIT was defined as the duration of clamping of the main renal artery with no refrigeration and was tested as a continuous variable. The primary outcome of the study was evaluation of the effect of WIT on renal function (estimated glomerular filtration rate [eGFR]) postoperatively, at 6 months and in the long term (measured between 1 and 5 years after surgery). The secondary outcome of the study was haemorrhagic risk, defined as estimated blood loss (EBL) or peri-operative transfusions. Multivariable linear, logistic and Cox regression analyses, accounting for age, Charlson comorbidity index, clinical size, preoperative eGFR and year of surgery, were used and the potential nonlinear relationship between WIT and the study outcomes was modelled using restricted cubic splines.

RESULTS

A total of 863 patients (76%) underwent PN with WIT and 277 (24%) without. The baseline median eGFR was 87.3 (68.8-99.2) mL/min/1.73m2 for the on-clamp population and 80.6 (63.2-95.2) mL/min/1.73m2  for the off-clamp population. The median duration of WIT was 17 (13-21) min. At multivariable analyses predicting renal function, longer WIT was associated with decreased postoperative eGFR (estimate: -0.21, 95% confidence interval [CI] -0.31; -0.11 [P < 0.001]). Conversely, no association between WIT and eGFR was recorded at 6-month or long-term follow-up (all P > 0.8). At multivariable analyses predicting haemorrhagic risk, clampless resection with no ischaemia time and PN with short WIT was associated with an increased EBL (estimate: -21.56, 95% CI -28.33; -14.79 [P < 0.001]) and peri-operative transfusion rate (estimate: -0.009, 95% CI -0.01; -0.003 [P = 0.002]). No association between WIT and positive surgical margin status was recorded (all P = 0.1).

CONCLUSION

Patients and clinicians should be aware that performing PN with very limited or even with zero WIT might increase bleeding and the need for peri-operative transfusion while not improving long-term renal function outcomes.

Technologic advances in robot-assisted nephron sparing surgery: a narrative review

BACKGROUND AND OBJECTIVE

Nephron sparing surgery (NSS) is the preferred management for clinical stage T1 (cT1) renal masses. In recent years, indications have expanded to larger and more complex renal tumors. In an effort to provide optimal patient outcomes, urologists strive to achieve the pentafecta when performing partial nephrectomy. This has led to the continuous technologic advancement and technique refinement including the use of augmented reality, ultrasound techniques, changes in surgical approach and reconstruction, uses of novel fluorescence marker guided imaging, and implementation of early recovery after surgery (ERAS) protocols. The aim of this narrative review is to provide an overview of the recent advances in pre-, intra-, and post-operative management and approaches to managing patients with renal masses undergoing NSS.

METHODS

We performed a non-systematic literature search of PubMed and MEDLINE for the most relevant articles pertaining to the outlined topics from 2010 to 2022 without limitation on study design. We included only full-text English articles published in peer-reviewed journals.

KEY CONTENT AND FINDINGS

Partial nephrectomy is currently prioritized for cT1a renal masses; however, indications have been expanding due to a greater understanding of anatomy and technologic advances. Recent studies have demonstrated that improvements in imaging techniques utilizing cross-sectional imaging with three-dimensional (3D) reconstruction, use of color doppler intraoperative ultrasound, and newer studies emerging using contrast enhanced ultrasound play important roles in certain subsets of patients. While indocyanine green administration is commonly used, novel fluorescence-guided imaging including folate receptor-targeting fluorescence molecules are being investigated to better delineate tumor-parenchyma margins. Augmented reality has a developing role in patient and surgical trainee education. While pre-and intra-operative imaging have shown to be promising, near infrared guided segmental and sub-segmental vessel clamping has yet to show significant benefit in patient outcomes. Studies regarding reconstructive techniques and replacement of reconstruction with sealing agents have a promising future. Finally, ERAS protocols have allowed earlier discharge of patients without increasing complications while improving cost burden.

CONCLUSIONS

Advances in NSS have ranged from pre-operative imaging techniques to ERAS protocols Further prospective investigations are required to determine the impact of novel imaging, in-vivo fluorescence biomarker use, and reconstructive techniques on achieving the pentafecta of NSS.

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.

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.

Impact of Warm Ischemia on Acute Kidney Injury After Robotic Partial Nephrectomy Stratified by Baseline Kidney Function

Objectives: To evaluate the differences in baseline chronic kidney disease (CKD) status in correlations between warm ischemic time (WIT) and acute kidney injury (AKI) or acute/chronic renal function change after robot-assisted partial nephrectomy (RAPN). Methods: This study retrospectively recruited 1290 patients from a multi-institutional RAPN database. The patients were grouped into four preoperative CKD categories: CKD Group 1 (CKDG1), CKD Group 2 (CKDG2), CKD Group 3a (CKDG3a), and CKD Group 3b (CKDG3b). The correlation between WIT and the probability of AKI was assessed according to the baseline CKD grade, together with changes in serum creatinine (sCr) at the postoperative maximum and chronic renal function. Results: AKI was not observed in the CKDG1 group. The probability of AKI at WIT = 30 minutes was 5.6% for CKDG2, 8.5% for CKDG3a, and 11.6% for CKDG3b (all p < 0.05). WIT was an independent predictor of AKI occurrence in the multivariate model for these three CKD groups. Significant weak correlations were observed between WIT and sCr change for all four groups, with R² = 0.22 for CKDG1, R² = 0.16 for CKDG2, R² = 0.03 for CKDG3a, and R² = 0.09 for ≥CKDG3b. For chronic renal function, correlations were significant in CKDG2, CKDG3a, and ≥CKDG3b, yet R² was considered small in all cases (<0.1). Conclusions: The association between extended WIT and the probability of AKI increased in patients with more severe baseline CKD. The correlation between WIT and renal function was significant, yet clinically modest.

Systemic Changes in Endocannabinoids and Endocannabinoid-like Molecules in Response to Partial Nephrectomy-Induced Ischemia in Humans

Renal ischemia-reperfusion (IR), a routine feature of partial nephrectomy (PN), can contribute to the development of acute kidney injury (AKI). Rodent studies show that the endocannabinoid system (ECS) is a major regulator of renal hemodynamics and IR injury; however, its clinical relevance remains to be established. Here, we assessed the clinical changes in systemic endocannabinoid (eCB) levels induced by surgical renal IR. Sixteen patients undergoing on-clamp PN were included, with blood samples taken before renal ischemia, after 10 min of ischemia time, and 10 min following blood reperfusion. Kidney function parameters (serum creatinine (sCr), blood urea nitrogen (BUN), and serum glucose) and eCB levels were measured. Baseline levels and individual changes in response to IR were analyzed and correlation analyses were performed. The baseline levels of eCB 2-arachidonoylglycerol (2-AG) were positively correlated with kidney dysfunction biomarkers. Unilateral renal ischemia increased BUN, sCr, and glucose, which remained elevated following renal reperfusion. Renal ischemia did not induce changes in eCB levels for all patients pooled together. Nevertheless, stratifying patients according to their body mass index (BMI) revealed a significant increase in N-acylethanolamines (anandamide, AEA; N-oleoylethanolamine, OEA; and N-palmitoylethanolamine, PEA) in the non-obese patients. No significant changes were found in obese patients who had higher N-acylethanolamines baseline levels, positively correlated with BMI, and more cases of post-surgery AKI. With the inefficiency of 'traditional' IR-injury 'preventive drugs', our data support future research on the role of the ECS and its manipulation in renal IR.

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?

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.

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.

The Role of Intraoperative Ultrasonography Associated with Clampless Technique in Three-Dimensional Retroperitoneoscopic Laparoscopic Enucleation of Completely Endophytic Renal Tumors

Objectives: To evaluate perioperative and functional outcomes of clampless laparoscopic tumor enucleation for completely endophytic renal tumors with the guide of intraoperative ultrasonography. Methods: We analyzed patients with clinically completely endophytic tumors, renal tumors, who underwent clampless three-dimensional (3D) retroperitoneoscopic laparoscopic tumor enucleation between January 2012 and January 2021. Patients with exophytic tumors were excluded. Intraoperative ultrasonography was used to map out the mass in all surgeries. Results: Overall, 57 patients underwent clampless 3D retroperitoneoscopic laparoscopic tumor enucleation. Mean surgical time was 131 minutes, and mean estimated blood loss was 202 mL. Mean hospital stay was 4.7 days. Major and minor postoperative complications occurred, respectively, in 3 and 10 cases. Only a patient had a positive surgical margin. One-year renal function did not differ from baseline. Conclusion: Our study showed that clampless laparoscopic enucleation guided by laparoscopic ultrasonography ensured satisfactory outcomes for completely intrarenal tumors, with excellent renal function preservation 1 year after surgery.

Changes in kidney function according to ischemia type during partial nephrectomy for T1a kidney cancer

To compare the postoperative estimated-glomerular-filtration-rate (eGFR) and parenchymal changes between cold ischemia and zero/selective ischemia for a T1a mass. We analyzed 104 patients who underwent open partial nephrectomy with cold ischemia (53) or zero/selective ischemia (51) for T1a between 2008 and 2018 to determine postoperative renal function changes and associated factors. Postoperative renal function was expressed as (postoperative-eGFR - preoperative-eGFR)/preoperative-eGFR × 100%. Parenchymal enhancement and thicknesses of the ipsilateral kidney as tissue changes were measured on postoperative CT to identify the correlation with the renal function change. Patients with 10% or 25% decrease in eGFR were significantly more in the cold ischemia group (p = 0.032, p = 0.006). On multivariable analysis, preoperative eGFR, ischemic type, and percent change of parenchymal thickness were identified to be significantly associated with postoperative 12 months renal function (B = - 0.367, p = 0.020; B = 6.788, p = 0.042; B = 0.797, p = 0.029). Change in parenchymal thickness was negatively correlated with changes in postoperative renal function (r = - 0.277, p = 0.012). Changes in eGFR were associated with a decrease in parenchymal thickness and the type of ischemic technique. Zero/selective ischemia during partial nephrectomy may have an advantage in preserving postoperative renal function compared to cold ischemia.

Comparison of Perioperative, Renal Functional, and Oncological Outcomes Between Off-Clamp and On-Clamp Robot-Assisted Partial Nephrectomy for Renal Tumors: An Updated Evidence-Based Analysis

Objectives

We aimed to report the latest and largest pooled analysis and evidence update to compare the perioperative, renal functional, and oncological outcomes between off-clamp and on-clamp robot-assisted partial nephrectomy (RAPN) for renal tumors.

Patients and methods

We performed a systematic literature search using PubMed, Embase, and Web of Science up to August 2021 for studies that compared the efficacy and/or safety between off-clamp and on-clamp RAPN for renal tumors. Outcomes measured were operating time, estimated blood loss (EBL), conversion rate, length of stay (LOS), complication rate, transfusion rate, long-term % decrease in estimated glomerular filtration rate (eGFR), positive surgical margin rate, and recurrence rate.

Results

A total of 21 eligible articles involving 4,493 patients (1,274 off-clamp versus 3,219 on-clamp) were included for the evidence synthesis. Baseline characteristics of the two groups were similar in all outcomes except that lower R.E.N.A.L. score and smaller tumor size were observed in the off-clamp group. Pooled analysis showed shorter operative time, higher EBL, and lower complication rate in the off-clamp group. No significant difference was observed in the conversion rate, LOS, and transfusion rate. The recurrence rates were similar in the two groups, while a lower positive surgical margin rate was observed in the off-clamp group. Finally, the off-clamp group had a superior postoperative renal functional outcome.

Conclusions

Given the presence of heterogeneity and potential bias, urologists should select the clamp strategy based on their experience and patient-specific factors.

Robotic-Assisted Partial Nephrectomy: Techniques to Improve Clinical Outcomes

PURPOSE OF REVIEW

To summarize current options available for robot-assisted partial nephrectomy RECENT FINDINGS: Partial nephrectomy (PN) is a standard treatment option for management of cT1 renal masses. It may be carried out by multiple approaches. Robot-assisted (RA) PN is one such option. The goal of treatment is both correct oncological (negative surgical margins) and functional (preservation of sufficient amount of renal parenchyma of the operated kidney) outcome. Appropriate outcomes depend on multiple factors. There are many, but among others tumor characteristics (size, location, i.e., tumor complexity), patient baseline renal function, patient comorbidities, and performance status etc. Based on all these, the surgeon adapts the intervention for each mass/patient by preoperative planning, absence/use/duration of warm or cold ischemia, perioperative imaging, resection technique adapted to tumor location and depth of invasion, use of hemostatics, type and degree of renal parenchymal closure and others details. Nephroprotective agents have not shown efficacy so far. It should not be forgotten that surgeon's experience plays a key role in the achievement of good results. Although multiple factors have a role in the RA partial nephrectomy, surgeon experience and adaptation of technique of intervention have the crucial role in the achievement of both functional and oncological results.

Three-dimensional (3D) reconstruction and navigation in robotic-assisted partial nephrectomy (RAPN) for renal masses in the solitary kidney: A comparative study

BACKGROUND

Numerous efforts were made to improve renal function and oncologic outcomes in surgery for patients with kidney cancer. We explored new robotic methods in solitary kidneys.

MATERIALS AND METHODS

We prospectively registered and included 16 patients in the 3D-robot-assisted partial nephrectomy (RAPN) group with a solitary kidney (anatomic or functional), and retrospectively identified 25 patients with a solitary kidney who received RAPN also operated by us for comparison.

RESULTS

The rates of global clamping reduced in the 3D-RAPN group (37.5% vs 76%)while selective rates were higher (56.2% vs 20%) (p = 0.028). The mean percentages of Scr increase (+20.2% vs +30.2%, p = 0.045) and eGFR reduction (-16.8% vs -27.1%) as well as rate of opening collecting systems (31.3% vs 72%, p = 0.010) were lower in 3D-RAPN group.

CONCLUSIONS

3D-RAPN less impaired the renal function of patients with a solitary kidney and showed superiority or non-inferiority in other evaluation indexes compared to conventional RAPN.

Limited impact of warm ischemic threshold for partial nephrectomy in the robotic surgery era: A propensity score matching study

OBJECTIVES

To evaluate the association between extended (≥30 min) warm ischemic time and renal function in patients undergoing robot-assisted partial nephrectomy.

METHODS

This multi-institutional study retrospectively recruited 1131 patients who underwent robot-assisted partial nephrectomy. Patients were classified into shorter (<30 min; n = 1038) and longer (≥30 min; n = 92) groups based on the ischemic time required, and 1:2 propensity score matching was used to minimize selection bias. The perioperative outcomes, including acute kidney injury and trifecta attainment, and mid/long-term renal function were assessed before and after matching.

RESULTS

Patients in the longer group had tumors with a significantly larger diameter and RENAL nephrometry score. The decline in the nadir of the estimated glomerular filtration rate was significantly greater in the longer than the shorter group in the unmatched and matched cohorts (-16.2 vs -5.5%, P < 0.001; 15.5 vs -9.5%, P = 0.003, respectively). A higher incidence of acute kidney injury (9.8 vs 2.6%, P = 0.002) was observed in the longer group before matching, whereas the difference was comparable after matching. Before matching, the decline in estimated glomerular filtration rate at 6 months postoperatively was greater (-8.2 vs -5.1%, P = 0.005) and trifecta attainment was lower (50.0 vs 63.5%, P < 0.001) in the longer group. However, the differences were comparable for both the parameters between the groups in the matched cohort.

CONCLUSIONS

While extended warm ischemia during robot-assisted partial nephrectomy can be demanded in case of large and complex tumors, its impact on postoperative renal function is limited.

Warm ischemia time length during on-clamp partial nephrectomy: dose it really matter?

BACKGROUND

The impact of warm ischemia time (WIT) on renal functional recovery remains controversial. We examined the length of WIT >30 min. on the long-term renal function following on-clamp partial nephrectomy (PN).

METHODS

Data from 23 centers for patients undergoing on-clamp PN between 2000 and 2018 were analyzed. We included patients with two kidneys, single tumor, cT1, minimum 1-year followup, and preoperative eGFR ≥60 ml/min/1.73m2. Patients were divided into two groups according to WIT length: group Ⅰ "WIT ≤30 min." and group Ⅱ "WIT >30 min.". A propensity-score matched analysis (1:1 match) was performed to eliminate potential confounding factors between groups. We compared eGFR values, eGFR (%) preservation, eGFR decline, events of chronic kidney disease (CKD) upgrading, and CKD-free progression rates between both groups. Cox regression analysis evaluated WIT impact on upgrading of CKD stages.

RESULTS

The primary cohort consisted of 3526 patients: group Ⅰ (n=2868) and group Ⅱ (n=658). After matching the final cohort consisted of 344 patients in each group. At last followup, there were no significant differences in median eGFR values at 1, 3, 5, and 10 years (P>0.05) between the matched groups. In addition, the median eGFR (%) preservation and absolute eGFR change were similar (89% in group Ⅰ vs. 87% in group Ⅱ, p=0.638) and (-10 in group Ⅰ vs. -11 in group Ⅱ, p=0.577), respectively. The 5 years new-onset CKD-free progression rates were comparable in the non-matched groups (79% in group Ⅰ vs. 81% in group Ⅱ, log-rank, p=0.763) and the matched groups (78.8% in group Ⅰ vs. 76.3% in group Ⅱ, log-rank, p=0.905). Univariable Cox regression analysis showed that WIT >30 min. was not a predictor of overall CKD upgrading (HR:0.953, 95%CI 0.829-1.094, p=0.764) nor upgrading into CKD stage ≥Ⅲ (HR:0.972, 95%CI 0.805-1.173, p=0.764). Retrospective design is a limitation of our study.

CONCLUSIONS

Our analysis based on a large multicenter international cohort study suggests that WIT length during PN has no effect on the long-term renal function outcomes in patients having two kidneys and preoperative eGFR ≥60 ml/min/1.73m2.

Is off-clamp robot-assisted partial nephrectomy beneficial for renal function? Data from the CLOCK trial

OBJECTIVES

To compare the functional outcomes of on- vs off-clamp robot-assisted partial nephrectomy (RAPN) within a randomized controlled trial (RCT).

MATERIALS AND METHODS

The CLOCK study (CLamp vs Off Clamp the Kidney during robotic partial nephrectomy; NCT02287987) is a multicentre RCT including patients with normal baseline function, two kidneys and masses with RENAL scores ≤ 10. Pre- and postoperative renal scintigraphy was prescribed. Renal defatting and hilum isolation were required in both study arms; in the on-clamp arm, ischaemia was imposed until the completion of medullary renorraphy, while in the off-clamp condition it was not allowed throughout the procedure. The primary endpoint was 6-month absolute variation in estimated glomerular filtration rate (AV-GFR); secondary endpoints were: 12, 18 and 24-month AV-GFR; 6-month estimated glomerular filtration rate variation >25% rate (RV-GFR >25); and absolute variation in ipsilateral split renal function (AV-SRF). The planned sample size was 102 + 102 cases, after taking account crossover of cases to the alternate study arm; a 1:1 randomization was performed. AV-GFR and AV-SRF were compared using analysis of covariation, and RV-GFR >25 was assessed using multivariable logistic regression. Intention-to-treat (ITT) and per-protocol analyses (PP) were performed.

RESULTS

A total of 160 and 164 patients were randomly assigned to on- and off-clamp RAPN, respectively; crossover was observed in 14% and 43% of the on- and off-clamp arms, respectively. We were unable to find any statistically significant difference between on- vs off-clamp with regard to the primary endpoint (ITT: 6-month AV-GFR -6.2 vs -5.1 mL/min, mean difference 0.2 mL/min, 95% confidence interval [CI] -3.1 to 3.4 [P = 0.8]; PP: 6-month AV-GFR -6.8 vs -4.2 mL/min, mean difference 1.6 mL/min, 95% CI -2.3 to 5.5 [P = 0.7]) or with regard to the secondary endpoints. The median warm ischaemia time was 14 vs 15 min in the ITT analysis and 14 vs 0 min in the PP analysis.

CONCLUSION

In patients with regular baseline function and two kidneys, we found no evidence of differences in functional outcomes for on- vs off-clamp RAPN.

How to improve outcome in nephron-sparing surgery: the impact of new techniques

PURPOSE OF REVIEW

Nephron-sparing partial nephrectomy is the state of the art for localized small renal mass and it is gaining attention also for more advanced cases. In the present narrative review, we discuss the new developments that have occurred in the advancement of this approach over the past few years.

RECENT FINDINGS

Off-clamp, selective/superselective clamp and early-unclamping techniques are safe and feasible approaches, with potentially superior functional outcomes, and noninferior complications rate and oncological outcomes, when compared with main artery clamping. Renorrhaphy must preserve the physiological vascularization of residual parenchyma. Running sutures, particularly using barbed wires, shorten the operating and ischemia times. A further advantage could derive from avoiding a double-layer suture. Transperitoneal robot-assisted partial nephrectomy (RAPN) and retroperitoneal RAPN can be considered equivalent in terms of perioperative morbidity, functional and oncologic outcomes, regardless of tumor's location, thus the choice of the approach should be driven by the surgeon's expertise. Future improvements should be introduced by the single-port robotic surgery, which seems to be safe and feasibly also in an off-clamp manner.

SUMMARY

Significant advances have recently been achieved in nephron-sparing surgery technique. However, future studies with standardized reporting of these new techniques are needed to assess the real impact of them on early and long-term functional outcomes.

Robotic renal and adrenal oncologic surgery: A contemporary review

Robot-assisted surgery has evolved over time. Radical nephrectomy with inferior vena cava thrombectomy is feasible and safe for level I, II and III thrombus in high volume centers. Though it is feasible for level IV thrombus, this procedure needs a multi-departmental co-operation. However, the safety of robot-assisted procedures in this subset is still unknown. Robot-assisted partial nephrectomy has been universally approved and found oncologically safe. Robotic adrenalectomy has been increasingly utilized for select cases, especially in bilateral tumors and for retroperitoneal adrenalectomy.

Robot-assisted partial nephrectomy versus standard laparoscopic partial nephrectomy for renal hilar tumor: A prospective multi-institutional study

OBJECTIVE

To investigate whether robot-assisted partial nephrectomy compared with laparoscopic partial nephrectomy is effective for renal hilar tumor removal.

METHODS

This was a prospective, multicenter, single-arm, open-label trial with a 2-year enrollment period. A total of 22 academic hospitals in Japan participated in the present study. Comparison with historical control values from reported studies of laparoscopic partial nephrectomy was carried out. The warm ischemia time and positive surgical margin rate were set as primary perioperative and oncological outcomes. In the historical control group, these were 27.7 min and 13%, respectively.

RESULTS

The analysis population included 105 participants. The mean warm ischemia time was 20.2 (95% confidence interval 16.7-21.8; P < 0.0001 vs 27.7). Two of 103 participants (1.9%) had a positive surgical margin (95% confidence interval 0.5-6.8%). Both results satisfy the prespecified decision criteria for the superiority of robot-assisted partial nephrectomy over the historical control of laparoscopic partial nephrectomy. Resected weight and preoperative estimated glomerular filtration rate were predictive factors of functional loss of the partially nephrectomized kidney after robot-assisted partial nephrectomy.

CONCLUSION

Robot-assisted partial nephrectomy for clinical T1 renal hilar tumors results in shorter warm ischemia time than and comparable positive surgical margin rate to those reported for laparoscopic partial nephrectomy.

Renal function after partial nephrectomy following intra-arterial embolization of renal tumors

Laparoscopic Partial Nephrectomy (LPN) after intra-arterial Embolization of renal tumors (LPNE) in a hybrid operating room allows renal tumor enucleation without dissection and clamping of the renal pedicle. The purpose was to assess the potential negative impact of embolization on the renal function. This prospective monocentric study included all patients treated with LPNE between May 2015 and June 2019. Clinical data was collected and incorporated into the UroCCR database (NCT03293563). Glomerular Filtration Rate (GFR) and Computed Tomography Renal Volume (CTRV) were compared before and after 6 months following LPNE. The mean post-operative GFR was 86.6 mL/min (SD 22.9). The mean GFR loss was 9.4% (SD 15.1) and the median renal parenchyma loss was 21 mL (SD 20.6). Using a threshold of 25% GFR loss, age was the only significant predictive factor of renal function impairment according to bivariate (59.5 vs 69.3 years, p = 0.017) and multivariable analysis (OR 1.075, CI 1–1.2], p = 0.05). Significant renal function impairment was not correlated with the renal parenchymal volume loss (OR 0.987, CI [0.95–1.02], p = 0.435). Renal function impairment after LPNE seems to be comparable to other techniques of partial nephrectomy.

Role of minimally invasive partial nephrectomy in the management of renal mass

Partial nephrectomy is recommended for surgical management of small renal masses (SRM), or lesions ≤7 cm. The decision for surgical intervention involves a balanced patient assessment. Minimally invasive approach, which includes laparoscopic and robotic techniques, has shown to have improved blood loss, length of hospitalization, and post-operative pain while maintaining oncologic efficacy when compared to an open approach. Transperitoneal approach is preferred at most centers; however, retroperitoneoscopic minimally invasive surgery (MIS) partial nephrectomy expertise is essential for comprehensive kidney cancer care. With advances in surgical technology and deep penetration of robotics into surgical training and practice, robotic partial nephrectomy has become the modality of choice in modern clinical practice. This review discusses the indications and outcomes for various minimally invasive approaches of partial nephrectomy.

Robotic Partial Nephrectomy: Update on Techniques

Surgical techniques for robot-assisted partial nephrectomy are driven by the aims of simplifying the most challenging surgical steps, maximizing functional and oncologic outcomes, and consistently pushing the envelope on possibilities. Over the past several years, we have seen an emergence in not only innovation in surgical technique, and robotic platforms, but integration of a variety of imaging techniques. We believe with developing robotic expertise, practicing urologists will continue to push the envelope in nephron preservation and complication-free recovery.

Laparoscopic Versus Open Partial Nephrectomy: A Systemic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

Purpose

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes between laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN).

Materials and Methods

Through a systematical search of multiple scientific databases in March 2020, we performed a systematic review and cumulative meta-analysis. Meanwhile, we assessed the quality of the relevant evidence according to the framework in the Cochrane Handbook for Systematic Reviews of Interventions.

Results

A total of 26 studies with 8095 patients were included. There was no statistical difference between the LPN and OPN in the terms of operation time (p=0.13), intraoperative complications (p=0.94), recurrence (p=0.56), cancer-specific survival (p=0.72), disease-free survival (p=0.72), and variations of estimated glomerular filtration rate (p=0.31). The LPN group had significantly less estimated blood loss (P<0.00001), lower blood transfusion (p=0.04), shorter length of hospital stay (p<0.00001), lower total (p=0.03) and postoperative complications (p=0.02), higher positive surgical margin (p=0.005), higher overall survival (p<0.00001), and less increased serum creatinine (p=0.002). The subgroup analysis showed that no clinically meaningful differences were found for T1a tumors in terms of operation time (p=0.11) and positive surgical margin (p=0.23). In addition, the subgroup analysis also suggested that less estimated blood loss (p<0.0001) and shorter length of hospital stay (p<0.00001) were associated with the LPN group for T1a tumors.

Conclusions

This meta-analysis revealed that the LPN is a feasible and safe alternative to the OPN with comparable surgical, oncologic, and functional outcomes. However, the results should be applied prudently in the clinic because of the low quality of evidence. Further quality studies are needed to evaluate the effectiveness LPN and its postoperative quality of life compared with OPN.

Effectiveness and safety of partial nephrectomy-no ischemia vs. warm ischemia: Systematic review and meta-analysis

PURPOSE

This study aimed to determine the effectiveness and safety of partial nephrectomy (PN) without ischemia compared with PN with warm ischemia for reducing the deterioration in renal function in patients with cT1 renal tumors.

MATERIALS AND METHODS

We conducted a systematic review that included patients over 18 years of age who underwent PN with or without warm ischemia for cT1 renal tumors. The primary outcome was impaired renal function. A search strategy was performed in MEDLINE, EMBASE, LILACS, CENTRAL, the article reference lists, and the unpublished literature to reach saturation of the information. We assessed the risk of bias with the methodological index for nonrandomized studies (MINORS) tool, and we performed a meta-analysis according to the type of variable.

RESULTS

We found a total of 5,682 articles, of which 14 met the inclusion criteria. Seven studies evaluated renal function, identifying a difference in means (MD) of 3.50 (95% confidence interval [CI], 1.16 to 5.83), favoring no ischemia. We did not find any significant differences regarding intraoperative bleeding or operative time (MD, 55 mL; 95% CI, -33.16 to 144.08; and MD, 1.87; 95% CI, -20.47 to 24.21; respectively).

CONCLUSIONS

In this study, PN without ischemia showed a decrease in deterioration of the estimated glomerular filtration rate compared with warm ischemia.

Functional and oncological outcomes of 3D clampless sutureless laparoscopic partial nephrectomy for renal tumors with low nephrometry score

BACKGROUND

Renal cell carcinoma still represents 2-3% of all tumors but its mortality is decreased in the last decades due to the early detection of small masses and to the innovative surgical techniques. The aim of our study was to evaluate safety and feasibility of clampless and sutureless laparoscopic partial nephrectomy (CSLPN) in terms of intra- and postoperative functional results, complication rate and oncological outcome.

METHODS

We evaluated patients undergoing CSLPN between July 2013 and December 2019. Inclusion criteria were single, organ confined tumor with size ≤4 cm, intraparenchymal depth ≤1.5 cm, renal nephrometry score between 4 and 6 and no close contact with the collecting system.

RESULTS

Overall, 62 patients underwent CSLPN. Mean operative time was 105 minutes, mean intraoperative blood loss was 165 mL. Mean drain time and hospital stay were respectively 2.5 and 4.2 days. Mean 24 hours hemoglobin (Hb) decrease was 2.5 g/dL. No significative variations are described in pre- and postoperative renal function. Twelve patients had postoperative complications. At a median follow-up of 38.5 months all the patients are alive and disease free.

CONCLUSIONS

Different techniques have been proposed to reduce warm ischemia time (WIT). In our experience we found many benefits in an off-clamp procedure: it gives an ischemia-related advantage, reduces the overall operating time, eliminates the risks associated with the isolation of hilar vessels. In conclusion CSLPN is a safe and effective procedure for selected renal masses; it does not increase complication rate and offers excellent functional and oncological outcomes.

Hepatic tumors: pitfall in diagnostic imaging

On computed tomography (CT) and magnetic resonance imaging (MRI), hepatocellular tumors are characterized based on typical imaging findings. However, hepatocellular adenoma, focal nodular hyperplasia, and hepatocellular carcinoma can show uncommon appearances at CT and MRI, which may lead to diagnostic challenges. When assessing focal hepatic lesions, radiologists need to be aware of these atypical imaging findings to avoid misdiagnoses that can alter the management plan. The purpose of this review is to illustrate a variety of pitfalls and atypical features of hepatocellular tumors that can lead to misinterpretations providing specific clues to the correct diagnoses. (www.actabiomedica.it)

Robotic partial nephrectomy: The current status

Introduction:

Since its introduction, robotic partial nephrectomy (RPN) has become increasingly popular, in part as a result of several advances in technique. The purpose of this paper is to review these techniques as well as the perioperative, functional, and oncologic outcomes after RPN and compare these outcomes to those after laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN).

Methods:

A literature review was performed to identify papers and meta-analyses that compared outcomes after RPN to OPN or LPN. All meta-analyses were included in this review.

Results:

Technical advances that have contributed to improved outcomes after RPN include the first-assistant sparing technique, the sliding clip technique, early unclamping, and selective arterial clamping. All five meta-analyses that compared LPN to RPN found that RPN was associated with a shorter warm ischemia time (WIT), but that there were no differences in estimated blood loss (EBL) or operative times. Those meta-analyses that compared intraoperative and postoperative complications, conversion to open or radical nephrectomy, length of stay (LOS), and postoperative estimated glomerular filtration rate (eGFR) either found no difference or favored RPN. Four meta-analyses compared RPN to OPN. All four found that EBL, LOS, and postoperative complications favor RPN. There were no significant differences in intraoperative complications, conversion to radical nephrectomy, or positive surgical margin rates. One meta-analysis found that eGFR was better after RPN. Operative time and WIT generally favored OPN.

Conclusions:

Several techniques have been described to improve outcomes after RPN. We believe that the literature shows that RPN is as good if not better than both LPN and OPN and has become the preferred surgical approach.