Impact of Renal Hilar Control on Outcomes of Robotic Partial Nephrectomy: Systematic Review and Cumulative Meta-analysis

Robot-assisted partial nephrectomy of multiple tumors: a multicenter analysis

BACKGROUND

Robot-assisted partial nephrectomy (RAPN) is increasingly performed in challenging tumor constellations like multiple renal masses.

METHODS

The objective was to investigate influencing factors on postoperative renal function (PRF) after ipsilateral robot-assisted partial nephrectomy of multiple tumors (iRAPN-MT). In this retrospective multicenter study, perioperative data of 132 trans- or retroperitoneal iRAPN-MT for ≥ two tumors were analyzed focusing on influencing factors on PRF and acute kidney injury including RIFLE and trifecta criteria. The impact of patient-, surgery- and tumor-related factors was investigated via uni- and multivariate regression analyses.

RESULTS

The majority of patients had two renal masses, with three or more lesions in 19%. Median operative time was 175 minutes. Eighty-five percent of the tumors were dissected on-clamp with a median cumulative warm ischemia time (WITsum) of 15 minutes. Trifecta criteria were fulfilled in 57%. In regression analyses, WITsum, BMI and preoperative eGFR had an impact on eGFR loss before discharge (median -11.6 mL/min). BMI and Charlson Comorbidity Index were independent predictors for the lowest RIFLE stage during hospitalization.

CONCLUSIONS

iRAPN-MT for multiple ipsilateral renal masses is feasible with good trifecta rates. While mostly unmodifiable patient-associated parameters were independent predictors on PRF impairment, WITsum was identified as a surgery-related independent parameter.

Does Preoperative Renal Tumour Biopsy Impact Trifecta Achievement in Partial Nephrectomy?

PURPOSE

We aimed to evaluate the effect of renal tumour biopsy (RTB) on trifecta criteria achievement in patients treated with open partial nephrectomy (OPN).

METHODS

Patients who were diagnosed with renal cancer and underwent OPN between 2012 and 2023 were retrospectively reviewed. The RTB group consisted of patients who underwent RTB before OPN, while the non-RTB group consisted of those who did not undergo RTB. No matching method was employed since parameters such as tumour size and Padua score were comparable between the two groups. The primary outcome was trifecta achievement, defined as negative surgical margins, warm ischemia time (WIT) <25 minutes, and no complications. Secondary outcomes were the clinicopathologic and survival outcomes of both groups.

RESULTS

There were 137 (82.03%) patients in the non-RTB group and 30 (17.96%) patients in the RTB group. The median postoperative follow-up was 45 (24-141) months. The median tumour size was 3.4 (1-7) cm and 3 (1.4-7) cm in the non-RTB group and RTB group, respectively (p=0.282). Seventy-five of the 137 (54.76%) patients in the non-RTB group and 16 of the 30 (53.3%) patients in the RTB group achieved the trifecta criteria (p=0.878). There was no statistically significant difference between the two groups in terms of metastasis-free survival (p=0.332) or overall survival (p=0.359) at 24 months. The rate of intraparenchymal lymphovascular invasion was significantly higher in the RTB group (16.6%) than in the non-RTB group (2.92%) (p=0.013).

CONCLUSIONS

Our study indicated that trifecta achievement rates were comparable between patients who did and those who did not undergo RTB. Consequently, RTB can be safely performed in renal cancer.

Ultrasound-guided renal artery balloon catheter occluded hybrid partial nephrectomy (UBo-HPN) with branch renal artery occlusion: a single arm trial

BACKGROUND

One key focus of partial nephrectomy is preserving renal function. Segmental renal artery occlusion with microdissection at the renal hilum confines ischemia, effectively reducing warm ischemic injury. Ultrasound-Guided Renal Artery Balloon Catheter Occluded Hybrid Partial Nephrectomy (UBo-HPN) can achieve branch occlusion without the need for dissecting the renal hilum.

OBJECTIVE

To investigate the feasibility and safety of UBo-HPN of branch renal artery occlusion in the treatment of localized renal tumors.

SUBJECT AND METHODS

A prospective single-arm analysis involving 20 patients with renal localized tumors underwent robot assisted UBo-HPN with branch renal artery occlusion from August 2021 to July 2023, with an average follow-up of 12 months.

RESULTS

All patient was successfully operated on without conversion to conventional arterial clamping or radical nephrectomy. One case (5%) of minor complication occurred in the whole cohort, which was bruising around the puncture site. The mean total operative time was 95.8 min, with a mean operative time of 21.25 min for vascular intervention. The mean warm ischemia time was 20.35 min, and the median estimated blood loss was 50 ml. The median eGFR preservation percentage at postoperative 48 h, 30 days, and the latest follow-up were 87.52%, 91.47%, and 92.2%, respectively. After a median follow-up of 10.2 (2.3-19.2) months, no patients had radiological tumor recurrence or died from tumor-related causes.

CONCLUSIONS

UBo-HPN with renal artery branch occlusion emerges as an efficient alternative to partial nephrectomy (PN), which achieved branch artery occlusion without dissecting the renal hilum. Long-term follow-up is expected for functional 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.

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.

Off-clamp vs on-clamp robot-assisted partial nephrectomy: a systematic review and meta-analysis

OBJECTIVE

To compare intra- and postoperative outcomes between off-clamp and on-clamp robot-assisted partial nephrectomy (RAPN), using data from randomised controlled trials (RCTs) or covariate-matched studies (propensity score-matched or matched-pair analysis).

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-compliant literature review was conducted on PubMed, EMBASE, Scopus and CENTRAL for relevant studies comparing off-clamp to on-clamp RAPN. Primary outcomes were estimated blood loss, postoperative percentage decrease in estimated glomerular filtration rate (eGFR), and margin positive rate. Secondary outcomes were operative time, postoperative eGFR, length of stay, all postoperative complications, major complications, and need for transfusion. Random-effects meta-analyses were performed to generate mean differences (MDs) or odds ratios (ORs).

RESULTS

A total of 10 studies (2307 patients) were shortlisted for analysis. There was no significant difference in estimated operative blood loss between off-clamp and on-clamp RAPN (MD 21.9 mL, 95% confidence interval [CI] -0.9 to 44.7 mL; P = 0.06, I2  = 58%). Off-clamp RAPN yielded a smaller postoperative eGFR deterioration (MD 3.10%, 95% CI 1.05-5.16%; P = 0.008, I2  = 13%) and lower odds of margin positivity (OR 0.62, 95% CI 0.40-0.94; P = 0.03, I2  = 0%). No significant differences were found for all secondary outcomes.

CONCLUSIONS

Off-clamp and on-clamp RAPN are similarly effective approaches for selected renal masses. Within the classic trifecta of PN outcomes, off-clamp RAPN yields similar rates of perioperative complications and may possibly offer better preservation of renal function and reduced margin-positive rates.

Indocyanine green-marked fluorescence-guided off-clamp versus intraoperative ultrasound-guided on-clamp robotic partial nephrectomy: Outcomes on surgical procedure

Objectives

To compare surgical and functional outcomes between off-clamp robot-assisted partial nephrectomy with indocyanine-green tumour marking through preliminary superselective embolization and on-clamp robot-assisted partial nephrectomy with intraoperative ultrasound identification of the renal mass.

Material and methods

One hundred and forty patients with a single renal mass underwent indocyanine-green fluorescence-guided off-clamp robot-assisted partial nephrectomy with preoperative superselective embolization (Group A, 70 patients) versus intraoperative ultrasound-guided on-clamp robot-assisted partial nephrectomy without embolization (Group B, 70 patients). We assessed operative time, intraoperative blood loss, complications, length of stay, renal function, need for ancillary procedures and blood transfusions.

Results

Mean tumour size was 24 versus 25 mm in Group A versus Group B (p = 0.19). Mean operative time was 86.5 versus 121.8 min (p = 0.02), mean blood loss was 72.8 versus 214.2 mL (p = 0.02), and mean haemoglobin drop on postoperative day 1 was 1.1 versus 2.6 g/dL (p = 0.04) in Group A versus Group B. One-month creatinine, hospital stay and enucleated tumour volume were comparable. Ten postoperative complications occurred in Group A (13.3%) and 11 in Group B (15.3%). Following superselective embolization, no patients required blood transfusions versus two patients in Group B. Postoperative selective renal embolization was needed in one case per group.

Conclusions

Preoperative superselective embolization of a renal mass with indocyanine-green before off-clamp robot-assisted partial nephrectomy significantly reduces operative time and intraoperative blood loss compared to on-clamp intraoperative ultrasound-guided robot-assisted partial nephrectomy. A longer follow-up is needed to establish the effect on renal function.

Development and internal validation of a nomogram predicting 3-year chronic kidney disease upstaging following robot-assisted partial nephrectomy

PURPOSE

Aim of the present study was to develop and validate a nomogram to accurately predict the risk of chronic kidney disease (CKD) upstaging at 3 years in patients undergoing robot-assisted partial nephrectomy (RAPN).

METHODS

A multi-institutional database was queried to identify patients treated with RAPN for localized renal tumor (cT1-cT2, cN0, cM0). Significant CKD upstaging (sCKD-upstaging) was defined as development of newly onset CKD stage 3a, 3b, and 4/5. Model accuracy was calculated according to Harrell C-index. Subsequently, internal validation using bootstrapping and calibration was performed. Then nomogram was depicted to graphically calculate the 3-year sCKD-upstaging risk. Finally, regression tree analysis identified potential cut-offs in nomogram-derived probability. Based on this cut-off, four risk classes were derived with Kaplan-Meier analysis tested this classification.

RESULTS

Overall, 965 patients were identified. At Kaplan-Meier analysis, 3-year sCKD-upstaging rate was 21.4%. The model included baseline (estimated glomerular filtration rate) eGFR, solitary kidney status, multiple lesions, R.E.N.A.L. nephrometry score, clamping technique, and postoperative acute kidney injury (AKI). The model accurately predicted 3-year sCKD-upstaging (C-index 84%). Based on identified nomogram cut-offs (7 vs 16 vs 26%), a statistically significant increase in sCKD-upstaging rates between low vs intermediate favorable vs intermediate unfavorable vs high-risk patients (1.3 vs 9.2 vs 22 vs 54.2%, respectively, p < 0.001) was observed.

CONCLUSION

Herein we introduce a novel nomogram that can accurately predict the risk of sCKD-upstaging at 3 years. Based on this nomogram, it is possible to identify four risk categories. If externally validated, this nomogram may represent a useful tool to improve patient counseling and management.

Outcomes and Techniques of Robotic-Assisted Partial Nephrectomy (RAPN) for Renal Hilar Masses: A Comprehensive Systematic Review

Background: Robot-assisted partial nephrectomy (RAPN) is increasingly being employed in the management of renal cell carcinoma (RCC) and it is expanding in the field of complex renal tumors. The aim of this systematic review was to consolidate and assess the results of RAPN when dealing with entirely central hilar masses and to examine the various methods used to address the surgical difficulties associated with them. Methods: A thorough literature search in September 2023 across various databases focused on RAPN for renal hilar masses, adhering to PRISMA guidelines. The primary goal was to evaluate RAPN's surgical and functional outcomes, with a secondary aim of examining different surgical techniques. Out of 1250 records, 13 full-text manuscripts were reviewed. Results: Evidence is growing in favor of RAPN for renal hilar masses. Despite a predominance of retrospective studies and a lack of long-term data, RAPN shows positive surgical outcomes and preserves renal function without compromising cancer treatment effectiveness. Innovative suturing and clamping methods are emerging in surgical management. Conclusions: RAPN is a promising technique for managing renal hilar masses in RCC, offering effective surgical outcomes and renal function preservation. The study highlights the need for more long-term data and prospective studies to further validate these findings.

The safety and effectiveness of laparoscopic off-clamp tumor evacuation versus traditional nephron-sparing surgery for large (>4 cm) sporadic renal angiomyolipomas

BACKGROUND

Off-clamp nephron-sparing surgery (NSS) have been selectively performed in renal tumors in which the majority are T1a (<4 cm) renal caners. Less is known, however, whether off-clamp is a safe and effective option for treatment of Sporadic Renal Angiomyolipomas (RAML), especially in those >4 cm. The objective of our study was to compare the perioperative and renal function outcomes of a novel off-clamp tumor evacuation technique versus conventional laparoscopic NSS for the treatment of large sporadic RAMLs (>4 cm).

METHODS

From January 2021 to June 2022, 42 patients diagnosed with RAML were prospectively randomized to receive laparoscopic standard NSS (Group 1) and off-clamp tumor evacuation (Group 2). The surgical and postoperative outcomes of both groups were compared.

RESULTS

Baseline characteristics demonstrated no discernible variation between Group 1 and Group 2. Compared to Group 1, Group 2 was associated shorter operative time (92.5 vs 82.3 min, p < 0.001), elimination of warm ischemic time (22.9 vs 0 min, p < 0.001), more blood loss (92.6 vs 161.9 ml, p = 0.02), and lower short-term renal function reduction of the operated kidney (17.2% vs 9%; p < 0.001). Neither major complication nor recurrence occurred.

CONCLUSION

It seems that transperitoneal laparoscopic off-clamp tumor evacuation is a feasible and safe option for the treatment of RAML, with the added benefit of preserving renal function to a greater extent than the traditional methods.

Holographic 3D renal segments reconstruction protects renal function by promote choice of selective renal artery clamping during robot-assisted partial nephrectomy

OBJECTIVE

To investigate the impact of selective artery clamping (SAC) and main artery clamping (MAC) during robot-assisted partial nephrectomy (RAPN) on renal function and the influence of holographic three-dimensional (3D) reconstruction of renal segments on the selection between SAC and MAC.

METHODS

This retrospective observational study included patients who underwent RAPN at First Hospital Affiliated to the Army Medical University between December 2016 and July 2022. According to the clamping methods, the patients were divided into the SAC group and the MAC group. The primary outcome was renal function.

RESULTS

A total of 422 patients (194 in the SAC group and 228 in the MAC group) were included. The RAPN procedures were all completed successfully. The patients in SAC group had less glomerular filtration rate (GFR) decline in the affected kidney (8.6 ± 7.0 ml/min vs. 18.7 ± 10.9 ml/min, P < 0.001) and minor estimated glomerular filtration rate (eGFR) decrease (4.3 ± 10.5 ml/min vs. 12.6 ± 12.1 ml/min, P < 0.001) than those in MAC group. Among 37 patients with baseline renal insufficiency, the GFR decline of the affected kidney in the SAC subgroup was significantly lower than in the MAC subgroup (5.5 ± 6.5 ml/min vs. 14.3 ± 9.2 ml/min, P = 0.002). The proportion of patients who underwent 3D reconstruction was significant higher in the SAC group than in the MAC group. (65.46% vs. 28.07%, P < 0.001).

CONCLUSION

The SAC technique during RAPN may serve as a protective measure for renal function, while the implementation of holographic 3D renal segment reconstruction technique may facilitate optimal selection of SAC.

Can the Abdominal Aortic Atherosclerotic Plaque Index Predict Functional Outcomes after Robot-Assisted Partial Nephrectomy?

This study aims to evaluate the abdominal aortic atherosclerotic plaque index (API)'s predictive role in patients with pre-operatively or post-operatively developed chronic kidney disease (CKD) treated with robot-assisted partial nephrectomy (RAPN) for renal cell carcinoma (RCC). One hundred and eighty-three patients (134 with no pre- and post-operative CKD (no CKD) and 49 with persistent or post-operative CKD development (post-op CKD)) who underwent RAPN between January 2019 and January 2022 were deemed eligible for the analysis. The API was calculated using dedicated software by assessing the ratio between the CT scan atherosclerotic plaque volume and the abdominal aortic volume. The ROC regression model demonstrated the influence of API on CKD development, with an increasing effect according to its value (coefficient 0.13; 95% CI 0.04-0.23; p = 0.006). The Model 1 multivariable analysis of the predictors of post-op CKD found that the following are independently associated with post-op CKD: Charlson Comorbidity Index (OR 1.31; p = 0.01), last follow-up (FU) Δ%eGFR (OR 0.95; p < 0.01), and API ≥ 10 (OR 25.4; p = 0.01). Model 2 showed API ≥ 10 as the only factor associated with CKD development (OR 25.2; p = 0.04). The median follow-up was 22 months. Our results demonstrate API to be a strong predictor of post-operative CKD, allowing the surgeon to tailor the best treatment for each patient, especially in those who might be at higher risk of CKD.

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.

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.

Functional recovery after partial nephrectomy: next generation analysis

OBJECTIVES

To provide a more rigorous assessment of factors affecting functional recovery after partial nephrectomy (PN) using novel tools that allow for analysis of more patients and improved accuracy for assessment of parenchymal volume loss, thereby revealing the potential impact of secondary factors such as ischaemia.

PATIENTS AND METHODS

Of 1140 patients managed with PN (2012-2014), 670 (59%) had imaging and serum creatinine levels measured before and after PN necessary for inclusion. Recovery from ischaemia was defined as the ipsilateral glomerular filtration rate (GFR) saved normalised by parenchymal volume saved. Acute kidney injury was assessed through Spectrum Score, which quantifies the degree of acute ipsilateral renal dysfunction due to exposure to ischaemia that would otherwise be masked by the contralateral kidney. Multivariable regression was used to identify predictors of Spectrum Score and Recovery from Ischaemia.

RESULTS

In all, 409/189/72 patients had warm/cold/zero ischaemia, respectively, with median (interquartile range [IQR]) ischaemia times for cold and warm ischaemia of 30 (25-42) and 22 (18-28) min, respectively. The median (IQR) global preoperative GFR and new baseline GFR (NBGFR) were 78 (63-92) and 69 (54-81) mL/min/1.73 m2 , respectively. The median (IQR) ipsilateral preoperative GFR and NBGFR were 40 (33-47) and 31 (24-38) mL/min/1.73 m2 , respectively. Functional recovery correlated strongly with parenchymal volume preserved (r = 0.83, P < 0.01). The median (IQR) decline in ipsilateral GFR associated with PN was 7.8 (4.5-12) mL/min/1.73 m2 with loss of parenchyma accounting for 81% of this loss. The median (IQR) recovery from ischaemia was similar across the cold/warm/zero ischaemia groups at 96% (90%-102%), 95% (89%-101%), and 97% (91%-102%), respectively. Independent predictors of Spectrum Score were ischaemia time, tumour complexity, and preoperative global GFR. Independent predictors of recovery from ischaemia were insulin-dependent diabetes mellitus, refractory hypertension, warm ischaemia, and Spectrum Score.

CONCLUSIONS

The main determinant of functional recovery after PN is parenchymal volume preservation. A more robust and rigorous evaluation allowed us to identify secondary factors including comorbidities, increased tumour complexity, and ischaemia-related factors that are also independently associated with impaired recovery, although altogether these were much less impactful.

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

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

The role of warm ischemia time on functional outcomes after robotic partial nephrectomy: a radionuclide renal scan study from the clock randomized trial

PURPOSE

To evaluate the relationship between warm ischemia time (WIT) duration and renal function after robot-assisted partial nephrectomy (RAPN).

METHODS

The CLOCK trial is a phase 3 randomized controlled trial comparing on- vs off-clamp RAPN. All patients underwent pre- and postoperative renal scintigraphy. Six-month absolute variation of eGFR (AV-GFR), rate of relative variation in eGFR over 25% (RV-GFR > 25), absolute variation of split renal function (SRF) at scintigraphy (AV-SRF). The relationships WIT/outcomes were assessed by correlation graphs and then modeled by uni- and multivariable regression.

RESULTS

324 patients were included (206 on-clamp, 118 off-clamp RAPN). Correlation graphs showed a threshold on WIT equal to 10 min. The differences in outcome measures between cases with WIT < vs ≥ 10 min were: AV-GFR - 3.7 vs - 7.5 ml/min (p < 0.001); AV-SRF - 1% vs - 3.6% (p < 0.001); RV-GFR > 25 9.3% vs 17.8% (p = 0.008). Multivariable models found that AV-GFR was related to WIT ≥ 10 min (regression coefficient [RC] - 0.52, p = 0.019), age (RC - 0.35, p = 0.001) and baseline eGFR (RC - 0.30, p < 0.001); RV-GFR > 25 to WIT ≥ 10 min (odds ratio [OR] 1.11, p = 0.007) and acute kidney injury defined as > 50% increase in serum creatinine (OR 19.7, p = 0.009); AV-SRF to WIT ≥ 10 min (RC - 0.30, p = 0.018), baseline SRF (RC - 0.76, p < 0.001) and RENAL score (RC - 0.60. p = 0.028). The main limitation was that the CLOCK trial was designed on a different endpoint and therefore the present analysis could be underpowered.

CONCLUSIONS

Up to 10 min WIT had no consequences on functional outcomes. Above the 10-min threshold, a statistically significant, but clinically negligible impact was found.

Single-cell transcription analysis reveals the tumor origin and heterogeneity of human bilateral renal clear cell carcinoma

Bilateral renal clear cell carcinoma (BRCC) is a rare type of renal cell carcinoma (RCC) that accounts for only 1-5% of RCC cases and has a poor clinical prognosis. The origin, tumor microenvironment, cellular molecular features, and intra-tumoral heterogeneity of BRCC are still unclear. We downloaded BRCC single-cell transcriptome sequencing data from the gene expression omnibus database biochip GSE171306, containing 3,575 cells from left-sided clear cell renal cell carcinoma (ccRCC) and 3,568 cells from right-sided ccRCC, and used a series of R packages for data quality control (QC) and subsequent analysis of BRCC single-cell transcriptome data, including the use of the R packages Seurat and scCancer for cell QC, identification of major cell types, and cell annotation; R package scran for calculation of cell cycle scores; R package infercnv for malignancy scoring of tumor cells; R package ReactomeGSA for functional enrichment analysis; R package Monocle 2 for the analysis of cell differentiation trajectories; and R package CellphoneDB for the analysis of intercellular interactions. In this study, by analyzing the high-quality single-cell transcriptome data of BRCC, we identified 18 cell types and found that left- and right-sided ccRCC were approximately the same in terms of cell type and the number of each cell but differed significantly in terms of tumor cell malignancy score, tumor microenvironment, and cell stemness score. In the cell differentiation trajectory analysis of BRCC, we found that endothelial cells and macrophages play an extremely important role in its tumor progression. Further cell communication analysis was performed, and we found that it may signal through ligand-receptors, such as vascular endothelial growth factor-vascular endothelial growth factor receptor1 (VEGF-VEGFR1), MIF-(CD74-CXCR4), and growth arrest-specific protein 6-AXL, to influence the development of BRCC. The analysis of single-cell transcriptomic data of human BRCC suggests that left- and right-sided ccRCC may be of the same tumor origin, but the left-sided ccRCC is more malignant and has a better immune response.

Partial nephrectomy in solitary kidneys: comparison between open surgery and robotic-assisted laparoscopy on perioperative and functional outcomes (UroCCR-54 study)

PURPOSE

The management of solitary kidney tumors is a surgical challenge, requiring irreproachable results on both oncological and functional outcomes. The goal of our study was to compare the perioperative results of robotic-assisted partial nephrectomy (RAPN) to open surgery in this indication.

METHODS

We led a multicentric study based on the prospectively maintained French national database UroCCR. Patients who underwent partial nephrectomy on a solitary kidney between 1988 and 2020 were included. Clinical and pathological data were retrospectively analyzed. The main outcome of the study was the analysis of the variation of the estimated glomerular filtration rate (eGFR) calculated according to MDRD at 3, 6, 12, and 24 months depending on the chosen surgical approach. The secondary outcomes were the comparison of Trifecta success, perioperative complications, and length of hospital stay.

RESULTS

In total, 150 patients were included; 68 (45%) in the RAPN group and 82 (55%) in the open surgery group. The two groups were comparable for all data. The variation of eGFR at 3, 6, 12, or 24 months was comparable without any significant difference between the 2 groups (p = 0.45). Trifecta was achieved in 40% of the patients in the RAPN group and 33% in the open group (p = 0.42). A significant difference was observed for the length of stay, 5 days for the robot group versus 9 days for the open surgery group (p < 0.0001).

CONCLUSION

In our study, the surgical approach did not modify functional results and we noted a significant decrease in hospital stay and complications in the RAPN group. RAPN is a safe and efficient method for management of kidney tumors in solitary kidneys.

A Novel Three-dimensional Planning Tool for Selective Clamping During Partial Nephrectomy: Validation of a Perfusion Zone Algorithm

BACKGROUND

Selective clamping during robot-assisted partial nephrectomy (RAPN) requires extensive knowledge on patient-specific renal vasculature, obtained through imaging.

OBJECTIVE

To validate an in-house developed perfusion zone algorithm that provides patient-specific three-dimensional (3D) renal perfusion information.

DESIGN, SETTING, AND PARTICIPANTS

Between October 2020 and June 2022, 25 patients undergoing RAPN at Ghent University Hospital were included. Three-dimensional models, based on preoperative computed tomography (CT) scans, showed the clamped artery's ischemic zone, as calculated by the algorithm.

SURGICAL PROCEDURE

All patients underwent selective clamping during RAPN. Indocyanine green (ICG) was administered to visualize the true ischemic zone perioperatively. Surgery was recorded for a postoperative analysis.

MEASUREMENTS

The true ischemic zone of the clamped artery was compared with the ischemic zone predicted by the algorithm through two metrics: (1) total ischemic zone overlap and (2) tumor ischemic zone overlap. Six urologists assessed metric 1; metric 2 was assessed objectively by the authors.

RESULTS AND LIMITATIONS

In 92% of the cases, the algorithm was sufficiently accurate to plan a selective clamping strategy. Metric 1 showed an average score of 4.28 out of 5. Metric 2 showed an average score of 4.14 out of 5. A first limitation is that ICG can be evaluated only at the kidney surface. A second limitation is that mainly patients with impaired renal function are expected to benefit from this technology, but contrast-enhanced CT is required at present.

CONCLUSIONS

The proposed new tool demonstrated high accuracy when planning selective clamping for RAPN. A follow-up prospective study is needed to determine the tool's clinical added value.

PATIENT SUMMARY

In partial nephrectomy, the surgeon has no information on which specific arterial branches perfuse the kidney tumor. We developed a surgeon support system that visualizes the perfusion zones of all arteries on a three-dimensional model and indicates the correct arteries to clamp. In this study, we validate this tool.

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?

Evaluation of oncological outcomes of robotic partial nephrectomy according to the type of hilar control approach (On-clamp vs Off-clamp), a multicentric study of the French network of research on kidney cancer-UROCCR 58-NCT03293563

PURPOSE

To compare off-clamp vs on-clamp robotic partial nephrectomy (RPN) for renal cell carcinoma (RCC) in terms of oncological outcomes, and to assess the impact of surgical experience (SE).

METHODS

We extracted data of a contemporary cohort of 1359 patients from the prospectively maintained database of the French national network of research on kidney cancer (UROCCR). The primary objective was to assess the positive surgical margin (PSM) rate. We also evaluated the oncological outcomes regardless of the surgical experience (SE) by dividing patients into three groups of SE as a secondary endpoints. SE was defined by the caseload of RPN per surgeon per year. For the continuous variables, we used Mann-Whitney and Student tests. We assessed survival analysis according to hilar control approach by Kaplan-Meier curves with log rank tests. A logistic regression multivariate analysis was used to evaluate the independent factors of PSM.

RESULTS

Outcomes of 224 off-clamp RPN for RCC were compared to 1135 on-clamp RPN. PSM rate was not statistically different, with 5.6% in the off-clamp group, and 11% in the on-clamp group (p = 0.1). When assessing survival analysis for overall survival (OS), local recurrence-free survival (LR), and metastasis-free survival (MFS) according to hilar clamping approach, there were no statistically significant differences between the two groups with p value log rank = 0.2, 0.8, 0.1, respectively. In multivariate analysis assessing SE, hilar control approach, hospital volume (HV), RENAL score, gender, Age, ECOG, EBL, BMI, and indication of NSS, age at surgery was associated with PSM (odds ratio [OR] 1.03 (95% CI 1.00-1.04), 0.02), whereas SE, HV, and type of hilar control approach were not predictive factors of PSM.

CONCLUSION

Hilar control approach seems to have no impact on PSM of RPN for RCC. Our findings were consistent with randomized trials.

Superior Mesenteric Artery Injury during Robotic Radical Nephrectomy: Scenarios and Management Strategies

Injury to the superior mesenteric artery (SMA) is a rare, underreported, and potentially devastating complication. This study aims to propose a systematic workup to describe how to prevent and manage SMA injury in a standardized stepwise manner. Three different instances of intraoperative injury to the SMA are described in an accompanying video. All three occurred when the SMA was misidentified as the left renal artery during left robotic radical nephrectomy. In the first case, the SMA was mistakenly identified as the renal artery, but after further dissection, the real renal artery was identified and SMA injury was prevented. In the second case, the SMA was clipped and the real left renal artery was subsequently identified, requiring clip removal. In the third case, the SMA was clipped and completely transected, requiring prompt repair by vascular surgery with a successful outcome. This study aims to propose a systematic workup to describe how to prevent and manage SMA injury in a standardized stepwise manner. The proper anatomic recognition of the SMA may prevent its injury. Intraoperative SMA injury should be promptly identified and repaired to avoid its devastating consequences.

The Intraoperative Complications Assessment and Reporting with Universal Standards (ICARUS) Global Surgical Collaboration Project: Development of Criteria for Reporting Adverse Events During Surgical Procedures and Evaluating Their Impact on the Postoperative Course

BACKGROUND

Intraoperative adverse events (iAEs) are surgical and anesthesiologic complications. Despite the availability of grading criteria, iAEs are infrequently reported in the surgical literature and in cases for which iAEs are reported, these events are described with significant heterogeneity.

OBJECTIVE

To develop Intraoperative Complications Assessment and Reporting with Universal Standards (ICARUS) Global Surgical Collaboration criteria to standardize the assessment, reporting, and grading of iAEs. The ultimate aim is to improve our understanding of the nature and frequency of iAEs and our ability to counsel patients regarding surgical procedures.

DESIGN, SETTING, AND PARTICIPANTS

The present study involved the following steps: (1) collecting criteria for assessing, reporting, and grading of iAEs via a comprehensive umbrella review; (2) collecting additional criteria via a survey of a panel of experienced surgeons (first round of a modified Delphi survey); (3) creating a comprehensive list of reporting criteria; (4) combining criteria acquired in the first two steps; and (5) establishing a consensus on clinical and quality assessment utility as determined in the second round of the Delphi survey.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Panel inter-rater agreement and consistency were assessed as the overall percentage agreement and Cronbach's α.

RESULTS AND LIMITATIONS

The umbrella review led to nine common criteria for assessing, grading, and reporting iAEs, and review of iAE grading systems led to two additional criteria. In the first Delphi round, 35 surgeons responded and two criteria were added. In the second Delphi round, 13 common criteria met the threshold for final guideline inclusion. All 13 criteria achieved the consensus minimum of 70%, with agreement on the usefulness of the criteria for clinical and quality improvement ranging from 74% to 100%. The mean inter-rater agreement was 89.0% for clinical improvement and 88.6% for quality improvement.

CONCLUSIONS

The ICARUS Global Collaboration criteria might aid in identifying important criteria when reporting iAEs, which will support all those involved in patient care and scientific publishing.

PATIENT SUMMARY

We consulted a panel of experienced surgeons to develop a set of guidelines for academic surgeons to follow when publishing surgical studies. The surgeon panel proposed a list of 13 criteria that may improve global understanding of complications during specific procedures and thus improve the ability to counsel patients on surgical risk.

On-Clamp vs. Off-Clamp Robot-Assisted Partial Nephrectomy for cT2 Renal Tumors: Retrospective Propensity-Score-Matched Multicenter Outcome Analysis

We compared perioperative outcomes after on-clamp versus off-clamp robot-assisted partial nephrectomy (RAPN) for >7 cm renal masses. A multicenter dataset was queried for patients who had undergone RAPN for a cT2cN0cM0 kidney tumor from July 2007 to February 2022. The Trifecta achievement (negative surgical margins, no severe complications, and ≤ 30% postoperative estimated glomerular filtration rate (eGFR) reduction) was considered a surrogate of surgical quality. Overall, 316 cases were included in the analysis, and 58% achieved the Trifecta. A propensity-score-matched analysis generated two cohorts of 89 patients homogeneous for age, ASA score, preoperative eGFR, and RENAL score (all p > 0.21). Compared to the on-clamp approach, OT was significantly shorter in the off-clamp group (80 vs. 190 min; p < 0.001), the incidence of sRFD was lower (22% vs. 40%; p = 0.01), and the Trifecta rate higher (66% vs. 46%; p = 0.01). In a crude analysis, >20 min of hilar clamping was associated with a significantly higher risk of sRFD (OR: 2.30; 95%CI: 1.13−4.64; p = 0.02) and with reduced probabilities of achieving the Trifecta (OR: 0.46; 95%CI: 0.27−0.79; p = 0.004). Purely off-clamp RAPN seems to be a safe and viable option to treat cT2 renal masses and may outperform the on-clamp approach regarding perioperative surgical outcomes.

Application and clinical efficacy of modified early unclamping technique in robot-assisted laparoscopic partial nephrectomy

OBJECTIVE

To investigate the clinical safety and efficacy of a modified early unclamping technique in robot-assisted laparoscopic partial nephrectomy (RAPN).

METHODS

The clinical data of 38 patients with renal tumors who underwent the modified early unclamping technique in RAPN surgery admitted to the Department of Urology, the Third People's Hospital of Hangzhou and the First Affiliated Hospital of Nanchang University from January 2018 to April 2021 were retrospectively analyzed. The control group consisted of 78 patients with renal tumors who underwent standard clamping during the RAPN surgery completed by the same surgeon during the same period. The perioperative-related indicators and postoperative renal function recovery were analyzed and compared between the two groups.

RESULTS

All patients (n = 116) finished the RAPN successfully, and none were transferred to radical or open surgery in either group. The warm ischemia time in the modified early unclamping group was significantly lower than that in the standard clamping group (P < 0.001). After surgery, the renal function index at each time point in the modified early unclamping group was higher than that in the standard clamping group; renal function gradually returned to near preoperative levels after 3 months in both groups. Postoperative follow-up showed no tumor recurrence or metastasis.

CONCLUSION

The application of a modified early unclamping technique in RAPN surgery is safe and feasible. Compared with standard clamping, modified early unclamping can significantly shorten the warm ischemia time of kidneys without increasing the volume of intraoperative blood loss and complications, which helps to protect the postoperative renal function of patients.

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

Objective

Methods

Results

Conclusion

New imaging technologies for robotic kidney cancer surgery

Objective

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

Methods

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

Results

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

Conclusion

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

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.

Utilizing head-mounted eye trackers to analyze patterns and decision-making strategies of 3D virtual modelling platform (IRIS™) during preoperative planning for renal cancer surgeries

PURPOSE

IRIS^™ provides interactive, 3D anatomical visualizations of renal anatomy for pre-operative planning that can be manipulated by altering transparency, rotating, zooming, panning, and overlaying the CT scan. Our objective was to analyze how eye tracking metrics and utilization patterns differ between preoperative surgical planning of renal masses using IRIS and CT scans.

METHODS

Seven surgeons randomly reviewed IRIS and CT images of 9 patients with renal masses [5 high complexity (RENAL score ≥ 8), 4 low complexity (≤ 7)]. Surgeons answered a series of questions regarding patient anatomy, perceived difficulty (/100), confidence (/100), and surgical plan. Eye tracking metrics (mean pupil diameter, number of fixations, and gaze duration) were collected.

RESULTS

Surgeons spent significantly less time interpreting data from IRIS than CT scans (- 67.1 s, p < 0.01) and had higher inter-rater agreement of surgical approach after viewing IRIS (α = 0.16-0.34). After viewing IRIS, surgical plans although not statistically significant demonstrated a greater tendency towards a more selective ischemia approaches which positively correlated with improved identification of vascular anatomy. Planned surgical approach changed in 22/59 of the cases. Compared to viewing the CT scan, left and right mean pupil diameter and number/duration of fixations were significantly lower when using IRIS (p < 0.01, p < 0.01, p = 0.42, p < 0.01, respectively), indicating interpreting information from IRIS required less mental effort despite under-utilizing its interactive features.

CONCLUSIONS

Surgeons extrapolated more detailed information in less time with less mental effort using IRIS than CT scans and proposed surgical approaches with potential to enhanced surgical outcomes.

Tumor volume and tumor crossing of the axial renal midline predict renal function after robotic partial nephrectomy

There are several nephrometry scoring systems for predicting surgical complexity and potential perioperative morbidity. The R.E.N.A.L. scoring system, one of the most well-known nephrometry scoring systems, emphasizes the features on which it is based (Radius, Exophytic/endophytic, Nearness to collecting system or sinus, Anterior/posterior, and Location relative to polar lines). The ability of these nephrometry scoring systems to predict loss of renal function after robotic partial nephrectomy (RPN) remains controversial. Therefore, we verified which combination of factors from nephrometry scoring systems, including tumor volume, was the most significant predictor of postoperative renal function. Patients who underwent RPN for cT1 renal tumors in our hospital were reviewed retrospectively (n = 163). The preoperative clinical data (estimated glomerular filtration rate [eGFR], comorbidities, and nephrometry scoring systems including R.E.N.A.L.) and perioperative outcomes were evaluated. We also calculated the tumor volume using the equation applied to an ellipsoid by three-dimensional computed tomography. The primary outcome was reduced eGFR, which was defined as an eGFR reduction of ≥ 20% from baseline to 6 months after RPN. Multivariable logistic regression analyses were used to evaluate the relationships between preoperative variables and reduced eGFR. Of 163 patients, 24 (14.7%) had reduced eGFR. Multivariable analyses indicated that tumor volume (cutoff value ≥ 14.11 cm³, indicating a sphere with a diameter ≥ approximately 3 cm) and tumor crossing of the axial renal midline were independent factors associated with a reduced eGFR (odds ratio [OR] 4.57; 95% confidence interval [CI] 1.69-12.30; P = 0.003 and OR 3.50; 95% CI 1.30-9.46; P = 0.034, respectively). Our classification system using these two factors showed a higher area under the receiver operating characteristic curve (AUC) than previous nephrometry scoring systems (AUC = 0.786 vs. 0.653-0.719), and it may provide preoperative information for counseling patients about renal function after RPN.

ROBOCOP II (ROBOtic assisted versus conventional open partial nephrectomy) randomised, controlled feasibility trial: clinical trial protocol

INTRODUCTION

Randomised controlled trials comparing robotic-assisted partial nephrectomy (RAPN) and open PN (OPN) are lacking. Therefore, we aim to report the study protocol and a trial update for a randomised controlled feasibility trial comparing RAPN versus OPN for renal neoplasms.

METHODS AND ANALYSIS

The ROBOtic assisted versus conventional Open Partial nephrectomy II trial is designed as a single-centre, randomised, open-label, feasibility trial. Participation will be offered to patients with renal neoplasms and deemed feasible for both, OPN and RAPN. We aim to enrol 50 patients within 15 months using a 1:1 allocation ratio. The primary endpoint of the trial is feasibility of recruitment and will be successful if one third of eligible patients agree to participate. Secondary endpoints include perioperative results, health-related quality of life, inflammatory response as well as surgical ergonomics of the operating team. If the primary outcome, feasibility of recruitment, is successful, the secondary results of the trial will be used for planning a confirmative phase III trial.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the local institutional review board (Ethik-Kommission II at Heidelberg University: 2020-542N). Results will be made publicly available in peer-reviewed scientific journals and presented at appropriate congresses and social media.

TRIAL REGISTRATION NUMBER

NCT04534998.

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.

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

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

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.

Superselective Ischemia in Robotic Partial Nephrectomy Does Not Provide Better Long-term Renal Function than Renal Artery Clamping in a Randomized Controlled Trial (EMERALD): Should We Take the Risk?

BACKGROUND

Superselective clamping of tumor-targeted arteries aims to eliminate ischemia of the remnant kidney while keeping tumor bed bloodless during excision.

OBJECTIVE

To evaluate the impact of superselective clamping on long-term renal function, compared with renal artery early unclamping.

DESIGN, SETTING, AND PARTICIPANTS

A randomized monocentric single-blind trial (1:1) was conducted from February 2018 to August 2019. Patients with a single renal tumor were candidates for a robot-assisted partial nephrectomy (RAPN) in a referral center. EMERALD (NCT03679572) was powered to include 50 patients with an interim analysis after 30 cases.

INTERVENTION

Superselective RAPN (SS-RAPN) with near-infrared fluorescence (NIRF) or conventional RAPN with renal artery early unclamping.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was the percent change of estimated glomerular filtration rate (eGFR) in the operated kidney after 6 mo (combination of eGFR and relative function on ^99mTc-DMSA scintigraphy). Secondary endpoints assessed feasibility and safety of the technique.

RESULTS AND LIMITATIONS

Relative eGFR reduction in the operated kidney at 6 mo did not differ significantly (-21.4% vs -23.4%, p=0.66). This absence of difference remained after adjusting on percentage of kidney volume preserved, which was an independent predictor of functional preservation. There were no significant differences in terms of blood loss, change in hemoglobin, postoperative complications, transfusion, and conversion to radical nephrectomy (two vs zero) or to open surgery (one vs zero). Despite a good accrual, the steering committee interrupted the trial after the interim analysis for futility given the absence of trend in favor of SS-RAPN.

CONCLUSIONS

SS-RAPN using NIRF does not provide better renal function preservation than renal artery clamping, questioning the interest of this technique at a higher risk of bleeding.

PATIENT SUMMARY

In this randomized controlled trial, superselective clamping of tumor feeding arteries did not show any advantage in terms of long-term renal function compared with conventional artery clamping.

Renal Function: Implications on the Surgical Treatment of RCC

The good oncologic results after partial nephrectomy for stage 1 RCC show that radical nephrectomy is an overtreatment in most cases, and that many healthy nephrons are removed unnecessarily. However, partial nephrectomy is a difficult operation, with increased blood loss and a higher risk of complications. Therefore, the advantage of preserved function has to be weighed up against the increased trauma of surgery in each individual patient, and the assessment of preoperative function may influence this decision, among other factors such as comorbidities and age. In most studies, renal function has been assessed by means of estimated glomerular filtration rate, and this parameter is very helpful for long-term studies in large populations. However, more precise measurement based on clearance studies are sometimes required for more sophisticated investigations. The technique of partial nephrectomy has evolved substantially in recent years, resulting in the preservation of more nephrons, less damage to the remaining parenchyma, less blood loss, and a decreased risk of complications. The introduction of minimally invasive surgery for this purpose has also decreased the overall morbidity of surgery. In the long-term, chronic kidney disease may result in increased cardiac mortality. There is ongoing discussion on this problem, however, this potential negative influence on overall survival is not only influenced by the rate of renal insufficiency, but also to a great extent by other comorbidities such as hypertension and diabetes. Therefore, in addition to providing the best surgery for any given patient, we have to make sure that the treatment of the comorbidities will also be part of our patient management, since the risk of cardiac failure may be greater than the risk of poor oncologic outcome.

Consulting 'Dr. Google' for minimally invasive urological oncological surgeries: A contemporary web-based trend analysis

PURPOSE

To determine web-based public interest in minimally invasive surgery (MIS) specifically for urological oncological surgical procedures and how interest in robotics and laparoscopy compares over time.

MATERIALS AND METHODS

Worldwide search-engine trend analysis included electronic Google queries of MIS urologic options from January 2004 to August 2019, worldwide. Join-point regression was performed. Comparison of annual relative search volume (ARSV) and average annual percentage change (AAPC) were analysed to assess loss or gain of interest. Evaluations were made regarding 1) penetrance of interest for MIS in Urology; 2) how MIS urologic procedures compared over time; and 3) which were the top related queries to searches for urologic oncology procedures.

RESULTS

Increased interest was found for all of the MIS procedures evaluated. Mean ARSV for robotic approach was higher for the search term 'prostatectomy" (44.8 vs. 13.5; p < 0.001) and 'partial nephrectomy" (27.1 vs.11.5; p = 0.02). No statistical difference was found for the search terms 'cystectomy" or 'nephrectomy". The analysis of mean (∆-ARSV) of MIS procedures measured between the first and last 12 months of the study period showed an increased interest with a more pronounced ∆-ARSV for robotic procedures. The top related searches for all surgical procedures were examined showing an increasing inquisitiveness with regards of type of urological cancers, treatment options, type of surgery and prognostic outcomes.

CONCLUSIONS

People are increasingly searching the web for MIS urological procedures. A growing appeal for robotics is demonstrated, especially for prostatectomy and partial nephrectomy where the robotic approach is gaining traction, suggesting a shift in mind-set amongst people seeking urological healthcare information.

Off-Clamp Robot-Assisted Partial Nephrectomy: Is There Something More to Achieve Optimal Trifecta Outcomes?

Objectives: To report trifecta outcomes of our "off-clamp" partial nephrectomy (PN) patients operated without main renal artery and/or any selective/superselective clamping. Materials and Methods: Between April 2008 and March 2020, 52 patients received "off-clamp" robot-assisted partial nephrectomy. Postoperative sixth month estimated glomerular filtration rate (eGFR) and eGFR decrease were considered for renal function evaluation. Patients with negative surgical margins, <15% postoperative eGFR decrease and absence of grade ≥2 Clavien-Dindo complications were reported to achieve trifecta outcomes. Results: Mean age and body mass index of the patients were 57.51 ± 12.99 years and 27.23 ± 4.35 kg/m², respectively. Mean preoperative hematocrit, serum creatinine, and eGFR were 42.01 ± 3.86%, 0.92 ± 0.28 mg/dL, and 85.26 ± 21.27 mL/min/1.73 m², respectively. Mean tumor size was 30.32 ± 13.64 mm. Mean PADUA and RENAL scores were 7.63 ± 1.46 and 6.21 ± 1.63, respectively. One patient had focal surgical margin positivity. Mean console time and estimated blood loss was 82.11 ± 38.51 minutes and 280.76 ± 278.98 mL, respectively. Complications were observed in two (4%) patients (one Clavien I, one Clavien IIIB). At postoperative sixth month, serum creatinine and eGFR were 0.95 ± 0.32 mg/dL and 83.65 ± 22.44 mL/min/1.73 m², respectively. Eventually seven patients had ≥15% postoperative eGFR decrease, one patient had grade ≥2 complication and one patient had positive surgical margin. Forty-three (83%) patients fulfilled trifecta outcomes. Conclusion: Off-clamp PN is important for optimal renal function preservation. Patient selection and additional operative measures along with experience in robotic procedure can contribute achievement of optimal trifecta outcomes.

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.

Nephrometry Scores: Can Preoperative Assessment of Sectional Imaging Really Mirror Intraoperative Renal Tumor Anatomy?

INTRODUCTION

To compare RENAL, preoperative aspects and dimensions used for an anatomical (PADUA) classification, and Mayo Adhesive Probability (MAP) scores with the respective intraoperative findings and surgeon's assessment in predicting surgical outcome of patients undergoing partial nephrectomy.

METHODS

Data of 150 eligible patients treated at the University Medical Center Mannheim between 2016 and 2018 were analyzed. Tumors were radiologically and intraoperatively assessed by PADUA, RENAL, and MAP scores and surgeon's assessment. Correlations and regression models were created to predict ischemia time (IT), major complications, and Trifecta (negative surgical margin, IT < 25 min, and absence of major complications).

RESULTS

There were strong correlations between radiological and intraoperative RENAL (r = 0.68; p < 0.001) and PADUA scores (r = 0.72; p < 0.001). Radiological RENAL, PADUA, and MAP scores and surgeon's assessment were independent predictors of Trifecta (OR = 0.71, p = 0.015; OR = 0.77, p = 0.035; OR = 0.65, p = 0.012; OR = 0.40, p = 0.005, respectively). IT showed significant associations with radiological RENAL, PADUA, and surgeon's assessment (OR = 1.41, p = 0.033; OR = 1.34, p = 0.044; OR = 3.04, p = 0.003, respectively). MAP score proved as only independent predictor of major complications (OR = 2.12, p = 0.002).

CONCLUSION

Radiologically and intraoperatively assessed scores correlated well with each other. Intraoperative nephrometry did not outperform radiological scores in predicting outcome confirming the value of the existing systems. MAP score correlates well with surgeon's assessment of perirenal fat and major complications underlining the importance of perirenal fat characteristics.

On-clamp versus purely off-clamp robot-assisted partial nephrectomy in solitary kidneys: comparison of perioperative outcomes and chronic kidney disease progression at two high-volume centers

BACKGROUND

Minimal literature describes the impact of hilar control on the progression to chronic kidney disease (pCKD) after robotic partial nephrectomy (RPN) in solitary kidneys (SK). The aim of this study was to compare purely off-clamp (ocRPN) vs. on-clamp robotic partial nephrectomy (onRPN) in SK and to identify predictors of pCKD at two high-volume centers.

METHODS

Between December 2013 and October 2019, 54 patients with SK underwent ocRPN and onRPN for renal tumors at two institutions. Baseline and perioperative data were analyzed. Newly onset of CKD stage 3b,4,5 (CKD3b,4,5) was assessed by Kaplan-Meier curves and compared for warm ischemia time (WIT) with the log-rank test. Cox regression analysis was used to identify predictors of pCKD.

RESULTS

At a median follow-up of 13 months (IQR 6.3-34), newly onset of CKD3b and CKD 4.5 were observed in 11.1% and 7.4% of patients, respectively. onRPN was associated with a higher risk of progression to CKD 3b,4,5 stages (P=0.034) and higher rate of perioperative complications (P=0.03). On univariable analysis eGFR at discharge (eGFRd), positive surgical margins status (PSM) and WIT were predictors of newly onset of CKD3b,4,5 (each P<0.05). Multivariable analysis identified eGFRd (HR 0.88; CI 95% 0.81-0.96) and WIT (HR 1.09; CI 95% 1.02-1.16) as independent predictors of pCKD (each P<0.01). Main limitations include the retrospective nature of the study, the short-term follow-up and the lack of data adjustment for parenchymal volume loss.

CONCLUSIONS

eGFRd and WIT during RPN are independent predictors of pCKD in SK. In this setting a critical reduction of WIT should be achieved according to the oncologic outcome. In patients with SK, WIT represents the only surgical modifiable factor of RPN for avoiding a quicker onset of pCKD.

Selective clamping during robot-assisted partial nephrectomy in patients with a solitary kidney: is it safe and does it help?

OBJECTIVES

To obtain the most accurate assessment of the risks and benefits of selective clamping in robot-assisted partial nephrectomy (RAPN) we evaluated outcomes of this technique vs those of full clamping in patients with a solitary kidney undergoing RAPN.

PATIENTS AND METHODS

Data from institutional review board-approved retrospective and prospective databases from 2006 to 2019 at multiple institutions with sharing agreements were evaluated. Patients with a solitary kidney were identified and stratified based on whether selective or full renal artery clamping was performed. Both groups were analysed with regard to demographics, risk factors, intra-operative complications, and postoperative outcomes using chi-squared tests, Fisher's exact tests, t-tests and Mann-Whitney U-tests.

RESULTS

Our initial cohort consisted of 4112 patients, of whom 72 had undergone RAPN in a solitary kidney (51 with full clamping and 21 with selective clamping). There were no significant differences in demographics, tumour size, baseline estimated glomerular filtration rate (eGFR), or warm ischaemia time (WIT) between the groups (Table 1). Intra-operative outcomes, including estimated blood loss, operating time, and intra-operative complications were similar in the two groups. Short- and long-term postoperative percentage change in eGFR, frequency of acute kidney injury (AKI), and frequency of de novo chronic kidney disease (CKD) were also not significantly different between the two techniques.

CONCLUSION

In a large cohort of patients with solitary kidney undergoing RAPN, selective clamping resulted in similar intra-operative and postoperative outcomes compared to full clamping and conferred no additional risk of harm. However, selective clamping did not appear to provide any functional advantage over full clamping as there was no difference observed in the frequency of AKI, CKD or change in eGFR. Short WIT in both groups (<15 min) may have prevented identification of benefits in the selective clamping group; a similar study analysing cases with longer WIT may elucidate any beneficial effects of selective clamping.

Single-port robotic partial and radical nephrectomies for renal cortical tumors: initial clinical experience

To describe our institution's initial experience with radical (RN) and partial nephrectomy (PN) using the SP robotic system. The recent FDA approval of the da Vinci^® SP robotic platform has led to its use in minimally invasive approaches to urologic malignancies. There are little data on its feasibility and safety after implementation for radical and partial nephrectomy. All patients who underwent PN or RN using the SP system at our institution were reviewed. All PNs were performed off-clamp. Patient demographics, preoperative imaging, operative approaches, and perioperative outcomes were collected and analyzed. Sixteen patients underwent PN (n = 13) or RN (n = 3) utilizing the SP robotic system between January 2019 and June 2019. Average age was 58.6 ± 13.9 and 61.0 ± 1.7 years in each group, respectively. A retroperitoneal approach was performed in 7 (53.8%) PN patients and 1 (33.3%) RN patient. A transperitoneal approach was performed in 6 (46.1%) PNs and 2 (66.7%) RNs. Mean operative time and median estimated blood loss for PN was 176.9 ± 64.0 min and 200 (50-800) ml compared to 176.3 ± 73.8 min and 50 (50-400) ml for RN. There was one operative conversion (7.7%) to an open approach in the PN group. Length of hospital stay postoperatively averaged 1.9 ± 1.3 days and 3.3 ± 1.2 days for patients undergoing partial and radical nephrectomy, respectively. SP partial and radical nephrectomies through transperitoneal and retroperitoneal approaches appear to be feasible surgical techniques in the management of cortical renal masses. Off-clamp PN is also a feasible approach using the SP system. However, further study is needed to establish its safety and use in renal surgery across multiple institutions and larger patient cohorts.