Ipsilateral renal function preservation after robot-assisted partial nephrectomy (RAPN): an objective analysis using mercapto-acetyltriglycine (MAG3) renal scan data and volumetric assessment

A Novel Classification System of Renal Hilar Tumors for Surgical Guidance: Technique, Outcome, and Safety

BACKGROUND

This study was designed to develop an innovative classification and guidance system for renal hilar tumors and to assess the safety and effectiveness of robot-assisted partial nephrectomy (RAPN) for managing such tumors.

METHODS

A total of 179 patients undergoing RAPN for renal hilar tumors were retrospectively reviewed. A novel classification system with surgical techniques was introduced and the perioperative features, tumor characteristics, and the efficacy and safety of RAPN were compared within subgroups.

RESULTS

We classified the tumors according to our novel system as follows: 131 Type I, 35 Type II, and 13 Type III. However, Type III had higher median R.E.N.A.L., PADUA, and ROADS scores compared with the others (all p < 0.001), indicating increased operative complexity and higher estimated blood loss [180.00 (115.00-215.00) ml]. Operative outcomes revealed significant disparities between Type III and the others, with longer operative times [165.00 (145.00-200.50) min], warm ischemia times [24.00 (21.50-30.50) min], tumor resection times [13.00 (12.00-15.50) min], and incision closure times [22.00 (20.00-23.50) min] (all p < 0.005). Postoperative outcomes also showed significant differences, with longer durations of drain removal (77.08 ± 18.16 h) and hospitalization for Type III [5.00 (5.00-6.00) d] (all p < 0.05). Additionally, Type I had a larger tumor diameter than the others (p = 0.009) and pT stage differed significantly between the subtypes (p = 0.020).

CONCLUSIONS

The novel renal hilar tumor classification system is capable of differentiating the surgical difficulty of RAPN and further offers personalized surgical steps tailored to each specific classification. It provides a meaningful tool for clinical practice.

Performance Prediction for Surgical Outcomes in Laparoscopic Partial Nephrectomy Using Nephrometry Scores: A Comparison of Zhongshan and Radius, Exophytic/Endophytic, Nearness, Anterior/Posterior, Location Systems

Objective: The aim of this study is to compare the precision and applicability of the Zhongshan (ZS) score against the radius, exophytic/endophytic, nearness, anterior/posterior, and location (RENAL) score in forecasting perioperative outcomes during laparoscopic partial nephrectomy (LPN). Materials and Methods: We retrospectively analyzed data from 99 renal cancer patients who underwent LPN between January 2017 and August 2023. Patients were scored and categorized based on both the ZS and RENAL scores. The study then compared perioperative outcomes across these groups and further investigated the correlation between ZS and RENAL scores and overall complication rates. Results: LPN was successfully accomplished in 94 patients, whereas 5 patients necessitated conversion to open or radical surgery. The high-risk group, according to the ZS score, manifested more warm ischemic time (WIT) than the low-risk group (P = .007). Furthermore, the incidence of overall complications escalated with increase in the ZS score grade (P = .045). A higher RENAL score corresponded to a greater risk of conversion to open or radical treatment (P = .012). Correlation analyses revealed associations between both ZS and RENAL scores and overall complications. The RENAL score also correlated with changes in blood creatinine values, while the ZS score was associated with WIT (all P < .05). In the univariate analysis, both ZS and RENAL scores were substantial factors for the occurrence of total complications (P = .029 and P = .027, respectively), but they were not statistically significant in the multivariate analysis. The receiver operating characteristic curves suggested that both individual and combined ZS and RENAL scores held predictive potential for the onset of overall complications (area under the curve = 0.652, 0.660, and 0.676, respectively). Conclusions: Compared with the RENAL score, the ZS score provides a more comprehensive assessment of tumor complexity in patients undergoing LPN. Integrating these two scores could potentially improve the accuracy of predicting surgical risks.

Perioperative, functional, and oncologic outcomes of laparoscopic partial nephrectomy versus open partial nephrectomy for complex renal tumors: a systematic review and meta-analysis

Background

The primary aim of this present study is to undertake a comprehensive comparative analysis of the perioperative, functional, and oncologic outcomes associated with laparoscopic partial nephrectomy (LPN) and open partial nephrectomy (OPN) as interventions for the treatment of complex renal tumors, defined as PADUA or RENAL score ≥ 7.

Methods

We systematically carried out an extensive search across four electronic databases, namely PubMed, the Cochrane Library, Embase, and Web of Science. Our objective was to identify pertinent studies published in the English language up to December 2023, and encompassed controlled trials comparing LPN and OPN as interventions for complex renal tumors.

Results

This study encompassed a total of seven comparative trials, involving 934 patients. LPN exhibited a noteworthy reduction in the length of hospital stay (weighted mean difference [WMD] -2.06 days, 95% confidence interval [CI] -2.62, -1.50; p < 0.00001), blood loss (WMD -34.05mL, 95% CI -55.61, -12.48; p = 0.002), and overall complications (OR 0.38, 95% CI 0.19, 0.79; p = 0.009). However, noteworthy distinctions did not arise between LPN and OPN concerning parameters such as warm ischemia time, renal function, and oncological outcomes.

Conclusions

This study reveals that LPN presents several advantages over OPN. These benefits encompass a shortened hospital stay, diminished blood loss, and a reduced incidence of complications. Importantly, LPN achieves these benefits while concurrently upholding comparable renal function and oncological outcomes.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=457716, identifier CRD42023453816.

Perioperative, functional, and oncologic outcomes of minimally-invasive surgery for highly complex renal tumors (RENAL or PADUA score ≥ 10): an evidence-based analysis

The primary objective of the current study is to undertake a comparative analysis of the effectiveness and safety of minimally-invasive partial nephrectomy (MIPN; including laparoscopic and robotic approaches) and open partial nephrectomy (OPN) for the treatment of highly complex renal tumors (defined as PADUA or RENAL score ≥ 10). A comprehensive search was conducted in four electronic databases (PubMed, Web of Science, Embase, and Cochrane Library) to identify relevant studies published in the English language up to April 2023. The current study employed Review Manager 5.4 and encompassed controlled trials of both MIPN and OPN for the treatment of highly complex renal tumors. This study comprised a total of eight comparative trials involving 1161 patients. MIPN demonstrated a significant reduction in length of hospital stay (weighted mean difference [WMD] - 2.08 days, 95% confidence interval [CI] - 2.48, - 1.68; p < 0.00001), blood loss (WMD - 39.86 mL, 95% CI - 75.32, - 4.39; p = 0.03), transfusion rates (odds ratio [OR] 0.30, 95% CI 0.13, 0.71; p = 0.006), and overall complications (OR 0.46, 95% CI 0.31, 0.70; p = 0.0003). However, there were no significant differences between MIPN and OPN in terms of operative time, warm ischemia time, conversion to radical nephrectomy rates, renal functional and oncologic outcomes. This study reveals that MIPN presents several benefits in comparison to OPN, including decreased length of hospital stay, blood loss, transfusion rates, and complications, while still offering renal functional and oncological outcomes that are comparable to those of OPN in patients with highly complex renal tumors.

Comparisons of the Safety and Effectiveness of Robot-Assisted vs Laparoscopic Partial Nephrectomy for Central Renal Angiomyolipomas: A Propensity Score-Matched Analysis Study

Objective: To compare the safety and effectiveness of robot-assisted partial nephrectomy (RAPN) vs laparoscopic partial nephrectomy (LPN) in the treatment of central renal angiomyolipomas (AMLs). Methods: We retrospectively analyzed the clinical data of 103 patients who were treated with either RAPN or LPN for central AMLs between January 2017 and June 2022. Propensity scores were matched according to sex, age, laterality, body mass index, symptoms, diameter of tumor, location of tumor distribution, R.E.N.A.L score, preoperative hemoglobin, preoperative serum creatinine, preoperative estimated glomerular filtration rate, chronic disease, previous abdominal surgery, preoperative selective arterial embolization, American Society of Anesthesiologists scale, and duration of follow-up, and after matching, perioperative and prognostic data of the two groups were compared. Results: A total of 57 patients underwent RAPN, and 46 patients underwent LPN. Before matching, there were more complex AMLs in the RAPN group, and R.E.N.A.L scores differed between the two groups (10 vs 9, p < 0.001). After matching, the median warm ischemic time in the RAPN group was significantly shorter than that in the LPN group (21.5 minutes vs 28 minutes, p = 0.034), as well as the median time of postoperative mobilization (1 day vs 2 days, p < 0.001). The other indicators were not significantly different between the groups. Conclusions: For central AMLs, both RAPN and LPN were safe and feasible surgical treatments, but RAPN might be associated with shorter warm ischemia time and earlier postoperative mobilization.

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.

Perioperative, functional, and oncologic outcomes of robot-assisted versus open partial nephrectomy for complex renal tumors (RENAL score ≥ 7): an evidence-based analysis

This study aims to assess the efficacy and safety of robot-assisted partial nephrectomy (RAPN) compared with open partial nephrectomy (OPN) in the management of complex renal tumors (defined as RENAL score ≥ 7). We conducted a comprehensive literature search in PubMed, Embase, Web of Science, and Cochrane Library to identify relevant comparative studies up to January 2023. This study was conducted with the Review Manager 5.4 software, and included RAPN and OPN-controlled trials for complex renal tumors. The prime outcomes were to assess the perioperative results, complications, renal function, and oncologic outcomes. A total of 1493 patients were included in seven studies. Compared to OPN, RAPN was associated with a significantly shorter hospital stay (weighted mean difference [WMD] - 1.53 days, 95% confidence interval [CI] - 2.44, - 0.62; p = 0.001), less blood loss (WMD - 95.88 mL, 95% CI - 144.19, - 47.56; p = 0.0001), lower transfusion rates (OR 0.33, 95% CI 0.15, 0.71; p = 0.005), fewer major complications (OR 0.63, 95% CI 0.39, 1.01; p = 0.05), and fewer overall complications (OR 0.49, 95% CI 0.36, 0.65; p < 0.00001). Nevertheless, no statistically significant differences were found between the two groups in operative time, warm ischemia time, estimated glomerular decline, intraoperative complications, positive surgical margins, local recurrence, overall survival, and recurrence-free survival. The study demonstrated that RAPN had superior perioperative parameters and fewer complications when compared to OPN for complex renal tumors. However, no significant differences were found in terms of renal function and oncologic outcomes.

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?

Perioperative, oncologic, and functional outcomes of robot-assisted partial nephrectomy for special types of renal tumors (hilar, endophytic, or cystic): an evidence-based analysis of comparative outcomes

Purpose

This study aims to perform a pooled analysis to compare the outcomes of robot-assisted partial nephrectomy (RAPN) between complex tumors (hilar, endophytic, or cystic) and non-complex tumors (nonhilar, exophytic, or solid) and evaluate the effects of renal tumor complexity on outcomes in patients undergoing RAPN.

Methods

Four databases were systematically searched, including Science, PubMed, Web of Science, and Cochrane Library, to identify relevant studies published in English up to December 2022. Review Manager 5.4 was used for statistical analyses and calculations. The study was registered with PROSPERO (Registration number: CRD42023394792).

Results

In total, 14 comparative trials, including 3758 patients were enrolled. Compared to non-complex tumors, complex tumors were associated with a significantly longer warm ischemia time (WMD 3.67 min, 95% CI 1.78, 5.57; p = 0.0001), more blood loss (WMD 22.84 mL, 95% CI 2.31, 43.37; p = 0.03), and a higher rate of major complications (OR 2.35, 95% CI 1.50, 3.67; p = 0.0002). However, no statistically significant differences were found between the two groups in operative time, length of stay, transfusion rates, conversion to open nephrectomy and radical nephrectomy rates, estimated glomerular filtration rate (eGFR) decline, intraoperative complication, overall complication, positive surgical margins (PSM), local recurrence, and trifecta achievement.

Conclusions

RAPN can be a safe and effective procedure for complex tumors (hilar, endophytic, or cystic) and provides comparable functional and oncologic outcomes to non-complex tumors.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=394792, identifier CRD42023394792.

Comparison of surgical outcomes and split renal function between laparoscopic and robot-assisted partial nephrectomy: a propensity score-matched analysis

PURPOSE

The objective of this study was to compare perioperative outcomes and total and split renal function between laparoscopic partial nephrectomy (LPN) and robot-assisted partial nephrectomy (RAPN). Predictive risk factors of preservation of operated renal function were also assessed.

METHODS

We retrospectively analyzed 173 patients who underwent LPN (n = 84) or RAPN (n = 89) between 2010 and 2020. After propensity score matching (1:1), perioperative outcomes and total and split renal function were assessed. Logistic regression analysis was used to evaluate predictive risk factors of preservation of operated renal function. Trifecta criteria were defined as negative surgical margins, warm ischemia time (WIT) < 25 min, and no complications more than Clavien-Dindo grade II within 4 weeks after surgery. Split renal function was evaluated by mercaptoacetyltriglycine renal scan.

RESULTS

After propensity score matching, 42 patients were allocated to each group. RAPN was associated with significantly shorter WIT (RAPN vs LPN: 12 vs 22 min; p < 0.0001) and higher trifecta achievement rate (93.3 vs 64.2%; p < 0.0001). Other perioperative outcomes and total and split renal function were not significantly different between LPN and RAPN. The R.E.N.A.L. nephrometry score (RNS) was a predictive risk factor of preservation of operated renal function in the multivariable logistic regression analysis (odds ratio 1.68, 95% confidence interval 1.29-2.20, p < 0.0001).

CONCLUSIONS

RAPN improved WIT and trifecta achievement rate, but it did not improve the preservation of operated renal function, for which RNS was found to be a strong predictive risk factor.

Influence of robot-assisted partial nephrectomy on long-term renal function as assessed using DTPA renal scintigraphy

BACKGROUND

The long-term split renal function after robot-assisted partial nephrectomy (RAPN) is yet to be elucidate. This study aimed to assess long-term renal function RAPN, using renal scintigraphy, and to identify clinical factors related to deterioration of renal function on the affected side of the kidney.

PATIENTS AND METHODS

RAPN for small tumors was performed, and split renal function was evaluated using DTPA renal scintigraphy before and 1 year after surgery. Clinical factors (age, sex, body mass index, tumor side, presence of urinary protein, diabetes, hypertension, and dyslipidemia), perioperative factors (renal nephrectomy score [RNS], tumor diameter, overall surgery duration, console time, warm ischemic time, amount of bleeding), and renal function (estimated glomerular filtration rate (eGFR) and glomerular filtration rate (GFR) measured using scintigraphy on both the affected and contralateral kidneys) were analyzed.

RESULTS

Sixty-six patients were included in the study. The median eGFR decreased from 71.9 ml/min to 63.9 ml/min after 1 year (p<.001), accounting for a mean loss of 10.1%. In scintigraphy examination, the median GFR on the affected kidney side decreased from 41.1 ml/min to 33.7 ml/min after 1 year (p<.001), accounting for a mean loss of 16.8%. RNS was significantly associated with renal function. Among RNS factors, the N factor is　associated with renal function after RAPN.

CONCLUSION

RNS, particularly the N factor, possibly influences the long-term deterioration of renal function after RAPN.

Robotic-assisted laparoscopic tumor enucleation is a feasible technique for renal hilar tumors: A retrospective study

BACKGROUND AND OBJECTIVE: This study aimed to evaluate the safety and efficacy of robot-assisted laparoscopic tumor enucleation (RAE) for the treatment of renal hilar tumors and to describe our experience with renorrhaphy-related surgical techniques.

METHODS

Retrospective data were collected from 173 consecutive patients who underwent RAE for localized renal tumors (cT1-cT2N0M0) at our hospital between September 2014 and November 2019.

RESULTS

Seventy-five patients had renal hilar tumors and 98 patients had nonhilar tumors. There were no statistical differences between the hilar and nonhilar groups in operation time (190 [115-390] vs. 190 [110-390] min, p = 0.889), warm ischemia time (26 [12-60] vs. 27 [17-41] min, p = 0.257), hospital stay duration (8 [3-16] vs. 7.5 [4-18] days, p = 0.386), renal function (estimated glomerular filtration rate, 102.5 [29.4-144] vs. 101.3 [64.2-134.7] ml/min/1.73 m² , p = 0.631); creatinine level, (76 [43-169] vs. 78.5 [50-281.3] µmol/L, p = 0.673), perioperative complications rate, or surgical margin status. However, patients with hilar tumors lost significantly more blood than did those with nonhilar tumors (250 [50-1500] vs. 200 [20-1200] ml, p = 0.007). During the follow-up period (median, 30 months), three patients in each group experienced recurrence. The 5-year recurrence-free rates were 93.0% and 95.4% in the hilar and nonhilar tumor groups, respectively (p = 0.640).

CONCLUSIONS

For experienced robot laparoscopists, RAE is a safe, effective, and feasible procedure for renal hilar tumors, without increased risk of positive surgical margins or worse midterm oncologic outcomes compared with nonhilar tumors.

Clinical advantages of robot-assisted partial nephrectomy versus laparoscopic partial nephrectomy in terms of global and split renal functions: A propensity score-matched comparative analysis

OBJECTIVES

To identify predictors of renal function preservation, and to compare the global and split renal function outcomes of robot-assisted partial nephrectomy and laparoscopic partial nephrectomy.

METHODS

Demographic, operative and pathological data, as well as renal function outcomes, of 251 patients who underwent laparoscopic (n = 104) and robot-assisted (n = 147) partial nephrectomy between 2008 and 2018 were retrospectively analyzed. Propensity score matching (1:1) was carried out to adjust for potential baseline confounders. Functional outcomes were assessed based on the estimated glomerular filtration rate and dynamic renal scintigraphy (using ^99m Tc-mercaptoacetyltriglycine), including renal volumetric analysis.

RESULTS

A total of 98 patients were allocated to each partial nephrectomy group. Ischemic (laparoscopic vs robot-assisted partial nephrectomy: 29 vs 15 min, P < 0.001) and operative times (181 vs 100 min, P < 0.001) were shorter in robot-assisted partial nephrectomy. The preservation ratio of global renal function at 3 months (88.3% vs 91.4%, P = 0.040) and 12 months (87.8% vs 91.5%, P = 0.010) postoperatively, and the renal function of the operated kidney (80.3% vs 88.2%, P < 0.001) were greater after robot-assisted partial nephrectomy. In robot-assisted partial nephrectomy, the volume of resected parenchyma was significantly smaller (27.2 vs 15.5 mL, P < 0.001), resulting in greater postoperative normal parenchymal volumes (120 vs 132 mL, P < 0.001) and a greater parenchymal preservation ratio (81.1% vs 90.1%, P < 0.001). The parenchymal preservation ratio was the strongest predictor of renal function preservation after surgery (P < 0.001, odds ratio 6.02).

CONCLUSIONS

Robot-assisted partial nephrectomy allows better preservation of split renal function than laparoscopic partial nephrectomy by increasing the parenchymal preservation ratio. This translates into better postoperative global renal function.

Global Analysis of Research Trends on Kidney Function After Nephron-Sparing Surgery: A Bibliometric and Visualised Study

BACKGROUND

Nephron-sparing surgery (NSS) for small renal masses (SRMs) is currently the standard of care to treat renal cell carcinoma (RCC). The concept of partial resection of RCC has mainly been developed to preserve kidney function. Therefore, we have performed this study to explore the research activity that has been undertaken since the early twenty-first century to investigate the advantages of NSS on preserving kidney function and preventing chronic kidney disease (CKD).

METHODS

Based on the Scopus database, this bibliometric study was used to reveal publication patterns in the kidney function and NSS research field. The data were analysed with VOSviewer version 1.6.16 software, which was used to create a network visualisation map that included research hotspots in this area.

RESULTS

A total of 449 scientific publications focused on renal function in NSS between 2001 and 2020. One hundred and seventy (38%) of the total published articles originated from the USA. Journal of Urology, European Urology, and Journal of Endourology were the top publications detailing research in this field. Half (50%) of the top 10 cited articles were published in the Journal of Urology, with an average citation of around 200 per article. The three most encountered research themes were comparative studies between partial and radical nephrectomy in terms of kidney function and development of CKD, the impact of type and duration of ischemia during resection on glomerular filtration rate (GFR) decline, and the effect of different surgical approaches on intermediate and long-term kidney function.

CONCLUSION

NSS for SRMs and RCC and its impact on kidney function is a hot topic in the literature, and the amount of published data has consistently been rising since 2000. However, even though hundreds of documents have studied this topic from various perspectives, there is a compelling need to answer several questions such as the overall survival (OS) benefit of performing NSS in localised RCC and head-to-head comparison of robotic-assisted versus laparoscopic NSS in terms of warm ischemia time and long-term decline in GFR.

Determinants and Implications of Excised Parenchymal Mass on Robotic-Assisted Partial Nephrectomy Outcomes

OBJECTIVES

To evaluate the association between excised parenchymal mass (EPM) and postoperative renal function (eGFR) following robotic-assisted partial nephrectomy (RAPN). EPM is the amount of healthy renal parenchyma excised during partial nephrectomy in order to achieve safe surgical margins.

METHODS

We evaluated 406 consecutive RAPN performed by a single surgeon to eliminate variations in technique as a factor in EPM. EPM (mL) = (specimen volume * π/6) - (tumor volume * π/6). RENAL score was categorized as easy (4-6), moderate (7-9), or hard (10-12). EPM was grouped into four categories: ≤ 3.9 mL, 4.0-9.9 mL, 10.0-17.7 mL, and >17.7 mL. eGFR was evaluated preoperatively, postoperative day 1 (POD1), 1 month, and 6 months postoperatively.

RESULTS

Median age was 63 years (22-84 years), 252 (62.1%) were male, and median EPM was 9.9 mL (interquartile range 3.9 to 17.7 mL). The median EPM and interquartile range for each RENAL category was 3.7 mL (2.0, 7.9), 12 mL (5.7, 19.4), and 16.2 mL (7.9, 24.3), respectively. Higher EPM was associated with worse changes in eGFR at POD1 (P = 0.005) and 1 month after RAPN (P = 0.002) but was not statistically significant at the 6-month time period (P = 0.35) CONCLUSION: Increased tumor complexity is associated with an increase in EPM during RAPN. Increased EPM is associated with eGFR decline at POD1 and 1 month post RAPN but not at 6 months postoperatively.

External validation of the Simplified PADUA REnal (SPARE) nephrometry system in predicting surgical outcomes after partial nephrectomy

BACKGROUND

Pentafecta is a major goal in the era of partial nephrectomy (PN). Simplified PADUA REnal (SPARE) nephrometry system was developed to evaluate the complexity of tumor. However, the predictive ability in pentafecta of SPARE system is yet to be determined. The aim of this study was to externally validate the applicability of SPARE nephrometry system in predicting pentafecta achievement after partial nephrectomy, and to examine inter-observer concordance.

METHODS

We retrospectively reviewed data of 207 consecutive patients who underwent PN between January 2012 and August 2018 at a tertiary referral center. We obtained SPARE, R.E.N.A.L., and PADUA scores and evaluated correlations among the nephrometries and surgical outcomes including pentafecta by Spearman test. Logistic regression analysis was used to identify independent predictors of pentafecta outcomes. We compared the nephrometries to determine the predictive ability of achieving pentafecta using receiver operating characteristic curve analysis. Fleiss' generalized kappa was used to assessed interobserver variation in the SPARE system.

RESULTS

Based on the SPARE system, 120, 74, and 13 patients were stratified into low-risk, intermediate-risk, and high-risk groups, respectively. Regarding the individual components of pentafecta, there were significant differences in the complication rate (p = 0.03), ischemia time (p < 0.001), and percent change of eGFR (p < 0.001) among the three risk groups. In addition, higher tumor complexity was significantly associated with a lower achievement rate of pentafecta (p = 0.01). In Spearman correlation tests, SPARE nephrometry was correlated with ischemia time (ρ:0.37, p < 0.001), operative time (ρ:0.28, p < 0.001), complication rate (ρ:0.34, p < 0.001), percent change of eGFR (ρ:0.34, p < 0.001), and progression of chronic kidney disease stage (ρ:0.17, p = 0.02). Multivariate analysis revealed that SPARE significantly affected pentafecta (OR: 0.67, p < 0.001). In ROC curve analysis, SPARE showed fair predictive ability in the achievement pentafecta (AUC: 0.71). The predictive ability of pentafecta was similar between nephrometries (SPARE vs. R.E.N.A.L., p = 0.78; SPARE vs. PADUA, p = 0.66). The interobserver concordance of SPARE was excellent (Kappa: 0.82, p = 0.03).

CONCLUSIONS

SPARE system was a predictive factor of surgical outcomes after PN. This refined nephrometry had similar predictive abilities for pentafecta achievement compared with R.E.N.A.L. and PADUA.

Retroperitoneal Versus Transperitoneal Robotic Partial Nephrectomy: A Multicenter Matched-pair Analysis

BACKGROUND

With increasing acceptance of robotic partial nephrectomy over the last decade, there is an ongoing discussion about the transperitoneal versus retroperitoneal access.

OBJECTIVE

To report outcomes after transperitoneal (TRPN) versus retroperitoneal (RRPN) robotic partial nephrectomy.

DESIGN, SETTING, AND PARTICIPANTS

A total of 754 patients were identified from the databases of three high-volume centers who underwent either TRPN (n = 551) or RRPN (n = 203).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Perioperative data were evaluated retrospectively. A propensity score matched-pair analysis was performed with the following variables: grade of renal insufficiency, age, body mass index, tumor diameter, and preoperative aspects and dimensions used for an anatomical (PADUA) score with a subsequent subgroup analysis for tumor location. For quality outcomes, the margin, ischemia, and complications (MIC) criteria were used (negative margins, ischemia time <20 min, and no major complications). Statistical analyses included chi-square and Mann-Whitney U tests.

RESULTS AND LIMITATIONS

In all, 176 patients could be matched in each group. The median tumor diameter was 28 mm with a PADUA score of 9. In 11% of RRPN versus 44% of TRPN cases, an anterior tumor location was found, and in 55% versus 30%, a posterior lesion was found (p < 0.001). Operative time (119 vs 139 min, p < 0.001) and warm ischemia time (9 vs 10 min, p = 0.003) were significantly shorter for RRPN. No significant differences were observed between intra- and postoperative complication rates, with 8% major complications in TRPN versus 3% in RRPN (p = 0.06). The MIC criteria were achieved in 90% in the RRPN versus 88% in the TRPN group, without differences for tumor location.

CONCLUSIONS

Significant differences between TRPN and RRPN could be found for intraoperative time, while complication rates and quality outcomes were comparable. RRPN can also be a considerable alternative for anterior tumors.

PATIENT SUMMARY

In this study, we demonstrate that robotic partial nephrectomy is feasible with either a transperitoneal or a retroperitoneal surgical access. The posterior approach can also be used for anterior renal tumors and may result in shorter operative time.

Correlation between preoperatively predicted and postoperatively observed renal function using an imaging-based approach: A retrospective cohort study

The aim of the present study was to preoperatively predict renal function following partial nephrectomy (PN) using an imaging-based approach and to examine the correlation between preoperatively predicted and postoperatively observed renal function in the study cohort. A total of 128 consecutive patients who underwent PN between May 2015 and March 2018 and had available clinical data were included in this study. A hand-scripting method was used to estimate the defected volume (Vdef) from preoperative computerized tomography scans, whereas a cylindrical method was used to obtain preoperative renal volume (Vpre). The function index (FI) was proposed as a new term to estimate preserved parenchyma percentage following PN. The FI was defined as f=(Vpre-Vdef)/Vpre for the operated kidney and adjusted as FI=0.5 × (f + 1) for the bilateral kidneys. The estimated glomerular filtration rates (GFRs) before surgery, one day after surgery and ~12 months after surgery were calculated using the Modification of Diet in Renal Disease Study equation. The GFR rate after PN was predicted by multiplying the preoperative GFR by the FI. The predictive role of the FI was further tested using multiple linear regression and correlation analyses. The median FI in the present study was 94% for unilateral kidney surgery and adjusted to 97% for bilateral kidneys. Linear correlation analysis revealed that the predicted GFR significantly correlated with the observed immediate postoperative GFR (R², 0.594) and observed late postoperative GFR (R², 0.828). In multivariate regression analysis, preoperative GFR (P<0.01) and warm ischemic time (P<0.01) were identified as independent determinants of the immediate postoperative renal function, whereas only FI (P<0.01) and preoperative GFR (P<0.01) were identified as independent determinants of late renal function after PN. The preoperatively predicted renal function using an imaging-based approach had a significant positive correlation with the postoperatively observed renal function. The FI estimated from the preoperative diagnostic images in the present study was identified as an independent determinant of long-term renal function after PN.

Endophytic Renal Cell Carcinoma Treated with Robot-Assisted Surgery: Functional Outcomes - A Comprehensive Review of the Current Literature

INTRODUCTION

Robotic surgery for the management of localized renal cell carcinoma (RCC) has gained increasing popularity during the last decade. An endophytic renal tumour represents a surgical technical challenge in terms of identification and resection related to the lack of external visual cues on the kidney surface.

MATERIALS AND METHODS

There is little evidence of functional outcomes of robotic surgery on treating endophytic masses. For this reason, we wanted to review the contemporary literature on the functional outcomes of endophytic RCC treated with robotic surgery.

RESULTS

Many studies investigating robotic partial nephrectomy for totally endophytic RCC confirmed the good functional results of this approach at intermediate follow-up. The greater relative importance of volume loss versus ischaemia duration in predicting long-term renal function after partial nephrectomy is now established, and the robotic technique may facilitate volume preservation. Accurate use of intra-operative ultrasonography, enucleation, and intra-operative techniques using near-infrared fluorescence imaging with indocyanine green dye could minimize excision of the parenchyma and prevent devascularization of adjacent healthy parenchyma.

CONCLUSIONS

Unfortunately, the overall quality of the literature evidence and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the surgical technique used and functional outcomes.

Split renal function in patients with renal masses: utility of parenchymal volume analysis vs nuclear renal scans

OBJECTIVES

To evaluate the utility of parenchymal volume analysis (PVA) for estimation of split renal function (SRF) in patients with renal masses. SRF is important for deciding about partial vs radical nephrectomy (PN/RN) and assessing risk for developing severe chronic kidney disease after surgery. For renal donors PVA is routinely used to estimate SRF, but the utility of PVA for the more complex renal mass population remains undefined.

PATIENTS AND METHODS

All patients (n = 374) with renal tumours and a normal contralateral kidney managed with PN (2010-2018), with preoperative/postoperative nuclear renal scans (NRS) and cross-sectional imaging were analysed. Parenchymal volumes were measured by free-hand scripting or software analysis. Concordance between ipsilateral estimated glomerular filtration rate (eGFR) values based on SRF from NRS vs PVA were evaluated by Pearson correlation and Bland-Altman plots. Parallel analysis of all 155 patients managed with RN at our centre (2006-2016) with preoperative NRS and imaging was also performed.

RESULTS

For PN, the median age and tumour size were 62 years and 3.4 cm, respectively. The median preoperative ipsilateral parenchymal volume and eGFR were 181 cm³ and 36.9 mL/min/1.73 m² , respectively. Parenchymal volumes estimated by free-hand scripting vs software analyses correlated strongly (r = 0.98, P < 0.001). Preoperative ipsilateral eGFR based on SRF from PVA vs NRS also correlated strongly (r = 0.94, P < 0.001). Ipsilateral eGFR saved after PN correlated strongly with parenchymal volume preserved (all r >0.60); however, the correlation was much stronger when ipsilateral eGFRs were based on SRF from PVA rather than NRS (z-statistic = 3.15, P = 0.002). For RN patients, preoperative eGFR in the contralateral kidney based on SRF from PVA vs NRS also correlated strongly (r = 0.87, P < 0.001).

CONCLUSION

PVA has utility for estimation of SRF in patients with renal masses, even though this population is older and more comorbid than renal donors and the tumour can complicate the analysis. PVA can be obtained by software analysis from preoperative cross-sectional imaging and thus readily incorporated into routine clinical practice.

The role of three-dimensional reconstruction in laparoscopic partial nephrectomy for complex renal tumors

BACKGROUND

To evaluate the role of three-dimensional (3D) reconstruction technique in renal function protection and ipsilateral parenchymal mass preserved after laparoscopic partial nephrectomy (LPN) in patients with complex renal tumor (R.E.N.A.L.score ≥ 8).

METHODS

A retrospective study enrolling 49 patients who suffered from RCC and underwent LPN at our center, from October 1, 2017, to October 31, 2018. Twenty-one patients (group A) underwent LPN with the 3D reconstruction technique before surgery, and the other 28 patients (group B) not. Preoperative and postoperative ipsilateral parenchymal mass volume and ipsilateral glomerular filtration rate (GFR) were analyzed 3-5 days prior and 3 months after PN. In order to compare the two groups, Mann-Whitney U test and chi-square tests were performed. The main limitation of this technique is that the volume calculations are partly performed manually.

RESULTS

All patients' median renal score was 10 with no difference between the two groups (P = 0.89), and the median tumor size of the two groups was 3.2 cm (group A) and 3.3 cm (group B) respectively (P = 0.14). In addition, the median warm ischemia time of the two groups was 21 min (group A) and 26 min (group B) (P = 0.003). In group A and group B, the rate of preserved global GFR was 88% and 86% (P = 0.06), preserved ipsilateral GFR was 80% and 77% (P = 0.01), and preserved ipsilateral parenchymal was 84% and 80% (P = 0.03) separately.

CONCLUSION

3D reconstruction technique was a beneficial method for more renal function and more preserved renal parenchymal mass volume after LPN.

TRIAL REGISTRATION

Yantai Yuhuangding Hospital, YHD[2017]212. Registered 1 January 2017 (prospectively registered), http://www.ytyhdyy.com/nav/103.htm .

The role of RENAL, PADUA, C-index, CSA nephrometry systems in predicting ipsilateral renal function after partial nephrectomy

Background

Functional outcome is an important issue in nephron-sparing surgery. Various nephrometries have been developed to predict renal function preservation. The aim of this study was to examine the applicability of R.E.N.A.L., PADUA, C-index, and mathematical tumor contact surface area (CSA) in predicting ipsilateral renal function after partial nephrectomy using radio-isotope scans.

Methods

We performed this retrospective study in patients who underwent partial nephrectomy between May 2013 and April 2017, and used abdominopelvic computerized tomography or magnetic resonance imaging to obtain R.E.N.A.L., C-index, and CSA. Renal function was measured by 99mTc mercaptoacetyltriglycine (MAG3). We evaluated correlations between nephrometries and perioperative parameters, and comparatively analyzed different nephrometries to determine the predictive ability in the percent change of effective renal plasma flow of the affected kidney.

Results

Three, two, and 35 patients received partial nephrectomy in open, laparoscopic, and robotic approaches, respectively. The median (IQR) tumor size was 3.13 (2.4) cm. The median (IQR) R.E.N.A.L., PADUA, C-index, and CSA scores were 7 (3), 8 (2), 2.01 (1.87), and 14.14 (19.25) cm², respectively. Spearman correlation analysis showed that four nephrometries were correlated with each other. The strongest correlations were between CSA and C-index (coefficient: − 0.885, p < 0.001), followed by R.E.N.A.L. and PADUA (coefficient: 0.778, p < 0.001). Ischemia time was significantly correlated with R.EN.A.L. (coefficient: 0.35, p = 0.025), PADUA (coefficient: 0.42, p = 0.007), C-index (coefficient: − 0.45, p = 0.004), and CSA (coefficient: 0.41, p = 0.009). In multivariate analysis, PADUA significantly affected ischemia time (p = 0.04). The percent change in effective renal plasma flow (PCE) of the operated kidney was correlated with PADUA (coefficient: 0.48 p = 0.002), C-index (coefficient: − 0.74, p < 0.001), and CSA (coefficient: 0.75, p < 0.001). Only CSA and C-index independently affected PCE (both p < 0.05) in multivariate analysis. In ROC curve analysis, both C-index and CSA could predict 20% change in effective renal plasma flow (AUC: 0.91 vs 0.86, p = 0.2) of the affected kidney.

Conclusions

We suggest using PADUA to evaluate surgical complexity and ischemia time. Regarding the accuracy of the prediction of post-operative ipsilateral renal function, both CSA and C-index outperformed R.E.N.A.L. and PADUA nephrometries.

"At-risk" kidney: How surgical factors influence renal functional preservation after partial nephrectomy

OBJECTIVES

To investigate the influence of surgical modifiable factors on chronic kidney disease upstaging in a contemporary cohort of patients with normal and "at-risk" kidneys undergoing partial nephrectomy.

METHODS

We reviewed 778 consecutive patients with (n = 634)/without (n = 144) chronic kidney disease or risk factors for chronic kidney disease in our institutional partial nephrectomy database. Chronic kidney disease upstaging was assessed using glomerular filtration rate measurements preoperatively and at 3-12 months postoperatively. Using a multivariate logistic regression, baseline clinicodemographic factors, and the operative measurements of excisional volume loss and warm and cold ischemia time on rates of chronic kidney disease upstaging were determined. Marginal effects were used to analyze the impact of ischemia time and generate interaction curves.

RESULTS

Chronic kidney disease/risk factors for chronic kidney disease had equivalent rates of chronic kidney disease upstaging as the healthy kidney cohort (31.5% vs 38.2%, P = 0.15). Of the entire cohort, 2.8% were upstaged to stage IV-V chronic kidney disease. Multivariate analysis found a significant association between chronic kidney disease upstaging and excisional volume loss in both cohorts (no chronic kidney disease/risk factors for chronic kidney disease: odds ratio 1.63, P = 0.04; chronic kidney disease/risk factors for chronic kidney disease: odds ratio 1.42, P = 0.001). Only in the chronic kidney disease/risk factors for chronic kidney disease cohort, there was an association between ischemia type/duration and chronic kidney disease upstaging (odds ratio 1.04, P = 0.04). Warm ischemia began to predict an increased risk of chronic kidney disease upstaging at 17.6 min, which became statistically significant at 49 min.

CONCLUSIONS

Chronic kidney disease upstaging is common after partial nephrectomy. Although volume loss unequivocally affects rates of upstaging irrespective of baseline renal function, warm ischemia time disproportionately influences "at-risk" kidneys. Therefore, strong consideration should be given to minimizing volume loss and using cold ischemia when extended clamp times are anticipated in "at-risk" kidneys.

Organ-sparing procedures in GU cancer: part 1-organ-sparing procedures in renal and adrenal tumors: a systematic review

PURPOSE

Organ-sparing surgery (OSS) for the kidney and adrenals has emerged as the need for preservation of function is paramount in patients with poor functional reserve. As reports increasingly showed that oncological outcomes were equivalent to radical excision, elective OSS became a viable alternative in patients with otherwise normal reserve. In this review, we summarize the current knowledge of OSS for adrenal and renal tumors.

MATERIALS AND METHODS

PubMed, Web of Science and Cochrane Library Central Search were searched for recently published articles up to December 2017. The following keywords were used; "partial adrenalectomy", "adrenal sparing", "partial nephrectomy", "nephron sparing", "kidney/renal cancer".

RESULTS

Partial adrenalectomy became an attractive alternative to total adrenalectomy avoiding adrenal insufficiency. Both minimally invasive surgery and ablative techniques were increasingly reported for adrenal OSS with adequate residual adrenal function and excellent oncological outcome. Radical nephrectomy remained for many years as the gold standard of treatment for organ-confined renal cell carcinoma. As the need to reduce the impact on renal function, more conservative approaches were utilized. Soon, the non-inferiority of nephron-sparing surgery to that of radical excision became evident and elective partial nephrectomy was gaining ground as the standard of care for small renal masses in patients with normal contralateral kidneys.

CONCLUSIONS

Herein, we present a comprehensive review of the current status of OSS in renal and adrenal tumors.

The 3-D Volumetric Measurement Including Resected Specimen for Predicting Renal Function AfterRobot-assisted Partial Nephrectomy

OBJECTIVE

To investigate the relationship between postoperative renal function and resected cortex margin volume calculated by a 3-dimensional reconstruction technique based on the resected specimen, and to determine predictors of renal function after robot-assisted partial nephrectomy.

METHODS

A total of 114 patients underwent robot-assisted partial nephrectomy from 2014 to 2018. Patients without a 1 mm slice computed tomography or renal scintigraphy were excluded. We identified the margins of the tumor from each resected specimen with 2 mm margin being added as the ischemic margin. The volume of the renal cortex was calculated automatically using 3-dimensional volume analyzer software. The total margin volume was excluded from the ipsilateral cortex volume to calculate the cortex volume split. Predicted estimated glomerular filtration rate (eGFR) was calculated using the change in cortex volume and then compared with the actual eGFR.

RESULTS

Eighty-two patients were included in this retrospective study. Sixty-six patients (80%) were cT1a. A strong correlation was observed between renal scintigraphy split and pre- and postoperative cortex volume split (Pearson correlation coefficient r = 0.9330 and 0.8742, respectively). The predicted eGFR correlated strongly with post 1, 3, 6, and 12 months eGFR (r = 0.8929, 0.9294, 0.9320, and 0.8952, respectively). Preoperative relative renal function and total cortex margin volume were independent risk factors for decreasing postoperative renal function.

CONCLUSION

This precise volumetric assessment that includes the resected margin is an alternative to renal scintigraphy for predicting postoperative relative renal function. The healthy cortex margin volume calculated by the reconstruction technique is an independent risk factor of decreasing postoperative renal function.

Quality and Quantity in Kidney Cancer Surgery: The Role of Nonneoplastic Kidney and Kidney Volumetrics in Predicting Postoperative Renal Function

Objectives

To model renal function 2 years following radical nephrectomy with quantitative analyses using clinical, histopathologic, and renal composite cortical volumes (CCV).

Methods

This retrospective study involved an assessment of the nonneoplastic kidney tissue by three blinded nephropathologists using modified Banff 1997 criteria for renal allograft pathology. Volumetric image acquisition was obtained by three independent radiologists using preoperative imaging. A 2-year estimated glomerular filtration (eGFR) calculator was created.

Results

Among the 126 patients, median age was 60 years; median CCV, 398.1 cm3; preoperative eGFR, 77 mL/min/1.73 m2; and 2-year postoperative eGFR, 54 mL/min/1.73 m2. Of the subjects, 64% had hypertension, 26% diabetes, and 37% were smokers. Increasing age, glomerulopathy/sclerosis, tubulointerstitial scarring, and arteriosclerosis were statistically significantly and adversely associated with eGFR. Conversely, increasing CCV was associated with a higher eGFR.

Conclusions

Quantitative analysis of the nephrectomized kidney in conjunction with patient age can accurately predict renal function at 2 years.

The preoperative stratification of patients based on renal scan data is unable to predict the functional outcome after partial nephrectomy

INTRODUCTION

eGFR-categories are used to predict functional outcome after partial nephrectomy (PN); no study categorized patients according to preoperative renal scan (RS) data. Aim of the study was to evaluate if stratification of patients according to RS is a reliable method to predict minor/major loss of renal function after PN.

MATERIALS AND METHODS

We considered patients who underwent PN and RS pre-/post-PN for T1 tumor in our Institution (2007-2017). Demographics, perioperative and specifically functional data were analysed. On the basis of the baseline Split Renal Function (SRF), patients were stratified into risk-categories: 1) baseline operated-kidney SRF range 45-55%; 2) baseline operated-kidney SRF < 45%. Risk categories were analysed with postoperative functional outcome: postoperative operated-kidney SRF decrease below 90% of baseline was considered significant loss of function. Contingency tables and univariate/multivariate regression were analysed looking for independent factors of postoperative functional impairment.

RESULTS

224 patients were analysed, 125 (55.8%) maintained >90% of their baseline function. Worse probability of maintaining ≥90 baseline renal function was found in patients with Charlson's Comorbidity Index (CCI≥3) (p=0.004) and patients with PADUA score ≥8 (p=0.023). After stratification by baseline renal function, ischemia was the only independent factor: no effect on patients with poorer baseline renal function. Patients with baseline SRF 45-55% who did not experience ischemia had the highest probability to maintain ≥90% baseline SRF (p=0.028). Ischemia >25 minutes was detrimental (p=0.017).

CONCLUSIONS

Stratification of patients by SRF before PN is not a reliable predictor of renal functional outcome. Ischemia seems to scarcely influence patients with poorer renal function.

Are there limits of robotic partial nephrectomy? TRIFECTA outcomes of open and robotic partial nephrectomy for completely endophytic renal tumors

BACKGROUND

To compare the outcomes of robot-assisted (RAPN) and open partial nephrectomy (OPN) for completely endophytic renal tumors.

METHODS

Consecutive patients undergoing OPN or RAPN for entirely endophytic tumors in four high-volume centers between 2008 and 2016 were identified. Endophytic masses were identified based on sectional imaging. Patient characteristics and surgical outcome were compared using Mann-Whitney-U-test and chi-squared-tests. Uni- and multivariate analyses were performed to identify predictors of TRIFECTA achievement and excisional volume loss.

RESULTS

Out of 1128 patients, 10.9% (64) of RAPN and 13.9% (76) of OPN underwent surgery for entirely endophytic tumors. Operative time was longer for RAPN (169 vs 140 min, P = 0.03) while ischemia time was shorter (13 vs 18 min, P = 0.001). Complication rates were comparable (21% OPN vs 22% RAPN, P = 0.91) and TRIFECTA achievement was not different between the groups (68% OPN vs 75% RAPN, P = 0.39). In multivariate analyses type of surgery was not associated with TRIFECTA achievement or excisional volume loss. Here, only tumor complexity (OR 0.48, P = 0.001) and size (OR 1.01, P = 0.002) were independent predictors.

CONCLUSION

For entirely endophytic tumors, both RAPN and OPN offer good TRIFECTA achievement. This encourages the use of NSS even for these highly complex tumors using the surgeon's preferred approach.

Robotic Partial Nephrectomy in Patients with Chronic Kidney Disease: Objective Measurement of Short- and Long-Term Renal Functional Outcomes

BACKGROUND

Minimal literature informs the use of robotic partial nephrectomy (RPN) in patients with chronic kidney disease (CKD). Therefore, we evaluated the renal functional outcomes in CKD patients undergoing RPN.

METHODS

We reviewed a prospective database of patients undergoing RPN 2010 to 2015 and identified 182 patients who had preoperative and postoperative nuclear renal scintigraphy (at 2 and 12 months postop). Preoperative and 12-month postoperative eGFR (mL/min/1.73 m², by MDRD) were calculated. CKD was defined as eGFR ≤60 mL/min/1.73 m² (CKD stages III and IV). Changes in creatinine, eGFR, and split function on mercaptoacetyltriglycine (MAG)-3 scan were compared by baseline CKD status. Correlations between pre- and postoperative eGFR were calculated.

RESULTS

Of 182 patients, 30 (16.5%) had baseline CKD. Preoperative eGFR was 48.5 and 99.0 in CKD and non-CKD patients, respectively (p < 0.001). From preoperation to 12 months postoperation, eGFR decreased by 2.8 and 1.1 mL/min/1.73 m², respectively (p = 0.6). On MAG-3 scan, the contribution of the surgical kidney to overall renal function decreased by 5.0% and 4.8% (p = 0.9) in the CKD and non-CKD cohorts, respectively. When comparing renal scans at 2 and 12 months postoperation, in both groups the surgical kidney significantly recovered (both p < 0.001) and the patterns of kidney function recovery was similar in both groups (CKD +2.0%, non-CKD +1.4%, p = 0.6). On long-term follow-up (>2 years), eGFR did not change significantly in either the CKD or non-CKD group (-2.8 vs -1.1 mL/min/1.73 m², p = 0.6). On pathology, tumors were more frequently malignant in CKD vs non-CKD patients (93.3% vs 73.2%, p = 0.02) and of higher Fuhrman Grade (grade ≥3: 49.7% vs 28.1%, p < 0.001).

CONCLUSION

RPN is a reasonable treatment option in patients with CKD, as it did not lead to a greater decline in renal function contributed by the surgical kidney. The patterns of kidney function recovery after surgery are similar between patients with and without CKD.

Robot-assisted partial nephrectomy: systematic review of functional results

PURPOSE OF REVIEW

Various ischemia type during partial nephrectomy for renal cell cancer (RCC) resulted in different postoperative functional outcomes. Our objective was to systematically review the contemporary literature on robot-assisted partial nephrectomy (RPN) and investigate the association of ischemia type and tumor complexity with postoperative functional outcomes of the operated kidney and overall.

RECENT FINDINGS

Forty-five of the 99 reports identified were selected for qualitative analysis. All included studies were observational and nonrandomized. Overall, we found that patients undergoing RPN with zero ischemia and selective artery clamping had a lower decrease in glomerular filtration rates of the operated kidney in comparison to both warm and cold ischemia. This association seems also to play a role in patients with bilateral kidneys harboring complex tumors.

SUMMARY

Zero ischemia and selective artery clamping provide the best functional outcomes following robotic partial nephrectomy. This seems to be of particular relevance in patients with single kidney or tumors of high complexity. Whether these changes are statistically or clinically significant cannot be determined within this systematic review.

Assessing Time of Full Renal Recovery Following Minimally Invasive Partial Nephrectomy

OBJECTIVE

To assess renal function in the operated kidney at different time points post partial nephrectomy (PN) and establish the time in which optimal recovery occurs. Recovery of renal function post-PN has received significant attention. However, the optimal time to determine full recovery has not been clearly established.

MATERIALS AND METHODS

Renal function following minimally invasive (laparoscopic and robotic) PNs performed between 2002 and 2015 was reviewed. Patients included in this study had renal function assessed preoperatively as well as 3 days, 6-12 weeks, and 1 year post-PN, using a combination of estimated glomerular filtration rate (eGFR) from serum creatinine and relative renal uptake (RRU) from Tc99m-MAG3 renal scintigraphy. Together, eGFR and RRU provide the ipsilateral renal function (IRF) of the operated organ.

RESULTS

At 6-12 weeks postoperatively, percent preserved eGFR, RRU, and IRF (relative to preoperative baselines) were 92.1%, 83.3%, and 77.4% respectively. %IRF at 6-12 weeks was significantly improved from %IRF at 3 days postoperatively, but did not differ significantly from 1 year postoperatively. Furthermore, 89% of patients had RRU values at 6-12 weeks which differed by less than 5% from RRU values at 1 year.

CONCLUSION

Our data suggest that renal function recovery at 6-12 weeks was equivalent to long-term recovery at 1 year in the majority of post-PN patients. This has important implications for post-PN follow-up, particularly in assessing the functional outcomes utilizing novel minimally invasive PN strategies, as well as in planning staged procedures for bilateral synchronous renal masses.

Ipsilateral renal function preservation following minimally invasive partial nephrectomy: The effect of tumour characteristics and warm ischemic time

INTRODUCTION

The relative impact of preoperative and perioperative variables on renal function following partial nephrectomy (PN) is controversial. To further investigate, we assess the effects of tumour complexity, warm ischemic time (WIT), and volume of resected renal parenchyma on ipsilateral renal function (IRF) outcomes following minimally invasive PN.

METHODS

Of patients who underwent laparoscopic or robotic-assisted PN between 2002 and 2011 at our institution, 99 met our inclusion criteria. The effects of preoperative tumour complexity (using RENAL nephrometry score), perioperative WIT, and pathological tumour volumes on ipsilateral renal function preservation (%IRF) were analyzed. %IRF was defined as the proportion of postoperative to preoperative ipsilateral renal function calculated using MAG3 nuclear renography.

RESULTS

Increasing RENAL nephrometry score (RNS) and WIT were independently predictive of inferior %IRF at 6-12-week postoperative followup in univariate and multivariate analyses. Of RNS properties, masses that were endophytic, near the collecting system, or central in location were associated with inferior %IRF, with nearness to collecting system as the strongest predictor; however, RNS was no longer predictive of %IRF in cases requiring more than 30 minutes of WIT.

CONCLUSIONS

In renal masses amenable to resection by minimally invasive PN, longer WIT was the most important predictor of inferior %IRF. Although increasing RNS score influenced %IRF, the overall clinical significance of RNS is limited and should not influence operative decision-making in efforts to preserve renal function. Furthermore, small volumes of renal parenchyma can be safely resected without impairment of long-term IRF.

The impact of T1 renal tumor characteristics on baseline renal function in patients undergoing partial nephrectomy: A renal scan based objective assessment

INTRODUCTION AND OBJECTIVES

To objectively assess the impact of renal tumors characteristics and other measurable factors on baseline renal function in patient undergoing partial nephrectomy (PN).

METHODS

Patients who underwent laparoscopic PN for a T1 renal mass between 2012 and 2016 and who also had a mercapto-acetyltriglycine renal scan prior to surgery were retrieved from a single institution prospectively-collected database. Split renal function (SRF) and Effective Renal Plasma Flow (ERPF) for both the operated kidney and the unaffected contralateral were calculated. Patient demographics and tumor characteristics (e.g. size, location and; nephrometry score) were assessed. Renal function of both the operated and the unaffected; contralateral kidney were compared. Statistical analysis was performed by using Statistica 8.0 (StatSoft).

RESULTS

227 patients were deemed eligible and included in the analysis. Univariable analysis showed a significant impact of age-adjusted CCI (p = 0.027), hypertension (p = 0.031) and age (p < 0.001) on operated kidney ERPF. Gender (p = 0.011), hypertension (p = 0.042), CCI (both standard and age-adjusted, p = 0.021 and = 0.003, respectively) and age (p < 0.001) were significantly; associated with contralateral unaffected kidney ERPF. Multivariable analysis confirmed age (p < 0.001) and hypertension (p < 0.021) as independent factors in both the operated and the unaffected kidney.

CONCLUSIONS

Characteristics of the renal mass (including nephrometry score and size) seem to have no clinically relevant impact on baseline renal function in patients undergoing partial nephrectomy for cT1 renal tumors. Age, hypertension and co-morbidities confirm to represent un-modifiable significant factors influencing baseline renal function.

The Synergistic Influence of Ischemic Time and Surgical Precision on Acute Kidney Injury After Robotic Partial Nephrectomy

OBJECTIVE

To examine the dynamic and potentially synergistic influence of warm ischemia time (WIT) and excisional volume loss (EVL) on predicted rates of postpartial acute kidney injury (AKI) across a range of tumor complexities, and to investigate whether these modifiable variables sensitize the kidney to each other's damaging influence.

MATERIALS AND METHODS

We retrospectively reviewed 1245 patients between 2006 and 2016 with bilateral kidneys and enhancing renal masses in our single-institution robotic partial nephrectomy (PN) database. EVL was calculated as the difference between specimen and tumor volume based on pathologic measurements. Multivariate logistic regressions, followed by marginal effects, were run to examine the interaction of ischemia type, EVL, and radius, exophytic/endophytic properties, nearness of deepest tumor portion to collecting system or sinus, anterior/posterior and location relative to polar line score on rates of AKI.

RESULTS

We found a significant interaction effect of WIT and log EVL on predicted AKI (P < .001). Each doubling of EVL caused a 4.03% and 8.46% increased probability of AKI for WIT of <25 and >25 minutes, respectively. At an EVL of >5.5 cm³, prolonged WIT had statistically greater odds of causing AKI. These predicted effects on AKI were amplified for increasing radius, exophytic/endophytic properties, nearness of deepest tumor portion to collecting system or sinus, anterior/posterior and location relative to polar line scores (P < .001).

CONCLUSION

Although the adverse functional effects of WIT and parenchymal volume loss during PN have previously been described in isolation, our findings suggest that their influence on AKI is synergistic, especially in complex tumors. As such, additional attention should be given to limiting warm ischemia and maximizing surgical precision to avoid a "double hit" on postoperative renal function.

Ischemia and Functional Recovery from Partial Nephrectomy: Refined Perspectives

BACKGROUND

Nephron mass preservation is a key determinant of functional outcomes after partial nephrectomy (PN), while ischemia plays a secondary role. Analyses focused specifically on recovery of the operated kidney appear to be most informative, yet have only included limited numbers of patients.

OBJECTIVE

To evaluate the relative impact of parenchymal preservation and ischemia on functional recovery after PN using a more robust cohort allowing for more refined perspectives about ischemia.

DESIGN, SETTING, AND PARTICIPANTS

A total of 401 patients managed with PN with necessary studies were analyzed for function and nephron mass preserved specifically within the kidney exposed to ischemia.

INTERVENTION

PN.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The nephron mass preserved was measured from computed tomography scans <2 mo before and 3-12 mo after PN. Patients with two kidneys were required to have nuclear renal scans within the same timeframes. Recovery from ischemia was defined as the percent function preserved normalized by the percent nephron mass preserved. Pearson correlation was used to evaluate relationships between functional recovery and nephron mass preservation or ischemia time. Multivariable linear regression assessed predictors for recovery from ischemia.

RESULTS AND LIMITATIONS

The median tumor size was 3.5cm and the median RENAL score was 8. Cold and warm ischemia were utilized in 151 and 250 patients, and the median ischemia time was 27 and 21min, respectively. The function preserved was strongly correlated with nephron mass preserved(r=0.63; p<0.001). Median recovery from ischemia was significantly higher for hypothermia (99% vs 92%; p<0.001) and remained consistently strong even with longer duration. Multivariable analysis demonstrated that recovery from ischemia, which normalizes for nephron mass preservation, was significantly associated with ischemia type and duration (both p<0.05). However, each additional 10min of warm ischemia was associated with only a 2.5% decline in recovery from ischemia. Limitations include the retrospective design.

CONCLUSIONS

Our data suggest that functional recovery from clamped PN is most reliable with hypothermia. Longer intervals of warm ischemia are associates with reduced recovery; however, incremental changes are modest and may not be clinically significant in patients with a normal contralateral kidney.

PATIENT SUMMARY

Functional recovery after clamped partial nephrectomy is primarily dependent on preservation of nephron mass. Recovery is most reliable when hypothermia is applied. Longer intervals of warm ischemia are associated with reduced recovery; however, the incremental changes are modest.

Selective arterial clamping does not improve outcomes in robot-assisted partial nephrectomy: a propensity-score analysis of patients without impaired renal function

OBJECTIVES

To assess the benefit of selective arterial clamping (SAC) as an alternative to main renal artery clamping (MAC) during robot-assisted partial nephrectomy (RAPN) in patients without underlying chronic kidney disease (CKD).

PATIENTS AND METHODS

Our study cohort comprised 665 patients without impaired renal function undergoing MAC (n = 589) or SAC (n = 76) during RAPN from four medical institutions in the period 2008-2015. We compared complication rates, positive surgical margin (PSM) rates, and peri-operative and intermediate-term renal functional outcome between 132 patients undergoing MAC and 66 undergoing SAC after 2-to-1 nearest-neighbour propensity-score matching for age, sex, body mass index, RENAL nephrometry score, tumour size, baseline estimated glomerular filtration rate (eGFR), American Society of Anesthesiologists (ASA) score, Charlson comorbidity index (CCI) and warm ischaemia time (WIT).

RESULTS

In propensity-score-matched patients, PSM (5.7 vs 3.0%; P = 0.407) and complication rates (13.8 vs 10.6%; P = 0.727) did not differ between the MAC and SAC groups. The incidence of acute kidney injury for MAC vs SAC (25.0 vs 32.0%; P = 0.315) within the first 30 days was similar. At a median follow-up of 7.5 months, the percentage reduction in eGFR (-9.3 vs -10.4%; P = 0.518) and progression to CKD ≥ stage 3 (7.2 vs 8.5%; P = 0.792) showed no difference.

CONCLUSIONS

Our study findings show no difference in PSM rates, complication rates or intermediate-term renal functional outcomes between patients with unimpaired renal function who underwent SAC vs those who underwent MAC. When expected WIT is low, the routine use of SAC may not be necessary. Further studies will need to determine the role of SAC in patients with a solitary kidney or with significantly impaired renal function.

Impact of ischaemia time on renal function after partial nephrectomy: a systematic review

OBJECTIVE

To assess the impact of ischaemia on renal function after partial nephrectomy (PN).

MATERIALS AND METHODS

A literature review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. In January 2015, the Medline and Embase databases were systematically searched using the protocol ('warm ischemia'[mesh] OR 'warm ischemia'[ti]) AND ('nephrectomy'[mesh] OR 'partial nephrectomy'[ti]). An updated search was performed in December 2015. Only studies based on a solitary kidney model or on a two-kidney model but with assessment of split renal function were included in this review.

RESULTS

Of the 1119 studies identified, 969 abstracts were screened after duplicates were removed: 29 articles were finally included in this review, including nine studies that focused on patients with a solitary kidney. None of the nine studies adjusting for the amount of preserved parenchyma found a negative impact of warm ischaemia time on postoperative renal function, unless this was extended beyond a 25-min threshold. The quality and the quantity of preserved parenchyma appeared to be the main contributors to postoperative renal function.

CONCLUSION

Currently, no evidence supports that limited ischaemia time (i.e. ≤25 min) has a higher risk of reducing renal function after PN compared to a 'zero ischaemia' technique. Several recent studies have suggested that prolonged warm ischaemia (>25-30 min) could cause an irreversible ischaemic insult to the surgically treated kidney.

Comparison of Renal Function between Robot-Assisted and Open Partial Nephrectomy as Determined by Tc 99m-DTPA Renal Scintigraphy

We compared postoperative renal function impairment between patients undergoing robot-assisted partial nephrectomy (RAPN) and those undergoing open partial nephrectomy (OPN) by using Tc-99m diethylenetriaminepentaacetic acid (DTPA) renal scintigraphy. Patients who underwent partial nephrectomy by a single surgeon between 2007 and 2013 were eligible and were matched by propensity score, based on age, tumor size, exophytic properties of tumor, and location relative to the polar lines. Of the 403 patients who underwent partial nephrectomy, 114 (28%) underwent RAPN and 289 (72%) underwent OPN. Mean follow-up duration was 35.2 months. Following propensity matching, there were no significant differences between the two groups in tumor exophytic properties (P = 0.818) or nephrometry score (P = 0.527). Renal ischemic time (24.4 minutes vs. 17.8 minutes, P < 0.001) was significantly longer in the RAPN group than in the OPN group, while the other characteristics were similar. Multivariate analysis showed that greater preoperative renal unit function (P = 0.011) and nephrometry score (P = 0.041) were independently correlated with a reduction in glomerular filtration rate. The operative method did not correlate with renal function impairment (P = 0.704). Postoperative renal function impairment was similar between patients who underwent OPN and those who underwent RAPN, despite RAPN having a longer ischemic time.

Achievement of trifecta in minimally invasive partial nephrectomy correlates with functional preservation of operated kidney: a multi-institutional assessment using MAG3 renal scan

PURPOSE

To validate and compare the values of "MIC" and "trifecta" as predictors of operated kidney functional preservation in a multi-institutional cohort of patients undergoing minimally invasive PN.

METHODS

We retrospectively reviewed records of consecutive cases of minimally invasive PN performed for cT1 renal masses in 4 centers from 2009 to 2013. Inclusion criteria consisted of availability of a renal scan obtained within 2 weeks prior to surgery and follow-up renal scan 3-6 months after the surgery. The primary endpoint of the study was to compare the degree of ipsilateral renal function preservation assessed by MAG3 renal scan in relation to achievement of MIC and trifecta.

RESULTS

Total of 351 patients met our inclusion criteria. The rates of trifecta achievement for cT1a and cT1b tumors were 78.9 and 60.6 %, respectively. The rate of MIC achievement for cT1a tumors and cT1b tumors was 60.3 and 31.7 %, respectively. On multivariable linear regression model, only the degree of tumor complexity assessed by R.E.N.A.L nephrometry score [coefficient B -1.8 (-2.7, -0.9); p < 0.0001] and the achievement of trifecta [coefficient B 6.1 (2.4,9.8); p = 0.014] or MIC (coefficient B 7.2 (3.8,0.6); p < 0.0001) were significant clinical factors predicting ipsilateral split function preservation.

CONCLUSIONS

Achievement of both MIC and "trifecta" is associated with higher proportion of split renal function preservation for cT1 tumors after minimally invasive PN. Thus, these outcome measures can be regarded not only as markers of surgical quality, but also as reliable surrogates for predicting functional outcome in the operated kidney.

Review of robot-assisted partial nephrectomy in modern practice

Partial nephrectomy (PN) is currently the standard treatment for T1 renal tumors. Minimally invasive PN offers decreased blood loss, shorter length of stay, rapid convalescence, and improved cosmesis. Due to the challenges inherent in laparoscopic partial nephrectomy, its dissemination has been stifled. Robot-assisted partial nephrectomy (RAPN) offers an intuitive platform to perform minimally invasive PN. It is one of the fastest growing robotic procedures among all surgical subspecialties. RAPN continues to improve upon the oncological and functional outcomes of renal tumor extirpative therapy. Herein, we describe the surgical technique, outcomes, and complications of RAPN.