A low RENAL Nephrometry Score can avoid the need for the intraoperative insertion of a ureteral catheter in robot-assisted partial nephrectomy.

BACKGROUND: Intraoperative urinary collecting system entry (CSE) in robot-assisted partial nephrectomy (RAPN) may cause postoperative urinary leakage and extend the hospitalization. Therefore, identifying and firmly closing the entry sites are important for preventing postoperative urine leakage. In RAPN cases expected to require CSE, we insert a ureteral catheter and inject dye into the renal pelvis to identify the entry sites. We retrospectively analyzed the factors associated with intraoperative CSE in RAPN and explored the indications of intraoperative ureteral catheter indwelling in RAPN. METHODS: Of 104 Japanese patients who underwent RAPN at our institution from August 2016 to March 2020, 101 were analyzed. The patients were classified into CSE and non-CSE groups. The patients' background characteristics, RENAL Nephrometry Score (RNS), and surgical outcomes were analyzed. RESULTS: Intraoperative CSE was observed in 41 patients (41%). The CSE group had a significantly longer operative time, console time, ischemic time, and hospital stay than the non-CSE group. In a multivariable analysis, the N-score (odds ratio [OR] = 3.9, P < 0.05) and RNS total score excluding the L-score (OR = 3.1, P < 0.05) were associated with CSE. In a logistic regression analysis, CSE showed a moderate correlation with the RNS total score excluding the L-score (AUC 0.848, cut-off 5, sensitivity 0.83, specificity 0.73). CONCLUSION: A ureteral catheter should not be placed in patients with an RNS total score (excluding the L-score) of ≤ 4.

Predictors of renal function after open and robot-assisted partial nephrectomy: A propensity score-matched study.

OBJECTIVE: To investigate parameters predicting short- and long-term renal function after open partial nephrectomy and robot-assisted partial nephrectomy. METHODS: Medical records of 896 patients who underwent open partial nephrectomy or robot-assisted partial nephrectomy from 2004 to 2017 at a single large-volume institution were retrospectively reviewed. Propensity score matching of open partial nephrectomy and robot-assisted partial nephrectomy group was carried out with a ratio of 1:1. Postoperative outcomes were compared, and multivariate logistic regression was carried out to identify the parameters influencing acute kidney injury and chronic kidney disease progression. RESULTS: No significant differences in preoperative characteristics were observed between the two study groups after matching. Robot-assisted partial nephrectomy was significantly associated with a longer warm ischemic time (P < 0.001) yet, estimated blood loss, positive surgical margin, rates of major postoperative complications and chronic kidney disease progression were significantly lower in the robot-assisted partial nephrectomy group (P < 0.001, 0.033, <0.001, <0.001, and 0.005, respectively). Multivariate analysis showed robot-assisted partial nephrectomy was more favorable than open partial nephrectomy in terms of preserving renal function. Patients with a higher baseline estimated glomerular filtration rate were significantly associated with a greater risk of acute kidney injury (odds ratio 1.036; 95% confidence interval 1.021-1.052; P < 0.001), but a decreased risk of chronic kidney disease progression (odds ratio 0.975; 95% confidence interval 0.955-0.994; P = 0.011). Other independent predictors of chronic kidney disease progression were warm ischemic time (P = 0.025), age (P = 0.035), body mass index (P = 0.041) and diabetes mellitus (P = 0.035). CONCLUSIONS: Baseline estimated glomerular filtration rate, warm ischemic time and surgery type are independent predictors of both acute kidney injury and chronic kidney disease progression. Robot-assisted partial nephrectomy is more favorable than open partial nephrectomy for reducing estimated blood loss, positive surgical margin, major postoperative complications and renal function preservation.

The effectiveness of RENAL nephrometry score in ablated renal tumors via radiofrequency ablation or cryoablation

Background/aim: This study aimed to evaluate the clinical efficacy of radiofrequency ablation (RFA) and cryotherapy and to scrutinize the therapeutic success of the RENAL (radius, exophytic/endophytic, nearness to collecting system, anterior/posterior, and location) nephrometry score in terms of possible complications and the predictive status of oncological results. Materials and methods: Forty-five patients with biopsy-proven renal cell carcinomas (32 males, 13 females) treated with RFA and cryotherapy were included. Patients were 22­90 years old (average: 59.2 years). Statistical analyses were performed using SPSS for Windows. Results: A total of 79 lesions with dimensions varying between 0.9 and 4.5 cm (average: 2.2 cm) were ablated. Complete ablation was achieved for 72 (91.1%) lesions. Six repeat RFA sessions were applied for 4 (5%) lesions with residue/recurrence. The average RENAL nephrometry scores of lesions that underwent complete ablation and those that developed residue/recurrence were 6.3 and 7.7, respectively. The average recurrence-free survival time was 34.8 months (range: 3­55 months), while it was 44.6 months (range: 6­55 months) for cryotherapy and 28.6 months (range: 3­50 months) for RFA. Conclusion: Ablative therapies are minimally invasive and effective methods for treating small renal tumors. RENAL nephrometry scoring is a valuable system for standardizing renal tumors and evaluating the success of ablative therapies, possible complications, and oncological results.

Robot-assisted partial nephrectomy for large renal masses: a multi-institutional series.

OBJECTIVES: To compare peri-operative outcomes after robot-assisted partial nephrectomy (RAPN) for cT2a (7 to <10 cm) to cT1 tumours. MATERIALS AND METHODS: Patients with a cT1a (n = 1 358, 76.4%), cT1b (n = 379, 21.3%) or cT2a (n = 41, 2.3%) renal mass were identified from a multi-institutional RAPN database. Intra- and postoperative outcomes were compared for cT2a masses vs cT1a and cT1b masses using multivariable regression models (linear, logistic, Poisson etc.), adjusting for operating surgeon and a modified R.E.N.A.L. nephrometry score that excluded the radius component. RESULTS: The median sizes for cT1a, cT1b and cT2a tumours were 2.5, 5.0 and 8.0 cm, respectively (P < 0.001) with modified R.E.N.A.L. nephrometry scores being 6.0, 6.5 and 7.0, respectively (cT1a, P < 0.001; cT1b, P = 0.105). RAPN for cT2a vs cT1a masses was associated with a 12% increase in operating time (P < 0.001), a 32% increase in estimated blood loss (P < 0.001), a 7% increase in ischaemia time (P = 0.008), a 3.93 higher odds of acute kidney injury at discharge (95% confidence interval [CI] 1.33, 8.76; P = 0.009) and a higher risk of recurrence (hazard ratio [HR] 10.9, 95% CI 1.31, 92.2; P = 0.027). RAPN for cT2a vs cT1b masses was associated with a 12% increase in blood loss (P = 0.036), a 5% increase in operating time (P = 0.062) and a marginally higher risk of recurrence (HR 11.2, 95% CI 0.77, 11.5; P = 0.059). RAPN for cT2a tumours was not associated with differences in complications (cT1a, P = 0.535; cT1b, P = 0.382), positive margins (cT1a, P = 0.972; cT1b, P = 0.681), length of stay (cT1a, P = 0.507; cT1b, P = 0.513) or renal function decline up to 24 months post-RAPN (cT1a, P = 0.124; cT1b, P = 0.467). CONCLUSION: For T2a tumours RAPN is a feasible treatment option in a select patient population when performed by experienced surgeons in institutions equipped to manage postoperative complications. Although RAPN was associated with greater blood loss and longer operating and ischaemia time in T2a tumours, it was not associated with greater complication or positive surgical margin rates compared with T1 tumours. Renal function preservation rates were equivalent for up to 24 months postoperatively; however, 12-month recurrence-free survival was significantly lower in the T2a group. Extended follow-up is required to further evaluate long-term survival.

Robotic and open partial nephrectomy for complex renal tumors: a matched-pair comparison with a long-term follow-up.

OBJECTIVES: To compare the surgical, functional and oncological outcomes of patients undergoing robotic partial nephrectomy (RPN) or open partial nephrectomy (OPN) for moderately or highly complex tumors (RENAL nephrometry score ≥7). METHODS: A retrospective, matched-pair analysis was performed for 380 patients who underwent either RPN (n = 190) or OPN (n = 190) for a complex renal mass in different institutions. Surgical data, pathological variables, complications and functional and oncological outcomes were reviewed. RESULTS: RPN is associated with less estimated blood loss (EBL) (196.8 vs 240.8 ml; p < 0.001), shorter length of hospital stay (7.8 vs 9.2 days; p < 0.001) and lower rate of postoperative complications (15.8 vs 28.9 %; p = 0.002). Patients undergoing RPN required more direct cost. In multivariable models, surgical approach was the significant predictor for the occurrence of postoperative minor complications and postoperative wound pain. Median follow-up for RPN and OPN was 49 months and 52 months, respectively. The decline of estimated glomerular filtration at the last available follow-up (RPN: 8.7 %; OPN: 10 %) was similar (p = 0.125). The 5-year recurrence-free survival rate was 95.1 % for RPN and 92.7 % for OPN (p = 0.48). CONCLUSIONS: RPN provides acceptable and comparable results in terms of perioperative, functional and oncological outcomes compared to OPN for complex renal tumors with RENAL score ≥7. Moreover, RPN is a less invasive approach with the benefit of shorter length of hospital stay, less EBL and lower rate of postoperative complications.

Impacts of Complete Endophytic Renal Tumors on Surgical, Functional, and Oncological Outcomes of Robot-Assisted Partial Nephrectomy.

Objective: Complete endophytic renal tumors (CERTs) are the most challenging for robot-assisted partial nephrectomy (RAPN). This study aimed to determine the impact of CERT on outcomes of RAPN. Methods: All RAPN cases for localized renal tumor undertaken at Yokohama City University Hospital between 2016 and 2023 were enrolled. Tumor characteristics and surgical, functional, and oncologic outcomes of RAPN were compared between CERT and non-CERT groups. Results: Consecutive 666 patients were enrolled, and 76 (11.4%) were identified as CERT (3 points of "E" score). CERT showed smaller tumor diameters (p < 0.001), more predominant hilar tumor (p = 0.029), higher "N" scores (p < 0.001) and "L" scores (p = 0.006) than non-CERT. The CERT group showed longer warm ischemia times (p < 0.001), more frequent positive surgical margins (p = 0.028), and relatively lower trifecta achievement rates (p = 0.101) than the non-CERT group. In multivariable analysis, the CERT was an independent predictor for trifecta achievement but not for pentafecta achievement. Conclusions: CERT was associated with longer warm ischemia time, positive surgical margin, and lower trifecta achievement, but not with surgical complication and pentafecta achievement in RAPN. This study suggested that CERT had limited influence on long-term renal functional preservation; however, it had strong impacts on short-term surgical outcome.

Predictive factors of renal function after robot-assisted partial nephrectomy in clinical T1b tumors.

Robot-assisted partial nephrectomy (RAPN) has been shown to be a safe and effective method for treatment of small renal tumors, including clinical T1b renal cell carcinoma (RCC); however, the impact of RAPN for cT1b renal tumors on renal function is not well understood. In this retrospective study, 50 patients who underwent RAPN for cT1b renal tumors were evaluated for pre- and post-operative renal function and perioperative clinical factors. Renal function was assessed using the estimated glomerular filtration rate (eGFR) at baseline and on postoperative days (POD) 1, 7, 30, and 180.A significant renal functional decline was defined as ≥ 15% reduction in eGFR at POD180 compared with eGFR at baseline. Logistic regression analyses were used to identify risk factors for renal function decline, including age, sex, RENAL nephrometry score, operative time, and estimated blood loss. The median patient age was 62 years, and the median tumor diameter and RENAL nephrometry score were 44 mm (IQR 43-50) and 8 (IQR 7-9), respectively. Of these patients, 16 (36%) showed a significant renal functional decline at POD 180. In the multivariate analysis, the L component of the RENAL nephrometry score and an estimated blood loss of 200 mL or more were identified as significant risk factors for renal functional decline. These findings suggest that the preoperatively definable L component of the RENAL nephrometry score and intraoperative blood loss, which may be modifiable factors, play significant roles in post-RAPN renal function decline.

Renal tumour nephrometry score does not correlate with the risk of radiofrequency ablation complications.

OBJECTIVES: To assess whether the R.E.N.A.L. nephrometry score (consists of [R]adius [tumour size as maximal diameter], [E]xophytic/endophytic properties of the tumour, [N]earness of tumour deepest portion to the collecting system or sinus, [A]nterior [a]/posterior [p] descriptor and the [L]ocation relative to the polar line) is associated with complication risk in patients that have radiofrequency ablation (RFA) for small renal masses (SRMs). To evaluate a standardised system for predicting complication risks which has not been studied. PATIENTS AND METHODS: We reviewed the records of all patients who underwent RFA at our institution between May 2001 and May 2011. RFA was performed using a temperature-based system and a 25-G nine-tine array needle probe. Patients with preoperative imaging available for R.E.N.A.L. nephrometry scoring were included. R.E.N.A.L. composite scores, tertile stratification and preoperative patient characteristics were analysed for significance in relation to complications. Complications were defined using the Clavien-Dindo classification system. RESULTS: In all, 199 patients had preoperative R.E.N.A.L. nephrometry scores available; 170 underwent percutaneous RFA and 29 laparoscopic RFA. The mean (range) American Society of Anesthesiologists (ASA) score was 2.6 (1-4). The mean (range) tumour size was 2.4 (0.7-5.4) cm. Overall, 14 complications were identified; 10 minor (Clavien I-II) and four major (Clavien III-IV). There was no significant association between complications and R.E.N.A.L. nephrometry score, R.E.N.A.L. nephrometry tertiles, tumour diameter, tumour location or ASA score (P > 0.05). CONCLUSION: R.E.N.A.L. nephrometry scoring fails to predict complications of RFA for SRMs when using a temperature-based nine-tine array probe.

Comparison of perioperative outcomes of robotic vs. laparoscopic partial nephrectomy for renal tumors with a RENAL nephrometry score ≥7: A meta-analysis.

Introduction: To compare the perioperative outcomes of robotic partial nephrectomy (RPN) vs. laparoscopic partial nephrectomy (LPN) for complex renal tumors with a RENAL nephrometry score ≥7. Methods: We searched PubMed, EMBASE and the Cochrane Central Register for studies from 2000 to 2020 to evaluate the perioperative outcomes of RPN and LPN in patients with a RENAL nephrometry score ≥7. We used RevMan 5.2 to pool the data. Results: Seven studies were acquired in our study. No significant differences were found in the estimated blood loss (WMD: 34.49; 95% CI: -75.16-144.14; p = 0.54), hospital stay (WMD: -0.59; 95% CI: -1.24-0.06; p = 0.07), positive surgical margin (OR: 0.85; 95% CI: 0.65-1.11; p = 0.23), major postoperative complications (OR: 0.90; 95% CI: 0.52-1.54; p = 0.69) and transfusion (OR: 0.72; 95% CI: 0.48-1.08; p = 0.11) between the groups. RPN showed better outcomes in the operating time (WMD: -22.45; 95% CI: -35.06 to -9.85; p = 0.0005), postoperative renal function (WMD: 3.32; 95% CI: 0.73-5.91; p = 0.01), warm ischemia time (WMD: -6.96; 95% CI: -7.30--6.62; p < 0.0001), conversion rate to radical nephrectomy (OR: 0.34; 95% CI: 0.17 to 0.66; p = 0.002) and intraoperative complications (OR: 0.52; 95% CI: 0.28-0.97; p = 0.04). Discussion: RPN is a safe and effective alternative to LPNs for or the treatment of complex renal tumors with a RENAL nephrometry score ≥7 with a shorter warm ischemic time and better postoperative renal function.

Image-guided percutaneous cryoablation of T1b renal cell carcinomas in patients with comorbidities.

PURPOSE: To investigate the influence of comorbidities and tumor characteristics on outcomes following percutaneous cryoablation (PCA) of T1b renal cell carcinoma (RCC). MATERIALS AND METHODS: Age-adjusted Charlson comorbidity index (ACCI); standardized system for quantitating renal tumor size, location, and depth (RENAL nephrometry score [RNS]); and local tumor control and survival were retrospectively investigated in 28 patients who underwent PCA for stage T1b RCC. Risk factors for elevated serum creatinine levels were also investigated. RESULTS: Complete ablation was obtained in 27 of 28 patients. Two cases of metastasis were observed; one patient died 12 months after PCA. Overall survival at 5 years was 79.1%, with a mean follow-up of 42.0 ± 16.0 months. Local tumor control was not correlated with the ACCI and RNS. Worsening renal function 3 months after PCA was observed in ten patients, and it correlated with the presence of single kidneys (7/28 patients; p = 0.023). Significant worsening of renal function continued until 1 year after PCA (p = 0.013). Having a single kidney was a risk factor for worsened renal function after PCA (odds ratio, 8.00; 95% confidence interval 1.170-54.724). CONCLUSION: PCA for T1b RCC confers positive local tumor control regardless of comorbidities and tumor characteristics.

RENAL nephrometry score: Predicting perioperative outcomes following open partial nephrectomy.

BACKGROUND: Partial nephrectomy has emerged as a standard treatment for small renal masses offering oncologic control equivalent to radical nephrectomy, with preservation of renal function and evidence for equivalent survival. In this study, we evaluated RENAL nephrometry score (RNS) in predicting perioperative outcomes in patients with partial nephrectomy. MATERIALS AND METHODS: This was a prospective observational study conducted from February 2016 to August 2017 which included patients who underwent partial nephrectomy. The patients were divided into three groups depending on the complexity scores (low, moderate, and high). Tumors were assigned RNS and tumor-node-metastasis staging of the clinically malignant tumors was done. Blood loss, warm ischemia time (WIT), and surgical complications were assessed. RESULTS: A total of 20 patients underwent open partial nephrectomy during the study. There were 4 (20%) low, 11 (55%) moderate, and 5 (25%) high-complexity lesions. Blood loss was significantly different in three groups. All the cases in high-complexity group were performed with clamping the renal vessels with a mean WIT of 29 min. The overall complication rates were significantly different between the groups (P = 0.007); however, majority of the complications were low grade (Grades I and II) and were managed conservatively. CONCLUSION: In the present study, RNS was correlated with predicting surgical access route, need for clamping during partial nephrectomy, blood loss, decrease in glomerular filtration rate of operated kidneys, postoperative complications, and tumor grade.

Nephrometry score correlated with tumor proliferative activity inT1 clear cell renal cell carcinoma.

OBJECTIVE: To evaluate the association between the RENAL nephrometry score (RNS) and tumor proliferative activity assessed by immunohistochemistry in patients with localized renal cell carcinoma. METHODS: The current study included 145 pathological T1 (pT1) clear cell renal cell carcinomas (ccRCC). Tumor proliferative activity was assessed with the Ki67 index and microvessel density (MVD). RNS was retrospectively assessed in the present study. We divided patients into 3 groups according to RNS (RNS 4-6: low-complexity, 7-9: moderate complexity, and 10-12: high-complexity tumors) and compared the Ki67 index as well as MVD among the 3 groups. The association between the Ki67index/MVD and each component (R, E, N, A, L, h) was also evaluated. RESULTS: There were 56 low, 84 moderate, and 5 high-complexity tumors. The median Ki67 index of all tumors was 5.34% (interquartile range: 3.28-8.57). The median Ki67 index of low, moderate, and high-complexity tumors was 3.97%, 6.39%, and 11.27%, respectively, with a significant difference among the 3 groups (Kruskal-Wallis test, P = 0.0004). On the other hand, the median MVD of low, moderate, and high-complexity tumors was 14.11%, 14.42%, and 21.22%, respectively, and there were no significant differences among the 3 groups. In terms of each RNS component, there were significant differences in the Ki67 index among the 3 groups in N (P = 0.0101) and L (P = 0.0280) components, respectively. CONCLUSIONS: The revealed association between RNS and the Ki67 index in pT1 clear cell renal cell carcinomas further supports the previous findings that the anatomy of renal cell carcinoma is associated with the malignant potential of localized clear cell renal cell carcinoma, which may provide additional information for treatment decision.

Robotic versus open partial nephrectomy for highly complex renal masses: Comparison of perioperative, functional, and oncological outcomes.

INTRODUCTION: We aimed to compare perioperative, functional and oncological outcomes between robot-assisted partial nephrectomy (RAPN) and open partial nephrectomy (OPN) for highly complex renal tumors (R.E.N.A.L. nephrometry Score > 9). METHODS: A retrospective review of 1,497 patients who consecutively underwent partial nephrectomy at a single academic tertiary center between 2008 and 2016 was performed to get data about patients who underwent RAPN and OPN for renal masses with RENAL score > 9. Baseline, perioperative, functional, and oncological outcomes were compared. RESULTS: Two hundred and three RAPN and 76 OPN were extracted. Patients' demographics and tumors' characteristics were comparable between the groups. Blood loss (200 vs. 300 cc, P < 0.0001), intraoperative transfusion rates (3% vs. 15.8%, P < 0.001), and length of stay (3 vs. 5 days, P < 0.01) were lower for RAPN. A significant decrease in estimated glomerular filtration rate was observed from preoperative to postoperative period, regardless the approach (OPN, P = 0.026 vs. RAPN, P = 0.014). Conversion to radical nephrectomy was 7.8% and 5.9% for OPN and RAPN, respectively. At multivariable regression, open approach was predictive of intraoperative transfusion and reoperation. Overall actuarial rate of recurrence or metastasis was 4.3%, with 3 cancer-related deaths occurring after a median follow-up of 25 months. No differences were found between the groups. CONCLUSION: In our large single-institutional series of patients who underwent partial nephrectomy for highly complex renal tumors, robotic approach appeared to be a valuable alternative to OPN, with the advantages of reduced blood loss, ischemia time, transfusions rate, and length of stay.

Will the kidney function be reduced in patients with renal cell carcinoma following laparoscopic partial nephrectomy? Baseline eGFR, warm ischemia time, and RENAL nephrometry score could tell.

OBJECTIVES: To describe the natural history of kidney function following partial nephrectomy (PN) for patients with renal cell carcinoma (RCC), and to identify independent predictors of whether patients with RCC will retain renal function unchangeable or even increased and develop functional impairment of ≧25% post-PN. PATIENTS AND METHODS: We performed a retrospective analysis of 337 cases involving patients diagnosed with RCC of pT1-2N0M0 who underwent laparoscopic PN, the primary endpoints included the stabilization or increase in postoperative estimated glomerular filtration rate (eGFR) compared to the preoperative level and eGFR impairment of ≧25% following surgery. We plotted the trajectory of each patient's eGFR measurement starting from their first postoperative day to the last follow-up time post-PN and used moving average method to look at trends of eGFR changing. A logistic regression model was then applied to identify associations between clinical and surgical characteristics with eGFR outcomes. RESULTS: Patients were of an average age of 51.4 years and all were Chinese descent. The cohort was also primarily male (69.1%). One hundred ninety seven (58.5%) had eGFR ≧90 ml/min/1.73 m2, while 140 (41.5%) had an eGFR of 60 to 90 ml/min/1.73 m2 prior to the operation. All patients underwent minimally invasive PN with warm ischemia, with 64.1% (216/337) receiving laparoscopic surgery, and 35.9% (121/337) receiving robot-assisted laparoscopic surgery. On average, patients experienced a mean eGFR decrease of 23.8% immediately post-PN, followed by a slight increase and stabilization, with a mean 15.5% decline after 1 year. Twenty four percent (81/337) experienced GFR impairment of ≧25% over a median 10.0-month follow-up time period, while 29.1% (99/337) patients retained eGFR unchangeable or increased post-PN. And higher preoperative eGFR, longer warm ischemia time, and more complexity lesions (higher renal nephrometry score ) were found to be independently associated with higher chance of functional impairment of ≧25% and lower chance of eGFR stabilization post-PN. CONCLUSION: Although, majority of patients experienced decline of renal function post-PN, functional outcomes of eGFR unchangeable and increased were also seen, and baseline total eGFR, WIT as well as RENAL nephrometry score were determined to be independent predictors of those renal functional outcomes.

Predicting trifecta outcomes after robot-assisted nephron-sparing surgery: Beyond the nephrometry score.

Purpose: RENAL nephrometry score (RNS) was devised for deciding the approach for renal tumors. It is increasingly used in predicting perioperative outcomes with variable results. The actual difficulty encountered during surgery depends on a number of other variables. The main purpose of this prospective study was to identify these variables which are not addressed by current RNS. Materials and Methods: Forty-nine patients undergoing robotic nephron sparing surgery from January 2015 onward were included. RNS was calculated from the imaging. Operating surgeon rated each surgery on a Likert scale of 0-4 after the completion of the procedure. The questionnaire was pre-validated in 5 cases before administration. The correlation between the surgeon rating and RNS with perioperative parameters and trifecta outcomes were calculated. Results: Forty-seven percent surgeries were rated easy, and 53.0% were rated as difficult. Surgeries for hilar, posterior location and presence of supernumerary vessels were found to be the a cause of difficulty. Trifecta outcomes were achieved in 37/49 patients (75.5%). The mean rating was 2.580±0.900 in trifecta negative patients while it was 1.410±0.832 in trifecta positive patient (p<0.0001). Surgeon's rating correlated positively with trifecta outcomes (likelihood ratio=15.75, p=0.006). Conclusions: The RNS remained a useful tool for determining renal tumor complexity. The intraoperative difficulty faced by the surgeon can be rated which can better predict perioperative trifecta outcomes. A useful predicting tool can be developed using the two parameters (RNS and surgeon rated difficulty).

Percutaneous Renal Biopsies for Small Renal Masses: Complex Tumors on Nephrometry Should Be the First Targets.

OBJECTIVE: To assess the diagnostic yield, accuracy, and complications rate for computed tomography (CT)-guided renal biopsies for solid renal masses (SRM); to analyze predictive factors for diagnostic biopsies. PATIENTS AND METHODS: We performed a single-center, retrospective study based on a pathologic database query for CT-guided, percutaneous renal biopsies. Inclusion criteria included presence of SRM; exclusion criteria included the presence of metastases, non-cT1a or higher cancer (> 4 cm), and non-CT-guided techniques. Of 119 patients who underwent renal biopsies, 40 (34%) were excluded from the study; 79 (66%) biopsy outcomes were analyzed. Clinical, radiologic (RENAL score), and pathologic features were reported. Differences between contributive and noncontributive biopsies were tested with Mann-Whitney U or chi-square tests, as appropriate. Multiple-variable analyses searching for predicting factors of biopsy contribution were performed with binary logistic regressions. RESULTS: CT-guided renal biopsies for SRM present a high yield (88.6%) and high accuracy for differentiating malignant from benign tumors (96%). They are less accurate for histologic subtype (93%) and unreliable for Fuhrman grading (64%). CT-guided renal biopsy is safe (minor complication rate, 2.5%) and helped prevent unnecessary surgery in 30.4% of the cohort. Tumor complexity with high RENAL score was a predictive factor (P = .02) of contributive biopsy. CONCLUSION: SRM biopsy is a safe, reliable procedure that can help determine the best treatment strategy for patients. It seems more beneficial for nephrometry complex tumors when surgical extirpation is more likely to be complicated. SRM biopsy might be encouraged in clinical practice for complex tumors.