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

OBJECTIVES: To obtain the most accurate assessment of the risks and benefits of selective clamping in robot-assisted partial nephrectomy (RAPN) we evaluated outcomes of this technique vs those of full clamping in patients with a solitary kidney undergoing RAPN. PATIENTS AND METHODS: Data from institutional review board-approved retrospective and prospective databases from 2006 to 2019 at multiple institutions with sharing agreements were evaluated. Patients with a solitary kidney were identified and stratified based on whether selective or full renal artery clamping was performed. Both groups were analysed with regard to demographics, risk factors, intra-operative complications, and postoperative outcomes using chi-squared tests, Fisher's exact tests, t-tests and Mann-Whitney U-tests. RESULTS: Our initial cohort consisted of 4112 patients, of whom 72 had undergone RAPN in a solitary kidney (51 with full clamping and 21 with selective clamping). There were no significant differences in demographics, tumour size, baseline estimated glomerular filtration rate (eGFR), or warm ischaemia time (WIT) between the groups (Table 1). Intra-operative outcomes, including estimated blood loss, operating time, and intra-operative complications were similar in the two groups. Short- and long-term postoperative percentage change in eGFR, frequency of acute kidney injury (AKI), and frequency of de novo chronic kidney disease (CKD) were also not significantly different between the two techniques. CONCLUSION: In a large cohort of patients with solitary kidney undergoing RAPN, selective clamping resulted in similar intra-operative and postoperative outcomes compared to full clamping and conferred no additional risk of harm. However, selective clamping did not appear to provide any functional advantage over full clamping as there was no difference observed in the frequency of AKI, CKD or change in eGFR. Short WIT in both groups (<15 min) may have prevented identification of benefits in the selective clamping group; a similar study analysing cases with longer WIT may elucidate any beneficial effects of selective clamping.

Do patients with Stage 3-5 chronic kidney disease benefit from ischaemia-sparing techniques during partial nephrectomy?

OBJECTIVE: To analyse whether selective arterial clamping (SAC) and off-clamp (OC) techniques during robot-assisted partial nephrectomy (RPN) are associated with a renal functional benefit in patients with Stage 3-5 chronic kidney disease (CKD). PATIENTS AND METHODS: The change in estimated glomerular filtration rate (eGFR) over time was compared between 462 patients with baseline CKD 3-5 that underwent RPN with main arterial clamping (MAC) (n = 375, 81.2%), SAC (n = 48, 10.4%) or OC (n = 39, 8.4%) using a multivariable linear mixed-effects model. All follow-up eGFRs, including baseline and follow-up between 3 and 24 months, were included in the model for analysis. The median follow-up was 12.0 months (interquartile range 6.7-16.5; range 3.0-24.0 months). RESULTS: In the multivariable linear mixed-effects model adjusting for characteristics including tumour size and the R.E.N.A.L. (Radius; Exophytic/Endophytic; Nearness; Anterior/Posterior; Location) Nephrometry Score, the change in eGFR over time was not significantly different between SAC and MAC RPN (ß = -1.20, 95% confidence interval [CI] -5.45, 3.06; P = 0.582) and OC and MAC RPN (ß = -1.57, 95% CI -5.21, 2.08; P = 0.400). Only 20 (15 MAC, two SAC, three OC) patients overall had progression of their CKD stage at last follow-up. The mean ischaemia time was 17 min for MAC and 15 min for SAC. There was no benefit to SAC or OC in terms of blood loss, perioperative complications, length of stay, or surgical margins. CONCLUSION: SAC and OC techniques during RPN were not associated with benefit in preservation of eGFR in patients with baseline CKD.

Urinary fistula after robot-assisted partial nephrectomy: a multicentre analysis of 1 791 patients.

OBJECTIVE: To evaluate the incidence of and risk factors for a urine leak in a large multicentre, prospective database of robot-assisted partial nephrectomy (RPN). PATIENTS AND METHODS: A database of 1 791 RPN from five USA centres was reviewed for urine leak as a complication of RPN. Patient and tumour characteristics were compared between patients with and those without postoperative urine leaks. Fisher's exact test was used for qualitative variables and Wilcoxon sum-rank tests were used for quantitative variables. A review of the literature on PN and urine leak was conducted. RESULTS: Urine leak was noted in 14/1 791 (0.78%) patients who underwent RPN. The mean (sd) nephrometry score of the entire cohort was 7.2 (1.9), and 8.0 (1.9) in patients who developed urine leak. The median (range) postoperative day of presentation was 13 (3-32) days. Patients with urine leak presented in delayed fashion with fever (two of the 14 patients, 14%), gastrointestinal complaints (four patients, 29%), and pain (five patients, 36%). Eight of the 14 patients (57%) required admission, while eight (57%) and nine (64%) had a drain or stent placed, respectively. Drains and stents were removed after a median (range) of 8 (4-13) days and 21 (8-83) days, respectively. Variables associated with urine leak included tumour size (P = 0.021), hilar location (P = 0.025), operative time (P = 0.006), warm ischaemia time (P = 0.005), and pelvicalyceal repair (P = 0.018). Upon literature review, the historical incidence of urine leak ranged from 1.0% to 17.4% for open PN and 1.6-16.5% for laparoscopic PN. CONCLUSION: The incidence of urine leak after RPN is very low and may be predicted by some preoperative factors, affording better patient counselling of risks. The low urinary leak rate may be attributed to the enhanced visualisation and suturing technique that accompanies the robotic approach.

Outcomes of robotic-assisted laparoscopic upper urinary tract reconstruction: 250 consecutive patients.

OBJECTIVE: To evaluate the long-term outcomes of robotic-assisted laparoscopic (RAL) upper urinary tract (UUT) reconstruction performed at a tertiary referral centre. MATERIALS AND METHODS: Data from 250 consecutive patients undergoing RAL UUT reconstruction, including pyeloplasty with or without stone extraction, ureterolysis, uretero-ureterostomy, ureterocalicostomy, ureteropyelostomy, ureteric reimplantation and buccal mucosa graft ureteroplasty, were collected at a tertiary referral centre between March 2003 and December 2013. The primary outcomes were symptomatic and radiographic improvement of obstruction and complication rate. The mean follow-up was 17.1 months. RESULTS: Radiographic and symptomatic success rates ranged from 85% to 100% for each procedure, with a 98% radiographic success rate and 97% symptomatic success rate for the entire series. There were a total of 34 complications, none greater than Clavien grade 3. CONCLUSION: Robotic-assisted laparoscopic UUT can be performed with few complications, with durable long-term success, and is a reasonable alternative to the open procedure in experienced robotic surgeons.

Near-infrared fluorescence imaging with intraoperative administration of indocyanine green for robotic partial nephrectomy.

Near-infrared fluorescence (NIRF) imaging with intraoperative administration of indocyanine green (ICG) is a technology with emerging applications in urologic surgery. ICG is a water-soluble dye that fluoresces bright green when viewed under near-infrared light (700-1000 nm). This technology has been applied to robotic partial nephrectomy, first to potentially allow for the differentiation of renal tumor from normal parenchyma. In this application, it has been hypothesized that normal kidney tissue fluoresces green, while the tumor commonly remains hypofluorescent, thereby aiding tumor excision. Secondly, NIRF imaging with ICG has been employed to facilitate selective arterial clamping during robotic partial nephrectomy, allowing for a regional perfusion deficit in the kidney to be readily identified and therefore targeted at a given tumor. Recent studies have shown the associated decrease in global ischemia to minimize resultant loss of renal function at certain time endpoints. This review presents the most recent studies and evidence on the intraoperative administration of indocyanine green for robotic partial nephrectomy.

Preoperative Predictors of Surgical Success for Robotic Ureteral Reconstruction of Proximal and Middle Ureteral Strictures.

OBJECTIVE: To investigate predictors of surgical success for patients undergoing robotic ureteral reconstruction (RUR) for ureteropelvic junction obstruction (UPJO), proximal, and middle ureteral stricture disease. METHODS: We retrospectively reviewed our multi-institutional Collaborative of Reconstructive Robotic Ureteral Surgery database to identify all consecutive patients undergoing RUR for UPJO, proximal and/or middle ureteral stricture disease between April 2012 and December 2020. The specific reconstruction technique was determined by the primary surgeon based on clinical history and intraoperative findings. Patients were grouped according to whether they were surgical successful. Preoperative variables between both groups were compared using chi-square tests. All independent variables with associations of P <.2 then underwent a binary logistic regression analysis to determine predictive variables of success for RUR (P ≤.05 was considered statistically significant). RESULTS: Overall, 338 patients met inclusion criteria. Surgical success rates of RUR are shown in Table 1. Univariate analysis (Table 2) showed that there were a lower proportion of patients with diabetes (8.9% vs 25.7%, P <.01) and a higher proportion of patients who underwent ureteral rest (74.3% vs 48.6%, P <.01) in the surgical success group. Multivariate logistic regression analysis (Table 3) further revealed the odds of surgical success in patients without diabetes was 3.08 times ((confidence interval) CI 1.26-7.54, P = .01) the odds of success for patients with diabetes. The odds of surgical success in patients who underwent preoperative ureteral rest were 2.8 times (CI 1.35-5.83, P = .01) the odds of success for patients who did not undergo preoperative ureteral rest. CONCLUSION: Surgical success of RUR for management of UPJO, proximal, and middle ureteral strictures may be influenced by factors including preoperative ureteral rest and presence of diabetes.

Comparison of lateral flank approach and low anterior access for single port (SP) retroperitoneal partial nephrectomy: an analysis from the single port advanced research consortium (SPARC).

Single Port (SP) robotic partial nephrectomy (RPN) can be performed via retroperitoneal and transperitoneal approach. We aim to compare outcomes of two commonly described incisions for retroperitoneal SP RPN: lateral flank approach (LFA) and low anterior access (LAA). We performed a retrospective study of patients who underwent SP retroperitoneal RPN from 2018 to 2023 as part of a large multi-institute collaboration (SPARC). Baseline demographic, clinical, tumor-specific characteristics, and perioperative outcomes were compared using χ2, t test, Fisher exact test, and Mann-Whitney U test. Multivariable analyses were conducted using robust and logistic regressions. A total of 70 patients underwent SP retroperitoneal RPN, with 44 undergoing LAA. Overall, there were no significant differences in baseline characteristics between the two groups. The LAA group exhibited significantly lower median RENAL scores (8 vs. 5, p < 0.001) and more varied tumor locations (p = 0.002). In the bivariate analysis, there were no statistically significant differences in ischemia time, estimated blood loss, or complication rates between the groups. However, the LAA group had longer operative times (101 vs. 134 min, p < 0.001), but was more likely to undergo a same-day discharge (p < 0.001). When controlling for other variables, LAA was associated with shorter ischemia time (p = 0.005), but there was no significant difference in operative time (p = 0.348) and length of stay (p = 0.122). Both LFA and LAA are acceptable approaches for SP retroperitoneal RPN with comparable perioperative outcomes. This early data suggests the LAA is more versatile for varying tumor locations; however, larger cohort studies are needed to ascertain whether there is an overall difference in patient recovery.

Outcomes and predictors of clinical T1 to pathological T3a tumor up-staging after robotic partial nephrectomy: a multi-institutional analysis.

PURPOSE: We evaluated the early oncological end point of recurrence-free survival in patients with renal cell carcinoma up-staged from cT1 to pT3a after partial nephrectomy. We also aimed to establish preoperative factors associated with pathological tumor up-staging. MATERIALS AND METHODS: A prospective database of robotic partial nephrectomy cases performed at 5 academic centers was queried for patients who underwent surgery for a solitary cT1 renal mass. Patients with pT1-2 renal cell carcinoma were compared to those with pT3a tumors to determine the difference in recurrence-free survival. Preoperative factors associated with cT1 to pT3a up-staging were studied using multivariate logistic regression analysis. RESULTS: A total of 1,096 patients underwent robotic partial nephrectomy for a cT1 renal mass. At final pathological evaluation 855 tumors (78.0%) were found to be renal cell carcinoma, of which 41 (4.8%) were up-staged to pT3a. The 24-month recurrence-free survival estimates for pT1-2 and pT3a tumors were 99.2% and 91.8%, respectively (p=0.003). Multivariate analysis revealed that a high vs low R.E.N.A.L. (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior and location relative to polar lines) nephrometry score was associated with tumor up-staging (OR 2.97, 95% CI 1.20-7.35, p=0.02). On separate multivariate analysis increasing tumor diameter (OR 1.66, 95% CI 1.32-2.08, p<0.001) and hilar location (OR 2.83, 95% CI 1.43-5.61, p=0.003) were also associated with up-staging. CONCLUSIONS: At short-term followup patients with renal cell carcinoma up-staged from cT1 to pT3a have reasonable oncological outcomes after partial nephrectomy. Factors associated with tumor up-staging include high tumor complexity, increasing tumor diameter and hilar location. Further studies are needed to determine the comparative efficacy of partial vs radical nephrectomy for small pT3a tumors.

Near-infrared fluorescence imaging to facilitate super-selective arterial clamping during zero-ischaemia robotic partial nephrectomy.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: There is concern that warm ischaemia time during partial nephrectomy may have an adverse impact on postoperative renal function. As a result, there is increased interest in developing a safe and effective method for performing non-ischaemic partial nephrectomy. Several novel approaches have recently been described. We present our initial experience performing zero-ischaemia partial nephrectomy using near-infrared fluorescence imaging to facilitate super-selective arterial clamping. We report the operative and early postoperative outcomes from such cases as compared with a matched cohort of patients undergoing traditional partial nephrectomy with clamping of the main renal artery. We show that this technique is both safe and effective and may lead to improved renal preservation at short-term follow-up. OBJECTIVE: To describe a novel technique of eliminating renal ischaemia during robotic partial nephrectomy (RPN) using near-infrared fluorescence (NIRF) imaging. PATIENTS AND METHODS: Over an 8-month period (March 2011 to November 2011), 34 patients were considered for zero-ischaemia RPN using the da Vinci NIRF system. Targeted tertiary/higher-order tumour-specific branches were controlled with robotic bulldog(s) or neurosurgical aneurysm micro-bulldog(s). Indocyanine green dye was given, and NIRF imaging used to confirm super-selective ischaemia, defined as darkened tumour/peri-tumour area with green fluorescence of remaining kidney. Matched pair analysis was performed by matching each patient undergoing zero-ischaemia RPN (n = 27) to a previous conventional RPN (n = 27) performed by the same surgeon. RESULTS: Of 34 patients, 27 (79.4%) underwent successful zero-ischaemia RPN; seven (20.6%) required conversion to main renal artery clamping (ischaemia time <30 min) for the following reasons: persistent tumour fluorescence after clamping indicating inadequate tumoral devascularization (n = 5), and parenchymal bleeding during RPN (n = 2). Matched-pair analysis showed comparable outcomes between cohorts, except for longer operating time (256 vs 212 min, P = 0.02) and superior kidney function (reduction of estimated glomerular filtration rate (-1.8% vs -14.9%, P = 0.03) in the zero-ischaemia cohort. All surgical margins were negative. CONCLUSIONS: In this pilot study, we show that zero-ischaemia RPN with NIRF is a safe alternative to conventional RPN with main renal artery clamping. Eliminating global ischaemia may improve functional outcomes at short-term follow-up.

Immediate gemcitabine bladder instillation following bladder closure during robotic-assisted radical nephroureterectomy: a multi-institutional report of feasibility and initial outcomes.

Background: Bladder recurrence after radical nephroureterectomy (RNU) is common and randomized data supports utilization of prophylactic intravesical mitomycin to reduce recurrence. Recently, gemcitabine has been shown to be safe and effective at reducing recurrence following transurethral resection of bladder tumors. We sought to evaluate the safety and efficacy of a single, intraoperative gemcitabine instillation immediately following bladder cuff closure during RNU, and to compare outcomes with non-gemcitabine intravesical chemotherapy agents. Methods: We retrospectively reviewed all patients from two high volume centers who underwent robotic-assisted RNU between 2016-2020 and received either 2 g intravesical gemcitabine immediately following bladder cuff closure or non-gemcitabine intravesical chemotherapies [40 mg mitomycin C (MMC) or 50 mg doxorubicin] at the beginning of the procedure. Clinicopathologic factors were compared between cohorts. Bladder recurrence rates were evaluated using the Kaplan-Meier method and log-rank test. Results: During RNU, 24 patients received gemcitabine and 31 patients received non-gemcitabine chemotherapy. In total, 35% (19/55) of patients experienced a bladder cancer recurrence. There was no significant difference in estimated bladder recurrence-free survival (bRFS) between gemcitabine and non-gemcitabine patient cohorts (P=0.64). By 12 months post-surgery, 25% of patients had experienced bladder recurrence. The estimated 1-year bladder RFS survival was 73% for gemcitabine and 76% for non-gemcitabine chemotherapy. Overall survival and cancer-specific survival did not differ between cohorts. No adverse events potentially attributable to the use of gemcitabine were noted within 30 days postoperatively. Conclusions: Gemcitabine instilled immediately following bladder cuff closure during RNU has similar bRFS rates compared to established chemotherapy agents instilled at the start of surgery.

Robotic ureteral reconstruction for recurrent strictures after prior failed management.

Objectives: To describe our multi-institutional experience with robotic ureteral reconstruction (RUR) in patients who failed prior endoscopic and/or surgical management. Materials and Methods: We retrospectively reviewed our Collaborative of Reconstructive Robotic Ureteral Surgery (CORRUS) database for all consecutive patients who underwent RUR between 05/2012 and 01/2020 for a recurrent ureteral stricture after having undergone prior failed endoscopic and/or surgical repair. Post-operatively, patients were assessed for surgical success, defined as the absence of flank pain and obstruction on imaging. Results: Overall, 105 patients met inclusion criteria. Median stricture length was 2 (IQR 1-3) centimetres. Strictures were located at the ureteropelvic junction (UPJ) (41.0%), proximal (14.3%), middle (9.5%) or distal (35.2%) ureter. There were nine (8.6%) radiation-induced strictures. Prior failed management included endoscopic intervention (49.5%), surgical repair (25.7%) or both (24.8%). For repair of UPJ and proximal strictures, ureteroureterostomy (3.4%), ureterocalicostomy (5.2%), pyeloplasty (53.5%) or buccal mucosa graft ureteroplasty (37.9%) was utilized; for repair of middle strictures, ureteroureterostomy (20.0%) or buccal mucosa graft ureteroplasty (80.0%) was utilized; for repair of distal strictures, ureteroureterostomy (8.1%), side-to-side reimplant (18.9%), end-to-end reimplant (70.3%) or appendiceal bypass (2.7%) was utilized. Major (Clavien >2) post-operative complications occurred in two (1.9%) patients. At a median follow-up of 15.1 (IQR 5.0-30.4) months, 94 (89.5%) cases were surgically successful. Conclusions: RUR may be performed with good intermediate-term outcomes for patients with recurrent strictures after prior failed endoscopic and/or surgical management.

The State of Robotic Partial Nephrectomy: Operative, Functional, and Oncological Outcomes From A Robust Multi-Institution Collaborative.

OBJECTIVE: To describe the most recent surgical, functional, and oncological outcomes of RPN utilizing one of the largest, prospectively maintained, multi-institution consortium of patients undergoing robotic renal surgery. MATERIALS AND METHODS: Data was obtained from a prospectively maintained multi-institutional database of patients who underwent RPN for clinically localized kidney cancer between 2018 and 2022 by 9 high-volume surgeons. Demographic and tumor characteristics as well as operative, functional, and oncological outcomes were queried. RESULTS: A total of 2836 patients underwent RPN. Intraoperative, postoperative, and 30-day major complication rates were 2.68%, 11.39%, and 3.24%, respectively. Median tumor size was 3.0 cm. Tumors with low complexity had a shorter median operative time, lower median EBL, shorter median ischemia time, lower postoperative complication rate, and lower decline in renal function There was no significant difference between tumor complexities with respect to the rate of conversion to radical nephrectomy, conversion to open, major complications, and positive margins. Lower BMI, smaller clinical tumor size, lower tumor complexity, and higher baseline eGFR were significantly associated with trifecta achievement. CONCLUSION: Patient BMI, baseline eGFR, and tumor characteristics such as size and complexity are the most important predictors of trifecta achievement. Patients with complex tumors should be counseled that they are at increased risk of complications and worsening renal function after robotic partial nephrectomy.

A Multi-Institutional Experience Utilizing Boari Flap in Robotic Urinary Reconstruction.

Objectives: There is presently scarce literature describing the outcomes of patients undergoing robotic ureteral reconstruction (RUR) using the Boari flap (BF) technique. Herein, we report our prospective, multi-institutional experience using BF in patients undergoing robotic urinary reconstruction. Patients and Methods: We reviewed our prospective, multicenter database for all patients undergoing RUR between September 2013 and September 2021 in which a BF was utilized. Preoperative, perioperative, and follow-up data were collected and analyzed. Major complications were defined as a Clavien-Dindo classification grade >2. Surgical failure was defined as recurrent symptoms, obstruction on imaging, or the need for additional surgical interventions. Results: We identified 50 patients who underwent RUR using a BF. Four (8%) underwent the Single Port approach. Twenty-four patients (48%) were active or former tobacco users. Thirty-four patients (68%) had previously undergone abdominal surgery, 17 (34%) had prior ureteral stricture interventions, and 9 (18%) had prior abdominopelvic radiation. The most common stricture etiology was malignancy (34.4%). The median follow-up was 15.0 months with a 90% (45/50) success rate. The five documented cases of failure occurred at a median of 1.8 months following the procedure. Conclusion: In the largest prospective, multi-institutional study of patients undergoing RUR with BF in the literature to date, we demonstrate a low rate of complications and a high rate of surgical success in three tertiary academic medical centers. All observed failures occurred within 2 months of surgical intervention.

Transperitoneal Versus Retroperitoneal Single-port Robotic-assisted Partial Nephrectomy: An Analysis from the Single Port Advanced Research Consortium.

BACKGROUND: In the surgical management of kidney tumors, such as in multiport technology, single-port (SP) robotic-assisted partial nephrectomy (RAPN) can be performed using the transperitoneal (TP) or retroperitoneal (RP) approach. However, there is a dearth of literature on the efficacy and safety of either approach for SP RAPN. OBJECTIVE: To compare the peri- and postoperative outcomes of the TP and RP approaches for SP RAPN. DESIGN, SETTING, AND PARTICIPANTS: This is a retrospective cohort study using data from the Single Port Advanced Research Consortium (SPARC) database of five institutions. All patients underwent SP RAPN for a renal mass between 2019 and 2022. INTERVENTION: TP versus RP SP RAPN. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Baseline characteristics, and peri- and postoperative outcomes were compared between both the approaches using χ2 test, Fisher exact test, Mann-Whitney U test, and Student t test. RESULTS AND LIMITATIONS: A total of 219 patients (121 [55.25%] TP, 98 [44.75%] RP) were included in the study. Of them, 115 (51.51%) were male, and the mean age was 60 ± 11 yr. RP had a significantly higher proportion of posterior tumors (54 [55.10%] RP vs 28 [23.14%] TP, p < 0.001), while other baseline characteristics were comparable between both the approaches. There was no statistically significant difference in ischemia time (18 ± 9 vs 18 ± 11 min, p = 0.898), operative time (147 ± 67 vs 146 ± 70 min, p = 0.925), estimated blood loss (p = 0.167), length of stay (1.06 ± 2.25 vs 1.33 ± 1.05 d, p = 0.270), overall complications (5 [5.10%] vs 7 [5.79%]), and major complication rate (2 [2.04%] vs 2 [1.65%], p = 1.000). No difference was observed in positive surgical margin rate (p = 0.472) or delta eGFR at median 6-mo follow-up (p = 0.273). Limitations include retrospective design and no long-term follow-up. CONCLUSIONS: With proper patient selection based on patient and tumor characteristics, surgeons can opt for either the TP or the RP approach for SP RAPN, and maintain satisfactory outcomes. PATIENT SUMMARY: The use of a single port (SP) is a novel technology for performing robotic surgery. Robotic-assisted partial nephrectomy (RAPN) is a surgery to remove a portion of the kidney due to kidney cancer. Depending on patient characteristics and surgeons' preference, SP can be performed via two approaches for RAPN: through the abdomen or through the space behind the abdominal cavity. We compared outcomes between these two approaches for patients receiving SP RAPN, finding that they were comparable. We conclude that with proper patient selection based on patient and tumor characteristics, surgeons can opt for either the TP or the RP approach for SP RAPN, and maintain satisfactory outcomes.

A comparison of outcomes between transperitoneal and retroperitoneal robotic assisted partial nephrectomy in patients with completely endophytic kidney tumors.

INTRODUCTION: Retroperitoneal robotic partial nephrectomy (RPN) has been shown to have comparable outcomes to the transperitoneal approach for renal tumors. However, this may not be true for completely endophytic tumors as they pose significant challenges in RPN with increased complication rates. Hence, we sought to compare the safety and feasibility of retroperitoneal RPN to transperitoneal RPN for completely endophytic tumors. METHODS: We performed a retrospective analysis of patients who underwent RPN for a completely endophytic renal mass using either transperitoneal or retroperitoneal approach from our multi-institutional database (n = 177). Patients who had a solitary kidney, prior ipsilateral surgery, multiple/bilateral tumors, and horseshoe kidneys were excluded from the analysis. Overall, 156 patients were evaluated (112 [71.8%] transperitoneal, 44 [28.2%] retroperitoneal). Baseline characteristics, perioperative and postoperative data were compared between the surgical transperitoneal and retroperitoneal approach using Chi-square test, Fishers exact test, t test, Mood median test and Mann Whitney U test. RESULTS: Of the 156 patients in this study, 86 (56.9%) were male and the mean (SD) age was 58 (13) years. Baseline characteristics were comparable between the 2 approaches. Compared to transperitoneal approach, retroperitoneal approach had similar ischemia time (19.6 [SD = 7.6] minutes vs. 19.5 [SD = 10.2] minutes, P = 0.952), operative time (157.5 [SD = 44.8] minutes vs. 160.2 [SD = 47.3] minutes, P = 0.746), median estimated blood loss (50 ml [IQR: 50, 150] vs. 100 ml [IQR: 50, 200], P = 0.313), median length of stay (1 [IQR: 1, 2] day vs. 1 [IQR: 1, 2] day, P = 0.126) and major complication rate (2 [4.6%] vs. 3 [2.7%], P = 0.621). No difference was observed in positive surgical margin rate (P = 0.1.00), delta eGFR (P = 0.797) and de novo chronic kidney disease occurrence (P = 1.000). CONCLUSION: Retroperitoneal and transperitoneal RPN yielded similar perioperative and functional outcomes in patients with completely endophytic tumors. In well-selected patients with purely endophytic tumors, either a retroperitoneal or transperitoneal approach could be considered without compromising perioperative and postoperative outcomes.

Transperitoneal Versus Retroperitoneal Robotic-Assisted Partial Nephrectomy in Patients with Obesity.

Introduction: We aim to compare transperitoneal (TP) and retroperitoneal (RP) robotic partial nephrectomy (RPN) in obese patients. Obesity and RP fat can complicate RPN, especially in the RP approach where working space is limited. Materials and Methods: Using a multi-institutional database, we analyzed 468 obese patients undergoing RPN for a renal mass (86 [18.38%] RP, 382 [81.62%] TP). Obesity was defined as body mass index ≥30 kg/m2*. A 1:1 propensity score matching was performed adjusting for age, previous abdominal surgery, tumor size, R.E.N.A.L nephrometry score, tumor location, surgical date, and participating centers. Baseline characteristics and perioperative and postoperative data were compared. Results: In the propensity score-matched cohort, 79 (50%) TP patients were matched with 79 (50%) RP patients. The RP group had more posterior tumors (67 [84.81%], RP versus 23 [29.11%], TP; P < .001), while the other baseline characteristics were comparable. Warm ischemia time (interquartile range; 15 [10, 12], RP versus 14 [10, 17] minutes, TP; P = .216), operative time (129 [116, 165], RP versus 130 [95, 180] minutes, TP; P = .687), estimated blood loss (50 [50, 100], RP versus 75 [50, 150] mL, TP; P = .129), length of stay (1 [1, 1], RP versus 1 [1, 2] day, TP; P = .319), and major complication rate (1 [1.27%], RP versus 3 [3.80%], TP; P = .620) were similar. No significant difference was observed in positive surgical margin rate and delta estimated glomerular filtration at follow-up. Conclusion: TP and RP RPN yielded similar perioperative and postoperative outcomes in obese patients. Obesity should not be a factor in determining optimal approach for RPN.

Robot-assisted partial nephrectomy for complex renal tumors: Analysis of a large multi-institutional database.

INTRODUCTION: Highly complex renal masses pose a challenge to urologic surgeons' ability to perform robotic partial nephrectomy (RPN). Given the increased utilization of the robotic approach for small renal masses, we sought to characterize the outcomes and determine the safety and feasibility of RPN for complex renal masses from our large multi-institutional cohort. METHODS: We performed a retrospective analysis of patients with R.E.N.A.L. Nephrometry Scores ≥10 who underwent RPN in our multi-institutional cohort (N = 372). Baseline demographic, clinical and tumor related characteristics were evaluated with the primary endpoint of trifecta achievement (defined as negative surgical margin, no major complications, and warm ischemia time ≤25 min). Relationships between variables were assessed using the chi-square test of independence, Fisher exact test, Mann-Whitney U test, and Kruskal Wallis test. Logistic regression was used to evaluate the relationship between baseline characteristics and trifecta achievement. RESULTS: Of 372 patients in the study, mean age was 58 years, and median BMI was 30.49 kg/m2. The median tumor size was 4.3 cm (3.0-5.9 cm). Most of the patients had R.E.N.A.L. scores of 10 (n = 253; 67.01%). Overall, trifecta was achieved in 72.04% of patients. Stratifying intraoperative and postoperative outcomes by R.E.N.A.L. scores, there was no significant difference in trifecta achievement, operative time, warm ischemia time (WIT), open conversion, major complication, or positive margin rates. Length of hospital stay was significantly longer for higher R.E.N.A.L. scores (median days 2 vs. 1, P = 0.012). Multivariate analyses for factors associated with trifecta achievement concluded that age and baseline eGFR were independently associated with trifecta achievement. CONCLUSION: RPN is a safe and reproducible procedure for complex tumors with R.E.N.A.L. Nephrometry scores ≥10. Our results suggest excellent rates of trifecta achievement and short-term functional outcomes when performed by experienced surgeons. Long-term oncological and functional evaluation are needed to further support this conclusion.

Operative and oncological outcomes of salvage robotic radical and partial nephrectomy: a multicenter experience.

We aim to describe the perioperative and oncological outcomes for salvage robotic partial nephrectomy (sRPN) and salvage robotic radical nephrectomy (sRRN). Using a prospectively maintained multi-institutional database, we compared baseline clinical characteristics and perioperative and postoperative outcomes, including pathological stage, tumor histology, operative time, ischemia time, estimated blood loss (EBL), length of stay (LOS), postoperative complication rate, recurrence rate, and mortality. We identified a total of 58 patients who had undergone robotic salvage surgery for a recurrent renal mass, of which 22 (38%) had sRRN and 36 (62%) had sRPN. Ischemia time for sRPN was 14 min. The median EBL was 100 mL in both groups (p = 0.581). One intraoperative complication occurred during sRRN, while three occurred during sRPN cases (p = 1.000). The median LOS was 2 days for sRRN and 1 day for sRPN (p = 0.039). Postoperatively, one major complication occurred after sRRN and two after sRPN (p = 1.000). The recurrence reported after sRRN was 5% and 3% after sRPN. Among the patients who underwent sRRN, the two most prevalent stages were pT1a (27%) and pT3a (27%). Similarly, the two most prevalent stages in sRPN patients were pT1a (69%) and pT3a (6%). sRRN and sRPN have similar operative and perioperative outcomes. sRPN is a safe and feasible procedure when performed by experienced surgeons. Future studies on large cohorts are essential to better characterize the importance and benefit of salvage partial nephrectomies.

Tumor complexity predicts malignant disease for small renal masses.

PURPOSE: Approximately 20% to 30% of suspicious small renal tumors are benign. A significant proportion of malignant tumors are low grade and potentially indolent. We evaluated whether preoperative patient and tumor characteristics are associated with adverse pathological features. MATERIALS AND METHODS: A total of 886 patients underwent robot-assisted partial nephrectomy, as done by 1 of 5 high volume surgeons. Demographic and clinical data were compared between patients with benign/malignant disease, clear cell/nonclear cell renal cell carcinoma and high/low grade tumors. Tumor complexity was quantified by R.E.N.A.L. (radius, exophytic/endophytic, nearness of tumor to collecting system or sinus, anterior/posterior, hilar and location relative to polar lines) nephrometry score and described as low--4 to 6, intermediate--7 to 9 or high--10 or greater. Logistic regression analyses were performed to test the association between tumor and patient characteristics, and high grade renal cell carcinoma. Subanalyses were done for patients with renal tumors 4 cm or less. RESULTS: High grade renal cell carcinoma was larger and more likely to develop in men. Patients with malignant tumors and with clear cell histology were more likely to have intermediate or high complexity tumors. Increasing tumor complexity independently predicted malignancy, high grade malignancy and clear cell histology on multivariate regression analysis (each p <0.05). Male gender was independently associated with malignancy and high grade renal cell carcinoma. When considering tumors 4 cm or less, tumor complexity predicted malignancy but not tumor grade. CONCLUSIONS: High R.E.N.A.L nephrometry score and male gender are associated with an increased risk of malignancy and high grade malignancy in tumors treated with partial nephrectomy.

Utility of MRI features for differentiation of retroperitoneal fibrosis and lymphoma.

OBJECTIVE: The objective of our study was to retrospectively compare the MRI features of retroperitoneal fibrosis (RPF) and lymphoma presenting as confluent retroperitoneal soft tissue. MATERIALS AND METHODS: MRI studies of 31 patients (18 men, 13 women; mean age, 58.4 ± 15.8 [SD] years; 22 with RPF and nine with lymphoma) were evaluated. Two radiologists independently and in consensus evaluated all cases for an array of subjective imaging features. A third radiologist measured the size (i.e., the greatest dimension in the transverse plane) and apparent diffusion coefficient (ADC) value of the tissue. Features of RPF and lymphoma were compared using the Fisher exact test, Mann-Whitney test, and receiver operating characteristic (ROC) curve analysis. Interreader concordance was also calculated. RESULTS: The mean age of patients with lymphoma was significantly greater than that in cases of RPF (72.4 ± 13.3 [SD] vs 52.7 ± 13.2 years, respectively; p = 0.003). The MRI features significantly more common in patients with RPF were pelvic extension (p = 0.004) and medial ureteral bowing (p < 0.001). The MRI features significantly more common in cases of lymphoma were predominantly suprarenal location, perirenal extension, anterior aortic displacement, heterogeneity, and the presence of additional nodes (p < 0.001-0.043). Size was significantly greater in patients with lymphoma than in those with RPF (mean ± SD, 33.9 ± 17.3 vs 11.0 ± 5.7 mm; p < 0.001) and had an area under the curve (AUC) of 0.960; a size larger than 15 mm had sensitivity of 100% and specificity of 86.4% for the diagnosis of lymphoma. The ADC was significantly lower in lymphoma than in RPF (mean ± SD, 0.92 ± 0.17 vs 1.40 ± 0.38 × 10(-3) mm(2)/s; p = 0.003) and had an AUC of 0.904. An ADC of 0.955 × 10(-3) mm(2)/s or less had sensitivity of 83.3% and specificity of 89.5% for the diagnosis of lymphoma. Interreader concordance for subjective features was very good to excellent (range, 80.6-100%). CONCLUSION: MRI features may be helpful in distinguishing between RPF and lymphoma.