Preoperative proteinuria is associated with increased rates of acute kidney injury after partial nephrectomy

ABSTRACT Purpose We investigated the association between preoperative proteinuria and early postoperative renal function after robotic partial nephrectomy (RPN). Patients and Methods We retrospectively reviewed 1121 consecutive RPN cases at a single academic center from 2006 to 2016. Patients without pre-existing CKD (eGFR≥60 mL/min/1.73m2) who had a urinalysis within 1-month prior to RPN were included. The cohort was categorized by the presence or absence of preoperative proteinuria (trace or greater (≥1+) urine dipstick), and groups were compared in terms of clinical and functional outcomes. The incidence of acute kidney injury (AKI) was assessed using RIFLE criteria. Univariate and multivariable models were used to identify factors associated with postoperative AKI. Results Of 947 patients, 97 (10.5%) had preoperative proteinuria. Characteristics associated with preoperative proteinuria included non-white race (p<0.01), preoperative diabetes (p<0.01) and hypertension (HTN) (p<0.01), higher ASA (p<0.01), higher BMI (p<0.01), and higher Charlson score (p<0.01). The incidence of AKI was higher in patients with preoperative proteinuria (10.3% vs. 4.6%, p=0.01). The median eGFR preservation measured within one month after surgery was lower (83.6% vs. 91%, p=0.04) in those with proteinuria; however, there were no significant differences by 3 months after surgery or last follow-up visit. Independent predictors of AKI were high BMI (p<0.01), longer ischemia time (p<0.01), and preoperative proteinuria (p=0.04). Conclusion Preoperative proteinuria by urine dipstick is an independent predictor of postoperative AKI after RPN. This test may be used to identify patients, especially those without overt CKD, who are at increased risk for developing AKI after RPN.

Preoperative proteinuria is associated with increased rates of acute kidney injury after partial nephrectomy.

PURPOSE: We investigated the association between preoperative proteinuria and early postoperative renal function after robotic partial nephrectomy (RPN). PATIENTS AND METHODS: We retrospectively reviewed 1121 consecutive RPN cases at a single academic center from 2006 to 2016. Patients without pre-existing CKD (eGFR≥60 mL/min/1.73m2) who had a urinalysis within 1-month prior to RPN were included. The cohort was categorized by the presence or absence of preoperative proteinuria (trace or greater (≥1+) urine dipstick), and groups were compared in terms of clinical and functional outcomes. The incidence of acute kidney injury (AKI) was assessed using RIFLE criteria. Univariate and multivariable models were used to identify factors associated with postoperative AKI. RESULTS: Of 947 patients, 97 (10.5%) had preoperative proteinuria. Characteristics associated with preoperative proteinuria included non-white race (p<0.01), preoperative diabetes (p<0.01) and hypertension (HTN) (p<0.01), higher ASA (p<0.01), higher BMI (p<0.01), and higher Charlson score (p<0.01). The incidence of AKI was higher in patients with preoperative proteinuria (10.3% vs. 4.6%, p=0.01). The median eGFR preservation measured within one month after surgery was lower (83.6% vs. 91%, p=0.04) in those with proteinuria; however, there were no significant differences by 3 months after surgery or last follow-up visit. Independent predictors of AKI were high BMI (p<0.01), longer ischemia time (p<0.01), and preoperative proteinuria (p=0.04). CONCLUSION: Preoperative proteinuria by urine dipstick is an independent predictor of postoperative AKI after RPN. This test may be used to identify patients, especially those without overt CKD, who are at increased risk for developing AKI after RPN.

Development and Internal Validation of a Nomogram for Predicting Renal Function after Partial Nephrectomy.

Loss of renal function can be a clinically impactful event after partial nephrectomy (PN). We aimed to create a model to predict loss of renal function in patients undergoing PN. Data for 1897 consecutive patients who underwent PN with warm ischemia between 2008 and 2017 were extracted from our institutional database. Loss of renal function was defined as upstaging of chronic kidney disease in terms of the estimated glomerular filtration rate (eGFR) at 3 mo after PN. A nomogram was built based on a multivariable model comprising age, sex, body mass index, baseline eGFR, RENAL score, and ischemia time. Interval validation and calibration were performed using data from 676 patients for whom complete data were available. Receiver operator characteristic (ROC) curves with 1000 bootstrap replications were plotted, as well as the observed incidence versus the nomogram-predicted probability. We also applied the extreme training versus test procedure known as leave-one-out cross-validation. After internal validation, the area under the ROC curve was 76%. The model demonstrated excellent calibration. At an upstaging cutoff of 27% probability, upstaging was predicted with a positive predictive value of 86%. PATIENT SUMMARY: In this report, we created a model to predict postoperative loss of renal function after partial nephrectomy for renal tumors. Inputting baseline characteristics and ischemia time into our model allows early identification of patients at higher risk of renal function decline after partial nephrectomy with good predictive power.

Transperitoneal Robot-assisted Partial Nephrectomy with Minimum Follow-up of 5 Years: Oncological and Functional Outcomes from a Single Institution.

BACKGROUND: Robot-assisted partial nephrectomy (RAPN) is an established, minimally invasive nephron-sparing technique with excellent perioperative and intermediate oncological outcomes. However, long-term oncological outcomes have not been reported to date. OBJECTIVE: To report oncological and functional outcomes of RAPN among patients with minimum follow-up of 5 yr. DESIGN, SETTING, AND PARTICIPANTS: Data for consecutive patients undergoing RAPN since October 2006 were extracted from a prospectively-maintained institutional PN database. Patients with benign tumors, genetic mutations, prior radical or ipsilateral PN, and those with follow-up of <5 yr were excluded. INTERVENTION: Transperitoneal RAPN for renal cell carcinoma (RCC). OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS: Demographic, perioperative, postoperative, functional, and oncological data were evaluated. A linear random-effects model was used to estimate the effect of follow-up duration on the estimated glomerular filtration rate (eGFR) after adjustment for potential confounders. Univariable competing-risks regression analyses were performed to evaluate the hazard ratio (HR) for cancer-related events for the variables of interest. RESULTS AND LIMITATIONS: A total of 278 RAPNs for RCC were included. eGFR was significantly lower at follow-up time points than at baseline. At last follow-up (median 46 mo, interquartile range 30-58) the mean eGFR difference was -10.6ml/min (95% confidence interval -12.56 to -8.66; p < 0.0001). There were 28 deaths (10.1%) in the cohort during the follow-up period, of which five (1.8%) were related to metastatic RCC. The 5-yr and 7-yr cumulative incidence of RCC deaths was 1.80% at both 5 and 7 yr, while the cumulative incidence of local recurrence was 3.61% and 4.16%, and that of metastasis was 3.24% and 4.57% at 5 and 7 yr, respectively. Univariable competing-risks regression revealed that higher Fuhrman grade (HR 8.76; p = 0.051), larger tumor size (HR 1.67; p < 0.0001), and tumor necrosis (HR 16.73; p = 0.0019) were independent predictors of RCC death. The retrospective design and potential selection bias due to patient selection in the early RAPN experience may limit the generalizability of the findings. CONCLUSIONS: This is the first study reporting minimum oncological follow-up of 5 yr after RAPN. The results demonstrate excellent long-term oncological outcomes after RAPN in a selected cohort of patients. Our data confirm that the renal functional deterioration after RAPN remains stable over time after the early postoperative decrease. PATIENT SUMMARY: Robot-assisted partial nephrectomy is being more widely used as a standard treatment for small localized renal cell carcinomas. This study reveals excellent long-term cancer control for both local recurrences and distant metastases. Renal function is stable after an initial postoperative deterioration.

Robotic partial nephrectomy after pazopanib treatment in a solitary kidney with segmental vein thrombosis.

OBJECTIVE: To demonstrate our surgical technique of robotic partial nephrectomy (RPN) in a patient with a solitary kidney who received neoadjuvant Pazopanib, highlighting the multidisciplinary approach. MATERIALS AND METHODS: In our video, we present the case of 77-year-old male, Caucasian with 6.6cm left renal neoplasm in a solitary kidney. An initial percutaneous biopsy from the mass revealed clear cell RCC ISUP 2. After multidisciplinary tumor board meeting, Pazopanib (800mg once daily) was administered for 8 weeks with repeat imaging at completion of therapy. Post-TKI image study was compared with the pre-TKI CT using the Morphology, Attenuation, Size, and Structure criteria showing a favorable response to the treatment. Thereafter, a RPN was planned3. Perioperative surgical outcomes are presented. RESULTS: Operative time was 224 minutes with a cold ischemia time of 53 minutes. Estimated blood loss was 800ml and the length of hospital stay was 4 days. Pathology demonstrated a specimen of 7.6cm with a tumor size of 6.5cm consistent with clear cell renal carcinoma ISUP 3 with a TNM staging pT1b Nx. Postoperative GFR was maintained at 24 ml / min compared to the preoperative value of 33ml / min. CONCLUSIONS: A multidisciplinary approach is effective for patients in whom nephron preservation is critical, providing na opportunity to select those that may benefi t from TKI therapy. Pazopanib may allow for PN in a highly selective subgroup of patients who would otherwise require radical nephrectomy. Prospective data will be necessary before this strategy can be disseminated into clinical practice. Available at: http://www.intbrazjurol.com.br/video-section/20180240_Garisto_et_al.

"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.

Predictors of positive surgical margins in patients undergoing partial nephrectomy: A large single-center experience.

OBJECTIVE: To identify preoperative factors that predict positive surgical margins in partial nephrectomy. MATERIAL AND METHODS: Using our institutional partial nephrectomy database, we investigated the patients who underwent partial nephrectomy for malignant tumors between January 2011 and December 2015. Patient, tumor, surgeon characteristics were compared by surgical margin status. Multivariable logistic regression was used to identify independent predictors of positive surgical margins. RESULTS: A total of 1025 cases were available for analysis, of which 65 and 960 had positive and negative surgical margins, respectively. On univariate analysis, positive margins were associated with older age (64.3 vs. 59.6, p<0.01), history of prior ipsilateral kidney surgery (13.8% vs. 5.6%, p<0.01), lower preoperative eGFR (74.7 mL/min/1.73 m2 vs. 81.2 mL/min/1.73 m2, p=0.01), high tumor complexity (31.8% vs. 19.0%, p=0.03), hilar tumor location (23.1% vs. 12.5%, p=0.01), and lower surgeon volume (p<0.01). Robotic versus open approach was not associated with the risk of positive margins (p=0.79). On multivariable analysis, lower preoperative eGFR, p=0.01), hilar tumor location (p=0.01), and lower surgeon volume (p<0.01) were found to be independent predictors of positive margins. CONCLUSION: In our large institutional series of partial nephrectomy cases, patient, tumor, and surgeon factors influence the risk of positive margins. Of these, surgeon volume is the single most important predictor of surgical margin status, indicating that optimal oncological outcomes are best achieved by high-volume surgeons.

cT1a Renal Masses Less Than 2 versus 2 cm or Greater Managed by Robotic Partial Nephrectomy: A Propensity Score Matched Comparison of Perioperative Outcomes.

PURPOSE: We performed a single center evaluation to compare perioperative, pathological and functional outcomes of robotic partial nephrectomy of T1a renal masses less than vs greater than 2 cm. MATERIALS AND METHODS: Propensity score 1:1 matching of queried patients was performed using the institutional robotic partial nephrectomy database from January 2007 to January 2017. Matching was done by patient age, gender, race, body mass index, the Charlson comorbidity index, smoking status, diabetes, hypertension, hyperlipidemia, ASA® (American Society of Anesthesiologists®) score, estimated glomerular filtration rate, chronic kidney disease stage and R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar line and abutting main renal artery or vein) score. We analyzed the records of 524 patients, including 262 with a renal mass less than 2 cm vs 262 with a renal mass 2 cm or greater. Perioperative, pathological and functional outcomes were evaluated. RESULTS: Smaller renal masses (less than 2 cm) were associated with significantly lower operative time, blood loss, ischemia time (mean ± SD 14.3 ± 9.58 vs 21.5 ± 9.51 minutes, p <0.001) and intraoperative transfusions (0% vs 2.7%, p = 0.015). Moreover, we found superior early renal functional outcomes as assessed by the estimated glomerular filtration rate on postoperative day 1 (mean 83.1 ± 21.3 vs 76.6 ± 22.0 mg/ml/1.73 m, p = 0.001), greater parenchymal preservation (mean 89.9% ± 9.45% vs 83.6% ± 8.20%, p <0.001) and a trend toward a lower rate of postoperative complications (13.5% vs 19.5%, p = 0.080). A higher incidence of malignancy was found in larger tumors (85.9% vs 74.8%, p = 0.002) but no difference was recorded in positive surgical margins. CONCLUSIONS: Robotic partial nephrectomy tends to be a low morbidity treatment modality for renal masses less than 2 cm. Although active surveillance is a common option for such tumors, robotic partial nephrectomy remains an alternative in select patients.

Renal Arterial Pseudoaneurysm After Partial Nephrectomy: Literature Review and Single-Center Analysis of Predictive Factors and Renal Functional Outcomes.

INTRODUCTION AND OBJECTIVE: Partial nephrectomy (PN) represents the current surgical standard for T1 tumors. Renal arterial pseudoaneurysm is a rare but potentially life-threatening complication reported after PN. The aim of this study was to identify the factors associated with the occurrence of pseudoaneurysm after PN, specifically focusing on those requiring management with selective embolization. A literature review of the topic was performed. METHODS: A retrospective review of the institutional PN database was performed from January 2011 to December 2016. Patients who underwent embolization for pseudoaneurysm represented a separated cohort to be compared with other patients (controls). Patients' and tumors' characteristics were considered. Univariable and multivariable analyses were used to test their eventual association with the occurrence of pseudoaneurysm. RESULTS: A total of 1417 cases were evaluated. At a median of 21 days (interquartile range = 10-34), 20 patients (1.4%) developed postoperative pseudoaneurysm. The majority of patients (70%) presented with gross hematuria. The clinical suspicion was confirmed by contrast-enhanced computed tomography scan with angiography. Selective embolization was performed using endovascular coils. Technical success and clinical success rates were 100% and 95%, respectively. No difference was found in percentage estimated glomerular filtration rate (eGFR) preserved between patients who underwent embolization versus controls (median 82.6% versus 86.3%, P = .35). No differences in age, baseline renal function (as assessed by glomerular filtration rate [GFR]), tumor size, and R.E.N.A.L. were found between patients who reported and did not report pseudoaneurysm. In patients who developed pseudoaneurysm, longer operative time (225.6 minutes versus 193 minutes, P = .04), and cold ischemia time (48 minutes versus 29 minutes, P = .03) were reported. CONCLUSION: In our series, the occurrence of pseudoaneurysm was associated with longer operative and cold ischemia times. In patients who underwent selective embolization, renal function remained comparable with that of controls.

Achieving tumour control when suspecting sinus fat involvement during robot-assisted partial nephrectomy: step-by-step.

OBJECTIVES: To report a single expert robotic surgeon's step-by-step surgical technique for achieving local cancer control during robot-assisted PN (RAPN) for T3 tumours. PATIENTS AND METHODS: Since January 2010 to December 2016, the institutional RAPN database was queried for patients who underwent transperitoneal RAPN performed by a single surgeon for tumours ≤4 mm from the collecting system at preoperative computed tomography (three points on the 'N [Nearness]' R.E.N.A.L. nephrometry-score item) that were pT3a involving sinus fat at final pathology. Baseline characteristics, perioperative and oncological outcomes (particularly positive surgical margins, PSMs), were identified. RESULTS: Of 1497 masses that underwent RAPN, 512 scored 3 points on the 'N' item of the R.E.N.A.L. nephrometry score assessment. In all, 24 patients had pT3a tumours involving sinus fat at final pathology and represented the analysed cohort. RAPN were performed according to the here described technique. No PSMs were reported. Trifecta achievement was 54.2%. Within a median follow-up of 30 months, two and one patients had recurrence or metastasis, respectively. Two patients died unrelated to renal cancer. Retrospective analysis and limited follow-up represent study limitations. CONCLUSION: In a selected cohort of patients with renal tumours near the sinus fat at baseline R.E.N.A.L. nephrometry score assessment and confirmed pT3a at final pathology, the described RAPN technique was able to achieve optimal local cancer control.

Robotic radical prostatectomy after aborted prostatectomy: still feasible? The experience from a tertiary care center.

To describe the surgical management of patients who had radical prostatectomy previously attempted but aborted due to diverse causes. Patients who underwent an "aborted prostatectomy" were extracted from the institutional prostatectomy database. A description of the tailored robotic approach was reported for each case. Tips and tricks for the accomplishment of robotic prostatectomy after aborted prostatectomy were reported. Six clinical cases were analyzed. Three patients had aborted prostatectomy due to complicated dissection hindered by pelvic mesh and bowel adhesions; one prostatectomy was aborted due to anesthesiology/respiratory matters; one for narrow pelvis; one due to abnormal pelvic vascular anatomy. All patients successfully underwent robotic prostatectomy at our institution. In five patients, standard transperitoneal robotic approach was performed. In one patient, robotic transperineal approach was mandatory. Median operative time was 282 min (86-460). Median estimated blood loss was 325 mL (50-1000). Two patients had positive surgical margins. One patient was found with nodal metastasis at final pathology. Neither perioperative nor postoperative complications were reported. At last follow-up, PSA was undetectable in 5/6 patients. Even after previous aborted prostatectomy, robot-assisted prostatectomy is feasible, with acceptable results. The case-by-case tailoring of the technique is the key for a successful intervention.

Variability in Partial Nephrectomy Outcomes: Does Your Surgeon Matter?

BACKGROUND: Understanding physician-level discrepancies is increasingly a target of US healthcare reform for the delivery of quality-focused patient care. OBJECTIVE: To estimate the relative contributions of patient and surgeon characteristics to the variability in key outcomes after partial nephrectomy (PN). DESIGN, SETTING, AND PARTICIPANTS: Retrospective review of 1461 patients undergoing PN performed by 19 surgeons between 2011 and 2016 at a tertiary care referral center. INTERVENTION: PN for a renal mass. OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS: Hierarchical linear and logistic regression models were built to determine the percentage variability contributed by fixed patient and surgeon factors on peri- and postoperative outcomes. Residual between- and within-surgeon variability was calculated while adjusting for fixed factors. RESULTS AND LIMITATIONS: On null hierarchical models, there was significant between-surgeon variability in operative time, estimated blood loss (EBL), ischemia time, excisional volume loss, length of stay, positive margins, Clavien complications, and 30-d readmission rate (all p<0.001), but not chronic kidney disease upstaging (p=0.47) or percentage preservation of glomerular filtration rate (p=0.49). Patient factors explained 82% of the variability in excisional volume loss and 0-32% of the variability in the remainder of outcomes. Quantifiable surgeon factors explained modest amounts (10-40%) of variability in intraoperative outcomes, and noteworthy amounts of variability (90-100%) in margin rates and patient morbidity outcomes. Immeasurable surgeon factors explained the residual variability in operative time (27%), EBL (6%), and ischemia time (31%). CONCLUSIONS: There is significant between-surgeon variability in outcomes after PN, even after adjusting for patient characteristics. While renal functional outcomes are consistent across surgeons, measured and unmeasured surgeon factors account for 18-100% of variability of the remaining peri- and postoperative variables. With the increasing utilization of value-based medicine, this has important implications for the goal of optimizing patient care. PATIENT SUMMARY: We reviewed our institutional database on partial nephrectomy performed for renal cancer. We found significant variability between surgeons for key outcomes after the intervention, even after adjusting for patient characteristics.

Robotic cold ischemia achieves comparable functional outcomes to open cold ischemia during partial nephrectomy for complex kidney tumors.

OBJECTIVES: To compare the perioperative and functional outcomes after open and robotic partial nephrectomy performed with cold ischemia. METHODS: A retrospective chart review was completed of consecutive patients who underwent partial nephrectomy with renal hypothermia between January 2011 and September 2016. The study cohort included both open (Open Cold Ischemia, OCI; n=170) and robotic (Robotic Cold Ischemia, RCI; n=31) patients with complex renal masses (R.E.N.A.L. score >7) who did not meet exclusion criteria. A modified intracorporeal technique 1 was utilized for the introduction of ice slush at the time of hilar clamping in the RCI group. Statistical testing was performed to compare key perioperative and functional outcomes after ensuring equilibration of both groups by clinicodemographic criteria. RESULTS: Both groups were statistically equivalent with respect to baseline characteristics. Median GFR preservation postoperatively was 86.7% for the open group and 86.6% in the robotic group (p=0.49). Cold ischemia time (CIT) in the open group was 35 minutes compared to 28 minutes (p = 0.03) in the robotic group. LOS was significantly shorter by 2 days (p < 0.01) in the robotic group. Positive margins was noted to be 17 (10%) in the open group and 2 (6.5%) patients in the robotic group (p=0.48). CONCLUSIONS: We demonstrate an effective and simplified method of intracorporeal ice cooling during robotic partial nephrectomy. Our data suggests that results with this approach compare favorably to open cold ischemia technique. Intracorporeal ice cooling can be considered when performing complex partial nephrectomies with ischemia times expected to exceed 25 minutes.

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.

Minimally Invasive Management of Ureteral Distal Strictures: Robotic Ureteroneocystostomy With a Bilateral Boari Flap.

OBJECTIVE: To describe robotic ureteroneocystostomy performed by bilateral Boari flap. METHODS: An 82-year-old female with bilateral mid ureteral strictures secondary to uterine cancer treated with radiation was managed with ureteral stenting and bilateral nephrostomy tubes. Nevertheless, patient had severe colic and recurrent urinary tract infections and thus agreed to undergo bilateral robotic ureteral reconstructive surgery. Patient positioning and ports placement were similar to those of robotic prostatectomy. Ureters were divided at the level of the common iliac bifurcation and mobilized proximally. Strictures were excised and ureters were spatulated. After the bladder was dropped from the abdominal wall, a bladder flap was created with a broad base to ensure adequate blood supply. The ureteral anastomosis to the bladder flap was started using 3-0 Vicryl interrupted sutures to secure the posterior ureter to the bladder flap. The flap was then bisected in the midline to create a tension-free anastomosis. The ureteral anastomosis was completed over a double J ureteral stent. The wings of the bisected bladder flap were reapproximated with a 3-0 barbed suture to form a "Y" bladder configuration. Procedures were done bilaterally. The remainder of the cystotomy was closed with barbed suture. The bladder was tested for leakages and a drain was placed. RESULTS: Blood loss was 50 mL. The patient recovered uneventfully and was discharged on postoperative day 4 with nephrostomy tubes and Jackson-Pratt drain removed prior to discharge. Follow-up cystogram revealed no leakage and bilateral reflux in the reconstructed bladder. Ureteral stents were removed 4 weeks postoperatively. Follow-up for these patients is recommended with either a renal scan or CT scan with delayed imaging. For this patient with severe chronic kidney disease, she unfortunately could not receive intravenous contrast and renal scan proved unreliable. Therefore, our follow-up was performed on the basis of her renal function (creatinine) which remained stable without nephrostomies or ureteral stents. Postoperatively, the patient did not complain of de novo lower urinary tract symptoms nor did she require anticholinergics. CONCLUSION: Robotic bilateral Boari flap is feasible for patients with bilateral distal ureteral strictures. Further studies are needed to assess long-term outcomes. Given the significant degree of bladder reconstruction required for this procedure, we recommend an assessment of bladder capacity preoperatively in the form of a gravity cystogram or video urodynamics.

Trifecta Outcomes in Renal Hilar Tumors: A Comparison Between Robotic and Open Partial Nephrectomy.

OBJECTIVES: To report a comparative analysis of outcomes in patients who underwent excisions of renal hilar tumors using both open and robotic approaches. MATERIALS AND METHODS: We retrospectively reviewed robotic and open patients who underwent partial nephrectomy of renal hilar tumors between 2011 and 2016. "Trifecta" was defined as negative surgical margins, no complications, and a glomerular filtration rate (GFR) preservation of ≥90% at last follow-up. Inverse probability of treatment weighting (IPTW) was applied to equilibrate treatment groups, minimize selection bias, and optimize inference on the basis of each patient's clinicodemographic characteristics. RESULTS: One hundred robotic and 64 open patients had sufficient data for IPTW. After weighting, there were no statistical differences in baseline characteristics between the two groups (p < 0.05). On adjusted analyses, robotic partial nephrectomy (RPN) achieved equivalent rates of trifecta to open surgery (21.1% vs 13.9%, respectively, p = 0.387). There were no differences between robotic and open cohorts for negative margin rates (72.8% vs 90.4%, p = 0.124), absence of complications (68.6% vs 75.2%, p = 0.587), or GFR ≥90% (39.4% vs 21.6%, p = 0.111). The robotic cohort had a shorter mean length of stay (3.8 vs 5.0 days, p = 0.012), and no difference in estimated blood loss (253.3 vs 357.1, p = 0.091) or operating time (199.8 vs 200.4, p = 0.961). CONCLUSIONS: In our analysis both open and RPN for hilar tumors were equally likely to achieve a low "trifecta" outcome with a shorter mean length of stay in the robotic cohort.

Infrared Light Structured Sensor Three-dimensional Approach to Estimate Kidney Volume: A Validation Study.

OBJECTIVE: To validate a new procedure for the three-dimensional estimation of total renal parenchyma volumeusing a structured-light infrared laser sensor. METHODS: To evaluate the accuracy of the sensor for assessing renal volume, we performed 3 experiments. Twenty freshly excised porcine kidneys were obtained. Experiment A, the water displacement method was used to obtain a determination of the renal parenchyma volume after immersing every kidney into 0.9% saline. Thereafter a structured sensor (Occipital, San Francisco, CA) was used to scan the kidney. Kidney sample surface was presented initially as a mesh and then imported into MeshLab (Visual Computing Lab, Pisa, Italy) software to obtain the surface volume. Experiment B, a partial excision of the kidney with measurement of the excised volume and remnant was performed. Experiment C, a renorrhaphy of the remnant kidney was performed then measured. Bias and limits of agreement (LOA) were determined using the Bland-Altman method. Reliability was assessed using the intraclass correlation coefficient (ICC). RESULTS: Experiment A, the sensor bias was -1.95mL (LOA: -19.5 to 15.59, R2 = 0.410) with slightly overestimating the volumes. Experiment B, remnant kidney after partial excision and excised kidneyvolume were measured showing a sensor bias of -0.5mL (LOA -5.34 to 4.20, R2= 0.490) and -0.6mL (LOA: -1.97.08 to 0.77, R2 = 0.561), respectively. Experiment C, the sensor bias was -0.89mL (LOA -12.9 to 11.1, R2= 0.888). ICC was 0.9998. CONCLUSION: The sensor is a reliable method for assessing total renal volume with high levels of accuracy.

Frozen Sections for Margins During Partial Nephrectomy Do Not Influence Recurrence Rates.

INTRODUCTION: Frozen sections (FS) are routinely employed to assess margin status during partial nephrectomy (PN) for clinically localized renal cell carcinoma (CLRCC); however, their oncologic benefit remains unclear. There have been no studies investigating the long-term impact of FS on local or metastatic recurrence. We wished to determine whether the utilization of FS for this purpose during PN influenced recurrence rates. MATERIALS AND METHODS: We performed a retrospective review of 1090 patients with (n = 172) and without (n = 918) FS during open and robotic PN between 2006 and 2016 for CLRCC at a single tertiary care institution. Standard follow-up protocols were employed, with imaging used to guide subsequent biopsy for confirmation. Univariate and multivariate competing-risk regression analysis predicting the association of FS status and clinicodemographic characteristics with recurrence, with adjustment for all-cause mortality, were performed. Administrative data were reviewed to calculate costs of FS. RESULTS: Forty-five out of 1090 (4.13%) patients had recurrence. There was no difference in the cumulative incidence of recurrence between patients with and without FS (χ2 = 0.001, p = 0.97). On multivariable competing risk analysis, FS was not associated with recurrence (hazard ratio [HR], 1.56; 95% confidence interval [CI], 0.65-3.76). However, tumor grade (g3-4 vs 1-2: HR, 2.45; 95% CI, 1.16-5.14) and stage (>pT2 vs pT1a: HR, 2.86; 95% CI, 1.13-7.26) were associated with recurrence. The average direct charge per patient undergoing FS was $902. CONCLUSIONS: Intraoperative FS for margins during PN did not predict decreased recurrence rates in a single-institution high-volume center. Given the lack of associated benefit, and the added cost, the utilization of FS during PN should be limited.

Cold Versus Warm Ischemia Robot-Assisted Partial Nephrectomy: Comparison of Functional Outcomes in Propensity-Score Matched "At Risk" Patients.

OBJECTIVES: To compare functional outcomes of warm ischemia RPN (wRPN) to cold ischemia RPN (cRPN) in "at risk" patients. MATERIALS AND METHODS: Retrospective review of institutional database queried for all patients who underwent cRPN/wRPN (January 2007-December 2016). For the study purpose, patients with solitary kidney and/or history of partial nephrectomy and/or multiple tumors and/or preoperative estimated Glomerular Filtration Rate (eGFR) <60 mL/minute were extracted. To reduce inherent biases, groups were matched on key variables related to renal function through a greedy matching algorithm with no replacement. Renal functional outcomes were evaluated by eGFR drops at 1-3 days and at 1, 3, 6, and 12 months postoperatively. A linear mixed effects model was used to assess eGFR at each follow-up who received either cRPN or wRPN. Follow-up was treated as a factor variable to account for nonlinear time trends. Contrast analysis was used to compare cRPN vs wRPN groups at each follow-up, using Sidak-Holm p-value adjustments for multiple comparisons. RESULTS: Out of 19 cRPN patients and 279 wRPN patients, 14 cRPN patients were finally matched 1:1 with no replacement to 14 wRPN. There was no significant difference in preoperative eGFR for matched patients undergoing cRPN vs wRPN. Since the first postoperative day, cRPN patients had higher eGFR. The difference was statistically significant since the third month postoperatively (mean difference = 18.201, 95% confidence interval [CI]: 1.930-34.472) and remained at both the sixth month (mean difference = 18.839, 95% CI: 2.568-35.109) and the 12th month (mean difference = 21.277, 95% CI: 5.006-37.547) follow-up. CONCLUSIONS: Accounting for unmodifiable and modifiable factors, in a cohort of highly selected patients "at risk" for postoperative significant decline in renal function after RPN, renal functional outcomes appear to be superior with cold ischemia technique.

Trifecta Outcomes in Multifocal Tumors: A Comparison Between Robotic and Open Partial Nephrectomy.

OBJECTIVES: To report a comparative analysis of outcomes in patients who underwent multiple excisions for unilateral synchronous multifocal renal tumors using both open and robotic approaches. METHODS: We retrospectively reviewed 110 patients who underwent robotic and open partial nephrectomy and had multiple tumor excisions in an ipsilateral kidney. "Trifecta" was defined as negative surgical margins, no urologic complications, and a glomerular filtration rate (GFR) preservation of ≥90% at last follow-up. Inverse probability of treatment weighting (IPTW) was applied to equilibrate treatment groups, minimize selection bias, and optimize inference on the basis of each patient's clinicodemographic characteristics. RESULTS: Sixty-eight robotic and 42 open patient approaches had sufficient data for IPTW. After weighting, there were no statistical differences in baseline characteristics between the two groups. On adjusted analyses, robotic partial nephrectomy achieved equivalent rates of trifecta to open surgery (16.3% vs 16.5%, p = 0.99), which persisted on subgroup analyses of patients with two (20.1% vs 23.7%, p = 0.82) or more than two tumors (6.8% vs 7.4%, p = 0.95). There were no differences between robotic and open cohorts for negative margin rates, absence of complications, or GFR ≥90%. The robotic cohort had a shorter mean length of stay (3.4 vs 4.9 days, p < 0.001). CONCLUSIONS: Surgical resection remains the mainstay for patients with unilateral, synchronous, and multifocal renal tumors. Our analysis found that both open and robotic approaches to partial nephrectomy are equally likely to achieve the "trifecta" outcome in an equilibrated high-risk group of patients. The robotic approach for these complex patients may be safe and feasible for a carefully selected group of patients.