The incidence, pathogenesis, and management of non-clear cell renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common type of kidney cancer and is divided into two distinct subtypes, clear cell renal cell carcinoma (ccRCC) and non-clear cell renal cell carcinoma (nccRCC). Although many treatments exist for RCC, these are largely based on clinical trials performed in ccRCC and there are limited studies on the management of nccRCC. Non-clear cell RCC consists of multiple histological subtypes: papillary, chromophobe, translocation, medullary, collecting duct, unclassified, and other rare histologies. Due to variations in pathogenesis and therapeutic response, therapy should be tailored to specific variant histologies. For patients with localized nccRCC, surgical resection remains the gold standard. In the metastatic setting, the standard of care has yet to be clearly defined, and most guidelines recommend clinical trial participation. General therapeutic options include immunotherapy, either as monotherapy or in combination, targeted therapies such as vascular endothelial growth factor tyrosine kinase inhibitors and MET inhibitors, and chemotherapy in certain subtypes. Here we present a review of the incidence and pathogenesis of the various subtypes, as well as available clinical data to support therapeutic recommendations for these subtypes. We also highlight currently available clinical trials in nccRCC and future directions in investigating novel treatment modalities tailored to patients with variant histology.

Cost and utilization analysis of concurrent versus staged testicular prosthesis implantation for radical orchiectomy.

PURPOSE: American Urological Association guidelines recommend testicular prosthesis discussion prior to orchiectomy. Utilization may be low. We compared outcomes and care utilization between concurrent implant (CI) and staged implant (SI) insertion after radical orchiectomy. MATERIALS & METHODS: The MarketScan Commercial claims database (2008-2017) was queried for men ages >18 years who underwent radical orchiectomy for testicular mass, stratified as orchiectomy with no implant, CI, or SI. 90-day outcomes included rate of reoperation, readmission, emergency department (ED) presentation, and outpatient visits. Regression models provided rate ratio comparison. RESULTS: 8803 patients (8564 no implant, 190 CI, 49 SI; 2.7% implant rate) were identified with no difference in age, Charlson Comorbidity Index, insurance plan, additional cancer treatment, or metastasis. Median perioperative cost at orchiectomy (+/- implant) for no implant, CI, and SI were $5682 (3648-8554), $7823 (5403-10973), and $5380 (4130-10521), respectively (p<0.001). Median perioperative cost for SI at implantation was $8180 (4920-14591) for a total cost (orchiectomy + implant) of $13650 (5380 + 8180). CI patients were more likely to have follow-up (p = 0.006) with more visits (p = 0.030) compared to the SI group post-implantation but had similar follow-up (p = 0.065) and less visits (p = 0.025) compared to the SI patients' post-orchiectomy period. Overall explant rates were 4.7% for CI and 14.3% for SI (p = 0.04) with a median time to explant of 166 (IQR: 135-210) and 40 days (IQR: 9.5-141.5; p = 0.06). Median cost of removal was $2060 (IQR: 967-2880). CONCLUSIONS: CI placement has less total perioperative cost, lower explant rate, and similar postoperative utilization to SI.

Predictive factors of diagnostic delay and effect on treatment patterns in testicular germ cell tumor patients.

BACKGROUND: Increased time from clinical symptom onset to diagnosis of testicular germ cell tumor (GCT), termed diagnostic delay (DD), is associated with an increased likelihood of metastatic disease at presentation. We assessed the association of patient factors on DD and subsequent treatment patterns. METHODS: The records for patients undergoing orchiectomy at a tertiary care hospital and safety net county hospital between 2006 and 2018 were obtained. Demographic variables, clinical symptoms, and post-diagnosis parameters were queried. Patient factors were assessed for association with DD by using both univariate and multivariable analyses. The effect of the Patient Protection and Affordable Care Act (PPACA) on DD was also studied. RESULTS: 201 patients received orchiectomy, and median DD was 38 days (IQR 14.5-122.5). Patients with metastatic disease had increased DD compared to those with localized disease (76 vs. 31 days, P < 0.001). Increased DD was associated with presentation to the safety net hospital (P = 0.001), non-white (P = 0.025), emergency department presentation (P = 0.025), uninsured (P = 0.01), testicular pain (P = 0.019), and presentation before 2014 (P = 0.047). DD was independently associated with presentation before 2014 (P = 0.004) on multivariate analysis. DD >38 days (i.e., above the median) was associated with increased receipt of adjuvant therapy (P = 0.001). CONCLUSION: PPACA implementation is associated with earlier detection of testicular cancer. Our findings highlight the impact of health care legislation on improving access of care to young men with cancer. Delay in diagnosis can lead to increased stage at presentation and need for adjuvant treatment. Further research to identify and overcome sociodemographic factors associated with diagnostic delay may lead to decreased treatment-related morbidity.

The early impact of medicaid expansion on urologic malignancies in the United States.

PURPOSE: To assess the effects of variable adoption of Medicaid Expansion (ME) of the Affordable Care Act among different states on urologic malignancies using a new variable that defines ME status of patient's residence in a nationwide cancer registry. BASIC PROCEDURES: The National Cancer Database was queried for urologic malignancies (bladder, prostate, kidney and testis) from 2011 to 2016, spanning the period surrounding the primary ME which took place in 2014. Trends in insurance status at time of diagnosis and effects on stage at presentation and survival after ME were evaluated using a difference-in-differences estimator and stratified Cox proportional hazards regression model. MAIN FINDINGS: The percentage of patients with Medicaid coverage at the time of diagnosis increased significantly after adoption of ME in ME states across all urologic malignancies. Concurrently, there was a significant decrease in percentage of uninsured patients diagnosed with testis cancer, but not other urologic malignancies, in ME states. A change in the stage at presentation was not observed across all urologic malignancies for patients in ME states after adoption of ME. No difference in overall survival was noted among patients living in a ME state compared to non-ME states with adoption of ME in 2014. PRINCIPAL CONCLUSIONS: Despite increases in the proportion of patients with Medicaid coverage after 2014 in states that enrolled in ME, there was not an associated change in stage at presentation or survival for patients with genitourinary malignancy.

Perioperative outcomes and cost of robotic vs open simple prostatectomy in the modern robotic era: results from the National Inpatient Sample.

OBJECTIVES: To perform a comparative analysis of perioperative outcomes and hospitalisation cost between open (OSP) and robot-assisted simple prostatectomy (RASP) for treatment of benign prostatic hyperplasia (BPH) using the National Inpatient Sample (NIS) in the contemporary robotic era. MATERIALS AND METHODS: The NIS was queried for cases of OSP and RASP for the treatment of BPH between 2013 and 2016. Perioperative complications, unadjusted hospital cost and length of stay (LOS) were compared between RASP and OSP. Smoothed linear regression curves comparing hospitalisation cost by increasing LOS was stratified by surgical approach to identify point of cost equivalency between RASP and OSP. Multivariable linear regression analysis was used to construct a hospitalisation cost model to examine the contribution of the robotic approach and LOS to hospitalisation cost. RESULTS: The total analytical cohort included 2551 OSP and 704 RASP procedures. Patients undergoing RASP were younger, at a median (interquartile range [IQR]) age of 68 (63-73) vs 71 (65-77) years, and with less comorbidity (76.8% vs 86.5%, P < 0.01). RASP was associated with fewer total complications (11.1% vs 29.2%, P < 0.01) and a greater likelihood of routine discharge to home rather than another facility (88.9% vs 76.7%, P < 0.01). While LOS was shorter with RASP (median [IQR], 2 [1-3] vs 4 [3-6] days, P < 0.01), total unadjusted hospitalisation cost (in United States dollars) was greater (median [IQR], $10 855 [$7965-$15 675] vs $13 467 [$10 572-$17 722], P < 0.01). Presence of any complication increased both LOS and hospitalisation cost (P < 0.01). Linear regression modelling determined the point of cost equivalence between RASP staying a median of 2 days was an OSP case staying between 5 and 6 days. On multivariable regression analysis, the robotic approach contributed an additional $6175 (P < 0.01) to the cost model, whereas each additional day of hospitalisation contributed $1687 (P < 0.01), suggesting LOS would need to be 3-4 days shorter with RASP to offset surgical costs of the robot. CONCLUSIONS: While RASP appears to have significantly better perioperative complication rates with shorter LOS and likely discharge to home, total hospitalisation cost remained greater, likely related to upfront operative costs. While this retrospective study is limited by selection bias for patients undergoing RASP, the benefits of improved convalescence, discharge to home, and lower rate of perioperative complications appear to justify performance of RASP in an experienced pelvic robotic centre despite relatively greater hospitalisation cost if referral to an experienced holmium laser enucleation of the prostate centre is not feasible.

Population-based analysis of cost and peri-operative outcomes between open and robotic primary retroperitoneal lymph node dissection for germ cell tumors.

PURPOSE: To compare perioperative outcomes and perform the first cost analysis between open retroperitoneal lymph node dissection (O-RPLND) and Robotic-RPLND (R-RPLND) using a national all-payer inpatient care database. METHODS: Nationwide Inpatient Sample (NIS) was queried between 2013-2016 for primary RPLND and germ cell tumor. We compared cost, length of stay (LOS), and complications between O-RPLND and R-RPLND. Linear regression plots identified point of cost equivalence between R-RPLND and O-RPLND. A multivariable linear regression model was generated to analyze predictors of cost. RESULTS: 44 cases of R-RPLND and 319 cases of O-RPLND were identified. R-RPLND was associated with lower rate of complications (0% vs. 16.6%, p < 0.01) and shorter LOS [Median (IQR): 1.5 (1-3) days vs. 4 (3-6) days, p < 0.01]. Rates of ileus, genitourinary complications, and transfusions were lower with R-RPLND, but did not reach significance. On multivariable analysis, robotic approach independently contributed $4457, while each day of hospitalization contributed to an additional $2,431 to the overall model of cost. Linear regression plots determined point of cost equivalence between an R-RPLND staying a mean of 2 days was 4-5 days for O-RPLND, supporting the multivariable analysis. Total hospitalization cost was equivalent between R-RPLND and O-RPLND [Median (IQR): $15,681($12,735-$21,596) vs $16,718($11,799-$24,403), p = 0.48]-suggesting that the cost equivalency of R-RPLND is, at least in part, attributable to shorter LOS. CONCLUSION: While O-RPLND remains the gold standard and this study is limited by selection bias of a robotic approach to RPLND, our findings suggest primary R-RPLND may represent a cost-equivalent option with decreased hospital LOS in select cases.

Impact of circulating microRNA test (miRNA-371a-3p) on appropriateness of treatment and cost outcomes in patients with Stage I non-seminomatous germ cell tumours.

OBJECTIVES: To determine whether utilisation of a serum microRNA (miRNA) test could improve treatment appropriateness and cost-effectiveness for patients with Stage I non-seminomatous germ cell tumours (NSGCTs). PATIENTS AND METHODS: A decision tree model was built to investigate treatment course, clinical and cost outcomes for patients with Stage IA (T1N0M0S0) and IB (T2-4N0M0S0) NSGCT. The model compared outcomes and cost of standard approach using histopathology, conventional serum tumour markers and radiographic staging (standard model) to a miRNA-based approach using the standard model + post-orchidectomy serum miR-371a-3p (marker model). Probabilities of expected treatment and outcomes were based on presence/absence of cancer upon entering into the model. Overtreatment was defined as adjuvant chemotherapy or primary retroperitoneal lymph node dissection in a patient without cancer. Undertreatment was defined as initial surveillance for a patient with cancer. RESULTS: Utilising the miRNA marker-based approach, 26% of patients avoid overtreatment and 8% avoid undertreatment in Stage IA NSGCT; 27% avoid overtreatment and 23% avoid undertreatment in Stage IB disease. Appropriate treatment decision-making increased from 65% to 94% and 50% to 92% for Stage IA and IB, respectively. The miRNA-based approach remained cost-effective over a wide range of performance characteristics with savings of ~$1400 (American dollars)/patient for both Stage IA and IB disease. CONCLUSION: A miRNA-based approach may potentially select patients with Stage I NSGCT for correct treatment in a cost-effective manner. Identification of residual teratoma-only remains an issue. Prospective studies are necessary to validate these findings.

Management of Stage II Germ Cell Tumors.

There are several treatment approaches for stage II germ cell tumors (GCTs), and a thorough understanding of the staging classification and histologic differences in tumor biology and therapeutic responsiveness is critical to determine an effective, multimodal management strategy that involves urologists, medical oncologists, and radiation oncologists. This article discusses contemporary management strategies for stage II GCTs, including chemotherapy, radiotherapy, retroperitoneal lymph node dissection (RPLND), and surveillance. Patient selection, histology, and extent of lymphadenopathy drive management, and, as both treatment and detection strategies continue to emerge and be refined, the management of patients with stage II GCT continues to evolve.

Robotic-assisted pyeloplasty:recent developments in efficacy, outcomes, and new techniques.

Within the last decade, the adaptation of robotic urologic surgery has had a profound impact on surgical practice, with robotic upper tract reconstruction for ureteropelvic junction obstruction gaining rapid acceptance. Recent advances in robotic reconstruction demonstrate efficacious outcomes of robotic pyeloplasty, as compared with conventional laparoscopic pyeloplasty, even in the case of secondary surgery. Furthermore, efforts to continue to reduce the morbidity of laparoscopic surgery have led to the development and implementation of laparoendoscopic single-site (LESS) surgery. The recent applications of the da Vinci robotic surgical platform to LESS pyeloplasty (R-LESS) has demonstrated the potential to further decrease morbidity, improve surgeon ergonomics, and improve cosmesis.

Residual fragments after percutaneous nephrolithotomy: cost comparison of immediate second look flexible nephroscopy versus expectant management.

PURPOSE: We performed a cost comparison of immediate second look flexible nephroscopy vs expectant management for post-percutaneous nephrostolithotomy residual fragments. MATERIALS AND METHODS: We used a decision analysis model to compare the cost of managing residual fragments by second look flexible nephroscopy vs observation. Outcomes of residual fragments after percutaneous nephrostolithotomy were determined from institutional experience and published shock wave lithotripsy series. Cost data were obtained from billing records. One-way sensitivity analysis was done to evaluate incurred costs of second look flexible nephroscopy while varying the likelihood of a stone event, the probability of surgery and the cost of surgical intervention. Two-way sensitivity analysis was done to assess the model across a range of scenarios. RESULTS: Based on data in the literature and our institutional experience 40% of patients with residual fragments 4 mm or less had a stone event, of whom 57% required surgical intervention. Based on these estimates the average cost of expectant management for a residual fragment 4 mm or less vs greater than 4 was $1,743 vs $4,674. The average incremental cost of second look flexible nephroscopy at our institution was $2,475. Two-way sensitivity analysis showed that varying assumptions dramatically altered conclusions about the cost benefit of second look flexible nephroscopy. CONCLUSIONS: Our model suggests that second look flexible nephroscopy is not cost advantageous in all patients with post-percutaneous nephrostolithotomy residual fragments. Cost benefit analysis is significantly impacted by the likelihood of a stone related event, the need for surgical intervention and surgical costs. Compared to an observational strategy second look flexible nephroscopy incurs lower costs for greater than 4 mm but not for 4 mm or less residual fragments.

Predictors of cost and clinical outcomes of percutaneous nephrostolithotomy.

PURPOSE: There is a paucity of information on the association of preoperative parameters with surgical outcomes and cost. We identified preoperative predictors of direct cost and examined the association of these factors with the perioperative outcomes of percutaneous nephrostolithotomy. MATERIALS AND METHODS: We reviewed the records of 200 consecutive patients who underwent percutaneous nephrostolithotomy at our hospital from September 2005 to May 2007. Complete cost and clinical information were available on 179 patients (89.5%). Patient and stone characteristics, and perioperative outcomes were recorded. Direct and component costs, including room and board, laboratory, pharmacy, radiology, operating room, surgical supplies, anesthesia and recovery room, were obtained from our hospital billing department. Univariate and multivariate linear regression analyses were performed to identify preoperative predictors of cost. We evaluated the association of independent predictors of cost with perioperative outcomes. RESULTS: On univariate analysis stone size category, preoperative urinary tract infection and allopurinol were associated with direct cost. On multivariate analysis only stone burden was an independent predictor of nephrostolithotomy cost. Large stone burden was associated with an increased need for multiple access (p = 0.0003), longer operative time (p <0.0001), longer hospitalization duration (p <0.0001), a lower stone-free rate (p = 0.038) and the need for second look flexible nephroscopy (p = 0.0005). Large stone burden was not associated with a greater transfusion requirement (p = 0.25) or an increased complication rate (p = 0.46). CONCLUSIONS: A large stone burden independently predicts higher costs in patients who undergo percutaneous nephrostolithotomy despite no associated increase in the complication or transfusion rate. Other patient characteristics, including age, body mass index and comorbidity status, do not increase cost.

Impact of body mass index on clinical and cost outcomes after radical cystectomy.

OBJECTIVE: To evaluate the effect of body mass index (BMI, kg/m(2)) on the cost and clinical variables after radical cystectomy (RC), as studies show that obesity might adversely affect the outcomes after RC. PATIENTS AND METHODS: The charts of patients who had RC from January 2004 to March 2007 were reviewed retrospectively. Complete cost and clinical information was available for 99 patients; the patient and tumour characteristics and peri-operative outcomes were recorded. Detailed cost information (room and board, laboratory, pharmacy, radiology, operating room, surgical supply, anaesthesia, and recovery room) was obtained from hospital billing. Patients were stratified and compared in three groups of BMI, i.e. normal weight (<25), overweight (25-<30) and obese (> or =30). RESULTS: The mean age of the patients was 66 years; 27% were normal weight, 38% were overweight and 34% were obese. Of obese patients, 24% had an Eastern Cooperative Oncology Group performance score of 0, vs none and 2.6% in the normal and overweight groups, respectively (P = 0.001). Those of normal weight had the highest overall and major complication rates (P = 0.57 and 0.28, respectively). Obese patients had insignificantly higher transfusion rates (P = 0.28). The direct cost was higher in normal weight ($14,314) than overweight ($13,808) and obese ($13,666) patients (P = 0.47). Higher room and board cost in normal-weight patients was the only significant cost difference (P = 0.008). CONCLUSION: BMI was not associated with increased costs of cystectomy. The absence of differences in cost-related and clinical outcomes might be attributable to variable comorbidity among groups and the experience of a high-volume surgeon and staff at a tertiary-care referral centre that routinely cares for obese patients.

Synchronous bilateral percutaneous nephrostolithotomy: analysis of clinical outcomes, cost and surgeon reimbursement.

PURPOSE: We compared clinical outcomes, cost and physician reimbursement between simultaneous bilateral percutaneous nephrostolithotomy and theoretical matched staged bilateral percutaneous nephrostolithotomy. MATERIALS AND METHODS: Between September 2005 and May 2007 we performed 200 percutaneous nephrostolithotomies including 17 synchronous bilateral procedures. Complete clinical and cost information was available and recorded for 15 patients. To compare variables between comparable synchronous and staged bilateral percutaneous nephrostolithotomy 152 unilateral percutaneous nephrostolithotomies were used to obtain similar parameters that were then used to estimate the outcomes of theoretical staged bilateral percutaneous nephrostolithotomy. Operative time, hospital length of stay, cost and physician reimbursement were determined according to CPT codes for stone complexity (50080 for stones less than 2 cm, 50081 for stones 2 cm or greater) to match case complexity per renal unit. RESULTS: Mean patient age (+/-SD) in the synchronous bilateral percutaneous nephrostolithotomy group was 51 (+/-11) years and 25% of patients had staghorn calculi. The stone-free rate after the initial procedure was 27% (4 of 15) and second look nephroscopy was performed in 10 patients. Complications occurred in 4 patients and none required transfusion. Mean overall cost of synchronous bilateral percutaneous nephrostolithotomy was $10,129. Cumulative room time, length of stay and cost were higher in the staged than synchronous percutaneous nephrostolithotomies. Physician reimbursement was 11% to 46% less for synchronous bilateral percutaneous nephrostolithotomy. CONCLUSIONS: Synchronous bilateral percutaneous nephrostolithotomy benefits patients and third party payors by decreasing cumulative operating room time, length of stay and cost. However, there is a disincentive for surgeons, who are financially penalized for performing synchronous bilateral percutaneous nephrostolithotomy. Third party payors should consider revising putative reimbursement policies for synchronous bilateral percutaneous nephrostolithotomy as it is cost-effective in appropriate patients.

Impact of body mass index on cost and clinical outcomes after percutaneous nephrostolithotomy.

OBJECTIVES: To evaluate the impact of body mass index (BMI) on clinical outcomes and costs associated with percutaneous nephrostolithotomy (PCNL). METHODS: We reviewed charts of 200 consecutive patients who underwent PCNL between September 2005 and May 2007. We recorded patient and stone characteristics and perioperative outcomes. BMI was available for 150 patients (75%), who comprised our study group. We obtained direct and subcomponent costs (room and board, laboratory, pharmacy, radiology, operating room, surgical supplies, anesthesia, and recovery room). We divided patients into four BMI categories: normal weight (BMI < 25), overweight (25 or= 40). We compared groups with regard to baseline characteristics, intraoperative parameters, stone-free and complication rates, and hospital length of stay. RESULTS: Mean stone size and proportion of patients with staghorn, multiple, and bilateral calculi were similar among groups. The normal weight cohort had proportionately fewer recurrent stone formers and patients with a history of stone surgery, compared with the other groups (P = .005 and P = .03, respectively). We found no significant differences among groups with regard to stone-free and complication rates, operative time, length of stay, or need for multiple accesses. Median direct cost was marginally, but not significantly, higher in normal weight ($8124) compared with overweight ($6746), obese ($6740), and morbidly obese ($6719) patients (P = .75). CONCLUSIONS: Body mass index had no impact on efficacy or complication rates of PCNL. Despite greater perceived difficulty in performing these procedures in overweight and obese patients, it was not more costly.

Are urologists fairly reimbursed for complex procedures: failure of 22 modifier?

OBJECTIVES: The 22 modifier was designed to provide surgeons with additional reimbursement for performing complex procedures. We evaluated whether urologists at a tertiary referral center are reimbursed when using the 22 modifier. METHODS: We evaluated the charts and billing data of all adult urology noncharity cases using the 22 modifier from January 2006 and September 2007. RESULTS: The 22 modifier was used in 317 of 7494 (4.2%) unique procedures performed. Of these 317 procedures, 99 (31%) were reimbursed at a greater rate than the contract level, with a mean increase greater than the contract of $388 (median $260, range $62-$3524), for a mean of 28% greater than the contract. Of the 317 cases, 114 were within $50 of the contract level and 104 were reimbursed at less than the contract level. Additionally, 56 cases were paid at the initial request and < or = 4 appeals were sent in 228 cases, with a successful result in 57 (25%). When analyzed by payor (n = 289), private insurance paid 81 of 187 (43.3%), Medicare paid 23 of 95 (24.2%), and Medicaid paid 1 of 7 (14.3%). Most payments took > 2 months to be paid. The reasons for using the 22 modifier code included extensive surgery, previous surgery, staghorn calculus, extended lymphadenectomy for bladder cancer, adhesions, difficult anatomy, complex dissection, morbid obesity, previous chemotherapy, scarring, previous radiotherapy, difficult debulking, and pregnancy. Of the 317 cases, > 121 had several confounding factors. CONCLUSIONS: The 22 modifier does not provide consistent reimbursement for urologists performing complex procedures. The long-term implications of financial disincentives to performing difficult surgeries need to be further evaluated.

Does obesity impact the costs of partial and radical nephrectomy?

PURPOSE: We analyzed the impact of obesity on the costs of partial and radical nephrectomy. MATERIALS AND METHODS: The charts of 237 patients who underwent open radical nephrectomy (48), laparoscopic radical nephrectomy (67), open partial nephrectomy (61) or laparoscopic partial nephrectomy (61) were retrospectively reviewed. Clinical data were collected, including age, American Society of Anesthesiologists score, body mass index, tumor size, complications and length of stay. Cost data comprised total direct costs and subcosts, including anesthesia, laboratory, operating room service, radiology, room and board, pharmacy and surgical supplies. Obese and nonobese patients were compared in each group using the Mann-Whitney U and chi-square tests for continuous and categorical variables, respectively. Univariate analysis was used to assess predictors of direct costs. RESULTS: Length of stay was longer in obese patients in the open partial nephrectomy group (p = 0.04). There were no differences between obese and nonobese patients in terms of complications and comorbidities. Costs were higher in obese patients in the open partial nephrectomy group ($10,187 vs $6,538, p = 0.02). There were no other differences in cost between obese and nonobese patients in the 3 other surgical groups. On univariate analysis length of stay robustly predicted the cost of each kind of operation (p <0.0001). Obesity status was almost a significant predictor of direct cost in the open partial nephrectomy group (p = 0.056). CONCLUSIONS: Body mass index had an impact on costs only in the subset of patients who underwent open partial nephrectomy. Length of stay seems to be the main determinant of costs in renal surgery. Further studies are warranted.