Paras Shah

Perioperative Outcomes of Laparoscopic Partial Nephrectomy Stratified by Body Mass Index.

BACKGROUND AND PURPOSE Increased body mass index (BMI) has been shown to have inferior perioperative outcomes in patients undergoing laparoscopic partial nephrectomy (LPN). The aim of this study was to determine the differences in perioperative outcomes for patients undergoing LPN in normal, overweight, and obese persons using established BMI risk categories. METHODS A retrospective review of 488 patients undergoing LPN was performed stratifying patients according to BMI of <25 kg/m(2), 25 to 30 kg/m(2), and >30 kg/m(2). The analysis of variance test, chi-square analysis, and bivariate regression models were used to compare comorbidities and perioperative outcomes among the groups. RESULTS One hundred and eighty nine of 369 patients were identified as being obese. Obese patients were found to have a significantly higher American Society of Anesthesiologists class (2.4 vs 2.1) than normal weight patients (P=0.03). No significant differences were demonstrated in estimated blood loss, operative time, transfusion requirement, or rate of conversion between the groups. In addition, there was no significant difference in cardiovascular, pulmonary, thromboembolic, or infectious complications between the groups. Obesity was significantly associated with bleeding necessitating angioembolization (P=0.033). CONCLUSION LPN demonstrates equivalent perioperative outcomes in normal, overweight, and obese patients. The minimally invasive approach achieves equivalent outcomes in patients undergoing major abdominal surgery although further studies of alternate procedures are needed to validate our findings.

Risk prediction models for cancer-specific survival following cytoreductive nephrectomy in the contemporary era

INTRODUCTION To develop a risk-stratification model for cancer-specific survival (CSS) following cytoreductive nephrectomy (CN) in the contemporary era. MATERIALS AND METHODS A retrospective review was performed of 313 patients who underwent CN for M1 renal cell carcinoma (RCC) from 1990 to 2010. To account for the introduction of targeted therapies, timing of surgery was classified as immunotherapy era (1990-2004) or contemporary era (2005-2010). Risk scores were developed to predict CSS using Cox proportional hazards regression models. RESULTS A total of 215 (69%) and 98 (31%) patients were treated in the immunotherapy and contemporary eras, respectively. Median follow-up among survivors was 9.6 years, during which time 291 patients died, including 279 from RCC. On multivariable analysis limited to preoperative features, age ≥ 75, (hazard ratio [HR] 1.9), female sex (HR 1.9), constitutional symptoms (HR 1.61), radiographic lymphadenopathy (HR 1.59), and IVC tumor thrombus (HR 1.65) were significantly associated with CSS. On multivariable analysis including pathologic features, the features above as well as coagulative necrosis (HR 1.51) and sarcomatoid differentiation (HR 1.44) were significantly associated with CSS (all P < 0.05). Risk scores were developed for each model and used to predict CSS according to era. Decision curve analysis revealed that the preoperative risk score conferred a net benefit over a treat-all or treat-none approach beyond a 1-year cancer-specific mortality threshold of 25%. CONCLUSIONS We developed risk scores to predict CSS for patients treated with CN in the contemporary era. Patients with poor predicted survival may consider avoiding CN as initial management.

Skin-to-tumor Distance Predicts Treatment Failure of T1A Renal Cell Carcinoma Following Percutaneous Cryoablation

OBJECTIVE To determine the impact of skin-to-tumor (STT) distance on the risk for treatment failure following percutaneous cryoablation (PCA). METHODS We retrospectively reviewed patients who underwent PCA with documented T1a recurrent renal cell carcinoma (RCC) at 2 academic centers between 2005 and 2015. Patient demographics, tumor characteristics, and perioperative and postoperative course variables were collected. Additionally, we measured the STT distance by averaging the distance from the skin to the center of the tumor at 0°, 45°, and 90° on preoperative computed tomography imaging. RESULTS We identified 86 patients with documented T1a RCC. The mean age at the time of surgery was 69 years (range: 37-91 years), and the mean tumor size was 2.7 cm (range: 1.0-4.0 cm). With a mean follow-up of 24 months (range: 3-63 months), 11 (12.8%) treatment failures occurred. Patients with treatment failure had significantly higher mean STT distance than those without: 11.0 cm (range: 6.3-20.1 cm) compared to 8.4 cm (range: 4.4-15.2 cm), respectively (P = .002). STT distance was an independent predictor of treatment failure (odds ratio: 1.32, 95% confidence interval: 1.04-1.69, P = .029). STT distance greater than 10 cm had a fourfold increased risk of tumor treatment failure (odds ratio: 4.43, 95% confidence interval: 1.19-16.39, P = .018). Tumor size, R.E.N.A.L. Nephrometry score, and number of cryoprobes placed were not associated with treatment failure. CONCLUSION STT, an easily measured preoperative variable, may inform the risk of RCC treatment failure following PCA.

PD62-10 IDENTIFICATION OF MOLECULAR BIOMARKERS OF CISPLATIN-BASED CHEMOSENSITIVITY IN PATIENTS UNDERGOING NEOADJUVANT CHEMOTHERAPY FOR MUSCLE-INVASIVE BLADDER CANCER

malignancies, however, its impact on muscle mass in MIUC patients is undefined. As neoadjuvant chemotherapy (NC) prior to radical cystectomy is the current standard of care in MIUC, our objective was to describe preoperative changes in body composition in patients receiving platinum-based NC. METHODS: Patients with cT2-4, N0-1, M0 UC of the bladder who underwent NC were retrospectively identified. Skeletal muscle index (SMI, cm^2/m^2) was calculated using validated methodology (cross sectional area of skeletal muscle/height^2 at L3) from pre(preNC) and post-NC (post-NC) computed tomography images. Patients were classified as being sarcopenic according to consensus definitions: Male: SMI <55 cm^2/m^2, Female: SMI <38.5 cm^2/m^2. Pre-NC and post-NC median body mass index (BMI) and SMI were compared using paired Wilcoxon signed rank tests. RESULTS: The cohort consisted of 26 patients, with a median age 70 years, including 7 females (27%). Chemotherapy regimens included dose-dense methotrexate, vinblastine, doxorubicin and cisplatin in 8 (31%), gemcitabine/cisplatin in 16 (62%) and gemcitabine/carboplatin in 1 (3.8%). Median number of cycles was 3.5 (range 2-6). Median preand post-NC BMI were 27.1kg/m^2 and 27.2kg/m^2 (p1⁄40.36). Median preand post-NC cross-sectional lumbar muscle area were 141 and 129.4 cm^2 (p<0.001). Median preand post-NC SMI were 49.2 and 44.5 cm^2/m^2 (p<0.001). Median % change in SMI was -6.4% (Figure). Pre-NC, 18 (69%) patients were sarcopenic vs. 21 (81%, p1⁄40.002) postNC. Percent change in SMI did not differ according to baseline sarcopenia status or number of chemotherapy cycles. CONCLUSIONS: Although BMI remained stable, we observed a significant decrease in lean muscle mass among MIUC patients treated with platinum-based NC prior to cystectomy, with an associated increase in the prevalence of sarcopenia. These patients may benefit from pre-habilitative interventions to mitigate lean muscle loss prior to cystectomy. The association of change in SMI with surgical outcome in this cohort is under investigation.

PD66-08 PARTIAL NEPHRECTOMY IS ASSOCIATED WITH INCREASED RECURRENCE RISK AMONG CLINICAL STAGE T1 UPSTAGED TO PATHOLOGIC T3A RENAL CELL CARCINOMA

RESULTS: The analytic cohort included 1525 and 935 patients undergoing PN and RN, respectively. Mean (SD) preoperative eGFR and tumor size were 72 (20) mL/min and 3.4 (1.9) cm, respectively, for patients undergoing PN, and were 65 (18) mL/min and 7.1 (3.8) cm, respectively, for patients undergoing RN. The model for PN included age, presence of a solitary kidney, smoking status, performance status, BMI, preoperative eGFR, tumor size, and open vs lap surgical approach (R1⁄40.78), while the model for RN included age, diabetes, BMI, preoperative eGFR, tumor size, and surgical approach (R1⁄40.68). Using the models, a 68 year-old, nonsmoking, non-diabetic, ECOG 0, binephric patient with a BMI of 20kg/m, a preoperative eGFR of 100mL/min, and a 6.5cm renal mass will have a predicted eGFR of 85 mL/min following open PN and 63 mL/min following laparoscopic RN at 1 year. If the patient was instead 50 years old, diabetic, with a preoperative eGFR of 80mL/min and a 2.5cm mass, predicted eGFR would be 78 mL/min following laparoscopic PN and 56 following laparoscopic RN at 1 year. CONCLUSIONS: We created a prediction tool for renal function following RN and PN. If validated, this tool may be useful during patient counseling by providing personalized predicted renal function outcomes.

MP08-12 MULTI-INSTITUTIONAL EVALUATION OF MRI AND FUSION BIOPSY IN CONFIRMATORY BIOPSY FOR ACTIVE SURVEILLANCE

INTRODUCTION AND OBJECTIVES: To provide standardization as prostate MRI becomes increasingly utilized, the Prostate Imaging-Reporting and Data System (PIRADS) was developed and has been modified to its latest version (v2). Using biopsy outcome as the standard, we examined the predictive accuracy of a PIRADS 4 or 5 read for clinically significant (Gleason 7+) PCa in a blinded fashion. METHODS: We reviewed our prospectively maintained database of consecutive men who underwent prostate MRI prior to biopsy between September 2014 and December 2015. A proportionally representative sample (based on the original clinical PIRADS v2 interpretation) was selected for re-examination (n1⁄432). The prostate MRIs for these patients were de-identified and were loaded by a blinded third party. Four radiologists of varying levels of experience independently interpreted all prostate MRI, blinded to all clinical information. An 00overread00 was defined as a PIRADS 4 or 5 read with biopsy result of benign prostate or Gleason 6 PCa. An 00under-read00 was defined as a PIRADS 1-3 read with resulting biopsy result of Gleason 7+ PCa. RESULTS: The distribution of accuracy is provided in Table 1. Accurate interpretation ranged from 56% (18/32) to 75% (24/32), and the differences among the radiologists were not significant (p1⁄40.48). The improvement of accuracy with a 00majority read00, as defined by two or more accurate radiologists0 blinded interpretations, over the original clinical read trends toward significance (p1⁄40.16). No clinical variable was predictive of an incorrect 00majority read00, including age, PSA, family history, use of 5-alpha reductase inhibitors, prostate volume, or previous biopsy history. CONCLUSIONS: In a blinded assessment of radiologists at our institution, we find that the predictive accuracy of PIRADS 4 or 5 for clinically significant PCa varies among radiologists independent of experience level. A 00majority read00 performed better than the original clinical interpretation, suggesting that consensus interpretation of prostate MRI may improve predictive accuracy.

PD41-10 EVALUATION OF THE FEASIBILITY OF REMOTELY MANUFACTURED LOW-COST THREE-DIMENSIONALLY PRINTED LAPAROSCOPIC TRAINERS AND COMPARISON TO STANDARD LAPAROSCOPIC TRAINERS

INTRODUCTION AND OBJECTIVES: Patient safety is fundamental to surgical practice and it is critical to ensure surgical training and competence. Little has been published on brain cognitive states during learning and retention of basic Robot-Assisted Surgical skills. We sought to evaluate the feasibility of utilizing a novel brain functional states to evaluate surgical competency. METHODS: 27 medical students were evaluated while performing four key tasks of the validated Fundamental Skills of Robot Surgery (FSRS) Curriculum and one advanced surgical module the Hands-on Surgical Training (HoST) over six sessions, utilizing the robotic Surgery Simulator (RoSS). The four FSRS tasks evaluated were Instrument Control Task, Ball Placement Task, Spatial Control II Task, Threading string through a series of hoops and 4th Arm Tissue Retraction. Tool -based metrics were assessed and recorded by RoSS. Brain states are extracted using the pairwise phase synchronization between EEG channels and are presented as functional brain networks. The functional brain networks are then quantified using network statistics, and spectral density of signals for all channels (mental workload). RESULTS: The average mental workload initially increases before significantly decreasing across sessions(Fig 1). This trend is also observed in functional brain states during the four tool-based metrics, as integration and segregation features increase at the beginning of learning and later decrease (Fig 2). We observed significant correlations between brain state and tool-based metrics (RoSS), while performing HOST task, where brain states do not correlate. CONCLUSIONS: We report to our knowledge, the first study that evaluates brain states during skill acquisition and learning after simulation-based training. Various brain areas are functionally activated and integrated while acquiring new skills but these interactions decrease after preliminary learning.

Ureteropelvic Junction Obstruction Secondary to Metastatic Relapse of Breast Cancer

We describe the case of a 53-year-old woman with a history of localized breast cancer who presented with flank pain and was found to have new-onset obstruction of the left ureteropelvic junction. Although initially believed to be unrelated to her history of prior malignancy, intraoperative assessment of tissue from the ureteropelvic junction during planned laparoscopic pyeloplasty revealed urothelial infiltration by carcinoma of breast origin.

MP51-18 POST PERCUTANEOUS NEPHROLITHOTOMY HEMORRHAGE: ASSESSMENT OF FACTORS ASSOCIATED WITH A NEGATIVE RENAL ANGIOGRAM

INTRODUCTION AND OBJECTIVES: The impact of percutaneous nephrolithotripsy (PCNL) on renal function is an especially important consideration in stone formers with solitary kidneys. The objectives of this study were to evaluate the effect of PCNL on kidney function and further characterize patient demographics and perioperative outcomes of this unique cohort. METHODS: A retrospective review of medical records was performed on patients with a solitary or single functioning renal unit who underwent PCNL at a single institution between 1990 and 2013. Data on early and long-term post-operative renal function were collected and analyzed. Patient demographics and perioperative factors were compared to our larger cohort of PCNL patients and evaluated as potential predictors of post-operative renal function. RESULTS: Of 2318 patients, there were 76 PCNL events for patients with a solitary renal unit (40 female and 36 male). Long-term data (over 2 years post-operatively) was available for 48 PCNL events (24 female and 24 male). Estimated glomerular function (eGFR) slightly worsened in the early post-operative period, from 51 2.9 to 47 2.7 ml/min/1.73m2 (p <0.01). In the long-term however, eGFR improved, from 48 3.7 to 57 5.9 ml/min/1.73m2 (p <0.02). Predominant stone compositions included 19.7% cysteine, 19.7% calcium oxalate monohydrate and 11.8% and struvite. Compared to the larger cohort of PCNL patients, age, sex, complications, and stone free rates were consistent. Patients with solitary kidneys had more medical co-morbidities (64.7% vs 45%), with higher rates of diabetes (18.4% vs 13%) and pre-existing renal impairment (18.4% vs 3%). Univariate analyses of patient age, sex, comorbidities, stone composition, stone size, number of tracts and stone free rates were unable to identify a significant predictor of early and long-term postoperative renal function. CONCLUSIONS: These results show that while in the early post-operative period renal function slightly declines, it recovers in the long-term post PCNL for patients with solitary kidneys. Based on these findings, PCNL correlates with overall improved long-term renal function in patients with solitary kidneys. Given the higher rate of pre-existing medical co-morbidity and likely history of recurrent stone disease (high rates of cysteine and struvite stones), this solitary kidney cohort is presumably a high-risk population for future renal impairment. This further emphasizes the need to preserve renal function with PCNL in stone formers with solitary kidneys.

PD17-02 THE USE OF CYTOLOGY DURING THE WORKUP OF PATIENTS WITH PRIMARY MICROSCOPIC HEMATURIA: GUIDELINE COMPLIANCE PATTERNS AMONG A COHORT OF ACADEMIC UROLOGISTS

INTRODUCTION AND OBJECTIVES: In an effort to improve patient autonomy, several organizations publish online data on surgeon performance. One such organization is Pro-Publica, an independent nonprofit newsroom that publishes an online 0surgeon scorecard.0 This scorecard reports calculated death and complication rates for surgeons performing elective procedures including radical prostatectomy in Medicare patients. We wanted to understand how the general public would interpret this data and how it would impact patients’ selection of surgeon. METHODS: 265 adults at the Minnesota State Fair were asked to interpret a representative image from the Pro-Publica surgeon scorecard. Participants were told that a loved one had already scheduled cancer surgery with a surgeon they trusted. They were then shown a graphic with a dot representing the point estimate complication rate and a bar representing the 95% confidence interval (CI) of their surgeon. They were also shown a graphic with 13 other surgeons’ point estimate complication rates, all of which fell within the CI of the index surgeon’s complication rate. Another surgeon with a 0.5% lower point estimate but statistically equivalent complication rate to the first surgeon was indicated on the graphic. Participants were then asked if they would recommend switching surgeons after seeing this graphic. RESULTS: The surveyed population was educated with 89% having attended or graduated from college (n1⁄4235). Median age of participants was 50 years (range 20-74) with 68% females (n1⁄4179). Participants were from 136 different zip codes predominantly in the upper Midwest. When presented with the graphic representing two surgeons with different point estimate complication rates falling within the same confidence interval, 124 or 46.8% (95% CI 41-53) of respondents would recommend switching surgeons based on this single graphic. CONCLUSIONS: Nearly half of adults surveyed would recommend switching cancer surgeons for genitourinary malignancies based on a graphical representation of surgeons’ complication rates even though there was no statistically significant difference between the two surgeons. This suggests that simplistic displays of complicated statistical data may lead to changes in medical decision-making based on random error of measurement instead of true differences in surgeon quality.