Aaron Lay

MP75-12 PROSPECTIVE EVALUATION OF STONE FREE RATES BY COMPUTED TOMOGRAPHY AFTER AGGRESSIVE URETEROSCOPY

proximal or impacted stones. We examined whether a double drug Antibiotic Prophylaxis Treatment (APT), an aminoglycoside and penicillin based on resistant bacteria strains we encounter in our institution may reduce urosepsis post-ureteroscopy. METHODS: Between February 2015 and March 2016, we performed 344 ureteroscopies. Starting September, 2015 we changed the APT for endo-urological procedures according to the bacterial resistance profile in urine cultures at our institution. Inclusion criteria were adult patients referred to ureteroscopic treatment for a urinary stone, with or without prior stenting. Exclusion Criteria included integrated procedures (with PCNL), biopsies, pediatric or pregnant patients. Sepsis was defined as fever above 38.5 degrees Celsius with additional standard criteria (International Sepsis Definitions Conference). All patients had a urine culture taken prior to APT initiation. Fisher’s exact test and T-test with a two-tailed P value < 0.05 denoted statistical significance. RESULTS: 57 patients were excluded. Group 1 (n1⁄4106) were the last to receive the conventional APT (PO Ciprofloxacin 500mg X 2), while the second group (n1⁄4181) were the first to receive the new regimen (IV Gentamycin 240mg & Ampicillin 1gr X 3) prior to ureteroscopy. 65 patients had a preoperative positive culture. A significant percentage of both groups had a preoperative positive urine culture (29%-group 1; 18%-group 2). Seven out of 9 septic events developed in those patients (P<0.001). Patients undergoing RIRS procedures were at increased risk for a septic event when treated with conventional APT (7/9 events; P<0.01). No significant correlation was found between preoperative kidney drainage (stent or nephrostomy tube) and sepsis. CONCLUSIONS: Our study demonstrates that a significant portion of patients undergoing ureteroscopic treatment for urinary stones have positive preoperative urine culture, despite previous treatment. Standard, ‘one size fits all’ APT is not sufficient according to our data. A regimen tailored to the local bacterial resistance strains can lower the rate of sepsis significantly.

New therapies for castrate-resistant prostate cancer

Introduction: Prostate cancer is the second leading cause of cancer death in men in the USA, and most of these deaths will occur as a result of castrate-resistant prostate cancer (CRPC) that has progressed despite androgen deprivation therapy. There has been better understanding of castration resistance and molecular mechanisms of prostate cancer progression recently, leading to new treatment strategies. Areas covered: This review focuses on emerging and new therapies for castrate-resistant prostate cancer, including hormonal therapy, immunotherapy and cytotoxic agents. Expert opinion: New treatment strategies have been developed in recent years and, with improved understanding of advanced CRPC, additional targeted treatments are expected in the near future. Further cost effectiveness research of these treatments is warranted before dissemination of these promising agents.

MP22-11 PERFORMANCE OF MULTIPARAMETRIC MAGNETIC RESONANCE IMAGING TO IDENTIFY CLEAR CELL RENAL CELL CARCINOMA IN CT1A RENAL MASSES

patients referred for surgery while fear of biopsy-associated complications was the primary reason (58%) to decline RMB among those undergoing surveillance. Having an academic degree was associated with acceptance of a lower accuracy threshold (p1⁄40.03). Of the 59 participating urologists, 39% were reluctant to recommend RMB, primarily because of its inexorable non-diagnostic rate. CONCLUSIONS: Most patients and urologists would favor a RMB to facilitate their definitive treatment decision. Diagnostic accuracy of 95% was acceptable by the majority of study participants. The utility of RMB as part of the diagnostic algorithm for renal tumors should be discussed with patients, emphasizing its potential benefits and limitations.

MP100-11 PERCUTANEOUS IRREVERSIBLE ELECTROPORATION OF RENAL TUMORS: OUTCOMES AFTER MEDIAN 2 YEAR FOLLOW-UP

investigate the cost of pre-procedure biopsy of renal masses vs immediate cryoablation with intraoperative biopsy for patients with small renal masses who are candidates for cryotherapy. METHODS: We retrospectively identified all patients who had laparoscopic cryoablation for a renal tumor by a single surgeon at an academic center between 2004 and 2013. Pathology results from intraoperative biopsies were collected. Cost analysis was performed for two treatment algorithms. Algorithms differed in the initial step in management: CT guided biopsy vs laparoscopic cryoablation with intraoperative biopsy. RESULTS: There were 96 patients in the study. Pathology results from intraoperative biopsies were: Cancer: 64 (66.7%), Indeterminate: 12 (12.5%), and Benign: 20 (20.8%). Cost of laparoscopic cryoablation and hospital stay is

MP95-08 PRIMARY HYPERPARATHYROIDISM: A SOMETIMES ELUSIVE DIAGNOSIS

10,600. Cost of a CT guided biopsy is

MP68-13 OUTCOMES OF PATIENTS WITH RADIOGRAPHIC XANTHOGRANULOMATOUS PYELONEPHRITIS MANAGED WITH PERCUTANEOUS NEPHROLITHOTOMY

5,400. Cost of 5 years of surveillance is

MP90-14 DOES SATURATION INDEX PREDICT STONE ACTIVITY IN PATIENTS WITH CALCIUM OXALATE NEPHROLITHIASIS?

37,400. On average, the fiveyear cost to manage a patient initially with laparoscopic cryoablation is

155 THE INCIDENCE OF VTE AND MAJOR BLEEDING EVENTS IN MAJOR UROLOGIC SURGERY: A POPULATION-BASED ANALYSIS

40,200. This compares to

1078 RISK FACTORS FOR COMPLICATIONS AFTER PROSTATE BIOPSY AT THE VA

43,400 for CT guided biopsy as first management. In order for CT guided biopsy to be cost effective, 52% of small renal masses deemed appropriate for cryoablation would need to be benign. CONCLUSIONS: Immediate cryoablation is slightly more cost effective than getting a pre-operative CT guided biopsy for patients considering treatment of small renal masses with laparoscopic cryoablation. The cost difference is not enough to unilaterally drive clinical decisions but shared decision making should include cost. The overwhelming cost over five years is driven by cost of surveillance imaging.

PD45-02 NATURAL HISTORY OF RESIDUAL FRAGMENTS CONFIRMED BY COMPUTED TOMOGRAPHY AFTER URETEROSCOPY

RESULTS: SA patients have an 8.9% incidence of nephrolithiasis, compared to 5.5% of the non-SA control (p<0.001). SA patients also have higher rates of metabolic comorbidities (p<0.001). After adjusting for age, gender and comorbidities, the risk of nephrolithiasis remained significantly increased in the SA group (hazard ratio [HR]1⁄41.35; 95% confidence interval [CI]1⁄41.23-1.47; p<0.001). Greater HRs of nephrolithiasis were observed for male patients (1.21; 95% CI1⁄41.09-1.35; p<0.001) and those aged 20-39 years (1.25; 95% CI1⁄41.06-1.46; p<0.01) in the SA cohort. Risk of nephrolithiasis in SA patients increased significantly with concomitant diabetes mellitus, hypertension, hyperlipidemia, and morbid obesity. CONCLUSIONS: The study provides evidence that patients with SA have an increased risk of subsequent nephrolithiasis compared with patients without SA. Young male SA patients with concomitant comorbidities are at the greatest risk for nephrolithiasis formation.