Source of Funding: none MP13-14 THE IMPACT OF SURGEON VOLUME ON THE MORBIDITY AND COSTS OF NEPHROURETERECTOMY IN THE UNITED STATES: A CONTEMPORARY POPULATION-BASED ANALYSIS Jeffrey Leow*, Joaquim Bellmunt, Toni Choueiri, Boston, MA; Benjamin Chung, Stanford, CA; Steven Chang, Boston, MA INTRODUCTION AND OBJECTIVES: Nephroureterectomy (NU), the standard treatment for upper tract urothelial carcinoma (UTUC), is associated with substantial morbidity and costs. This study evaluates the relationship between surgeon volume of NU and post- operative morbidity as well as the economic burden of bladder cancer in the United States. METHODS: We captured all patients who underwent a NU (ICD-9 code 55.51) with diagnoses of renal pelvis (189.1) or ureter (189.2) neoplasms from 2003 to 2010, using the Premier Comparative Database (Premier, Inc., Charlotte, NC), which collects data from over 600 non-federal hospitals throughout the US. Patient, hospital, and surgical characteristics were evaluated. Annual volume of NU for surgeons was divided into tertiles. Multivariable regression models were developed to evaluate outcomes including 90-day major com- plications (Clavien 3-5) and direct patient costs. We adjusted for patient (age, gender, race, Charlson comorbidity, insurance status), hospital (bedsize, teaching status, urbanicity, region) and surgical (year of surgery, lymphadenectomy, type of approach, hospital and surgeon volume) characteristics, including clustering by hospitals and survey weighting to achieve a nationally representative analysis. Various models including hospital and/or surgeon volume were performed. RESULTS: The weighted cohort included 49,009 NU patients with an overall 90-day major complication and readmission rate of 8.8% and 20.0% respectively. Compared to surgeons performing one NU annually, surgeons performing 3 NU each year had a 27% decreased odds of major complications (OR: 0.63, 95% CI: 0.40-0.98, p¼0.04). Compared to low volume hospitals (3/year), high volume hospitals (7/year) were associated with reduced costs by $1140 (p¼0.001). Compared to patients who did not have any complications, those who suffered a major complication had significantly higher 90-day median direct hospital costs ($31697 vs. $14690, p<0.0001). CONCLUSIONS: We demonstrate an inverse relationship between surgeon volume and the development of post-NU 90-day major complication rates. Surgeon volume appears to be a major driver for reducing morbidity while hospital volume drives reduction in costs. Centralization of NU to high volume surgeons at high volume hospitals may reduce the development of postoperative major complications and lessen the burden of UTUC on the health care system. Source of Funding: none MP13-15 EVOLUTIONARY STAGES IN URETHRAL STRICTURES Rajveer Purohit, Ricardo Georges*, Matthew Benedon, New York, NY; Gabriel Mekel, New york, NY; Jerry Blaivas, New York, NY INTRODUCTION AND OBJECTIVES: Currently, there is mini- mal data evaluating progression of urethral strictures (US) from early to advanced stages. We examined data on male patients presenting with incidental early stage US and tracked their stricture progression on subsequent cystoscopies using a validated stricture staging system. METHODS: This is a retrospective analysis of 25 men with incidental findings of early stage US on cystoscopy (CS) between 1999 and 2013 for urological conditions other than US and who had multiple CS as follow-up for their primary condition. Diagnoses of urethral strictures were made at the time of flexible cystoscopy according to a validated staging system: Stage 0 - no stricture; Stage 1-wide caliber stricture; Stage 2- requires gentle dilation with a flexible cystoscope; Stage 3-cannot be dilated but lumen is visible; Stage 4-no visible lumen. Our study evaluated patients with a Stage 1 stricture. No intervention was undertaken to treat the US in any of our patients. RESULTS: 33 patients were evaluated, 7 were excluded due to lack of follow up cystoscopies for a total of 25 men aged 44 to 88 (mean and median: 66) at the time of diagnosis. Mean number of cystoscopies (CS) were 9 (range: 2-46; median: 5); 12 for bladder cancer follow-up, 5 for suspected US, 4 for prostatic obstruction, and 1 each for several other diagnoses. 5 patients had more than one reason for initial CS. Overall, 6 progressed (24%), 6 regressed (24%) and 13 patients remained the same (52%). Of those that progressed, 33% (2/6) advanced to stage 2, while 67% (4/6) progressed to stage 3 US. Mean CS times were: between CS was 13 months (median: 8); across all CS was 20 months (median: 16.6); between stricture diagnosis to pro- gression was 29 months (median: 16); between stricture diagnosis and regression was 12 months (median: 9). CONCLUSIONS: Some early stage strictures will show regression over time and many will remain stable suggesting surveil- lance may be an option for some patients. The staging system provides a graded basis for evaluating progression of early stage strictures. Source of Funding: Institute of Bladder and Prostate Research MP13-16 A TGF-b1 BASED RAT MODEL FOR URETHRAL STRICTURE Premsant Sangkum*, Ahmet Gokce, Ronny Tan, Sree Harsha Mandava, Mostafa Bouljihad, Hogyoung Kim, George Lasker, Zakaria Abd Elmageed, Aaron Boonjindasup, Suresh Sikka, Asim Abdel-Mageed, Wayne Hellstrom, New Orleans, LA INTRODUCTION AND OBJECTIVES: TGF-b1 is a profibrotic agent used to create Peyronie’s disease in animal models. To date, there is no standardized animal model for the study of urethral stricture disease. Electrocoagulation or electro-resection via pediatric cysto- scope has been used to induce urethral stricture formation in larger animals such as rabbits and pigs1-3. This method is technically difficult in rats due to their small size and the lack of delicate instrumentation. The use of TGF- b1 injection to induce reproducible urethral stricture disease in the rat model has not been previously investigated.This is a proof of concept study using TGF- b1 injection to induce urethral strictures in a rat model. METHODS: Male Sprague-Dawley rats (250-300 g) were anesthetized with 100/10 ml/kg ketamine/xylazine intraperitoneally. Using a 5 mm peno-scrotal incision, the rat urethra was exposed under magnification. In the experimental group, 25 micrograms of TGF- b1 was injected into both sides of the urethral wall at the penoscrotal junction. Normal saline infiltration was used in the sham group. Routine skin closure was performed in both groups. Rats were sacrificed at 2 and 4 weeks post injection and the urethral specimens were stained with Hematoxylin and Eosin (H&E), Masson’s trichrome and other immunohistochemistry evaluations were performed. Vol. 191, No. 4S, Supplement, Saturday, May 17, 2014 THE JOURNAL OF UROLOGY â e181