Abstracts from the New England Section of the AUA 2020: A Virtual Experience

NE AUA 2020 Abstracts 5 Surgical Site Infection in Robot-assisted Radical Cystectomy vs. Open Radical Cystectomy Katelyn K. Johnson, MD , Kevan Ip, BA, Sara Rubino, BA, Cynthia Leung, MD, Cayce B. Nawaf, MD, Thomas V. Martin, MD, David G. Hesse, MD Yale University, New Haven, CT Introduction: Radical cystectomy has a high incidence of complications due to the complex nature of the procedure. Little is known about the comparative risk of surgical site infection associated with robot-assisted radical cystectomy (RARC) vs. open radical cystectomy (ORC). Patients at our institution were analyzed to assess risk of developing SSI based on surgical approach. Materials &Methods: All patients undergoing radical cystectomywith pelvic lymph node dissection for urothelial carcinoma of the bladder at a single institution from 2007-2017 were retrospectively reviewed. Data included age, sex, body mass index (BMI), Charlson Age-Adjusted Comorbidity Index (CCI), history of diabetes, surgical approach (RARC or ORC), urinary diversion type, length of operation, estimated blood loss (EBL), surgical site infection (SSI), and length of hospital stay (LOS). SSIs were defined using criteria outlined by the National Surgical Quality Improvement Program (NSQIP) that occurred at any point postoperatively. There were no exclusion criteria in terms of clinical or pathologic stage. Simple and multiple logistic regression models were fitted to the data to assess the role of perioperative factors on risk of surgical site infection. Independent variables that are correlated were excluded during variable selection in multiple regression analysis in order to satisfy the assumption of non-multicollinearity. Differences between the RARC and ORC patient cohorts were analyzed using Student’s t-test or Wilcoxon rank sum test for continuous variables, and Pearson’s Chi-squared test for categorical variables. Statistically significant differences were defined as p < 0.05. 6 Metabolomic Evaluation of Renal Cell Carcinoma and Fat-Poor Angiomyolipoma with Magnetic Resonance Spectroscopy Melissa Huynh, MD, Andrew Gusev, BA , Francesco Palmas, PhD, Lindsey Vandergrift, BA, Chin-Lee Wu, MD, Leo Cheng, PhD, Adam Feldman, MD, MPH Massachusetts General Hospital, Boston, MA Introduction: Renal cell carcinoma (RCC) is ametabolic disease, with the various subtypes exhibiting aberrations in different metabolic pathways. Metabolomics may offer greater sensitivity for revealing disease biology than evaluation of tissue morphology. In this study, we investigate the metabolomic profile of RCC using high resolution magic angle spinning (HRMAS) magnetic resonance spectroscopy (MRS). Materials &Methods: Tissue samples were obtained from radical or partial nephrectomy specimens that were fresh frozen & stored at -80ºC. Tissue HRMAS MRS was performed by a BrukerAVANCE spectrometer. Metabolomic profiles of RCC & adjacent benign renal tissue were compared, and false discovery rates (FDR) were used to account for multiple testing. Regions of interest (ROI) with FDR < 0.05 were selected as potential predictors of malignancy. The Wilcoxon rank sum test was used to compare median MRS relative intensities for the candidate predictors. Logistic regression was used to determine odds ratios for risk of malignancy based on abundance of each metabolite. Results: There were 38 RCC (16 clear cell, 11 papillary, 11 chromophobe) & 13 adjacent normal tissue specimens (matched pairs). Metabolic predictors of malignancy based on FDR include histidine, phenylalanine, phosphocholine, serine, phosphocreatine, creatine, glycerophosphocholine, valine, glycine, myo-inositol, scylla-inositol, taurine, glutamine, spermine, acetoacetate & lactate. Higher levels of spermine, histidine & phenylalanine at 3.15-3.13 ppmwere associated with a decreased risk of RCC (OR 4x10 -5 , 95% CI 7.42x10 -8 , 0.02), while 2.84-2.82 ppm increased the risk of malignant pathology (OR 7158.67, 95% CI 6.3, 8.3x10 6 ), and the specific metabolites characterizing this region remain to be identified. Tumor stage did not appear to affect the metabolomics of malignant tumors, suggesting that metabolites are more dependent on histologic subtype. Conclusions: HRMAS-MRS identified many metabolites that may predict RCC. We demonstrated that those in the 3.14-3.13 ppm ROI were present in lower levels in RCC, while higher levels of metabolites in the 2.84-2.82 ppm ROI substantially increased the risk of RCC. Introduction: Fat-poor angiomyolipoma (AML) can be difficult to differentiate from renal cellcarcinoma(RCC)radiographicallyandmay lead tobiopsyorunnecessary intervention. In vivo platforms with the ability to identify tumor histology based on metabolic profiles may avoid unnecessary procedures & their complications. The metabolomics ofAMLhave not been characterized, & research into this area may provide targetable molecules for large AMLs. In this study, we investigate the metabolomic profile of AMLs compared to clear cell RCC (ccRCC) using high resolution magic angle spinning (HRMAS) magnetic resonance spectroscopy (MRS). Materials &Methods: Tissue samples were obtained from radical or partial nephrectomy specimens that were fresh frozen & stored at -80ºC. Tissue HRMAS MRS was performed by a BrukerAVANCE spectrometer. Metabolomic profiles of RCC & adjacent benign renal tissue were compared, and false discovery rates (FDR) accounted for multiple testing. Regions of interest (ROI) with FDR < 0.05 were considered potential predictors of ccRCC rather thanAML. The Wilcoxon rank sum test was used to compare median MRS relative intensities for candidate predictors. Logistic regression was used to determine odds ratios for risk of malignancy based on abundance of each metabolite. Results: There were 16 ccRCC samples & 7 AML specimens. Candidate predictors of malignancy rather than AML based on FDR p-values include histidine, phenylalanine, phosphocholine, serine, alanine, glutamate, glutathione, glycerophosphocholine, & glutamine. While an abundance of these metabolites is associated with higher risk of malignancy, the odds ratio was particularly high in the 3.5-3.49 ppm spectral region (OR 2.99x10 6 , 95% CI 3.27, 2.73x10 12 , p =0.033) in ccRCC samples. Conclusions: HRMAS MRS identified metabolites that may help differentiate fat-poor AMLfrom ccRCC. In particular, metabolites in the 3.5-3.49 ppm spectral region increased the risk of harboring RCC. Our findings may contribute to future in vivo studies to help identify which patients require intervention for malignancy & which may be observed for benign AML without requiring biopsy ParastomalHerniaDevelopmentafterCystectomyandIlealConduitforBladderCancer: Results from the Dartmouth Ileal Conduit Enhancement (DICE) Project Michael E. Rezaee, MD, MPH , Jenaya L. Goldway, MD, Briana Goddard, BA, William Bihrle, III, MD, Alexei Viazmenski, MD, Matthew Z. Wilson, MD, MSc, John D. Seigne, MBBCh Dartmouth-Hitchcock Medical Center, Lebanon, NH. Introduction: Limited information exists regarding parastomal hernia development in bladder cancer patients. The purpose of this investigation was to describe the natural history of parastomal hernias and identify risk factors for hernia development in patients who undergo cystectomy with ileal conduit urinary diversion. Materials&Methods: Aretrospectivecohortstudywasperformedofbladdercancerpatients who underwent cystectomy with ileal conduit urinary diversion between January 1st 2009 and July 31st 2018 at Dartmouth-HitchcockMedical Center. The primary outcome of interest was the presence of a parastomal hernia as evident on post-operative cross-sectional imaging obtained for disease surveillance. Results: A total of 107 patients were included with a mean age of 70.9 years and 29.9% being female. Parastomal hernias were identified in 68.2% of bladder cancer patients who underwent cystectomy with ileal conduit urinary diversion. 40% of patients with a parastomal hernia reported symptoms related to their hernia, while 12.5% underwent operative repair. After multivariate adjustment, patients with a post-op BMI > 30 kg/m 2 (Odds Ratio [OR]: 21.8, 95% CI: 1.6-305.2) or stage III or IV bladder cancer (OR: 18, 95% CI: 2.1-157.5), had significantly greater odds of parastomal hernia development. Fifty percent of parastomal hernias were identified 1.3 years from surgery, while 75%were identified by two years after cystectomy. Conclusions: Parastomal hernias developed in over two-thirds of bladder cancer patients and occurred rapidly following cystectomy and ileal conduit urinary diversion. Greater post-operative BMI and bladder cancer stage were identified as significant risk factors for parastomalherniadevelopment.Significantopportunityexiststoreducemorbidityassociated with parastomal hernias in this population. 4* Scientific Session I: Oncology I 3 Results: We identified a total of 232 patients (73 robotic, 159 open) who underwent radical cystectomy. SSI was significantly lower in RARC vs. ORC (14% vs. 29%, p = 0.01). RARC patients had lower EBL than ORC patients (mean: 500 vs. 850 mL, p < 0.0001), higher CCI (mean: 6.2 vs. 5.3, p < 0.05), and longer operative times (mean: 550 vs. 360 minutes, p < 0.0001). There was no significant difference in BMI (p = 0.93), diabetes (p = 0.58), urinary diversion type (continent vs. non-continent, p = 0.71), or LOS (p = 0.34) between surgical approaches. On simple univariate logistic regression, surgical approach (RARC vs. ORC, OR=0.40, 95% CI: 0.19-0.84, p = 0.016), EBL (OR = 1.0008, 95% CI: 1.0002-1.0014, p = 0.007), BMI (OR = 1.06, 95% CI: 1.002-1.125, p = 0.043), and LOS (OR = 1.05, 95% CI: 1.006-1.102, p = 0.026) were found to have significant correlation with risk of SSI. Diabetes, CCI, operative time, and urinary diversion method had no significant correlation with risk of SSI. Multivariate logistic regression including surgical approach (OR = 0.34, p = 0.008), LOS (OR = 1.06, p = 0.017), and BMI (OR = 1.07, p = 0.035) show that these variables have a significant relationship with SSI risk. Conclusions: Patients who underwent RARC had a significantly lower SSI rate compared to those who underwent ORC. RARC patients experienced significantly lower EBL. Logistic regression analysis shows a strong relationship between surgical approach and SSI risk, suggesting a 60% reduction in SSI risk associated with RARC, as well as a strong relationship between EBL and SSI risk. Reduced risk of SSI in RARC may be mediated by lower EBL in RARC vs. ORC. *Max K. Willscher Award Eligible