Abstracts from the Mid-Atlantic Section of the AUA 2020

MA AUA 2020 Abstracts To Clamp or Not to Clamp: Foregoing Hilar Clamping During Partial Nephrectomy Does Not Change Renal Outcomes S. Gurram 1 ; N. Freidberg 1,2 ; W. Li 1 ; M. Ahdoot 1 ; S. Telfer 1 ; N. Yerram 1 ; H. Chalfin 1 ; W.M. Linehan 1 ; M. Ball 1 1 National Cancer Institute, National Institutes of Health, Bethesda, MD, USA; 2 George Washington University, Washington, DC, USA Introduction: Early data has shown that vascular clamping and increased ischemia time during partial nephrectomy (PN) has led to higher rates of both acute and chronic kidney disease. However, more recent studies have challenged this notion. Most contemporary series, however, do not assess if there is a benefit from forgoing vascular clamping altogether and avoiding ischemia. The purpose of our study is to assess if use of ischemia or type of ischemia utilized is associated with long- term renal outcomes. Materials & Methods: A retrospective review of a prospectively maintained database of patients undergoing renal surgery from 2008 to 2019 was performed. Patients who underwent PN were placed into four cohorts based on the intraoperative ischemia strategy used: No ischemia, cold ischemia, warm ischemia time (WIT) ≤ 30 min, and WIT > 30 min. A majority of these patients had known or suspected hereditary kidney cancer syndromes and frequently presented with multiple tumors. Functional renal outcomes and adverse outcomes were compared amongst the cohorts. Results: A total of 794 PN were included in this study. 504 PN were performed without ischemia, 81 with cold ischemia, 151 with WIT ≤ 30 min, and 58 with WIT > 30 min. Significant differences were noted in median number of tumors removed and preoperative creatinine. On multivariate analysis, 12-month post-operative creatinine changes were not significantly different amongst the four cohorts when controlling for the number of tumors removed, EBL, or preoperative creatinine. Conclusions: To our knowledge, this is the largest series to date assessing off-clamp PN. This study supports that the use of ischemia or the type of ischemia utilized is not associated with long-term changes in renal function and that ischemia time likely has a smaller role than originally presumed. The use of ischemia during PN is not detrimental towards long-term renal function, especially amongst patients with multifocal renal tumors. Urinary Biomarker Panel to Differentiate Benign Renal Masses fromAggressive and Indolent Renal Cell Carcinoma M. Biles; J. Cheaib; W. Obeid; C. Parikh; R. Becker; R. Alam; M. Metcalf; H. Patel; P. Pierorazio Johns Hopkins Hospital, Baltimore, MD, USA Introduction: Renal masses comprise a disease spectrum with varied natural history. Radiographic evaluation persists as the strongest predictor of tumor malignancy. The pathogenesis of clear cell renal cell carcinoma (ccRCC) includes increased angiogenesis and immunogenicity. Our aimwas to evaluate urine based markers targeting these pathways to differentiate between aggressive ccRCC, indolent ccRCC and benign renal tumors. Materials & Methods: The IRB-approved renal mass registry (2005-2020) was reviewed for patients with frozen urine samples who underwent renal mass surgery. Tumors were defined as benign (oncocytoma, anygiomyolipoma, or renal cyst), indolent ccRCC (low grade I-II and stage I-II), and aggressive ccRCC (high grade III-IV or stage III-IV). Benign and indolent ccRCC were classified as non- aggressive for analysis. Urine samples were analyzed for albumin and creatinine (Randox Daytona chemistry analyzer; Randox Laboratories Ltd, UK), to assess renal function and normalize data, and for markers of inflammation and angiogenesis with the MesoScale Discovery Platform (MesoScale Diagnostics, LLC, US), using patterned arrays with electrochemiluminescence detection. Values below the limit of detection (LOD) were imputed as half LOD. Mean and median biomarker levels were obtained for each group, and comparative ratios were generated across groups. Results: Urine samples from 76 patients were identified, including 20 benign, 22 indolent, and 34 aggressive tumors. Microalbumin was decreased and IL-1B levels were increased, strongly differentiating aggressive ccRCC from non-aggressive tumors. bFGF and VEGF levels were lower in ccRCC than benign tumors. Other discriminatory markers include IL-10, IL-9, and PIGF (FIGURE). Conclusions: Preliminary data suggests a urine-based panel of angiogenic and inflammatory markers can discriminate among benign renal tumors, indolent ccRCC and aggressive ccRCC. Potential biomarkers include microalbumin, IL-1B, bFGF, IL-10, IL-9, and VEGF, although further exploration is required. PDA-06 PDA-05 7 Podium Session A