696 THE EFFECT OF FENOLDOPAM ON RENAL FUNCTION IN SOLITARY KIDNEY PARTIAL NEPHRECTOMY

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THE JOURNAL OF UROLOGY姞

Vol. 185, No. 4S, Supplement, Monday, May 16, 2011

decade, assess the accuracy of renal biopsy for predicting tumor histologic subtype and nuclear grade, and illustrate the role of renal biopsy in surgical versus non-surgical management. METHODS: A retrospective chart review was performed including patients in the Southern California Kaiser Permanente Medical Region that underwent either CT or ultrasound guided core percutaneous renal biopsy of a solid renal mass from January 2005 to December 2009. Patients were stratified by size of renal mass, comparing SRMs (less than or equal to 4 cm) to larger renal tumors. Initial biopsy results including tumor histology and nuclear grade were evaluated and related to postoperative pathology specimens when surgery was performed. RESULTS: The study included 126 patients (129 renal units with 132 biopsies). Sixty-three patients (50%) ultimately underwent surgery (23 partial and 40 radical nephrectomies). Patients who did not have surgical intervention tended to be older, average 68 years old versus 61 years old and have larger tumors 5.5 cm versus 4.0 cm. The overall sensitivity for detecting cancer (verified by final pathology) in our series was 75.4% with 100% specificity. The positive predictive value for patients who underwent surgery was 100% and negative predictive value 11.7%. When evaluating factors associated with accuracy of predicting cancer, larger tumor size has an odds ratio of 1.21 (p⫽ 0.10) and increasing number of biopsy samples has an odds ratio of 1.57 (p ⫽ 0.17). CONCLUSIONS: Percutaneous renal needle biopsy in the modern era has respectable sensitivity, excellent specificity and good concordance with final pathology. This modality can assist in clinical decision-making for renal masses, particularly for SRMs, as treatment options are expanding. Description of biopsies MASS ⬍/ ⫽ 4 cm Number of biopsies (%) RENAL BIOPSIES (n⫽132)

MASS ⬎ 4 cm Number of biopsies (%)

59 (44.7%)

73 (55.3%)

6 (10.2%)

1 (1.4%)

Benign biopsy

21 (35.6%)

17 (23.3%)

Cancer in biospy

32 (54.2%)

55 (75.3%)

Non diagnostic biopsy

NON DIAGNOSTIC OR BENIGN BIOPSY Mass excised with surgery Cancer in nephrectomy specimen

Cancer in nephrectomy specimen Concordance to renal cancer subtype Concordance to Fuhrman Grade

Source of Funding: None

697 A CLASSIFICATION TREE FOR THE PREDICTION OF BENIGN DISEASE IN THE MANAGEMENT OF RENAL MASSES: AIDING THE CLINICIAN’S THOUGHT PROCESS Ricardo A. Rendon*, Ross J. Mason, Susan Kirkland, Joseph G. Lawen, Mohamed Abdolell, Halifax, Canada

9/27 (33.3%)

8/18 (44.4%)

8 (88.9%)

7 (87.5%)

15/32 (46.9%)

31/55 (56.4%)

15 (100.0%)

31 (100.0%)

11/11 (100.0%)

16/18 (88.9%)

2/4 (50.0%)

5/9 (55.6%)

CANCER IN BIOPSY Mass excised with surgery

METHODS: 90 patients with solitary kidneys undergoing elective partial nephrectomy were randomized to fenoldopam or placebo in a double-blind protocol. Patients assigned to fenoldopam received an infusion rate of 0.1 ␮g/kg/min started after general anesthesia induction and continued for 24 hours. Placebo patients were given comparable volumes of saline. The primary outcome was the increase in GFR from preoperative value to the third postoperative day, as determined by a Wilcoxon rank-sum test. Repeated-measures analysis of variance was used to assess overall and time-specific effects of fenoldopam on log-transformed SCr, after adjusting for baseline values. RESULTS: Among 90 enrolled patients, 13 met intra-operative exclusion criterion; leaving 77 patients to be analyzed (fenoldopam: n⫽43). Baseline and intraoperative covariables were well-balanced in the randomized groups. The mean ⫾ SD of ischemia time was 22⫾8 and 23⫾7 minutes for fenoldopam vs. placebo patients; the fraction of renal resection was 23⫾14 and 25⫾12% for the two groups. There was no significant effect of fenoldopam (vs. placebo) on the percent change in GFR from baseline to POD 3, with median change [Q1, Q3] of -28% [-60%, 4%] vs. -39% [-56%, -23%, P⫽0.25). The median percent decrease in GFR was an estimated 9% less (95% CI: 25% less, 7% more) for the fenoldopam group than for placebo group (Fig 1a, P⫽0.25). Postoperative SCr in the two groups changed at comparable rates (P ⫽ 0.72, interaction) after adjusting for baseline creatinine (Fig 1b). The overall ratio of geometric means of post-op SCr values (including immediate post-op through POD 4) was an estimated 0.96 (95% CI: 0.78, 1.19) for fenoldopam vs. placebo (P⫽0.64). CONCLUSIONS: Fenoldopam administration did not preserve renal function in the clinical setting of renal ischemia during solitary partial nephrectomy as evidenced by GFR or SCr comparisons.

Source of Funding: Kaiser Permanente Southern California Regional Research Committee

696 THE EFFECT OF FENOLDOPAM ON RENAL FUNCTION IN SOLITARY KIDNEY PARTIAL NEPHRECTOMY Amr Fergany*, Jerome O’Hara, Steven Campbell, Kristina Kaple, Angela Bonilla, Cleveland, OH INTRODUCTION AND OBJECTIVES: Fenoldopam is a shortacting dopamine A-1 receptor agonist that decreases systemic vascular resistance while simultaneously increasing renal blood flow. A recent meta-analysis of fenoldopam trials reported an apparent decrease in the development of acute tubular necrosis, requirement for dialysis, and overall patient mortality. We tested the hypothesis that fenoldopam administration ameliorates ischemic injury by preserving glomerular filtration rate (GFR) and serum creatinine (SCr) postoperatively in solitary partial nephrectomy.

INTRODUCTION AND OBJECTIVES: Most new renal masses are now diagnosed incidentally while still small in size. Most of these small renal masses (SRM) are treated with partial nephrectomy, a procedure with a significant amount of complications. Multiple series have reported a high proportion (up to 46%) of benign histology after surgical resection of these small renal masses. There is a clear need for accurate prediction of benign disease. Multiple preoperative factors such as sex, age, tumor size and location have been implicated in the prediction of benign histology. We aimed to apply classification tree algorithms to discriminate between benign and malignant histology when SRMs are being evaluated preoperatively. METHODS: A classification tree was developed based on a cohort of 385 patients who underwent surgical management for presumed renal cell carcinoma ⬍ 5cm in largest diameter at our institution between July 1st 2001 and June 30th 2010. Age, sex, tumor size (largest bi-dimensional diameter in cm), tumor location (central vs. peripheral), degree of endophytic component (1-100%) and tumor axis location (according to the three renal axes) were used to develop the model. RESULTS: The overall incidence of benign disease was 11.4%. The classification tree partitioned the subjects into seven disjoint sets differing in risk of benign histology based on a minimum of one and a maximum of four predictors; symptoms at diagnosis, % endophytic, tumor size, and patient age. As an example in one branch of the tree, patients who had tumors that were less than 5.7cc (n⫽84) and less than 45% endophytic (n⫽19) had a 52.6% chance of having a benign tumor. Conversely, 100% of patients with tumors larger than 5.7cc (311), who were symptomatic at diagnosis (207), and who’s tumors were greater than 85% endophytic (40) had a malignant renal mass on final histology. The cross-validated estimate accuracy of the model is 87.8% with a 95% CI (85.8, 92.7).