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Introduction and Objectives: It is well known that adipose tissue plays a key role in the metabolic syndrome. We investigated whether visceral fat (VFA) and or subcutaneous fat (SQF) levels are associated with the tumor phenotype of small renal masses. Additionally, we sought to investigate the relationship between VFA and baseline renal function as measured by glomerular filtration rate. Materials and Methods: From 2002 through 2011, 144 patients undergoing minimally invasive partial nephrectomy were retrospectively reviewed by a radiologist for VFA and SQF fat measurements, using standard software. A third parameter, visceral adipose tissue percent (VAT%), was also calculated using the formula: (VAT%=[VFA/VFA+SQF]×100%). We used tertiles of VFA and SQF content to compare demographic and clinical characteristics. We also looked at VFA as a continuous variable. Associations between covariables were analyzed using multivariate logistic regression analysis and odds ratios with 95% confidence intervals. Results: Eighty-one patients had renal-cell carcinoma (RCC) and 30 patients had non-RCC pathology. On multivariate analysis, increasing BMI ( p=0.023), VFA ( p=0.048), VAT% ( p=0.028), and Charlson comorbidity score ( p=0.047) were significantly associated with worse preoperative Modification of Diet in Renal Disease (MDRD). In a subset multivariate analysis of the 81 patients with RCC, increasing VFA was statistically associated with worsening Fuhrman grade ( p=0.017). Conclusions: VFA may be linked to the pathophysiology of renal function in patients evaluated for renal masses. Additionally, VFA may be associated with worsening tumor grades in patients with small-volume RCC. Interestingly, SQF did not play such a role. This small study proposes an interesting physiologic link between VFA and the biology of both kidney function and tumor histology. Larger studies are needed to corroborate our findings. [ABSTRACT FROM AUTHOR]

OBJECTIVES To present the glomerular filtration rate (GFR) and oncological outcomes in a series of patients with cT1a renal cortical tumours treated with radiofrequency ablation (RFA), a non-ischaemic minimally invasive ablative method, as nephron-sparing surgery gives excellent oncological outcomes and preserves renal function. PATIENTS AND METHODS Healthy (American Society of Anesthesiologists, ASA, I and II) patients with cT1a renal masses were identified, and clinical and radiographic data were reviewed to assess indications, complications, radiological evidence of disease recurrence, and renal function. Changes in GFR were calculated. Radiological recurrence was defined as any new enhancement (>10 Hounsfield units) after absence of enhancement on initial 6-week computed tomography. RESULTS Four patients were ASA I and 59 were ASA II; the median (range) age was 58 (20–84.6) years and the lesion diameter 2.1 (1–4.0) cm. Preoperative needle biopsy was diagnostic in 89% of patients, including 75% diagnostic of renal cell carcinoma (RCC). At a median (range) follow-up of 34 (1.0–80) months the renal preservation rate was 97%. One patient had a nephrectomy for biopsy-confirmed recurrence of RCC at 55 months; a second had a nephrectomy at 24 months for suspected radiographic recurrence, but had no evidence of disease on final pathology. A fifth (20%) of the patients had chronic kidney disease at the time of diagnosis. The median GFR before and after RFA was 76.3 and 74.3 mL/min/m2 (difference 2.0 mL/min/m2). CONCLUSION RFA might be a reasonable treatment choice for the healthy patient, with appropriate informed consent. Intermediate results suggest excellent oncological outcomes and preservation of renal function. [ABSTRACT FROM AUTHOR]

Purpose: Radio frequency ablation is an emerging nephron sparing treatment option in select patients with small renal tumors. Some have questioned the completeness of cell death and the reliability of axial imaging for radio frequency ablation followup. We present results in patients with no evidence of radiographic active disease who underwent biopsy more than 1 year following ablation. Materials and Methods: Patients who had no clinical evidence of disease, defined as absent lesion growth and contrast enhancement on computerized tomography, 1 year or more following radio frequency ablation underwent percutaneous renal biopsy to evaluate cell viability in the ablative zone. A total of 19 patients (20 lesions) were included in the study. Histological comparison of pre-ablation and post-ablation specimens was performed using hematoxylin and eosin staining. Results: Pre-ablation biopsies confirmed that 17 of 20 tumors were renal cell carcinoma, while the remaining 3 were oncocytoma. Following ablation at a mean followup of 26.9 months (range 13.1 to 58.0) all 20 lesions were stable in size without evidence of contrast enhancement on computerized tomography. At repeat biopsy all histology specimens showed unequivocal tumor eradication with no evidence of cellular viability. Histological changes beyond 1 year demonstrated coagulative necrosis, hyalinization, inflammatory cell infiltration and residual ghost cells. Conclusions: Pathological examination of radiographically negative lesions biopsied more than 1 year following radio frequency ablation confirmed no evidence of disease in all specimens. Therefore, axial imaging can reliably monitor treatment efficacy in the long term. Chronic changes after radio frequency ablation demonstrate coagulative necrosis and nonviable cells. This suggests an evolution of pathological changes that renders early post-ablative biopsy unreliable. [Copyright &y& Elsevier]

Purpose: We examined the effect of radical nephrectomy, partial nephrectomy and radio frequency ablation on renal function in patients with stage T1a renal masses. Materials and Methods: A total of 242 consecutive patients from July 1995 to March 2005 undergoing primary treatment for unilateral renal masses smaller than 4 cm and a normal contralateral kidney were identified. Renal function was calculated using the modified Modification of Diet in Renal Disease equation. The rate of decrease in the glomerular filtration rate below 60 ml per minute 1.73 m2 was compared among the 3 treatment modalities. Results: A total of 86, 85 and 71 patients were treated with radio frequency ablation, partial nephrectomy and radical nephrectomy, respectively. Preoperatively stage 3 chronic kidney disease (glomerular filtration rate less than 60 ml per minute per 1.73 m2) was identified in 65 patients (26.7%), including 26.7%, 27.1% and 26.8% who underwent radio frequency ablation, partial nephrectomy and radical nephrectomy, respectively. Following intervention the 3-year freedom from a glomerular filtration rate decrease of below 60 ml per minute per 1.73 m2 for radio frequency ablation, partial nephrectomy and radical nephrectomy was 95.2%, 70.7% and 39.9%, respectively (p <0.001). Multivariate analysis showed that radical nephrectomy was an independent risk factor vs radio frequency ablation and partial nephrectomy for stage 3 chronic kidney disease (HR 34.3, 95% CI 4.28–275 and 10.9, 95% CI 1.36–88.7, respectively). Conclusions: Decreased renal function is prevalent in patients with small unilateral renal tumors even with a normal contralateral kidney. Ablative or extirpative nephron sparing techniques are effective for preserving renal function in these patients. [Copyright &y& Elsevier]

OBJECTIVE To compare the intermediate-term outcomes of patients with clinical T1a renal tumours who were treated with nephron-sparing surgery by partial nephrectomy (PN), the preferred approach for small (cT1a) renal tumours, or radiofrequency ablation (RFA), recently offered to selected patients as an alternative, less morbid technique. PATIENTS AND METHODS We identified patients with stage T1a renal masses who had ≥ 2 years of follow-up; those with bilateral synchronous or metachronous tumours, metastatic disease at presentation, or a family history of renal cell carcinoma were excluded. From July 1996 to January 2004 110 PNs were identified in our database; 37 patients who fulfilled the inclusion criteria had either open (30) or laparoscopic PN (seven) and 40 had either percutaneous (26) or laparoscopic (14) RFA. RESULTS The mean (range) follow-up for the RFA and PN groups was 30 (18–42) and 47 (24–93) months, respectively; the respective mean tumour size was 2.41 and 2.43 cm. There was one incomplete ablation and two local recurrences in the RFA group, and two recurrences in the PN group (one local and one in the contralateral kidney). There were no disease-specific deaths. The overall actuarial disease-free probability for the PN and RFA groups, respectively, was 95.8% and 93.4% ( P = 0.67). CONCLUSIONS This initial 3-year actuarial analysis showed that RFA for cT1a renal tumours has comparable oncological outcomes to PN; however, longer term data are still needed. [ABSTRACT FROM AUTHOR]

Purpose: Nicotinamide adenine dinucleotide diaphorase staining is arguably the standard for assessing tissue viability following radio frequency ablation, yet the accuracy of this test is questionable. Thus, it is imperative to examine the reliability of nicotinamide adenine dinucleotide to predict ablation success. To evaluate the observation that immediate nicotinamide adenine dinucleotide staining may not be clinically reliable, we compared results from immediate post-ablation biopsies of renal tumors to radiological and clinical followup. Materials and Methods: Laparoscopic radio frequency ablation was performed in 9 patients and 10 tumors using a temperature modulated radio frequency system. Cold cup biopsies were taken immediately following ablation, and processed for nicotinamide adenine dinucleotide and hematoxylin and eosin staining. Patients were then followed using contrast enhanced computerized tomography at regular intervals. Results: Median tumor size was 2.3 cm. Hematoxylin and eosin stain diagnosed 8 renal cell carcinomas and 2 angiomyolipomas. A quarter of the renal cell carcinomas and both angiomyolipomas stained positive for scattered nicotinamide adenine dinucleotide diaphorase activity immediately after RFA. Mean followup for the nicotinamide adenine dinucleotide positive tumors was 28.5 months (range 24 to 30) and for the nicotinamide adenine dinucleotide negative tumors was 25 months (range 18 to 30). There was no evidence of local tumor recurrence in any patient. Conclusions: Four lesions had nicotinamide adenine dinucleotide diaphorase activity on post-ablation biopsy suggesting retained viable tissue, yet there has been no recurrence during an average 2-year followup. While negative nicotinamide adenine dinucleotide staining is consistent with nonviability, these results suggest that false-positive staining can occur immediately following RFA, making the predictive value of positive nicotinamide adenine dinucleotide diaphorase staining unclear. [Copyright &y& Elsevier]

Introduction: Recent studies have proposed that nearby fat deposits may have metabolic influence on kidney cancer pathobiology. Both fat quantity and quality may play unique roles in this complex relationship. As such, we investigated whether perinephric fat surface area (PFA), a quantitative measure of fat, or Mayo Adhesive Probability (MAP) score, a qualitative measure, were predictive of malignant pathology or Fuhrman grade in small renal masses.Methods: A total of 317 patients undergoing minimally invasive partial nephrectomy between 2010 and 2016 for renal masses were retrospectively reviewed. Preoperative abdominal CT and MRI scans were measured for PFA and MAP scores. Multiple binary logistic regression models were created to identify predictive factors of malignant disease and Fuhrman grade.Results: A total of 253 patients had malignant masses, while 64 had benign masses. A total of 189 of the malignant masses were T1a, while 64 were designated T1b. A total of 221 patients with malignant masses had reported Fuhrman grades. Of these 211 patients, 143 (64.7%) had low-grade and 78 (35.3%) had high-grade disease. Mean PFA was 18.0 ± 13.3 cm2, while mean MAP score was 2.6 ± 1.2. Binary logistic regression analysis yielded three variables in the best-fit model for predictors of malignant pathology: MAP score (OR = 1.374, 95% CI: 1.007-1.873, P = 0.045), male sex (OR = 2.058, 95% CI: 1.004-4.218, P = 0.049), and BMI (OR = 1.064, 95% CI: 0.998-1.135, P = 0.059). Neither MAP nor PFA was predictive of Fuhrman grade.Conclusions: MAP score, a measure of perinephric fat quality, but not PFA, a qualitative measure of fat quantity, was predictive of malignant pathology, raising the question whether fat quality rather than quantity may be involved in the pathophysiology of RCC in a large and diverse patient population. Understanding the increasing burden of obesity, further studies are needed to elaborate on these findings and to discern the exact relationship between perinephric fat deposits and renal tumorigenesis. [ABSTRACT FROM AUTHOR]