Nicholas Kavoussi

Diagnostic Accuracy of Multiparametric Magnetic Resonance Imaging to Identify Clear Cell Renal Cell Carcinoma in cT1a Renal Masses

Purpose: The detection of small renal masses is increasing with the use of cross‐sectional imaging, although many incidental lesions have negligible metastatic potential. Among malignant masses clear cell renal cell carcinoma is the most prevalent and aggressive subtype. A method to identify such histology would aid in risk stratification. Our goal was to evaluate a likelihood scale for multiparametric magnetic resonance imaging in the diagnosis of clear cell histology. Materials and Methods: We retrospectively reviewed the records of patients with cT1a masses who underwent magnetic resonance imaging and partial or radical nephrectomy from December 2011 to July 2015. Seven radiologists with different levels of experience who were blinded to final pathology findings independently reviewed studies based on a predefined algorithm. They applied a clear cell likelihood score, including 1—definitely not, 2—probably not, 3—equivocal, 4—probably and 5—definitely. Binary classification was used to determine the accuracy of clear cell vs all other histologies. Interobserver agreement was calculated with the weighted &kgr; statistic. Results: A total of 110 patients with 121 masses were identified. Mean tumor size was 2.4 cm and 50% of the lesions were clear cell. Defining clear cell as scores of 4 or greater demonstrated 78% sensitivity and 80% specificity while scores of 3 or greater showed 95% sensitivity and 58% specificity. Interobserver agreement was moderate to good with a mean &kgr; of 0.53. Conclusions: A clear cell likelihood score used with magnetic resonance imaging can reasonably identify clear cell histology in small renal masses and may decrease the number of diagnostic renal mass biopsies. Standardization of imaging protocols and reporting criteria is needed to improve interobserver reliability.

Low Serum Testosterone Level Predisposes to Artificial Urinary Sphincter Cuff Erosion

OBJECTIVE To examine the association between decreased serum testosterone levels and artificial urinary sphincter (AUS) cuff erosion. MATERIALS AND METHODS We evaluated serum testosterone levels in 53 consecutive patients. Low testosterone was defined as <280 ng/dL and found in 30/53 patients (56.6%). Chi-square and Student t tests, Kaplan-Meier analysis, binary logistic regression, and Cox regression analysis were used to determine statistical significance. RESULTS Nearly all men with AUS cuff erosions had low serum testosterone (18/20, 90.0%) compared to those without erosions (12/33, 36.4%, P < .001). Mean time to erosion was 1.70 years (0.83-6.86); mean follow-up was 2.76 years (0.34-7.92). Low testosterone had a hazard ratio of 7.15 for erosion in a Cox regression analysis (95% confidence interval 1.64-31.17, P = .009) and Kaplan-Meier analysis demonstrated decreased erosion-free follow-up (log-rank P = .002). Low testosterone was the sole independent risk factor for erosion in a multivariable model including coronary artery disease and radiation (odds ratio 15.78; 95% confidence interval 2.77-89.92, P = .002). Notably, history of prior AUS, radiation, androgen ablation therapy, or concomitant penile implant did not confound risk of cuff erosion in men with low testosterone levels. CONCLUSION Men with low testosterone levels are at a significantly higher risk to experience AUS cuff erosion. Appropriate counseling before AUS implantation is warranted and it is unclear whether testosterone resupplementation will mitigate this risk.

Diagnostic performance and interreader agreement of a standardized MR imaging approach in the prediction of small renal mass histology

Purpose To assess the diagnostic performance and interreader agreement of a standardized diagnostic algorithm in determining the histologic type of small (≤4 cm) renal masses (SRMs) with multiparametric magnetic resonance (MR) imaging. Materials and Methods This single-center retrospective HIPAA-compliant institutional review board-approved study included 103 patients with 109 SRMs resected between December 2011 and July 2015. The requirement for informed consent was waived. Presurgical renal MR images were reviewed by seven radiologists with diverse experience. Eleven MR imaging features were assessed, and a standardized diagnostic algorithm was used to determine the most likely histologic diagnosis, which was compared with histopathology results after surgery. Interreader variability was tested with the Cohen κ statistic. Regression models using MR imaging features were used to predict the histopathologic diagnosis with 5% significance level. Results Clear cell renal cell carcinoma (RCC) and papillary RCC were diagnosed, with sensitivities of 85% (47 of 55) and 80% (20 of 25), respectively, and specificities of 76% (41 of 54) and 94% (79 of 84), respectively. Interreader agreement was moderate to substantial (clear cell RCC, κ = 0.58; papillary RCC, κ = 0.73). Signal intensity (SI) of the lesion on T2-weighted MR images and degree of contrast enhancement (CE) during the corticomedullary phase were independent predictors of clear cell RCC (SI odds ratio [OR]: 3.19; 95% confidence interval [CI]: 1.4, 7.1; P = .003; CE OR, 4.45; 95% CI: 1.8, 10.8; P < .001) and papillary RCC (CE OR, 0.053; 95% CI: 0.02, 0.2; P < .001), and both had substantial interreader agreement (SI, κ = 0.69; CE, κ = 0.71). Poorer performance was observed for chromophobe histology, oncocytomas, and minimal fat angiomyolipomas, (sensitivity range, 14%-67%; specificity range, 97%-99%), with fair to moderate interreader agreement (κ range = 0.23-0.43). Segmental enhancement inversion was an independent predictor of oncocytomas (OR, 16.21; 95% CI: 1.0, 275.4; P = .049), with moderate interreader agreement (κ = 0.49). Conclusion The proposed standardized MR imaging-based diagnostic algorithm had diagnostic accuracy of 81% (88 of 109) and 91% (99 of 109) in the diagnosis of clear cell RCC and papillary RCC, respectively, while achieving moderate to substantial interreader agreement among seven radiologists.

Ablative Therapies for the Treatment of Small Renal Masses: a Review of Different Modalities and Outcomes

The widespread utilization of abdominal imaging has led to an increase in incidentally detected small renal masses. Although partial nephrectomy is still considered the gold standard treatment for these masses, there are risks associated with surgical excision, potentially limiting treatment for older patients with multiple comorbidities. A variety of ablative techniques have developed over the past several decades, altering the management of small renal masses. It is likely that improvements in technology will only broaden the applications of ablative therapy. This article provides an update on the various ablative techniques and outcomes.

Penile Plication as Salvage Strategy for Refractory Peyronie's Disease Deformities

Introduction: We identified clinical and/or surgical factors contributing to failure of penile plication for Peyronies reconstruction and assessed outcomes of repeat plications. Methods: We conducted a retrospective review of patients who underwent penile plication between 2007 and 2016. Plication was performed after inducing an artificial erection intraoperatively using corrective longitudinal 2‐zero Ethibond™ sutures placed systematically in a uniform manner without circumcision. Penile length, and angle and direction of curvature were recorded, along with number and location of plication sutures and clinical outcome. Results: Of 340 patients undergoing penile plication during the study period 7 (2.1%) underwent repeat plication for insufficient straightening. Two additional patients underwent salvage plication after initial surgery performed elsewhere. Median time to revision was 6 months (range 3.4 to 27.4). The most common clinical features at reoperation were severe erectile dysfunction in 5 cases (71%), multiplanar curvature in 5 (71%) and severe curvature (60 degrees or greater) in 3 (43%). Most revisions involved a greater number of sutures during revision (mean 9) compared to initial plication (6), and in 4 cases (44%) sutures were placed on the proximal shaft. After revision all cases were noted to be functionally straight, with a mean postoperative curvature of 4 degrees (range 0 to 20) at a median followup of 27 months (3 to 76). Conclusions: Inadequate correction of Peyronies disease curvature by penile plication is rare but salvageable by a second plication procedure. Poor erectile response to intracavernous injection intraoperatively may mask the severity of the deformity, thus leading to inadequate numbers of corrective sutures.

MP22-11 PERFORMANCE OF MULTIPARAMETRIC MAGNETIC RESONANCE IMAGING TO IDENTIFY CLEAR CELL RENAL CELL CARCINOMA IN CT1A RENAL MASSES

patients referred for surgery while fear of biopsy-associated complications was the primary reason (58%) to decline RMB among those undergoing surveillance. Having an academic degree was associated with acceptance of a lower accuracy threshold (p1⁄40.03). Of the 59 participating urologists, 39% were reluctant to recommend RMB, primarily because of its inexorable non-diagnostic rate. CONCLUSIONS: Most patients and urologists would favor a RMB to facilitate their definitive treatment decision. Diagnostic accuracy of 95% was acceptable by the majority of study participants. The utility of RMB as part of the diagnostic algorithm for renal tumors should be discussed with patients, emphasizing its potential benefits and limitations.

V4-06 THE DEVELOPMENT OF A WEB-BASED VIDEO PLATFORM FOR TEACHING THE ROBOTIC SIMPLE PROSTATECTOMY

INTRODUCTION AND OBJECTIVES: PCNL is the first-line therapy for large and complex renal calculi. To perform PCNL safely and effectively, the most important step is the formation of a nephrostomy tract and tract dilatation. Furthermore, as fine a nephroscope as possible is required for micro PCNL. In this clinical study, renal puncture using 20 G all-seeing needle and 4.8 Fr micro PCNL were performed for large renal stone using a micro-optic disposable scope. METHODS: The f0.65 mm scope with the High Definition Image Guide (HDIG) system reported in previous WCE held in Taiwan (2014) was adopted. The scope consists of an integrated light lead and the micro fiber optic including a f0.5 mm precise object lens and optical glass fiber, where real-time HD images can be seen through the digital image processing device. The scope can be set inside a 20 G puncture needle or 4.8 Fr metal sheath which can simultaneously include the micro-optic scope, 0.018 inch guidewire and 200 mm laser fiber. These devices are developed as part of a collaborative research with Takei Medical & Optical Co. Ltd. (Tokyo, Japan) and Sumita Optical Glass Inc. (Saitama, Japan) funded by Utsukushima Next-Generation Medical Industry Agglomeration Project between 2012 and 2014. After evaluating safety, optical quality and operation performance in an animal study, the clinical study authorized by the ethical committee of Okayama University Hospital was carried out from June 2013. The procedures of micro PCNL are as follows; ultrasound-guided renal puncture using 20 G all-seeing needle, removal of the scope followed by insertion of 0.018 inch guidewire, dilatation by metal introducer, insertion of 4.8 Fr metal sheath into renal calyx, insertion of the HDIG scope into the sheath, complete fragmentation of calculi by Ho-YAG LASER without removal of the fragments. RESULTS: A 68-year old male with renal calculi 21 mm in diameter in left lower calyx once underwent the puncture and the micro PCNL. After the operation, spontaneous discharge of fragmented calculi through lower urinary tract was observed and abdominal X-ray on POD 21 showed no fragment in his left kidney. No adverse event was occurred except slight elevation of serum creatinine during only a week postoperatively. CONCLUSIONS: The micro-optic disposable scope with the HDIG system is extremely useful for safer puncture and finer PCNL. We are now planning to adopt it to percutaneous procedure for urothelial carcinoma in upper urinary tract.

Effect of Differing Parameters on Irreversible Electroporation in a Porcine Model

INTRODUCTION AND OBJECTIVE Irreversible electroporation (IRE) is a new ablative technology to treat small renal masses. We evaluated differed ablation settings on lesion size and temperature changes in a porcine model. MATERIALS AND METHODS After Institutional Animal Care and Use Committee approval, 36 laparoscopy-guided and 16 open ablations were performed on 13 domestic female pigs. Ablation parameters studied were voltage (1000 V/cm, 1500 V/cm, or 2000 V/cm), probe exposure (1.0 or 1.5 cm), and lesion size over time (survival) (0-, 7-, or 14 day). Temperature changes were monitored during open ablations with differed settings. Gross lesion size was measured, and histologic analysis with hematoxylin and eosin and nicotinamide adenine dinucleotide staining was performed. RESULTS The 1000 V/cm ablations had no gross or histologic lesions. A factorial analysis of variance demonstrated that day (p = 0.56), exposure (p = 0.33), and voltage (p = 0.06) did not demonstrate statistical significance for affecting lesion size. For 1.0 cm probe exposure, 2000 V/cm did more closely approximate expected lesion size (p = 0.02) compared with 1500 V/cm. While significance was not seen for 1.5 cm probe exposure, 2000 V/cm often exceeded expected lesion volume. Only 1 of 4 temperature sensors, located adjacent to one of the IRE probes, noted a significant increase with increased voltage. However, all maximum temperatures remained less than 70°C. CONCLUSIONS Variation in lesion volume was seen with different ablation settings in this porcine model. Maximal energy and probe exposure settings should be utilized to ensure full coverage of target volume/mass, potentially without concern for thermal injury to renal collecting system or nearby structures.