Patrick Samson

Ultrasonographic Assessment of Testicular Viability Using Heterogeneity Levels in Torsed Testicles

Purpose: Gross testicular heterogeneity on ultrasound has been associated with testis loss following testicular torsion in children. We aimed to quantify the extent of temporal heterogeneity associated with testis loss in testicular torsion cases using a noninvasive technique to determine a HI (heterogeneity index) on ultrasound images. Materials and Methods: We retrospectively studied the records of patients who presented with acute scrotal pain to the Pediatric Emergency Department over a 6‐year period. Ultrasound images of the affected testis and the unaffected contralateral testis were examined using a proprietary program to determine the extent of heterogeneity of each image. The difference between the HI of the torsed testis and that of the contralateral normal testis was termed &Dgr;HI. Receiver operating characteristics curve analysis was performed to determine the &Dgr;HI threshold for nonviability. Results: Among 529 patients who presented with acute scrotal pain 147 had testicular torsion based on surgical findings. Of these 147 patients 110 (74.8%) were found to have a viable testis while 37 (25.2%) had a nonviable testis. Using the &Dgr;HI cutoff of 0.394 or greater for nonviability, sensitivity and specificity were 100% and 94.5%, respectively. Positive and negative predictive values were 86% and 100%, respectively. Conclusions: Our results demonstrate that a quantifiable temporal gradation of heterogeneity exists and the heterogeneity index can be used as an objective parameter to determine the viability of a torsed testicle. By developing the technology to measure the heterogeneity index in real time, we could potentially identify which patients with testicular torsion have a nonviable testicle and, thus, would not require immediate surgical exploration.

PD35-04 PROSPECTIVE RANDOMIZED TRIAL OF ANTIBIOTIC PROPHYLAXIS DURATION FOR PERCUTANEOUS NEPHROLITHOTOMY: PRELIMINARY RESULTS

INTRODUCTION AND OBJECTIVES: Single institution studies have suggested possible benefit of a week of preoperative antibiotics prior to percutaneous nephrolithotomy (PNL). Yet prior studies are limited by lower methodology (Level IIa)1, including heterogeneous populations2, or utilizing quasi-sepsis definitions2. Other than the recommended peri-operative dose of IV antibiotics <24 hours per AUA Best Practice Statement, the duration/benefit of preoperative antibiotics remains unclear. We sought to perform a rigorous (adhering to CONSORT guidelines) multi-institutional trial assessing utility of preoperative PNL antibiotics for patients at low risk of infectious complications. METHODS: We performed a randomized controlled trial (RCT) coordinated across 7 academic stone centers for low risk PNL patients. Low risk patients were defined as those with negative urine cultures and under no antibiotic treatment course within 14 days of procedure, and without any urinary drains (catheters, stents, nephrostomy tubes). Patients randomized to the intervention arm received nitrofurantoin 100 mg twice daily for 7 days preceding surgery. All enrolled patients received standard preoperative dose of ampicillin (vancomycin if allergic) and gentamicin (ceftriaxone if eGFR<60 or allergic). PNL was performed per the usual practice of each treating surgeon. Baseline patient and stone characteristics were recorded. Perioperative infection related adverse events within the first 30 days were compared in both groups. RESULTS: Thirty-four patients were randomized to each arm. Adverse events occurring within the first 30 days of procedure are reported in Table 1. The infection rate after PNL in the intervention arm was 17.6% (6/34) versus 11.8% (4/34), p1⁄40.49. Two of the patients in the intervention arm with infectious complications needed readmission and two others required admission to the intensive care unit. Total length of hospital stay demonstrated no difference between the two groups (1.09 versus 1.47, p1⁄40.2). There was no mortality reported during this study period. CONCLUSIONS: There appears to be no advantage to providing one week of preoperative oral antibiotics in patients at low risk for infectious complications. Less than 24 hours peri-operative antibiotics as per AUA Best Practice Statement appears sufficient. We continue to analyze this low risk group with a more robust data set, as well as analyze preoperative antibiotic benefit in other stratified risk groups. 1. Mariappan et al. BJU Int 2006 2. Kumar et al. Urol Res 2012

PD17-02 THE USE OF CYTOLOGY DURING THE WORKUP OF PATIENTS WITH PRIMARY MICROSCOPIC HEMATURIA: GUIDELINE COMPLIANCE PATTERNS AMONG A COHORT OF ACADEMIC UROLOGISTS

INTRODUCTION AND OBJECTIVES: In an effort to improve patient autonomy, several organizations publish online data on surgeon performance. One such organization is Pro-Publica, an independent nonprofit newsroom that publishes an online 0surgeon scorecard.0 This scorecard reports calculated death and complication rates for surgeons performing elective procedures including radical prostatectomy in Medicare patients. We wanted to understand how the general public would interpret this data and how it would impact patients’ selection of surgeon. METHODS: 265 adults at the Minnesota State Fair were asked to interpret a representative image from the Pro-Publica surgeon scorecard. Participants were told that a loved one had already scheduled cancer surgery with a surgeon they trusted. They were then shown a graphic with a dot representing the point estimate complication rate and a bar representing the 95% confidence interval (CI) of their surgeon. They were also shown a graphic with 13 other surgeons’ point estimate complication rates, all of which fell within the CI of the index surgeon’s complication rate. Another surgeon with a 0.5% lower point estimate but statistically equivalent complication rate to the first surgeon was indicated on the graphic. Participants were then asked if they would recommend switching surgeons after seeing this graphic. RESULTS: The surveyed population was educated with 89% having attended or graduated from college (n1⁄4235). Median age of participants was 50 years (range 20-74) with 68% females (n1⁄4179). Participants were from 136 different zip codes predominantly in the upper Midwest. When presented with the graphic representing two surgeons with different point estimate complication rates falling within the same confidence interval, 124 or 46.8% (95% CI 41-53) of respondents would recommend switching surgeons based on this single graphic. CONCLUSIONS: Nearly half of adults surveyed would recommend switching cancer surgeons for genitourinary malignancies based on a graphical representation of surgeons’ complication rates even though there was no statistically significant difference between the two surgeons. This suggests that simplistic displays of complicated statistical data may lead to changes in medical decision-making based on random error of measurement instead of true differences in surgeon quality.