Neel Patel

Beneficial effects of acute inhibition of the oxidative pentose phosphate pathway in the failing heart.

In vitro studies suggested that glucose metabolism through the oxidative pentose phosphate pathway (oxPPP) can paradoxically feed superoxide-generating enzymes in failing hearts. We therefore tested the hypothesis that acute inhibition of the oxPPP reduces oxidative stress and enhances function and metabolism of the failing heart, in vivo. In 10 chronically instrumented dogs, congestive heart failure (HF) was induced by high-frequency cardiac pacing. Myocardial glucose consumption was enhanced by raising arterial glycemia to levels mimicking postprandial peaks, before and after intravenous administration of the oxPPP inhibitor 6-aminonicotinamide (80 mg/kg). Myocardial energy substrate metabolism was measured with radiolabeled glucose and oleic acid, and cardiac 8-isoprostane output was used as an index of oxidative stress. A group of five chronically instrumented, normal dogs served as control. In HF, raising glycemic levels from ∼ 80 to ∼ 170 mg/dL increased cardiac isoprostane output by approximately twofold, whereas oxPPP inhibition normalized oxidative stress and enhanced cardiac oxygen consumption, glucose oxidation, and stroke work. In normal hearts glucose infusion did not induce significant changes in cardiac oxidative stress. Myocardial tissue concentration of 6P-gluconate, an intermediate metabolite of the oxPPP, was significantly reduced by ∼ 50% in treated versus nontreated failing hearts, supporting the inhibitory effect of 6-aminonicotinamide. Our study indicates an important contribution of the oxPPP activity to cardiac oxidative stress in HF, which is particularly pronounced during common physiological changes such as postprandial glycemic peaks.

Detection of lymph node metastases in penile cancer

Penile cancer (PC) is a relatively rare malignancy in the United States (US) but a greater concern in developing nations. Lymph node imaging remains critical to the staging and treatment of this disease as metastases develop in a predictable, anatomic fashion. Early surgical intervention remains a mainstay in treatment and imaging often aids in decision making. This review highlights the indications for imaging in both low-stage and advanced disease. Furthermore, we discuss the benefits and limitations of currently available imaging for staging of inguinal and pelvic lymph nodes in PC and novel modalities in development.

Percutaneous and Endoscopic Management of Nephrolithiasis in a Patient with Five Native Ureters (Trifid Right and Bifid Left Collecting System)

Abstract Triplication of the ureter is a rare urologic finding that has been well described in the literature. Patients can present with urinary tract infections, incontinence, and calculi. We present the case of a patient with extensive stone burden with right trifid and left bifid collecting systems. Stone management was performed with a multimodal approach using a combination of endoscopic and percutaneous approaches. Our systematic and staged approach highlights a method for efficacious stone treatment in a complex endourologic case.

Penile and Scrotal Strangulation due to Metal Rings: Case Reports and a Review of the Literature

Penile and scrotal entrapment from a metal ring placed at the base of the penis is a rare, but important clinical dilemma encountered in urology. Emergent presentation to the urologist, after ring placement far longer than safely practiced, risks ischemic and permanent injury to penile, scrotal, and intrascrotal structures. Treating urologists should be aware of the prevalence of metal ring use, their potential complications, and the surgical approach to their safe removal. We present two patients who were identified at our institution with strangulating injuries of retained penile rings. The first patient was a healthy, 43-year-old male with a metal ring retained for 24 hours that was safely removed with industrial bolt cutters. The second patient, a 74-year-old male, died as a result of sepsis from injuries secondary to penoscrotal ischemia after >48 hour ring retention despite prompt removal at emergent presentation. Although rare, sexual practices may include the use of penoscrotal rings. When retained, ischemic injury and edema may lead to strangulation. Emergent removal may require industrial equipment that is not within the confines of normal operating room tools. Tissue injury may be severe and sepsis life-threatening, even after ring removal.

PD40-05 DETERMINANTS OF DEFAULT FROM FOLLOW-UP CARE IN A PROSTATE CANCER SCREENING PROGRAM

RESULTS: Among 1,290 patients with available data, 585 (45%) and 284 (22%) men had any PCa and significant PCa, respectively. PSA density was significantly more predictive than PSA for detecting any and significant PCa in the PSA ranges of 4-10 and >10 ng/mL. AUC for significant prostate cancer was 0.72 (0.68, 0.77), p<0.0001 for PSA 4-10 ng/mL and 0.82 (0.75, 0.89), p<0.0001 for PSA >10 ng/mL. PSA density was significantly more predictive than PSA in detecting any and significant PCa in men with and without a prior negative biopsy. However, the incremental AUC value was larger for significant PCA than any PCA in men who had a prior negative prostate biopsy (AUC 0.81 vs 0.70, p 1⁄4 0.0042), and those who did not (AUC 0.77 vs 0.73, p 1⁄4 0.0026). CONCLUSIONS: In contrast to previous studies, we found that PSA density outperformed PSA most within the PSA range >10 ng/mL, suggesting that PSA density will save large volume prostate patients from the costs associated with the over-diagnosis of PCa. Additionally, PSA density performed best among men with a prior negative biopsy, saving these men from the burden of repeated biopsies that are likely to be negative in this population. With the current need for better markers to indicate prostate biopsy, PSA density may have significant value as a more sensitive and specific test than PSA to detect PCa when used with an extended template biopsy scheme.

PD30-08 DEVICE-RELATED DEVIATION DURING PERCUTANEOUS NEPHROLITHOTOMY: REVIEW OF THE MANUFACTURER AND USER FACILITY DEVICE EXPERIENCE (MAUDE) DATABASE

INTRODUCTION AND OBJECTIVES: Percutaneous nephrolithotomy (PCNL) for the treatment of renal calculi has traditionally been an inpatient procedure often requiring a multi-day hospitalization. Large-bore nephrostomy tubes and ureteral stents have also been traditionally placed for control of bleeding and urinary drainage. Currently, more advanced technology as well as smaller operating nephroscopes and lithotripters have made PCNL a less morbid procedure with the possibility of being done on an outpatient basis. Our aim is to show that mini-PCNL can be safely performed in a tubeless fashion on an outpatient basis. METHODS: We performed a retrospective chart review of patients that underwent mini-PCNL at our institution by a single fellowshiptrained endourologist. Only those patients who were discharged home the same day without nephrostomy tubes or ureteral stents were included. Cases were performed using mini-nephroscopes with an outer diameter of 15 to 17.5-Fr. RESULTS: There were 15 patients included for analysis. Average age was 51.3 years. The group was 53% female and 47% male. Mean BMI and ASA score were 29.31 and 2.4, respectively. Total operative time averaged 55.6 minutes [range 27 106]. Mean estimated blood loss was 12.87-mL [range 3-30-mL]. Stone size ranged from 1.3cm to 3-cm. Left and right sided stones were split evenly. There were multiple stones in 47% of patients. Primary stone location varied, but the majority were in the renal pelvis or the lower pole. Renal access was obtained in a middle or interpolar calyx 53% of the time, and 47% in the lower pole. Laser or ultrasonic lithotripsy was utilized. FLOSEAL was administered in the tract, and no stents or nephrostomy tubes were left. All patients were discharged home. No patients were readmitted or had unplanned ER visits so far. All patients with follow-up were stone free on KUB and RUS imaging. CONCLUSIONS: Mini-PCNL using operating nephroscopes up to 17.5-Fr can be safely performed on an outpatient basis in a tubeless fashion without nephrostomy tubes or ureteral stents. Some of our patients went home with Foley catheters that were removed the following morning. With the advent of improved optics and smaller ultrasonic lithotripters, mini-PCNL is a worthwhile option for patients with renal calculi that can be accomplished safely in a cost-saving outpatient basis, all while rendering patients stone free with one procedure. With changes in reimbursement for hospitals and physicians in the future, outpatient mini-PCNL could serve as a sound option for those with moderate to large renal stones who wish to be rendered stone free in one operation and avoid ureteral stents.

Hyper IgE Syndrome and Renal Cell Carcinoma

Hyper IgE Syndrome (HIES) is an immunodeficiency disorder characterized by increased serum levels of IgE, eczema, and recurrent cutaneous and pulmonary infections. In this report, we present, to our knowledge, the first documented case of renal cell carcinoma (RCC) found in a patient with HIES. The patient received infectious disease clearance prior to obtaining a partial nephrectomy which revealed clear cell histology. Both HIES and RCC have an immunological basis for their pathophysiology and may involve common pathways. Further studies may provide insight into any possible link and clinicians should be mindful of immunocompromised patients who present with risk factors for genitourinary malignancy.