James H. Masterson

Impact of tumour morphology on renal function decline after partial nephrectomy

To examine the association of renal morphology with renal function after partial nephrectomy (PN).

Impact of statins on nephrolithiasis in hyperlipidemic patients: a 10-year review of an equal access health care system.

AIM To investigate the impact of statin medications on urinary stone formation in hyperlipidemic patients. MATERIAL AND METHODS We searched outpatient military electronic health records from the Southwestern United States to identify adult patients with hyperlipidemia and urolithiasis. Military facilities serve active duty members, retirees, and their immediate family members. We created two predictor variables - with and without statin. The outcome variable was a diagnosis of urolithiasis. RESULTS The inception cohort included 57,232 subjects with hyperlipidemia and 1,904 subjects with nephrolithiasis. Patients taking statin medications had significantly less stone formation compared to patients not taking statin medications (3.1% vs. 3.7%, univariate OR = 0.83, 95% CI 0.76 - 0.91, p < 0.001). Statins patients were significantly older (59 vs. 45 years, p < 0.001), more likely to be female (38% vs. 34%, p < 0.001) and have co-morbidities (obesity, hypertension, diabetes, heart disease; all p < 0.001). Multivariate analysis indicated that statin medications had a protective effect against stone formation (OR = 0.51, 95% CI 0.46 - 0.57, p < 0.001), after adjusting for age, sex, and comorbidities. The risk of nephrolithiasis was not only additive for diabetes mellitus, hypertension, and obesity; more importantly it was attenuated with addition of statin use. CONCLUSION Statin medications are associated with reduced risk of urinary stones. This is the first study to demonstrate the impact of statins on nephrolithiasis. Further prospective studies are necessary to validate these findings that treatment of hyperlipidemia reduces stone risk formation.

Changes in Urine Parameters After Desert Exposure: Assessment of Stone Risk in United States Marines Transiently Exposed to a Desert Environment

PURPOSE Living in a desert environment has been associated with a higher incidence of kidney stone formation, likely because of concentrated urine output, higher production of vitamin D and genetic predisposition. We determined the changes in urinary parameters after a group of United States Marines temporarily transitioned from a temperate environment to a desert environment. MATERIALS AND METHODS A total of 50 Marines completed a questionnaire and performed 3, 24-hour urine collections before mobilization to the desert, after 30 days in the desert and 2 weeks after returning from the desert. RESULTS Daily urine output decreased 68% to 0.52 L despite marked increased fluid intake (17 L per day). Total daily urinary excretion of calcium, uric acid, sodium, magnesium and potassium in the desert decreased by 70%, 41%, 53%, 22% and 36%, respectively. Urinary pH decreased from 6.1 to 5.6 while in the desert, and citrate and oxalate had minimal changes. After their return from the desert, apart from a decrease of 22% in oxalate, there were no statistically significant differences from baseline. While in the desert, relative supersaturation risks of uric acid and sodium urate were increased 153% and 56%, respectively. Brushite relative supersaturation decreased 24%. After their return there was no statistical difference from baseline. CONCLUSIONS Our findings suggest that the kidneys preserved water and electrolytes while the Marines were subjected to the desert environment. Despite this conservation, relative saturations indicate increased risk of stones in healthy men exposed to a desert environment with rapid resolution upon return.

Demographics of Men Receiving Vasectomies in the US Military 2000–2009

Background: We hypothesize that there is a higher incidence of vasectomy within the military at a younger age based on this equal access health care system. Materials and Methods: A review of the CHAMPS military database was conducted for men receiving vasectomies from 2000 to 2009. Age at vasectomy, number of children, race, religion, and marital status were recorded and incidence was computed. Results: Total of 82,945 vasectomies was performed. The overall incidence to have a vasectomy was approximately 7.10 per 1000 men. The highest rate of occurrence was 14.4 per 1000 men in men 30–34 years old. Whites had a higher rate than blacks at 10.03 per 1000 men compared to 6.27 per 1000 men. Protestants had the highest rate at 8.44 per 1000 men, and Jewish people had the lowest at 1.86 per 1000 men. Married men had a rate of 12.3 per 1000 men, whereas single men were 1.03 per 1000 men. Conclusions: The incidence to have a vasectomy in the military was 7.10 per 1000 men, with an age adjusted rate at 8.66 per 1000 men. This information may assist primary care providers in discussing vasectomies as a permanent form of contraception.

A 10-Year Retrospective Review of Nephrolithiasis in the Navy and Navy Pilots

Purpose: Little is known about the incidence of nephrolithiasis in the United States Navy. Navy pilots must be kidney stone‐free and are often referred for treatment of small asymptomatic stones. The primary objectives of this study were to determine the incidence of nephrolithiasis and computerized tomography, proportion undergoing treatment and incidence of stone related mishaps in Navy pilots compared with other Navy personnel. Materials and Methods: We retrospectively studied the records of all Navy service members from 2002 to 2011 for nephrolithiasis based on ICD‐9 stone codes to determine the mentioned rates. We also reviewed NSC (Naval Safety Center) data for a history of accidents associated with nephrolithiasis. Rates of disease were calculated using person‐years of followup and inferential statistics were done using univariable and multivariable analyses. Results: We evaluated 667,840 Navy personnel with a total of 3,238,331 person‐years of followup. The annual incidence of nephrolithiasis was 240/100,000 person‐years with a 5‐year recurrence rate of 35.3%. On multivariable analysis pilots had nephrolithiasis incidence and treatment rates similar to those of the overall Navy population. Women had a higher incidence of nephrolithiasis compared with men (OR 1.17, p <0.0001). The rate of computerized tomography was lower in pilots than in the rest of the Navy (39 vs 66/10,000 person‐years, p <0.0001). No recorded accidents were associated with kidney stones. Conclusions: Navy pilots had a similar incidence of nephrolithiasis and were no more likely to undergo a surgical procedure. Given that no accidents were associated with nephrolithiasis, this study suggests reconsidering current military policies necessitating pilots to be completely stone‐free.

MP64-15 DETERMINANTS OF RENAL FUNCTIONAL DECLINE AFTER OPEN PARTIAL NEPHRECTOMY: A COMPARISON OF WARM, COLD, AND NON-ISCHEMIC MODALITIES

INTRODUCTION Renal functional decline after partial nephrectomy (PN) may be related to a variety of nonmodifiable and modifiable factors, including ischemia time (IT) and modality. We sought to determine the impact of these factors on renal functional degeneration after PN. MATERIALS AND METHODS Multicenter retrospective analysis (n = 347) was performed, identifying patients who underwent open PN using warm, cold, and non-ischemic techniques. Primary outcome was development of de novo chronic kidney disease (CKD), (estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2), at 1 year follow up. Univariate and multivariable analysis (MVA) were performed examining factors associated with ischemia technique and the development of de novo CKD. RESULTS Median follow up 34.7 months. Two hundred and forty-one patients underwent warm ischemic, 31 cold ischemic, and 75 clampless PN. Patient characteristics were similar between groups. Clampless group had lower mean RENAL scores (6.4) than cold (7.9, p = 0.005) and warm (7, p = 0.037) ischemia groups. Cold ischemia cohort had longer median IT than the warm cohort (50min versus 25 min, p = 0.001). There were no significant differences in proportion of patients developing de novo CKD (warm 14.9%, cold 15%, clampless 8.7%, p = 0.422). MVA demonstrated that neither ischemic modality nor IT ≥ 30 minutes was associated with development of de novo CKD, while RENAL scores of increasing complexity (RENAL score 7-9 OR 4.32, p = 0.003; RENAL score ≥ 10 OR 15.42, p < 0.001) were independently associated with de novo CKD. CONCLUSIONS Increasing tumor complexity, as indicated by the RENAL score, was an overriding determinant of post PN renal functional outcome. Prospective investigation is requisite to elucidate risk and protective factors for renal functional degeneration after PN.

Minimal incision laparoscopy assisted open pediatric pyeloplasty

Minimal incision laparoscopy-assisted open pyeloplasty (MILAP) incorporates elements of open pyeloplasty (OP) and single incision laparoscopy to improve technical ease and cosmetic outcomes. Six MILAP procedures were performed using a single transumbilical incision through which the ureteropelvic junction (UPJ) is mobilized with standard laparoscopic instrumentation. The UPJ is brought extracorporeally through a 1-cm flank incision, and a traditional Anderson-Hynes open pyeloplasty is performed. Compared with OP, perioperative outcomes were similar. Follow-up renal scans all showed improvement of obstruction. A 1-cm flank incision is the only obvious scar.

Supine Robotic-Assisted Retroperitoneal Lymph Node Dissection for Testicular Cancer

Background and Objectives: Robotic-assisted laparoscopic retroperitoneal lymph node dissection (RPLND) using a lower abdominal approach for testicular cancer is an advanced and relatively new surgical technique. Herein we describe technical modifications, review benefits, and report our initial series. Methods: A retrospective review of 16 patients from Jan 1, 2010 to Dec 31, 2012 who underwent robotic RPLND for nonseminomatous germ cell tumors was performed. Patients were positioned in 15° of Trendelenburg and tilted 15° to the right. An infraumbilical midline camera port, 3 robotic ports, and 2 assistant ports were placed in a lower abdominal configuration. Patient demographic and perioperative outcomes were assessed. Results: Twelve patients underwent staging, prospective nerve-sparing RPLNDs, and 4 underwent postchemotherapy RPLNDs. Mean age was 26.4 years with a mean body mass index of 27.4 kg/m. The cohort had a mean operative time of 357 minutes, mean estimated blood loss of 205 mL, mean hospital stay of 3.6 days, and mean postoperative morphine equivalent use of 47.1 mg. There were no conversions to open RPLND in this cohort. An average of 26.2 lymph nodes were sampled. Conclusions: Inferior approach for robotic RPLND enables a thorough dissection of the retroperitoneum, without repositioning, to meet oncologic goals. Further study to evaluate long-term outcomes is warranted.

The Utilization of Ultrasound in the Diagnosis of Urolithiasis

Ultrasound uses high-frequency sound waves to image internal structures. Ultrasound probes generally range from 2 to 20 MHz, with higher frequencies allowing greater resolution and lower frequencies allowing greater tissue penetration. As an imaging modality for urolithiasis, ultrasound is sensitive (81–96 %) and specific (100 %) for detection of renal stones and holds the additional benefit of not exposing the patient to radiation. To obtain the best diagnostic accuracy, patients should be rolled as necessary to improve viewing of the kidneys. A transvaginal exam may be performed to locate a distal ureteral stone. On ultrasound, renal calculi are visualized as curvilinear, echogenic foci with posterior acoustic shadowing. The use of tissue harmonics can help enhance shadowing of small stones. Renal ultrasound remains an effective means for detecting renal stones. Although computed tomography (CT) is more sensitive and readily available, ultrasound should be considered in evaluating renal colic in pregnant women, children, and patients in which a nonradiation technique is preferred.

Delayed Lower Urinary Tract Symptoms and Erectile Dysfunction after Acute Episode of Coccidioidal Meningitis

We present an interesting case of a 27-year-old male with coccidioidal meningitis who developed permanent erectile dysfunction (ED) and lower urinary tract symptoms 3 months after initiation of therapy. The patient presented to the urology clinic with a complaint of a weak stream, urinary urgency and frequency, as well as enuresis which were only moderately controlled with anti-cholinergics. His ED responded well to phosphodiesterase-5 inhibitors. After an extensive review of the literature, this is the first report of delayed presentation of ED and lower urinary tract symptoms secondary to coccidioidal meningitis.