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.

Post-Prostatectomy Male Sling Revision and Early Results.

INTRODUCTION: Male slings are an accepted form of therapy in the incontinent man with a reported 55% to 80% success rate. Failed slings may be salvaged by performing a retensioning surgical sling revision procedure. The procedure is performed through a perineal incision that partially exposes the cicatrix containing the sling. Imbricating sutures are then placed and the patient is discharged home the same day without a catheter. Operative and postoperative details of this procedure are presented. METHODS: We retrospectively analyzed the records of the first 16 patients to undergo sling revision from June 2010 to March 2013. Patient age, pad count before and after initial sling placement, sling revision and followup time were investigated. Operative time, complications and blood loss were also analyzed. RESULTS: Median operative time was 37 minutes with a median blood loss of 5 ml. There were no surgical complications. The median daily pad count decreased from 4 to 1.3 (p = 0.002). After the procedure 63% of men improved and 44% were pad-free. CONCLUSIONS: Sling revision appears promising as an easily reproducible salvage technique for failed slings.

Dyslipidemia is associated with an increased risk of nephrolithiasis.

The pathophysiology of nephrolithiasis is multifactorial. Obesity, diabetes mellitus and hypertension are implicated in its formation. Dyslipidemia (DLD) recently has received attention as well. Congruent with a vascular etiology in stone formation, DLD theoretically would predispose patients to nephrolithiasis. We investigated a possible association of DLD with nephrolithiasis. A random cohort of 60,000 patients was established by collecting the first 5,000 patient charts per month in the year 2000. After excluding pediatric patients, a retrospective study was performed by reviewing age, sex, comorbidities, and last patient follow-up. Median lipid laboratory levels also were reviewed. Descriptive statistics were performed as well as Cox proportional-hazards regression analysis, and univariate and multivariate analyses. 52,184 (22,717 women/29,467 men) patient charts were reviewed. The average age was 31.0 ± 15.2 years. On univariate analysis, DLD was associated with nephrolithiasis with a hazard ratio (HR) of 2.2 [Confidence Interval (CI), 1.9-2.5; p < 0.001] and on multivariate analysis HR = 1.2 (1.0-1.5; p = 0.033). Low-density lipoprotein and triglycerides had no association with stone disease. Patients with high-density lipoprotein (HDL) values <45 for men and <60 for women had an HR of 1.4 (1.1-1.7, 95% CI, p = 0.003) on univariate analysis and on multivariate analysis; HR = 1.27 (1.03-1.56; p = 0.024) for nephrolithiasis. DLD was associated with an increased risk of stone disease though the only specific lipid panel associated with lower nephrolithiasis was HDL. Clinicians should consider obtaining lipid levels with the intent that treatment could potentially not only mitigate atherosclerotic disease but also decrease nephrolithiasis risk.

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.

Impact of tumour morphology on renal function decline after partial nephrectomy.

OBJECTIVE: To examine the association of renal morphology with renal function after partial nephrectomy (PN). PATIENTS AND METHODS: We conducted a multi-institutional retrospective analysis of 322 PNs performed between 2003 and 2011. The RENAL nephrometry score for each lesion was determined and the estimated glomerular filtration rate (eGFR) was calculated preoperatively and at last follow-up. We divided patients into two RENAL nephrometry score groups, low (<8) and high (≥8), and analysed and compared the outcomes of each group. The primary outcome was median change in eGFR between preoperative and last follow-up (ΔeGFR). The secondary outcome was eGFR <60 mL/min/1.73 m(2) at last follow-up. Multivariable analysis was conducted to evaluate the risk factors for eGFR <60 mL/min/1.73 m(2) at last follow-up. RESULTS: The median (interquartile range) follow-up was 25.2 (13.5-39.3) months. Low (n = 165) and high (n = 157) RENAL score groups were well-matched for baseline eGFR. The median tumour size (4.2 vs 2.4 cm, P < 0.001) was greater for the high group. In all, 64% of the low and 88.2% of the high RENAL score group (P < 0.001) had decreased eGFR at last follow-up. Median eGFR was -7 for the low vs -13.8 mL/min/1.73 m(2) for the high group (P = 0.001); eGFR <60 mL/min/1.73 m(2) at last follow-up was 27.3% for the low vs 37.6% for the high group (P = 0.057). Linear regression analysis showed that for each 1-point increase in RENAL score, there was 2.5% decrease in eGFR (P = 0.002); for each 1-cm increase in tumour size, there was 1.8% decrease in eGFR (P = 0.013). Area under curve analyses showed no significant difference between RENAL score and tumour size for prediction of de novo eGFR <60 mL/min/1.73 m(2) (P = 0.920) and ΔeGFR ≥50% (P = 0.85). Multivariable analysis showed that increasing RENAL score (odds ratio [OR] 1.24, P = 0.046) and decreasing preoperative eGFR (OR 1.10, P < 0.001) were risk factors for eGFR <60 mL/min/1.73 m(2) at last follow-up. CONCLUSIONS: Increasing RENAL nephrometry score is an independent risk factor for eGFR <60 mL/min/1.73 m(2) after PN. RENAL nephrometry score may serve as an additional measure for risk stratification before PN, but further investigation is required.

Comparison of transrectal and transvaginal hybrid natural orifice transluminal endoscopic surgery partial nephrectomy in the porcine model.

OBJECTIVE: To compare the feasibility of porcine transrectal (TR) and transvaginal (TV) hybrid natural orifice transluminal endoscopic surgery (NOTES) partial nephrectomy (PN), as NOTES nephrectomy has recently been performed in the porcine model. MATERIALS AND METHODS: A total of 10 female pigs (weight 45 kg) underwent TR (n = 5) or TV (n = 5) NOTES PN. The pneumoperitoneum was created by a periumbilical 12-mm trocar, through which a laparoscope was advanced for intra-abdominal visualization. For TV-NOTES PN, a gastroscope was used to obtain TV peritoneal access. For TR-NOTES PN, a horizontal incision was made 2 cm above the dentate line, and a submucosal tunnel was created in the posterior rectal wall. The gastroscope was advanced through the submucosal tunnel and retroperitoneum to the kidney, and a peritoneal window was created. For both TR- and TV-NOTES PN, the gastroscope was exchanged for the SPIDER Surgical System. Flexible dissecting instruments and hook cautery introduced through the SPIDER Surgical System were used to mobilize the kidney. A harmonic scalpel introduced periumbilically was used to excise a portion of the lower pole. LAPRA-TY-secured sutured renorrhaphy was performed, followed by TR or TV specimen extraction. RESULTS: TR- and TV-NOTES PN was successfully performed in all 10 pigs. A comparison of TR- and TV-NOTES PN revealed no significant differences in the mean access time (29.2 vs 29.6 minutes, P = .944), operative time (196.0 vs 183.0 minutes, P = .631), and estimated blood loss (59.0 vs 54.0 mL, P = .861). Necropsy did not demonstrate abdominal injuries. CONCLUSION: We have demonstrated proof-of-principle for TR and TV-NOTES PN in swine, with comparable perioperative parameters. Preclinical survival studies are requisite to assess the potential of TR-NOTES as an alternative to TV-NOTES.

RENAL nephrometry score is associated with complications after renal cryoablation: a multicenter analysis.

OBJECTIVE: To analyze outcomes and complications of percutaneous (PRC) and laparoscopic renal cryoablation (LRC) using the radius, endophytic, nearness to collecting system, anterior/posterior, and location (RENAL) nephrometry system. METHODS: Retrospective multicenter analysis of 154 consecutive patients who underwent either ultrasound-guided LRC (n = 88) or computed tomography (CT)-guided PRC (n = 66) from March 2003 to December 2011. RENAL score and demographics were compared to postoperative complications (Clavien). Multivariable analysis was carried out for factors associated with development of postprocedure complications. RESULTS: Mean age was 68 years (94 men/60 women). Median follow-up was 34 months (range 23.6-45.6 months). Mean tumor size was 2.6 ± 1 cm. Mean RENAL score was 5.2 ± 1.4. Differences in (A)nterior/posterior component and (H)ilar domain of the RENAL scores were noted, with PRC favoring posterior tumors and hilar lesions compared to LRC (P < .001 and P = .044, respectively). There were 14.9% complications, all of which were low-grade (Clavien 1,2). There were no differences in complications between LRC and PRC (15.9% vs 13.6%, P = .82). Most common complication type was hemorrhagic in 9 of 154 patients (5.8%); significant increase in the hemorrhagic complication rate was noted for patients with "N" ("nearness") component score of 2 or 3 (5/36, or 13.9%), compared to patients with "N" score of 1 (4/115 or 3.5%, P = .033). multivariable analysis demonstrated that increasing RENAL score was associated with postprocedure complications (odds ratio [OR] = 1.37, P = .025). When separated into individual domains, multivariable analysis revealed that "N" score 3 was significantly associated with postoperative complications (OR 16.15, P = .027). CONCLUSION: Increasing RENAL score was associated development of postprocedure complications after renal cryotherapy. Further investigation is requisite to elucidate the role of RENAL nephrometry score in risk stratification prior to renal cryotherapy.

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.

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.