Metabolic assessment of elderly men with urolithiasis

OBJECTIVE: To assess the presence of metabolic disorders in elderly men with urolithiasis. METHODS: We performed a case-control study. The inclusion criteria were as follows: (1) men older than 60 years of age and either (2) antecedent renal colic or an incidental diagnosis of urinary lithiasis after age 60 (case arm) or (3) no antecedent renal colic or incidental diagnosis of urolithiasis (control arm). Each individual underwent an interview, and those who were selected underwent all clinical protocol examinations: serum levels of total and ionized calcium, uric acid, phosphorus, glucose, urea, creatinine and parathyroid hormone, urine culture, and analysis of 24-hour urine samples (levels of calcium, citrate, creatinine, uric acid and sodium, pH and urine volume). Each case arm patient underwent two complete metabolic urinary investigations, whereas each control arm individual underwent one examination. ClinicalTrials.gov: NCT01246531. RESULTS: A total of 51 subjects completed the clinical investigation: 25 in the case arm and 26 in the control arm. In total, 56% of the case arm patients had hypocitraturia (vs. 15.4% in the control arm; p = 0.002). Hypernatriuria was detected in 64% of the case arm patients and in 30.8% of the controls (p = 0.017). CONCLUSION: Hypocitraturia and hypernatriuria are the main metabolic disorders in elderly men with urolithiasis

Metabolic assessment of elderly men with urolithiasis

OBJECTIVE: To assess the presence of metabolic disorders in elderly men with urolithiasis. METHODS: We performed a case-control study. The inclusion criteria were as follows: (1) men older than 60 years of age and either (2) antecedent renal colic or an incidental diagnosis of urinary lithiasis after age 60 (case arm) or (3) no antecedent renal colic or incidental diagnosis of urolithiasis (control arm). Each individual underwent an interview, and those who were selected underwent all clinical protocol examinations: serum levels of total and ionized calcium, uric acid, phosphorus, glucose, urea, creatinine and parathyroid hormone, urine culture, and analysis of 24-hour urine samples (levels of calcium, citrate, creatinine, uric acid and sodium, pH and urine volume). Each case arm patient underwent two complete metabolic urinary investigations, whereas each control arm individual underwent one examination. ClinicalTrials.gov: NCT01246531. RESULTS: A total of 51 subjects completed the clinical investigation: 25 in the case arm and 26 in the control arm. In total, 56% of the case arm patients had hypocitraturia (vs. 15.4% in the control arm; p = 0.002). Hypernatriuria was detected in 64% of the case arm patients and in 30.8% of the controls (p = 0.017). CONCLUSION: Hypocitraturia and hypernatriuria are the main metabolic disorders in elderly men with urolithiasis

Predicting calyceal access for percutaneous nephrolithotomy with computed tomography multiplanar reconstruction

OBJECTIVES: Objective parameters in computed tomography (CT) scans that could predict calyceal access during percutaneous nephrolithotomy have not been evaluated. These parameters could improve access planning for percutaneous nephrolithotomy. We aimed to determine which parameters extracted from a preoperative multiplanar reconstructed CT could predict renal calyceal access during a percutaneous nephrolithotomy. METHODS: From January 2009 through April 2011, 230 patients underwent 284 percutaneous nephrolithotomies at our institution. Sixteen patients presented with complete staghorn calculi, and 11 patients (13 renal units) were analyzed. Five parameters were extracted from a preoperative reconstructed CT and compared with the surgical results of percutaneous nephrolithotomy. RESULTS: Fifty-eight calyces were studied, with an average of 4.4 calyces per procedure. A rigid nephroscope was used to access a particular calyx, and a univariate analysis showed that the entrance calyx had a smaller length (2.7 vs. 3.98 cm, p = 0.018). The particular calyx to be accessed should have a smaller length (2.22 vs. 3.19 cm, p = 0.012), larger angles (117.6 vs. 67.96,

Comparison between two shock wave regimens using frequencies of 60 and 90 impulses per minute for urinary stones

PURPOSE: Two different regimens of SWL delivery for treating urinary stones were compared. METHODS: Patients with urinary stones were randomly divided into two groups, one of which received 3000 shocks at a rate of 60 impulses per minute and the other of which received 4000 shocks at 90 impulses per minute. Success was defined as stone-free status or the detection of residual fragments of less than or equal to 3 mm three months after treatment. Partial fragmentation was considered to have occurred if a significant reduction in the stone burden was observed but residual fragments of 3mm or greater remained. RESULTS: A total of 143 procedures were performed with 3000 impulses at a rate of 60 impulses per minute, and 156 procedures were performed with 4000 impulses at 90 impulses per minute. The stone-free rate was 53.1% for patients treated with the first regimen and 54.8% for those treated with the second one (p = 0.603). The stone-free rate for stones smaller than 10 mm was 60% for patients treated with 60 impulses per minute and 58.6% for those treated with 90 impulses per minute. For stones bigger than 10 mm, stone-free rates were 34.2% and 45.7%, respectively (p = 0.483). Complications occurred in 2.3% of patients treated with 60 impulses per minute and 3.3% of patients treated with 90 impulses per minute. CONCLUSION: No significant differences in the stone-free and complication rates were observed by reducing the total number of impulses from 4000 to 3000 and the frequency from 90 to 60 impulses per minute

Can we predict which patients will evolve to chronic kidney disease after nephrectomy for cortical renal tumors?

Introduction: While some studies show that patients submitted to radical nephrectomy have a higher risk of developing chronic kidney disease (CKD), some studies report that carefully selected living kidney donors do not present a higher risk for CKD. Here, we aim to study predictive factors of CKD after radical nephrectomy. Materials and Methods: Between January 2006 to January 2010, 107 patients submitted to radical nephrectomy for cortical renal tumors at our institution were enrolled in this study. Demographic data were recorded, modified Charlson-Romano Index was calculated, and creatinine clearance was estimated using abbreviated Modification of Diet in Renal Disease (MDRD) study equation. Pathological characteristics, surgical access and surgical complications were also reviewed. The end-point of the current study was new onset estimated glomerular filtration rate (eGFR) less than 60 and less than 45 mL/minute/1.73 m(2). Results: Age, preoperative eGFR, Charlson-Romano Index and hypertension were predictive factors of renal function loss, when the end-point considered was eGFR lower than 60 mL/minute/1.73 m(2). Age and preoperative eGFR were predictive factors of renal function loss, when the end-point considered was eGFR lower than 45 mL/minute/1.73 m2. Moreover, each year older increased 1.1 times the risk of eGFR lower than 60 and 45 mL/minute/1.73 m(2). After multivariate logistic regression, only age remained as an independent predictive factor of eGFR loss. Conclusion: Age is an independent predictive factor of GFR loss for patients submitted to radical nephrectomy for cortical renal tumors

Single-use versus reusable flexible ureteroscopes: a comprehensive cost-analysis decision model

Purpose: The significant improvements in flexible ureterorenoscopes have made flexible ureteroscopy the main treatment modality to target upper urinary pathologies. The purpose of this study was to critically evaluate all literature concerning the cost-effectiveness of flexible ureteroscopy comparing single-use with reusable scopes. Methods: A systematic online literature review was performed in PubMed, Embase and Google Scholar databases. Two separate urologists (GSM and FCT) performed the online search and reviewed all papers considered suitable and relevant for this analysis. Because of the paucity of high quality publications, not only prospective assessments but also case control and case series studies were included in the final analysis. All factors potentially affecting surgical costs or clinical outcomes were considered in the analysis. Results: 741 studies with the previously elected terms were found. Of those, 18 were duplicated and 77 were not related to urology procedures and were excluded. Of the remaining 646 studies, 59 published between 2000 and 2018 were considered of relevance to the pre-defined queries and were selected for further analysis. Stone free and complication rates were similar between single-use and reusable scopes. In special, urinary tract infection rate following flexible ureteroscopy is not inferior if a single-use device is used instead of a reusable scope. Operative time was in average 20% shorter if a digital scope was used, single-use or not. There is a suggestion that the learning curve is shorter with single-use devices but this is not consistent in the literature. Surgeon expertise impacts the longevity of the flexible scope. Reusable digital scopes seem to last longer than optic ones, though scope longevity is very variable worldwide. New scopes usually last three to four times more than refurbished ones and single-use ureterorenoscopes have good resilience throughout long cases. Both sterilization method and cleaning process impact scope longevity, the best results being achieved with Cidex and a dedicated nurse to take care of the sterilization process. The main factors that negatively impact device longevity regarding patient and disease are lower pole pathologies, large stone burden and non-use of a ureteral access sheath. Conclusions: The cost-effectiveness of a flexible ureteroscopy program is dependent of several aspects that must be considered when deciding whether to choose between a single-use and a reusable ureterorenoscope. Disposable devices are already a reality and will progressively become the standard as manufacturing price falls significantly.Objetivo: As melhorias significativas nos ureterorrenoscópios flexíveis tornaram a ureteroscopia flexível a principal modalidade de tratamento para as patologias de trato urinário superior. O objetivo deste estudo foi avaliar criticamente toda a literatura sobre a custo-efetividade da ureteroscopia flexível comparando aparelhos de uso único com reutilizáveis. Métodos: Uma revisão sistemática da literatura online foi realizada nas bases de dados PubMed, Embase e Google Scholar. Dois urologistas distintos (GSM e FCT) realizaram a pesquisa online e revisaram todos os trabalhos considerados adequados e relevantes para esta análise. Devido à escassez de publicações de alta qualidade, não apenas as avaliações prospectivas, mas também os estudos de casos e séries de casos foram incluídos na análise final. Todos os fatores que potencialmente afetam os custos cirúrgicos ou os desfechos clínicos foram considerados na análise. Resultados: foram encontrados 741 estudos com os termos previamente eleitos. Destes, 18 eram duplicados e 77 não tinham relação com procedimentos de urologia e foram excluídos. Dos restantes 646 estudos, 59 publicados entre 2000 e 2018 foram considerados relevantes para as consultas pré-definidas e foram selecionados para análise posterior. As taxas de complicações e livres de cálculo foram semelhantes entre os escopos de uso único e reutilizáveis. Em especial, a taxa de infecção do trato urinário após ureteroscopia flexível não é inferior se um dispositivo de uso único for usado em vez de um reutilizável. O tempo cirúrgico foi em média 20% menor se um ureteroscópio digital foi usado, seja de uso único ou não. Há uma sugestão de que a curva de aprendizado é mais curta com dispositivos de uso único, mas isso não é consistente na literatura. A experiência do cirurgião afeta a longevidade do aparelho flexível. Os aparelhos digitais reutilizáveis parecem durar mais que os ópticos, embora a longevidade seja muito variável em todo o mundo. Os novos ureteroscópios costumam durar de três a quatro vezes mais do que os recondicionados e os ureterorrenoscópios de uso único apresentam boa resiliência em casos longos. Tanto o método de esterilização como o processo de limpeza impactam a longevidade do aparelho, sendo os melhores resultados alcançados com o Cidex e uma enfermeira dedicada para cuidar do processo de esterilização. Os principais fatores que impactam negativamente a longevidade do dispositivo em relação ao paciente e à doença são patologias do polo inferior, grande volume de cálculo e não uso de uma bainha de acesso ureteral. Conclusões: A relação custo-efetividade de um programa de ureteroscopia flexível é dependente de vários aspectos que devem ser considerados ao se decidir se deve escolher entre ureterorrenoscópio de uso único e reutilizável. Os dispositivos descartáveis já são uma realidade e se tornarão progressivamente o padrão a partir do momento que o preço de fabricação cair significativamente

Pulsed Thulium:YAG laser - What is the lithotripsy ablation efficiency for stone dust from human urinary stones? Results from an in vitro PEARLS study

BACKGROUND The novel pulsed thulium:yttrium-aluminum-garnet (p-Tm:YAG) laser was recently introduced. Current studies present promising p-Tm:YAG ablation efficiency, although all are based on non-human stone models or with unknown stone composition. The present study aimed to evaluate p-Tm:YAG ablation efficiency for stone dust from human urinary stones of known compositions. METHODS Calcium oxalate monohydrate (COM) and uric acid (UA) stones were subjected to lithotripsy in vitro using a p-Tm:YAG laser generator (Thulio®, Dornier MedTech GmbH, Germany). 200 J was applied at 0.1 J × 100 Hz, 0.4 J × 25 Hz or 2.0 J × 5 Hz (average 10W). Ablated stone dust mass was calculated from weight difference between pre-lithotripsy stone and post-lithotripsy fragments > 250 µm. Estimated ablated volume was calculated using prior known stone densities (COM: 2.04 mg/mm$^{3}$, UA: 1.55 mg/mm$^{3}$). RESULTS Mean ablation mass efficiency was 0.04, 0.06, 0.07 mg/J (COM) and 0.04, 0.05, 0.06 mg/J (UA) for each laser setting, respectively. This translated to 0.021, 0.029, 0.034 mm$^{3}$/J (COM) and 0.026, 0.030, 0.039 mm$^{3}$/J (UA). Mean energy consumption was 26, 18, 17 J/mg (COM) and 32, 23, 17 J/mg (UA). This translated to 53, 37, 34 J/mm$^{3}$ (COM) and 50, 36, 26 J/mm$^{3}$ (UA). There were no statistically significant differences for laser settings or stone types (all p > 0.05). CONCLUSION To our knowledge, this is the first study showing ablation efficiency of the p-Tm:YAG laser for stone dust from human urinary stones of known compositions. The p-Tm:YAG seems to ablate COM and UA equally well, with no statistically significant differences between differing laser settings