Trends and patterns of initial percutaneous nephrolithotomy and subsequent procedures among commercially-insured US adults with urinary system stone disease: a 10-year population-based study.

PURPOSE: To describe trends and patterns of initial percutaneous nephrolithotomy (PCNL) and subsequent procedures from 2010 to 2019 among commercially-insured US adults with urinary system stone disease (USSD). METHODS: Retrospective study of administrative data from the IBM® MarketScan® Database. Eligible patients were aged 18-64 years and underwent PCNL between 1/1/2010 and 12/31/2019. Measures of interest for analysis of trends and patterns included the setting of initial PCNL (inpatient vs. outpatient), percutaneous access (1 vs. 2-step), and the incidence, time course, and type of subsequent procedures (extracorporeal shockwave lithotripsy [SWL], ureteroscopy [URS], and/or PCNL) performed up-to 3 years after initial PCNL. RESULTS: A total of 8,348 patients met the study eligibility criteria. During the study period, there was a substantial shift in the setting of initial PCNL, from 59.9% being inpatient in 2010 to 85.3% being outpatient by 2019 (P < 0.001). The proportion of 1 vs. 2-step initial PCNL fluctuated over time, with a low of 15.1% in 2016 and a high of 22.0% in 2019 but showed no consistent yearly trend (P = 0.137). The Kaplan-Meier estimated probability of subsequent procedures following initial PCNL was 20% at 30 days, 28% at 90 days, and 50% at 3 years, with slight fluctuations by initial PCNL year. From 2010 to 2019, the proportion of subsequent procedures accounted for by URS increased substantially (from 30.8 to 51.8%), whereas SWL decreased substantially (from 39.5 to 14.7%) (P < 0.001). CONCLUSIONS: From 2010 to 2019, PCNL procedures largely shifted to the outpatient setting. Subsequent procedures after initial PCNL were common, with most occurring within 90 days. URS has become the most commonly-used subsequent procedure type.

Contemporary treatment trends for upper urinary tract stones in a total population analysis in Germany from 2006 to 2019: will shock wave lithotripsy become extinct?

PURPOSE: To describe the change in upper urinary tract stone management in Germany over a 14-year period. METHODS: Using remote data processing we analyzed the nationwide German billing data from 2006 to 2019. To analyze the clinics' case numbers and regional trends, we used the reimbursement.INFO tool based on standardized quality reports of all German hospitals. To also cover shock wave lithotripsy (SWL) as an outpatient procedure, we analyzed the research database of the Institute for Applied Health Research with a representative anonymous sample of 4 million insured persons. RESULTS: The number of inpatient interventional therapies for upper tract urolithiasis in Germany increased from 70,099 cases in 2006 to 94,815 cases in 2019 (trend p < 0.0001). In-hospital SWL declined from 41,687 cases in 2006 to 10,724 cases in 2019 (decline of 74%; trend p < 0.0001). The percentage of SWL as an outpatient procedure increased between 2013 and 2018 from 36 to 46% of all performed SWL, while total SWL case numbers declined. Contrarily, the number of ureteroscopies increased from 32,203 cases in 2006 to 78,125 cases in 2019 (increase of 143%; trend p < 0.0001). The number of percutaneous nephrolithotomy also increased from 1673 cases in 2006 to 8937 in 2019 (increase of 434%; trend p < 0.0001). CONCLUSION: We observed an increase in interventional therapy for upper tract urolithiasis in Germany with a dramatic shift from SWL to endoscopic/percutaneous treatment. These changes may be attributed to enormous technological advances of the endoscopic armamentarium and to reimbursement issues.

Pooled-analysis of efficacy and safety of minimally invasive versus standard percutaneous nephrolithotomy.

BACKGROUND: This study aimed to assess the efficacy and safety of minimally invasive percutaneous nephrolithotomy (MPCNL) versus standard percutaneous nephrolithotomy in patients with renal and upper ureteric stones. METHODS: We conducted a pooled analysis on randomized controlled trials (RCTs). The eligible RCTs were selected from the following databases: MEDLINE, Embase, Web of Science, and the Cochrane Library. The reference lists of retrieved studies were also investigated. RESULTS: Our analysis included 10 RCTs with 1612 patients. Pooled data from 10 RCTs revealed the following: stone-free rate (odds ratio = 1.46, 95% confidence interval (CI) [1.12,1.88], P = .004), operative time (mean difference [MD]  = 4.10, 95% CI [-1.37,9.56], P = .14), length of hospital stay (MD = -15.31, 95% CI [-29.43,-1.19], P = .03), hemoglobin decrease (MD = -0.86, 95% CI [-1.19,-0.53], P < .00001), postoperative fever (MD = 0.83, 95% CI [0.49,1.40], P = .49), and urine leakage (MD = 0.59, 95% CI [0.25,1.37], P = .22). Besides, we performed sub-group analysis based on vacuum suction effect and multiple kidney stones. For vacuum suction effect, it revealed the following: stone-free rate in vacuum suction group (P = .007) and in non-vacuum suction group (P = .19). Operative time in vacuum suction group (P = .89), non-vacuum suction group (P = .16). Postoperative fever in vacuum suction group (P = .49), non-vacuum suction group (P = .85). CONCLUSION: This pooled analysis indicated that MPCNL was a safe and effective method for treating renal stones compared with standard percutaneous nephrolithotomy. Besides, the vacuum suction effect in MPCNL played a more important role. When it comes to multiple or staghorn stones, the longer operative time in MPCNL could not be ignored.

Natural History of Post-Treatment Kidney Stone Fragments: A Systematic Review and Meta-Analysis.

PURPOSE: We assessed the literature around post-treatment asymptomatic residual stone fragments and performed a meta-analysis. The main outcomes were intervention rate and disease progression. MATERIALS AND METHODS: We searched Ovid®, MEDLINE®, Embase™, the Cochrane Library and ClinicalTrials.gov using search terms: "asymptomatic", "nephrolithiasis", "ESWL", "PCNL", "URS" and "intervention." Inclusion criteria were all studies with residual renal fragments following treatment (shock wave lithotripsy, ureteroscopy or percutaneous nephrolithotomy). Analysis was performed using 'metafor' in R and bias determined using Newcastle-Ottawa scale. RESULTS: From 273 articles, 18 papers (2,096 patients) had details of intervention rate for residual fragments. Aggregate intervention rates for ≤4 mm fragments rose from 19% (20 months) to 22% (50 months), while >4 mm fragments rose from 22% to 47%. Aggregate disease progression rates for ≤4 mm rose from 25% to 47% and >4 mm rose from 26% to 88%. However, there was substantial difference in definition of "disease progression." Meta-analysis comparing >4 mm against ≤4 mm fragments: intervention rate for >4 mm (vs ≤4 mm): OR=1.50 (95% CI 0.70-2.30), p <0.001, I2=67.6%, tau2=0.48, Cochran's Q=11.4 (p=0.02) and Egger's regression: z=3.11, p=0.002. Disease progression rate for >4 mm: OR=0.06 (95% CI -0.98-1.10), p=0.91, I2=53.0%, tau2=0.57, Cochran's Q=7.11 (p=0.07) and Egger's regression: z=-0.75, p=0.45. Bias analysis demonstrated a moderate risk. CONCLUSIONS: Larger post-treatment residual fragments are significantly more likely to require further intervention especially in the long term. Smaller fragments, although less likely to require further intervention, still carry that risk. Notably, there is no significant difference in disease progression between fragment sizes. Patients with residual fragments should be appropriately counselled and informed decision-making regarding further management should be done.

Percutaneous Nephrolithotomy in Young-Old, Old-Old, and Oldest-Old Patients: A Multicenter Study.

Introduction: To compare percutaneous nephrolithotomy (PCNL) outcomes between the elderly and young age groups and examined differences between young-old, old-old, and oldest-old patients. Methods: A retrospective analysis was conducted on 8191 renal units that underwent PCNL between September 1997 and March 2020 at three Turkish academic institutions. Patients were classified into young (18-64 years) and elderly (65+ years) age groups. The elderly age group was classified into young-old (65-69 years), old-old (70-79 years), and oldest-old (80+ years). Demographics, stone features, and perioperative and postoperative outcomes were compared between groups. The factors affecting stone-free rates and complications were determined in the elderly age group. Results: The patients' median age was 47 years (18-100) and the female to male ratio was 1:1.72. The stone-free and complication rates were 78.9% and 16.4%, respectively. General complications, blood transfusion, postoperative urinary tract infections, and major complications rate were similar between the young and elderly age groups (P = .902, P = .740, P = .659, P = .219, respectively). The stone-free rate was higher in the elderly age group (P = .002). Presence of partial or complete staghorn stones and number of stones were independently associated with stone-free rates for elderly age group patients (P = .006, P < .001, respectively). Stone burden (≥400 mm2) and presence of partial or complete staghorn stones were significantly associated with complications for the elderly age group patients (P = .038, P = .014, respectively). Conclusions: In the young-old, old-old, and oldest-old age group, PCNL appears like the preferred treatment with high stone-free rates but similar complication rates compared to their younger counterpart.

Single- versus Multiple-Tract Percutaneous Nephrolithotomy in the Surgical Management of Staghorn Stones or Complex Caliceal Calculi: A Systematic Review and Meta-analysis.

OBJECTIVE: To assess current evidence on the effectiveness and safety of single- versus multiple-tract percutaneous nephrolithotomy in the surgical management of complex caliceal calculi or staghorn stones through a comprehensive literature review. METHODS: A comprehensive literature review of articles investigating the clinical efficacy and safety of single- versus multiple-tract percutaneous nephrolithotomy was performed. Relevant literature was obtained by systematically searching PubMed, EMBASE, and the Cochrane Library through May 2020. We followed the search strategy based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The primary outcomes, including the stone-free rate (SFR), and secondary outcomes (peri- and postoperative complications and operative data) were evaluated using RevMan 5.3 statistical software. RESULTS: Ten studies involving 1844 patients with complex caliceal calculi or staghorn stones met the inclusion criteria. Single-tract percutaneous nephrolithotomy (STPCNL) had noninferior clinical efficacy with respect to the immediate SFR (odds ratio (OR) = 0.80, 95% confidence interval (CI) (0.46 to 1.38), p = 0.42) and 3-month SFR (OR = 1.22, 95% CI (0.38 to 3.92), p = 0.74) compared with multiple-tract percutaneous nephrolithotomy (MTPCNL). In addition, pooled analyses showed that STPCNL resulted in significantly lower hemoglobin decreases (MD = -0.46, 95% CI (-0.68 to -0.25), p < 0.0001), fewer blood transfusions (OR = 0.48, 95% CI (0.34 to 0.67), p < 0.0001), and fewer pulmonary complications (OR = 0.28, 95% CI (0.09 to 0.83), p = 0.02) than MTPCNL. However, the overall evidence was insufficient to suggest a statistically significant difference for other adverse events. CONCLUSION: This meta-analysis indicated that STPCNL is an effective method for treating complex caliceal calculi or staghorn stones. Compared with MTPCNL, STPCNL not only yields similarly high SFRs but also is associated with many advantages, less blood loss, fewer blood transfusions, and fewer pulmonary complications without an increase in other complications. However, the findings of this study should be further confirmed by well-designed prospective randomized controlled trials (RCTs) with a larger patient series.

The impact of nephrostomy balloon inflation volume on post percutaneous nephrolithotomy hemorrhage.

INTRODUCTION: the study aims to match different volumes of nephrostomy balloon inflation to point out the foremost effective volume size of post percutaneous nephrolithotomy (PCNL) bleeding control. METHODS: we have retrospectively reviewed "560" medical records of patients who underwent percutaneous nephrolithotomy between (the years 2017 and 2018) at Prince Hussein Urology Center. The Patients were divided into two teams, group-1 (a number of 280 patients) with nephrostomy balloon inflated concerning three ml and group-2 (a number of 280 patients) the balloon inflated concerning one ml. The preoperative and postoperative hematocrit, the operation duration, the stone size, the postoperative pain severity, the transfusion rate and the duration of hematuria between the two groups were compared during hospitalization. RESULTS: regarding patients with ages (between 18 and 68 years); the preoperative hematocrit (mean values ± SDs) was (40.35% ± 3.57) vs (39.95% ± 3.43) for groups-1 and 2, respectively; the p value=0.066. The postoperative hematocrit was (37.91% ± 3.96) vs (34.38 ± 2.78), respectively; the p value was (0.008); the blood transfusion rate was 11.2% vs 13.4% (the p value was 0.039), respectively. The Postoperative pain score was (4.93 ± 1.44) vs (3.89 ± 1.45) (the p value was 0.012), respectively. CONCLUSION: increasing the nephrostomy balloon volume to a "3cc" competes for a task to decrease bleeding which was found to be as a secure and considerable effective procedure-related factor. However, the disadvantage of this technique resulted in increasing the postoperative pain in patients undergoing such a procedure.

How does the COVID-19 pandemic affect the preoperative evaluation and anesthesia applied for urinary stones? EULIS eCORE-IAU multicenter collaborative cohort study.

Stone disease is a unique condition that requires appropriate management in a timely manner as it can result in both emergent conditions and long term effects on kidney functions. In this study it is aimed to identify the up-to-date practice patterns related to preoperative evaluation and anesthesia for stone disease interventions during COVID-19 pandemic. The data of 473 patients from 11 centers in 5 different countries underwent interventions for urinary stones during the Covid-19 pandemic was collected and analyzed retrospectively. Information on the type of the stone related conditions, management strategies, anesthesiologic evaluation, anesthesia methods, and any alterations related to COVID-19 pandemic was collected. During the preoperative anesthesia evaluation thorax CT was performed in 268 (56.7%) and PCR from nasopharyngeal swab was performed in 31 (6.6%) patients. General anesthesia was applied in 337 (71.2%) patients and alteration in the method of anesthesia was recorded in 45 (9.5%) patients. A cut-off value of 21 days was detected for the hospitals to adapt changes related to COVID-19. Rate of preoperative testing, emergency procedures, conservative approaches and topical/regional anesthesia increased after 21 days. The preoperative evaluation for management of urinary stone disease is significantly affected by COVID-19 pandemic. There is significant alteration in anesthesia methods and interventions. The optimal methods for preoperative evaluation are still unknown and there is discordance between different centers. It takes 21 days for hospitals and surgeons to adapt and develop new strategies for preoperative evaluation and management of stones.

Are Routine Laboratory Investigations Necessary Following Percutaneous Nephrolithotomy?

OBJECTIVE: To determine how effective routine postoperative blood work is in identifying complications after percutaneous nephrolithotomy (PCNL), the gold standard treatment for large volume stone disease. Although major complication rates are low, hemorrhagic and sepsis-related complications are serious and can occur. Routine post-PCNL complete blood count is routinely performed by most endourologists but may be a low-value practice. METHODS: A retrospective review was performed of all PCNL procedures at our center over a 3-year period. Patient demographic, stone characteristics and postoperative data were collected and analyzed. RESULTS: Three hundred and eighty-five patients (196 female and 189 males) underwent PCNL for the treatment of urolithiasis. Mean age was 55.8 years and mean length of stay in hospital was 1.74 days. Most patients (82.9%) had neither ureteric stent nor percutaneous tube prior to PCNL. Postoperatively, 4 patients (1.0%) required a blood transfusion and 14 patients (3.6%) developed urosepsis. Patients who required either a transfusion or developed urosepsis demonstrated abnormal vital signs (tachycardia, hypotension, or fever) postoperatively. Sixteen patients (4.2%) had normal vital signs but had an extended hospital stay only to monitor abnormal blood work results. None these patients required a transfusion nor developed urosepsis but had a length of stay that was a mean of 1.5 days longer patients with normal postoperative vital signs and blood work. CONCLUSION: Abnormal vital signs alone identified all patients that required transfusion or treatment for urosepsis after PCNL. Routine complete blood count testing postoperatively may not improve detection of infectious or bleeding complications and may prolong hospital admission unnecessarily.

A Comparison of Perioperative Stone-Free Rates and Complications Following Unilateral, Single-Access Percutaneous Nephrolithotomy by Access Location in 767 Patients.

OBJECTIVE: To compare perioperative outcomes between lower, mid, and upper pole access locations for patients undergoing single-access, unilateral percutaneous nephrolithotomy (PCNL). METHODS: We queried our institutional PCNL database to include patients who had unilateral, single access procedures. We excluded patients who had a contralateral procedure during the same admission or multiaccess procedures. Patients were grouped by the site of PCNL access (lower, mid, or upper pole). Among groups, we compared postoperative day 1 (POD1) stone-free rates as measured by abdominal CT scan or plain-film X-ray and consequent need for a secondary procedure. We further compared postoperative complication rates. RESULTS: We included 767 patients for analysis, with the majority of access locations being in the lower pole (80.2%). Patients across groups had similar age, body mass index, and stone laterality. Patients with horseshoe kidneys more commonly had mid or upper pole access compared to lower pole. The percentage of patients with no residual stone fragments seen on POD 1 imaging was similar for lower, mid, and upper pole groups (57.7% vs 65.0% vs 61.6%, respectively; P = .526). Additionally, we observed no difference in the percentage of patients requiring a secondary procedure among the above groups (33.5% vs 22.5% vs 31.3%, respectively; P = .337). Patients experienced no difference in complications among groups. CONCLUSION: When performing unilateral PCNL using a single site of access, we observed no difference in stone-free rates or complications between lower, mid, and upper pole locations. Appropriate selection of access location in PCNL should be individualized to patient factors and surgeon experience.

Outcome Of Percutaneous Nephrolithotomy In Preschool And School-Age Children-Single Center Experience.

BACKGROUND: Efficacy of percutaneous nephrolithotomy in adults has been studied well in past. However, such studies are sparse within paediatric age group. As this procedure is being adopted in smaller and older children alike, we wanted to determine its safety and efficacy in two different age groups of children (preschool age and school age). METHODS: The records of 59 children undergoing PCNL at our department from December 2009 to May 2017 were reviewed retrospectively. Patients were placed into 2 age groups including children ≤7 years old (group 1) and those ≥7 years (group 2). Twenty-seven patients were put in preschool group with mean age of 4.8±2.1 years while 32 patients in school age group having mean age of 11.8±4.6 years. RESULTS: Stone size was calculated showing mean 309±55 mm2 in preschool and 324±63 mm2 in school age group respectively (p=0.1). The mean operative time was 150.1±38.7 minutes and 166.3±39.6 minutes in the preschool and school age children respectively (p=0.1). The mean length of hospital stay was 3.1±1.4 days and 2.9±1.3 days in preschool and school going children (p=0.5). The stone clearance with PCNL was seen in 96.3% (pre-school group) and 93.75% (school age group) as monotherapy (p=0.1), which increased to 100% after combining it with extracorporeal shock wave lithotripsy. CONCLUSIONS: PCNL is equally effective in both pre-school and school age groups in terms of stone free rates. Complication rates were not different between the two groups.

Risk factors of calculi in upper urinary tract after radical cystectomy with urinary diversion. / Factores de riesgo de formación cálculos en el tracto urinario superior tras cistectomía radical con derivación urinaria.

INTRODUCTION AND OBJECTIVES: The study was conducted to identify the risk factors of upper tract stone formation in patients with diversions after radical cystectomy (RC). MATERIALS AND METHODS: All patients with diversion after RC were collected in our center from January 2005 to December 2013. Three different common diversions were included: Orthotopic neobladder (ON: 168 patients), Ileal Conduit (IC: 93 patients) or Ureterocutaneostomy (UC: 104 patients). Univariable and multivariable logistic regression analysis were conducted to identify the independent predictors of stone formation in the upper tract. RESULTS: A total of 365 consecutive patients (316 males, 49 females) were included. At a median follow-up of 48 months (range 12-65 months), 36 patients (9.9%) developed upper tract stone. Among them, 26 (72.2%), 5 (13.9%) and 5 (13.9%) patients underwent ON, IC and UC, respectively. 25 patients had renal stone and 11 ureter stone. Minimally invasive operations (endoscopic laser lithotripsy via the anterograde or retrograde approach in 24 cases, percutaneous nephrolithotomy in 9 cases and shock wave lithotripsy in 3 cases) were carried out successfully in all stone cases. On univariable and multivariable logistic regression analysis, diabetes mellitus, hypertension, urinary tract infection (UTI), anastomotic stenosis and types of diversions (P<.05) were positively associated with upper tract stone formation. CONCLUSIONS: The variable predictors of upper tract stone may contain diabetes mellitus, hypertension, UTI, anastomotic stenosis and types of diversion.

Nationwide Readmission Rates Following Percutaneous Nephrolithotomy: Does Age Matter?

Introduction/Objectives: Despite minimal evidence that evaluates the effect of age on percutaneous nephrolithotomy (PCNL) morbidity, pediatric and elderly patients are considered high-risk groups. Our objective was to assess the effect of the extremes of ages on PCNL readmission and postoperative complication rates. Methods: We identified all PCNL encounters in the 2013 and 2014 Nationwide Readmission Database. Encounters were divided into five age groups: pediatric (<18 years old), young adult (18-25 years old), adult (26-64 years old), geriatric (65-74 years old), and elderly (≥75 years old). Weighted descriptive statistics were used to describe population demographics. We fit an adjusted weighted logistic regression model for 30-day readmission and complication rates. Results: We identified 23,357 encounters. Testing average effect of pediatric and elderly encounters to all other age groups did not reveal a difference in odds for 30-day readmissions, but did result in increased odds for 30-day GU readmissions (odds ratio: 17.7 [95% confidence interval (CI): 2.65-118.9]; p = 0.003). Compared to all other age groups, elderly encounters had 7.5 (95% CI: 2.5-22.7; p = 0.0004) times the odds of a 30-day readmission and 68.3 (95% CI: 29.1-160.4; p < 0.0001) times the odds of a postoperative complication. Conclusions: When comparing the average effect of the extremes of ages to all other age groups, we did not find evidence to suggest a difference in odds for 30-day GU readmissions, but did find increased odds for complications. Further examination revealed that PCNL encounters of elderly patients had significantly increased odds for both readmission and complications, whereas PCNL encounters of pediatric patients did not.

Contemporary Trends in Percutaneous Nephrolithomy Across New York State: A Review of the Statewide Planning and Research Cooperative System.

Introduction and Objectives: Percutaneous nephrolithotomy (PCNL) is a complex multistep surgery that has shown a steady increase in use for the past decade in the United States. We sought to evaluate the trends and factors associated with PCNL usage across New York State (NYS). Our goal was to characterize patient demographics and socioeconomic factors across high-, medium-, and low-volume institutions. Materials and Methods: We searched the NYS, Statewide Planning and Research Cooperative System (SPARCS) database from 2006 to 2014 using ICD-9 Procedure Codes 55.04 (percutaneous nephrostomy with fragmentation) for all hospital discharges. Patient demographics including age, gender, race, insurance status, and length of hospital stay were obtained. We characterized each hospital as a low-, medium-, or high-volume center by year. Patient and hospital demographics were compared and reported using chi-square analysis and Student's t-test for categorical and continuous variables, respectively, with statistical significance as a p-value of <0.05. Results: We identified a total of 4576 procedures performed from 2006 to 2014 at a total of 77 hospitals in NYS (Table 1). Total PCNL volume performed across all NYS hospitals increased in the past decade, with the greatest number of procedures performed in 2012 to 2013. Low-volume institutions were more likely to provide care to minority populations (21.4% vs 17.3%, p < 0.001) and those with Medicaid (25.5% vs 21.5%, p < 0.001). High-volume institutions provided care to patients with private insurance (42.1% vs 34.0%, p < 0.001) and had a shorter length of stay (3.3 days vs 4.1 days, p < 0.001). Conclusion: Our data provide insight into the patient demographics of those treated at high-, medium-, and low-volume hospitals for PCNL across NYS. Significant differences in race, insurance status, and length of stay were noted between low- and high-volume institutions, indicating that racial and socioeconomic factors play a role in access to care at high-volume centers.

Analysis of factors affecting radiation exposure during percutaneous nephrolithotomy procedures.

OBJECTIVES: To measure and analyse various factors affecting radiation exposure (RE) to surgeons during percutaneous nephrolithotomy (PCNL). PATIENTS AND METHODS: A total of 212 patients who underwent PCNL were analysed. Informed consent was obtained from all enrolled patients. Ultrasonography/fluoroscopy guided punctures were done. The tract was dilatated and sheath placement done after which the procedure was completed in a routine fashion. A JJ or ureteric catheter or percutaneous nephrostomy (PCN) tube was placed as per the merit of the case. A digitalised mobile surgical C-arm image-intensifier system was used in all cases. RE was determined using a pen dosimeter worn outside the lead apron of the surgeon at the level of the chest for uniformity and was recorded on a per case basis at the end of the procedure. Data were recorded for analysis with respect to relevant parameters. Multivariate regression analysis was used to identify various parameters which affect RE (mSv). RESULTS: The parameters analysed included: age, number and size of stones, body mass index (BMI) of patients, Hounsfield unit of stone (HU), degree of hydronephrosis, number of tracts, mode of access to pelvicalyceal system (PCS), sheath size (F), operative time (min), placement of a JJ or ureteric catheter or PCN tube, and kV used for exposure. There was a significant statistical relationship between stone volume (P < 0.001), number of tracts (P < 0.001), mode of access to PCS (P = 0.001), and sheath size (P = 0.002), with RE. The HU had a negative relationship, with a decrease in HU causing increased RE (P = 0.002). BMI, number of stones, degree of hydronephrosis, operative time and placement of a JJ or ureteric catheter or PCN tube did not have any correlation with RE in our study. CONCLUSION: The mean (SD) RE per procedure was 0.21 (0.11) mSv. Increasing size and low HU of stone, increasing number of tracts, fluoroscopic access to PCS, increasing sheath size and kV were found to increase RE. Although the exposure levels are within safety limits, serial monitoring and constant vigilance are mandatory to inform surgeons.

The Durability of Active Surveillance in Patients with Asymptomatic Kidney Stones: A Systematic Review.

Introduction: The natural progression of asymptomatic kidney stones remains unclear. Such knowledge may promote value-aligned care for patients and reduce potentially unnecessary procedures. We sought to evaluate the natural history of asymptomatic kidney stones in adults undergoing active surveillance. Materials and Methods: Using themes of "Kidney Stone" and "Active Surveillance," we performed a systematic review by searching for studies in MEDLINE, all Cochrane libraries, EMBASE, Cumulative Index to Nursing and Allied Health Literature, BIOSIS, Scopus, and Web of Science from inception through October 2017-in addition to ClinicalTrials.gov, American Urological Association Annual Meeting abstracts (2014-2017), Google Scholar, and references of included studies and prior reviews. Two blinded reviewers independently extracted data and assessed methodological quality. We qualitatively summarized rates of surgical intervention (primary outcome), spontaneous stone passage, symptom development, and stone growth. We assessed the relationship between surveillance duration and rate of surgical intervention with Pearson's correlation coefficient. Results: Of 7034 unique records, 13 studies met final eligibility criteria. There was substantial variation in reported rates of surgical intervention from 6/85 (7.1%) to 80/301 (26.6%), spontaneous stone passage from 1/32 (3.1%) to 101/347 (29.1%), symptom development from 7/96 (7.3%) to 231/300 (77.0%), and stone growth from 5/96 (5.2%) to 33/50 (66.0%). Mean surveillance duration spanned from 11.3 to 80 months (range 2-180 months). Longer mean duration of surveillance did not correlate with an increase in surgical intervention rate across studies (n = 13, r = 0.01, p = 0.98), and this finding persisted when restricting analysis to observational studies (n = 9, r = 0.12, p = 0.76). Conclusions: Active surveillance appears to be a durable strategy for a majority of patients with asymptomatic kidney stones, as there was no increase in failure of watchful waiting despite increasing duration of surveillance. Higher quality studies are needed to ascertain which patients may benefit most from active surveillance.

Comparison of Guy's Stone Score and clinical research of the endourological society nomogram for predicting surgical outcomes after pediatric percutaneous nephrolithotomy: a single center study.

BACKGROUND: The aim of this study was to compare the efficacy of Guy's Stone Score (GSS) and Clinical Research of the Endourological Society (CROES) Nomogram in predicting PCNL outcomes in the pediatric patients with kidney stone. METHODS: A retrospective review of the clinical data of 120 pediatric patients who underwent PCNL between August 2004 and February 2016 was performed. Patients were grouped according to stone-free (SF) status and complication status. The patients whose history, preoperative physical examination records, biochemical analysis, imaging records were available and who did not neglect the follow-up, were included in the study. The stone size measurement and the scoring system calculation were always performed by the same surgeon. Multivariate logistic regression analysis were performed to identify the factors associated with SF status and complication status. RESULTS: CROES score was significantly higher in SF patients compared to the patients with residual stones (P=0.009), while stone burden and GSS were significantly lower (P=0.023 and P=0.025). Median hospitalization day of patients with complications was significantly higher compared to the patients without complication (P=0.005). To have stones located in multiple calyces was the only statistically significant condition when two groups were compared (P=0.014). In multivariate analysis, CROES score was the independent factor associated with SF status (OR:0.984 95% CI: 0.959-1.010 P=0.017) and to have stones located in multiple calyces was the independent factor associated with complication status (OR:0.265 95% CI:0.087-0.808 P=0.02). CONCLUSIONS: CROES nomogram is associated with the SFR while GSS is not. Both scoring systems do not have predictive accuracy on complication status. Further studies are required to make modifications in the scoring systems in the pediatric population.

Safety and Efficacy of Bilateral Simultaneous Percutaneous Nephrolithotomy.

BACKGROUND: To evaluate the safety and efficacy of bilateral simultaneous percutaneous nephrolithotomy in one tertiary hospital in Nepal. METHODS: Retrospective study was done for all patients that underwent bilateral simultaneous percutaneous nephrolithotomy in our center from January 2010 to December 2017. The study included 36 male and 16 female patients with totalof 104renal units at an average age of 37 years (range 3 -65 years). Five patients were planned for bilateral simultaneous Percutaneous nephrolithotomy, but intraoperatively the procedure was aborted after completion of only one side due to various factors. All PCNL were performed in prone position under general anesthesia. RESULTS: In91.2% of the patients, bilateral simultaneous percutaneous nephrolithotomy could be performed as planned. Average time required for bilateral simultaneous percutaneous nephrolithotomy was 94 ± 38.8mins (range 25 - 170 mins) with average hemoglobin drop of 1.85 ± 1.30gm% (range 0.1 - 4.2gm%) and no significant change in serum creatinine levels. Multiple access tracts (>1) had to be created in 3 renal units. Most of the renal stones were Guy's stone score (GSS) 1 and 2 whereas 15.4% were GSS of 3 and 4.Overall stone free rate was 94% with significant residual stones (>4mm) in 6 renal units which were subjected to extracorporeal shockwave lithotripsy (SWL) on a later date (Clavien-Dindo Grade: III-a). Bladder clot evacuation was done in one patient (Clavien-Dindo Grade: III-b). Blood transfusion was required in two patients and two patients developed postoperative sepsis (Clavien-Dindo Grade: II). One patient developed hydrothorax which was managed successfully (Clavien-Dindo Grade: III-a). CONCLUSIONS: Bilateral simultaneous Percutaneous nephrolithotomy is feasible and safe procedure, given that the patients are appropriately selected based upon Guy's stone score, stone burden, pelvi-calyceal anatomy and overall health status.