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Objective: Although, upper tract urothelial carcinoma (UTUC) is rare it is associated with a high mortality rate and frequently, followed by bladder recurrence after radical surgery. Hence, this study aimed to identify the rate of bladder recurrence and its predictive factors.Material and Methods: We reviewed the medical records of 104 patients, who were diagnosed with UTUC and had radical nephroureterectomy (RNU), at the King Chulalongkorn Memorial Hospital. We excluded patients who have concurrent bladder cancer, or had a history of bladder cancer. Various clinicopathological factors were analyzed using the log-rank test and Cox proportional hazard model.Results: The mean age at diagnosis of UTUC was 68 years, and one-third of the patients were diagnosed with pathological T3 (33.7%). The mean follow-up duration was 56 months. Bladder recurrence occurred in 39 out of 104 patients (37.5%), and the median time to recurrence was 5.8 months (interquartile range 3.6 to 11.0 months). Tumor location in the distal ureter (p-value=0.038) and history of diagnostic ureteroscopy (p-value=0.004) were significantly associated with bladder recurrence in the univariate model. However, only the history of diagnostic ureteroscopy remained significant in the multivariate analysis (p-value=0.023).Conclusion: Bladder recurrence, following RNU, occurs in one-third of patients. Potential predictive factors may include history of diagnostic ureteroscopy, and the tumor location being in the distal ureter.

Objective: To evaluate the benefit of urine neutrophil gelatinase-associated lipocalin (NGAL) measurement to predict the ureteral patency in pediatric patients undergoing pyeloplasty. Materials and Methods: Ureteropelvic junction obstruction patients who underwent unilateral dismembered pyeloplasty had urine NGAL measurements taken intraoperatively during pyeloplasty and postoperatively at six months following surgery. All patients were evaluated preoperatively and postoperatively with renal scans. Pairwise comparisons and correlation analyses were performed to determine the dynamics and benefits of urine NGAL measurement. Results: Thirteen patients were included in this pilot study with a mean age of 3.2 years at surgery. Mean intraoperative bladder urine level was 4.43 ng/mL, and median intraoperative renal pelvic urine NGAL level was 3.70 ng/mL. There was no significant difference between these two levels (p-value = 0.76). Six months after pyeloplasty, 9/13 patients demonstrated significant reduction in the bladder urine NGAL level (at least 50% reduction), and 5/13 patients showed ureteral patency based on postoperative renal scan (more than 5% improvement in differential renal function or the conversion of diuretic half time. However, the finding of significant reduction of urine NGAL level did not correlate with ureteral patency (r = -0.50, p-value = 0.08). Conclusion: Although bladder urine NGAL level reduces in most pediatric patients following pyeloplasty, this decline is not reflective of the finding of ureteral patency from renal scanning. The benefits of urine NGAL measurement in this context remain unclear and require further large-scale investigation.

Objective: Flexible ureterorenoscopy (fURS) is one of the standard treatments for renal calculi up to 20 mm. This study aims to identify factors associated with stone-free status. Materials and Methods: We included patients undergoing fURS for treatment of small to medium-size renal stone (no single stone larger than 20 mm) from April 2017 to September 2019 at King Chulalongkorn Memorial Hospital. All patients had a preoperative CT scan and postoperative imaging for comparison. We collected patient characteristics (sex, age, previous ipsilateral urinary tract surgery, preoperative ureteral stent placement), stone factors (total stone burden, stone number, stone density) and renal factors (anatomical abnormalities, stone location in a lower pole, number of caliceal involvement) and correlated the data against postoperative stone-free status (defined as residual fragment ≤ 2 mm). Results: The overall stone-free rate was 53.3%. From the univariate analysis, previous surgery, total stone burden, stone number, stone location in the lower pole, and the number of caliceal involvement were associated with stone-free status. However, only the total stone burden remained statistically significant in the multivariate analysis (p-value < 0.05). The stone-free rates were 75.9%, 57.1%, and 11.1% in the total stone burden ≤ 10 mm, 11-20 mm, > 20 mm, respectively. Conclusion: Following treatment of renal stones ≤ 20 mm with fURS, the stone-free rate was 53.3% and was significantly associated with the preoperative total stone burden.

Objective: Knowing the composition of a urinary stone is valuable in its treatment, helping to define stone etiology, guide management, and prevent stone recurrence. This study aims to identify the incidence of various stone compositions in a university-based, tertiary care hospital. Material and Method: This retrospective study was conducted at King Chulalongkorn Memorial Hospital. Data of stone composition by infrared spectroscopy were collected from all patients undergoing upper urinary tract stone removal surgery from January 2015 to December 2018. Demographic data including age, gender, comorbidities, and stone characteristics were also collected. Results: A total of 173 stone analyses were included in this study. The main stone composition was calcium oxalate monohydrate (whewellite 49.7%), calcium carbonate apatite (dahllite 34.1%), calcium oxalate dihydrate (weddellite 5.2%), magnesium ammonium phosphate (struvite 4%), and ammonium hydrogen urate (2.9%). A small proportion of uric acid (1.7%), cystine (1.7%), and calcium phosphate (brushite 0.6%) was also found. No correlation was found between stone composition and age, gender or occupation. Multivariate analysis revealed that calcium oxalate stones were more common in males than females (odds ratio=2.21, 95%CI: 1.91-4.12; p-value=0.01). Phosphate-containing stones (struvite, dahllite and brushite) were more common in patients with a history of urinary tract infection (odds ratio=3.06, 95%CI: 1.18-7.92; p-value=0.02). Conclusion: Calcium oxalate and calcium carbonate apatite were the most common stone compositions found in this study. Male gender was a risk factor for oxalate stone, and a history of urinary tract infection was a risk factor for phosphate-containing stones.

Chulalongkorn Medical Journal, 66, 1, 075-081

INTRODUCTION AND OBJECTIVE:Family history of urolithiasis is a known risk factor for kidney stones. The direct relationship between family history and the severity of clinical presentation for kidn...

Kidney stones are a source of significant morbidity which have been shown to negatively impact health related quality of life. We sought to understand the association between health related quality of life, socioeconomic status and race among patients with kidney stones.Patients with stones at a total of 11 stone centers across the United States completed the WISQOL (Wisconsin Stone Quality of Life questionnaire). The patient ZIP Code™ was used to estimate household income. A mixed effects regression model was constructed for analysis with ZIP Code as the random intercept.A total of 2,057 stone formers completed the WISQOL. Lower income was independently associated with significantly lower health related quality of life (β = 0.372, p = 0.014), as were nonwhite race (β = -0.299, p = 0.001), unemployed work status (β = -0.291, p = 0.008), female gender (β = -0.204, p0.001), body mass index greater than 40 kg/mLower income, nonwhite race and unemployed work status were independently associated with lower health related quality of life among patients with kidney stones. While clinical characteristics such as body mass and stone disease severity were also associated with health related quality of life, this study shows that socioeconomic factors are similarly important. Further research to understand the specific mechanisms by which socioeconomic status and race impact health may lend insight into methods to optimize clinical treatment of stone formers and patients with other chronic diseases.

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues.

Background The role of laparoscopic adrenalectomy (LA) in a large adrenal tumor is controversial due to the risk of malignancy and technical difficulty. In this study, we compared the perioperative outcomes and complications of LA on large (≥ 6 cm) and ( Methods We retrospectively reviewed all clinical data of patients who underwent unilateral transperitoneal LA in our institution between April 2000 and June 2019. Patients were classified by tumor size into 2 groups. Patients in group 1 had tumor size Results Patients in group 2 were significant older (p = 0.04), thinner (p = 0.001) and had lower incident of hypertension (p = 0.001), with a significantly higher median operative time (75 vs 120 min), estimated blood loss (20 vs 100 ml), transfusion rate (0 vs 20.8%), conversion rate (0.25 vs 14.6%) and length of postoperative stays ( 4 vs 5.5 days) than in group 2 (all p p-value p-value Conclusions Laparoscopic transperitoneal adrenalectomy in large adrenal tumor ≥ 6 cm is feasible but associated with significantly worse intraoperative complications, postoperative complications, and recovery. However, most of the complications were minor and could be managed conservatively. Careful patient selection with the expert surgeon in adrenal surgery is the key factor for successful laparoscopic surgery in a large adrenal tumor. Trial registration: This study was retrospectively registered in the Thai Clinical Trials Registry on 02/03/2020. The registration number was TCTR20200312004.

Background: The role of laparoscopic adrenalectomy (LA) in a large adrenal tumor is controversial due to the risk of malignancy and technical difficulty. In this study, we compared the perioperative outcomes and complications of LA on large (≥ 6 cm) and (< 6 cm) adrenal tumors.Methods: We retrospectively reviewed all clinical data of patients who underwent unilateral LA in our institution between April 2000 and June 2019. Patients were classified by tumor size into 2 groups. Patients in group 1 had tumor size < 6 cm (n=408) and patient in group 2 had tumor size ≥ 6 cm (n=48). Demographic data, perioperative outcomes, complications, and pathologic reports were compared between groups.Results: Patients in group 2 were significant older (p=0.04), thinner (p=0.001) and had lower incident of hypertension (p=0.001), with a significantly higher median operative time (75 vs 120 min), estimated blood loss (20 vs 100 ml), transfusion rate (0 vs 20.8%), conversion rate (0.25 vs 14.6%) and length of stays (6 vs 9 days) than in group 2 (all pConclusions: Laparoscopic transperitoneal adrenalectomy in large adrenal tumor ≥ 6 cm is feasible but associated with significantly worse intraoperative complications, postoperative complications and recovery. However, most of the complications were minor and could be managed conservatively. Careful patient selection with the expertise surgeon in adrenal surgery are the key factors for successful laparoscopic surgery in a large adrenal tumor. Trial registration: This study was retrospectively registered in the Thai Clinical Trials Registry on 02/03/2020. The registration number was TCTR20200312004.

OBJECTIVE: To define how the learning curve for success in ultrasound-guided PCNL is impacted by body mass index (BMI). Previous research has shown ultrasound-guided percutaneous nephrolithotomy (PCNL) to be an effective method of nephrolithiasis treatment comparable to fluoroscopy guided PCNL. A common concern for the ultrasound-guided approach is potential imaging difficulty in the obese patient population. METHODS: A prospective cohort study of consecutive patients undergoing PCNL with ultrasound guidance for renal tract access was performed. Clinical data collected included success in gaining renal access with ultrasound guidance, patient BMI, and clinical outcomes over time. Nonparametric LOWESS regression modeling was performed in R using locally weighted scatterplot smoother (R version 3.3.3) for gradations of patients by BMI group (40). RESULTS: A total of 150 cases were examined. Case number and BMI were evaluated as continuous variables. Multivariate logistic regression revealed that BMI (p = 0.010; OR 0.93) and case number (p40 group is downward and right-shifted relative to the other two groups. CONCLUSION: The learning curve for successful ultrasound-guided PCNL is impacted by patient BMI as well as case number. Increasing BMI makes access more challenging when performing ultrasound-guided PCNL.

Reusable ureteroscope durability and need for repair are significant sources of expense and inefficiency for patients and urologists. Utilization of LithoVue™, a disposable flexible digital ureteroscope, may address some of these concerns. To identify its economic impact on clinical care, we performed a micro-cost comparison between flexible reusable fiberoptic ureteroscopes (URF-P6™) and LithoVue.For this prospective, single-center micro-costing study, all consecutive ureteroscopies performed during 1 week each in July and August 2016 utilized either URF-P6 or LithoVue ureteroscopes respectively. Workflow data were collected, including intraoperative events, postoperative reprocessing cycle timing, consumables usage, and ureteroscope cost data.Intraoperative data analysis showed mean total operating room time for URF-P6 and LithoVue cases were 93.4 ± 32.3 and 73.6 ± 17.4 minutes, respectively (p = 0.093). Mean cost of operating room usage per case was calculated at $1618.72 ± 441.39 for URF-P6 and $1348.64 ± 237.40 for LithoVue based on institutional cost rates exclusive of disposables. Postoperative data analysis revealed costs of $107.27 for labor and consumables during reprocessing for URF-P6 cases. The costs of ureteroscope repair and capital acquisition for each URF-P6 case were $957.71 and $116.02, respectively. The total ureteroscope cost per case for URF-P6 and LithoVue were $2799.72 and $2852.29, respectively.Micro-cost analysis revealed that the cost of LithoVue acquisition is higher per case compared to reusable fiberoptic ureteroscopes, but savings are realized in labor, consumables, and repair. When accounting for these factors, the total cost per case utilizing these two ureteroscopes were comparable.

Nephrolithiasis is an increasingly common ailment in the United States. Ureteroscopic management has supplanted shockwave lithotripsy as the most common treatment of upper tract stone disease. Ureteral stricture is a rare but serious complication of stone disease and its management. The impact of new technologies and more widespread ureteroscopic management on stricture rates is unknown. We describe our experience in managing strictures incurred following ureteroscopy for upper tract stone disease.Records for patients managed at four tertiary care centers between December 2006 and October 2015 with the diagnosis of ureteral stricture following ureteroscopy for upper tract stone disease were retrospectively reviewed. Study outcomes included number and type (endoscopic, reconstructive, or nephrectomy) of procedures required to manage stricture.Thirty-eight patients with 40 ureteral strictures following URS for upper tract stone disease were identified. Thirty-five percent of patients had hydronephrosis or known stone impaction at the time of initial URS, and 20% of cases had known ureteral perforation at the time of initial URS. After stricture diagnosis, the mean number of procedures requiring sedation or general anesthesia performed for stricture management was 3.3 ± 1.8 (range 1-10). Eleven strictures (27.5%) were successfully managed with endoscopic techniques alone, 37.5% underwent reconstruction, 10% had a chronic stent/nephrostomy, and 10 (25%) required nephrectomy.The surgical morbidity of ureteral strictures incurred following ureteroscopy for stone disease can be severe, with a low success rate of endoscopic management and a high procedural burden that may lead to nephrectomy. Further studies that assess specific technical risk factors for ureteral stricture following URS are needed.

Maintenance of flexible ureteroscopes can involve high costs and administrative burden. Instrument fragility necessitates eventual repair, rendering scopes inaccessible during refurbishment. We conducted a multi-institutional prospective cohort study to identify perioperative factors influencing flexible ureteroscope durability. Patients undergoing flexible ureteroscopy (URS) at six United States endourology centers were enrolled between August 2014 and June 2015. Surgeon self-reported concern and satisfaction with scope performance as well as upward and downward angles of deflection for each scope tip were measured before and after each procedure. The need for scope repair was determined by the operating surgeon at the time of the procedure and recorded. 424 URS cases using 74 flexible ureteroscopes were identified. Scope repair was required in 28 cases (6.6%) involving 26 scopes (35.1%). Upon univariate analysis, shorter patient height, absence of guidewire use, presence of a ureteral access sheath (UAS), longer procedure time, larger stone size, lithotrite type, surgeon training level, and self-reported concern were associated with scope repair. Upon multivariate analysis, UAS use (OR = 2.53, p = 0.005) and degree loss of scope upward flexion during a case (OR = 1.02, p = 0.03) increased the odds of a scope needing repair while the use of safety guidewire decreased the odds of a scope repair (OR = 0.50, p = 0.045). Lithotrite use and surgeon concern were associated with degree loss of scope upward flexion. The use of a UAS, absence of a safety guidewire, and the loss of upward ureteroscope flexion should be considered when evaluating means of optimizing reusable ureteroscope durability.

We compared contrast enhanced ultrasound and fluoroscopic nephrostography in the evaluation of ureteral patency following percutaneous nephrolithotomy.This prospective cohort, noninferiority study was performed after obtaining institutional review board approval. We enrolled eligible patients with kidney and proximal ureteral stones who underwent percutaneous nephrolithotomy at our center. On postoperative day 1 patients received contrast enhanced ultrasound and fluoroscopic nephrostogram within 2 hours of each other to evaluate ureteral patency, which was the primary outcome of this study.A total of 92 pairs of imaging studies were performed in 82 patients during the study period. Five study pairs were excluded due to technical errors that prevented imaging interpretation. Females slightly predominated over males with a mean ± SD age of 50.5 ± 15.9 years and a mean body mass index of 29.6 ± 8.6 kg/mA contrast enhanced ultrasound nephrostogram can be safely performed to evaluate for ureteral patency following percutaneous nephrolithotomy. This imaging technique was mostly concordant with fluoroscopic findings. Most discordance was likely attributable to the higher sensitivity for patency of contrast enhanced ultrasound compared to fluoroscopy.

IntroductionEndoscopic tools have provided versatile examination and treatment for kidney stone procedures. Despite endourologists researching urinary stone disease using endoscopes to collect tissue, this tissue collection method is limited. Endoscopically removed tissues are small in size, restricting the types of genome-based examination possible. We investigated a new method of renal papilla biopsy and RNA extraction to establish a genomic research methodology for kidney stone disease.Patients and methodsWe conducted a prospective multi-institutional study and collected renal papilla specimens from consecutive percutaneous nephrolithotomy and ureteroscopy (URS) cases performed for removal of upper urinary tract stones. Renal papilla tissue was extracted using ureteroscopic biopsy forceps after stone removal. RNA was extracted using two different extraction kits, and their quantity and quality were examined. Additionally, the impact of biopsy on surgical complications was compared between cases performed with and without biopsy by matched case-control analysis adjusted for age, gender, body mass index, bilaterality, and stone burden.ResultsA total of 90 biopsies from 49 patients were performed, and the median duration between specimen collection and RNA extraction was 61 days. Both univariate and multivariate analyses showed BIGopsy® forceps usage significantly increased the total yield (p = 0.004) and quality (p = 0.001 for A260/280, p = 0.004 for A260/A230) of extracted RNA. Extraction using the RNeasy Micro Kit® also improved A260/A230, whereas reduced RNA integrity number of extracted RNA by univariate and multivariate analyses (p = 0.002 and p

Objective To examine the cost factors associated with ultrasound and fluoroscopic guidance for percutaneous nephrolithotomy (PCNL) and to determine which method can be performed at a lower cost per case. Methods A cost comparison study was performed utilizing clinical data from a prospectively maintained research database. We included the most recent 33 consecutive ultrasound-guided PCNL cases in 2016 and the most recent 40 consecutive fluoroscopy-guided PCNL cases before the operative surgeon transitioned to ultrasound guidance in May 2014. The total operative time and clinical outcomes were examined. Costs were extracted from the institution accounting systems and given a uniform multiplier to protect institutional financial reporting confidentiality. Comparisons were made using the Student t test and the chi-squared test. Results After excluding outliers, 71 PCNL procedures were included in the analysis. Demographic data and stone characteristics were not different between ultrasound-guided and fluoroscopy-guided groups. However, the mean operative time for ultrasound-guided PCNL was significantly shorter (99.8 ± 27.0 vs 144.9 ± 55.1 minutes, P

Purpose To demonstrate the feasibility of contrast material-enhanced ulrasonographic (US) nephrostograms to assess ureteral patency after percutaneous nephrolithotomy (PCNL) in this proof-of-concept study. Materials and Methods For this HIPAA-compliant, institutional review board-approved prospective blinded pilot study, patients undergoing PCNL provided consent to undergo contrast-enhanced US and fluoroscopic nephrostograms on postoperative day 1. For contrast-enhanced US, 1.5 mL of Optison (GE Healthcare, Oslo, Norway) microbubble contrast agent solution (perflutren protein-type A microspheres) was injected via the nephrostomy tube. Unobstructed antegrade ureteral flow was defined by the presence of contrast material in the bladder. Contrast-enhanced US results were compared against those of fluoroscopic nephrostograms for concordance. Results Ten studies were performed in nine patients (four women, five men). Contrast-enhanced US demonstrated ureteral patency in eight studies and obstruction in two. One patient underwent two studies, one showing obstruction and the second showing patency. Concordance between US and fluoroscopic assessments of ureteral patency was evaluated by using a Clopper-Pearson exact binomial test. These results were perfectly concordant with fluoroscopic nephrostogram results, with a 95% confidence interval of 69.2% and 100%. No complications or adverse events related to contrast-enhanced US occurred. Conclusion Contrast-enhanced US nephrostograms are simple to perform and are capable of demonstrating both patency and obstruction of the ureter. The perfect concordance with fluoroscopic results across 10 studies demonstrated here is not sufficient to establish diagnostic accuracy of this technique, but motivates further, larger scale investigation. If subsequent larger studies confirm these preliminary results, contrast-enhanced US may provide a safer, more convenient way to evaluate ureteral patency than fluoroscopy. © RSNA, 2016 Online supplemental material is available for this article.

Ultrasound-guided percutaneous nephrolithotomy (PCNL) has become increasingly utilized. Patients with nondilated collecting systems represent a challenge: the target calix is often difficult to visualize. Here we report pilot study results for retrograde ultrasound contrast injection to aid in percutaneous renal access during ultrasound-guided PCNL.From April to July 2016, consecutive patients over the age of 18 years with nondilated collecting systems on preoperative imaging who presented for PCNL were enrolled. B-mode ultrasound imaging was compared with contrast-enhanced mode with simultaneous retrograde injection of Optison™ via an ipsilateral ureteral catheter.Five patients (four males and one female) with renal stones underwent PCNL with retrograde ultrasound contrast injection during the study period. Mean body mass index was 28.3 ± 5.6 kg/mRetrograde ultrasound contrast injection as an aide for renal puncture during PCNL is a feasible technique. By improving visualization of the collecting system, it facilitates needle placement in challenging patients without hydronephrosis. Future larger scale studies comparing its use to standard ultrasound-guided technique will be required to validate this concept.

Objective To identify factors associated with successful ultrasound guidance for each surgical step of ultrasound-guided percutaneous nephrolithotomy (PCNL). Patients and Methods Consecutive patients undergoing PCNL between March 2015 and June 2016 were prospectively enrolled. An attempt was made to use ultrasound guidance in renal access, tract dilation, and nephrostomy tube placement for each patient. For steps during which ultrasound guidance was unsuccessful, fluoroscopic screening was applied. Regression analysis identified patient characteristics associated with successful use of ultrasound guidance. Results A total of 96 patients composed this cohort, with a mean body mass index of 28.7 kg/m 2 . Mean stone size was 33.1 ± 18.9 mm, and no hydronephrosis was found in 63.5% of cases. Fluoroscopic screening was required for renal access in 27 cases (28.1%), tract dilation in 38 (39.6%), and nephrostomy tube placement in 80 (83.3%). Multivariate analysis demonstrated that successful ultrasound guidance was significantly associated with the presence of hydronephrosis for renal access and the absence of staghorn calculi for tract dilation. Ultrasound-guided nephrostomy tube placement appeared linked to surgeon experience. Conclusion To achieve completely x-ray–free ultrasound-guided PCNL, the ideal patient should have a hydronephrotic collecting system with no staghorn stone present. For practitioners looking to adopt ultrasound guidance into their PCNL practice, these represent the most appropriate patients to safely initiate a surgical experience.

Objective To determine social factors associated with advanced stone disease (defined as unilateral stone burden >2 cm) at time of presentation to a regional stone referral center. Little is known about social determinants of urolithiasis. We hypothesize that socioeconomic factors impact kidney stone severity at intake to referral centers. Methods A retrospective review of the prospectively collected data from the Registry for Stones of the Kidney and Ureter from 2015 to 2018 was conducted to evaluate patient characteristics predictive of having a large (>2 cm) unilateral kidney stone. Data on patient age, gender, body mass index, diabetes, race, language, education level, infection, distance, income, referring regional urologist density, American Society of Anesthesiologists score, and stone analysis were evaluated. Results Complete imaging and patient variable data was present in 650 of 1142 patients including 197 patients with unilateral stone burden >2 cm. On multivariate analysis, obesity, lower education level, increased distance from the referral center, and symptoms of infection predicted for unilateral stone burden greater than 2 cm. Among 191 patients with stone analysis data present, stone type, income, and urologist density predicted for unilateral stone burden greater than 2 cm. Conclusion In addition to known biological risk factors, patients with lower education levels and from regions of lower mean income were found to be more likely to present to our tertiary care center with stone burden greater than 2 cm. More research is needed to elucidate the social and societal determinants of advanced stone disease and the impact this has on population costs for stone treatment.

Purpose: Kidney stone patients routinely have CT scans during diagnostic work-up before being referred to a tertiary center. How often these patients exceed the recommended dose limits for occupational radiation exposure of >100 mSv for 5 years and >50 mSv in a single year from CT alone remains unknown. This study aimed to quantify radiation doses from CTs received by stone patients before their evaluation at a tertiary care stone clinic. Methods: From November 2015 to March 2017, consecutive new patients enrolled into the Registry for Stones of the Kidney and Ureter (ReSKU™) had the dose-length product of every available CT abdomen/pelvis within 5 years of their initial visit recorded, allowing for an effective dose (EDose) calculation. Multivariate logistic regression analysis identified factors associated with exceeding recommended dose limits. Models were created to test radiation reducing effects of low-dose and phase-reduction CT protocols. Results: Of 343 noncontrast CTs performed, only 29 (8%) were low-dose CTs (calculated EDose 20 mSv and >50 mSv/year, respectively. Increased body mass index, number of scans, and multiphase scans were associated with exceeding exposure thresholds (p 50%. Conclusions: Stone patients referred to a tertiary stone center may receive excessive radiation from CT scans alone. Unnecessary phases and underutilization of low-dose CT protocols continue to take place. Enacting new approaches to CT protocols may spare stone patients from exceeding recommended dose limits.

INTRODUCTION AND OBJECTIVES:Greater than 60% of counties in the United States have no urologists; does this impact stone patient management? Are stone clearance rates impacted by delays in getting to see an urologist? Our objective is to investigate the impact of delays to presentation to urology clinics and delays to surgery on need for repeat kidney stone interventions.METHODS:A retrospective review of the prospectively collected data from Sept 2015 to July 2018 was conducted to investigate the relationship between delay to seeing an urologist and delay to stone surgery. Data on unilateral stone size, patient age, race, gender, education level, BMI, ASA score, procedure type, mean income per zip code, distance from hospital, history of prior stone surgery, and English as a primary language were included. Univariate analysis was performed in R using Fisher's Exact test and Welch Two Sample t-test. Multivariate analysis was performed using logistic regression. Statistical analysis was performed in R versi...

Nephrolithiasis is a significant source of morbidity, and its incidence has increased significantly over the last decades. This rise has been attributed to concurrent increasing rates of obesity, associated with a 3-time risk of developing NL. To date, the mechanism by which obesity is linked to stone formation has not been elucidated. We aimed to utilize a transcriptomics approach to discover the missing link between these two epidemic diseases. We investigated gene expression profiling of nephrolithiasis patients by two RNA-sequencing approaches: comparison between renal papilla tissue with and without the presence of calcified Randall's plaques (RP), and comparison between the papilla, medulla, and cortex regions from within a single recurrent stone forming kidney. Results were overlaid between differently expressed genes found in the patient cohort and in the severely lithogenic kidney to identify common genes. Overlay of these two RNA-sequencing datasets demonstrated there is impairment of lipid metabolism in renal papilla tissue containing RP linked to downregulation of fatty acid binding protein (FABP) 4. Immunohistochemistry of human kidney specimens and microarray analysis of renal tissue from a nephrolithiasis mouse model confirmed that FABP4 downregulation is associated with renal stone formation. In a FABP4 knockout mouse model, FABP4 deficiency resulted in development of both renal and urinary crystals. Our study revealed that FABP4 plays an important, previously unrecognized role in kidney stone formation, providing a feasible mechanism to explain the link between nephrolithiasis and metabolic syndrome.

Purpose: This aim was to study the efficacy of a vacuum erectile device (VED) in rehabilitating the erectile function of patients undergoing nerve-sparing robotic-assisted radical prostatectomy. Materials and Methods: This prospective randomized study enrolled 35 prostate cancer patients from Thailand who had intact baseline erectile function and underwent nerve-sparing robotic-assisted radical prostatectomy. These patients were randomly assigned into either a study group which applied the VED for 10 min daily for 6 months or a control group which received no additional interventions. A 5-item version of the International Index of Erectile Function (IIEF-5) score, stretched penile length, and midshaft circumference were measured at 1, 3, and 7 months after surgery, respectively. Results: The mean patient age was 65.6 years, and the mean baseline IIEF-5 score was 22.91, which were comparable between the two groups. Three patients in the study group did not follow the VED protocol due to postoperative urinary incontinence. A per-protocol analysis revealed that the mean IIEF-5 score at 7 months was significantly higher in the study group compared to the control group (11.29 ± 7.47 vs. 6.61 ± 5.33, P = 0.047). The mean midshaft circumference was also higher in the study group (9.24 ± 1.43 cm vs. 7.91 ± 0.37 cm, P = 0.002). No statistically significant difference in the mean stretched penile length between the two groups was found. Conclusion: Early VED usage for penile rehabilitation following radical prostatectomy significantly improves IIEF-5 score and better preserves penile circumference but not penile length. A larger-scale multi-institutional study is required to validate these findings.

INTRODUCTION:Cystinuria is a genetic disorder marked by elevated urinary cystine excretion and recurrent cystine nephrolithiasis. Interestingly, despite seemingly similar contralateral renal anatomy, a subset of cystinuric patients consistently form stones in only one kidney. The aim of this study is to evaluate clinical outcomes in unilateral vs bilateral cystine stone formers. PATIENTS AND METHODS:We performed a retrospective case-control study of cystinuric patients evaluated and treated at the University of California, San Francisco between 1994 and 2015 and categorized patients as either unilateral or bilateral stone formers. Clinical presentation, baseline patient demographics, stone procedures, medical therapy regimens, and long-term renal function were compared between the two groups. RESULTS:A total of 42 cystine stone patients (22 female, 20 male) were included in the analysis. The median age at first presentation was 18.5 years and median age at study conclusion was 45.5 years. Two-thirds of patients (n = 28) had a history of bilateral stones, whereas one-third (n = 14) had unilateral stones. Medical therapy regimens were similar between groups. Despite an increased average number of lifetime surgeries (7.5 sessions for bilateral vs 3.7 sessions for unilateral, p

OBJECTIVE:To compare the measured stone burden recorded between urologists and radiologists, and examine how these differences could potentially impact stone management. As current urologic stone surgery guideline recommendations are based on stone size, accurate stone measurements are crucial to direct appropriate treatment. This study investigated the discrepant interpretation that often exists between urologic surgeons and radiologists' estimation of patient urinary stone burden. MATERIALS AND METHODS:From November 2015 through August 2016, new patients prospectively enrolled into the Registry for Stones of the Kidney and Ureter (ReSKU) were included if they had computed tomography images available and an accompanying official radiologic report at the time of their urologist provider visit. Stone number and aggregate stone size were compared between the urologic interpretation and the corresponding radiologic reports. RESULTS:Of 219 patients who met the inclusion criteria, concordance between urologic and radiologic assessment of aggregate stone size was higher for single stone sizing (63%) compared with multiple stones (32%). Statistical significance was found in comparing the mean difference in aggregate stone size for single and multiple stones (P

Introduction Ultrasound guidance for percutaneous nephrolithotomy (PCNL) has gained acceptance amongst urologists given its numerous advantages over fluoroscopy. While traditionally performed in the prone position, this video demonstrates a step-by-step approach to performing PCNL in the supine position, solely under ultrasound guidance. Materials and Methods Once in the modified supine (Galdakao-modified Valdivia) position, important anatomic landmarks are identified. It is important to first orient the ultrasound probe such that its cranial side corresponds to the left of the ultrasound screen. After optimizing a target calyx, keeping the needle in the imaging plane of the probe facilitates renal access. Tract dilation under ultrasound guidance is then achieved by keeping the wire and dilators in the same imaging plane. Results The 11th and 12th ribs, paraspinous muscle, iliac crest, midaxillary line, and costal margin are the anatomic landmarks that orient the probe to the location of the kidney. Placing the ultrasound probe in the midaxillary line, parallel to the 11th rib allows the operator to identify key renal landmarks: the renal cortex, peri-pelvic fat, collecting system, kidney stone with its associated postacoustic shadow, and the intended target calyx. Controlling the needle is easiest in the longitudinal view, as the needle can be visualized from skin to target. Dilation under ultrasound relies on keeping the wire in view. The tip of the 10-French dilator is based on the location where the wire image disappears as the dilator advances. The balloon dilator tip is visualized on ultrasound reaching the appropriate depth just inside the collecting system, at which time balloon inflation results in complete dilation of the tract. Conclusions This video provides a step-by-step approach demonstrating that PCNL can be performed in the supine position using only ultrasound-guidance. This approach facilitates renal access in this position and obviates the need for radiation exposure.

PurposeCareful decontamination and sterilization of reusable flexible ureteroscopes used in ureterorenoscopy cases prevent the spread of infectious pathogens to patients and technicians. However, inefficient reprocessing and unavailability of ureteroscopes sent out for repair can contribute to expensive operating room (OR) delays. Time-driven activity-based costing (TDABC) was applied to describe the time and costs involved in reprocessing.Materials and methodsDirect observation and timing were performed for all steps in reprocessing of reusable flexible ureteroscopes following operative procedures. Estimated times needed for each step by which damaged ureteroscopes identified during reprocessing are sent for repair were characterized through interviews with purchasing analyst staff. Process maps were created for reprocessing and repair detailing individual step times and their variances. Cost data for labor and disposables used were applied to calculate per minute and average step costs.ResultsTen ureteroscopes were followed through reprocessing. Process mapping for ureteroscope reprocessing averaged 229.0 ± 74.4 minutes, whereas sending a ureteroscope for repair required an estimated 143 minutes per repair. Most steps demonstrated low variance between timed observations. Ureteroscope drying was the longest and highest variance step at 126.5 ± 55.7 minutes and was highly dependent on manual air flushing through the ureteroscope working channel and ureteroscope positioning in the drying cabinet. Total costs for reprocessing totaled $96.13 per episode, including the cost of labor and disposable items.ConclusionsUtilizing TDABC delineates the full spectrum of costs associated with ureteroscope reprocessing and identifies areas for process improvement to drive value-based care. At our institution, ureteroscope drying was one clearly identified target area. Implementing training in ureteroscope drying technique could save up to 2 hours per reprocessing event, potentially preventing expensive OR delays.

Objective To describe our ultrasound technique for confirming intraoperative, antegrade-placed ureteral stent position during laparoscopic pyeloplasty. Background Disadvantages of retrograde stent placement include the need to reposition the patient into and out of the lithotomy position. Antegrade stent placement can reduce procedure time but requires confirming appropriate distal placement into the bladder with cystoscopy, percutaneous drain placement, or instillation of methylthioninium chloride or indigo carmine. Materials and Methods A 3-way 20-French Foley catheter is placed after induction with general anesthesia. Laparoscopic transperitoneal dismembered pyeloplasty is performed. Intraoperatively, the bladder is filled retrograde with 300ccs normal saline. After completing the posterior suture line of the ureteral anastomosis, a 4.8-French, 26-cm ureteral stent is placed antegrade down the ureter using a 5-French exchange catheter and guidewire. The stent is passed over the guidewire into the bladder. The proximal curl is then placed into the renal pelvis and the anastomosis is completed. Without patient repositioning, an intraoperative bladder ultrasound is performed to identify the distal stent curl within the bladder lumen. Results This technique demonstrated that ultrasound can guide antegrade stent placement in adult, laparoscopic ureteral surgery. It eliminated the need for intraoperative repositioning of the patient for intraoperative cystoscopy to confirm stent placement and was performed successfully during 8 laparoscopic pyeloplasty cases without failure. Ultrasound is likely more sensitive compared with looking for the presence of vesicoureteral reflux after stent placement, prevents stent malposition, and avoids the use of intravesical dyes that upon reflux can stain tissues and obscure surgical planes. Conclusion Here we demonstrate successful use of intraoperative ultrasound to confirm appropriate distal stent positioning in the bladder of an adult patient following antegrade stent placement for laparoscopic dismembered pyeloplasty. To our knowledge, this has been described in pediatrics, but never in adult patients.

Ultrasound has become a mainstay tool in urologists' armamentarium for the diagnosis and management of nephrolithiasis. From starting as a rudimentary form of imaging, it has come to play a more prominent role over time, paralleling evolution in ultrasound technology. Throughout the medical community there is a growing emphasis on reducing the amount of ionizing radiation delivered to patients during routine imaging. As such there has been a resurgence of interest in ultrasound given its lack of associated radiation exposure and proven effectiveness as a diagnostic and therapeutic imaging modality. Herein, we provide a review of the history of ultrasound, how the use of ultrasound is expanding in both diagnosis and treatment of urinary stone disease, and finally how promising applications of ultrasound are shaping the future of kidney stone management.