Methodological rigour in preclinical urology: a systematic review reporting research quality over a 14-year period.

OBJECTIVE: To investigate the prevalence and trends of essential study design elements in preclinical urological studies, as well as key factors that may improve methodological rigour, as the demand for methodological rigour in preclinical studies is increasing since research reproducibility and transparency in the medico-scientific field are being questioned. METHODS AND RESULTS: PubMed was searched to include preclinical urological studies published between July 2007 to June 2021. A total of 3768 articles met the inclusion criteria. Data on study design elements and animal models used were collected. Citation density was also examined as a surrogate marker of study influence. We performed an analysis of the prevalence of seven critical study design elements and temporal patterns over 14 years. Randomisation was reported in 50.0%, blinding in 15.0%, sample size estimation in 1.0%, inclusion of both sexes in 6.3%, statistical analysis in 97.1%, housing and husbandry in 47.7%, and inclusion/exclusion criteria in 5.0%. Temporal analysis showed that the implementation of these study design elements has increased, except for inclusion of both sexes and inclusion/exclusion criteria. Reporting study design elements were associated with increased citation density in randomisation and statistical analysis. CONCLUSIONS: The risk of bias is prevalent in 14-year publications describing preclinical urological research, and the quality of methodological rigour is barely related to the citation density of the article. Yet five study design elements (randomisation, blinding, sample size estimation, statistical analysis, and housing and husbandry) proposed by both the National Institutes of Health and Animal Research: Reporting of In Vivo Experiments guidelines have been either well reported or are being well reported over time. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022233125.

En bloc holmium laser enucleation of prostate in octogenarians and nonagenarians: clinical characteristics and outcome.

Extended longevity leads to greater numbers of elderly patients with benign prostatic hyperplasia (BPH) who seek surgical solutions. We assessed the clinical characteristics and outcomes of octogenarians and nonagenarians with BPH who underwent en bloc holmium laser enucleation of prostate (HoLEP). Retrospective cohort of all consecutive HoLEP patients treated in our medical center between January 2020 and January 2023. Cohort was divided into group aged < 80 years (n = 290) and group aged ≥ 80 years (n = 77). Their demographics, presentations, indications, and outcomes were compared. Octogenarians and nonagenarians had higher rates of indwelling catheters (p = 0.00001), chronic retention (p = 0.00006), larger prostates (p = 0.03), higher American Anesthesiology Association scores (p = 0.000001), and more antiplatelet medications (p = 0.0003) at presentation. They had longer operations (median 115 vs 90 min, respectively, p = 0.0008), longer hospital stay (median 2 vs 1 day, p = 0.01E-7), a higher complication rate (17% vs 7%, p = 0.02), and a higher transitory urinary incontinence (TUI) rate (54% vs 9%, p = 0.00001). TUI was more prevalent in the older group with indwelling catheters (61% vs, 13%, p = 0.00001). The functional outcome was similar for both age groups, and all patients could void spontaneously after the procedure. En-bloc HoLEP improves urinary symptoms and quality of life in patients ≥ 80 years of age despite larger prostates, more comorbidities, and higher complications rate, compared to younger men. HoLEP bestows a significant improvement in urologic quality of life regardless of age.

The outcomes of same-day discharge following holmium laser enucleation of the prostate (HoLEP) surgeries: our experience during the COVID-19 pandemic.

OBJECTIVE: To describe the outcomes of Same-Day Discharge (SDD) following Holmium Laser Enucleation of the Prostate (HoLEP) in patients during the COVID-19 pandemic. METHODS: A retrospective review of HoLEP surgeries at a single institution between January 2021 and March 2022 was performed. Patient demographic and operative data were collected, and postoperative outcomes were evaluated in terms of safety and efficacy and compared in both groups using a t-test and chi-square test. Logistic regression was also performed to identify factors that correlate with the failure of SDD. RESULTS: A total of 155 patients were identified; 135 patients were successfully discharged on the same day and 20 were admitted (87% SDD rate). Admitted HoLEP patients had a significantly higher median prostate-specific antigen (5.7 vs 3.9 ng/dL, P < 0.001), prostate volume (152.3 vs 100.6 mL, P < 0.001), and enucleated tissue weight (90.3 vs 56.9 g, P = 0.04) compared to the SDD group. The SDD group had a 2.9% (n = 4) readmission rate and a 5.2% (n = 7) Emergency Department (ED) visit rate. There was no significant difference in the rate of postoperative ED visits (P = 0.64), readmissions (P = 0.98), complications, and catheterization time (P = 0.98) between both groups. Preoperative predictors of SDD failure included prostate gland volume > 150 mL (OR = 7.17; CI 2.01-25.67; P < 0.01) and history of antiplatelet/anticoagulation use (OR = 6.59; CI 2.00-21.67; P < 0.01). CONCLUSION: Same-day discharge following HoLEP is a safe and effective approach that can be performed in most patients using a liberal discharge criteria and relying on postoperative findings only.

The Fate of Residual Fragments After Percutaneous Nephrolithotomy: Results from the Endourologic Disease Group for Excellence Research Consortium.

Background: Residual fragments (RFs) after percutaneous nephrolithotomy (PCNL) have a significant impact on patients' quality of life and clinical course. There is a paucity of studies that evaluate the natural history of RFs after PCNL. The objective of this study is to compare rates of reintervention, complications, stone growth, and passage in patients with RFs >4, ≤4, and ≤2 mm after PCNL. Methods: Sites from the Endourologic Disease Group for Excellence (EDGE) research consortium examined data of PCNL patients from 2015 to 2019 with at least 1-year follow-up. RF passage, regrowth, reintervention, and complications were recorded and RFs were stratified into >4 and ≤4 mm groups, as well as >2 and ≤2 mm groups. Potential predictors for stone-related events after PCNL were determined using multivariable logistic regression analysis. It was hypothesized that larger RF thresholds would result in lower passage rates, faster regrowth, and greater clinically significant events (complications and reinterventions) than smaller RF thresholds. Results: A total of 439 patients with RFs >1 mm on CT postoperative day 1 were included in this study. For RFs >4 mm, rates of reintervention were found to be significantly higher and Kaplan-Meier curve analysis showed significantly higher rates of stone-related events. Passage and RF regrowth were not found to be significantly different compared with RFs ≤4 mm. However, RFs ≤2 mm had significantly higher rates of passage, and significantly lower rates of fragment regrowth (>1 mm), complications, and reintervention compared with RFs >2 mm. On multivariable analysis, older age, body mass index, and RF size were found to be predictive of stone-related events. Conclusions: With the largest cohort to date, this study by the EDGE research consortium further confirms that clinically insignificant residual fragment is problematic for patients after PCNL, particularly in older more obese patients with larger RFs. Our study underscores the importance of complete stone clearance post-PCNL and challenges the use of Clinically insignificant residual fragment (CIFR).

Post-operative pain following percutaneous nephrolithotripsy- clinical correlates.

OBJECTIVES: Management of postoperative pain following percutaneous nephrolithotripsy (PCNL) is a significant goal. We sought to identify risk factors and clinical correlates of postoperative pain in order to improve perioperative management and patient satisfaction. MATERIALS AND METHODS: A single-center, retrospective analysis, from a prospectively maintained database, of all consecutive patients who underwent PCNL for renal calculi between January 2011 and August 2018. Postoperative pain was assessed using the visual analog scale (VAS) and analgesic use. We considered VAS score above 4 as meaningful. Pain management was standardized according to patirnt reported VAS scores. Multivariable logistic regression was performed to identify risk factors and clinical correlates. RESULTS: A total of 496 patients were analyzed. Younger age was associated with VAS above 4 on the operative day and the first postoperative following PCNL (p = 0.003 and p < 0.001, respectively). Female gender was associated with VAS above 4 in the first 2 days following the operation (p < 0.001). CONCLUSIONS: Younger age and female gender would most likely benefit from pre-emptive improved pain management protocols following PCNL.

Median lobe vs. complete gland holmium laser enucleation of the prostate: A propensity score matching.

INTRODUCTION: Benign prostatic hyperplasia (BPH) is a common condition affecting aging men. While holmium laser enucleation of the prostate (HoLEP) is one of the most effective treatments for BPH, variations of the procedure, such as median lobe HoLEP (MLHoLEP), are rarely reported. Here, we report our institution's experience with partial HoLEP. METHODS: Our institutional prospective database was queried for patients having undergone median or individual lateral lobe enucleation between 2007 and 2018. A control cohort of patients who underwent standard HoLEP (sHoLEP) was identified using 1:2 propensity score matching based on age, prostate size, maximal flow rate (Qmax), postvoid residual volume (PVR), and American Urological Association symptom score (AUAss). Three and 12-month AUAss, PVR, and Qmax were compared. RESULTS: Forty-seven patients were identified as having undergone MLHoLEP. At three-month followup, AUAss (p<0.01) and incontinence rates (p=0.045) were lower for MLHoLEP patients, in addition to them having shorter operative (36.5 mins vs. 64.5 mins, p<0.01) and enucleation (13.8 mins vs. 37 mins, p<0.01) times as compared to sHoLEP patients. No difference was noted between MLHoLEP and sHoLEP cohorts with respect to age, prostate volume, PVR, or Qmax. Significant improvement in AUAss, PVR, and Q max from baseline to three and 12 months was noted overall in both groups. CONCLUSIONS: MLHoLEP could provide a surgical option with reduced operative time, quicker improvement in AUAss, and restored continence in appropriately selected patients. Ultimately, MLHoLEP represents a safe and effective treatment option to select patients who may not be eligible for or face potential morbidity concerns associated with sHoLEP.

Is medical dissolution treatment for uric acid stones more cost-effective than surgical treatment? A novel, solo practice, retrospective cost-analysis of medical vs. surgical therapy.

INTRODUCTION: Effective medical dissolution therapy (MDT) for uric acid stones is more cost-effective than surgical treatment; however, treatment failure may be associated with increased cost. We aimed to study the cost-effectiveness of MDT for uric acid stones vs. surgical management. METHODS: We performed a retrospective study within our institution of all patients receiving MDT for uric acid stones from 2008-2019. All patients had a known history of uric acid stones, urine pH ≤5.5, and <500 Hounsfield units on preoperative computed tomography (CT). The cost of treatment in the dissolution group was compared to the cost of primary surgical treatment in a theoretical matched cohort. Cost was estimated using local Medicare reimbursement scales. Statistical analysis was performed with SPSS Statistics. RESULTS: A total of 28 patients were identified, of which 18 were included in the study. Complete and partial dissolution occurred in six (33%) and four (22%) patients, respectively. Five (28%) patients developed symptoms and underwent ureteral stent placement. Ureteroscopy and percutaneous nephrolithotomy (PCNL) were each performed in three (17%) patients in whom dissolution treatment was not effective on followup CT. Following dissolution trial, six (33%) patients had residual stone burden requiring surgical intervention. The average cost of treatment, including surgeries, was $14 604 in the dissolution group vs. $17 680 in the surgical cohort. The average cost to achieve stone-free status in patients with complete, partial, or no response to dissolution were $1675, $10 124, and $21 584, respectively, while primary surgical treatment for the same patients would cost $15 037, $10 901, and $20 511, respectively. CONCLUSIONS: Successful MDT is highly cost-effective. Incomplete response to dissolution can stem from several reasons and contributes to higher costs and likely decreased quality of life.

Heterogeneity in stone culture protocols and endourologist practice patterns: a multi-institutional survey.

Kidney stone cultures can be beneficial in identifying bacteria not detected in urine, yet how stone cultures are performed among endourologists, under what conditions, and by what laboratory methods remain largely unknown. Stone cultures are not addressed by current clinical guidelines. A comprehensive REDCap electronic survey sought responses from directed (n = 20) and listserv elicited (n = 108) endourologists specializing in kidney stone disease. Questions included which clinical scenarios prompt a stone culture order, how results influence post-operative antibiotics, and what microbiology lab protocols exist at each institution with respect to processing and resulting stone cultures. Logistic regression statistical analysis determined what factors were associated with performing stone cultures. Of 128 unique responses, 11% identified as female and the mean years of practicing was 16 (range 1-46). A specific 'stone culture' order was available to only 50% (64/128) of those surveyed, while 32% (41/128) reported culturing stone by placing a urine culture order. The duration of antibiotics given for a positive stone culture varied, with 4-7 days (46%) and 8-14 days (21%) the most reported. More years in practice was associated with fewer stone cultures ordered, while higher annual volume of percutaneous nephrolithotomy was associated with ordering more stone cultures (p < 0.01). Endourologists have differing practice patterns with respect to ordering stone cultures and utilizing the results to guide post-operative antibiotics. With inconsistent microbiology lab stone culture protocols across multiple institutions, more uniform processing is needed for future studies to assess the clinical benefit of stone cultures and direct future guidelines.

Incidence of Kidney Stones in the United States: The Continuous National Health and Nutrition Examination Survey.

PURPOSE: The incidence of kidney stones in the United States is currently unknown. Here, we assessed the incidence of kidney stones using recent, nationally representative data. MATERIALS AND METHODS: We used the National Health and Nutrition Examination Survey (NHANES) from 2015 to 2018. During this time participants were asked, "Have you ever had a kidney stone?" and "In the past 12 months, have you passed a kidney stone?" Demographics analyzed include age, race, gender, body mass index, history of smoking, diabetes, hypertension, hypercholesterolemia and gout. Multivariable models were used to assess the independent impact of subject characteristics on kidney stone prevalence and incidence. RESULTS: Data were available on 10,521 participants older than age 20. The prevalence of kidney stones was 11.0% (95% CI 10.1-12.0). The 12-month incidence of kidney stones was 2.1% (95% CI 1.5-2.7), or 2,054 stones per 100,000 adults. We identified significant relationships between stone incidence and subject age, body mass index, race and history of hypertension. CONCLUSIONS: Here we find a substantially higher 12-month incidence of kidney stones than previous reports. We also validate known risk factors for stone prevalence as associated with incidence. The remarkable incidence and prevalence of stones is concerning and has implications for disease prevention and allocation of medical resources.

Outcomes and rates of dissolution therapy for uric acid stones.

INTRODUCTION: To describe the outcomes and quantify the rate of uric acid stone medical dissolution therapy using automated, software-generated stone volume measurements. METHODS: A sample of patients treated with oral dissolution therapy was reviewed from a single institution between 2008 and 2019. Baseline patient demographics, metabolic urine testing and stone characteristics were collected. Computed tomography (CT) scan images were evaluated using the quantitative Stone Analysis Software (qSAS) to obtain total stone volume (TSV), maximum diameter (MD) and stone number. Rate of dissolution using total stone volume was calculated over the treatment period. RESULTS: Twenty-seven patients were started on oral dissolution therapy, corrected for renal function. After mean duration of 180 days (range 41-531), 16 patients failed treatment resulting in surgical therapy. Twenty stones in 11 patients showed complete or partial dissolution. Compared to those who failed treatment, patients with complete or partial dissolution had lower 24 h urinary uric acid and higher treatment urine pH. Thirteen (65%) stones showed complete dissolution after a mean 167.6 days. Rate of change for responders was 4.73 mm3 or 0.6% of total stone volume per day. Time to dissolution of one half of stone volume based on total stone volume was 86 days (12.30 weeks). DISCUSSION/CONCLUSIONS: Software-calculated total stone volume may be an effective method of measuring uric acid stone response to oral alkalization therapy. Stone volume decreased by 50% after 12.3 weeks of treatment and could be an important benchmark for oral dissolution therapyoral dissolution therapy. Further studies with a larger sample and validation of the software are needed to confirm if this can be used to guide surveillance schedules for dissolution therapy.

Holmium laser enucleation of the prostate for very large benign prostatic hyperplasia (≥ 200 cc).

PURPOSE: Patients presenting with prostate gland sizes greater than 200 cc pose a unique surgical challenge to both patients and surgeons. The objective of this study is to critically assess the efficacy and risks associated with performing holmium laser enucleation of the prostate (HoLEP) on glands ≥ 200 cc. MATERIALS AND METHODS: Using a prospective maintained database, all consecutive benign prostatic hyperplasia (BPH) patients with gland size ≥ 200 cc who underwent HoLEP were included. We reported patient preoperative, intraoperative, postoperative outcomes and complications. Subgroup analysis of outcomes was stratified by gland sizes 200-299 cc and ≥ 300 cc. Univariate analysis using Kruskal-Wallis and Fisher exact test was performed to compare the two groups. RESULTS: There were 88 patients with a mean preoperative gland size of 255.9 cc (200-770 cc). Mean operative (171 vs 182 min) and enucleation time (77 vs 83 min) were not different between the two subgroups (200-299 cc vs ≥ 300 cc). Enucleation efficiency was greater for glands ≥ 300 cc (2.6 cc/min vs 2.0 cc/min, p = 0.04). Morcellation time was longer in the ≥ 300 cc group (74.5 min vs 46.8 min, p = 0.021). Mean length of stay was 1.8 ± 1.2 days and catheter duration was 2.6 ± 2.7 days. 1 (1.1%) patient required retreatment of BPH at last follow-up. The main limitation of this study is the retrospective data analysis. CONCLUSIONS: Holmium laser enucleation for prostate glands volume > 200 cc is feasible with minimal morbidity. These data further reinforce the size independence success of this procedure for BPH.

Holmium laser enucleation of the prostate using Moses 2.0 vs non-Moses: a randomised controlled trial.

OBJECTIVES: To compare the enucleation efficiency of Moses 2.0 with non-Moses technology in patients undergoing holmium laser enucleation of the prostate (HoLEP). PATIENTS AND METHODS: A double-blinded, randomised study of patients undergoing HoLEP at the Mayo Clinic in Arizona, using the Lumenis Pulse™ 120H laser system. Patients were randomised to either right lobe enucleation using Moses 2.0 and left lobe enucleation using non-Moses, or the opposite. The primary outcome was individual lobe enucleation efficiency. Secondary outcomes included individual lobe laser time, laser energy, individual enucleation and haemostasis laser energies, and fibre burn back. Two independent reviewers watched videos of the procedures and provided a subjective evaluation of the technologies. RESULTS: A total of 27 patients were included in the study. For the entire cohort, Moses 2.0 had less fibre degradation (3.5 vs 16.8 mm, P < 0.01) compared to non-Moses. When HoLEP procedures were performed by an expert, Moses 2.0 resulted in shorter enucleation time (21 vs 36.7 min, P = 0.016) and higher enucleation efficiency (1.75 vs 1.05 g/min, P = 0.05) compared to non-Moses. When HoLEP was performed by trainees, the Moses 2.0 cohort had a shorter haemostasis laser time (4.1 vs 9 min, P = 0.035) compared to the non-Moses. Fibre degradation was lower with Moses 2.0 compared to non-Moses for both experts and trainees. Moses 2.0 received a higher score than the standard technology for the incision sharpness, fibre control, tissue separation, tissue damage, haemostasis, visibility, and charring. The overall inter-observer correlation coefficient was 0.63. CONCLUSION: Moses 2.0 has higher enucleation efficiency compared to non-Moses when used by experts. The subjective evaluation favoured Moses 2.0.

The impact of phone counseling on urinary stone prevention.

OBJECTIVE: We compared the effect of standard office-based consultation (OC) and phone correspondences (PC) on dietary 24-h urinary parameters. METHODS: The medical record of all patients treated between January and April 2019 was reviewed. Only patients who had at least two consecutive 24-h urine collections were included. Linear and logistic regressions were used to investigate the difference between the changes in urinary parameters after OC and PC. RESULTS: Forty-three patients underwent 135 OC and 34 PC. Twenty-one received OC and PC, and 22 had only OC. Gender, age, the distance to stone clinic, the number of previous stone episodes, and baseline urinary parameters were similar between the groups. Patients who had both OC and PC had a longer follow-up time (51.7 vs 18.5 months, p < 0.0001) as well as more consults (Median 5.4 vs 2.5, p < 0.0001). Six (27%) patients who had only OC, and eight (38%) patients who had both OC and PC, experienced stone recurrence during the study period (p = 0.52). Following PC, there was a greater improvement in urine volume in comparison to OC (0.27 l/day vs -0.06 l/day, p = 0.034), but there was no difference in the absolute values after the consults between the groups. CONCLUSION: In established stone-clinic patients, PC was associated with a better adherence with follow-up. The 24-h urine results were similar between PC and OC. PC may be an effective alternative for urinary stone management.

Does bladder stone composition predict kidney stone composition?

INTRODUCTION Bladder stones have historically been associated with urinary stasis secondary to bladder outlet obstruction (BOO). Recent studies indicate that the role of BOO in bladder stone formation is minor. We evaluate the role of urinary lithogenic factors in bladder stone formation by comparing the compositions of bladder stones and kidney stones in patients with multi-site urinary calculi. MATERIALS AND METHODS: We identified patients who were treated for concomitant bladder stones and kidney stones between 2008-2019, and had both stone compositions available. Patients with bladder stone size < 10 mm, urinary foreign bodies, encrusted stents or tumors were excluded. Data regarding urinary symptoms, residual volumes, stone composition and 24-hours urine data were collected. RESULTS: We identified 40 males with a median age of 72 years (IQR 6-14), median residual volume of 76 mL (IQR 41-200), and a median prostate volume of 52 mL (IQR 32-102). Bladder outlet procedures were performed concomitantly with cystolitholapaxy in 21 (53%) patients. The most common bladder stone and kidney stone compositions were CaOx (47.5% and 65%), uric acid (32.5% and 22.5%), calcium phosphate (15% and 10%), and struvite (5% and 2.5%), respectively. Bladder stone and kidney stone compositions were identical in 70% of patients. Bladder stone composition was predictive of kidney stone composition, regardless of the PVR, bladder stone size, or whether an outlet procedure was performed. CONCLUSION: We found a high concordance between bladder stone and kidney stone composition, suggesting that metabolic abnormalities have a significant role in bladder stone formation. Bladder stone composition can be used to guide surgical and medical treatment for kidney stones in metabolically active stone patients.

The Clinical Implication of Incidental Prostatic Amyloidosis.

OBJECTIVE: To describe the clinicopathologic features of patients with incidental prostatic amyloidosis. PATIENTS AND METHODS: We queried the genitourinary pathology database at Mayo Clinic Arizona for prostate specimens which showed amyloid deposits. Congo red stain was used for the diagnosis of amyloidosis and amyloid subtype was performed analysis using Liquid chromatography tandem mass spectrometry. We reviewed the patient's medical charts for past or subsequent diagnosis of systemic amyloidosis and clinical course. RESULTS: Prostatic amyloidosis was identified in 7 patients between 2008-2018. Median age was 79 years (range 69-84) and median follow-up was 5 years (range 0-11). Benign prostate tissue was found in 4 patients, and prostate cancer was diagnosed in 3 patients. Amyloid subtyping was available in 6 patients and was consistent with Amyloid transthyretin Amyloidosis. Liquid chromatography tandem mass spectrometry did not detect an amino acid sequence abnormality in the transthyretin protein in any of the patients. Five of 6 patients were diagnosed with cardiac amyloidosis, which preceded and followed the diagnosis of prostatic amyloidosis in 1 and 4 patients, respectively. Of these 4 patients, 2 were diagnosed immediately and as a consequence of the diagnosis of prostatic amyloidosis, and the remaining 2 3 and 4 years later. CONCLUSION: Incidental prostatic amyloidosis should prompt systemic and cardiac evaluation for amyloidosis. In patients with suspected cardiac amyloidosis, prior prostate specimens should be reviewed for the presence of amyloidosis.

Patients treated for uric acid stones reoccur more often and within a shorter interval compared to patients treated for calcium stones.

INTRODUCTION: We aimed to investigate the association between stone composition and recurrence rate in a well-characterized group of patients. METHODS: From our prospectively assembled database of 1328 patients undergoing ureteroscopy and percutaneous nephrolithotomy (PCNL) between 2010 and 2015, we identified 457 patients who met the inclusion criteria: a minimum of two years' followup, stone-free status following surgery, normal anatomy, and Fourier transform infrared (FT-IR) stone analysis results. Stone recurrence was identified by kidney-ureter-bladder (KUB) or an ultrasound (US). All symptomatic events were recorded. Kaplan-Meier and Cox proportional hazard regression methods were used to assess the differences in recurrence rates and associated risk factors. RESULTS: Calcium oxalate (CaOx), uric acid (UA), and struvite stones were found in 298 (65.2%), 99 (21.7%), and 28 (6.1%) patients, respectively. During a median followup of 38 months (interquartile range [IQR] 31-48), stone recurred in 111 (24%) patients. One-year stone-free rates (SFRs) stratified by composition were: CaOx 98%, UA 91.9%, calcium phosphate 90%, struvite 88%, and, cystine 83%; the two-year SFRs were 92.6%, 82.7%, 80%, 73%, and 75%, respectively. On multivariate Cox regression analysis, UA composition, the absence of medical preventive therapy, and preoperative stone burden were associated with a shorter time to recurrence. Secondary intervention for recurrent, symptomatic stones was required in 11 (11.1%) and 22 (7.4%) of patients with UA and CaOx stones, respectively (p=0.02). CONCLUSIONS: UA stone-formers are more likely to have a recurrence and to undergo surgical intervention in comparison to CaOx stone-formers, regardless of medical preventive treatment. These differences are more prominent during the first year of followup and should be incorporated into the patient's followup protocol.

Retained Foreign Body Presenting as Pouch Stone After Continent Urinary Diversion.

Background: Continent urinary diversion is a procedure commonly performed in patients after cystectomy who wish to not have a urostomy. Well-documented complications after continent urinary diversion include urinary tract infections and formation of urinary stones. However, these are typically late complications, and few reports have described the onset of these urinary symptoms within 12 months of initial continent urinary diversion. Case Presentation: Herein we report a case of a 41-year-old woman with history of cystectomy with continent urinary diversion who presents with recurrent infections and a calculus in the pouch 10 months after the initial procedure. Upon surgical exploration for removal of the stone, it was discovered that the stone was in fact a calcified retained catheter tip. Conclusion: This case further highlights that stone formation within 12 months of a urinary diversion is unusual and should prompt additional work-up for foreign body.

Prostate cancer and the role of biomarkers.

PURPOSE: To review available prostate cancer biomarkers and their performance in a clinical order, from prostate cancer detection, to treatment of localized and advanced disease. METHODS: We used an electronic literature search of the PubMed database using the key words "prostate biomarkers," "genomic markers," and "prostate cancer screening," as well as specific biomarkers, until March 2019. RESULTS: Prostate-specific antigen (PSA) lacks sensitivity for prostate cancer detection, and PSA derivatives have slightly improved its specificity, but have not resolved the limitations of PSA screening. Prostate cancer biomarkers have emerged as an ancillary tool to guide the clinical decision-making in different clinical scenarios. Urine-based tests can identify patients who may benefit from a prostate biopsy, and issue-based markers are helpful in guiding the decision regarding a second biopsy, stratifying patient with newly diagnosed prostate cancer to active surveillance or treatment, and identifying patients who may benefit from adjuvant treatment after surgery. CONCLUSIONS: New biomarkers have improved risk stratification in diagnosing and treating prostate cancer. Many of these markers are still considered experimental, and their efficacy and cost utility have not been determined.

Tubeless supra-costal percutaneous nephrolithotomy is associated with significantly less hydrothorax: a prospective randomized clinical study.

OBJECTIVES: To evaluate prospectively whether a tubeless (JJ stent-only) percutaneous nephrolithotomy (PCNL) might reduce the risk of hydrothorax, compared to an approach where a nephrostomy tube is left. MATERIALS AND METHODS: We conducted a two-arm open-label prospective randomized study (NCT02036398) comparing tubeless supra-costal PCNL (with a JJ stent only) to standard PCNL (with nephrostomy tube and JJ stent) using intention-to-treat (ITT) and per-protocol (PP) analyses. All patients underwent a standard single-stage prone supra-costal procedure with single-tract access. Complication data were collected according to the Clavien-Dindo grading system. The primary endpoint was the rate of hydrothorax, and secondary endpoints included stone-free rate (SFR) and complication rate. Multivariable logistic regression analysis identified factors associated with hydrothorax formation. RESULTS: Out of 101 patients approached, 75 were finally analysed. No differences were observed between the two arms with regard to baseline demographic and stone characteristics. The mean largest stone size ranged between 23 and 24.2 mm. No significant difference was seen in the mean operating time and length of hospital stay. The incidence of hydrothorax was significantly higher in the nephrostomy group in comparison to the tubeless group (37.8% vs 15.8%, P = 0.031, and 38.4% vs 13.8%, P = 0.016, in the ITT and PP analyses, respectively). The SFR and complication rate were similar in both groups using the ITT and PP analyses. Multivariable logistic regression analysis showed that nephrostomy tube placement was the only covariate associated in a statistically significant manner to hydrothorax (odds ratio 3.628, 95% confidence interval 1.073-12.265; P = 0.038). CONCLUSION: The rate of hydrothorax in supra-costal PCNL is associated with the type of postoperative drainage left. When possible, a tubeless approach should be applied as it may confer a lower risk of hydrothorax.

Predicting the risk of sepsis and causative organisms following urinary stones removal using urinary versus stone and stent cultures.

The association between foreign objects in the urinary system and urinary tract infections (UTI) is well established. The incidence of bacteriuria in patient with urinary catheters increases as dwelling time lengthens. The presence of ureteral stents and kidney stones is also associated with increased risk for bacteriuria and urinary tract infection. The aim of this study was to assess the bacterial characteristics of urine culture (UC) and foreign body culture (FBC), the concordance between them, and to identify risk factors for postoperative infections, in order to improve the treatment in these patients, using a prospectively collected database of patients who underwent ureteroscopy or percutaneous nephrolithotomy (PCNL) for the treatment of urinary stones between 2005 and 2016 at our institute. Preoperative UC was obtained from voided mid-stream urine for all patients. FBCs were obtained from ureteral stents removed and stones collected during the surgery. The cohort included 1011 patients. Mean age was 53 (SD 15.8), and 679 (67.2%) patients were male. Two hundred eighteen (21.6%) had a UTI in the year prior to the surgery. Among 795 patients who had sterile UC, 98 (12.3%) patients had positive FBC. Positive FBC was found in 53.7% of the patients with positive UC; however, FBC pathogens were similar to those identified in UC in 31% patients. The sensitivity of UC to detect FBC pathogens was 31.3%, and the PPV was 0.31. Urine cultures do not recognize all cases of pathogens colonizing foreign bodies in the urinary system. The colonization may be associated with an increased risk for SIRS. In more than one-quarter of the patients, the causative pathogen of sepsis is identified by FBC, but not by UC.