Central Adiposity Increases Risk of Kidney Stone Disease through Effects on Serum Calcium Concentrations.

SIGNIFICANCE STATEMENT: Kidney stone disease is a common disorder with poorly understood pathophysiology. Observational and genetic studies indicate that adiposity is associated with an increased risk of kidney stone disease. However, the relative contribution of general and central adipose depots and the mechanisms by which effects of adiposity on kidney stone disease are mediated have not been defined. Using conventional and genetic epidemiological techniques, we demonstrate that general and central adiposity are independently associated with kidney stone disease. In addition, one mechanism by which central adiposity increases risk of kidney stone disease is by increasing serum calcium concentration. Therapies targeting adipose depots may affect calcium homeostasis and help to prevent kidney stone disease. BACKGROUND: Kidney stone disease affects approximately 10% of individuals in their lifetime and is frequently recurrent. The disease is linked to obesity, but the mechanisms mediating this association are uncertain. METHODS: Associations of adiposity and incident kidney stone disease were assessed in the UK Biobank over a mean of 11.6 years/person. Genome-wide association studies and Mendelian randomization (MR) analyses were undertaken in the UK Biobank, FinnGen, and in meta-analyzed cohorts to identify factors that affect kidney stone disease risk. RESULTS: Observational analyses on UK Biobank data demonstrated that increasing central and general adiposity is independently associated with incident kidney stone formation. Multivariable MR, using meta-analyzed UK Biobank and FinnGen data, established that risk of kidney stone disease increases by approximately 21% per one standard deviation increase in body mass index (BMI, a marker of general adiposity) independent of waist-to-hip ratio (WHR, a marker of central adiposity) and approximately 24% per one standard deviation increase of WHR independent of BMI. Genetic analyses indicate that higher WHR, but not higher BMI, increases risk of kidney stone disease by elevating adjusted serum calcium concentrations (ß=0.12 mmol/L); WHR mediates 12%-15% of its effect on kidney stone risk in this way. CONCLUSIONS: Our study indicates that visceral adipose depots elevate serum calcium concentrations, resulting in increased risk of kidney stone disease. These findings highlight the importance of weight loss in individuals with recurrent kidney stones and suggest that therapies targeting adipose depots may affect calcium homeostasis and contribute to prevention of kidney stone disease.

Impact of COVID-19 on the management and outcomes of ureteric stones in the UK: a multicentre retrospective study.

OBJECTIVES: To determine if management of ureteric stones in the UK changed during the coronavirus disease 2019 (COVID-19) pandemic and whether this affected patient outcomes. PATIENTS AND METHODS: We conducted a multicentre retrospective study of adults with computed tomography-confirmed ureteric stone disease at 39 UK hospitals during a pre-pandemic period (23/3/2019-22/6/2019) and a period during the pandemic (the 3-month period after the first severe acute respiratory syndrome coronavirus-2 case at individual sites). The primary outcome was success of primary treatment modality, defined as no further treatment required for the index ureteric stone. Our study protocol was published prior to data collection. RESULTS: A total of 3735 patients were included (pre-pandemic 1956 patients; pandemic 1779 patients). Stone size was similar between groups (P > 0.05). During the pandemic, patients had lower hospital admission rates (pre-pandemic 54.0% vs pandemic 46.5%, P < 0.001), shorter mean length of stay (4.1 vs 3.3 days, P = 0.02), and higher rates of use of medical expulsive therapy (17.4% vs 25.4%, P < 0.001). In patients who received interventional management (pre-pandemic 787 vs pandemic 685), rates of extracorporeal shockwave lithotripsy (22.7% vs 34.1%, P < 0.001) and nephrostomy were higher (7.1% vs 10.5%, P = 0.03); and rates of ureteroscopy (57.2% vs 47.5%, P < 0.001), stent insertion (68.4% vs 54.6%, P < 0.001), and general anaesthetic (92.2% vs 76.2%, P < 0.001) were lower. There was no difference in success of primary treatment modality between patient cohorts (pre-pandemic 73.8% vs pandemic 76.1%, P = 0.11), nor when patients were stratified by treatment modality or stone size. Rates of operative complications, 30-day mortality, and re-admission and renal function at 6 months did not differ between the data collection periods. CONCLUSIONS: During the COVID-19 pandemic, there were lower admission rates and fewer invasive procedures performed. Despite this, there were no differences in treatment success or outcomes. Our findings indicate that clinicians can safely adopt management strategies developed during the pandemic to treat more patients conservatively and in the community.

Natural history of small asymptomatic kidney and residual stones over a long-term follow-up: systematic review over 25 years.

OBJECTIVE: To systematically review the natural history of small asymptomatic kidney and residual stones, as the incidental identification of small, asymptomatic renal calculi has risen with increasing use of high-resolution imaging. MATERIALS AND METHODS: We reviewed the natural history of small asymptomatic kidney and residual stones using the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology. We searched MEDLINE, Scopus, EMBASE, EBSCO, Cochrane library and Clinicaltrials.gov using themes of 'asymptomatic', 'nephrolithiasis', 'observation', 'symptoms', 'admission', 'intervention' and similar allied terms for all English language articles from 1996 to 2020 (25 years). Inclusion criteria were studies with ≥50 patients, stones ≤10 mm, and a mean follow-up of ≥24 months. Primary outcomes were occurrence of symptoms, emergency admission, and interventions. RESULTS: Our literature search returned 2247 results of which 10 papers were included in the final review. Risk of symptomatic episodes ranged from 0% to 59.4%. Meta-analysis did not identify any significant difference in the likelihood of developing symptoms when comparing stones <5 mm to those >5 mm, nor those <10 mm to those >10 mm. Risk of admission varied from 14% to 19% and the risk of intervention from 12% to 35%. Meta-analysis showed a significantly decreased likelihood of intervention for stones <5 vs >5 mm and <10 vs >10 mm. Studies had variable risk of bias due to heterogeneous reporting of outcome measures with significant likelihood that observed differences in results were compatible with chance alone (Symptoms: I2 =0%, Cochran's Q = 3.09, P = 0.69; Intervention: I2 =0%, Cochran's Q = 1.76, P = 0.88). CONCLUSIONS: The present systematic review indicates that stone size is not a reliable predictor of symptoms; however, risk of intervention is greater for stones >5mm vs <5 mm and >10 vs <10 mm. This review will inform urologists as they discuss management strategies with patients who have asymptomatic renal stones and offer insight to committees during the development of evidence-based guidelines.

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.

Local anaesthetic transperineal (LATP) prostate biopsy using a probe-mounted transperineal access system: a multicentre prospective outcome analysis.

OBJECTIVES: To assess the feasibility of local anaesthetic transperineal (LATP) technique using a single-freehand transperineal (TP) access device, and report initial prostate cancer (PCa) detection, infection rates, and tolerability. PATIENTS AND METHODS: Observational study of a multicentre prospective cohort, including all consecutive cases. LATP was performed in three settings: (i) first biopsy in suspected PCa, (ii) confirmatory biopsies for active surveillance, and (iii) repeat biopsy in suspected PCa. All patients received pre-procedure antibiotics according to local hospital guidelines. Local anaesthesia was achieved by perineal skin infiltration and periprostatic nerve block without sedation. Ginsburg protocol principles were followed for systematic biopsies including cognitive magnetic resonance imaging-targeted biopsies when needed using the PrecisionPoint™ TP access device. Procedure-related complications and oncological outcomes were prospectively and consecutively collected. A validated questionnaire was used in a subset of centres to collect data on patient-reported outcome measures (PROMs). RESULTS: Some 1218 patients underwent LATP biopsies at 10 centres: 55%, 24%, and 21% for each of the three settings, respectively. Any grade PCa was diagnosed in 816 patients (67%), of which 634 (52% of total) had clinically significant disease. Two cases of sepsis were documented (0.16%) and urinary retention was observed in 19 patients (1.6%). PROMs were distributed to 419 patients, with a 56% response rate (n = 234). In these men, pain during the biopsy was described as either 'not at all' or 'a little' painful by 64% of patients. Haematuria was the most common reported symptom (77%). When exploring attitude to re-biopsy, 48% said it would be 'not a problem' and in contrast 8.1% would consider it a 'major problem'. Most of the patients (81%) described the biopsy as a 'minor or moderate procedure tolerable under local anaesthesia', while 5.6% perceived it as a 'major procedure that requires general anaesthesia'. CONCLUSION: Our data suggest that LATP biopsy using a TP access system mounted to the ultrasound probe achieves excellent PCa detection, with a very low sepsis rate, and is safe and well tolerated. We believe a randomised controlled trial comparing LATP with transrectal ultrasound-guided biopsy (TRUS) to investigate the relative trade-offs between each biopsy technique would be helpful.

Comparison of Transrectal Ultrasound Biopsy to Transperineal Template Mapping Biopsies Stratified by Multiparametric Magnetic Resonance Imaging Score in the PROMIS Trial.

PURPOSE: We evaluated the performance of transrectal ultrasound guided systematic and transperineal template mapping biopsies with a 5 mm sampling frame stratified by the multiparametric magnetic resonance imaging Likert score in the PROMIS (Prostate MR Imaging Study). MATERIALS AND METHODS: Biopsy naïve men due to undergo prostate biopsy for elevated prostate specific antigen and/or abnormal digital rectal examination underwent multiparametric magnetic resonance imaging, and transperineal template mapping and transrectal ultrasound guided systematic biopsies, which were performed and reported while blinded to other test results. Clinically significant prostate cancer was primarily defined as Gleason 4 + 3 or greater, or a maximum cancer core length of 6 mm or more of any grade. It was secondarily defined as Gleason 3 + 4 or greater, or a maximum cancer core length of 4 mm or more of any grade. RESULTS: In 41 months 740 men were recruited at a total of 11 centers, of whom 576 underwent all 3 tests. Eight of the 150 men (5.1%) with a multiparametric magnetic resonance imaging score of 1-2 had any Gleason 3 + 4 or greater disease on transrectal ultrasound guided systematic biopsy. Of the 75 men in whom transrectal ultrasound guided systematic biopsy showed Gleason 3 + 3 of any maximum cancer core length 61 (81%) had Gleason 3 + 4, 8 (11%) had Gleason 4 + 3 and 0 (0%) had Gleason 4 + 5 or greater disease. For definition 1 (clinically significant prostate cancer) transrectal ultrasound guided systematic biopsy sensitivity remained stable and low across multiparametric magnetic resonance imaging Likert scores of 35% to 52%. For definition 2 (clinically significant prostate cancer and any cancer) sensitivity increased with higher multiparametric magnetic resonance imaging scores. The negative predictive value varied due to varying disease prevalence but for all cancer thresholds it declined with increasing multiparametric magnetic resonance imaging scores. CONCLUSIONS: In the setting of multiparametric magnetic resonance imaging Likert scores 1-2 transrectal ultrasound guided systematic biopsy revealed Gleason 3 + 4 disease in only 1 of 20 men. Further, for any clinically significant prostate cancer definition transrectal ultrasound guided systematic biopsy had poor sensitivity and variable but a low negative predictive value across multiparametric magnetic resonance imaging scores. Men who undergo transrectal ultrasound guided systematic biopsy without targeting in the setting of a multiparametric magnetic resonance imaging score of 3 to 5 should be advised to undergo repeat (targeted) biopsy.

Evaluation of functional outcomes after a second focal high-intensity focused ultrasonography (HIFU) procedure in men with primary localized, non-metastatic prostate cancer: results from the HIFU Evaluation and Assessment of Treatment (HEAT) registry.

OBJECTIVES: To assess change in functional outcomes after a second focal high-intensity focused ultrasonography (HIFU) treatment compared with outcomes after one focal HIFU treatment. PATIENTS AND METHODS: In this multicentre study (2005-2016), 821 men underwent focal HIFU for localized non-metastatic prostate cancer. The patient-reported outcome measures of International Prostate Symptom Score (IPSS), pad usage and erectile function (EF) score were prospectively collected for up to 3 years. To be included in the study, completion of at least one follow-up questionnaire was required. The primary outcome was comparison of change in functional outcomes between baseline and follow-up after one focal HIFU procedure vs after a second focal HIFU procedure, using IPSS, Expanded Prostate Cancer Index Composite (EPIC) and International Index of Erectile Function (IIEF) questionnaires. RESULTS: Of 821 men, 654 underwent one focal HIFU procedure and 167 underwent a second focal HIFU procedure. A total of 355 (54.3%) men undergoing one focal HIFU procedure and 65 (38.9%) with a second focal HIFU procedure returned follow-up questionnaires, respectively. The mean age and prostate-specific antigen level were 66.4 and 65.6 years, and 7.9 and 8.4 ng/mL, respectively. After one focal HIFU treatment, the mean change in IPSS was -0.03 (P = 0.02) and in IIEF (EF score) it was -0.4 (P = 0.02) at 1-2 years, with no subsequent decline. Absolute rates of erectile dysfunction increased from 9.9% to 20.8% (P = 0.08), leak-free continence decreased from 77.9% to 72.8% (P = 0.06) and pad-free continence from 98.6% to 94.8% (P = 0.07) at 1-2 years, respectively. IPSS prior to second focal HIFU treatment compared to baseline IPSS prior to first focal HIFU treatment was lower by -1.3 (P = 0.02), but mean IPSS change was +1.4 at 1-2 years (P = 0.03) and +1.2 at 2-3 years (P = 0.003) after the second focal HIFU treatment. The mean change in EF score after the second focal HIFU treatment was -0.2 at 1-2 years (P = 0.60) and -0.5 at 2-3 years (P = 0.10), with 17.8% and 6.2% of men with new erectile dysfunction. The rate of new pad use was 1.8% at 1-2 years and 2.6% at 2-3 years. CONCLUSION: A second focal HIFU procedure causes minor detrimental effects on urinary function and EF. These data can be used to counsel patients with non-metastatic prostate cancer prior to considering HIFU therapy.

Sexual function outcomes following interventions for prostate cancer: are contemporary reports on functional outcomes misleading?

Patients with primary localised prostate cancer (PCa) have a wide choice of curative therapeutic interventions, including active surveillance, surgical, focal and radiation therapies. Based on clinical and oncological characteristics, treatment decisions entail consideration of oncological and functional outcomes with important effects on quality of life. We aimed to highlight evidence surrounding present inconsistencies, the problems this presents to clinicians and patients alike and the rationale for using return to baseline as a more realistic and objective functional outcome measure for assessing sexual function in this particularly sensitive group of men. We performed a non-systematic literature review of numerous non-validated, arbitrary thresholds employed in evaluation of sexual function outcomes in men undergoing intervention for primary localised PCa. The literature presents much heterogeneity in measurement methods and outcome measures, which lack context and present difficulties when counselling patients to make informed, autonomous decisions. These include findings from the most widely used internationally validated tools, such as the International Index of Erectile Function (IIEF), UCLA prostate cancer index and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 (QLQ-C30). There is a need for standardisation of reporting outcomes following PCa treatment to facilitate evaluation of existing and emerging technologies.

Simulation training in upper tract endourology: myth or reality?

Surgeons training in the twenty-first century are subject to a myriad of pressures, as has always been the case within surgical training. These include reduced hours available for training and increased threat of litigation against their operating practice. The Halstedian approach of "see one, do one, teach one" has been replaced within surgical training and simulation has become established to enable urology trainees to develop technical and non-technical skills away from the operating room. With the primary focus as patient safety and increasing operating skill, "simulation training" encompasses several modalities. These include wet-lab cadaveric and animal models, dry lab, high fidelity, low-fidelity and virtual reality (VR). These can be used to practice generic surgical skills, such as laparoscopic suturing or knot tying on a robotic console. Beyond this there is potential for simulation training courses and full-immersion simulation to address non-technical skills and team aspects within the operating room. To incorporate simulators into training, models must be carefully designed and evaluated according to certain considerations, ensuring that they address parameters such as face, content and construct validity. This review aimed to provide an overview of simulation platforms available within endourology, considering ureterorenoscopy and percutaneous nephrolithotomy and the status of their validation.