Prospective Multicenter Evaluation of Pain Before and After Removal of Nonobstructing Renal Calculi: A CoRE Initiative.

PURPOSE: Flank pain associated with stone disease is typically caused by a stone that obstructs urine flow. However, it is plausible that nonobstructing kidney stones may still cause pain. We performed a multicenter, observational trial to evaluate whether treatment of small nonobstructing calyceal stones improves pain and kidney stone-specific health-related quality of life. MATERIALS AND METHODS: Patients aged 18 years or older with nonobstructing renal stone(s) up to 10 mm in longest diameter and moderate to severe pain were recruited. All participants completed 3 questionnaires: the Brief Pain Inventory (BPI), the Patient-Reported Outcomes Measurement Information System pain interference form 6a, and the Wisconsin Stone Quality of Life questionnaire. Thereafter, all participants underwent ureteroscopy for renal stone treatment. All 3 questionnaires were repeated at 2, 6 to 8, and at 12 weeks postprocedure. The primary outcomes were change in preoperative to 12-week postoperative mean BPI score and worst BPI pain score. RESULTS: A total of 43 patients with nonobstructing kidney stones and associated flank pain were recruited. All stones were removed. Preoperatively, BPI scores for mean pain and worst pain were 5.5 and 7.2, respectively which decreased to 1.8 and 2.8 respectively at 12 weeks postoperatively. Wisconsin Stone Quality of Life questionnaire mean score increased from 70.4 to 115.3 at 12 weeks postoperatively. A total of 86% and 69% of patients had at least a 20% and 50% reduction in their mean pain scores, respectively. CONCLUSIONS: This study determined that patients benefit significantly from the removal of calyceal nonobstructing kidney stones for at least 12 weeks with a reduction in pain and an increase in quality of life. Therefore, surgical removal of these stones in this patient population should be offered as a treatment option.

Redlining has led to increasing rates of nephrolithiasis in minoritized populations: a hypothesis.

PURPOSE OF REVIEW: The persistent rise in kidney stone prevalence in recent decades has prompted much speculation as to the causes. There has been some discussion about the effect of heat on nephrolithiasis. Here, we review recent data and postulate that heat may play a role in stone formation on a large scale and among African-Americans in particular. RECENT FINDINGS: African-Americans are the race/ancestry group with faster rates of increasing incidence and prevalence of kidney stones. We make the observation that urban heat islands in the United States have resulted in part from the effects of redlining, a practice of systematic segregation and racism in housing that led to the development of neighborhoods with substantial disparities in environmental conditions. SUMMARY: In this thought experiment, we propose that the disproportionate rise in the prevalence of nephrolithiasis in minoritized populations correlates with increased temperatures specifically in neighborhoods adversely affected by the practice of redlining. We discuss phenomena in support of this hypothesis and ongoing work to test this theory.

Indwelling stents cause obstruction and induce ureteral injury and fibrosis in a porcine model.

OBJECTIVES: To investigate global changes in ureters at the transcriptional, translational and functional levels, both while stents are indwelling and after removal and recovery, and to study the effects of targeting pathways that play a potential role. METHODS: Pig ureters were stented for varying amounts of time (48 h, 72 h, 14 days) and the impact on peristalsis, dilatation and hydronephrosis were assessed. RNAseq, proteomic, histological and smooth muscle (SM) function analyses were performed on ureteric and kidney tissues to assess changes induced by stenting and recovery. Pathway analysis was performed using Ingenuity Pathway Analysis software. To study the impact of possible interventions, the effects of erythropoeitin (EPO) and a Gli1 inhibitor were assessed. RESULTS: Stenting triggers massive ureteric dilatation, aperistalsis and moderate hydronephrosis within 48 h. Pathways associated with obstruction, fibrosis and kidney injury were upregulated by stenting. Increased expression of GLI1, clusterin-α (a kidney injury marker) and collagen 4A2 (a fibrosis marker) was found in stented vs contralateral unstented ureters. EPO did not improve peristalsis or contraction force but did decrease non-purposeful spasming seen exclusively in stented ureters. Tamsulosin administration increased contractility but not rate of peristalsis in stented ureters. CONCLUSIONS: Ureters respond to stents similarly to how they respond to an obstruction, that is, with activation of pathways associated with hydronephrosis, fibrosis and kidney injury. This is driven by significant dilatation and associated ureteric SM dysfunction. EPO and tamsulosin induced mild favourable changes in SM physiology, suggesting that targeting specific pathways has potential to address stent-induced complications.

The Uniform grading tooL for flexIble ureterorenoscoPes (TULIP-tool): a Delphi consensus project on standardised evaluation of flexible ureterorenoscopes.

OBJECTIVE: To develop a standardised tool to evaluate flexible ureterorenoscopes (fURS). MATERIALS AND METHODS: A three-stage consensus building approach based on the modified Delphi technique was performed under guidance of a steering group. First, scope- and user-related parameters used to evaluate fURS were identified through a systematic scoping review. Then, the main categories and subcategories were defined, and the expert panel was selected. Finally, a two-step modified Delphi consensus project was conducted to firstly obtain consensus on the relevance and exact definition of each (sub)category necessary to evaluate fURS, and secondly on the evaluation method (setting, used tools and unit of outcome) of those (sub)categories. Consensus was reached at a predefined threshold of 80% high agreement. RESULTS: The panel consisted of 30 experts in the field of endourology. The first step of the modified Delphi consensus project consisted of two questionnaires with a response rate of 97% (n = 29) for both. Consensus was reached for the relevance and definition of six main categories and 12 subcategories. The second step consisted of three questionnaires (response rate of 90%, 97% and 100%, respectively). Consensus was reached on the method of measurement for all (sub)categories. CONCLUSION: This modified Delphi consensus project reached consensus on a standardised grading tool for the evaluation of fURS - The Uniform grading tooL for flexIble ureterorenoscoPes (TULIP) tool. This is a first step in creating uniformity in this field of research to facilitate future comparison of outcomes of the functionality and handling of fURS.

Migration time correction for dual pressure capillary electrophoresis in semi-targeted metabolomics study.

Migration time fluctuation strongly affects peak alignment and identification of unknown compounds, making migration time correction an essential step in capillary electrophoresis (CE)-based metabolomics. To obtain more reliable information, metabolites with different apparent mobilities are analyzed by tandem mass spectrometry. Applying a small pressure is a common practice for reducing the analysis time of anions in a positive mode CE, known as the pressure-assisted CE. However, applying pressure may reduce the separation efficiency and can be undesirable for cation analysis. A simple way to address this issue is to increase the pressure after a certain time, during the separation. We term this practice as dual pressure CE. However, changing the pressure during the CE separation complicates migration time correction. Previous migration time correction methods were established based on a consistent electroosmotic flow and a constant pressure-driven bulk-flow velocity. We proposed a new correction method to support the peak alignment when dual pressure CE is used. A Python-based script was developed to implement dual pressure CE migration time correction for semi-targeted metabolomics study performed by a multiple reaction monitoring-based method. This script can help select suitable endogenous metabolites as correction markers, perform migration time correction, and conduct peak alignment. A case study showed that migration time precision of 156 metabolites in 32 samples can be improved from 4.8 to 11.4%RSD (relative standard deviation) to less than 1.8%RSD.

Stone disease in low- and middle-income countries: could augmented reality have a role in its management?

Urolithiasis is a global phenomenon. Cystolithiasis is common in parts of Africa due to low protein intake and dehydration from endemic diarrhoeal illnesses. Nephrolithiasis is less prevalent than in high-income countries, probably due to a variety of lifestyle issues, such as a more elemental diet, higher physical activity, and less obesity. Although renal stones are less common in low- and middle-income countries (LMICs), the social and economic impacts of nephrolithiasis are still considerable; many stones present late or with complications such as upper urinary tract obstruction or urosepsis. These may lead to the development of chronic kidney disease, or end-stage renal failure in a small proportion of cases, conditions for which there is very poor provision in most LMICs. Early treatment of nephrolithiasis by the least invasive method possible can, however, reduce the functional consequences of urinary stone disease. Although extracorporeal lithotripsy is uncommon, and endoscopic interventions for stone are not widespread in most of Africa, percutaneous nephrolithotomy and ureteroscopic renal surgery are viable techniques in those regional centres with infrastructure to support them. Longitudinal mentoring has been shown to be a key step in the adoption of these minimally invasive procedures by local surgeons, something that has been difficult during the coronavirus disease 2019 (COVID-19) pandemic due to travel restriction. Augmented reality (AR) technology is an alternative means of providing remote mentoring, something that has been trialled by Urolink, the MediTech Trust and other global non-governmental organisations during this period. Our preliminary experience suggests that this is a viable technique for promulgating skills in LMICs where appropriate connectivity exists to support remote communication. AR may also have long-term promise for decreasing the reliance upon short-term surgical visits to consolidate competence, thereby reducing the carbon footprint of global surgical education.

Prospective randomized trial of 2 versus 12-weeks of postoperative antibiotics after percutaneous nephrolithotomy in complex patients with infection-related kidney stones.

PURPOSE: Treatment of struvite kidney stones requires complete surgical stone removal combined with antibiotic therapy to eliminate urinary tract infections and preventive measures to reduce stone recurrence. The optimal duration of antibiotic therapy is unknown. We sought to determine if 2- or 12-weeks of antibiotics post percutaneous nephrolithotomy (PNL) for infection stones resulted in better outcomes for stone recurrence and positive urine cultures. MATERIAL AND METHODS: This multi-center, prospective randomized trial evaluated patients with the clinical diagnosis of infection stones. Patients were randomized to 2- or 12-weeks of postoperative oral antibiotics (nitrofurantoin or culture-specific antibiotic) and included if residual fragments were ≤4 mm on computed tomography imaging after PNL. Imaging and urine analyses were performed at 3-, 6-, and 12-months post-procedure. RESULTS: Thirty-eight patients were enrolled and randomized to either 2-weeks (n = 20) or 12-weeks (n = 18) of antibiotic therapy post-PNL. Eleven patients were excluded due to residual fragments >4 mm, and 3 patients were lost to follow-up. The primary outcome was the stone-free rate (SFR) at 6 months post-PNL. At 3-, 6-, and 12-months follow-up, SFRs were 72.7% versus 80.0%, 70.0% versus 57.1%, 80.0% versus 57.1% (p = ns), between 2- and 12-week-groups, respectively. At 3-, 6-, and 12-months follow-up, positive urine cultures were 50.0% versus 37.5%, 50.0% versus 83.3%, and 37.5% versus 100% between 2- and 12-week groups, respectively (p = ns). CONCLUSIONS: For patients with stone removal following PNL, neither 2-weeks nor 12-weeks of postoperative oral antibiotics is superior to prevent stones and recurrent positive urine cultures.

Stent duration and increased pain in the hours after ureteral stent removal.

INTRODUCTION To assess the relationship between pain after ureteral stent removal and patient and procedural factors. MATERIALS AND METHODS: A validated survey designed to assess the relationship between quality of life and treatment decisions in kidney stone disease was randomly distributed to patients with a history of a ureteral stent in seven medical centers across North America participating in an endourology research collaborative between July 2016 and June 2018. The primary outcome was increased pain after ureteral stent removal. Statistical analyses were performed using Chi-square and multiple logistic regression. RESULTS: A total of 327 surveys were analyzed. Twenty seven percent of patients reported increased pain in the hours after ureteral stent removal. Patients with a stent ≤ 7 days were significantly more likely to experience pain after stent removal compared to those with a stent > 7 days (33.3% versus 22.8%, p = 0.04). Female gender (OR: 2.41, 95% CI: 1.42-4.10) was associated with increased pain after stent removal, while increasing age was inversely associated (OR: 0.52, 95% CI: 0.36-0.74). After adjustment, patients with a stent > 7 days were significantly less likely to report pain in the hours after removal (OR: 0.59, 95% CI: 0.35-0.99). CONCLUSIONS: Approximately one in four patients will experience increased pain after ureteral stent removal. Female patients, younger patients, and patients with a stent ≤ 7 days were more likely to experience an increase in pain immediately following stent removal. Understanding factors associated with post-stent removal pain may be helpful in counseling patients at high risk stent removal morbidity.

Application of multisegment injection on quantification of creatinine and standard addition analysis of urinary 5-hydroxyindoleacetic acid simultaneously with creatinine normalization.

In this paper, the development of a simple dilute-and-shoot method for quantifying urinary creatinine by CE-ESI-MS was described. The creatinine analysis time was about 7 min/sample by conventional single injection (SI) method and can be significantly reduced to less than 2 min/sample with multi-segment injection (MSI). In addition, the standard addition analysis of 5-hydroxyindole-3-acetic acid (5-HIAA) and creatinine normalization was performed within one run by the MSI technique, and the total analysis time was 14-min faster compared to the SI method for analyzing the same set of samples. The uses of isotopic and non-isotopic internal standards (ISs) were compared. Creatinine-(methyl-13 C) and 5-hydroxyindole-4,6,7-D3 -3-acetic-D2 acid (5-HIAA-D5 ) used as isotopic ISs can provide both accurate and precise results. In contrast, 1,5,5-trimethylhydantoin (1,5,5-TH) used as the non-isotopic IS for creatinine may cause a bias of over 13% in SI method and even worse when the MSI technique was used. Another compound, 2-methyl-3-indoleacetic acid (2-MIAA), was determined not suitable for MSI analysis of 5-HIAA due to endogenous interferences despite its acceptable performance in conventional methods of analysis.

Ureteral stent-associated infection and sepsis: pathogenesis and prevention: a review.

Ureteral stents are commonly used devices in hospital settings. However, their usage is often complicated by associated urinary tract infections as a result of bacterial adhesion onto the indwelling implant surfaces, followed by the formation of layers of biofilm. Once formed, the biofilm is exceedingly difficult to remove, potentially leading to further morbidity and even urosepsis. Urosepsis, where pathogens from the urinary tract enter the bloodstream, has a mortality rate of up to 50% of severely infected patients. Hence, it is important to understand its pathogenesis. In this review, ureteral stent-associated urinary tract infection and urosepsis will be addressed. In particular, the bacterial mechanisms involved, as well as the prevention and treatment of these infections will be discussed.

Conversion from Cystine to Noncystine Stones: Incidence and Associated Factors.

PURPOSE: Patients with cystinuria are often treated with medical alkalization and shock wave lithotripsy, although each treatment is hypothesized to increase the risk of calcium phosphate stones. We performed a multicenter retrospective review to evaluate whether stones of another composition develop in patients with cystinuria and with what frequency. MATERIALS AND METHODS: We retrospectively reviewed the records of a multi-institutional cohort of patients with cystinuria. We assessed medications, stone analyses, 24-hour urinalyses and types of procedures. We compared patients who formed only cystine stones vs those with noncystine stones. RESULTS: We identified 125 patients from a total of 5 institutions who were followed a mean of 5.2 years (range 0 to 26). Stones with noncystine components were submitted by 37 patients (29.6%). Potassium citrate medication was not associated with a noncystine composition (p = 0.1877). Regarding surgical management 18 patients (13%) underwent at least 1 shock wave lithotripsy session (range 0 to 9) and 79 (63%) underwent percutaneous nephrolithotomy at least once (range 0 to 10). When stratified based on pure cystine vs converted stones, the average total number of shock wave lithotripsy and percutaneous nephrolithotomy procedures was higher in the group with cystine and subsequent noncystine stone compositions (0.94 vs 0.10, p <0.0001, and 1.7 vs 1.5, p = 0.0053, respectively). On logistic regression male gender (OR 3.1, p = 0.0280) and the number of shock wave lithotripsy sessions (OR 3.0, p = 0.0170) were associated with an increased likelihood of the development of stones with a noncystine composition. CONCLUSIONS: Stones with noncystine components develop in more than 25% of patients with cystinuria, underscoring the importance of continued stone analysis. In this study prior shock wave lithotripsy was associated with conversion to a noncystine stone composition while urinary alkalization therapy was not associated.

Shockwave lithotripsy: techniques for improving outcomes.

OBJECTIVES: Shock wave lithotripsy (SWL) remains the only effective truly non-invasive treatment for nephrolithiasis. While single-treatment success rates may not equal those of ureteroscopy and percutaneous nephrolithotomy, it has an important role to play in the management of stones. In this paper, we outline the latest evidence-based recommendations for maximizing SWL outcomes, while minimizing complications. MATERIALS AND METHODS: A comprehensive review of the current literature was performed regarding maximizing SWL outcomes. RESULTS: Several different considerations need to be made regarding patient selection with respect to body habitus, body mass index, anatomical location and underlying urologic abnormalities. Stone composition and stone density (Hounsfield Units) are important prognostic variables. Patient positioning is critical to allow for adequate stone localization with either fluoroscopy or ultrasound. Coupling should be optimized with a low viscosity gel applied to the therapy head first and patient movement should be limited. SWL energy should be increased slowly and shockwave rates of 60 or 90 Hz should be used. Medical expulsive therapy with alpha-blockers after SWL treatment has shown benefit, particularly with stones greater than 10 mm. CONCLUSION: While single-treatment success rates may not equal those of ureteroscopy or percutaneous nephrolithotomy, with proper patient selection, optimization of SWL technique, and use of adjunctive treatment after SWL, success rates can be maximized while further reducing the already low rate of serious complications. SWL remains an excellent treatment option for calculi even in 2017.

Stone technology: intracorporeal lithotripters.

PURPOSE: Intracorporeal lithotripsy is becoming the most commonly used surgical method of stone treatment in Urology. The five major types of intracorporeal lithotripters are ultrasonic, ballistic, and combination lithotripters as well as laser and electrohydraulic lithotripters. The advantages and disadvantages of choosing each of these treatment modalities are reviewed. METHODS: Extensive review of literature was performed to identify the types of intracorporeal lithotripters. An investigation was undertaken of the early development of each modality of intracorporeal lithotripsy and/or the mechanism of action. Challenges of each technique were identified and presented. Finally, a determination was made of how these lithotripters compare on the basis of effectiveness of action and cost based on information provided in primary literature as well as previous reviews of these modalities. RESULTS: Contemporary lithotripters have found widespread use in the management of urinary lithiasis. Holmium laser lithotripsy has become one of the most commonly used tools for intracorporeal lithotripsy. CONCLUSION: There is a wide variety of intracorporeal lithotripters which can be chosen based on the characteristics of each modality and the requirements of the urologist.

Risk factors for biochemical recurrence after robotic assisted radical prostatectomy: a single surgeon experience.

BACKGROUND: Radical prostatectomy is a standard surgical treatment of clinically localized prostate cancer. Margin status has been found to be an independent predictor of biochemical recurrence (BCR) after open radical prostatectomy in several large series but this is still controversy in Robotic Assisted Radical Prostatectomy (RARP) series. We therefore wanted to investigate the prognostic significance of positive surgical margin (PSM) and other pathological factors on BCR in patients treated with RARP by a single surgeon. METHODS: Prospectively collected data of 439 patients treated with RARP between October 2005 and June 2013 by a single surgeon at a single institution were analyzed. BCR was defined as follow-up PSA level > 0.2 ng/ml on two separate occasions or patients who had to undergo salvage therapy. Kaplan Meier curves and Log Rank test were used to compare the risk of BCR. Univariate and Multivariate Cox Regression analyses were performed to determine the prognostic impact of age, BMI, prostate weight, PSA prior to surgery, pathological T-stage, pathological Gleason sum, PSM and operative period. RESULTS: In this study period, 34 out of 439 had BCR, giving an overall BCR rate of 7.7% for this cohort. Overall 2- and 3-year BCR-free survival rates were 93% and 88%, respectively. Patients with a PSM had a 2-year BCR free survival of 88% compared to 94% in those with negative margins (p < .0001). On the multivariate analysis, PSM as well as pathological Gleason sum > = 8, PSA, pathological stage and operative period were significantly associated with BCR. CONCLUSIONS: In our case series of RARP performed by a single surgeon, PSM as well as pathological Gleason sum, PSA, pathological stage and early operative period for this surgeon were the independent predictors of BCR.

Evaluation of augmented reality technology in global urologic surgery.

BACKGROUND: The COVID-19 pandemic drastically reduced opportunities for surgical skill sharing between high-income and low to middle-income countries. Augmented reality (AR) technology allows mentors in one country to virtually train a mentee in another country during surgical cases without international travel. We hypothesize that AR technology is an effective live surgical training and mentorship modality. METHODS: Three senior urologic surgeons in the US and UK worked with four urologic surgeon trainees across the continent of Africa using AR systems. Trainers and trainees individually completed post-operative questionnaires evaluating their experience. RESULTS: Trainees rated the quality of virtual training as equivalent to in-person training in 83% of cases (N = 5 of 6 responses). Trainers reported the technology's visual quality as "acceptable" in 67% of cases (N = 12 of 18 responses). The audiovisual capabilities of the technology had a "high" impact in the majority of the cases. CONCLUSION: AR technology can effectively facilitate surgical training when in-person training is limited or unavailable.

Social Determinants of Kidney Stone Disease: The Impact of Race, Income and Access on Urolithiasis Treatment and Outcomes.

The medical and surgical management of kidney stones is one of the most common functions of the urologist. Management choices are often nuanced, involving the decision to embark on one surgical plan among several options. As the wider medical community critically evaluates the care we provide to an increasingly diverse population, it will be important to examine patient outcomes with a particular focus on ensuring equitable care. This review examines the influence of social parameters on the care of kidney stone patients. The dearth of literature in this area warrants rigorous studies on the relationship between race as well as socioeconomic status and the management of kidney stone disease.

Online Engagement with Surgical Treatments for Benign Prostatic Hyperplasia: Are Minimally Invasive Surgical Therapies Outpacing the Gold Standard?

Background: Patients suffering from progressive symptoms of benign prostatic hyperplasia (BPH) increasingly turn to the internet for information on invasive and minimally invasive surgical therapies (MIST). This study aimed to identify online articles accessed by patients seeking guidance on said options and to evaluate the quality and readability of their content. Methods: Social media analytics tool Buzzumo was used to identify the most shared articles on Facebook, Twitter, Reddit, and Pinterest related to BPH surgical treatments from 2016 to 2021. The content quality was graded using the DISCERN tool; a questionnaire that assesses the quality of written information on treatment choices for a health problem. An online Automatic Readability Checker was used to evaluate the readability of the written transcripts. Google Trends data were used to evaluate search term popularity for BPH procedures from 2016 to 2021. Google Trends data and DISCERN ratings were analyzed with ANOVA and paired t-test, respectively. Results: Thirty-nine percent of identified articles were rated as low quality, 39% as moderate quality, and 22% as high quality using the DISCERN tool, with no significant difference among reviewer ratings (p = 0.0561). The median reading level of all articles was 12th grade. Google Trends data illustrated a rising popularity of MIST such as Rezum and urethral lift (Urolift), exceeding interest in more invasive procedures such as Holmium laser enucleation of the prostate (HoLEP) and laser surgery. Transurethral resection of the prostate (TURP) remained popular with no significant difference between MIST and TURP on Google Trends (p = 3.46). Conclusions: The most accessed articles on BPH treatments have important shortcomings, including risks of treatment and other available options for treatment. Article transcripts exceed the reading level of the average adult patient. TURP has remained a popular procedure online, but there is a notable rising interest in MIST, especially Urolift.

Consensus Statement on Urinary Stone Treatment During a Pandemic: A Delphi Process from the Endourological Society TOWER Research Initiative.

Introduction: The novel coronavirus disease (COVID-19) pandemic has had a significant impact on the care of patients with urolithiasis. Recommendations and prioritization of endourologic surgical procedures vary among regions, and a comprehensive overall international directive is needed. We used the Delphi method to obtain international consensus on managing urolithiasis patients during the pandemic. Methods: A three-round Delphi process was used to elicit expert consensus (53 global key opinion leaders within the Endourological Society from 36 countries) on an extensive survey on management of endourologic patients in a pandemic. Questions addressed general management, inpatient and outpatient procedures, clinic visits, follow-up care, and best practices for suspension and resumption of routine care. Results: Consensus was achieved in 64/84 (76%) questions. Key consensus findings included the following: consultations should be delivered remotely when possible. Invasive surgical procedures for urolithiasis patients should be reserved for high-risk situations (infection, renal failure, etc.). To prevent aerosolization, spinal anesthesia is preferred over general, whenever feasible. Treatment of asymptomatic renal stones should be deferred. Primary definitive treatment of obstructing or symptomatic stones (both renal and ureteral) is preferred over temporizing drainage. Extracorporeal shockwave lithotripsy should be continued for obstructive ureteral stones. There was consensus on treatment modalities and drainage strategies depending on location and size of the stone. Conclusion: International endourologist members of the Endourological Society participated in this Delphi initiative to provide expert consensus on management of urolithiasis during a pandemic. These results can be applied currently and during a future pandemic.