What is the definition of stone dust and how does it compare with clinically insignificant residual fragments? A comprehensive review.

PURPOSE: During endoscopic stone surgery, Holmium:YAG (Ho:YAG) and Thulium Fiber Laser (TFL) technologies allow to pulverize urinary stones into fine particles, ie DUST. Yet, currently there is no consensus on the exact definition of DUST. This review aimed to define stone DUST and Clinically Insignificant Residual Fragments (CIRF). METHODS: Embase, MEDLINE (PubMed) and Cochrane databases were searched for both in vitro and in vivo articles relating to DUST and CIRF definitions, in November 2023, using keyword combinations: "dust", "stones", "urinary calculi", "urolithiasis", "residual fragments", "dusting", "fragments", "lasers" and "clinical insignificant residual fragments". RESULTS: DUST relates to the fine pulverization of urinary stones, defined in vitro as particles spontaneously floating with a sedimentation duration ≥ 2 sec and suited for aspiration through a 3.6Fr-working channel (WC) of a flexible ureteroscope (FURS). Generally, an upper size limit of 250 µm seems to agree with the definition of DUST. Ho:YAG with and without "Moses Technology", TFL and the recent pulsed-Thulium:YAG (pTm:YAG) can produce DUST, but no perioperative technology can currently measure DUST size. The TFL and pTm:YAG achieve better dusting compared to Ho:YAG. CIRF relates to residual fragments (RF) that are not associated with imminent stone-related events: loin pain, acute renal colic, medical or interventional retreatment. CIRF size definition has decreased from older studies based on Shock Wave Lithotripsy (SWL) (≤ 4 mm) to more recent studies based on FURS (≤ 2 mm) and Percutaneous Nephrolithotomy(PCNL) (≤ 4 mm). RF ≤ 2 mm are associated with lower stone recurrence, regrowth and clinical events rates. While CIRF should be evaluated postoperatively using Non-Contrast Computed Tomography(NCCT), there is no consensus on the best diagnostic modality to assess the presence and quantity of DUST. CONCLUSION: DUST and CIRF refer to independent entities. DUST is defined in vitro by a stone particle size criteria of 250 µm, translating clinically as particles able to be fully aspirated through a 3.6Fr-WC without blockage. CIRF relates to ≤ 2 RF on postoperative NCCT.

Percutaneous Nephrolithotomy for De Novo Urolithiasis After Kidney Transplantation: A Systematic Review of the Literature.

Introduction and Objective: Renal transplantation is the treatment for end-stage renal disease that offers better quality of life and survival. Among the possible complications that might affect allografts, urolithiasis might have severe consequences, causing acute kidney injury (AKI) or septic events in immunocompromised patients. Allograft stones might be treated with percutaneous nephrolithotomy (PCNL). The aim of this Cochrane style review was to assess the safety and efficacy of PCNL in patients with renal transplant. Methods: A comprehensive search in the literature was performed including articles between July 1982 and June 2023, with only English original articles selected for this review. Results: The final review encompassed nine articles (108 patients). The mean age was 46.4 ± 8.7 years, with a male:female ratio of 54:44. The average time from transplantation to urolithiasis onset was 47.54 ± 23.9 months. Predominant symptoms upon presentation were AKI (32.3%), followed by urinary tract infection and fever (24.2%), and oliguria (12.9%). The mean stone size was 20.1 ± 7.3 mm, with stones located in the calices or pelvis (41%), ureteropelvic junction (23.1%), or proximal ureter (28.2%). PCNL (22F-30F) was more frequently performed than mini-PCNLs (16F-20F) (52.4% vs 47.6%). Puncture was guided by ultrasound (42.9%), fluoroscopy (14.3%), or both (42.9%). The stone-free rate (SFR) and complication rates were 92.95% (range: 77%-100%) and 5.5%, respectively, with only one major complication reported. Postoperatively, a ureteral stent and nephrostomy were commonly placed in 47%, with four patients needing a second look PCNL. During an average follow-up of 32.5 months, the recurrence rate was 3.7% (4/108), and the mean creatinine level was 1.37 ± 0.28 mg/dL. Conclusions: PCNL remains a safe and effective option in de novo allograft urolithiasis, allowing to treat large stones in one-step surgery. A good SFR is achieved with a low risk of minor complications. These patients should be treated in an endourology center in conjunction with the renal or transplant team.

Thulium Fiber Laser Versus Holmium:Yttrium Aluminum Garnet for Lithotripsy: A Systematic Review and Meta-analysis.

CONTEXT: Thulium fiber laser (TFL) emerged as a competitor of holmium:yttrium aluminum garnet (Ho:YAG) laser for the treatment of urinary stones. OBJECTIVE: To compare the efficacy between Ho:YAG and TFL for laser lithotripsy of renal and ureteral stones. EVIDENCE ACQUISITION: A literature search was conducted using PubMed/Medline, Embase, and Web of Science databases to identify reports published until May 2023. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed to identify eligible studies. The primary outcome was to compare the stone-free rate (SFR) between Ho:YAG and TFL for laser lithotripsy. EVIDENCE SYNTHESIS: Eleven studies met our inclusion criteria, and data from 1286 and 880 patients who underwent, respectively, Ho:YAG and TFL laser lithotripsy were reviewed. Most studies included ureteroscopy (URS) and retrograde intrarenal surgeries as procedures, two included percutaneous nephrolithotomy, and one included URS exclusively. Only two studies reported results in pediatric patients. TFL was associated with a higher SFR (odds ratio [OR] 1.84, 95% confidence interval [CI]: 1.06-3.20; p = 0.031) when no residual fragment is considered, but not when SFR refers to the presence of fragments <3 mm (OR 2.48, 95% CI: 0.98-6.29; p = 0.055) or when only Ho:YAG with MOSES is considered (p = 0.068). According to the stones' location, TFL was associated with higher SFRs than Ho:YAG for renal (OR 3.14, 95% CI: 1.69-5.86; p < 0.001) but not for ureteral (p = 0.8) stones. TFL was associated with a lower intraoperative complication rate (OR 0.34, 95% CI: 0.19-0.63; p < 0.001). No difference was found in major (p = 0.4) or overall (p = 0.4) complication rate, operative time (p = 0.051), and laser time (p = 0.9). CONCLUSIONS: TFL is a promising laser for the treatment of urinary stones with some advantages over Ho:YAG. Further high-quality studies are needed to confirm these findings and optimize the surgical settings. PATIENT SUMMARY: The use of thulium fiber laser rather than holmium:yttrium aluminum garnet permits to reach a higher stone-free rate in stones located in the kidney rather than in the ureter.

Suction in Percutaneous Nephrolithotripsy: Evolution, Development, and Outcomes from Experimental and Clinical studies. Results from a Systematic Review.

CONTEXT: Controversy exists regarding the therapeutic benefit of suction use during percutaneous nephrolithotripsy (PCNL). OBJECTIVE: To review and highlight the options available in the use of suction for PCNL, and to discuss their strengths and limitations. EVIDENCE ACQUISITION: A systematic literature search was performed using Scopus, EMBASE, and PubMed. Thirty four studies were included. There was one ex vivo study. Among clinical studies, 24 used a vacuum/suctioning sheath and nine a handpiece suction device/direct-in-scope suction. The suction technique was employed in standard, mini-PCNL, supermini-PCNL, and enhanced supermini­PCNL techniques. EVIDENCE SYNTHESIS: Handpiece suction devices demonstrated better safety and efficiency in treating large stones than nonsuction PCNL and in a much shorter time. Trilogy and ShockPulse-SE were equally effective, safe, and versatile for standard PCNL and mini-PCNL. The heavier handpiece makes Trilogy less ergonomically friendly. Laser suction handpiece devices can potentiate laser lithotripsy by allowing for better laser control with simultaneous suction of small fragments and dust. Integrated suction-based sheaths are available in reusable and disposable forms for mini-PCNL only. Mini-PCNL with suction reported superior outcomes for operative time and stone-free rate to mini-PCNL. This also helped minimize infectious complications by a combination of intrarenal pressure reduction and faster aspiration of irrigation fluid reducing the risk of sepsis, enhance intraoperative vision, and improve lithotripsy efficiency, which makes it a very attractive evolution for PCNL. CONCLUSIONS: Suction devices in PCNL are reforming the way PCNL is being done. Adding suction to mini-PCNL reduces infectious complications and improves the stone-free rate. Our review shows that despite the limited evidence, suction techniques appear to improve PCNL outcomes. PATIENT SUMMARY: In this review, we looked at the intra- and perioperative outcomes of percutaneous nephrolithotripsy (PCNL) with the addition of suction. With better stone fragmentation and fewer postoperative infections, this technology is very useful particularly for mini-PCNL.

Can Perioperative Antibiotic Choice Impact Rates of Infectious Complications After Percutaneous Nephrolithotomy? A Single-Blind, Prospective Randomized Trial.

Objective: National guidelines recommend periprocedural antibiotics before percutaneous nephrolithotomy (PCNL), yet it is not clear which is superior. We conducted a randomized trial to compare two guideline-recommended antibiotics: ciprofloxacin (cipro) vs cefazolin, on PCNL outcomes, focusing on the development of systemic inflammatory response syndrome (SIRS) criteria. Methods: Adult patients who were not considered high risk for surgical or infectious complications and undergoing PCNL were randomized to receive either cipro or cefazolin perioperatively. All had negative preoperative urine cultures. Demographic and perioperative data were collected, including SIRS criteria, intraoperative urine culture, duration of hospitalization, and need for intensive care. SIRS is defined by ≥2 of the following: body temperature <96.8°F or >100.4°F, heart rate >90 bpm, respiratory rate >20 per minute, and white blood cell count <4000 or >12,000 cells/mm3. Results: One hundred forty-seven patients were enrolled and randomized (79 cefazolin and 68 cipro). All preoperative characteristics were similar (p > 0.05), except for mean age, which was higher in the cipro group (64 vs 57 years, p = 0.03). Intra- and postoperative findings were similar, with no difference between groups (p > 0.05), except a longer mean hospital stay in the cefazolin group (2 hours longer, p = 0.02). There was no difference between SIRS episodes in both univariate and multivariate analyses. Conclusions: Despite the relatively broader coverage for urinary tract pathogens with ciprofloxacin, this prospective randomized trial did not show superiority over cefazolin. Our findings therefore support two appropriate options for perioperative antibiotic prophylaxis in patients undergoing PCNL who are nonhigh risk for infectious complications.

Endoscopic Stone Composition Identification: Is Accuracy Improved by Stone Appearance During Laser Lithotripsy?

OBJECTIVE: To evaluate if videos during laser lithotripsy increase accuracy and confidence of stone identification by urologists compared to still pictures. METHODS: We obtained representative pictures and videos of 4 major stone types from 8 different patients during ureteroscopy with holmium laser lithotripsy. A REDCap survey was created and emailed to members of the Endourological Society. The survey included a picture followed by the corresponding video of each stone undergoing laser lithotripsy and additional clinical information. Each picture and video included multiple-choice questions about stone composition and response confidence level. Accuracy, confidence levels, and rates of rectification (change from incorrect to correct answer) or confounding (correct to incorrect) after watching videos were analyzed. RESULTS: One hundred eighty-seven urologists responded to the survey. The accuracy rate of stone identification with pictures was 43.8% vs 46.1% with videos (P = .27). Accuracy for individual stones was low and highly variable. Video only improved accuracy for 1 cystine stone. After viewing videos, participants were more likely to rectify vs confound their answers. Urologists were more likely to be confident with videos than pictures alone (65.4% vs 53.7%, respectively; P <.001); however, confident answers were not more likely to yield accurate predictions with videos vs still pictures. CONCLUSION: Stone identification by urologists is marginally improved with videos vs pictures alone. Overall, accuracy in stone identification is low irrespective of confidence level, picture, and lithotripsy video visualization. Urologists should be cautious in using endoscopic stone appearance to direct metabolic management.

Sustainability in Urology: Ideas for a Greener Future.

Sustainability in urology can be achieved via conscientious practices that minimize the negative impact of our services while achieving ethical and responsible patient care. We highlight novel and actionable ideas that could pave the path towards healthier, greener urological practice.

Shockwave Lithotripsy for De-Novo Urolithiasis after Kidney Transplantation: A Systematic Review of the Literature.

BACKGROUND: Allograft urolithiasis is an uncommon, challenging, and potentially dangerous clinical problem. Treatment of allograft stones includes external shockwave lithotripsy (SWL), flexible ureteroscopy and lasertripsy (fURSL), or percutaneous nephrolithotomy (PCNL). A gap in the literature and guidelines exists regarding the treatment of patients in this setting. The aim of this systematic review was to collect preoperative and treatment characteristics and evaluate the outcomes of post-transplant SWL for stone disease. METHODS: A systematic search in the literature was performed, including articles up to March 2023. Only original English articles were selected. RESULTS: Eight articles (81 patients) were included in the review. Patients were mainly male, with a mean age of 41.9 years (±7.07). The mean stone size was 13.18 mm (±2.28 mm). Stones were predominantly located in the kidney (n = 18, 62%). The overall stone-free rate and complication rates were 81% (range: 50-100%) and 17.2% (14/81), respectively, with only one major complication reported. A pre-operative drainage was placed in eleven (13.5%) patients. Five patients (6.71%) required a second treatment for residual fragments. CONCLUSIONS: SWL is a safe and effective option to treat de novo stones after transplantation. Larger studies are needed to better address allograft urolithiasis management.

Erector spinae plane blocks for analgesia after percutaneous nephrolithotomy A pathway to reduce opioids.

INTRODUCTION: Despite its minimally invasive nature, percutaneous nephrolithotomy (PCNL ) may be associated with significant pain. Challenges in pain control may prevent timely discharge (and expose patients to adverse effects of opioid use). We sought to evaluate whether our patients who underwent erector spinae plane (ESP) regional blocks experienced improved postoperative pain control and decreased opioid use after PCNL (compared with those who did not receive blocks). METHODS: We retrospectively reviewed consecutive PCNL cases on patients admitted for greater than 24 hours without pre-existing opioid regimens for chronic pain. Cases were completed by a single high-volume surgeon. Patients who accepted an ESP block were compared to those who did not receive a block. Patients received either a single injection or a disposable pump delivering intermittent boluses of ropivacaine 0.2%. Demographic and perioperative data were analyzed. The primary outcomes were opioid use measured in morphine milligram equivalent (MME ) and patient-reported pain scores during the first 24 hours of hospitalization. RESULTS: From March 2019 to August 2021, 44 patients were identified who met criteria - 28 of whom received an ESP block (including 14 continuous blocks). The patients who received blocks had significantly decreased opioid use (18.3 vs. 81.3 MME, p=0.004) and a longer mean time to first non-zero pain score (p=0.004). Continuous blocks had similar opioid use to single shot blocks (21.0 vs. 15.6 MME, p=0.952). CONCLUSIONS: ESP regional blocks appear to offer an effective adjunct method for pain control after PCNL and may reduce post-PCNL opioid use while maintaining adequate patient analgesia.

Quick Sequential Organ Failure Assessment Score Is a Better Predictor of Septic Shock After Percutaneous Nephrolithotomy: A Secondary Analysis of Two Multicenter Prospective Trials.

Introduction: Recent retrospective literature suggests that the quick sequential organ failure assessment (qSOFA) scoring tool is a potentially superior tool over use of the systemic inflammatory response syndrome (SIRS) criteria to predict septic shock after percutaneous nephrolithotomy (PCNL) surgery. Here we examine use of qSOFA and SIRS to predict septic shock within data series collected prospectively on PCNL patients as part of a greater study of infectious complications. Materials and Methods: We performed a secondary analysis of two prospective multicenter studies including PCNL patients across nine institutions. Clinical signs informing SIRS and qSOFA scores were collected no later than postoperative day 1. The primary outcome was sensitivity and specificity of SIRS and qSOFA (high-risk score of greater-or-equal to two points) in predicting admission to the intensive care unit (ICU) for vasopressor support. Results: A total of 218 cases at 9 institutions were analyzed. One patient required vasopressor support in the ICU. The sensitivity/specificity was 100%/72.4% (McNemar's test p < 0.001) for SIRS and was 100%/90.8% (McNemar's test p < 0.001) for qSOFA. Conclusion: Although positive predictive value for both qSOFA and SIRS in prediction of post-PCNL septic shock is low, prospectively collected data demonstrate use of qSOFA may offer greater specificity than SIRS criteria when predicting post-PCNL septic shock.

Long-term follow-up on dusting versus basketing during ureteroscopy: a prospective multicenter trial from the EDGE Research Consortium.

In 2018, the Endourology Disease Group for Excellence (EDGE) published a prospective trial comparing dusting versus basketing during ureteroscopy. One hundred fifty-nine patients were included in the original analysis, which found no difference in stone-free rate at 3 months. We report the intermediate and long-term outcomes of patients included in the original trial. Two analyses were performed. At 1-year, a retrospective chart review was performed, and data collected on stone episodes, Emergency Department (ED) visits, hospital admissions and surgical interventions. To obtain long-term outcomes, the four sites with the largest initial accrual were included in a second phase of data collection with updated analyses. The patients from those sites were contacted, re-consented, and data were collected on stone surgical interventions, stone episodes, stone recurrences on imaging, emergency department (ED) visits, and hospital admissions for stone-related care since their original procedure. One-year follow-up data were collected in 111 of the original 159 (69.8%) patients from the nine sites. There were no statistically significant differences in the number of painful episodes, ED visits, hospital admissions, or surgical interventions. 94 patients from four sites were included in the long-term analysis. There were no statistically significant differences in surgical interventions, painful stone episodes, stone recurrence on imaging, ED visits or hospitalizations for stone-related events between the two groups. Long-term outcomes of dusting versus basketing during ureteroscopy indicate that there are no significant differences in clinical outcomes between the two surgical modalities.

Prevalence of Stone Disease and Procedure Trends in the United States.

OBJECTIVE: To evaluate the prevalence of stone disease and procedure trends among US commercial and Medicare populations. METHODS: Retrospective analyses for a US commercial population and Medicare population were conducted using the Merative MarketScan Commercial Database and Medicare Standard Analytic File (5% sample), respectively. Patients aged 18+ were included if they had an encounter in any setting with a primary stone diagnosis or stone procedure (ureteroscopy [URS], percutaneous nephrolithotomy (PCNL), or shockwave lithotripsy [SWL]) between 2011 and 2019. Analyses were conducted at the patient level. RESULTS: Over the study time horizon, the prevalence of stone disease showed a small yet statistically significant decrease in the commercial population (1.04%-1.01%; P.ß<.ß0.0001) and a statistically significant increase in the Medicare population (1.84%-2.34%; P.ß<.ß0.0001). URS.ßprocedure volumes increased by 22.6% (P.ß<.ß0.0001) in the commercial population and by 56.6% (P.ß<.ß0.0001) in the Medicare population over the study period. Similarly, PCNL.ßprocedure volumes increased by 17.4% (P.ß<.ß0.0001) in the commercial population and 27.5% (P.ß<.ß0.0001) in the Medicare population. Procedure volumes for SWL decreased by 26.9% in the commercial population (P.ß<.ß0.0001) and by 3.8% in the Medicare population although the results were not statistically significant. CONCLUSION: The prevalence of stone disease showed a small decrease in the US commercial population and an increase in the Medicare population over the study time horizon. In both populations, increasing procedure volumes were observed for URS and PCNL while decreasing volumes were observed for SWL.

Sepsis prevalence and associated hospital admission and mortality after ureteroscopy in employed adults.

OBJECTIVE: To determine 30-day inpatient mortality, intensive care unit (ICU) admissions, inpatient admissions/readmissions, and yearly trends in sepsis prevalence and inpatient mortality after ureteroscopy (URS) in employed adults. MATERIALS AND METHODS: We performed a retrospective analysis of the IBM MarketScan Commercial Database to identify employed adults aged 18-64 years who underwent URS between 2015 and 2019. Patients were categorized as having no sepsis (controls), non-severe sepsis, or severe sepsis within 30 days of URS. The main outcomes included inpatient mortality, ICU admissions, inpatient admissions, readmissions, and annual rates of sepsis and associated inpatient mortality. RESULTS: Among 109 496 patients undergoing URS, 5.6% developed sepsis (4.1% non-severe, 1.5% severe). The 30-day inpatient mortality rates were 0.03%, 0.3% and 2.5% for controls, non-severe sepsis and severe sepsis, respectively (P < 0.001). In a multivariable analysis, diagnosis of sepsis regardless of severity (hazard ratio [HR] 17.2, 95% confidence interval [CI] 10.5-28.1; P < 0.001) or severe sepsis (HR 49.5, 95% CI 28.9-84.7; P < 0.001) increased the risk of 30-day inpatient mortality compared to no sepsis (controls). ICU admissions on the day of procedure (1.5%, 19.8% and 52.4%), inpatient admission rates (18.3%, 74.9% and 76.9%) and readmission rates (7.1%, 12.0% and 15.9%) were higher with severe sepsis and non-severe sepsis vs controls (all P < 0.001). During the study period, the prevalence of sepsis after URS increased from 4.7% to 6.6% (P < 0.001), while the associated mortality rate decreased from 0.7% to 0.2% (P < 0.001). CONCLUSION: Among working adults aged 18-64 years, sepsis after URS increases the risk of 30-day inpatient mortality, ICU and hospital admission, and hospital readmission. Although the prevalence of sepsis after URS is increasing over time, associated mortality rates are declining. Urologists should be aware of the potentially deadly consequences of sepsis after URS in younger patients.

Clinical Evaluation of Miniature Flexible Scope for Diagnosis of Ureteroscope Working Channel Defects.

Introduction: To evaluate flexible ureteroscope working channels with a 1.06 mm digital borescope (Clarus Medical, Minneapolis, MN) and identify factors contributing to ureteroscope damage over time. Materials and Methods: We performed a single institutional prospective study of patients undergoing stone surgery using a nondisposable flexible ureteroscope. A 1.06 mm borescope was used to evaluate ureteroscopes before and after surgery. Borescope videos were reviewed by two independent researchers to quantify average pre- and postprocedural damage. Results: Twenty-five procedures were performed with pre- and postprocedural borescope assessment between August 2021 and February 2022. All patients received preoperative CT imaging depicting a mean axial stone size of 14.1 ± 8.4 mm and density of 923.4 ± 458.1 HU. Mean operative time was 63.8 ± 34.0 minutes. The average number an instrument passes through the working channel was 2.1 ± 1.6. Laser was used in 11 cases with mean laser time of 18.8 ± 19.7 minutes and mean total energy of 5.8 ± 4.2 KJ. On preoperative assessment, all ureteroscopes had some form of defect (24% shave, 32% pinhole, 96% dents and scratches, and 28% discolorations). During postoperative assessment, 23/25 (92%) ureteroscopes showed additional damage with an average of 3.7 ± 2.8 imperfections acquired after one use. Significant differences were seen in acquired shavings (p = 0.028) and scratches or dents (p = 0.018). Of the 355 imperfections seen on postoperative evaluation, 0.4% were shave, 3% were pinhole, 85.8% were dents and scratches, and 10.8% were discolorations. Conclusion: The Clarus borescope observed defects after the majority of flexible ureteroscopy procedures for nephrolithiasis. Although such disruptions may not immediately render ureteroscopes nonfunctional, they are more common than previously described and could increase maintenance costs. Further studies are needed to investigate the burden of unit damage per procedure to raise operator awareness and reduce preventable ureteroscope imperfections.

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.

Understanding Causes for Admission in Planned Ambulatory Percutaneous Nephrolithotomy.

Introduction: For treatment of nephrolithiasis, ambulatory percutaneous nephrolithotomy (aPCNL) is growing in popularity for select patients. The aim of this study was to investigate the safety and efficacy of a set of aPCNL selection criteria as well as search for predictors of failed aPCNL resulting in inpatient admission. Materials and Methods: We reviewed all percutaneous nephrolithotomy (PCNL) patients from 2016 to 2020. A total of 175 met selection criteria for aPCNL and were included. Primary outcome was safety and efficacy, and secondary outcome was to identify predictors of inpatient stay. Demographic and perioperative data were analyzed with both descriptive and inferential statistics. Results: In total, between 2016 and 2020, 552 patients underwent PCNL, with 175 of them meeting criteria for aPCNL. One hundred thirty-four of the 175 (76.6%) of these patients were discharged the same day as the surgery and 41 patients were admitted. On univariate analysis, patients who required upper pole access or multiple accesses (p = 0.038) American Society of Anesthesiologists >2 (p = 0.005), or postoperative nephrostomy (PCN) tube (p < 0.001) were more likely to be admitted after surgery. On multivariate analysis, only postoperative PCN was significantly associated with admission (p = 0.015). Regarding reasons for unsuccessful aPCNL, 19.5% of admissions were attributed to intraoperative complications, 7% to social causes, 12.2% to postoperative complications, 14.6% to uncontrolled pain, and 34.1% to unexpected intraoperative procedures. Conclusions: aPCNL using selection criteria is safe and effective, with postoperative PCN predicting the possible necessity for conversion to inpatient admission. Furthermore, our study provides a practical algorithm for those opting to provide aPCNL to patients.

Delineating the Role of the Urinary Metabolome in the Lithogenesis of Calcium-Based Kidney Stones.

OBJECTIVE: To delineate the role of the urinary metabolome in the genesis of urinary stone disease (USD). METHODS: Untargeted metabolomics was utilized in comparative analyses of calcium-based stones (CBS) and spot urine samples from patients with a history of USD with or without urinary stone activity based on radiologic imaging. Stone and urine metabolomes were stratified by composition and radiographic stone-activity, respectively. Additionally, we quantified highly abundant metabolites that were present in either calcium oxalate (CaOx) or calcium phosphate (CaPhos) stones and also significantly enriched in the urine of active stone formers (SF) compared to non-active SF. These data were used to delineate either a direct involvement of urinary metabolites in lithogenesis or the passive uptake of biomolecules within the stone matrix. RESULTS: Urinary metabolomes were distinct based on radiographic stone-activity and the 2 types of CBS. Stratification by radiologic stone activity was driven by the enrichment of 14 metabolites in the urine of active SF that were also highly abundant in both CaOx and CaPhos stones, indicative of a potential involvement of these metabolites in lithogenesis. Using the combination of these 14 metabolites in total, we generated a model that correctly classified patients as either active vs non-active SF in a prospectively recruited cohort with 73% success. CONCLUSION: Collectively, our data suggest specific urinary metabolites directly contribute to the formation of urinary stones and that active SF may excrete higher levels of lithogenic metabolites than non-active patients. Future studies are needed to confirm these findings and establish the causative mechanisms associated with these metabolites.

Micro-elemental analysis and characterization of major heavy metals and trace elements in the urinary stones collected from patients living in diverse geographical regions.

In the process of urinary stone formation, several heavy metals and trace elements (HMTE) have been identified among the major constituents of the calculi. The micro-elements within the stones cannot be identified by ordinary laboratory analytical techniques, the latter can only detect the major crystalline component. The objective of the present study was to evaluate the different types of HMTE (no. 22) and their concentrations within the urinary stones. The stone samples were obtained from patients living in different geographical locations (10 countries: 5 Western and 5 non-Western). The number of retrieved stones after open or endoscopic procedures was 1177. The concentrations of the 22 HMTE in the stones were assessed by inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical data were analyzed using Kruskal-Wallis, one-way ANOVA, and SPSS software (version 20). The biochemical stone analysis showed that calcium oxalate was present as a major component in 650 patients (55.2%), calcium phosphate in 317 (26.9%), and uric acid and cystine stones in 210 (17.8%). The analyzed stones showed the presence of HMTE in different concentrations. Significantly higher concentrations of 17 elements (Al, As, Ba, B, Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, S, Se, Sr, and Zn) were noted in all stones. Seven elements (Al, As, Se, Sr, Fe, Zn, and Ni) were present in higher concentrations in calcium-based stones. In comparison, eight elements (Mg, B, Ba, Cd, Se, Pb, Sr, and Zn) in higher concentrations were associated with phosphate-based stones. Both uric acid and cystine stones had a higher concentration of sulfur. The concentrations of HMTE in calcium phosphate stones were higher than in calcium oxalate and uric acid stones. Calculi obtained from patients living in western countries contained higher levels of 13 HMTE (B, Ba, Ca, Cd, Co, Cu, Fe, K, Mg, Mo, P, Pb, and Se) than those in non-western countries. The age of calculi-forming patients from non-western countries was younger than those living in western countries. These results may indicate the role of many significant heavy metals and trace elements in the pathogenesis of urinary stone formation. The types and contents of HMTE within urinary stones differ from one country to another. The conventional stone analysis techniques cannot either identify the stone micro-elements or the concentrations of HMTE, so a specific and additional instrument such as the ICP-OES is necessary. Further research work on the urinary stone micro-elemental structure could lead to a new strategy for the prevention of stone formation and recurrence.

Standardizing Perioperative Medications to Be Used in an Enhanced Recovery After Surgery Program Is Feasible in Percutaneous Nephrolithotomy Patients.

Introduction: The objective of this process improvement project was to determine the effect of enhanced recovery after surgery (ERAS) protocol for percutaneous nephrolithotomy (PCNL) patients with respect to quality of life (QOL) and pain management in the postoperative recovery period. Methods: An electronic-based medical record ERAS orders protocol for PCNL was instituted at an academic medical center in July 2020. The protocol utilized a pain control regimen designed to minimize opioid medication use postoperatively. We prospectively evaluated PCNL patients' QOL through the Wisconsin Stone Quality of Life (WISQOL) survey and Patient-Reported Outcomes Measurement System (PROMIS) at routine perioperative visits. To assess any opioid reduction benefit of the ERAS protocol, we reviewed an age-matched historical cohort n = 66 (before ERAS implementation) to serve as a comparison cohort with respect to opioid usage. Results: After an inception cohort of 95 patients, 55 ERAS patients remained available for assessment with the WISQOL and PROMIS surveys. In comparison with the non-ERAS cohort, the ERAS cohort represented larger stones, more supine positioning, higher blood loss, shorter hospital stay, and more use of access sheath. ERAS patients received a significantly lower amount of opioids compared with non-ERAS patients upon discharge narcotic usage (116.13 morphine milliequivalent [MME] vs 39.57 MME, p = 0.0001). Compared with their preoperative evaluation, the ERAS cohort had significantly improved QOL scores at 1 week, which sustained through 8 weeks postoperatively. Moreover, pain intensity and pain interference scores were improved at 8 weeks postoperatively for ERAS patients compared with their preoperative time point. Conclusions: We demonstrate that standardizing medications in early efforts toward a PCNL ERAS protocol is feasible and allows for reduced opioid use by patients while achieving early and sustained postprocedure QOL.