Postoperative events and complications of next-day stent removal following uncomplicated percutaneous nephrolithotomy compared to longer stenting.

INTRODUCTION: Options for renal drainage after percutaneous nephrolithotomy (PCNL) vary and depend primarily on surgeon preference and case considerations. In our practice, patients traditionally returned one week postoperatively to remove the stents in the office via cystoscopy; however, following uncomplicated PCNL with no plans for second-look procedure, a ureteral stent on a tether is currently removed in tandem with the Foley catheter on postoperative day 1 (POD1) prior to patient discharge. This study compared the number of postoperative events between POD1 stent removal and their longer stented counterparts. METHODS: We conducted a retrospective chart review on all patients who had undergone PCNL at our institution from January 1, 2020, to June 31, 2021. Patient demographics, operative metrics, and postoperative events (telephone calls, emergency department [ED ]/clinic visits, and complications) were recorded and compared between the two groups. RESULTS: A total of 243 patients were included in final analysis: 46% (n=111) had their stent removed on POD1 and 54% (n=132) had longer indwelling stent times. Baseline demographics were similar between the two groups. Number of telephone calls (p=0.081), ED /clinic visits (p=0.093), and complications (p=0.647) were similar between groups. There were three (1.3%) unplanned second-look procedures: two (1.8%) in the POD1 stent removal group and one (0.8%, p=0.475) in the later stent removal group. CONCLUSIONS: In this limited, retrospective study, we did not detect a difference in postoperative events or short-term complications for POD1 vs. later stent removal after uncomplicated PCNL.

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.

Comparing dusting and fragmenting efficiency using the new SuperPulsed thulium fiber laser versus a 120 W Holmium:YAG laser.

PURPOSE: Holmium:YAG laser lithotripsy requires high amperage power and has an upper limit of frequency and a minimal fiber size. The technology utilizing thulium-doped fiber offers low pulse energy settings and high pulse frequencies up to 2,400 Hz. We compared the novel SuperPulsed thulium fiber laser (SOLTIVE™; Olympus) to a commercially available 120 W Ho:YAG laser. MATERIALS AND METHODS: Bench-top testing was conducted with 125 mm3 standardized BegoStones (Bego USA). Time to ablate the stone into particles <1 mm was recorded for efficiency calculations. Finite energy was delivered, and resulting particle sizes were measured to determine fragmentation (0.5 kJ) and dusting (2 kJ) efficiencies. Remaining mass or number of fragments were measured to compare efficacy. RESULTS: SOLTIVE™ was faster at ablating stones to particles <1 mm (2.23±0.22 mg/s, 0.6 J 30 Hz short pulse) compared to Ho:YAG laser (1.78±0.44 mg/s, 0.8 J 10 Hz short pulse) (p<0.001). Following 0.5 kJ of energy in fragmentation testing, fewer particles >2 mm remained using SOLTIVE™ than Ho:YAG laser (2.10 vs. 7.20 fragments). After delivering 2 kJ, dusting (1.05±0.08 mg/s) was faster using SOLTIVE™ (0.1 J 200 Hz short pulse) than 120 W 0.46±0.09 mg/s (0.3 J 70 Hz Moses) (p=0.005). SOLTIVE™ (0.1 J 200 Hz) produced more dust particles <0.5 mm (40%) compared to 24% produced by the P120 W laser at 0.3 J 70 Hz Moses and 14% at 0.3 J 70 Hz long pulse (p=0.015). CONCLUSIONS: The efficacy of SOLTIVE™ is superior to the 120 W Ho:YAG laser by producing smaller dust particles and fewer fragments. Further studies are warranted.

The impact of single-use digital flexible cystoscope for double J removal on hospital costs and work organization: A multicentric evaluation.

BACKGROUND: Isiris-α® is a single-use digital flexible cystoscope with an integrated grasper designed for double J (DJ) stent removal. Aim of this study was to conduct a multicentric evaluation of the costs and criticalities of stent removals performed with Isiris®-α in different hospitals and health systems, as compared to other DJ removal procedures. METHODS: After gathering 10 institutions worldwide with experience on Isiris-α®, we performed an analysis of the reported costs of DJ removal with Isiris-α®, as compared to the traditional reusable equipment used in each institution. The cost evaluation included instrument purchase, Endoscopic Room (EnR)/ Operatory Room (OR) occupancy, medical staff, instrument disposal, maintenance, repairs, decontamination or sterilization of reusable devices. RESULTS: The main factor affecting the costs of the procedure was OR/EnR occupancy. Decontamination and sterilization accounted for a less important part of total costs. Isiris-α® was more profitable in institutions where DJ removal is usually performed in the EnR/OR, allowing to transfer the procedure to outpatient clinic, with a significant cost saving and EnR/OR time saving to be allocated to other activities. In the only institution where DJ removal was already performed in outpatient clinics, there is a slight cost difference in favor of reusable instruments in high-volume institutions, given a sufficient number to guarantee the turnover. CONCLUSION: Isiris-α® leads to significant cost benefit in the institutions where DJ removal is routinely performed in EnR/OR, and brings significant improvement in organization, cost impact and turnover.

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).

Improving Access and Quality of Care for Kidney Stone Patients in an Underserved Community.

There is a call to improve Medicaid patient access to health care, enhance quality and outcomes of care, and reduce overall financial burden. We sought to build a comprehensive kidney stone program to help patients navigate through the acute and preventive aspects of stone disease by increasing multidisciplinary referrals and compliance with recommendations and decreasing no-show rates at first follow-up and repeat stone encounters after initial evaluation. A collaborative multidisciplinary program was established at our single institution consisting of urology, nephrology, and dietary specialists to be piloted over a 3-year period. Medicaid-designated patients were evaluated during new patient encounters by urology specialists and then followed for outpatient follow-up, including specialty referrals to nephrology specialists and dietitians, for targeted preventive measures. Subjective compliance reports by patients following interventions and no-show rates at subsequent follow-ups were documented. We also followed patients 6 months beyond the initial encounter to assess repeat Emergency Department (ED) visits for acute stone episodes. One hundred eighty-three Medicaid-designated stone patients were evaluated from 2018 to 2021. Sixty-eight percent of patients identified as White, 18% identified as Black/African American, and 14% identified as "Other." Patients underwent specialty referrals to nephrology or a dietician in 47% and 42% of cases, respectively. Since the program's implementation, reported patient compliance and referrals to multidisciplinary specialists increased from 72.9% to 81.30% and 21.2% to 56.20%, respectively. Repeat ED visits for stone-related encounters within 6 months of initial presentation remained relatively stable (from 17.60% to 18.9%), while no-show rates at first follow-up decreased from 20.0% to 6.30% by study conclusion. There is continued supporting evidence for the importance of a comprehensive kidney stone program specifically for patients of lower socioeconomic status following a 3-year implementation at our institution. Encouraging results indicate increased access to multidisciplinary specialty referrals, with improvement in follow-up and reported compliance related to stone prevention strategies.

Fellowship training in endourology: Impact on percutaneous nephrolithotomy access patterns.

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) remains the treatment of choice for kidney stones larger than 2 cm. Few studies have examined the reasons why some urologists obtain their own PCNL access while others prefer to have interventional radiology (IR) obtain access. The objective of this study was to investigate what factors influence this decision. METHODS: A survey was posted to the American Urological Association's (AUA) Young Urologist Community. Descriptive statistics and exploratory analyses were used to summarize practice trends and motivating factors. RESULTS: All 99 respondents began practicing within the past 11 years. Ninety-two currently perform PCNLs and 47% of them obtain their own access. Endourology fellowship-trained physicians were more likely to currently obtain their own access (75%) compared to urologists who completed non-endourology fellowships (75% vs. 23%, p=0.58) and non-fellowship-trained urologists (75% vs. 45%, p=0.01). Logging >50 cases during training also predicted physicians obtaining their own access and having a larger annual number of PCNL cases. The most common motivator for obtaining one's own access was preference to control their own access point (95%). CONCLUSIONS: Urologist-obtained PCNL access was associated with greater training experience (endourology fellowship) and current annual PCNL case volume. Urologist-reported factors that influenced the decision to obtain one's own access include control of access, comfort level, and both physician and patient convenience. By identifying the factors that influence practice patterns, we may better address barriers, improve education to make urologistobtained PCNL access feasible even without fellowship training, and ultimately improve outcomes and quality of care.

Multi-Institutional Prospective Randomized Control Trial of Novel Intracorporeal Lithotripters: ShockPulse-SE vs Trilogy Trial.

Introduction: Currently, there are multiple intracorporeal lithotripters available for use in percutaneous nephrolithotomy (PCNL). This study aimed to evaluate the efficiency of two novel lithotripters: Trilogy and ShockPulse-SE. Materials and Methods: This is a prospective multi-institutional randomized trial comparing outcomes of PCNL using two novel lithotripters between February 2019 and June 2020. The study assessed objective measures of stone clearance time, stone clearance rate, device malfunction, stone-free rates, and complications. Device assessment was provided through immediate postoperative survey by primary surgeons. Results: There were 100 standard PCNLs completed using either a Trilogy or ShockPulse-SE lithotrite. Using quantitative Stone Analysis Software to estimate stone volume, the mean stone volume was calculated at 4.18 ± 4.79 and 3.86 ± 3.43 cm3 for the Trilogy and ShockPulse-SE groups, respectively. Stone clearance rates were found to be 1.22 ± 1.67 and 0.77 ± 0.68 cm3/min for Trilogy vs ShockPulse-SE (p = 0.0542). When comparing Trilogy to ShockPulse-SE in a multivariate analysis, total operative room time (104.4 ± 48.2 minutes vs 121.1 ± 59.2 minutes p = 0.126), rates of secondary procedures (17.65% vs 40.81%, p = 0.005), and device malfunctions (1.96% vs 34.69%, p < 0.001) were less, respectively. There was no difference in final stone-free rates between devices. Conclusion: Both the Trilogy and ShockPulse-SE lithotripters are highly efficient at removing large renal stones. In this study, we noted differences between the two devices including fewer device malfunctions when Trilogy device was utilized. Clinical Trial ID number: NCT03959683.

Ureteroscopic Performance of High Power Super Pulse Thulium Fiber Laser for the Treatment of Urolithiasis: Results of the First Case Series in North America.

OBJECTIVE: To report the first case series of ureterorenoscopy in North America using the High Power Super Pulse Thulium Fiber Laser for the treatment of upper urinary tract stones. METHODS: After Institutional Review Board approval, a multicentric retrospective chart review of patients treated with the High Power Super Pulse Thulium Fiber Laser from October 2019 to March 2020 was conducted. Basic demographic information, pre-operative, and peri-operative data were recorded. RESULTS: Seventy-six patients were included with a mean age of 60.9 ± 13.3 years. 118 stones were treated including 32 within the ureter, 49 in the lower pole, 37 in mid or upper poles. Dusting technique was commonly used (67.1%) with pulse frequencies up to 2400 Hz. Mean operative time was 59.4 ± 31.5 minutes. Mean laser time and total laser energy were 10.8 ± 14.1 minutes and 12.5 ± 19.1 KJ, respectively. Intraoperative complications were limited to 7 grade 1, 3 grade 2, and 1 grade 3 ureteral injuries and one case of renal collecting system bleeding that was adequately managed with laser coagulation settings (1J-20Hz). CONCLUSION: This initial case series in North America of the High Power Super Pulse Thulium Fiber Laser is promising for the treatment of urolithiasis. Sub-200 µm fibers and dusting settings up to 2400 Hz were utilized successfully. No specific complications related to use of the laser were seen.

Temperature rise during ureteral laser lithotripsy: comparison of super pulse thulium fiber laser (SPTF) vs high power 120 W holmium-YAG laser (Ho:YAG).

PURPOSE: The holmium-YAG (Ho:YAG) Laser system is the current gold standard for laser lithotripsy (LL). Super Pulse Thulium Fiber Laser (SPTF) has emerged as an effective alternative. We compared the temperature profile of both the 120 W Ho:YAG and the 60 W SPTF systems during ureteral lithotripsy. METHODS: Antegrade ureteroscopy with LL was performed in ex-vivo porcine kidneys with 3 mm Begostones. Intra-ureteral temperature was measured using one probe proximal and one distal to the site of lithotripsy. LL was performed using a 200 µm core fiber at dusting (SPTF-0.1 J, 200 Hz, SP; Ho:YAG-0.3 J, 70 Hz, LP) and fragmenting (0.8 J, 8 Hz, SP for both) settings for 5 s. Fifteen repetitions were recorded for each laser at each setting. Tissue samples of the ureter were collected for histological analysis. RESULTS: There was a rise in temperature at the site of lithotripsy using both systems at every setting evaluated. The median temperatures were greater for the SPTF on the fragmenting setting (33.3 °C vs 30.0 °C, p = 0.004). On the dusting setting, the median temperature was not statistically greater for Ho:YAG (40.6 °C vs 35.8 °C, p = 0.064), (Graphic 1). Histological analysis did not show any signs of injury or necrosis in any of the tested settings. CONCLUSION: Higher power settings used for dusting have a higher temperature rise in the ureter during lasering. Median ureteral intra-luminal temperature rise during LL was equivalent during dusting and higher in the SPTF during fragmentation, but neither reached the threshold for thermal injury based on the duration of exposure.

A Randomized Controlled Trial of Preoperative Prophylactic Antibiotics for Percutaneous Nephrolithotomy in Moderate to High Infectious Risk Population: A Report from the EDGE Consortium.

PURPOSE: Postoperative infectious related complications are not uncommon after percutaneous nephrolithotomy. Previously, we noted that 7 days of antibiotics did not decrease sepsis rates compared to just perioperative antibiotics in a low risk percutaneous nephrolithotomy population. This study aimed to compare the same regimens in individuals at moderate to high risk for sepsis undergoing percutaneous nephrolithotomy. MATERIALS AND METHODS: Patients were prospectively randomized in this multi-institutional study to either 2 days or 7 days of preoperative antibiotics. Enrolled patients had stones requiring percutaneous nephrolithotomy and had either a positive preoperative urine culture or existing indwelling urinary drainage tube. Primary outcome was difference in sepsis rates between the groups. Secondary outcomes included rate of nonseptic bacteriuria, stone-free rate and length of stay. RESULTS: A total of 123 patients at 7 institutions were analyzed. There was no difference in sepsis rates between groups on univariate analysis. Similarly, there were no differences in nonseptic bacteriuria, stone-free rate and length of stay. On multivariate analysis, 2 days of antibiotics increased the risk of sepsis compared to 7 days of antibiotics (OR 3.1, 95% CI 1.1-8.9, p=0.031). Patients receiving antibiotics for 2 days had higher rates of staghorn calculus than the 7-day group (58% vs 32%, p=0.006) but post hoc subanalysis did not demonstrate increased sepsis in the staghorn only group. CONCLUSIONS: Giving 7 days of preoperative antibiotics vs 2 days decreases the risk of sepsis in moderate to high risk percutaneous nephrolithotomy patients. Future guidelines should consider infectious risk stratification for percutaneous nephrolithotomy antibiotic recommendations.

Device profile of the LithoVue single-use digital flexible ureteroscope in the removal of kidney stones: overview of safety and efficacy.

Introduction: Flexible ureteroscopy is a commonly performed urologic procedure for visualization and treatment of the upper urinary tracts. Traditionally, ureteroscopy has been performed with reusable scopes, which have large initial purchasing costs. LithoVue was the first widely adopted single-use flexible ureteroscope clinically available in 2016 and has caused reevaluation of this paradigm. Areas covered: This review is an objective assessment of the LithoVue single-use ureteroscope based on available studies at the time of publication. The authors searched major databases for papers that included the term 'LithoVue' and included relevant papers. The state of the market, technical specifications, results from clinical studies and cost analyses, and competitors are discussed. Expert opinion: The LithoVue single-use flexible ureteroscope has comparable clinical performance to existing reusable ureteroscopes based on available data. Direct clinical comparisons to competing single-use ureteroscopes, many of which are relatively new, are limited. In numerous pre-clinical studies LithoVue performed favorably compared to available competitors. Cost analyses suggest that benefit of single-use ureteroscopes is institution-specific, and will likely be favorable at a low volume of cases and with high local costs for repairs of reusable scopes.

Trends in Acute Pain Management for Renal Colic in the Emergency Department at a Tertiary Care Academic Medical Center.

Introduction: Renal colic secondary to kidney stone disease is a common reason for emergency department (ED) visits and often leads to patients receiving narcotic medications. The objective of this study was to describe longitudinal analgesia prescribing patterns for kidney stone patients acutely managed in the ED. Methods: This was a retrospective chart review of patients who presented to the ED between 2013 and 2018 and were subsequently diagnosed with a kidney stone. Encounters during which opioids and nonopioids were administered in the ED and prescribed at discharge were stratified by year, race, ethnicity, insurance status, gender, and location of ED (main academic campus and community-based campus). Patients were excluded if they required hospital admission or a stone-related procedure related to the ED encounter. Results: We reviewed 1620 total encounters for 1376 unique patients. Frequency of patients receiving opioids in the ED decreased from 81% in 2013 to 57% in 2018 (p < 0.001). During the same time period, nonopioid administration in the ED remained relatively unchanged (64% vs 67%). The proportion of patients prescribed opioids at discharge decreased from 77% to 59% (p < 0.001), while nonopioid prescriptions at discharge increased from 32% to 41% (p = 0.010). Frequency of administering both a narcotic and non-narcotic during the same ED encounter decreased over the 5-year period from 27% to 8% (p < 0.001). Conclusion: Opioids are being given less both during the ED encounter and at discharge for acute renal colic, while nonopioid prescribing is increasing. These trends may be due to increasing physician awareness to opioid addiction, or as a result of stricter legislation prohibiting opioid prescribing.

Single-Use Grasper Integrated Flexible Cystoscope for Stent Removal: A Micro-Costing Analysis-Based Comparison.

Background: A single-use flexible cystoscope with integrated grasper (Isiris; Coloplast, Denmark) has recently become commercially available. The objective of our study is to compare the costs of stent removal in an outpatient clinical environment between the single-use Isiris system (Coloplast) to our existing approach using a reusable cystoscope and stent grasper. Materials and Methods: The number of stent removal procedures at our tertiary center was recorded as a proportion of all cystoscopic procedures performed between February 2016 and February 2017. Elements in the micro-cost assessment included original purchasing price of an Olympus digital reusable cystoscope, repair fee (based on a 1-year contract), sterilization equipment and accessory costs, reprocessing costs of the cystoscope, and labor costs. The costs were estimated on a per-use basis and compared to the purchasing price of Isiris. Results: A total of 1775 cystoscopic procedures were performed, and the reusable cystoscope was used for stent removal in 871 (49%) cases. The per-use cost for stent removal procedures using the reusable cystoscope was estimated to be $161.85. The single per-use purchasing price for the Isiris device is $200. Based on the current volume, the break-even point was calculated to be 704 stent pulls. After 704 stent pulls, the cost benefit favors the reusable cystoscope. Conclusion: Based on this micro-cost analysis, per-use costs appear to favor the reusable cystoscope for stent removal. It appears that centers with high volumes of stent pulls may find the reusable cystoscope and stent grasper more cost beneficial than the single-use system.

The Impact of Ureteral Access Sheath Use on the Development of Abnormal Postoperative Upper Tract Imaging after Ureteroscopy.

PURPOSE: Ureteral access sheaths are commonly used during ureteroscopy to facilitate stone removal, improve visibility and maintain low intrarenal pressures. However, the use of a ureteral access sheath can cause ureteral wall ischemia and ureteral tears, potentially increasing the risk of postoperative ureteral stricture and obstruction. We studied the impact of ureteral access sheath use on postoperative imaging studies. Secondary objectives included studying the impact of other intraoperative parameters on postoperative imaging studies. MATERIALS AND METHODS: A retrospective chart review was conducted of cases that underwent ureteroscopy for nephroureterolithiasis across 2 high volume institutions between January 2012 and September 2016. Patient demographics, cumulative stone size, operative time, use of ureteral access sheath, laser lithotripsy, basket extraction, preoperative ureteral stent and postoperative ureteral stent placement were extracted from the electronic medical record. Findings of followup renal ultrasound, kidney-ureter-bladder x-ray and/or computerized tomography at approximately 8 weeks after surgery were recorded. RESULTS: A total of 1,332 ureteroscopies were performed with 1,060 cases (79.6%) returning for routine upper tract imaging after ureteroscopy. Postoperative hydronephrosis was noted following 127 cases (12.0%). Factors predicting presence of hydronephrosis after ureteroscopy include lower body mass index (p=0.0016), greater cumulative stone size (p=0.0003), increased operative time (p <0.0001), preoperative ureteral stent (OR 1.49, p=0.0299) and postoperative ureteral stent placement (OR 6.43, p=0.0031). Postoperative hydronephrosis was not associated with use of ureteral access sheath, age, laser lithotripsy or basket extraction. CONCLUSIONS: Use of ureteral access sheath did not have a significant impact on development of postoperative hydronephrosis, suggesting ureteral access sheath is safe for use during ureteroscopy. Ureteral strictures remain rare following ureteroscopy, seen in only 1.0% of our cohort. With an observed prevalence of hydronephrosis of 12.0% on followup imaging at 8 weeks, routine upper tract imaging after ureteroscopy remains a valuable prognostic tool.

Outcomes of Conservative Management of Splenic Injury Incurred During Percutaneous Nephrolithotomy.

Purpose: Splenic injury is a rare complication after left-sided percutaneous nephrolithotomy (PCNL). Although initial observation is often espoused, the natural history of nonoperative conservative management is not well established and the implications of splenic injury are not fully defined in this context. We sought to describe outcomes of conservative management of splenic injury incurred at PCNL. Patients and Methods: We performed a multi-institutional retrospective review of individual patients who underwent PCNL complicated by trans-splenic nephrostomy access injury. Demographic info, intraoperative data, management strategies, and outcomes were reviewed. Results: Nine patients suffered splenic injury after left PCNL. All patients had supracostal upper pole access under fluoroscopic guidance. Splenic injury was identified by computed tomography (CT) in the eight of nine (89%) who had imaging on first postoperative day. All eight patients were managed conservatively with nephrostomy dwell time of 2-21 days, one of whom (11%) required blood transfusion. The remaining patient (11%)-who had tubeless PCNL without postoperative imaging presented 5 days postoperatively with a delayed bleed and underwent emergent splenectomy. Seven of the nine (78%) were managed nonoperatively and without need for transfusion or embolization. Conclusion: The majority of patients incurring splenic injury during PCNL can be managed conservatively with maintenance of nephrostomy tube for ≥2 days. Consequences of unrecognized splenic injury may include splenic bleed and may prompt transfusion and/or splenectomy, underscoring role of routine postoperative CT to allow timely diagnosis, particularly in those undergoing upper pole supracostal left-sided percutaneous renal access.

The microbiome of calcium-based urinary stones.

Historically, the role of bacteria in urinary stone disease (USD) has been limited to urease-producing bacteria associated with struvite stone formation. However, growing evidence has revealed bacteria associated with stones of non-struvite composition. These bacteria may be derived from either urine or from the stones themselves. Using 16S rRNA gene sequencing and an enhanced culture technique (EQUC), we identified the urine and stone microbiota of USD patients and then determined if bacteria were statistically enriched in the stones relative to the urine. From 52 patients, bladder urine and urinary stones were collected intraoperatively during ureteroscopy. Stone homogenate and urine specimens were subjected to 16S rRNA gene sequencing and EQUC. Standard Chi-squared tests were applied to determine if the relative abundance of any bacterial taxon was significantly enriched in urinary stones compared to urine. Stones were primarily calcium-based. 29/52 (55.8%) stones had bacteria detected by 16S rRNA gene sequencing. Of these, dominant bacterial taxa were enriched from 12 stones. Bacterial taxa isolated by EQUC include members of the genera Staphylococcus, Enterobacter, Escherichia, Corynebacterium, and Lactobacillus. Dominant bacterial genera were enriched compared to paired bladder urine. Differences between the stone and urine microbiota may indicate that certain bacteria contribute to USD pathophysiology. Further investigation is warranted.

Are We Cutting Ourselves Short? Laser Lithotripsy Performance Based on Differences in Fiber-tip Preparation.

OBJECTIVE: To better understand the impact of laser fiber-tip configuration on lithotripsy performance, we undertook an in vitro study comparing 3 fiber-tip configurations: (1) new (single-use), (2) cleaved (reusable), and (3) coated (cut with scissors). METHODS: Lithotripsy was performed using a Ho:YAG laser utilizing fragmentation (1 J × 10 Hz) and dusting (0.5 J × 20 Hz) settings. BegoStones were fragmented with a laser fiber advancing at a speed of 1 mm/s (220 seconds of activation). Three fiber-tip configurations were tested: new single-use standard (242 µm core) and cleaved (272 µm core), compared to the same fiber-tip coated/cut flush with scissors, respectively. Study outcome was difference in stone mass before and after each experiment. Power output was measured using a power meter. RESULTS: Fragmentation for new or cleaved fibers was greater than the coated/cut flush fiber-tip (P <.05). For 1 J × 10 Hz and 0.5 J × 20 Hz settings, fragmentation was 59% and 75% higher with new fiber-tip compared to the coated/cut flush fiber-tip, respectively. For 1J × 10 Hz and 0.5 J × 20 Hz settings, fragmentation was 51% and 45% higher with cleaved fiber-tip compared to the coated/cut flush fiber-tip, respectively. Power output at the end of laser activation was higher for new and cleaved fiber-tips. CONCLUSION: New and cleaved laser fibers demonstrated superior lithotripsy performance compared to fibers that were coated/cut flush with scissors. Cutting single-use laser fibers risks damaging the fiber-tip which can disperse the energy and reduce lithotripsy efficiency.