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.

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.

Medical dissolution therapy for the treatment of uric acid nephrolithiasis.

INTRODUCTION: Uric acid (UA) nephrolithiasis represents 10% of kidney stones in the US with low urine pH and high saturation of UA as the main risk factors for stone development. Dissolution therapy for UA kidney stones via urinary alkalization has been described as a treatment option. We present our experience in treating UA nephrolithiasis with medical dissolution therapy. METHODS: A retrospective review was performed of UA stone patients referred for surgery but treated with dissolution therapy between July 2007 and July 2016. Patients were identified using ICD-9 codes. Patients were treated with potassium citrate alone or in combination with allopurinol. Serial imaging and urine pH were obtained at follow-up. Demographics, aggregate stone size, time to stone clearance, urine pH (office dip), and complications were recorded. RESULTS OBTAINED: Twenty-four patients (14 men and 10 women) were identified that started medical dissolution therapy for UA nephrolithiasis after initial referral for surgical management. Three patients (13%) did not tolerate the initiation of dissolution therapy and discontinued this treatment. Of the 21 patients that were maintained on dissolution therapy, 14 patients (67%) showed complete resolution of nephrolithiasis and 7 patients (33%) showed partial reduction. Patients with partial response had a mean reduction in stone burden of 68%. There were 3 recorded complications (UTI, GI upset with therapy, and throat irritation) and 4 recorded stone recurrences among these 21 patients. CONCLUSION: Based on our study population, medical dissolution therapy is a well-tolerated, non-invasive option for UA nephrolithiasis.

Supracostal access tubeless percutaneous nephrolithotomy: minimizing complications.

INTRODUCTION AND OBJECTIVE: Supracostal access in percutaneous nephrolithotomy (PCNL) may be avoided due to concern for thoracic complications. The objective of the study is to report the safety and efficacy of supracostal access utilizing a tubeless (stent only) PCNL technique. PATIENTS AND METHODS: Retrospective review of perioperative outcomes of 70 patients (76 renal units) who underwent a supracostal tubeless PCNL. No nephrostomy tubes were left. All patients had a 7F ureteral stent and Foley catheter placed. The nephrostomy sheath was removed with the patient held in end-expiration, and the incision closed. RESULTS: Median (IQR) age was 62 (48.3-67) years. Median stone size was 20 × 21 mm, and 14 (18%) patients had complete staghorn stones. The upper calyx was the site of access in 52 (68.4%) cases. Access was above the 12th and 11th rib in 63 (83%) and 12 (16%) cases, respectively. Median (IQR) length of stay was 30 (28-32) hours. Fifty (68.5%) patients had no residual fragments (< 2 mm) on postoperative imaging. Eight (11%) patients underwent an ancillary procedure (7 URS and 1 ESWL), with an additional seven patients becoming stone free after this procedure (78%). Thoracic complications occurred in two (2.6%) patients: one small pneumothorax, and one pleural effusion, both managed conservatively. Other complications occurred in nine patients (11.8%): bleeding requiring transfusion (1), fever (4), urinary retention (2), and syncope (2). CONCLUSION: Compared to historical controls, our approach to upper tract PCNL utilizing a nephrostomy tube-free approach resulted in an overall low thoracic complication rate and facilitated hospital discharge.

Dusting versus Basketing during Ureteroscopy-Which Technique is More Efficacious? A Prospective Multicenter Trial from the EDGE Research Consortium.

PURPOSE: There is scant evidence in the literature to support dusting vs active basket extraction during ureteroscopy for kidney stones. We prospectively evaluated and followed patients to determine which modality produced a higher stone-free rate with the fewest complications. MATERIALS AND METHODS: Members of the Endourologic Disease Group for Excellence research consortium prospectively enrolled patients with a renal stone burden ranging from 5 to 20 mm in this study. A holmium laser was used and all patients were stented postoperatively. Ureteral access sheaths were used in 100% of basketing cases while sheaths were optional when dusting. The primary study outcome was the stone-free rate at 6 weeks as determined by x-ray and ultrasound. RESULTS: A total of 84 and 75 patients were enrolled in the basketing and dusting arms, respectively. Stones in the dusting group were significantly larger (mean ± SD stone area 96.1 ± 65.3 vs 63.3 ± 46.0 mm2, p <0.001). The stone-free rate was significantly higher in the basketing group on univariate analysis (74.3% vs 58.2%, p = 0.04) but not on multivariate analysis (1.9 OR, 95% CI 0.9-4.3, p = 0.11). In patients who underwent a basketing procedure operative time was 37.7 minutes longer than in those treated with a dusting procedure (95% CI 23.8-51.7, p <0.001). There was no statistically significant difference in complication rates, hospital readmissions or additional procedures between the groups. CONCLUSIONS: The stone-free rate was higher for active basket retrieval of fragments at short-term followup on univariate analysis but not on multivariate analysis. There was no difference in postoperative complications or procedures. The 2 techniques should be in the armamentarium of the urologist.

Natural History, Complications and Re-Intervention Rates of Asymptomatic Residual Stone Fragments after Ureteroscopy: a Report from the EDGE Research Consortium.

PURPOSE: Fragments 4 mm or smaller after ureteroscopy historically have been considered clinically insignificant but there is a reported 20% event rate on followup even with stones 4 mm or smaller. In this study we examine the natural history, complications and re-intervention rates of fragments after ureteroscopy. MATERIALS AND METHODS: Data from 6 centers were collected retrospectively from members of the Endourology Disease Group for Excellence in 232 patients who had residual fragments after ureteroscopy between 2006 and 2013. Patients with fragment(s) of any size on imaging within 12 months were eligible. The primary outcome measured was stone events, and secondary outcomes included stone growth, stone passage, re-intervention and complications. RESULTS: Of the 232 subjects with fragments 131 (56%) required no further intervention and remained asymptomatic, 34 (15%) experienced complications requiring no intervention and 67 (29%) required intervention, ie the primary outcome stone event rate was 44%. Fragments larger than 4 mm were more likely to grow with time (p <0.001) and were associated with more complications (p=0.039). Fragments larger than 2 mm were more likely to grow (p <0.001) but were not associated with complications or re-intervention. Re-intervention was predictable based on fragment size (p=0.017). In a multivariable logistic regression model there was no significant difference between the techniques of dusting stones or basket extraction. CONCLUSIONS: This study suggests that fragment size larger than 4 mm after ureteroscopy is associated with significantly higher rates of stone growth, complications and the need for re-intervention. Ensuring complete stone-free status is the most effective strategy to reduce stone events after ureteroscopy.

Optimizing use of the holmium:YAG laser for surgical management of urinary lithiasis.

The holmium:yttrium aluminum garnet (Ho:YAG, holmium) laser is an intracorporeal lithotrite that is widely used in the surgical management of urinary lithiasis. The Ho:YAG laser is capable of fragmenting urinary stones of all compositions while maintaining a wide margin of safety. The 2140-nm wavelength of energy is transmitted from the generator to the stone using specialized silica optical fibers. The effectiveness of the laser can be impacted by the type of laser fiber used, the pulse energy and frequency settings, and the composition of the stone. This paper provides an overview of Ho:YAG laser fibers utilized for lithotripsy during ureteroscopy. We will also review current data regarding optimal energy settings and discuss our experience with different fragmentation techniques.

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.

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.

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).

Durability of reusable holmium:YAG laser fibers: a multicenter study.

PURPOSE: Single use and reusable variants of holmium:YAG laser fibers are available to treat calculi during ureteroscopic procedures. In this prospective, multicenter study we evaluated a series of reusable holmium:YAG laser optical fibers. We hypothesized that reusable fibers provide a cost advantage over single use variants. MATERIALS AND METHODS: We prospectively recorded fiber data, including type, size, number of uses, laser pulse energy and frequency, and total energy delivered. All fibers were new and purchased off the shelf by staff at each institution. We performed a cost analysis comparing reusable fibers to single use variants. RESULTS: During 541 procedures a total of 37 holmium:YAG optical laser fibers were used, including 21 Laser Peripherals 270 (Laser Peripherals, Golden Valley, Minnesota), 7 Laser Peripherals 365, 4 Lumenis SlimLine™ 200 and 3 Lumenis SlimLine 365 fibers. After stratifying by core size 365 µm core fibers had significantly more uses than 270 µm core fibers (average 23.5 vs 11.3, p < 0.02). By fiber type the mean ± SE number of uses was 12.8 ± 2.44, 3 ± 0.4, 21.3 ± 7.12 and 28.7 ± 6.69 for the Laser Peripheral 270, Lumenis SlimLine 200, Laser Peripherals 365 and Lumenis SlimLine 365, respectively. The total cost savings for reusable fibers vs single use variants was $64,125. CONCLUSIONS: Reusable holmium:YAG optical laser fibers are a more cost-effective option than single use variants. Fibers with a 365 µm core provide more uses than smaller 270 µm variants.

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.

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.

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.

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.

Evaluation of 24 holmium:YAG laser optical fibers for flexible ureteroscopy.

PURPOSE: Prior study has shown that holmium:YAG laser fiber performance differs among manufacturers. We determined the performance and threshold for failure of 24 commercially available holmium:YAG laser fibers. MATERIALS AND METHODS: Single use and reusable fibers were tested in small (150 to 300 microm) and medium (300 to 400 microm) core diameter sizes. All fibers were evaluated for flexibility, failure threshold and true fiber diameter. Flexibility was measured by maximally deflecting a Stryker U-500 ureteroscope with the fiber in the working channel. The diameter of each fiber was measured by a digital micrometer. The failure threshold was assessed by bending the fibers to 180 degrees, beginning with a radius of 1.25 cm. A VersaPulse 100 W holmium:YAG laser was operated at 1.2 J and 10 Hz for 1 minute or until fiber fracture. The bend radius was decreased in 0.25 cm increments and testing was repeated until a minimum bend radius of 0.5 cm was attained or until the fiber failed. RESULTS: Of the small core fibers the SureFlex LLF-150 and LLF-273, OptiLite SMH1020F and Dornier LG Super 270 had the highest threshold for failure. The Accuflex 200 had the lowest failure threshold failing at the largest bend radius (1.75 cm). Of the medium core fibers the SureFlex LLF-365, Accuflex 365 and Lumenis SL 365 had the highest failure threshold, while the Dornier LG 400 and Lumenis EZ SL 365 were the lowest. The reusable Lumenis 365 fiber had a higher failure threshold than the single use Lumenis 365 fiber. CONCLUSIONS: Commercially available holmium:YAG laser fibers differ significantly in their performance characteristics.

Laser Fibers for Holmium:YAG Lithotripsy: What Is Important and What Is New.

Holmium:YAG laser is currently the dominant lithotripter used during retrograde intrarenal surgery. The laser energy is delivered to the target via flexible optical laser fibers. The performance characteristics of laser fibers vary. The diameter, flexibility, resistance to fracture with bending, and tip configuration are all important factors that contribute to a fiber's overall performance. Understanding these characteristics assists the end user with proper fiber selection for procedures.

Reducing Fluoroscopy Time in Percutaneous Nephrolithotomy.

Introduction: Reducing fluoroscopy time (FT) during percutaneous nephrolithotomy (PCNL) is an opportunity for stewardship of ionizing radiation in stone patients. We present our initial results of a radiation reduction protocol (RRP) used during PCNL with fluoroscopy-guided access by the urologist. Materials and Methods: Retrospective chart review of all PCNL cases performed between January and October 2017, divided in two groups: pre-RRP (group 1) and post-RRP (group 2). Fluoroscopy was performed using low-dose and pulsed mode. Measures implemented to reduce FT include (1) one-spot images, (2) reliance on tactile feedback, and (3) using shorter segments of live fluoroscopy. The primary outcome was FT. Results: Eighty-nine PCNL procedures were performed in 89 patients, 45 in group 1 and 44 in group 2. Overall median (interquartile range) age, body mass index (BMI), and stone burden (largest axial diameter) was 56 (45-66) years, 31.3 (27-37.4) kg/m2, and 27.7 (19-41) mm, respectively, and were comparable in both the groups. The median (range) FT in group 1 and group 2 was 240 (56.0-916.0) and 65.5 (13.0-561.0) seconds (p < 0.0001), respectively. There was no correlation between FT and increasing BMI and stone burden. Overall stone-free rate was 57% (58% and 57% in group 1 and group 2, respectively, p = 0.5995), with 10 patients (11%) undergoing ancillary procedures. Overall and major (Clavien 3a+) complications occurred in 10 (11%) and 5 (6%) cases, respectively, in the overall cohort. Conclusion: FT in PCNL can be significantly reduced by adapting simple techniques and being increasingly vigilant of its usage, thereby reducing radiation exposure to the surgeon and the patient.

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.