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.

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.

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.

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.

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.

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.

Holmium-YAG laser: impact of pulse energy and frequency on local fluid temperature in an in-vitro obstructed kidney calyx model.

During laser lithotripsy, energy is transmitted to both the stone and the surrounding fluid. As the energy is delivered, the temperature will rise. Temperatures ≥60 ° C can cause protein denaturation. The objective of this study is to determine the time it takes from body temperature (37°C) to 60°C at various laser power settings. A Flexiva TracTip 200 optical fiber was submerged alongside a negative temperature coefficient-type thermistor in 4 mL of saline in a glass test tube. A Lumenis VersaPulse Powersuite 100-W holmium:yttrium aluminum garnet laser was activated at 0.2- to 1.5-J pulse energies, 6- to 50-Hz frequencies, and 2- to 22.5-W average power. Temperature readings were recorded every second from 37°C until 60°C. Time and heating rate were measured. The procedure was repeated three times for each setting. Average time from 37°C to 60°C for settings (1) 0.2 J/50 Hz, (2) 0.6 J/6 Hz, (3) 1 J/10 Hz, and (4) 1.5 J/10 Hz was 60.3, 172.7, 58, and 43.3 s, respectively. Time from 37°C to 60°C decreased as frequency increased for every given pulse energy. Average heating rate increased proportionally to power from 0.06°C/s at 2 W to 0.74°C/s at 22.5 W. During laser lithotripsy, there is a rapid increase in the temperature of its surrounding fluid and temperatures ≥60 ° C may be reached. This could have local tissue effects and some caution with higher power settings should be employed especially where irrigation is limited. Further studies incorporating irrigation and live tissue models may aid to further define the risks.

Ureteroscopic Laser Lithotripsy: A Review of Dusting vs Fragmentation with Extraction.

INTRODUCTION: Ureteroscopic laser lithotripsy is becoming the most commonly utilized treatment for patients with urinary calculi. The Holmium:YAG (yttrium aluminum garnet) laser is integral to the operation and is the preferred flexible intracorporeal lithotrite. In recent years, there has been increasing interest in examining the effect of varying the laser settings on the effectiveness of stone treatment. Herein, we review the two primary laser treatment approaches: dusting and fragmentation with extraction. METHODS: We reviewed PubMed and MEDLINE databases from January 1976 through January 2017. All authors participated in the development of consensus definitions of dusting and fragmentation with extraction. The review protocol adhered to preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology. RESULTS: When the Holmium:YAG laser is used to treat stones, there are two parameters that can be adjusted: power (J) and frequency (Hz). In one treatment paradigm, which became termed "fragmentation with extraction," laser settings that relied on high energy and low frequency were used. Another paradigm, which became termed "dusting," utilized low energy and high frequency settings, which had the effect of breaking off exceedingly small fragments from the stone. CONCLUSIONS: Both dusting and fragmentation with extraction approaches to ureteroscopic stone treatment are effective. In fact, there is little evidence that one approach is better than the other. However, each does have relative advantages and disadvantages, which should be considered. Although dusting tends to be associated with shorter procedure times and a lower risk of ureteral damage, this approach may place the patient at increased risk for future stone events should all of the resultant debris not be expelled from the collecting system. The active removal associated with fragmentation with extraction, in contrast, may provide for a more complete initial stone clearance.

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.

Ureteroscopy: accessory devices.

The incidence of stone disease continues to rise. Surgical management options including shockwave laser lithotripsy, percutaneous nephrolithotomy, and ureteroscopy with stone extraction and/or lithotripsy. The technology associated with the ureteroscopic treatment of stones has advanced significantly over the past decade and this review focuses on many of the accessory devices that can be employed to aid in the procedure.

Crowd-Sourced Assessment of Technical Skills for Validation of Basic Laparoscopic Urologic Skills Tasks.

PURPOSE: The BLUS (Basic Laparoscopic Urologic Skills) consortium sought to address the construct validity of BLUS tasks and the wider problem of accurate, scalable and affordable skill evaluation by investigating the concordance of 2 novel candidate methods with faculty panel scores, those of automated motion metrics and crowdsourcing. MATERIALS AND METHODS: A faculty panel of surgeons (5) and anonymous crowdworkers blindly reviewed a randomized sequence of a representative sample of 24 videos (12 pegboard and 12 suturing) extracted from the BLUS validation study (454) using the GOALS (Global Objective Assessment of Laparoscopic Skills) survey tool with appended pass-fail anchors via the same web based user interface. Pre-recorded motion metrics (tool path length, jerk cost etc) were available for each video. Cronbach's alpha, Pearson's R and ROC with AUC statistics were used to evaluate concordance between continuous scores, and as pass-fail criteria among the 3 groups of faculty, crowds and motion metrics. RESULTS: Crowdworkers provided 1,840 ratings in approximately 48 hours, 60 times faster than the faculty panel. The inter-rater reliability of mean expert and crowd ratings was good (α=0.826). Crowd score derived pass-fail resulted in 96.9% AUC (95% CI 90.3-100; positive predictive value 100%, negative predictive value 89%). Motion metrics and crowd scores provided similar or nearly identical concordance with faculty panel ratings and pass-fail decisions. CONCLUSIONS: The concordance of crowdsourcing with faculty panels and speed of reviews is sufficiently high to merit its further investigation alongside automated motion metrics. The overall agreement among faculty, motion metrics and crowdworkers provides evidence in support of the construct validity for 2 of the 4 BLUS tasks.

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.

Validation of the AUA BLUS Tasks.

PURPOSE: Standardized assessment of laparoscopic skill in urology is lacking. We investigated whether the AUA (American Urological Association) BLUS (Basic Laparoscopic Urologic Skills) skill tasks are valid to address this need. MATERIALS AND METHODS: This institutional review board approved study included 27 medical students, 42 urology residents, 18 fellows and 37 faculty urologists across 8 sites. Using the EDGE (Electronic Data Generation and Evaluation) device (Simulab, Seattle, Washington) 454 recordings were collected on peg transfer, pattern cutting, suturing and clip applying tasks, which together comprise the expert determined BLUS tasks. We collected synchronized video and tool motion data for each trial. For each task errors, time, path length, economy of motion, peak grasp force and EDGE score were collected. An expert panel of 5 faculty members performed GOALS (Global Objective Assessment of Laparoscopic Skills) evaluations on a representative subset of peg transfer and suturing skill tasks performed by 24 participants (IRR = 0.95). RESULTS: Demographically derived skill levels proved unsuitable to evaluate construct validity. Separation of mean scores by grouped skill levels was strongest for the suturing task. Objective motion metrics and errors supported construct validity vis-à-vis correlation with blinded expert video ratings (motion metrics R(2) = 0.95, p <0.01). Expert scores appeared to reward errors in suturing but not in block transfer. CONCLUSIONS: BLUS skill task performance scoring can discriminate among basic laparoscopic technical skill levels. Self-reported demographics are an unreliable source of determining laparoscopic technical skill.

Desflurane Allows for a Faster Emergence When Compared to Sevoflurane without Affecting the Baseline Cognitive Recovery Time.

AIMS: We compared the effect of desflurane and sevoflurane on anesthesia recovery time in patients undergoing urological cystoscopic surgery. The Short Orientation-Memory-Concentration Test (SOMCT) measured and compared cognitive impairment between groups and coughing was assessed throughout the anesthetic. METHODS AND MATERIALS: This investigation included 75 ambulatory patients. Patients were randomized to receive either desflurane or sevoflurane. Inhalational anesthetics were discontinued after removal of the cystoscope and once repositioning of the patient was final. Coughing assessment and awakening time from anesthesia were assessed by a blinded observer. STATISTICAL ANALYSIS USED: Statistical analysis was performed by using t-test for parametric variables and Mann-Whitney U test for non-parametric variables. RESULTS: The primary endpoint, mean time to eye-opening, was 5.0 ± 2.5 min for desflurane and 7.9 ± 4.1 min for sevoflurane (p < 0.001). There were no significant differences in time to SOMCT recovery (p = 0.109), overall time spent in the post-anesthesia care unit (PACU) (p = 0.924) or time to discharge (p = 0.363). Median time until readiness for discharge was 9 min in the desflurane group, while the sevoflurane group had a median time of 20 min (p = 0.020). The overall incidence of coughing during the perioperative period was significantly higher in the desflurane (p = 0.030). CONCLUSION: We re-confirmed that patients receiving desflurane had a faster emergence and met the criteria to be discharged from the PACU earlier. No difference was found in time to return to baseline cognition between desflurane and sevoflurane.

Evaluation of 16 New Holmium:Yttrium-Aluminum-Garnet Laser Optical Fibers for Ureteroscopy.

OBJECTIVE: To test the performance of 16 new single-use holmium:yttrium-aluminum-garnet (YAG) laser fibers. MATERIALS AND METHODS: Small and medium core fibers were evaluated for flexibility, true diameter, connector temperature, and failure threshold. A flexible ureteroscope was deflected with the fiber in the working channel to measure flexibility. Diameter was measured by micrometer and connector temperature by infrared thermometer. Failure threshold was determined by bending the fiber to 180°, beginning with a radius of 1.25 cm. A 100 W holmium:YAG laser was operated at 1.2 J/10 Hz for 30 seconds or until fiber fracture. The radius was decreased in 0.25-cm increments until a minimum bend radius of 0.4 cm was attained or until fiber fracture. RESULTS: Of the small core-fibers, the Cook-HLF-S150 (Cook Medical) had the smallest diameter and the Flexiva TracTip 200 (Boston Scientific) the largest. The Cook-HLF-S150 and S200 were the most flexible and the SlimLine EZ200 (Lumenis) the least. The SlimLine EZ200 failed at the largest bend radius, whereas the Flexiva 200 and Flexiva TracTip 200 did not fracture. Of the medium-core fibers, the ScopeSafe 300 had the smallest diameter and the Flexiva 365 the largest. The ScopeSafe 300 was the most flexible and the SlimLine 365 the least. The ScopeSafe 365 failed at the largest radius of 1.25 cm, and the Flexiva 365 did not fail in 6 of 9 trials at the tightest radius. CONCLUSION: Performance characteristics of these new holmium:YAG optical fibers differed significantly but performance was on par or better than historical controls.