The Association Between 24-Hour Urine and Stone Recurrence Among High Risk Kidney Stone Formers: A Population Level Assessment.

OBJECTIVE: To determine if obtaining a 24-hour urine collection (24HU) in stone formers is associated with decreased recurrent stone episodes. METHODS: Using the MarketScan database, adults 17-62 years old with nephrolithiasis were identified between 2007 and 2017 with a minimum of 3-year follow up. High-risk stone formers, those undergoing stone surgery, and those with history of recurrent stones were identified. The exposure was a 24HU within 6 months of primary diagnosis. The outcome was recurrent stone episodes-defined by stone-related emergency room visits, hospitalizations, or stone surgery 90 days to 3 years after diagnosis. Logistic regression was used to estimate recurrence risk by 24HU exposure for the overall cohort and sub-cohorts limited to known recurrent stone formers, high-risk subjects, and those having stone surgery. RESULTS: Of 434,055 subjects analyzed, 30,153 (6.9%) had a 24HU. An annual decline in 24HU utilization was seen (7.5%-5.8%). Regional variation in usage rate was also observed. On multivariate analysis, completing a 24HU was not associated with risk of recurrence in any of the following cohorts: recurrent stone formers (OR 0.98, 95% CI 0.9-1.07), both high risk and recurrent stone formers (OR 0.95 [0.8-1.13]), those undergoing surgery (OR 1.02 [0.97-1.07]); a positive association with 24HU and recurrence was seen in those labeled high-risk (OR 1.08 [1.01-1.16]) and in all-comers (OR 1.15 [1.12-1.19]). CONCLUSION: The 24HU was not associated with decreased recurrence rates in the overall population nor in higher risk sub-cohorts.

Quantitative Assessment of Effectiveness of Ultrasonic Propulsion of Kidney Stones.

Purpose: Ultrasonic propulsion is an investigative modality to noninvasively image and reposition urinary stones. Our goals were to test safety and effectiveness of new acoustic exposure conditions from a new transducer, and to use simultaneous ureteroscopic and ultrasonic observation to quantify stone repositioning. Materials and Methods: During operation, ultrasonic propulsion was applied transcutaneously, whereas stone targets were visualized ureteroscopically. Exposures were 350 kHz frequency, ≤200 W/cm2 focal intensity, and ≤3-second bursts per push. Ureteroscope and ultrasound (US) videos were recorded. Video clips with and without stone motion were randomized and scored for motion ≥3 mm by independent reviewers blinded to the exposures. Subjects were followed with telephone calls, imaging, and chart review for adverse events. Results: The investigative treatment was used in 18 subjects and 19 kidneys. A total of 62 stone targets were treated ranging in size from a collection of "dust" to 15 mm. Subjects received an average of 17 ± 14 propulsion bursts (per kidney) for a total average exposure time of 40 ± 40 seconds. Independent reviewers scored at least one stone movement ≥3 mm in 18 of 19 kidneys (95%) from the ureteroscope videos and in 15 of 19 kidneys (79%) from the US videos. This difference was probably because of motion out of the US imaging plane. Treatment repositioned stones in two cases that would have otherwise required basket repositioning. No serious adverse events were observed with the device or procedure. Conclusions: Ultrasonic propulsion was shown to be safe, and it effectively repositioned stones in 95% of kidneys despite positioning and access restrictions caused by working in an operating room on anesthetized subjects.

Crowd-Sourced Assessment of Technical Skills: Differentiating Animate Surgical Skill Through the Wisdom of Crowds.

BACKGROUND: Objective quantification of surgical skill is imperative as we enter a healthcare environment of quality improvement and performance-based reimbursement. The gold standard tools are infrequently used due to time-intensiveness, cost inefficiency, and lack of standard practices. We hypothesized that valid performance scores of surgical skill can be obtained through crowdsourcing. METHODS: Twelve surgeons of varying robotic surgical experience performed live porcine robot-assisted urinary bladder closures. Blinded video-recorded performances were scored by expert surgeon graders and by Amazon's Mechanical Turk crowdsourcing crowd workers using the Global Evaluative Assessment of Robotic Skills tool assessing five technical skills domains. Seven expert graders and 50 unique Mechanical Turkers (each paid $0.75/survey) evaluated each video. Global assessment scores were analyzed for correlation and agreement. RESULTS: Six hundred Mechanical Turkers completed the surveys in less than 5 hours, while seven surgeon graders took 14 days. The duration of video clips ranged from 2 to 11 minutes. The correlation coefficient between the Turkers' and expert graders' scores was 0.95 and Cronbach's Alpha was 0.93. Inter-rater reliability among the surgeon graders was 0.89. CONCLUSION: Crowdsourcing surgical skills assessment yielded rapid inexpensive agreement with global performance scores given by expert surgeon graders. The crowdsourcing method may provide surgical educators and medical institutions with a boundless number of procedural skills assessors to efficiently quantify technical skills for use in trainee advancement and hospital quality improvement.

Quantitative assessment of shockwave lithotripsy accuracy and the effect of respiratory motion.

BACKGROUND AND PURPOSE: Effective stone comminution during shockwave lithotripsy (SWL) is dependent on precise three-dimensional targeting of the shockwave. Respiratory motion, imprecise targeting or shockwave alignment, and stone movement may compromise treatment efficacy. The purpose of this study was to evaluate the accuracy of shockwave targeting during SWL treatment and the effect of motion from respiration. PATIENTS AND METHODS: Ten patients underwent SWL for the treatment of 13 renal stones. Stones were targeted fluoroscopically using a Healthtronics Lithotron (five cases) or Dornier Compact Delta II (five cases) shockwave lithotripter. Shocks were delivered at a rate of 1 to 2 Hz with ramping shockwave energy settings of 14 to 26 kV or level 1 to 5. After the low energy pretreatment and protective pause, a commercial diagnostic ultrasound (US) imaging system was used to record images of the stone during active SWL treatment. Shockwave accuracy, defined as the proportion of shockwaves that resulted in stone motion with shockwave delivery, and respiratory stone motion were determined by two independent observers who reviewed the ultrasonographic videos. RESULTS: Mean age was 51 ± 15 years with 60% men, and mean stone size was 10.5 ± 3.7 mm (range 5-18 mm). A mean of 2675 ± 303 shocks was delivered. Shockwave-induced stone motion was observed with every stone. Accurate targeting of the stone occurred in 60% ± 15% of shockwaves. CONCLUSIONS: US imaging during SWL revealed that 40% of shockwaves miss the stone and contribute solely to tissue injury, primarily from movement with respiration. These data support the need for a device to deliver shockwaves only when the stone is in target. US imaging provides real-time assessment of stone targeting and accuracy of shockwave delivery.

Pediatric robot-assisted laparoscopic varicocelectomy.

PURPOSE: We determined the feasibility and safety of robot-assisted laparoscopic varicocelectomy (RALV) in the pediatric population compared with laparoscopic varicocelectomy (LV). PATIENTS AND METHODS: We identified all patients who underwent RALV since April of 2006. For each case, we selected two age-matched controls who underwent LV and compared the groups in terms of operative times, postoperative complications, and hospital charges. Statistics were determined using the Student t test and the Fisher exact test. RESULTS: Four patients underwent RALV with a mean age of 15.3 years (standard deviation 1.3). All varicoceles were left-sided. Two patients had testicular size discrepancy at presentation (mean 24%). Mean operative times were 112 minutes for RALV vs 73 minutes for LV (P = 0.02). No intraoperative or postoperative complications were experienced in the RALV group. The mean total hospital charge-including facility, equipment, anesthesiology, and recovery room fees, but excluding surgeon's professional fees-was significantly higher for the robot-assisted group ($15,800 vs $8,600, P = 0.0005). CONCLUSION: We report the first RALV in a pediatric patient population. We demonstrate that it is technically feasible with no intraoperative complications. It remains to be seen whether RALV is cost effective over LV.