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PURPOSE: Our goal was to test transcutaneous focused ultrasound in the form of ultrasonic propulsion and burst wave lithotripsy to reposition ureteral stones and facilitate passage in awake subjects. MATERIALS AND METHODS: Adult subjects with a diagnosed proximal or distal ureteral stone were prospectively recruited. Ultrasonic propulsion alone or with burst wave lithotripsy was administered by a handheld transducer to awake, unanesthetized subjects. Efficacy outcomes included stone motion, stone passage, and pain relief. Safety outcome was the reporting of associated anticipated or adverse events. RESULTS: Twenty-nine subjects received either ultrasonic propulsion alone (n = 16) or with burst wave lithotripsy bursts (n = 13), and stone motion was observed in 19 (66%). The stone passed in 18 (86%) of the 21 distal ureteral stone cases with at least 2 weeks follow-up in an average of 3.9±4.9 days post-procedure. Fragmentation was observed in 7 of the burst wave lithotripsy cases. All subjects tolerated the procedure with average pain scores (0–10) dropping from 2.1±2.3 to 1.6±2.0 (P = .03). Anticipated events were limited to hematuria on initial urination post-procedure and mild pain. In total, 7 subjects had associated discomfort with only 2.2% (18 of 820) propulsion bursts. CONCLUSIONS: This study supports the efficacy and safety of using ultrasonic propulsion and burst wave lithotripsy in awake subjects to reposition and break ureteral stones to relieve pain and facilitate passage.

Introduction and Objective: Guidelines from the American Urological Association (AUA) and American College of Radiology (ACR) recommend that patients with suspected nephrolithiasis undergo low-dose CT of the kidney, ureter, and bladder (LD CT KUB) as opposed to higher dose conventional imaging. We hypothesized that even at institutions with established LD protocols, higher dose imaging is common. Materials and Methods: We identified four academic medical centers where LD CT KUB protocols were implemented to yield an effective dose (EDose) consistent with national guidelines. Fifty consecutive adult patients who underwent CT KUB specifically for the evaluation of nephrolithiasis were retrospectively reviewed at each site. Patient age, sex, body mass index (BMI), imaging location, and EDose (millisieverts [mSv]) were recorded. Results: Two hundred patients with a mean age of 54 years were identified. Forty-six patients (23%) underwent CT KUB with an EDose ≤4 mSv, accounting for 10% to 48% of each institution's cohort. One hundred sixteen patients had a BMI

BACKGROUND: The benefits of removing small (≤6 mm), asymptomatic kidney stones endoscopically is unknown. Current guidelines leave such decisions to the urologist and the patient. A prospective study involving older, nonendoscopic technology and some retrospective studies favor observation. However, published data indicate that about half of small renal stones left in place at the time that larger stones were removed caused other symptomatic events within 5 years after surgery. METHODS: We conducted a multicenter, randomized, controlled trial in which, during the endoscopic removal of ureteral or contralateral kidney stones, remaining small, asymptomatic stones were removed in 38 patients (treatment group) and were not removed in 35 patients (control group). The primary outcome was relapse as measured by future emergency department visits, surgeries, or growth of secondary stones. RESULTS: After a mean follow-up of 4.2 years, the treatment group had a longer time to relapse than the control group (P

Background: Ureteral stents are commonly employed after ureteroscopy to treat urinary stone disease, but the devices impose a substantial burden of stent-associated symptoms (SAS), including pain and urinary side effects. The NIDDK (National Institute of Diabetes and Digestive and Kidney Diseases) Urinary Stone Disease Research Network sought to develop greater understanding of SAS causes and severity among individuals treated ureteroscopically for ureteral or renal stones. Materials and Methods: We designed a prospective, observational cohort study comprising adolescents and adults undergoing ureteroscopic intervention for ureteral or renal stones. Participants will undergo detailed symptom assessment using validated questionnaires, a psychosocial assessment, and detailed collection of clinical and operative data. Quantitative sensory testing will be utilized to assess pain sensitization. In addition, a small cohort (∼40 individuals) will participate in semi-structured interviews to develop more granular information regarding their stent symptoms and experience. Biospecimens (blood and urine) will be collected for future research. Results: The Study to Enhance Understanding of sTent-associated Symptoms (STENTS) enrolled its first participant in March 2019 and completed nested qualitative cohort follow-up in August 2019. After a planned pause, enrollment for the main study cohort resumed in September 2019 and is expected to be completed in 2021. Conclusion: STENTS is expected to provide important insights into the mechanisms and risk factors for severe ureteral SAS after ureteroscopy. These insights will generate future investigations to mitigate the burden of SAS among individuals with urinary stone disease.

Purpose: To test the effectiveness (Participant A) and tolerability (Participant B) of urinary stone comminution in the first-in-human trial of a new technology, burst-wave lithotripsy (BWL). Materials and Methods: An investigational BWL and ultrasonic propulsion system was used to target a 7-mm kidney stone in the operating room before ureteroscopy (Participant A). The same system was used to target a 7.5 mm ureterovesical junction stone in clinic without anesthesia (Participant B). Results: For Participant A, a ureteroscope inserted after 9 minutes of BWL observed fragmentation of the stone to

Objective: Our goals were to validate stone comminution with an investigational burst wave lithotripsy (BWL) system in patient-relevant conditions and to evaluate the use of ultrasonic propulsion to move a stone or fragments to aid in observing the treatment endpoint. Materials and Methods: The Propulse-1 system, used in clinical trials of ultrasonic propulsion and upgraded for BWL trials, was used to fragment 46 human stones (5–7 mm) in either a 15-mm or 4-mm diameter calix phantom in water at either 50% or 75% dissolved oxygen level. Stones were paired by size and composition, and exposed to 20-cycle, 390-kHz bursts at 6-MPa peak negative pressure (PNP) and 13-Hz pulse repetition frequency (PRF) or 7-MPa PNP and 6.5-Hz PRF. Stones were exposed in 5-minute increments and sieved, with fragments >2 mm weighed and returned for additional treatment. Effectiveness for pairs of conditions was compared statistically within a framework of survival data analysis for interval censored data. Three reviewers blinded to the experimental conditions scored ultrasound imaging videos for degree of fragmentation based on stone response to ultrasonic propulsion. Results: Overall, 89% (41/46) and 70% (32/46) of human stones were fully comminuted within 30 and 10 minutes, respectively. Fragments remained after 30 minutes in 4% (1/28) of calcium oxalate monohydrate stones and 40% (4/10) of brushite stones. There were no statistically significant differences in comminution time between the two output settings (p = 0.44), the two dissolved oxygen levels (p = 0.65), or the two calyx diameters (p = 0.58). Inter-rater correlation on endpoint detection was substantial (Fleiss' kappa = 0.638, p

Renal colic encounters are common; in the United States alone, they represent greater than one million annual emergency department (ED) visits. Most of these stones are managed conservatively with a trial of passage. However, some lead to repeat colic episodes, secondary ED visits, increased anxiety, and increased cost. Of the 5%–10% of symptomatic stones that become lodged at the ureteropelvic junction and are larger than 5 mm, most require operative intervention. In the process of executing a NASA‐funded study of ultrasonic repositioning of kidney stones, the subject was administered fluid to dilate the collecting system, placed in Trendelenburg bed positioning, and rolled to both sides. During this process a symptomatic, obstructing 9‐mm ureteropelvic junction stone moved back into the kidney's lower pole/infundibulum and symptoms were immediately resolved. The patient remained asymptomatic for a period of 5 weeks at which point elective intervention was scheduled. This case demonstrates that ureteropelvic junction stones may be repositioned in a non‐invasive manner, turning a stone that requires urgent intervention into one that can be managed electively.

Our objective was to describe day-to-day evolution and variations in patient-reported stent-associated symptoms (SAS) in the STudy to Enhance uNderstanding of sTent-associated Symptoms (STENTS), a prospective multicenter observational cohort study, using multiple instruments with conceptual overlap in various domains.In a nested cohort of the STENTS study, the initial 40 participants having unilateral ureteroscopy (URS) and stent placement underwent daily assessment of self-reported measures using the Brief Pain Inventory short form, Patient-Reported Outcome Measurement Information System measures for pain severity and pain interference, the Urinary Score of the Ureteral Stent Symptom Questionnaire, and Symptoms of Lower Urinary Tract Dysfunction Research Network Symptom Index. Pain intensity, pain interference, urinary symptoms, and bother were obtained preoperatively, daily until stent removal, and at postoperative day (POD) 30.The median age was 44 years (IQR 29,58), and 53% were female. The size of the dominant stone was 7.5 mm (IQR 5,11), and 50% were located in the kidney. There was consistency among instruments assessing similar concepts. Pain intensity and urinary symptoms increased from baseline to POD 1 with apparent peaks in the first 2 days, remained elevated with stent in situ, and varied widely among individuals. Interference due to pain, and bother due to urinary symptoms, likewise demonstrated high individual variability.This first study investigating daily SAS allows for a more in-depth look at the lived experience after URS and the impact on quality of life. Different instruments measuring pain intensity, pain interference, and urinary symptoms produced consistent assessments of patients' experiences. The overall daily stability of pain and urinary symptoms after URS was also marked by high patient-level variation, suggesting an opportunity to identify characteristics associated with severe SAS after URS.

INTRODUCTION AND OBJECTIVE:The purpose of the study is to test whether removing small, asymptomatic stones from the kidneys of patients being treated for kidney or ureteral stones will reduce recur...

INTRODUCTION AND OBJECTIVE:Ureteral stents are often employed after ureteroscopy, and thought to impair patient quality of life. Despite this well-known impact, there has been little rigorous quali...

INTRODUCTION AND OBJECTIVE:The feasibility of ultrasonic propulsion and burst wave lithotripsy (BWL) to noninvasively reposition distal ureteral stones to facilitate passage and relieve pain was te...

INTRODUCTION AND OBJECTIVE:We report stone comminution in the first human subjects by burst wave lithotripsy (BWL), which is the transcutaneous application of focused, cyclic ultrasound pulses.METH...

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/cm(2) 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.

Purpose: Holmium laser lithotripsy is a common modality used to fragment urinary stones during ureteroscopy. Laser energy deposited during activation produces heat and potentially causes thermal bioeffects. We aimed to characterize laser-induced heating through a computational simulation. Materials and Methods: A finite-element model was developed and used to estimate temperature in the urinary tract. Axisymmetric models of laser lithotripsy in a renal calyx, the renal pelvis, and proximal ureter were created. Heat generation by laser and heat transfer were simulated under different laser powers between 5 and 40 W. Irrigation fluid flow was introduced at rates between 0 and 40 mL/min. The model was validated by comparison with previous in vitro temperature data in a test tube, then used to calculate heating and thermal dose in the three tissue models. Results: Simulated temperature rises agreed well with most in vitro experimental measurements. In tissue models, temperature rises depended strongly on laser power and irrigation rate, and to a lesser extent on location. Injurious temperatures were reached for 5–40 W laser power without irrigation, >10 W with 5 mL/min irrigation, 40 W with 15 mL/min irrigation, and were not found at 40 mL/min irrigation. Tissue injury volumes up to 2.3 cm(3) were calculated from thermal dose. Conclusions: The results suggest a numerical model can accurately simulate the thermal profile of laser lithotripsy. Laser heating is strongly dependent on parameters and may cause a substantial temperature rise in the fluid in the urinary tract and surrounding tissue under clinically relevant conditions.

Introduction: Studies suggest that the width of the acoustic shadow on ultrasound (US) more accurately reflects true stone size than the stone width in US images. We evaluated the need for training in the adoption of the acoustic shadow sizing technique by clinical providers. Methods: Providers without shadow sizing experience were recruited and assigned in a stratified, alternating manner to receive a training tutorial (“trained”) or no intervention (“control”). Each conducted a baseline assessment of 24 clinical US images; where present, shadow width was measured using custom calipers. The trained group subsequently completed a standardized training module on shadow sizing. All subjects repeated measurements after ∼1 week. Group demographics were compared using Fisher's exact test. Measurements were compared to clinically reported stone sizes on corresponding CT and US using mixed-effects models. One millimeter concordance between shadow and CT size was compared using a generalized linear mixed-effects model. Results: Twenty-six subjects were included. There was no significant difference between groups in demographics, clinical role, or US experience. Mean reported CT and US stone sizes were 6.8 ± 4.0 mm and 10.3 ± 4.1 mm, respectively. At baseline, there was no difference in shadow size measurements between groups (p = 0.18), and shadow size was no more accurate than US stone size (p = 0.28 trained; p = 0.81 control), compared to CT. After training, overestimation bias of shadow size in the trained group decreased to 1.6 ± 0.5 mm (p

INTRODUCTION: A considerable publication record exists comparing sensitivity and specificity of radiological ultrasound (including point of care ultrasound) to computerized tomography for stone disease. However, the practical application of in-office ultrasound to support the growing number of kidney stone centers around the world represents a nuanced topic that is ripe for study and discussion. METHODS: We provide a descriptive analysis of how in-office ultrasound is being used as an adjunct to clinical care based on our experience during 50 days in clinic at an institutionally affiliated, multidisciplinary kidney stone center. Clinic subjects gave consent and underwent ultrasound as part of research studies. Ultrasonograms were shared with and verified by the treating physician before the patient was discharged from care. We counted the number of times research imaging altered the care plan. RESULTS: Of the 60 patients enrolled the clinician used the information obtained from the studies in 20 (33%) to determine the course of clinical care that resulted in a change in treatment or process. CONCLUSIONS: Ultrasound has the potential to be a cost-effective and valuable tool that can provide more efficient workflow within a kidney stone center or urology clinic.

INTRODUCTION AND OBJECTIVE:Emergency Department (ED) discharge practices are subject to inter-provider variation that can limit the implementation of evidence-based medicine. We convened a multi-di...

INTRODUCTION AND OBJECTIVE:Our goals were to validate stone comminution with an investigative clinical burst wave lithotripsy (BWL) system and to evaluate the use of ultrasonic propulsion to move t...

Purpose: Burst wave lithotripsy (BWL) is a new technology in development to fragment urinary stones. Ultrasonic propulsion (UP) is a separate technology under investigation for displacing stones. We measure the effect of propulsion pulses on stone fragmentation from BWL. Materials and Methods: Two artificial stone models (crystalline calcite, BegoStone plaster) and human calcium oxalate monohydrate (COM) stones measuring 5 to 8 mm were subjected to ultrasound exposures in a polyvinyl chloride tissue phantom within a water bath. Stones were exposed to BWL with and without propulsion pulses interleaved for set time intervals depending on stone type. Fragmentation was measured as a fraction of the initial stone mass fragmented to pieces smaller than 2 mm. Results: BegoStone model comminution improved from 6% to 35% (p

Nephrolithiasis is an increasingly common ailment in the United States. Ureteroscopic management has supplanted shockwave lithotripsy as the most common treatment of upper tract stone disease. Ureteral stricture is a rare but serious complication of stone disease and its management. The impact of new technologies and more widespread ureteroscopic management on stricture rates is unknown. We describe our experience in managing strictures incurred following ureteroscopy for upper tract stone disease.Records for patients managed at four tertiary care centers between December 2006 and October 2015 with the diagnosis of ureteral stricture following ureteroscopy for upper tract stone disease were retrospectively reviewed. Study outcomes included number and type (endoscopic, reconstructive, or nephrectomy) of procedures required to manage stricture.Thirty-eight patients with 40 ureteral strictures following URS for upper tract stone disease were identified. Thirty-five percent of patients had hydronephrosis or known stone impaction at the time of initial URS, and 20% of cases had known ureteral perforation at the time of initial URS. After stricture diagnosis, the mean number of procedures requiring sedation or general anesthesia performed for stricture management was 3.3 ± 1.8 (range 1-10). Eleven strictures (27.5%) were successfully managed with endoscopic techniques alone, 37.5% underwent reconstruction, 10% had a chronic stent/nephrostomy, and 10 (25%) required nephrectomy.The surgical morbidity of ureteral strictures incurred following ureteroscopy for stone disease can be severe, with a low success rate of endoscopic management and a high procedural burden that may lead to nephrectomy. Further studies that assess specific technical risk factors for ureteral stricture following URS are needed.

Maintenance of flexible ureteroscopes can involve high costs and administrative burden. Instrument fragility necessitates eventual repair, rendering scopes inaccessible during refurbishment. We conducted a multi-institutional prospective cohort study to identify perioperative factors influencing flexible ureteroscope durability. Patients undergoing flexible ureteroscopy (URS) at six United States endourology centers were enrolled between August 2014 and June 2015. Surgeon self-reported concern and satisfaction with scope performance as well as upward and downward angles of deflection for each scope tip were measured before and after each procedure. The need for scope repair was determined by the operating surgeon at the time of the procedure and recorded. 424 URS cases using 74 flexible ureteroscopes were identified. Scope repair was required in 28 cases (6.6%) involving 26 scopes (35.1%). Upon univariate analysis, shorter patient height, absence of guidewire use, presence of a ureteral access sheath (UAS), longer procedure time, larger stone size, lithotrite type, surgeon training level, and self-reported concern were associated with scope repair. Upon multivariate analysis, UAS use (OR = 2.53, p = 0.005) and degree loss of scope upward flexion during a case (OR = 1.02, p = 0.03) increased the odds of a scope needing repair while the use of safety guidewire decreased the odds of a scope repair (OR = 0.50, p = 0.045). Lithotrite use and surgeon concern were associated with degree loss of scope upward flexion. The use of a UAS, absence of a safety guidewire, and the loss of upward ureteroscope flexion should be considered when evaluating means of optimizing reusable ureteroscope durability.

Greater visual contrast between calculi and tissue would improve ultrasound (US) imaging of urolithiasis and potentially expand clinical use. The color Doppler twinkling artifact has been suggested to provide enhanced contrast of stones compared with brightness mode (B-mode) imaging, but results are variable. This work provides the first quantitative measure of stone contrast in humans for B-mode and color Doppler mode, forming the basis to improve US for the detection of stones.Using a research ultrasound system, B-mode imaging was tuned for detecting stones by applying a single transmit angle and reduced signal compression. Stone twinkling with color Doppler was tuned by using low-frequency transmit pulses, longer pulse durations, and a high-pulse repetition frequency. Data were captured from 32 subjects, with 297 B-mode and Doppler images analyzed from 21 subjects exhibiting twinkling signals. The signal to clutter ratio (i.e., stone to background tissue) (SCR) was used to compare the contrast of a stone on B-mode with color Doppler, and the contrast between stone twinkling and blood-flow signals within the kidney.The stone was the brightest object in only 54% of B-mode images and 100% of Doppler images containing stone twinkling. On average, stones were isoechoic with the tissue clutter on B-mode (SCR = 0 dB). Stone twinkling averaged 37 times greater contrast than B-mode (16 dB, p 0.0001) and 3.5 times greater contrast than blood-flow signals (5.5 dB, p = 0.088).This study provides the first quantitative measure of US stone to tissue contrast in humans. Stone twinkling contrast is significantly greater than the contrast of a stone on B-mode. There was also a trend of stone twinkling signals having greater contrast than blood-flow signals in the kidney. Dedicated optimization of B-mode and color Doppler stone imaging could improve US detection of stones.

Feasibility of ultrasonic propulsion and burst wave lithotripsy (BWL) to noninvasively reposition distal ureteral stones to facilitate passage and relieve pain was tested. Patients presenting to the clinic or emergency department were recruited. Thirteen subjects underwent ultrasonic propulsion (lower amplitude, longer duration pulses) alone, and 10 subjects also received intermittent BWL (higher amplitude, shorter duration pulses). All participants were awake and underwent a pain assessment pre- and post-procedure. For analysis, subjects were sub-categorized based on whether their stone was acute or chronic (present for ≤10 days or >10 days from their initial ED or symptomatic presentation, respectively). Seventeen subjects were enrolled in the acute study population and 6 subjects were enrolled in the chronic population. Overall, 94% of acute stones passed in an average of 3.4 days post-procedure relative to 54% in 7.5 days in the American Urological Association guidelines. 67% of chronic cases passed stones or fragments, and two surgeries were cancelled. Pain reduction was statistically significant ( p = 0.0215). Adverse events were limited to hematuria on initial urination post-procedure (BWL only, n = 3) and a mild sensation, akin to a pinprick, associated with fewer than 10 of 620 propulsion bursts ( n = 3). [Work supported by NIH-P01-DK04331.]

We report stone comminution in the first 18 human subjects by burst wave lithotripsy (BWL). Subjects undergoing clinical ureteroscopy (URS) for at least one stone ≤12 mm on computed tomography (CT) are recruited. During the planned URS, either before or after ureteroscope insertion, BWL is administered with a handheld probe for 10 min, and any stone fragmentation and tissue injury are observed. The primary effectiveness outcome is the volume percent comminution of the stone into fragments ≤2 mm, where fragment volume is determined by μCT of basketed fragments or image processing of the URS video using the laser fiber as a size reference. The primary safety outcome is independent, blinded grading of tissue injury from the URS video. Overall, 10 of 22 stones (45%) fragmented completely in 10 min. 64% and 73% were projected to fragment completely in 15 and 40 min, respectively. For reference, shock wave lithotripsy success is about 65% to fragments ≤4 mm in 40 min. Of the other six stones, one was larger than the beamwidth, two were smaller than the wavelength, and the ureteroscope introduced air bubbles around another. Only mild reddening with some hematuria was observed ureteroscopically. [Work supported by NIH-P01-DK04331.]

The goal is to test effectiveness and safety of transcutaneous ultrasound pulses for facilitating clearance of residual urinary stone fragments in a randomized control trial (RCT). The study is conducted in a clinic setting with the control and treatment arms undergoing all the same activities with the exception of the ultrasonic propulsion procedure and associated pain questionnaire. Subjects are followed 90 days for assessment of adverse events and for up to 5 years for stone growth and symptomatic stone visits. Twenty-six of 33 subjects have been recruited in each arm The most recent treatment is reported. The subject received shock wave lithotripsy and did not pass any fragments for 17 months. The subject was randomized to the treatment arm. Fragments began moving with the third 3-s propulsion pulse at output 2 of 5 levels. Fifty-two percent of propulsion pulses (41 of 79) resulted in fragment movement. The subject reported no pain at the beginning or end of the procedure and telephoned within 2 h to report passing 9 fragments, no hematuria, and no adverse events. The treatment results of this RCT are compelling as an immediate and casual effect was measured. [Work supported by NIH-P01-DK043881 and VA Puget Sound resources.]

Rationale & Objective Although maintaining high fluid intake is an effective low-risk intervention for the secondary prevention of urinary stone disease, many patients with stones do not increase their fluid intake. Study Design We describe the rationale and design of the Prevention of Urinary Stones With Hydration (PUSH) Study, a randomized trial of a multicomponent behavioral intervention program to increase and maintain high fluid intake. Participants are randomly assigned (1:1 ratio) to the intervention or control arm. The target sample size is 1,642 participants. Setting & Participants Adults and adolescents 12 years and older with a symptomatic stone history and low urine volume are eligible. Exclusion criteria include infectious or monogenic causes of urinary stone disease and comorbid conditions precluding increased fluid intake. Interventions All participants receive usual care and a smart water bottle with smartphone application. Participants in the intervention arm receive a fluid intake prescription and an adaptive program of behavioral interventions, including financial incentives, structured problem solving, and other automated adherence interventions. Control arm participants receive guideline-based fluid instructions. Outcomes The primary end point is recurrence of a symptomatic stone during 24 months of follow-up. Secondary end points include changes in radiographic stone burden, 24-hour urine output, and urinary symptoms. Limitations Periodic 24-hour urine volumes may not fully reflect daily behavior. Conclusions With its highly novel features, the PUSH Study will address an important health care problem. Funding National Institute of Diabetes and Digestive and Kidney Diseases. Trial Registration Registered at ClinicalTrials.gov with study number NCT03244189 .

Burst wave lithotripsy (BWL) is a transcutaneous technique with potential to safely and effectively fragment renal stones. Preclinical investigations of BWL require the assessment of potential renal injury. This study evaluates the capabilities of real-time ultrasound and MRI to detect and evaluate BWL injury that was induced in porcine kidneys.Ten kidneys from five female farm pigs were treated with either a 170 or 335 kHz BWL transducer using variable treatment parameters and monitored in real-time with ultrasound. Eight kidneys were perfusion fixed and scanned with a 3-Tesla MRI scanner (T1-weighted, T2-weighted, and susceptibility-weighted imaging), followed by processing via an established histomorphometric technique for injury quantification. In addition, two kidneys were separately evaluated for histologic characterization of injury quality.Observed B-mode hyperechoes on ultrasound consistent with cavitation predicted the presence of BWL-induced renal injury with a sensitivity and specificity of 100% in comparison to the histomorphometric technique. Similarly, MRI detected renal injury with a sensitivity of 90% and specificity of 100% and was able to identify the scale of lesion volumes. The injuries purposefully generated with BWL were histologically similar to those formed by shock wave lithotripsy.BWL-induced renal injury can be detected with a high degree of sensitivity and specificity by real-time ultrasound and post-treatment ex vivo MRI. No injury occurred in this study without cavitation detected on ultrasound. Such capabilities for injury detection and lesion volume quantification on MRI can be used for preclinical testing of BWL.

Objective To investigate whether the use of a belladonna and opium (B&O) rectal suppository administered immediately before ureteroscopy (URS) and stent placement could reduce stent-related discomfort. Methods A randomized, double-blinded, placebo-controlled study was performed from August 2013 to December 2014. Seventy-one subjects were enrolled and randomized to receive a B&O (15 mg/30 mg) or a placebo suppository after induction of general anesthesia immediately before URS and stent placement. Baseline urinary symptoms were assessed using the American Urological Association Symptom Score (AUASS). The Ureteral Stent Symptom Questionnaire and AUASS were completed on postoperative days (POD) 1, 3, and after stent removal. Analgesic use intraoperatively, in the recovery unit, and at home was recorded. Results Of the 71 subjects, 65 had treatment for ureteral (41%) and renal (61%) calculi, 4 for renal urothelial carcinoma, and 2 were excluded for no stent placed. By POD3, the B&O group reported a higher mean global quality of life (QOL) score ( P = .04), a better mean quality of work score ( P = .05), and less pain with urination ( P = .03). The B&O group reported an improved AUASS QOL when comparing POD1 with post-stent removal ( P = .04). There was no difference in analgesic use among groups ( P = .67). There were no episodes of urinary retention. Age was associated with unplanned emergency visits ( P P = .02) Conclusion B&O suppository administered preoperatively improved QOL measures and reduced urinary-related pain after URS with stent. Younger age was associated with severe stent pain and unplanned hospital visits.

Purpose: Kidney stone patients routinely have CT scans during diagnostic work-up before being referred to a tertiary center. How often these patients exceed the recommended dose limits for occupational radiation exposure of >100 mSv for 5 years and >50 mSv in a single year from CT alone remains unknown. This study aimed to quantify radiation doses from CTs received by stone patients before their evaluation at a tertiary care stone clinic. Methods: From November 2015 to March 2017, consecutive new patients enrolled into the Registry for Stones of the Kidney and Ureter (ReSKU™) had the dose-length product of every available CT abdomen/pelvis within 5 years of their initial visit recorded, allowing for an effective dose (EDose) calculation. Multivariate logistic regression analysis identified factors associated with exceeding recommended dose limits. Models were created to test radiation reducing effects of low-dose and phase-reduction CT protocols. Results: Of 343 noncontrast CTs performed, only 29 (8%) were low-dose CTs (calculated EDose 20 mSv and >50 mSv/year, respectively. Increased body mass index, number of scans, and multiphase scans were associated with exceeding exposure thresholds (p 50%. Conclusions: Stone patients referred to a tertiary stone center may receive excessive radiation from CT scans alone. Unnecessary phases and underutilization of low-dose CT protocols continue to take place. Enacting new approaches to CT protocols may spare stone patients from exceeding recommended dose limits.

Objective: The goal was to test whether stone composition and kidney phantom configuration affected comminution in extracorporeal shockwave lithotripsy (SWL) laboratory tests. Confinement may enhance the accumulation of dust and associated cavitation bubbles in the fluid surrounding the stone. It is known that high shockwave delivery rates in SWL are less effective because bubbles generated by one shockwave do not have sufficient time to dissolve, thereby shielding the next shockwave. Materials and Methods: Experiments were conducted with a lithotripter coupled to a water bath. The rate of comminution was measured by weighing fragments over 2 mm at 5-minute time points. First, plaster and crystal stones were broken in four phantoms: a nylon wire mesh, an open polyvinyl chloride (PVC) cup, a closed PVC cup, and an anatomical kidney model—the phantoms have decreasing fluid volumes around the stone. Second, the fluid volume in the kidney model was flushed with water at different rates (0, 7, and 86 mL/min) to remove dust. Results: The efficiency of breakage of stones decreases for the dust emitting plaster stones (percentage of breakage in 5 minutes decreased from 92% ± 2% [n = 3] in wire mesh to 19% ± 3% [n = 3] in model calix) with increasing confinement, but not for the calcite crystal stones that produced little dust (percentage of breakage changed from 87% ± 3% [n = 3] in wire mesh to 81% ± 3% [n = 3] in kidney model). Flushing the kidney phantom at the fastest rate improved comminution of smaller plaster stones by 27%. Conclusions: Phantoms restricting dispersion of dust were found to affect stone breakage in SWL and in vitro experiments should replicate kidney environments. The dust around the stone and potential cavitation may shield the stone from shockwaves and reduce efficacy of SWL. Understanding of stone composition and degree of hydronephrosis could be used to adapt patient-specific protocols.

INTRODUCTION AND OBJECTIVES:The American Urologic Association Guidelines recommends obtaining a 24-hour urine (24HU) in recurrent stone formers, patients high-risk for stone recurrence, and interested first-time stone formers. However, the advantage of selective therapy based on 24HU results over empiric treatment is unclear. We aimed to determine if obtaining a 24HU in high risk stone formers is associated with decreased recurrent stone episodes in a contemporary cohort exemplifying real-world clinical practice.METHODS:We used the MarketScan database to identify insured, employed subjects, 18 to 64 years old with a primary diagnosis of kidney and/or ureteral stones based on ICD-9 and ICD-10 diagnosis codes from 2008 to 2014. Subjects at high risk for infectious stones or with cystinuria were excluded. High risk stone formers (based on AUA guidelines), those undergoing stone surgery, and those with previous stone diagnoses one year prior to the date of inclusion were characterized with CPT and ICD codes, ...

Although reported success rates after pediatric pyeloplasty to correct ureteropelvic junction are high, failure may require intervention. We sought to characterize the incidence and timing of secondary procedures after pediatric pyeloplasty using a national employer based insurance database.Using the MarketScan® database we identified patients 0 to 18 years old who underwent pyeloplasty from 2007 to 2013 with greater than 3 months of postoperative enrollment. Secondary procedures following the index pyeloplasty were identified by CPT codes and classified as stent/drain, endoscopic, pyeloplasty, nephrectomy or transplant. The risk of undergoing a secondary procedure was ascertained using Cox proportional hazards models adjusting for demographic and clinical characteristics.We identified 1,976 patients with a mean ± SD followup of 23.9 ± 19.8 months. Overall 226 children (11.4%) had undergone at least 1 post-pyeloplasty procedure. The first procedure was done within 1 year in 87.2% of patients with a mean postoperative interval of 5.9 ± 11.1 months. Stents/drains, endoscopic procedures and pyeloplasties were noted in 116 (5.9%), 34 (1.7%) and 71 patients (3.1%), respectively. Length of stay was associated with undergoing a secondary procedure. Compared with 2 days or less the HR of 3 to 5 and 6 days or greater was 1.65 and 3.94 (p = 0.001 and0.001, respectively).Following pediatric pyeloplasty 1 of 9 patients undergoes at least 1 secondary procedure with the majority performed within the first year. One of 11 patients undergoes intervention more extensive than placement of a single stent or drain, requiring management strategies that generally signify recurrent or persistent obstruction. Estimates of pyeloplasty success in this national data set are lower than in other published series.

Ultrasonic propulsion is a new technology using focused ultrasound energy applied transcutaneously to reposition kidney stones. We report what are to our knowledge the findings from the first human investigational trial of ultrasonic propulsion toward the applications of expelling small stones and dislodging large obstructing stones.Subjects underwent ultrasonic propulsion while awake without sedation in clinic, or during ureteroscopy while anesthetized. Ultrasound and a pain questionnaire were completed before, during and after propulsion. The primary outcome was to reposition stones in the collecting system. Secondary outcomes included safety, controllable movement of stones and movement of stones less than 5 mm and 5 mm or greater. Adverse events were assessed weekly for 3 weeks.Kidney stones were repositioned in 14 of 15 subjects. Of the 43 targets 28 (65%) showed some level of movement while 13 (30%) were displaced greater than 3 mm to a new location. Discomfort during the procedure was rare, mild, brief and self-limited. Stones were moved in a controlled direction with more than 30 fragments passed by 4 of the 6 subjects who had previously undergone a lithotripsy procedure. The largest stone moved was 10 mm. One patient experienced pain relief during treatment of a large stone at the ureteropelvic junction. In 4 subjects a seemingly large stone was determined to be a cluster of small passable stones after they were moved.Ultrasonic propulsion was able to successfully reposition stones and facilitate the passage of fragments in humans. No adverse events were associated with the investigational procedure.

Purpose: Ultrasound is known to overestimate kidney stone size. We explored measuring the acoustic shadow behind kidney stones combined with different ultrasound imaging modalities to improve stone sizing accuracy.Materials and Methods: A total of 45 calcium oxalate monohydrate stones were imaged in vitro at 3 different depths with the 3 different ultrasound imaging modalities of conventional ray line, spatial compound and harmonic imaging. The width of the stone and the width of the acoustic shadow were measured by 4 operators blinded to the true size of the stone.Results: Average error between the measured and true stone width was 1.4 ± 0.8 mm, 1.7 ± 0.9 mm, 0.9 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Average error between the shadow width and true stone width was 0.2 ± 0.7 mm, 0.4 ± 0.7 mm and 0.0 ± 0.8 mm for ray line, spatial compound and harmonic imaging, respectively. Sizing error based on the stone width worsened with greater depth (p

To examine hospital-level variation in outcomes following benign urologic surgeries given that hospital-level variation in surgical outcomes can portend quality and appropriateness of care concerns and identify quality improvement opportunities in perioperative care.Using the Washington State Comprehensive Hospital Abstract Reporting System, we identified patients who underwent transurethral resection of the prostate (TURP), percutaneous nephrostolithotomy (PCNL), and pyeloplasty from 2003 to 2008. We classified prolonged postoperative length of stay (LOS) as that exceeding the 75th percentile, and we measured the rate of Agency for Healthcare Quality Patient Safety Indicators, readmissions, and death. We calculated hospital-specific observed-to-expected event rates using random effects multilevel multivariable models adjusted for age and comorbidity.We identified 6699 TURP patients at 54 hospitals, 2541 PCNL patients at 45 hospitals, and 584 pyeloplasty patients at 36 hospitals. Complication rates were highest after PCNL (22.9% prolonged LOS vs 17.3% for TURP and 13.9% for pyeloplasty, P .001; 3.4% 90-day mortality vs 0.6% for TURP and 0% for pyeloplasty). Hospital-level variation was most substantial for LOS after TURP and pyeloplasty (8.1% and 14.3% of variance in prolonged LOS, respectively).Hospital-level variation is common after benign inpatient urologic surgeries and may relate to difference in perioperative provider practice patterns. The morbidity of PCNL in this study was higher than expected and merits further investigation.