Project description:PurposeOur 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 methodsAdult 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.ResultsTwenty-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.ConclusionsThis 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.
Project description:Marine mammals may develop kidney stones, which can be challenging to treat. We describe burst wave lithotripsy (BWL) and ultrasonic propulsion to treat ureteral calculi in a 48-year-old female bottlenose dolphin (Tursiops truncatus) and to reduce renal stone burden in a 23-year-old male harbor seal (Phoca vitulina). BWL and ultrasonic propulsion were delivered transcutaneously in sinusoidal ultrasound bursts to fragment and reposition stones. Targeting and monitoring were performed with real-time imaging integrated within the BWL system. Four dolphin stones were obtained and fragmented ex vivo. The dolphin case received a 10-min and a 20-min BWL treatment conducted approximately 24 h apart to treat two 8-10 mm partially obstructing right mid-ureteral stones, using oral sedation alone. For the harbor seal, while under general anesthesia, retrograde ureteroscopy attempts were unsuccessful because of ureteral tortuosity, and a 30-min BWL treatment was targeted on one 10-mm right kidney stone cluster. All 4 stones fragmented completely to < 2-mm fragments in < 20 min ex vivo. In the dolphin case, the ureteral stones appeared to fragment, spread apart, and move with ultrasonic propulsion. On post-treatment day 1, the ureteral calculi fragments shifted caudally reaching the ureteral orifice on day 9. On day 10, the calculi fragments passed, and the hydroureter resolved. In the harbor seal, the stone cluster was observed to fragment and was not visible on the post-operative computed tomography scan. The seal had gross hematuria and a day of behavior indicating stone passage but overall, an uneventful recovery. BWL and ultrasonic propulsion successfully relieved ureteral stone obstruction in a geriatric dolphin and reduced renal stone burden in a geriatric harbor seal.
Project description:PurposeWe report stone comminution in the first 19 human subjects by burst wave lithotripsy (BWL), which is the transcutaneous application of focused, cyclic ultrasound pulses.Materials and methodsThis was a prospective multi-institutional feasibility study recruiting subjects undergoing clinical ureteroscopy (URS) for at least 1 stone ≤12 mm as measured on computerized tomography. During the planned URS, either before or after ureteroscope insertion, BWL was administered with a handheld transducer, and any stone fragmentation and tissue injury were observed. Up to 3 stones per subject were targeted, each for a maximum of 10 minutes. The primary effectiveness outcome was the volume percent comminution of the stone into fragments ≤2 mm. The primary safety outcome was the independent, blinded visual scoring of tissue injury from the URS video.ResultsOverall, median stone comminution was 90% (IQR 20, 100) of stone volume with 21 of 23 (91%) stones fragmented. Complete fragmentation (all fragments ≤2 mm) within 10 minutes of BWL occurred in 9 of 23 stones (39%). Of the 6 least comminuted stones, likely causative factors for decreased effectiveness included stones that were larger than the BWL beamwidth, smaller than the BWL wavelength or the introduction of air bubbles from the ureteroscope. Mild reddening of the papilla and hematuria emanating from the papilla were observed ureteroscopically.ConclusionsThe first study of BWL in human subjects resulted in a median of 90% comminution of the total stone volume into fragments ≤2 mm within 10 minutes of BWL exposure with only mild tissue injury.
Project description:BackgroundWe evaluated the treatment outcomes of ureteral stones according to energy intensity generated by extracorporeal shock wave lithotripsy (ESWL).MethodsWe retrospectively analyzed 150 patients who underwent ESWL for treatment of ureteral stones between September 2018 and February 2020. All stones were confirmed by a computed tomography examination, and the size, location, skin-to-stone distance, and Hounsfield units (HU) of the stones were assessed. In addition, patient characteristics including body mass index and estimated glomerular filtration rate, which can affect treatment outcome, were also evaluated. The success or failure of ESWL was confirmed according to the session, and the factors affecting the treatment outcome were analyzed using a logistic regression model.ResultsOf the 150 patients, 82 (54.7%) had stones in the proximal ureter, 5 (3.3%) in the mid, and 63 (42.0%) in the distal ureter. Patients underwent ESWL an average of 1.5 times, and the success rate according to session was 65.3% for the first, 83.3% for the second, and 90.0% for the third session. A multivariate analysis revealed that stone size [odds ratio (OR) 0.81, 95% confidence interval (CI), 0.66-0.99, P=0.049] and HU (OR 0.99, 95% CI, 0.98-0.99, P=0.001) were significant factors affecting the success rate after the first ESWL session; ESWL intensity was not related to success rate. Stone size (OR 0.78, 95% CI, 0.62-0.96, P=0.022) was the only significant factor affecting the success rate in the third session.ConclusionsStone size and HU affected the ESWL success rate. ESWL intensity was not significantly related to the success rate, so it should be adjusted according to patient pain and the degree of stone fragmentation.
Project description:Early shock wave lithotripsy is associated with higher stone-free rate compared to delayed treatment of ureteral stones, but may constitute overtreatment because ureteral stones can pass spontaneously. We studied the association between time to treatment and stone-free rate in patients with ureteral stones to determine optimal shock wave lithotripsy timing. We retrospectively analyzed 537 patients undergoing shock wave lithotripsy for ureteral stones. Patients were divided into five groups according to time from onset of symptoms to lithotripsy-urgent (0-3 days), early (4-30 days), late (31-60 days), long-delayed lithotripsy (≥ 61 days), and asymptomatic. Stone-free rates were compared among groups. Mean age and stone size were 55.6 ± 13.1 years and 7.48 ± 3.29 mm, respectively. Mean number of shock wave lithotripsy sessions and stone-free rate were 1.37 and 91.6%, respectively, in the overall population. Stone-free rates were 95.2%, 96.8%, 91.3%, 86.3%, and 82.7% in urgent, early, late, long-delayed lithotripsy, and asymptomatic groups, respectively. Long-delayed lithotripsy and asymptomatic groups had significantly more lithotripsy sessions and lower stone-free rate, compared to urgent and early lithotripsy groups. In multivariate analysis, time to lithotripsy [long-delayed lithotripsy (odds ratio: 0.273, p = 0.004) and asymptomatic nature (odds ratio: 0.236, p = 0.002)] and age (odds ratio: 0.959, p = 0.003) independently affected stone-free rate. In conclusion, time to lithotripsy is a strong predictive factor for stone-free status following shock wave lithotripsy. Urgent shock wave lithotripsy did not improve stone-free rate if performed within 1 month. However, time to shock wave lithotripsy > 2 months reduced likelihood of stone-free status.
Project description:ObjectiveTo compare the clinical efficiency and safety of emergency extracorporeal shock wave lithotripsy (eESWL) and delayed extracorporeal shock wave lithotripsy (dESWL) in the treatment of ureteral stones.MethodsCochrane Library, PubMed, Google Scholar, and Web of Science were searched from January 1, 1992 to September 30, 2022, and all comparative studies involving eESWL and dESWL for ureteral calculi were included. Statistical analysis was performed using Review Manager 5.3 software. Funnel plot was used to evaluated publication bias.ResultsA total of 9 articles involving 976 patients diagnosed with ureteral stones were included. The results showed that the stone-free rate (SFR) after four weeks was significantly higher in the eESWL group than in the dESWL group [relative risk (RR) = 1.22, 95% confidence interval (CI): 1.13-1.32, P < 0.01]. In subgroup analysis of different stone locations, proximal ureteral calculi [RR = 1.25, 95% CI: 1.14-1.38, P < 0.01] and mid-to-distal ureteral calculi [RR = 1.18, 95% CI: 1.03-1.34, P < 0.05] all showed a higher SFR in the eESWL group. eESWL significantly shortened the stone-free time(SFT) [mean difference (MD) = -5.75, 95% CI: -9.33 to -2.17, P < 0.01]. In addition, eESWL significantly reduced auxiliary procedures [RR = 0.53, 95% CI: 0.40-0.70, P < 0.01]. No significant difference in complications was found between the two groups [RR = 0.90, 95% CI: 0.69-1.16, P > 0.05].ConclusioneESWL can significantly improve SFR, shorten SFT, and reduce auxiliary procedures.
Project description:PurposeTo compare the effectiveness, safety, and cost between ultrasound-guided shock wave lithotripsy (SWL) with an early second session protocol and ureteroscopy (URS) in patients with proximal ureteral stones using the propensity score matching (PSM) method based on a large prospective study.MethodsThis prospective study was conducted in a tertiary hospital from June 2020 to April 2022. Patients who underwent lithotripsy (SWL or URS) for proximal ureteral stones were enrolled. The stone-free rate (SFR), complications, and cost were recorded. PSM analysis was performed.ResultsA total of 1230 patients were included, of whom 81.1% (998) were treated with SWL and 18.9% (232) were treated with URS. After PSM, the SWL group had an equivalent SFR at one month (88.7 vs. 83.6%, P = 0.114) compared with the URS group. Complications were rare and comparable between the two groups, while the incidence of ureteral injuries was higher in the URS group compared with the SWL group (1.4 vs. 0%, P = 0.011). The hospital stay was significantly shorter (1 day vs. 2 days, P < 0.001), and the cost was considerably less (2000 vs. 25,053, P < 0.001) in the SWL group compared with the URS group.ConclusionThis prospective PSM cohort demonstrated that ultrasound-guided SWL with an early second session protocol had equivalent effectiveness but better safety and lower cost compared with URS in the treatment of patients with proximal ureteral stones, whether the stones were radiopaque or radiolucent. These results will facilitate treatment decisions for proximal ureteral stones.
Project description: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.
Project description:BackgroundAlthough some trials assessed the efficacy and safety of the α-blocker in facilitating renal and ureteral stones expulsion after extracorporeal shock wave lithotripsy (ESWL), the role of the α-blocker in facilitating upper urinary calculi expulsion after ESWL remain controversial.AimsTo determine the efficacy and safety of the α-blocker in facilitating renal and ureteral stones expulsion after ESWL.MethodsA literature search was carried out using the PubMed database, EMBASE and the Cochrane Library database to identify relevant studies. Two reviewers independently extracted data and assessed methodological quality. Pooled effect estimates were obtained using a fixed- and random-effects meta-analysis.ResultsThe meta-analysis included 23 RCTs, α-blocker significantly enhanced expulsion rate of upper urinary tract calculi after ESWL (P<0.00001; RR 1.21; 95% CI 1.12-1.31), significantly promoted steinstrasse expulsion (P=0.03; RR 1.25; 95% CI 1.03-1.53), significantly shortened the discharge time of upper urinary tract calculi (P=0.0001; MD -2.12; 95% CI -3.20--1.04), significantly reduced the patient's pain VAS score (P=0.001; RR -1.0; 95% CI -1.61--0.39). Compared with the control group, dizziness (P=0.002; RR 5.48; 95% CI 1.91-15.77), anejaculation (P=0.02; RR 12.17; 95% CI 1.61-91.99) and headache (P=0.04; RR 4.03; 95% CI 1.04-15.72) in the α-blocker group was associated with a higher incidence.ConclusionsTreatment with α-blocker after ESWL appears to be effective in enhancing expulsion rate of upper urinary tract calculi, shortening the discharge time of upper urinary tract calculi, reducing the patient's pain. The side effects of α-blocker were light and few.
Project description:Burst wave lithotripsy (BWL) is a technology under clinical investigation for non-invasive fragmentation of urinary stones. Under certain ranges of ultrasound exposure parameters, this technology can cause cavitation in tissue leading to renal injury. This study sought to measure the focal pressure amplitude needed to cause cavitation in vivo and determine its consistency in native tissue, in an implanted stone model and under different exposure parameters. The kidneys of eight pigs were exposed to transcutaneous BWL ultrasound pulses. In each kidney, two locations were targeted: the renal sinus and the kidney parenchyma. Each was exposed for 5 min at a set pressure level and parameters, and cavitation was detected using an active cavitation imaging method based on power Doppler ultrasound. The threshold was determined by incrementing the pressure amplitude up or down after each 5-min interval until cavitation occurred/subsided. The pressure thresholds were remeasured postsurgery, targeting an implanted stone or collecting space (in sham). The presence of a stone or sham surgery did not significantly impact the threshold for tissue cavitation. Targeting parenchyma instead of kidney collecting space and lowering the ultrasound pulse repetition frequency both resulted in an increased pressure threshold for cavitation.