The optimal stent pusher position to achieve successful ureteral stent insertion under fluoroscopic guidance.

Objective: To examine factors to predict the optimal stent pusher position when inserting ureteral stents under fluoroscopy. Methods: We retrospectively reviewed 327 patients who underwent ureteral stent insertion. We considered the pubic bone as a useful anatomical landmark to insert ureteral stents under fluoroscopic guidance. Thus, we categorized patients into three groups (proximal, middle, and distal groups) according to the position of the radiopaque tip of the push catheter when inserting the ureteral stent. Success was defined as a completely curled ureteral stent tail. We compared stent insertion success rates among the three groups. A multivariate analysis was performed to identify the factors affecting stent insertion success. Results: In men, 36 (63.2%) cases were deemed successful in the proximal group compared with 40 (80.0%) cases in the middle group and 12 (20.7%) cases in the distal group (p<0.001). In women, 26 (45.6%) cases were deemed successful in the proximal group compared with 54 (98.2%) cases in the middle group and 38 (76.0%) cases in the distal group (p<0.001). With the multivariate analysis, the stent pusher position was the most significant factor influencing successful stent insertion (men: odds ratio 6.00, 95% confidence interval 2.66-13.51, p<0.001; women: odds ratio 37.80, 95% confidence interval 4.94-289.22, p<0.001). Conclusion: The position of the stent pusher affects stent insertion success. The middle of the pubic symphysis is the optimal position for the radiopaque tip of the pusher when inserting ureteral stents under fluoroscopic guidance.

Re-salvage focal low-dose rate brachytherapy for local recurrence of prostate cancer after salvage focal low-dose rate brachytherapy.

Introduction: Salvage brachytherapy represents an effective treatment for local recurrence of prostate cancer after prior external beam radiotherapy. However, the optimal therapeutic strategies for local recurrence after salvage brachytherapy have not yet been determined. Case presentation: We describe the case of a 77-year-old man who underwent re-salvage focal low-dose rate brachytherapy for local recurrence after carbon ion radiotherapy and salvage focal low-dose rate brachytherapy. We performed re-salvage focal low-dose rate brachytherapy for the recurrence with a different type of seed, which resulted in a significant reduction in the prostate-specific antigen level. During the 35-month follow-up after re-salvage focal low-dose rate brachytherapy, no recurrence of prostate cancer and no severe radiation-related toxicities were observed. Conclusion: Our patient was successfully treated with re-salvage focal low-dose rate brachytherapy for local recurrence after salvage focal low-dose rate brachytherapy. This treatment strategy might be effective for such patients and is not associated with sexual dysfunction or severe adverse events.

Evaluation of ureteral injuries caused by ureteral access sheath insertion during ureteroscopic lithotripsy.

OBJECTIVE: To evaluate ureteral injuries caused by insertion of a 13-Fr ureteral access sheath and identify factors (other than pre-stenting) that are predictive of ureteral injury. METHODS: We enrolled 201 patients who underwent ureteroscopic lithotripsy (URSL). We excluded 80 patients who underwent ureteral stent insertion before URSL, 10 patients who did not use a ureteral access sheath, and 2 patients in whom a ureteral access sheath could not be inserted. In total, 109 patients were analyzed; all underwent insertion of a 13-Fr ureteral access sheath. We investigated ureteral injuries using the Traxer ureteral injury scale. RESULTS: There were 21 (19.3%) cases of ureteral access sheath-related ureteral injury, including 11 (10.1%) grade 2 cases and 10 (9.2%) grade 3 cases. The ureteral injury location was the proximal ureter in 20 cases (18.3%), middle ureter in one case (0.9%), and distal ureter in zero cases. Multiple logistic regression analysis showed that male sex and smaller stone diameter were significant predictive factors for ureteral injury (p = 0.037, odds ratio [OR]: 5.19, 95% confidence interval [CI]: 1.11-24.3 and p = 0.02, OR: 0.83, 95% CI: 0.71-0.97, respectively). Postoperative ureteral stricture did not occur in any cases. CONCLUSIONS: The rate of ureteral injury caused by a 13-Fr ureteral access sheath was considerable, and most ureteral injuries occurred in the proximal ureter. Male sex and smaller stone diameter were significant predictive factors for ureteral injury. The proximal ureter should be confirmed when using a 13-Fr ureteral access sheath, particularly in male patients and patients with small stones.

Comparison of Empower and M-arm for One-surgeon Basketing in Ureteroscopic Lithotripsy: A Simulator Study by Non-doctors.

OBJECTIVE: To compare the Empower and M-arm for stone retrieval during ureteroscopic lithotripsy in a simulator. METHODS: We used flexible ureteroscopy to compare use of the Empower and use of the M-arm, both of which are one-surgeon basketing techniques. LithoVue and ZeroTip stone extraction devices were used. All participants were nurses who had never handled a ureteroscope. They retrieved 3 stones in the simulator using the Empower or M-arm. We compared the stone retrieval time, number of times the retrieval device was opened and closed, number of times the line of sight was removed from the endoscope monitor, number of times the participant lost sight of a stone, and participants' subjective evaluations. RESULTS: The stone retrieval time was significantly shorter with the Empower than M-arm (10.0 vs. 19.9 min, respectively; P = .02). The mean number of times the retrieval device was opened and closed and the mean number of times the line of sight was removed from the endoscope monitor were significantly lower with the Empower (24 vs. 53 times, P = .01 and 3.1 vs. 51.5 times, P < .001, respectively). The mean number of times the participant lost sight of a stone tended to be lower with the Empower (9.4 vs. 25.3, P = .06). All participants indicated that the Empower is better for stone retrieval by beginners. CONCLUSION: The Empower reduces the stone retrieval time compared with the M-arm. We consider that the Empower has the potential to be useful in ureteroscopic lithotripsy.

Prospective randomized controlled trial comparing a ureteral stent crossing versus not crossing the bladder midline.

PURPOSE: To evaluate the correlation between the position of a ureteral stent and stent-related symptoms in a single-center randomized study. METHODS: A total of 113 patients who required ureteral stent placement after lithotripsy were randomized at a 1:1 ratio into groups with stents crossing and not crossing the bladder midline. The ureteral stent remained in place until postoperative day 14, when we obtained each patient's International Prostate Symptom Score (IPSS), overactive bladder symptom score (OABSS), and visual analog scale (VAS) pain score. RESULTS: Comparing changes from baseline IPSS and OABSS scores between the two groups, the midline crossing group had a worse OABSS total score than the not crossing group (3.0 ± 2.8 vs. 2.0 ± 3.3; p = 0.032). There was no significant difference between the crossing and not crossing groups in IPSS total score (6.8 ± 7.6 vs. 5.1 ± 8.5; p = 0.14). The OABSS urgency mean score was significantly lower in the not crossing than in the crossing group (1.1 ± 1.8 vs. 1.6 ± 1.8; p = 0.042). However, there was no significant difference between groups for remaining items of the IPSS and OABSS and the mean VAS total pain score (1.9 ± 2.7 vs. 1.2 ± 1.9; p = 0.14). CONCLUSION: A ureteral stent that crossed the bladder midline led to worse urinary symptoms. Choosing the appropriate stent length for each patient is important to minimize stent-related symptoms. TRIAL REGISTRATION DATE: 1 October 2018; number: UMIN000034067.

Effectiveness and Safety of Ureteroscopic Lithotripsy in Young, Old-Old, and Oldest Old Patients.

Objectives: To investigate the efficacy and safety of ureteroscopic lithotripsy (URSL) in young, old-old, and oldest old patients. Materials and Methods: We enrolled 157 patients who underwent URSL. We divided the patients into young (<65 years), old-old (65-84 years), and oldest old (≥85 years) groups and compared the safety of surgery between young vs old-old and young vs oldest old, separately. Results: In the <65 group, 65 to 85 group, and ≥85 group, respectively, the mean stone diameters were 8.9 ± 4.9, 10.8 ± 7.7, and 11.4 ± 6.3 mm; mean operative time was 76.6 ± 33.1, 86.7 ± 44.7, and 84.0 ± 44.5 min; the stone-free rates were 95.9%, 94.4%, and 96.3%; and the complication rates were 8.2%, 9.8%, and 3.7%. Conclusions: In this study, we showed the feasibility and safety of URSL for elderly people. Although oldest old (≥85 years) people had multiple comorbidities with low performance status, URSL could be performed with acceptable complication rates. Clinical Trial Registration Number: 1809-1.

The nightside cloud-top circulation of the atmosphere of Venus.

Although Venus is a terrestrial planet similar to Earth, its atmospheric circulation is much different and poorly characterized1. Winds at the cloud top have been measured predominantly on the dayside. Prominent poleward drifts have been observed with dayside cloud tracking and interpreted to be caused by thermal tides and a Hadley circulation2-4; however, the lack of nightside measurements over broad latitudes has prevented the unambiguous characterization of these components. Here we obtain cloud-tracked winds at all local times using thermal infrared images taken by the Venus orbiter Akatsuki, which is sensitive to an altitude of about 65 kilometres5. Prominent equatorward flows are found on the nightside, resulting in null meridional velocities when these are zonally averaged. The velocity structure of the thermal tides was determined without the influence of the Hadley circulation. The semidiurnal tide was found to have an amplitude large enough to contribute to the maintenance of the atmospheric superrotation. The weakness of the mean meridional flow at the cloud top implies that the poleward branch of the Hadley circulation exists above the cloud top and that the equatorward branch exists in the clouds. Our results should shed light on atmospheric superrotation in other celestial bodies.

[EFFECTIVENESS AND SAFETY OF TRANSURETHRAL ENUCLEATION WITH BIPOLAR (TUEB) IN THE ELDERLY (OVER 80 YEARS OLD)].

(Objective) The number of elderly people is increasing in Japan, and there are many reports on the safety and effectiveness of treatment for the elderly. As the number of elderly men with benign prostatic hyperplasia is increasing, it is necessary to consider surgical treatment for the elderly. We analyzed the treatment outcome of transurethral enucleation with bipolar (TUEB), and investigated the effectiveness and safety of TUEB in the elderly (over 80 years old) at Saiseikai Izuo Hospital. (Methods) In total, 47 patients who underwent TUEB were enrolled. The patients were divided into two groups by age (< 80 years old group and ≥ 80 years old group). We investigated the factors related to the occurrence of complications by multivariate analysis. (Results) Mean duration of surgery was 107.8 min and 85.8 min (p=0.11) in the < 80 group and the ≥ 80 group, respectively. Mean resected prostate weight was 33.9 g and 31.0 g (p=0.61) and mean hemoglobin loss was 1.29 g/dL and 0.66 g/dL (p=0.01), respectively. Hemoglobin loss was significantly lower in the over 80 years old group. Complications were observed in six patients (24.0%) in the under 80 years old group and two patients (9.1%) in the over 80 years old group; however, there was no significant difference between the two groups (p=0.17). Fever was a complication in the over 80 years old group. In multivariate analysis, operative time was significant predictive factor for complications (odds ratio: 1.03, 95% confidence interval: 1.00-1.06, p=0.03) and, age was not significant predictive factor. (Conclusion) This study shows that TUEB for patients over 80 years old is effective and safe.

Complete intraureteral stent placement relieves daytime urinary frequency compared with conventional placement in patients with an indwelling ureteral stent: post-hoc analysis of a randomized, controlled trial.

A previous randomized, controlled trial had demonstrated that complete intraureteral stent placement (CIU-SP) was superior to conventional stent placement (C-SP) in terms of improvement of stent-related urinary symptoms. However, it is unclear as to which subdomain symptom and cohort could benefit the most from CIU-SP compared to C-SP in urinary symptoms while considering the baseline urinary status. To determine this, a post-hoc analysis was performed using data from a previous study (CIU-SP group, n = 39; C-SP group, n = 41). We assessed the mean changes in the International Prostate Symptom Score (I-PSS) and the Overactive Bladder Symptom Score (OABSS) from baseline to day 14. Statistical comparison between the two groups was performed using analysis of covariance with adjustment of baseline urinary status as a covariate. Among 80 patients, the total I-PSS was significantly lower in the CIU-SP group than in the C-SP group in the cohort with mild urinary symptoms (P = 0.005), but not in those with moderate/severe symptoms (P = 0.521). The CIU-SP group showed significantly improved I-PSS and OABSS daytime frequencies, with the highest t statistic (2.47 and 2.10, respectively) among subdomains of both symptom scores compared with the C-SP group (both P < 0.001). In multivariate regression analysis, the stent placement method (CIU-SP vs. C-SP) was independently associated with the I-PSS daytime frequency on day 14 (P = 0.017). This study suggests that CIU-SP significantly improved stent-related daytime frequency compared with C-SP, and it may benefit especially those patients who have mild urinary symptoms before the placement of ureteral stents.

How waves and turbulence maintain the super-rotation of Venus' atmosphere.

Venus has a thick atmosphere that rotates 60 times as fast as the surface, a phenomenon known as super-rotation. We use data obtained from the orbiting Akatsuki spacecraft to investigate how the super-rotation is maintained in the cloud layer, where the rotation speed is highest. A thermally induced latitudinal-vertical circulation acts to homogenize the distribution of the angular momentum around the rotational axis. Maintaining the super-rotation requires this to be counteracted by atmospheric waves and turbulence. Among those effects, thermal tides transport the angular momentum, which maintains the rotation peak, near the cloud top at low latitudes. Other planetary-scale waves and large-scale turbulence act in the opposite direction. We suggest that hydrodynamic instabilities adjust the angular-momentum distribution at mid-latitudes.

Highly porous nature of a primitive asteroid revealed by thermal imaging.

Carbonaceous (C-type) asteroids1 are relics of the early Solar System that have preserved primitive materials since their formation approximately 4.6 billion years ago. They are probably analogues of carbonaceous chondrites2,3 and are essential for understanding planetary formation processes. However, their physical properties remain poorly known because carbonaceous chondrite meteoroids tend not to survive entry to Earth's atmosphere. Here we report on global one-rotation thermographic images of the C-type asteroid 162173 Ryugu, taken by the thermal infrared imager (TIR)4 onboard the spacecraft Hayabusa25, indicating that the asteroid's boulders and their surroundings have similar temperatures, with a derived thermal inertia of about 300 J m-2 s-0.5 K-1 (300 tiu). Contrary to predictions that the surface consists of regolith and dense boulders, this low thermal inertia suggests that the boulders are more porous than typical carbonaceous chondrites6 and that their surroundings are covered with porous fragments more than 10 centimetres in diameter. Close-up thermal images confirm the presence of such porous fragments and the flat diurnal temperature profiles suggest a strong surface roughness effect7,8. We also observed in the close-up thermal images boulders that are colder during the day, with thermal inertia exceeding 600 tiu, corresponding to dense boulders similar to typical carbonaceous chondrites6. These results constrain the formation history of Ryugu: the asteroid must be a rubble pile formed from impact fragments of a parent body with microporosity9 of approximately 30 to 50 per cent that experienced a low degree of consolidation. The dense boulders might have originated from the consolidated innermost region or they may have an exogenic origin. This high-porosity asteroid may link cosmic fluffy dust to dense celestial bodies10.

Effect of ureteral stent diameter on ureteral stent-related symptoms.

OBJECTIVE: This study investigated the correlation between ureteral stent diameter and stent-related symptoms. METHODS: This study evaluated 17 patients (53 [74.6%] men, 18 [25.4%] women; mean [±SD] age 59.3 ± 14.2 years) who underwent ureteral stent placement before ureteroscopic lithotripsy (URSL) and in whom the ureteral stent tail was positioned inside the bladder without crossing the midline. All stents were Inlay Optima stents. Stent diameter (6 or 4.7 Fr) and length (24 or 26 cm) were chosen at the surgeon's discretion. Patients were classified into two groups (Group 1, 6-Fr stent; Group 2, 4.7-Fr stent). Urinary symptoms before insertion of the ureteral stents and the day before URSL were assessed using the International Prostate Symptom Score (IPSS) and Overactive Bladder Symptom Score (OABSS). In addition, patient background and changes in the IPSS and OABSS were compared. Factors affecting ureteral stent-related symptoms were evaluated using multivariate analysis. RESULTS: Compared with Group 2, Group 1 had a worse total IPSS (P = 0.02), as well as intermittency (P = 0.009), urgency (P = 0.008), voiding symptoms (Q1 + Q3 + Q5 + Q6; P = 0.046), and storage symptoms (Q2 + Q4 + Q7; P = 0.017) subscores on the IPSS, total OABSS (P = 0.045) and OABSS urgency subscore (P = 0.002). Multivariate analysis revealed that stent diameter was significantly associated with total IPSS (P = 0.007) and OABSS (P = 0.036). CONCLUSION: This is the first study to show that larger-diameter ureteral stents induce significantly worse urinary symptoms. Ureteral stents with smaller diameters are recommended to improve ureteral stent-related symptoms.

Efficacy and Safety of Complete Intraureteral Stent Placement versus Conventional Stent Placement in Relieving Ureteral Stent Related Symptoms: A Randomized, Prospective, Single Blind, Multicenter Clinical Trial.

PURPOSE: We compared the efficacy and safety of complete and conventional stent placement to relieve ureteral stent related symptoms. MATERIALS AND METHODS: We randomized 85 patients who required ureteral stent placement after lithotripsy into an intraureteral or a conventional stent placement group. The ureteral stent remained in place until postoperative day 14. We evaluated scores on the visual analog scale pain, the SF-36 (36-Item Short-Form Health Survey), the I-PSS (International Prostate Symptom Score) and the OABSS (Overactive Bladder Symptom Score) on postoperative days 3 and 14. We also assessed the total amount of analgesics administered and stent related complications. RESULTS: Overall the records of 80 patients were analyzed. Pain scores were significantly lower in the intraureteral vs the conventional stent placement group (postoperative days 3 and 14, 4.85 vs 9.78, p = 0.003, and 3.15 vs 6.20, p = 0.014, respectively). The total I-PSS score (postoperative days 3 and 14, 10.41 vs 14.90, p = 0.006, and 11.67 vs 16.10, p = 0.022, respectively) and total analgesic use (19.23 vs 88.54 mg, p <0.001) were significantly lower in the intraureteral group. However, differences in the SF-36 and the total OABSS scores did not significantly differ. On subgroup analysis the pain score in the groin and bladder areas, incomplete emptying and daytime frequency on the I-PSS, the quality of life index and daytime frequency on the OABSS were significantly better in the intraureteral stent placement group than the conventional stent placement group on postoperative days 3 and 14 (all p <0.05). There was no difference in the complication rate between the 2 groups. CONCLUSIONS: Intraureteral stent placement may be associated with less ureteral stent related discomfort than conventional stent placement. This novel placement method is feasible and safe, and it can be immediately used in daily clinical practice.

Ureteral wall thickness as a significant factor in predicting spontaneous passage of ureteral stones of ≤ 10 mm: a preliminary report.

PURPOSE: To evaluate the clinical significance of ureteral wall thickness (UWT) for predicting spontaneous passage (SP) of uncomplicated ureteral stones of ≤ 10 mm. METHODS: We retrospectively reviewed 418 patients with a diagnosis of uncomplicated ureteral stones who presented to Kori Hospital from 2011 to 2018. The maximum stone diameter and UWT at the stone site were measured from axial computed tomography images. Clinical predictors of 4-week SP were assessed using univariate and multivariate analyses. Receiver operating characteristic (ROC) curve analysis was applied to evaluate the accuracy of factors in predicting SP of ureteral stones. RESULTS: Of the 418 patients, 202 (48.3%) spontaneously passed their stones within 4 weeks of their initial visit. Multivariate analysis showed that stone location, stone size, and UWT (odds ratio, 0.40; P < 0.001) were independent predictors of 4-week SP. ROC analysis showed that 2.71 mm was the optimal cut-off value for UWT, with a predictive accuracy of 0.83. Low UWT had a significantly higher 4-week SP rate than high UWT (76.4% vs. 14.7%, respectively; P < 0.001). In addition, high UWT was associated with a higher risk of stone-related complications within 4 weeks compared with low UWT (16.4% vs. 7.2%, respectively; P = 0.0044). CONCLUSIONS: UWT can serve as a potential predictive factor for 4-week SP and may help physicians to select patients who require immediate interventions among those with ≤ 10-mm ureteral stones.

Chronological changes in epidemiological characteristics of lower urinary tract urolithiasis in Japan.

OBJECTIVES: To determine changes and trends in the annual incidence and epidemiological aspects of lower urinary tract stones in Japan. METHODS: Data about patients who had been diagnosed by urologists in 2015 with first and recurrent lower urinary tract stones were collected from 301 hospitals approved by the Japanese Board of Urology. The estimated annual incidence according to sex, age and stone composition was compared with previous nationwide surveys between 1965 and 2005. RESULTS: The incidence of lower urinary tract stones in Japan has steadily increased from 4.7 per 100 000 in 1965 to 12.0 per 100 000 in 2015. However, the age standardized annual incidence of lower urinary tract stones has remained relatively stable over the same period at 5.5 per 100 000 and 6.0 per 100 000 in 1965 and 2015, respectively. The increase in incidence was most evident among individuals aged ≥80 years. The incidence of calcium oxalate stones has steadily increased among males and females, whereas that of infection-related stones has significantly decreased from 26.2% to 14.3% among men over the past 50 years. CONCLUSIONS: Nationwide surveys suggest a steady increase in the incidence of lower urinary tract stones over a 50-year period in Japan. This trend might reflect changes in the aging population and improved Japanese medical standards.

Simplified method using kidney / ureter / bladder x-ray to determine the appropriate length of ureteral stents.

PURPOSE: To investigate a method to determine the appropriate length of ureteral stents, given that the stent length may lead to exacerbation of urinary symptoms if the stent crosses the bladder midline. MATERIALS AND METHODS: We retrospectively reviewed the position of the distal curl of the ureteral stent using kidney/ureter/bladder (KUB) radiographs after ureteroscopic lithotripsy in 165 patients who underwent placement of 24- or 26-cm ureteral stents. According to the KUB findings, we categorized the position of the distal curl of the ureteral stent into two groups. In Group 1, the stents did not cross the midline (appropriate length); in Group 2, the stents crossed the midline (inappropriate length). We assessed several patient parameters (sex, height, body mass index, and stone side) and the index of ureteral length using KUB radiographs ("C-P") and computed tomography (CT, "PV"). Multivariate analysis was performed to identify the most significant factors affecting the position of ureteral stents. We also calculated the cutoff points of the receiver operating characteristic (ROC) curve of C-P and P-V for the position of ureteral stents. RESULTS: The multivariate analysis showed that C-P was the most significant factor affecting the position of ureteral stents (p < 0.001) in patients with 24- and 26-cm ureteral stents. Comparison of the ROC curves of C-P and P-V showed that C-P was superior to P-V (p < 0.01) in patients with 24- and 26-cm stents. CONCLUSION: The use of KUB radiographs was effective and simple in determining the appropriate length of ureteral stents.

Simplified method using kidney / ureter / bladder x-ray to determine the appropriate length of ureteral stents

ABSTRACT Purpose: To investigate a method to determine the appropriate length of ureteral stents, given that the stent length may lead to exacerbation of urinary symptoms if the stent crosses the bladder midline. Materials and Methods: We retrospectively reviewed the position of the distal curl of the ureteral stent using kidney/ureter/bladder (KUB) radiographs after ureteroscopic lithotripsy in 165 patients who underwent placement of 24- or 26-cm ureteral stents. According to the KUB findings, we categorized the position of the distal curl of the ureteral stent into two groups. In Group 1, the stents did not cross the midline (appropriate length); in Group 2, the stents crossed the midline (inappropriate length). We assessed several patient parameters (sex, height, body mass index, and stone side) and the index of ureteral length using KUB radiographs ("C-P") and computed tomography (CT, "P-V"). Multivariate analysis was performed to identify the most significant factors affecting the position of ureteral stents. We also calculated the cutoff points of the receiver operating characteristic (ROC) curve of C-P and P-V for the position of ureteral stents. Results: The multivariate analysis showed that C-P was the most significant factor affecting the position of ureteral stents (p < 0.001) in patients with 24- and 26-cm ureteral stents. Comparison of the ROC curves of C-P and P-V showed that C-P was superior to P-V (p < 0.01) in patients with 24- and 26-cm stents. Conclusion: The use of KUB radiographs was effective and simple in determining the appropriate length of ureteral stents.