Ureteral Wall Research Articles

Predicting narrow ureters before ureteroscopic lithotripsy with a neural network: a retrospective bicenter study.

In some patients, the passage of semi-rigid ureteroscopes up the ureter is impossible due to narrow ureteral lumen. We established a neural network to predict the inability of the ureter to accommodate the semi-rigid ureteroscope and the need for active or passive dilatation using non-contrast computed tomography (CT) images. Data were collected retrospectively from two centers of 1989 eligible patients who underwent ureteroscopic lithotripsy with ureteral stones. Patients were categorized into two groups: control and narrow ureter. The network was designed and trained for predicting a narrow ureter during initial ureteroscopic lithotripsy, which integrated multi-scale features of the ureter. The predictive efficacy of neural networks DenseNet3D, ResNet3D, ResNet3D MC, and TimeSformer was compared. Furthermore, a previous ureteroscopy or a history of double-J stent placement, ureteral wall thickness and Hounsfield unit (HU) density of the ureter under the stone were compared. Model performance was assessed based on the accuracy, area under the receiver operating characteristic curve (AUC ROC), etc. The DenseNet3D-based network achieved an AUC ROC score of 0.884 and an accuracy of 85.29%, followed by the ResNet3D-based network, the ResNet3D MC-based network, and the TimeSformer-based network. The DenseNet3D-based network significantly outperformed other candidate predictors. Furthermore, the networks were validated in an external test set. Decision curve analysis showed the clinical utility of the neural network. The neural network provides an individualized preoperative prediction of narrow ureter based on non-contrast CT images, which could be employed as part of a surgical decision-making support system.

Average, and Maximum Ureteral Wall Thickness are Predictor Factor for Ureteroscopy Outcomes?

Objective: The aim of our study is to investigate the effect of average and maximum ureteral wall thicknesses measured by computed tomography before the operation on ureteroscopy results.Materials and Methods: This prospective study was conducted with 103 patients who underwent ureteroscopy for ureteral stones between July and December 2021. The maximum ureteral wall thickness in the region of the ureteral stone and the average of the ureteral wall thicknesses measured from the 3-6-9-12 lines were calculated by non-contrast computed tomography. The operation time, residual stone, double j insertion status, and intraoperative complication status were examined according to the average ureteral wall thickness and maximum wall thickness.Results: Of the 103 patients included in the study, 77 were male, and 26 were female. The mean age of the patients was 43.83±15.11 years. The mean stone length was 10.76±3.84 mm. The average ureteral wall thickness was 3.81±1.24 mm, while the maximum ureteral wall thickness was 4.9±1.8 mm. It was found that as the maximum, and average ureteral wall thickness increased, the operation time, residual stone, double insertion rate, and post-ureteroscopic lesion scale grade increased (p<0.05).Conclusion: Maximum and average ureteral wall thicknesses are predictive factors for ureteroscopy results.

Left-sided flap transposition of the appendix for urethroplasty in oncourology

The ureter is a unique tubular structure, extremely sensitive to exogenous influences and directly affects to renal function. The injuries of the ureter remain one of the most difficult problems requiring an extraordinary surgical approach in urology. Extended strictures and obliterations of the ureters of various origins in the absence of timely treatment are accompanied by irreversible changes in the upper urinary system and renal parenchyma. Obstructive uroteropathy with transformation of the ureter wall, pelvis and kidney parenchyma in the case of oncology disease is caused directly by the tumor itself or invasive growth or complication of treatment. Therefore, the determination of indications and algorithms for ureteral reconstruction are cornerstone problem in urology daily practice.

Renal Dysplasia with Hydronephrosis and Congenital Ureteral Stricture in Two Holstein-Friesian Calves

We investigated the pathological characteristics of renal dysplasia with hydronephrosis and congenital ureteral stricture in two calves. Macroscopically, the affected kidneys were enlarged and the renal calyces were dilated and associated with ureteral strictures. Histopathologically, multifocal regions of mesenchyme were observed in the renal medulla. This mesenchyme was weakly eosinophilic with haematoxylin and eosin, blue with Alcian blue and pale blue with Masson's trichrome, and was immunopositive for vimentin and smooth muscle actin, consistent with persistent mesenchyme. There was asynchronous differentiation of the renal cortex characterized by immature glomeruli, immature tubules and arteriolar proliferation. Similar persistent mesenchyme was observed in the ureteral walls with ureteral stricture, and the ureteral musculature or smooth muscle bundles had a disorganized arrangement. Congenital ureteral stricture appeared to have caused ureteral obstruction and hydronephrosis. The lesions may represent a new phenotype of renal dysplasia with concomitant congenital ureteral stricture in Holstein-Friesian calves.

Flexible ureteroscopy without ureteral access sheath

IntroductionUreteral access sheath (UAS) is widely used in flexible ureteroscopy and laser lithotripsy (FURS) based on better stone-free rates, lower intrarenal pressure and fewer complications. However, it also rises surgical costs and may injure the ureteral wall. The main objective of our study is to compare safety and efficacy of FURS with and without UAS to evaluate whether its use is justified in all cases. Materials and methodsWe performed a retrospective observational analytic study based on a prospective database. A total of 241 consecutive patients who underwent FURS for upper ureter and renal stones between January 2018 and May 2020 were included for analysis and divided into two groups upon UAS use. We compared demographic data, stone characteristics, prestenting, operative time, need for ureteral stent, postoperative urinary tract infection, renal colic and need for ancillary procedures. ResultsA total of 198 patients (82.2%) were included in the group without UAS. Operative time was significantly shorter in the group of patients without UAS than those with UAS (64.6 minutes ± 29.5 vs. 89.9 minutes ± 2.8 respectively; p 0.010). Both groups had similar rates of colic pain and urinary tract infection. Ancillary procedures were more frequent in the UAS group (37.2 vs. 21.2%; p 0.026), but significance was lost in multivariate assessment. ConclusionFURS without UAS seems to be as safe as FURS with UAS but requires less ancillary procedures. An additional advantage is shorter operative time.

Long-term outcomes of paclitaxel-coated balloons for non-malignant ureteral strictures.

To evaluate the clinical efficacy and safety of drug-coated balloon (DCB) ureteroplasty for the management of non-malignant ureteral strictures. A prospective "off-label" monocentric single-arm pilot study investigating the safety and efficacy of drug-coated balloon (DCB) (Lutonix®; BD, USA) was performed. Twenty-five patients with benign ureteral strictures related to uretero-enteric anastomosis (n = 13); lithiasis (n = 5), post-surgical complications (iatrogenic n = 5), transplanted kidney (n = 1) and post-radiotherapy (n = 1) were included. Following lesion crossing, predilatation was performed using 4-7mm high-pressure balloon catheter (5-6Fr) with a balloon pressure of 6-7atm based on the manufacturer's recommendation. In the absence of rupture of the ureteral wall, the DCB was dilated for 4min. across the lesion. The process was repeated if deemed necessary to a maximum of three stricture dilatations. We analysed both clinical and radiological primary patency (no signs of ipsilateral hydronephrosis or improvement of the existing residual dilatation at the follow-up examinations) and secondarily safety endpoints. Mean lesion length was 40 ± 28.5mm. Mean time follow up was 36months ± 10.46months. Strictures were located at upper ureteric (12%), lower ureteric (32%), ureterovesical anastomosis (4%) and uretero-enteric anastomosis (52%) levels. The overall radiological success at 1-year follow-up was 88% (22/25 patients). In 56% patients (14/25 patients with primary patency) the nephrostomy catheter was removed 21days following a single DCB procedure. In 32% (8/25 patients) an additional dilatation sessions were required for maintaining the ureteral patency. The overall failure rate at 1-year follow-up was 12% (3/25 patients). Only one case of febrile urinary tract infection in a female patient (acute pyelonephritis) was encountered after the first dilatation. Paclitaxel-coated balloon ureteroplasty proved to be safe and effective for the treatment of non-malignant ureteral strictures. Larger studies are warranted to validate these promising initial results.

Quantifying particle adhesion to the ureteral walls during peristaltic flow.

In this paper, we investigate the motion of particle(s) under the action of peristaltic flow. The particle trajectories are simulated by considering sinusoidal peristaltic waves. The fluid flow is governed by a two-dimensional Navier-Stokes equation, whereas for the particle dynamics we use the Basset-Boussinesq-Oseen (BBO) equation. The particle trajectories computed for different characteristic peristaltic flows, that is, trapping flow, augmented flow, and backward flow, show that the net horizontal particle displacement is largest for the augmented flow case. In general, the particle motion depends on its location in the peristaltic channel because of the wall curvature, which directly affects the flow velocities. The reported results for a cluster of particles show that whilst a fraction of particles form a group and propagate along the wave, some particles are left behind that deposit on the channel wall. In many biological processes it is desirable to know the number of particles that accumulate on the channel walls. In the present work, we propose empirical relations which can be used to calculate particle adhesion as a function of time.

Effective ureteral access sheath insertion during flexible ureteroscopy: Influence of the ureteral orifice configuration.

We sought to determine the possible predictors for effective insertion of the ureteral access sheath (UAS) during flexible ureteroscopy (fURS) in virgin ureters and their impact on postoperative ureteral wall injury and the procedural outcome. A retrospective review of prospectively collected data was performed for all consecutive patients scheduled for fURS of virgin ureters at two tertiary care centers between 2018 and 2020. Demographics, stone characteristics, and perioperative data, including the configuration of the ureteral orifice (UO) over introductory guidewire insertion, were collected. Multivariate logistic regression was used to detect possible predictors of successful UAS insertion. In total, 128 patients who underwent primary fURS were included, with a mean age of 43.3±12.3 years and a stone burden of 12.3±6.9 mm. One hundred and ten patients (85.9%) achieved successful ureteral access insertion, including 81 (63.3%) without ureteral dilatation and 35 with dilation, of which 29 (22.7%) had a successful UAS afterward, while six failed. Total patients who underwent ureteral orifice dilatation were 35. 29 had a successful UAS afterward, while 6 failed. Patients who underwent successful UAS placement into virgin ureters were significantly older and had a lower body mass index (BMI). A tent-shaped UO over the guidewire led to successful UAS insertion. In multivariate regression analysis, cases with BMI <30 kg/m2 (odds ratio [OR] 1.89, 95% confidence interval [CI] 1.28-7.03) and those with a tent-shaped UO over the introductory guidewire (OR 6.60, 95% CI 3.8-7.2) maintained their significance to predict successful UAS insertion into virgin ureters. Nine patients (8.2%) had ureteral mucosal injuries, and the overall stone-free rate was 78.2%. Patients with normal BMIs and tent-shaped UOs over the introductory guidewires are more likely to achieve primary UAS insertion without the need for ureteral dilation.

A novel model using computed tomography parameters to predict shock wave lithotripsy success in ureteral stones at different locations

ObjectiveTo combine non-contrast computerized tomography (NCCT)-based parameters with stone and patient characteristics that are already known to affect shock wave lithotripsy (SWL) success and assess this novel model’s effectiveness in predicting SWL success for single ureteral stones in different locations. Materials and methodsData of patients treated by SWL for a single ureteral stone between January 2017 and January 2019 were retrospectively reviewed. Demographic parameters of patients and stone characteristics were combined with NCCT-based parameters. NCCT-based parameters included the presence or absence of hydronephrosis, perinephric stranding, periureteral edema, diameter of the proximal ureter, ureteral wall thickness (UWT) at ureteral stone site. The logistic regression method was used for the development of a useful predictive model. Subsequently, the receiver operating curve was used to determine cut-off levels, and a scoring system was developed for prediction of SWL success. ResultsStone-free rate was 77,1% (267/346) in the entire cohort. Univariate analysis revealed that age, stone volume, density, perinephric stranding, diameter of proximal ureter, and UWT, were associated with SWL success. In multivariate analysis, proximal ureteral stone location, stone volume, density, and UWT were independent predictors of SWL success. The formula used during logistic regression analysis was: 1/[1 + exp {−8.856 + 0.008 (stone volume) + 0.002 (stone density) + 0.673 (UWT) + 1026 (proximal ureteral stone)}]. The scores of 0, 1, 2, 3 and 4 were associated with 97,8%, 83,4%, 60,8%, 33,2% and 11,1% success rates, respectively, in the prediction model based on these parameters. ConclusionWe conclude that our model can facilitate decision-making for SWL treatment of ureteral stones in different locations.

An Unexpected Finding in a Patient with Suspected Urothelial Recurrence during Surveillance Post Radical Cystoprostatectomy for Urothelial Bladder Carcinoma

We report a 79-year-old gentleman with an asymptomatic intra-ureteric encrusted suture thread. He was found to have calcification in the left renal pelvis and thickening of the upper ureteric wall on a follow-up computerised tomography (CT) scan ten years after a radical cystoprostatectomy and ileal conduit formation for bladder and prostate cancer. These incidental CT scan findings raised the possibility of either ureteric stone or tumour. Subsequently, the patient underwent a ureterorenoscopy, which revealed a calcified 6cm length thread thought to be a suture that slipped intraoperative during his initial radical surgery ten years earlier.

Ureteroscopia flexible sin vaina de acceso ureteral

IntroductionUreteral access sheath (UAS) is widely used in flexible ureteroscopy and laser lithotripsy (FURS) based on better stone-free rates, lower intrarenal pressure and fewer complications. However, it also rises surgical costs and may injure the ureteral wall. The main objective of our study is to compare safety and efficacy of FURS with and without UAS to evaluate whether its use is justified in all cases. Materials and methodsWe performed a retrospective observational analytic study based on a prospective database. A total of 241 consecutive patients who underwent FURS for upper ureter and renal stones between January 2018 and May 2020 were included for analysis and divided into two groups upon UAS use. We compared demographic data, stone characteristics, prestenting, operative time, need for ureteral stent, postoperative urinary tract infection, renal colic and need for ancillary procedures. ResultsA total of 198 patients (82.2%) were included in the group without UAS. Operative time was significantly shorter in the group of patients without UAS than those with UAS (64.6 minutes ± 29.5 vs. 89.9 minutes ± 2.8 respectively; p 0.010). Both groups had similar rates of colic pain and urinary tract infection. Ancillary procedures were more frequent in the UAS group (37.2 vs. 21.2%; p 0.026), but significance was lost in multivariate assessment. ConclusionFURS without UAS seems to be as safe as FURS with UAS but requires less ancillary procedures. An additional advantage is shorter operative time.

УСОВЕРШЕНСТВОВАНИЕ МЕТОДА ЭКСТРАВЕЗИКАЛЬНОЙ РЕИМПЛАНТАЦИИ МОЧЕТОЧНИКА

Objective: To optimize the technique of extravesical ureteral reimplantation in experimental animals. Methods: Experiments were carried out on 21 Flanders rabbits. Initially, ureterohydronephrosis (UHN) was modeled by alcoholization of the ureter in its vesical part according to the method of Ya.V. Gudynsky. After 21 days, the animals underwent extravesical ureteral reimplantation using the technique optimized by the team of urologists. Results: The stents were removed endoscopically on the 20th day. In order to exclude vesicoureteral reflux, contrast cystography was performed, in which reflux was not detected. To exclude obstruction, on the 30th, 60th, and 90th days after the operation, an ultrasound scanning of the urinary system was performed, in which the presence of UHN was not noted. On the 90th day, the experimental animals underwent resection of the anastomotic zone for histological examination. It was found that the diameter of the transplanted segment corresponded to the normal size of the rabbit ureter, there was a slight thickening of the ureteric wall, its hypertrophy, and intracellular hyperplasia. Conclusion: The effectiveness and safety of the proposed method of extravesical ureteral reimplantation with antireflux protection has been experimentally proven. Keywords: Ureter, urodynamics, obstruction, ureterohydronephrosis, megaureter.

Is it possible to predict spontaneous passage of a ureteral stone? An up-to-date comment on the current problem with new concepts concerning the patient and the stone.

The aim of this article was to determine a predictive factor by examining the patient's characteristics and the stone to predict the ureteral stone spontaneous passage. A total of 200 patients aged 18-55 who were referred with middle and distal ureter ureteral stones between 5-7 mm were analyzed retrospectively. Patients were randomized as 50 spontaneous stone passage positive (SSPP) and 50 negative patients. Body mass index (BMI), waist-to-hip ratio (WHR), stone size, ureter length, ureter diameter, stone Hounsfield unit value (SHU), ureteral wall thickness (UWT), kidney parenchymal thickness (KPT), kidney parenchymal density, neutrophil-lymphocyte ratio (NLR) and thrombocyte-lymphocyte ratio (TLR) values were recorded. The average SHU of the SSPP group was 579 and 970 in the negative group (p: 0.000). While the mean was 1.7 mm in the UWT SSPP group, it was 2.4 mm in the negative group (p: 0.000). SHU and UWT were statistically significantly different in univariate and multivariate logistic regression analyses. WHR values were 39.6 and 29.3 for SSPP and the negative group, respectively (p: 0.032). The ureter diameter was 7.6 mm for the SSPP group and 8.9 mm in the negative group (p: 0.01). Low SHU value is related to the ureteral stone's positive spontaneous passage, and the increase of UWT is inversely related to the spontaneous passage. WHR is higher in people who can passage ureteral stones. A narrow ureter diameter is correlated with spontaneous stone passage. Ureter length, KPT, and kidney parenchymal density were not associated with spontaneous passage.

Evaluation of PGP 9.5, NGFR, TGFβ1, FGFR1, MMP-2, AT2R2, SHH, and TUNEL in Primary Obstructive Megaureter Tissue.

Primary obstructive megaureter (POM) morphogenesis is not fully known. The aim of the study was to evaluate the appearance of different factors that might take part in the pathogenesis of POM. Megaureter tissues of 14 children were stained with hematoxylin and eosin as well as with immunohistochemistry for protein gene product 9.5, nerve growth factor receptor, transforming growth factor beta 1 (TGFβ1), fibroblast growth factor receptor 1 (FGFR1), matrix metalloproteinase 2 (MMP-2), angiotensin 2 receptor type 2, and sonic hedgehog (SHH) protein. Apoptosis was detected by terminal dUTP nick-end labeling reaction. POM tissues revealed transitional epithelium with scattered vacuolization, submucosa with inflammatory cells, and focally vacuolized and chaotically organized muscle layers. Apoptosis, appearance of MMP-2, FGFR1, and SHH prevailed, but TGFβ1 positive cell number was lower in patients. Correlation between MMP-2 in epithelium and endothelium, FGFR1 and MMP-2 in epithelium, and TGFβ1 in epithelium and connective tissue in patients was detected. POM morphopathogenesis involves an apoptotic cell death of epithelium and smooth muscle as well as tissue degradation in epithelium and connective tissue of the ureter wall. The decrease of tissue growth through diminished TGFβ1 expression and stimulation of FGFR1 and MMP-2 suggests a disbalance of tissue remodelation in the megaureter wall.

Mathematical Model Represents the Effect of Flexible Endoscopy on Suspension Fluid Flow

In this manuscript, peristaltic transport induced by a sinusoidal traveling wave in the case for a viscous incompressible Newtonian fluid mixed with rigid spherical particles in the presence of a flexible inner tube, where the inner tube is also moving with a sinusoidal traveling wave of moderate amplitude is studied. The governing equations of the mixture (fluid-particle suspension) are written in two-dimensional cylindrical coordinates. The long-wavelength approximation is used to simplify the system of equations (d&lt;&lt;1). The velocities distribution for both fluid and particles are obtained and evaluated numerically with discussion for special cases. The flow rate, pressure drop, friction forces and shear stress at the outer and inner walls of tubes are derived and represented graphically. In the urinary system, peristalsis is due to involuntary muscular contractions of the ureter wall which drives urine from the kidneys to the bladder through the ureters. A mathematical analysis of peristaltic flow with application to the ureter in presence of flexible endoscopy (Peristaltic Endoscope) is taken as a real application in this study. Finally, conclusions of the research and recommendations for future work are discussed. The results obtained may be relevant to the transport of other physiological fluids and industrial applications in which peristaltic pumping is used.

Primary adenocarcinoma of renal pelvis or ureter: an uncommon histopathological entity seen in three cases

BackgroundPrimary adenocarcinoma of renal pelvis or ureter is rarest (< 1%) among all urothelial tumors. Regrettably, no characteristic symptoms, radiological features and treatment for this tumor are reported. We report three cases of adenocarcinoma of renal pelvis and ureter.Case presentationCase 1 had grossly hydronephrotic non-functional right kidney and underwent percutaneous nephrostomy followed by laparoscopic simple nephrectomy. Incidentally, histopathological examination reported adenocarcinoma of renal pelvis. Whole-body positron emission tomography-CT (PET-CT) ruled out malignancy at other sites. Patient refused adjuvant chemotherapy. Case 2 presented with previous history of right pyelolithotomy, right ureteroscopic lithotripsy and right flank pain with intermittent discharge via previous percutaneous site. On biochemical and radiological investigations, right poorly functioning pyonephrotic kidney was confirmed. Patient underwent right open nephrectomy which incidentally reported adenocarcinoma of renal pelvis. Patient is disease-free at 18 months of follow-up. Case 3 had left ureteric wall thickening on CT scan when evaluated for hematuria. Ureteroscopic-guided biopsy showed villous adenoma. Laparoscopic left nephroureterectomy with bladder cuff excision specimen showed well-differentiated adenocarcinoma in ureter with extension into periureteric fat. Patient died 32 months after surgery.ConclusionPrimary adenocarcinoma of renal pelvis or ureter is very rare and urologists should suspect it in patients with mucinous material in nephrostomy tube. We should have a low threshold for performing radical nephrectomy with complete ureterectomy in these unusual cases to improve the prognosis.

The predictive value of ureteral wall area for impacted ureteral stones

Objective: To investigate the clinical indicators for preoperative prediction of impacted ureteral stones and analyze the predictive value of ureteral wall area(UWA). Methods: A total of 197 patients who underwent ureteroscopic lithotripsy due to ureteral stones at our institution from January to December 2020 were retrospectively analyzed. Preoperative patient age, gender, body mass index (BMI), history of hypertension, diabetes mellitus, side of stone, location of stone, maximum diameter of stone, CT value of stone, C-reactive protein (CRP), creatinine, renal pelvis diameter, ureteral wall thickness and UWA were collected. Patients were divided into impacted and non-impacted groups according to whether the stones were impacted intraoperatively. Univariate analysis was used to compare the differences in each clinical indicator between the two groups, and multivariate logistic regression was performed to analyze the independent predictors of impacted stones for those with differences. The receiver operating characteristic (ROC) curve was used to analyze the predictive power of each independent predictor, and the Delong test was used to analyze whether the difference in the area under the curve (AUC) of each independent predictor was statistically significant. Results: All 197 patients successfully completed the operation, aged 51 (36, 56) years; 137 males and 60 females. According to the results of ureteroscopy, they were divided into 82 cases of impacted ureteral stones and 115 cases of non-impacted ureteral stones. Univariate analysis showed that there were significant differences in maximum stone diameter, stone CT value, renal pelvis diameter, ureteral wall thickness and ureteral wall area between the two groups (P<0.05); There was no significant difference in age, gender, BMI, history of hypertension, diabetes, stone side, location of stone, CRP and creatinine (P>0.05). Multivariate logistic regression analysis showed that stone CT value (P<0.01), ureteral wall thickness (P<0.001) and ureteral wall area were independent predictors of impacted ureteral stones (P<0.001). The ROC curve was used to compare the predictive efficacy of independent predictors of stone CT value, ureteral wall thickness and ureteral wall area. The area under the ureteral wall area curve was the largest (AUC = 0.901, 95%CI: 0.859-0.943, P<0.001), followed by ureteral wall thickness (AUC = 0.799, 95%CI: 0.736-0.862, P<0.001) and stone CT value (AUC = 0.700, 95%CI: 0.626-0.775, P<0.001). By Delong test, there were significant differences in AUC between ureteral wall area and stone CT value (Z=4.527, P<0.001) and ureteral wall thickness (Z=3.407, P<0.001). The best predictive value of ureteral wall area was 79.6 mm2. The sensitivity and specificity of this critical value for predicting ureteral incarcerated calculi were 80.1% and 89.5%. Conclusions: The UWA, ureteral wall thickness as well as the CT value of stones were all independent predictors of impacted ureteral stones, and UWA had a better predictive value.

Modelo novedoso basado en los parámetros de la tomografía para predecir el éxito de la litotricia por ondas de choque en los cálculos ureterales de diferentes localizaciones

ObjectiveTo combine non-contrast computerized tomography (NCCT)-based parameters with stone and patient characteristics that are already known to affect shock wave lithotripsy (SWL) success and assess this novel model's effectiveness in predicting SWL success for single ureteral stones in different locations. Materials and methodsData of patients treated by SWL for a single ureteral stone between January 2017 and January 2019 were retrospectively reviewed. Demographic parameters of patients and stone characteristics were combined with NCCT-based parameters. NCCT-based parameters included the presence or absence of hydronephrosis, perinephric stranding, periureteral edema, diameter of the proximal ureter, ureteral wall thickness (UWT) at ureteral stone site. The logistic regression method was used for the development of a useful predictive model. Subsequently, the receiver operating curve was used to determine cut-off levels, and a scoring system was developed for prediction of SWL success. ResultsStone-free rate was 77,1% (267/346) in the entire cohort. Univariate analysis revealed that age, stone volume, density, perinephric stranding, diameter of proximal ureter, and UWT, were associated with SWL success. In multivariate analysis, proximal ureteral stone location, stone volume, density, and UWT were independent predictors of SWL success. The formula used during logistic regression analysis was: 1/[1+exp {-8.856+0.008(stone volume)+0.002 (stone density)+0.673 (UWT)+1026 (proximal ureteral stone)}]. The scores of 0, 1, 2, 3 and 4 were associated with 97,8%, 83,4%, 60,8%, 33,2% and 11,1% success rates, respectively, in the prediction model based on these parameters. ConclusionWe conclude that our model can facilitate decision-making for SWL treatment of ureteral stones in different locations.

Intraureteral Indocyanine Green (ICG) in Benign Gynecologic Surgery

<h3>Study Objective</h3> To demonstrate the use of intraureteral indocyanine green (ICG) in gynecologic surgery <h3>Design</h3> Educational video highlighting a surgical technique. <h3>Setting</h3> Academic medical center. <h3>Patients or Participants</h3> Women undergoing laparoscopic pelvic surgery for benign gynecologic indications including both conventional and robotic approaches. We use this in our practice in cases where significant distortion of anatomy from presenting pathology is anticipated or in the setting of patient factors including multiple prior surgeries, radiation, active inflammation, or congenital anomalies. <h3>Interventions</h3> At the start of the procedure, rigid cystoscopy is performed using a 22 French rigid cystoscope. We combine 25 mg of ICG with 10 mL of sterile water (concentration of 2.5 mg/mL). A 5 French ureteral catheter is passed into the ureter up to 20 cm and 5 mL of ICG is gradually injected as the catheter is slowly withdrawn. This process is repeated in the contralateral ureter. Using specialized equipment, near infrared light or laser penetrates the ureter causing the ICG molecules fluoresce and emit near infrared light that is captured and electronically converted to give the ureter a green color. <h3>Measurements and Main Results</h3> The fluorescence of the ICG allows for quick identification of the ureter. The catheter used may have a smallerdiameter than stents, potentially reducing risk of ureteral edema, injury, and obstruction. Indwelling stents also have greater likelihood of thinning the ureteral wall. ICG allows for detection of small full thickness injury that may be missed by stents as extravasation will present in the surrounding tissues. There are fewer externalized foreign bodies intraoperatively for a shorter duration of time, potentially reducing risk of infection or inadvertent injury. Limitations include the need for specialized equipment and possible washout effect with ICG used intravenously or intracervically. <h3>Conclusion</h3> Intraureteral ICG helps identify the ureter intraoperatively during benign gynecologic surgery with low risk of complications and potential benefits in comparison to stents.

Ureteral wall thickness at the stone site: A critical predictor of success and complications in children undergoing semi-rigid ureteroscopy

We retrospectively assessed the role of ureteral wall thickness (UWT) at the ureteral stone site in predicting the stone-free status and the complication rates in children undergoing semi-rigid ureterorenoscopy (URS). The children who underwent URS and had undergone non-contrast abdominal computerized tomography before the URS were included in the study. The following protocol was used to determine the outcome. Immediately before removing the stent, all children were evaluated by ultrasound (US) and plain film (KUB) for residual stones in the upper urinary tract and after removing the double J stent, the presence of stone fragments in the ureter was checked with URS. The children were considered stone-free if no residual fragments were identified in radiologic imaging and the evaluation of the ureter by URS. The case was accepted as a failure if any fragments were seen on immediate US, KUB, and/or during URS just after the stent removal. The patients who could not complete the standard primary URS procedure due to stone-related reasons (patients for whom we could not pass the safety guidewire behind the stone and/or the procedure was terminated due to pyuria during the procedure) were also accepted as a failure. The possible factors related to the patient, stone, ureter, and the operation that could affect the outcome and the complications following the URS were evaluated. The children's median age was six years (1-17 years). Among the 89 children included in the study, 69 (78%) were stone-free, and 20 (22%) presented residual stone after the first URS session. The ROC analysis revealed that a UWT value of 4.5mm (sensitivity 60%, specificity 92%) was the optimal cut-off value predictive of the URS outcome. The regression analysis revealed UWT >4.5mm (p=0.006) and multiple stone presentation (p=0.005) as independent risk factors for residual stone. Complications were detected in 15 (17%) children. Thick ureteral wall (p=0.012) and longer operative time (p=0.016) were defined as the independent risk factors for complications. Increased UWT is associated with the adverse outcomes of URS due to tissue hypertrophy, edema, and mucosal bleeding may cause difficulty in removing the stone. The thick ureteral wall might increase the risk of complications due to the necessity of manipulating the instruments or the involuntary forceful use of instruments while removing the stone. UWT was the only independent variable affecting both increased failure and complication rates in children undergoing URS.