Ureteral Diameter Research Articles

One Trocar-Assisted Retroperitoneoscopic Ureteroureterostomy for Ureteral Duplication.

Aim: To describe the operative technique and outcome of one trocar-assisted retroperitoneoscopic ureteroureterostomy (OTAU) in 40 cases of complete ureteral duplication in children. Patients and Methods: From September 2016 to December 2020, 40 patients (12 male and 28 female) less than 10 years of age underwent OTAU. A transverse skin incision of 12 mm in length was created approximately 1 cm above the iliac crest. Muscle was spared and retracted with stay sutures to expose the retroperitoneal space. Subsequently, a balloon trocar was then inserted, and pneumoperitoneum was achieved. A 10 mm operating laparoscope (Stema, Germany) with a Maryland was used to dissect and isolate the ureters from surrounding tissues. The ureters were then exteriorized and end-to-side ureteroureterostomy was performed using Polydioxanone (PDS) 6/0 running sutures. Patient's demographic, operative, and follow-up data were collected prospectively. Results: The mean age of patients was 25.2 months (range: 1-105 months). The mean operating time was 81.9 ± 11.3 minutes. There were no intraoperative conversions or complications. After a median follow-up time of 47.5 months, the differential renal function of the pathological upper pole moiety (UPM) was preserved in all patients. Ultrasound revealed a significant reduction in UPM's renal pelvis anterior-posterior diameter from 19.6 ± 9.1 mm preoperatively to 11.1 ± 6.7 mm postoperatively (p < 0.05), accompanied by a reduction in ureter's diameter from 10.8 ± 4.4 mm to 4.8 ± 1.2 mm (p < 0.05). Overall, all 32 patients with preoperative symptoms experienced complete symptom resolution. Conclusion: OTAU is a safe and feasible approach that yields excellent outcomes for complete ureteral duplication.

Radiological signs of stone impaction add no value in predicting spontaneous stone passage

Stone size and location are key factors in predicting spontaneous stone passage (SSP), but little attention has been paid to the influence of radiological signs of stone impaction (RSSI). This research aims to determine whether RSSI, alongside stone size, can predict SSP and to evaluate the consistency of ureteral wall thickness (UWT) measurements among observers. In this retrospective study, 160 patients with a single upper or middle ureteral stone on acute non-enhanced computed tomography (NCCT) were analysed. Patient data were collected from medical records. Measurements of RSSI, including UWT, ureteral diameters, and average attenuation above and below the stone, were taken on NCCT by four independent readers blind to the outcomes. The cohort consisted of 70% males with an average age of 51 ± 15. SSP occurred in 61% of patients over 20 weeks. The median stone length was 5.7 mm (IQR: 4.5–7.3) and was significantly shorter in patients who passed their stones at short- (4.6 vs. 7.1, p < 0.001) and long-term (4.8 vs. 7.1, p < 0.001) follow-up. For stone length, the area under the receiver operating characteristic curve (AUC) for predicting SSP was 0.90 (CI 0.84–0.96) and only increased to 0.91 (CI 0.85–0.95) when adding ureteral diameters and UWT. Ureteral attenuation did not predict SSP (AUC < 0.5). Interobserver variability for UWT was moderate, with ± 2.0 mm multi-reader limits of agreement (LOA). The results suggest that RSSI do not enhance the predictive value of stone size for SSP. UWT measurements exhibit moderate reliability with significant interobserver variability.

CT-Based Predictors of Spontaneous Ureteral Stone Passage.

To assess CT-scan based parameters, particularly ureteral wall thickness (UWT), in predicting spontaneous ureteral stone passage. Cross-sectional, analytical study. Place and Duration of the Study: Section of Urology, Department of Surgery, The Aga Khan University Hospital, Karachi, Pakistan, from June to November 2023. Patients with symptomatic, single, radio-opaque, unilateral ureteral stones having size ≤10 mm with normal kidney functions, diagnosed by non-contrast CT-scan KUB, and treated by conservative option for four weeks were enrolled. Clinical and radiological predictors for stone passage (SP), including stone size, area, laterality, location, density, degree of hydronephrosis, maximal UWT at the stone site, and ureteral diameter and density above and below the stone, were evaluated. Binary logistic regression analysis was employed to identify predictors of stone passage. Receiver operating characteristic (ROC) curve was used to find the optimal cut-off for UWT. Among 34 eligible patients, 22 (64.7%) passed their stones spontaneously. Patients who passed had smaller stone size and area and lesser UWT. Stone location, laterality, degree of hydronephrosis, stone density, ureteral wall diameter, and density above and below stones were not associated with SP. Multivariate analysis revealed maximum UWT as the independent predictor of SP, with a cut-off of 1.95 mm and an accuracy of 0.94. UWT was the single most convincing factor for the spontaneous passage of ureteral stone in this study. By applying UWT's optimal cut-off value, it might be an extremely significant tool when taking decisions in daily practice. Ureteral wall thickness, Medical expulsive therapy, Non-contrast computed tomography.

Risk and protective factors for secondary procedures after endoscopic dilatation of primary obstructive megaureters.

High-pressure balloon dilatation (HPBD) of the ureterovesical junction with double-J stenting is a minimally invasive alternative to ureteral reimplantation or cutaneous ureterostomy for first-line surgical treatment of primary obstructive megaureter (POM). The aim of our study was to identify the risk factors associated with the need for secondary procedures due to HPBD failure. Prospective data were collected from patients who underwent HPBD for POM between 2007 and 2021 at a single institution. The collected data included patient demographics, diagnostic modalities, surgical details, results, and follow-up. Multivariate logistic regression analysis was performed. Fifty-five ureters underwent HPBD for POM in 50 children, with a median age of 6.4months (IQR: 4.5-13.8). Nineteen patients (37.25%) underwent secondary ureteric reimplantation, with a median of 9.8months after primary HBPD (95% CI 6.2-9.9). The median follow-up was 29.4months (IQR: 17.4-71). Independent risk factors for redo-surgery in a multivariate logistic regression model were: progressive ureterohydronephrosis (OR = 7.8; 95% CI 0.77-78.6) and early removal of the double-J stent. A risk reduction of 7% (95% CI 2.2%-11.4%) was observed per extra-day of catheter maintenance. The optimal cut-off point is 55days, ROC curve area: 0.77 (95% CI 0.62-0.92). Gender, distal ureteral diameter, pelvis diameter, dilatation balloon diameter and preoperative differential renal function did not affect the need for reimplantation. The use of a double-J stent for at least 55days seems to avoid the need for a secondary procedure. Therefore, we recommend removing the double-J catheter at least 2months after the HBPD.

Ureteral endometriosis: MR imaging appearance for predicting complex procedures

Rationale and objectivesTo describe MRI characteristics of ureteral endometriosis (UE) in identifying intrinsic involvement of the ureteric wall and predicting complex procedures. MethodsThirty-three UE lesions in 30 patients treated for UE over a 20-year period were reviewed. A systematic analysis of 13 MRI (ureteric wall thickening, circumference, T1 signal, T2 signal, ureterectasis, lateral parametrial endometriosis (LPE), rectal endometriosis, the foregoing three-characteristic diameter, ovarian endometriomas, adenomyosis, paraurethral endometriosis) and 5 clinical (age, BMI, CA125, creatinine and rAFS stage) characteristics was performed. MRI results were compared to histology and surgical procedure performed (simple versus complex ureteral procedures). ResultsTwenty-five extrinsic and 8 intrinsic UE were pathologically identified. Twenty lesions underwent a simple procedure, and 12 underwent a complex procedure, with 1 ureteroscopic biopsy. There were significant differences in the characteristics of ureteric wall thickening, the diameter of dilated ureter and LPE, rectal endometriosis and adenomyosis between extrinsic and intrinsic UE (p < 0.05). UE was associated with LPE (p = 0.033). The criteria of ureteral wall thickening more accurately predicted intrinsic UE than circumference, but the AUC was not significant difference (AUC, 0.806 and 0.639; 95 % CI, [0.594, 0.937] and [0.419, 0.823], respectively; p = 0.350). There were significant differences in creatinine, thickening and adenomyosis between the simple and complex procedures (p < 0.05). In 11 lesions with the absence of ureterectasis, 4 lesions with hydronephrosis and thickening were intrinsic and underwent complex procedures, while 7 lesions extrinsic and simple. ConclusionsUreteric wall thickening as a analytical criterion may accurately predict intrinsic UE and complex ureteric procedures.

Robot-assisted laparoscopic ureteroureterostomy in a child with upper urinary tract duplication

Upper urinary tract duplication remains one of the most challenging pediatric urology conditions. Various operative methods are used in the treatment of children with this pathology; however, reoperation rate remains high. This study aimed to investigate a case of successful robot-assisted laparoscopic ureteroureterostomy and discuss the technical aspects of this procedure and review known series of robotic ureteroureterostomy. The authors retrospectively reviewed the medical history of a child with duplication of the right kidney, accompanied by reflux of urine into the lower segment collecting system. Surgical intervention was performed using robot-assisted technology. Using computed tomography and voiding cystourethrography, duplex kidney with vesicorenal reflux into the lower segment was diagnosed. The surgical technique used was ureteroureterostomy. The donor ureter was divided in the area of the intended anastomosis. Then, a surgical incision was made in the recipient ureter, the length of which was equal to the diameter of the donor ureter. After preparation of the ureters, an end-to-side anastomosis was performed. The operation was successfully performed without intraoperative difficulties or complications and lasted for 140 minutes. The robot installation time (docking time) was 20 minutes, and the main console time was thus 120 minutes. The patient started feeding on the same day after the operation. The drainage tube was removed after a control ultrasound examination on postoperative day 2. The stent remained in the recipient ureter until its removal 6 weeks after surgery. The duration of follow-up was 6 months. The patient was asymptomatic throughout the control period. Repeated ultrasound examination performed after surgery showed a decrease in the anteroposterior diameter of the lower segment pelvis to 5 mm. Blood flow in the upper and lower segments of the right kidney was not impaired. The advantages of the robotic approach, including improved instrument dexterity and 3D visualization, make it a safe and effective alternative to open or laparoscopic surgery in children.

CT-based radiomics for predicting success of shock wave lithotripsy in ureteral stones larger than 1cm.

This study aims to investigate the predictive value of CT-based radiomics in determining the success of extracorporeal shock wave lithotripsy (SWL) treatment for ureteral stones larger than 10mm in adult patients. A total of 301 eligible patients (165/136 successful/unsuccessful) who underwent SWL were retrospectively evaluated and divided into a training cohort (n = 241) and a test cohort (n = 60) following an 8:2 ratio. Univariate analysis was performed to assess clinical characteristics for constructing a nomogram. Radiomics and conventional radiological characteristics of stones were evaluated. Following feature selection, radiomics and radiological models were constructed using logistic regression (LR), support vector machine (SVM), random forest (RF), K nearest neighbor (KNN), and XGBoost. The models' performance was compared using metrics such as the area under the receiver operating characteristic curve (AUC), precision, recall, accuracy, and F1 score. Finally, a nomogram was created incorporating the best image model signature and clinical predictors. The SVM-based radiomics model showed superior predictive performance in both training and test cohorts (AUC: 0.956, 0.891, respectively). The nomogram, which combined SVM-based radiomics signature with proximal ureter diameter (PUD), demonstrated further improved predictive performance in the test cohort (AUC: 0.891 vs. 0.939, P = 0.166). Integration of CT-derived radiomics and PUD showed excellent ability to predict SWL treatment success in patients with ureteral stones larger than 10mm, providing a promising approach for clinical decision-making.

The impact of the distal ureteral diameter ratio, bladder volume at onset of vesicoureteral reflux, and/or grade in predictive models of clinical outcomes in children with vesicoureteral reflux

Vesicoureteral reflux (VUR) grade has been used as a primary factor in assessing a child's risk of clinical outcomes. Unfortunately, grade has poor inter-observer reliability. We hypothesized that more objective and reliable VCUG parameters including the distal ureteral diameter ratio (UDR) and volume at onset of VUR (Vol) may either augment or replace the current grading system to provide more reliable prediction of clinical outcomes. Multivariate clinical outcome models were analyzed to assess the impact on predictive accuracy by the addition of voiding cystourethrogram (VCUG) data including grade, UDR, and Vol, alone or in combinations. Clinical variables from retrospective review of 841 children's records included age, gender, presentation, VUR laterality, bowel and bladder dysfunction, history of febrile urinary tract infection (UTI), and number of UTIs. The primary outcomes assessed included VUR resolution or persistence and need for operative intervention. Grade, UDR, and Vol were independent predictors of resolution and operative intervention. Vol increased predictive accuracy in resolution models with grade or UDR alone; however, no significant difference occurred in models with the substitution of grade with UDR. A more reliable classification system for VUR, with improved predictive accuracy regarding clinical outcomes, may be developed incorporating UDR and Vol. Whether VUR grade can be completely replaced by Vol and UDR measurements requires further evaluation with larger number of patients.

Single-port-plus-one robot-assisted laparoscopic Lich–Gregoir direct nipple ureteral extravesical reimplantation in pediatric primary obstructive megaureter, comparing to laparoscopic cohen

PurposeTo compare the effects of a single-port-plus-one robotic laparoscopic-modified Lich–Gregoir direct nipple approach and traditional laparoscopic Cohen in treating pediatric primary obstructive megaureter.Materials and methodsThe clinical data of 24 children with primary obstructive megaureter from January 2021 to November 2021 were analyzed retrospectively. Among them, 12 children (8 boys and 4 girls, the average age were 17.17 ± 6.31 months) treated with the laparoscopic Cohen method were defined as group C. The remaining 12 children (7 boys and 5 girls, the average age was 17.33 ± 6.99 months) underwent single-port-plus-one robotic laparoscopic-modified Lich–Gregoir direct nipple ureteral extravesical reimplantation were defined as group L. The parameters of pre-operation, intraoperative and postoperative were compared.ResultsThere were no differences in the patient characteristics and average follow-up time between the two groups (P > 0.05).The obstruction resolution rate was 100% in both groups. The total operation time in group L is slightly longer than that in group C(P < 0.001),but the intraperitoneal operation time of the two groups was comparable(P > 0.05). The postoperative parameters included blood loss, gross haematuria time, indwelling catheterization time and hospitalization time in group L is shorter than group C(P < 0.05). One year post-operation, decreasing in ureteral diameter and APRPD, and increasing in DRF were remarkably observed in both two groups(P < 0.05). Ureteral diameter, APRPD, and DRF were not significantly different both in pre-operation and post-operation between Group L and Group C(P > 0.05).ConclusionSingle-port-plus-one robot-assisted laparoscopic-modified Lich–Gregoir direct nipple approach and traditional laparoscopic Cohen are both dependable techniques for ureteral reimplantation in the treatment of pediatric primary obstructive megaureter. Since Lich–Gregoir can preserve the physiological direction of the ureter and direct nipple reimplantation enhances the effect of anti-refluxing, this technique is favorable for being promoted and applied in robot surgery.

Comparative analysis of laparoscopic and open ureteroureterostomy for the treatment of pediatric duplicated kidneys: a clinical efficacy and safety study.

Duplicated kidneys, though rare, are common in pediatric urinary issues. For children with complete kidney duplication and symptoms or complications, surgery is often needed. Ureteroureterostomy (UU) is a common procedure for this condition. This study aims to evaluate and compare the clinical efficacy and safety of laparoscopic ureteroureterostomy (LUU) and open ureteroureterostomy (OUU) in the treatment of pediatric duplicated kidneys. A retrospective study at Children's Hospital of Anhui Province from February 2017 to January 2023 included pediatric patients who underwent LUU or OUU for completely duplicated kidneys. Comparative measures included operative time, postoperative hospital stay, intraoperative blood loss, pre- and postoperative renal pelvis anteroposterior diameter, pre- and postoperative upper renal parenchymal thickness, pre- and postoperative upper ureteral diameter, and postoperative complications. There are 30 patients, 20 in the LUU group and 10 in the OUU group. All patients underwent surgery successfully, with no conversions to open surgery in the LUU group. Comparison between the LUU group (average age 3.7±3.4 years) and the OUU group (average age 1.6±1.3 years) showed that laparoscopic surgery had a mean duration of 178.8±60.71 min, intraoperative blood loss of 4.3±0.92 mL, drainage tube removal time of 1.8±0.6 days, and postoperative hospital stay of 4.2±2.2 days. In contrast, the OUU group had a mean surgery duration of 181.6±37.8 min, drainage tube removal time of 2.3±0.7 days, intraoperative blood loss of 6.4±4.06 mL, and postoperative hospital stay of 5.8±1.8 days. Although the LUU group had a shorter surgical duration, the difference was not statistically significant. However, intraoperative blood loss, drainage tube removal time, and postoperative hospital stay were significantly reduced in the LUU group, with statistical significance (P<0.05). After surgery, one case of urinary tract infection occurred in each group. Both groups had double-J stents placed postoperatively, which were removed cystoscopically 4-6 weeks later. Preoperative examinations showed no significant differences between the LUU and OUU groups in terms of upper renal pelvis anteroposterior diameter, upper renal ureteral diameter, and upper renal parenchymal thickness. However, in terms of postoperative recovery indicators, the LUU group outperformed the OUU group significantly, including upper renal pelvis anteroposterior diameter, upper renal ureteral diameter, and upper renal parenchymal thickness, with statistical significance (P<0.05). No hydronephrosis or worsening hydronephrosis was observed in the lower kidneys and ureters of the 30 patients postoperatively. Symptoms disappeared in patients with preoperative dribbling, and pain symptoms in the waist and abdomen relieved. No postoperative febrile urinary tract infections were observed. UU is an effective and safe method for treating pediatric completely duplicated kidneys. Compared to open surgery, laparoscopic surgery is associated with less trauma, faster postoperative recovery, and superior postoperative recovery of anatomical parameters (anteroposterior diameter, ureteral diameter, and parenchymal thickness) of the upper kidneys.

Ultrasound-based predictive indicators for treatment outcomes in pediatric vesicoureteral reflux

PurposeTo evaluate the effectiveness of preoperative ultrasound (US) measurements in predicting pediatric vesicoureteral reflux (VUR) treatment outcomes.MethodsThis prospective study enrolled 35 patients (53 renal units) aged 1–16 years who underwent subureteric injection therapy for primary VUR between July 2020 and June 2022. Preoperative ultrasound examinations measured the bladder wall thickness at the ureteral orifice, ureteral submucosal tunnel length, distal ureteral diameter, patient demographics, VUR grade, presenting complaints, bladder–bowel dysfunction, and renal scarring, and the impact of these variables on treatment success was analyzed.ResultsAmong the patients, 91.4% were female, with a mean age of 6.83 ± 3.84 years. A comparison between the treatment success and failure groups revealed no significant differences in the age, sex, VUR grade, laterality, bilaterality, presenting complaints, bladder–bowel dysfunction, bladder wall thickness, or distal ureteral diameter (p > 0.05). However, renal scarring occurred in 16 (38.1%) patients in the treatment success group and 10 (90.9%) in the treatment failure group (p = 0.002). The treatment failure group had shorter detrusor-to-ureteral orifice distances and smaller detrusor-ureteral orifice distance-to-distal ureteral diameter (D/U) ratios than that of the success group (p = 0.004 and p = 0.006, respectively). Patients with a detrusor-to-ureteral orifice distance < 7.4 mm had an 81.82% likelihood of treatment failure.ConclusionUltrasound measurements of the detrusor-to-ureteral orifice distance and D/U ratio proved reliable in predicting the success of endoscopic subureteric injection therapy for VUR.

Quantitative measurement of the ureter on three-dimensional magnetic resonance urography images using deep learning.

Accurate measurement of ureteral diameters plays a pivotal role in diagnosing and monitoring urinary tract obstruction (UTO). While three-dimensional magnetic resonance urography (3D MRU) represents a significant advancement in imaging, the traditional manual methods for assessing ureteral diameters are characterized by labor-intensive procedures and inherent variability. In the realm of medical image analysis, deep learning has led to a paradigm shift, yet the development of a comprehensive automated tool for the precise segmentation and measurement of ureters in MR images is an unaddressed challenge. The ureter was quantitatively measured on 3D MRU images using a deep learning model. A retrospective cohort of 445 3D MRU scans (443 patients, 52±18 years; 217 female patients) was collected and split into training, validation, and internal testing cohorts. A 3D V-Net model was trained for urinary tract segmentation, and a post-processing algorithm was developed for ureteral measurements. The accuracy of the segmentation was evaluated using the Dice similarity coefficient (DSC) and volume intraclass correlation coefficient (ICC), with ground truth segmentations provided by experienced radiologists. The external cohort comprised 50 scans (50 patients, 55±21 years; 30 female patients), and the model-predicted ureteral diameter measurements were compared with manual measurements to assess system performance. The various diameter parameters of ureter among the different measurement methods (ground truth, auto-segmentation with automatic diameter extraction, and manual segmentation with automatic diameter extraction) were assessed with Friedman tests and post hoc Dunn test. The effectiveness of the UTO diagnosis was assessed by receiver operating characteristic (ROC) curves and their respective areas under the curve (AUC) between different methods. In both the internal test and external cohorts, the mean DSC values for bilateral ureters exceeded 0.70. The ICCs for the bilateral ureter volume obtained by comparing the model and manual segmentation were all greater than 0.96 (p < 0.05), except for the right ureter in the internal test cohort, for which the ICC was 0.773 (p < 0.05). The mean DSCs for interobserver and intraobserver reliability were all above 0.97. The maximum diameter of the ureter exhibited no statistically significant differences either in the dilated (p=0.08) or in the non-dilated (p=0.32) ureters across the three measurement methods. The AUCs of ground truth, auto-segmentation with automatic diameter extraction, and manual segmentation with automatic diameter extraction in diagnosing UTO were 0.988 (95% CI: 0.934, 1.000), 0.961 (95% CI: 0.893, 0.991), and 0.979 (95% CI: 0.919, 0.998), respectively. There was no statistical difference between AUCs of the different methods (p>0.05). The proposed deep learning model and post-processing algorithm provide an effective means for the quantitative evaluation of urinary diseases using 3D MRU images.

Ureteral stricture formation after endoscopic removal of obstructing stones: could it be predicted with well-assessed radiological parameters?

The possible role of well-assessed radiological parameters in the prediction of ureteral stricture formation in cases with impacted obstructive ureteral calculi has been evaluated. 46 adult patients with or without ureteral stricture formation after ureteroscopic stone management were included. In addition to stone size and some certain radiological parameters including ureteral wall thickness (UWT) of the involved ureter at the impacted stone site was also measured and noted on computed tomography (CT) images. Parameters were evaluated in two subgroups of cases, namely: Group 1: patients in whom a ureteral stricture formed after endoscopic stone removal and Group 2: patients normal ureteral anatomy without any stricture formation. The possible relationship between the UWT values and degree of hydronephrosis (HN) with subsequent stricture formation was comparatively evaluated. All of the stones were proximal ureteral calculi in both groups. Both the degree of HN and proximal ureteral diameter (PUD) parenchymal was higher in cases with stricture formation. In addition, mean parenchymal thickness was lower and mean values of UWT measurements at the stone site were 3.70 ± 0.97mm and 2.17 ± 0.26mm in Groups 1 and 2, respectively. A cutoff value 2.49mm for UWT was found to be highly predictive for stricture formation. UWT value calculated at the obstructing stone site was found to be predictive enough for the likelihood of ureteral stricture formation with high sensitivity and specificity . This evaluation along with some other radiological parameters may enable the urologists to follow such cases on this aspect with necessary measures taken.

Prediction of spontaneous distal ureteral stone passage using artificial intelligence.

Identifying factors predicting the spontaneous passage of distal ureteral stones and evaluating the effectiveness of artificial intelligence in prediction. The files of patients presenting with distal ureteral stones were retrospectively evaluated. Those who experienced spontaneous passage were assigned to Group P, while those who did not were assigned to Group N. Demographic and clinical data of both groups were compared. Then, logistic regression analysis was performed to determine the factors predicting spontaneous stone passage. Based on these factors, a logistic regression model was prepared, and artificial intelligence algorithms trained on the dataset were compared with this model to evaluate the effectiveness of artificial intelligence in predicting spontaneous stone passage. When comparing stone characteristics and NCCT findings, it was found that the stone size was significantly smaller in Group P (4.9 ± 1.7mm vs. 6.8 ± 1.4mm), while the ureteral diameter was significantly higher in Group P (3.3 ± 0.9mm vs. 3.1 ± 1.1mm) (p < 0.05). Parameters such as stone HU, stone radiopacity, renal pelvis AP diameter, and perirenal stranding were similar between the groups. In multivariate analysis, stone size and alpha-blocker usage were significant factors in predicting spontaneous stone passage. The ROC analysis for the logistic regression model constructed from the significant variables revealed an area under the curve (AUC) of 0.835, with sensitivity of 80.1% and specificity of 68.4%. AI algorithms predicted the spontaneous stone passage up to 92% sensitivity and up to 86% specifity. AI algorithms are high-powered alternatives that can be used in the prediction of spontaneous distal ureteral stone passage.

An evaluation of ureteral diameter ratio and vesicoureteral reflux index in the treatment of primary vesicoureteral reflux

ObjectiveVesicoureteral reflux (VUR) index is a simple, validated tool that reliably predicts significant improvement and spontaneous resolution of primary reflux in children. The aim of this study was to evaluate and compare the ureter diameter ratio (UDR) and VUR index (VURx) of patients treated with endoscopic injection (EI) and ureteroneocystostomy (UNC) methods in the pediatric age group due to primary VUR. MethodsPatients under the age of 18 years old who underwent EI and UNC with the diagnosis of primary VUR between January 2011 and September 2021 were determined as the participants. The UDR was assessed using voiding cystourethrography, and the VURx score was determined prior to treatment based on hospital records included in the study. ResultsA total of 255 patients, 60 (23.5%) boys and 195 (76.5%) girls, with a mean age of 76.5 (range 13.0–204.0) months, were included in the study. EI was applied to 130 (51.0%) patients and UNC was applied to 125 (49.0%) patients due to primary VUR. The optimum cut-off for the distal UDR was obtained as 0.17 with sensitivity and specificity of 73.0% and 63.0%, respectively. The positive and negative predictive values were 66.0% and 70.0%, respectively. ConclusionWhen the UDR and VURx score are evaluated together for the surgical treatment of primary VUR in the pediatric age group, it is thought that it may be useful in predicting the clinical course of the disease and evaluating surgical treatment options.

Development of a new scoring system predicting medical expulsive therapy success on 4-10mm distal ureteral stones: medical expulsive therapy stone score (METSS).

Ureteral stone passage by using medical expulsive therapy (MET) are affected by numerous radiological and clinical parameters. We aimed to construct a scoring system, which would be based on clinical and computed tomography (CT)-derived data, to predict the success of the MET approach. 186 patients presenting to urology clinic or emergency department with unilateral single 4-10mm distal ureteral stone and who had MET were included. All patients were divided into two groups as the MET-successful group and the MET-unsuccessful group. The success rate of MET was 67.2%. Stone size ≥ 6.5mm, stone density > 1078 HU, ureteral wall thickness (UWT) > 2.31mm, ureteral diameter (UD) > 9.24mm, presence of periureteral stranding (PUS) and presence of diabetes mellitus (DM) were stated as the independent risk factors. Based on the regression coefficients on multivariate logistic regression analysis, 1 point for stone size > 6.5mm, 2 points for stone density > 1078 HU, 2 points for UWT > 2.31mm, 3 points for UD > 9.24mm, 1 point for presence of PUS and 1 point for presence of DM were assigned to patients for each risk factor. Higher medical expulsive therapy stone score (METSS) indicated lower MET success. All patients were classified into three risk groups according to METSS: low risk (0-3 points; success percentage: 92.8%); intermediate risk (4-5 points; success percentage: 60.4%) and high risk (6-10 points; success percentage: 8.3%). The METSS seems to separate successfully the patients with a favorable or adverse constellation of factors.

Single-port-plus-one robot-assisted laparoscopic modified Lich-Gregoir direct nipple ureteral extravesical reimplantation in children with a primary obstructive megaureter.

To introduce a new technique of single-port-plus-one robotic laparoscopic-modified Lich-Gregoir direct nipple ureteral extravesical reimplantation and ascertain its validity in the treatment of pediatric primary obstructive megaureter. Between January 2021 and November 2021, we retrospectively analyzed the clinical data of 12 children with primary obstructive megaureter who were admitted to the Department of Pediatric Surgery of Fujian Provincial Hospital. All 12 children were treated with single-port-plus-one robotic laparoscopic Lich-Gregoir direct nipple ureteral extravesical reimplantation. Five of them were female and seven were male, including nine cases were simple obstructive type, while the remaining three cases were obstructive with reflux type. The mean age of the children was 17.33 ± 6.99 (10-36) months and the mean follow-up time was 14.16 ± 1.75 (12-17) months. Changes in preoperative and first-year postoperative parameters were compared. The mean operative time for all 12 children was 123.58 ± 10.85 (110-145) min, with a mean internal operative time of 101.42 ± 0.85 (90-120) min, a mean operative bleeding time of 2.42 ± 0.67 (2-4) ml, and a mean hematuria duration of 16.08 ± 1.44 (14-19) h. The mean indwelling catheterization time was 2.25 ± 0.45 (2-3) days and the mean hospitalization time was 3.83 ± 0.39 (3-4) days. At the postoperative first year, the ureteral diameter, calyceal diameter, and anterior-posterior renal pelvic diameter were found to be significantly smaller than at the preoperative period (18.83 ± 3.21 mm vs. 6.83 ± 1.27 mm, 13.99 ± 3.58 mm vs. 3.5 ± 2.90 mm, and 34.92 ± 4.25 mm vs. 10.08 ± 1.88 mm, P < 0.001). There was a significant increase in renal cortical thickness and the percentage of differential renal function (3.63 ± 1.66 mm vs. 5.67 ± 1.88 mm, 33.75 ± 2.77 mm vs. 37.50 ± 1.31 mm, P < 0.001). The resolution rate of obstruction was 100% and no child developed DeNovo vesicoureteral reflux. The technique of modified Lich-Gregoir direct nipple ureteral extravesical reimplantation can help maintain the physiological direction of the ureter and at the same time enhance the effectiveness of antirefluxing in robotic surgery. The design of a single-port-plus-one wound can produce a cosmetic appearance by concentrating and hiding the wound around the umbilicus. This modified reimplantation procedure has the potential to become a promising technique in the robot-assisted treatment of primary obstructive megaureter.

Challenges of Retrograde Ureteroscopic Procedures in Overweight Patients.

Obesity and urolithiasis are both prevalent conditions that have an impact on the healthcare system. The ureteric diameter and accessibility play a crucial role in the management of urolithiasis in both overweight and normal weight patients. Studies have shown that obesity can lead to changes in ureter diameter where excessive body fat can exert pressure on the kidneys, causing them to enlarge in size and this enlargement can result in a compression of the adjacent structures, including the ureter. The aim of this study is to assess the incidence of intraoperative challenges faced during retrograde ureteroscopic procedures in overweight patients with ureteric and renal calculi. We retrospectively reviewed patients who underwent retrograde ureteroscopic surgery (RURS) for urolithiasis from 1st January 2021 until 30th August 2023. The outcome and any complications were documented and compared with the patient's Body Mass Index (BMI). All patients who undergo RURS in our facility have to have a Non-Contrast CT scan prior to surgery. Procedural success was determined by the ability to obtain access to the stone site intraoperatively and stone-free status in kidney, ureter, and bladder (KUB) X-ray post-operatively. Post-operative complications were recorded up to two weeks post-operatively and classified according to the Calvein Dindo Classification. Our total sample size was 146 patients out of which 75 were overweight and 71 were normal weight patients. In 34 (45%) of overweight patients' access to the ureter was restricted due to a narrow ureteric orifice with ureteroscopy not successful; on the contrary 13 (18%) of normal weight patients faced this same issue. This was statistically significant with a p-value of .004. The stone clearance rates were 91% and 95% in overweight and normal weight patients respectively, which is higher in normal weight patients however this difference was not found to be a statistically significant finding (p-value .028). Overweight patients had 12% Grade I and 8% Grade II complications whereas normal weight patients had 11% Grade I complications and 1.4% Grade II with no higher-grade complications. Retrograde ureteroscopic procedures are a safe treatment modality for patients with urolithiasis in both overweight and normal weight populations. They are shown to have similar success rates between both populations once ureteric access is obtained. However, access failure rates are shown to be slightly higher in overweight patients. Hence, further preoperative patient counselling and technical considerations should be undertaken.

Endoscopic treatment of primary obstructive megaureter with high pressure balloon dilation in infants

Ureteral reimplantation of the dilated ureter in infants is challenging; however, some patients with primary obstructive megaureter (POM) in this age group require intervention due to clinical or radiological progression. We sought to determine if high pressure balloon dilation (HPBD) can serve as a definitive treatment for POM in children under one year of age, or as a temporizing measure until later reimplantation. All patients from a single institution who underwent HPBD between October 2009 and May 2022 were retrospectively reviewed. Patients were excluded if older than 12 months or diagnosed with neurogenic bladder, posterior urethral valves, or obstructed refluxing megaureter. Patients with prior surgical intervention at the ureterovesical junction were excluded. Indications for surgery included progressive hydroureteronephrosis or urinary tract infection (UTI). Balloon dilation was performed via cystoscopy with fluoroscopic guidance, followed by placement of two temporary ureteral stents. Primary outcomes were improvement or resolution of megaureter and rates of subsequent reimplantation. Secondary outcomes included total number of anesthetics and postoperative UTIs. Fifteen infants with median age of 7.6 months (IQR3.8-9.7) underwent HPBD. Twelve (80%) patients were detected prenatally and 3 (20%) aftera UTI. Indication for surgery was progressivehydroureteronephrosis in 10 patients (67%) and UTI in five (33%). All had SFU grade 3 or 4 hydronephrosis on preoperative ultrasound and median distal ureteral diameter was 13mm. Median follow up was 2.9 years. Twelve (80%) succeeded with endoscopic treatment: 7 patients had an undetectable distal ureter on ultrasound at last follow-up, 5 were improved with median distal ureteral diameter of 7mm. Three patients (20%) required ureteral reimplantation due to progressive dilation, all with grade 4 hydronephrosis and distal ureteral diameters were 11, 15, and 21mm. Six patients (40%) required two anesthetics to complete endoscopic treatment. Among those, 4 patients required initial stent placement for passive dilation followed by a second anesthetic for HPBD weeks later. Two patients underwent repeat HPBD following postoperative proximal migration of the ureteral stents. All 15 patients had an additional anesthetic for removal of stents. Five patients (33%) were treated for a symptomatic UTI (4 febrile, 1 afebrile) with the stents indwelling but there were no UTIs in the group following stent removal. Balloon dilation is a practical option for treatment of POM in infants, and in most cases (80%) avoids subsequent open surgery (over median 2.9 years of follow-up).

Does the distal ureteral diameter ratio (UDR) matter in the surgical management of vesicoureteral reflux in children?

To evaluate UDR reliability, sensitivity, specificity and to identify the best treatment basing on UDR among single or double endoscopic injections and ureteral reimplantation. Data of patients affected by primary VUR and treated by endoscopic injection over a 10years period were retrospectively analyzed. Two radiologist attributed reflux grade and UDR on voiding cystourethrogram twice and blinded. Follow-up focused on resolution after 1 or 2 endoscopic injections. Relation between UDR, reflux grade and outcomes were analyzed. Patient enrolled were 198. Low grade VUR was present in 24.8%, grade 3 in 41.6%, grade 4-5 in 33.6%. Resolution after one injection was obtained in 88 patients; among 110 not resolved 104 cases had a second injection. Success after 2 injections was reported in 138 cases. UDR showed a higher reliability compared with reflux grade both in intra than inter-reader measurement (ICC > 90%). Success after 1 or 2 injections was reported for UDR < 0.33 and UDR < 0.47 respectively. UDR shows to be a more reliable measurement that allows for an objective estimation of VUR severity and prognosis. It represents a quantitative parameter that might be useful to identify patients who may benefit endoscopic or surgical treatment, avoiding unnecessary under or over-treatment.