Area of hydronephrosis is a useful predictive factor of impacted ureteral stones.

Ureteroscopic lithotripsy for impacted stones is challenging, but it is important to predict impacted stones preoperatively. Hydronephrosis, which is evaluated by a grading system, is often apparent in impacted stones. However, the currently used grading system is a qualitative evaluation. We, therefore, focused on a quantitative evaluation: the area of hydronephrosis. The aim of this study was to investigate whether the area of hydronephrosis could predict impacted stones more accurately than Society for Fetal Urology grade. We retrospectively identified 160 patients who underwent ureteroscopic lithotripsy for ureteral stones at our hospital between January 2014 and April 2022. Impacted stones were defined as stones fixed to the ureteral wall that could not be moved by means of ureteroscopic manipulation or water pressure. Of the 160 patients, 54 (33.8%) had impacted stones. Comparing patient characteristics, there were significant differences in stone size, ureteral wall thickness, Society for Fetal Urology grade, renal pelvic width and area of hydronephrosis (all P < 0.01). Receiver operating characteristic analysis showed that area of hydronephrosis was the more significant predictive value (area under the curve 0.781) compared with Society for Fetal Urology grade (area under the curve 0.676, P < 0.01). Multivariate analysis revealed that significant independent predictive factors of impacted stones were thicker ureteral wall thickness and larger area of hydronephrosis (both P < 0.01). The area of hydronephrosis and ureteral wall thickness were significant predictors of impacted stones in patients undergoing ureteroscopic lithotripsy for ureteral stones. These factors may be useful for selecting the treatment and preoperative settings.

Primary non-refluxing megaureter: Natural history, follow-up and treatment.

Primary non-refluxing megaureter (PMU) is a congenital dilation of the ureter which is not related to vesicoureteral reflux, duplicated collecting systems, ureterocele, ectopic ureter, or posterior urethral valves and accounts for 5 to 10% of all prenatal hydronephrosis (HN) cases. The etiology is a dysfunction or stenosis of the distal ureter. Most often PMU remains asymptomatic with spontaneous resolution allowing for non-operative management. Nevertheless, in selective cases such as the development of febrile urinary tract infections, worsening of the ureteral dilatation, or reduction in relative renal function, surgery should be considered. CONCLUSION: Ureteral replantation with excision of the dysfunctional ureteral segment and often ureteral tapering is the gold-standard procedure for PMU, although endoscopic treatment has been shown to have a fair success rate in many studies. In this review, we discuss the natural history, follow-up, and treatment of PMU. WHAT IS KNOWN: • PMU is the result of an atonic or stenotic segment of the distal ureter, resulting in congenital dilation of the ureter, and is frequently diagnosed on routine antenatal ultrasound. WHAT IS NEW: • Most often, PMU remains asymptomatic and clinically stable, allowing for non-operative management. • Nevertheless, since symptoms can appear even after years of observation, long-term ultrasound follow-up is recommended, even up to young adulthood, if hydroureteronephrosis persists. • Ureteral replantation is the gold standard in case surgery is needed. In selected cases, however, HPBD could be a reasonable alternative.

Retroperitoneoscopic Simple Nondismembered Pyeloplasty with Da Vinci Si Assistance to Prevent Alignment Shift.

Aims: Retroperitoneoscopic simple nondismembered pyeloplasty (SNDP) with da Vinci Si assistance was developed because of a possible risk for alignment shift after retroperitoneoscopic diamond-shaped bypass pyeloplasty (Diamond-Bypass; DP). Outcomes of SNDP and DP were compared. Materials and Methods: For SNDP, a small longitudinal incision is made on the border of the dilated pelvis and narrowed ureter at the ureteropelvic junction (UPJ). Extending this incision toward the pelvis allows identification of mucosa while maintaining the integrity of surrounding tissues that are so thin and fragile that they will not influence lumen alignment. Data for DP were obtained from a previously published article. Results: For SNDP (n = 3), mean age at surgery was 2.67 years (range: 1-4), mean operative time was 176 minutes. Mean postoperative Society of Fetal Urology (SFU) grades for hydronephrosis were 1.2, 0.7, and 0.6, 1, 2, and 3 months after stent removal, respectively. Postoperative diethylenetriaminepentaacetic acid (DTPA) was normal (n = 3). For DP (n = 5) mean age at surgery was 4.3 years (range: 1-14), mean operative time was 189 minutes. Mean postoperative SFU grades were 2.8, 2.2, and 1.6, respectively. Postoperative DTPA was normal (n = 4) and delayed (n = 1). All SNDP and DP were asymptomatic by 3 months after stent removal. Conclusion: Both SNDP and DP have favorable outcomes. If the UPJ is located at the lowest end of the renal pelvis, SNDP may improve hydronephrosis more quickly.

Intrinsic ureteric obstruction secondary to endometriosis: a rare clinical entity causing obstructive uropathy and renal failure.

Ureteral endometriosis is rare and can be a silent clinical entity, which can potentially lead to serious complications such as obstructive uropathy, sepsis and renal failure. A high clinical suspicion is required especially in childbearing age groups due to non-specific presentation such as renal colic, recurrent urinary tract infection (UTI), renal failure or asymptomatic hydronephrosis.A woman in her 40s presented with febrile UTI and flank pain. She reportedly suffered from recurrent UTIs in the past. Initial workup revealed an infected, obstructed left renal collecting system with gross hydronephrosis and hydroureter to the distal ureter on a significant gynaecological background of severe endometriosis requiring hysterectomy in the past.CT showed chronic obstructive changes and soft tissue nodules within the renal pelvis with no radio-opaque stones. She underwent emergent ureteric stent insertion. Functional imaging demonstrated only 1% contribution of the left kidney with a preserved estimated glomerular filtration rate of 65 mL/min/1.73 m2Endoscopic evaluation of ureters found extensive soft tissue lesions throughout the dilated left collecting system with biopsy-confirmed endometriosis. Subsequently, she underwent laparoscopic nephroureterectomy due to extensive ureteric involvement and chronically obstructed non-functioning kidney. Histopathology demonstrated completely obstructing ureteral endometriosis.Ureteric obstruction secondary to endometriosis can be due to extrinsic or intrinsic disease. In addition to initial assessment with CT urogram MRI may be helpful to evaluate soft tissue thickening. Endoscopic assessment with ureteroscopy and biopsy is required for tissue diagnosis. Surgery is often the treatment of choice, ranging from ureteroureterostomy, ureteroneocystostomy or nephroureterectomy in severe cases.Ureteral endometriosis is a rare clinical entity, clinicians should remain vigilant about common presentations of this rare entity, early diagnosis and prompt treatment is crucial to prevent progression to renal failure.

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 ± 0.97 mm and 2.17 ± 0.26 mm in Groups 1 and 2, respectively. A cutoff value 2.49 mm 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.

Routine Ureteral Stenting in Kidney Transplant Reduces Postoperative Hydronephrosis and Percutaneous Ureteral Interventions: A Single-Center Experience.

OBJECTIVES: The effect of routine ureteral stenting on postoperative hydronephrosis and percutaneous ureteral intervention in kidney transplant remains unknown. This study aimed to evaluate the effects of routine ureteral stenting on hydronephrosis and percutaneous ureteral intervention and the cost benefit of ureteral stenting in kidney transplant. MATERIALS AND METHODS: We retrospectively analyzed patients who underwent kidney transplant at a tertiary institution between 2005 and 2021. We adopted a ureteral stentingprotocol in2017, anda comparisonwas performed with previous patients without stents. RESULTS: In total, 539 patients underwent kidney transplant(271 with stents [51.3%], 268 without stents [49.7%]). Hydronephrosis was detected in 16 cases (5.9%) and 30 cases (11.2%) of groups with and without stents,respectively (P = .041). Among patients with hydronephrosis, the number of patients who underwent percutaneous ureteral intervention was significantly lower in the stent group than in the nostent group (1 [6.25%] vs 10 [33.33%]; P= .014).Twenty patients (3.71%) experienced major urologic complications (19 [7.1%] in the no-stent group, and 1 [0.4%] in the stent group; P = .001). No significant differences between the groups were shown in the incidence of urinary tract infections within 3 months of transplant (24 [8.9%] vs 22 [8.2%]; P = .846). No differences were shown between the groups in ureterovesical anastomosis time (24.4 vs 24.03 min; P = .699) or 1-year graft survival (97% vs 97.8%; P = .803). The healthcare cost was significantly lower in the stent group than in the no-stent group by $1702.05 ($15000.89 vs $16702.95; P < .001). CONCLUSIONS: Routine ureteral stenting in kidney transplant significantly decreased the incidence of postoperative hydronephrosis and percutaneous ureteral intervention. Stenting did notlead to increased urinary tract infections and was cost-effective.

Pelvic squamous cell carcinoma of unknown primary origin with hydronephrosis and ureteral stricture: A case report.

BACKGROUND: Cancer of unknown primary (CUP) is a very challenging disease, accounting for 2% to 9% of all new cancer cases. This type of tumor is a heterogeneous tumor whose primary site cannot be determined by standard examination. It has the characteristics of early metastasis, strong aggressiveness, and unpredictable mode of metastasis. Studies have shown that there is no consensus on the treatment of CUP and that there is a wide range of individual differences. In most cases, surgical removal of tumor is the most typical treatment for pelvic tumors. Herein, we report a case of a large pelvic tumor of unknown origin that had compressed the sigmoid colon and ureter and was completely removed by surgery. Postoperative diagnosis was pelvic metastatic squamous cell carcinoma. CASE SUMMARY: A 68-year-old man with pelvic tumor who initially complained of recurrent low back pain and painful urination. The mass was initially diagnosed as a pelvic tumor of unknown origin. The patient underwent complete resection of the tumor by laparotomy. The tumor was pathologically diagnosed as squamous cell carcinoma. CONCLUSION: Based on the treatment experience of this case, surgery alone cannot improve the poor prognosis of CUP. Since chemotherapy and immunotherapy have achieved promising efficacy in various cancers, and immunotherapy has the characteristics of low side effects and good tolerability, we recommend that patients with CUP should receive chemotherapy and/or immunotherapy for better survival outcomes.

Voiding Cystourethrogram Before Pyeloplasty: To Do or Not To Do?

OBJECTIVE: To assess the incidence of concomitant vesicoureteral reflux (VUR) in unilateral cases of ureteropelvic junction obstruction (UPJO) and to identify factors that predict VUR. METHODS: Files of 381 pediatric patients who underwent unilateral pyeloplasty between 2000 and 2017 were retrospectively reviewed. A total of 270 patients with available data and ≥5 years of follow-up were eligible for this study. Demographic parameters, preoperative hydronephrosis grade, renal pelvis anteroposterior diameter (APD), renal parenchymal thickness (PT), split renal functions on MAG-3 scan and VUR status were noted. The patients were divided into two groups: those with concomitant VUR (group I, n: 24, 8.9%) and those without VUR (group II, n: 246, 91.1%). RESULTS: Among 270 patients (205 boys, 75.9%) with a median age of 4 months (2-98), 197 (72.9%) had antenatal hydronephrosis. Median follow-up was 11 years (5-22). Among 24 patients with concurrent VUR, 6 (25%) had grade II VUR, whereas grade III-V VUR was detected in 18 (75%). Of these, 12 (50%) had ipsilateral VUR, 3 (12.5%) had contralateral, and 9 (37.5%) had bilateral VUR. In a median 137-month follow-up, spontaneous VUR resolution was observed in 6 (25%) patients, whereas 15 (62.5%) patients underwent endoscopic subureteral injection and 3 (12.5%) patients ureteroneocystostomy, respectively. Preoperative APD [35.5, (Inter Quantile Range) IQR (27.6-36.0) vs 26.5 IQR (25.0-35.0), P = .004] were significantly higher in group I, whereas group I had significantly lower PT [3.7, IQR (3.4-6.4) vs 5.8 IQR (4.4-6.1), P = .026]. Predictive factors for concomitant VUR were presentation with febrile UTI (odds ratio (OR): 2.769, P = .048), PT <3.95 mm (OR: 1.367, P = .043), and APD >28.8 mm (OR: 1.035, P = .001). CONCLUSION: Our results indicated that concomitant VUR and UPJO might be detected in 1 out of every 11 patients undergoing pyeloplasty, while some type of surgical intervention for VUR was required in 75% of these patients. Thus, voiding cystourethrogram prior to pyeloplasty may be limited in those presenting with febrile urinary tract infection, having higher APD and lower PT on preoperative urinary ultrasonography.

Application of ultrasound-guided percutaneous nephrostomy in the treatment of a solitary kidney with hydronephrosis due to renal tuberculosis.

PURPOSE: To investigate the value of ultrasound-guided percutaneous nephrostomy and nephrostomy tube replacement for treating a solitary kidney with hydronephrosis due to renal tuberculosis. METHODS: Clinical data of patients with a solitary kidney with hydronephrosis caused by renal tuberculosis who underwent ultrasound-guided percutaneous nephrostomy in our hospital from January 2011 to December 2022 were retrospectively analyzed. The associated success rate and complications were statistically analyzed, pre- and post-catheterization changes in serum creatinine and blood urea nitrogen levels were compared, success rate and complications of nephrostomy tube replacement in patients with long-term catheterization were statistically analyzed, and the impact of long-term catheterization on patient life was investigated. RESULTS: Overall, 32 patients aged 17-75 years (average age: 44.1 ± 16.9 years) underwent ultrasound-guided percutaneous nephrostomy. Sixty-three punctures were performed; the puncture success rate was 100%. The levels of serum creatinine and blood urea nitrogen of patients decreased after catheterization, and the differences between the pre-catheterization and post-catheterization were significant (P < 0.05). There were 1, 3, and 12 cases of serious, minor, and fistula-related complications, respectively. The mean duration of the indwelling catheter was 56.7 ± 36.2 (range, 13-120) months. The number of nephrostomy tube replacements was 344 times, and the success rate was 100%. All patients could take care of the puncture point by themselves. CONCLUSION: Ultrasound-guided percutaneous nephrostomy and nephrostomy tube replacement have a high success rate and few complications, which can improve the renal function of patients. It is of great value for treating a solitary kidney with hydronephrosis caused by renal tuberculosis.

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

INTRODUCTION AND OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULTS: Fifteen infants with median age of 7.6 months (IQR 3.8-9.7) underwent HPBD. Twelve (80%) patients were detected prenatally and 3 (20%) after a UTI. Indication for surgery was progressive hydroureteronephrosis 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 13 mm. 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 7 mm. Three patients (20%) required ureteral reimplantation due to progressive dilation, all with grade 4 hydronephrosis and distal ureteral diameters were 11, 15, and 21 mm. 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. CONCLUSION: 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).

Laparoscopic assisted dismembered pyeloplasty versus open pyeloplasty in UPJO with poorly function kidney in pediatrics.

BACKGROUND: The management of UPJO with poor function kidney, less than 10%, has been the subject of debate for more than a decade. Some authors have recommended nephrectomy, while others favor renal salvage (pyeloplasty). We report our experience with laparoscopic assisted pyeloplasty in pediatric patients with poorly functioning kidneys in comparison with an open approach. MATERIALS AND METHODS: A retrospective study was conducted to review 65 patients who were diagnosed with hydronephrosis and had impaired renal function due to UPJO. The study was conducted in the pediatric surgery departments of Al-Azhar University Hospital and Fattouma Bourguiba University Hospital of Monastir over a period of 20 years. Limited to pediatric patients with UPJO with ≥ Grade III hydronephrosis, antero-posterior pelvic diameter ≥ 20 mm, as well as a renal function equal to or less than 10%, was corrected by laparoscopic assisted or open pyeloplasty. RESULTS: There were 40 cases in group A who underwent laparoscopic assisted pyeloplasty, and 25 cases in group B who underwent open pyeloplasty. There were no complications or difficulties during the operation. The mean operative time in group A was 90 ± 12 min, while in group B, it was 120 ± 11 min. The renal assessment parameters significantly improved in both groups. In group A, the mean split renal function was 7.9 ± 1.3% and increased to 22.2 ± 6.3%. In group B, the mean split renal function was 8.1 ± 1.1% and increased to 24.2 ± 5.1%. However, the differences between both groups in terms of pre-operative and post-operative renal functions were statistically insignificant. CONCLUSION: Laparoscopic assisted pyeloplasty is an effective treatment for patients with poorly functioning kidneys, especially those with less than 10% function. While this surgical procedure requires shorter operative times, it yields functional outcomes that are comparable to open approach.

Risk factors for adverse outcomes after pediatric pyeloplasty: A retrospective cohort study.

PURPOSE: To identify the risk factors for adverse outcomes after pediatric pyeloplasty. METHODS: We conducted a retrospective review of all children under the age of 14 years who underwent primary pyeloplasty for unilateral ureteropelvic junction (UPJ) obstruction at a single teaching hospital in Tunisia between January 1, 2013, and December 31, 2022. RESULTS: A total of 103 patients were included. Median age of patients at surgery was 27 months (interquartile range [IQR], 13-44). On ultrasound, median renal pelvic anteroposterior diameter was 3.2 cm (IQR, 2.3-4), and the median renal cortex thickness (RCT) was 2.5 mm (IQR, 2-3.5). Median differential renal function (DRF) on preoperative radionuclide renal scan was 40% (IQR, 30-46). Postoperative adverse outcomes occurred in 28 patients (27.2%). These included 19 cases of urinary tract infections (UTIs), 11 cases of UPJ restenosis, four cases of UPJ leakage, two cases of urinoma, and two cases of diversion-related complications. Multivariate logistic regression analysis revealed two factors significantly and independently related to postoperative negative outcomes: RCT <3 mm and DRF > 50%. CONCLUSION: Our study demonstrated that preoperative RCT on ultrasound of less than 3 mm and preoperative DRF on radionuclide renal scan of more than 50% were independent risk factors for adverse outcomes following pediatric pyeloplasty. These factors could be of interest in identifying, early on, patients who will develop postoperative negative outcomes, giving them more attention and support, and explaining the prognosis to the patient and family.

Ureteropelvic junction obstruction with polyps in children: clinical manifestations and supranormal preoperative differential renal function.

OBJECTIVE: To describe and analyze the clinical manifestation and pre-DRF of UPJO children with polyps and explore the possible influencing factors of supranormal pre-DRF. PATIENTS AND METHODS: All patients undergoing primary Anderson-Hynes pyeloplasty for UPJO due to polyp were retrospectively reviewed. Patients' characteristics, parameters of ultrasound and dynamic renograms (DR) were recorded in elaborate. Pre-DRF in groups of different age, weight, gender, pain, grade of hydronephrosis, anterio-posterior pelvic diameter (APD), length of kidney and postoperative ultrasonic parameters were compared. RESULTS: A total of 18 UPJO children with polyps were included. Five (27.78%) patients had SFU III grade of hydronephrosis. Seven (38.89%) patients were supranormal pre-DRF. All patients had pre-DRF > 40%. Drainage curve was delayed excretion in 12 (66.67%) patients and T1/2 < 20 min was in 4 (22.22%) patients. Among the 16 patients who underwent preoperative IVP examination, 15 (93.75%) patients had concentration of intrarenal pelvis contrast agent within 10 min. No significant difference in post-APD reduction rate and post-minPT increased was found between supranormal pre-DRF and non-supranormal pre-DRF groups. The supranormal pre-DRF was more likely to occur in young and low-weight children. CONCLUSION: The preoperative renal function of UPJO patients with polyps was well preserved, and 38.89% of them had supranormal pre-DRF. Patients with supranormal pre-DRF can be managed with the same strategies as those with normal renal function.

Analysis of the Efficacy of Elastography in Comparison with Dynamic Renal Nuclear Scintigraphy in the Evaluation of Unilateral Pelvi-Ureteric Junction Obstruction.

INTRODUCTION: In hydronephrosis due to pelviureteric junction obstruction (PUJO), an obstruction to urine flow may lead to increased pelvic pressure, which may cause interstitial fibrosis and renal impairment. Recently, there have been reports on renal pelvic assessment using ultrasound elastography (USE). This study was conducted to see if USE can evaluate PUJO and if it can be correlated to the findings of the dynamic renal nuclear scan. MATERIAL AND METHODS: In this observational study, only patients with unilateral PUJO underwent acoustic radiation force impulse (ARFI) elastography. A rectangular region of interest (ROI) measuring 5 × 10 mm was positioned on the cortex region of the upper, mid, and lower poles of the affected kidney. Three valid measurements were obtained, from which a mean value was calculated. A dynamic renal nuclear scan using Technetium-99m ethylene dicysteine (EC or TC99 m EC) was obtained and split renal function (SRF) was used for comparison. RESULTS: In the group of 20 patients, the mean age was 3.37 years. The mean SRF of the affected kidney was 26.65 %, and the corresponding USE value was 0.45 kpa. The Spearman's rho correlation coefficient for SRF and USE was 1 and 0.672, respectively (p = 0.001). Elastography was not feasible if SRF was less than 20 %. CONCLUSION: USE may be able to comment on the renal functional status of hydronephrosis. If USE is reported as non-feasible, it may suggest that renal function is grossly compromised. It may serve as an alternative diagnostic modality for renal functional evaluation. LEVEL OF EVIDENCE: Level II, Prospective Cohort Study.

Bladder metastasis from inflammatory breast cancer presenting with hematuria and hydronephrosis.

We report a rare case of a 56-year-old Ukrainian female with inflammatory breast cancer (IBC) who underwent neoadjuvant chemoradiation and left radical mastectomy with her clinical course complicated by disease recurrence with bone and bladder metastases 2.5 years after her initial diagnosis. We highlight the presentation and diagnosis of genitourinary involvement of metastatic IBC, which has not previously been described in the literature.

Pilot study of machine learning in the task of distinguishing high and low-grade pediatric hydronephrosis on ultrasound.

PURPOSE: Hydronephrosis is a common pediatric urological condition, characterized by dilation of the renal collecting system. Accurate identification of the severity of hydronephrosis is crucial in clinical management, as high-grade hydronephrosis can cause significant damage to the kidney. In this pilot study, we demonstrate the feasibility of machine learning in differentiating between high and low-grade hydronephrosis in pediatric patients. MATERIALS AND METHODS: We retrospectively reviewed 592 images from 90 unique patients ages 0-8 years diagnosed with hydronephrosis at the University of Chicago's Pediatric Urology Clinic. The study included 74 high-grade hydronephrosis (145 images) and 227 low-grade hydronephrosis (447 images). Patients were excluded if they had less than 2 studies prior to surgical intervention or had structural abnormalities. We developed a radiomic-based artificial intelligence algorithm incorporating computerized texture analysis and machine learning (support-vector machine) to yield a predictor of hydronephrosis grade. RESULTS: Receiver operating characteristic analysis of the classifier output yielded an area under the curve value of 0.86 (95% CI 0.81-0.92) in the task of distinguishing between low and high-grade hydronephrosis using a five-fold cross-validation by kidney. In addition, a Mann-Kendall trend test between computer output and clinical hydronephrosis grade yielded a statistically significant upward trend (p<0.001). CONCLUSIONS: Our findings demonstrate the potential of machine learning in the differentiation between low and high-grade hydronephrosis. Further studies are warranted to validate our findings and their generalizability for use in clinical practice as a means to predict clinical outcomes and the resolution of hydronephrosis.

Congenital lower urinary tract obstruction with spontaneous fetal bladder rupture due to posterior urethral valves: a case report.

BACKGROUND: Congenital lower urinary tract obstruction (LUTO) is a rare but significant condition affecting fetal urinary tract development. LUTO has a range of etiologies, with posterior urethral valves (PUV) being the most common cause. The prenatal diagnosis of LUTO plays a crucial role in recognizing the condition and guiding management decisions. Prenatal ultrasound serves as the primary tool for identifying LUTO, with key findings including megacystis, bladder wall thickening, oligohydramnios, hydronephrosis, and the 'keyhole sign' indicating dilatation of the posterior urethra. We present a case of congenital LUTO with a rare complication of spontaneous fetal bladder rupture and urinary ascites, treated by peritoneo-amniotic shunt placement. CASE PRESENTATION: A 27-year-old pregnant Caucasian women was referred at 28 weeks of pregnancy due to the presence of megacystis and bilateral hydronephrosis on routine ultrasound and suspicion of LUTO. Repeat ultrasound at 29 weeks showed significant fetal ascites, oligohydramnios and resolution of megacystis and hydronephrosis, after which diagnosis of spontaneous bladder rupture was made. Despite ascites aspiration and amnio-infusion, there was persistent ascites and oligohydramnios. A peritoneo-amniotic shunt was placed with resolution of ascites and normalization of the amniotic fluid volume. At 35 weeks, relapse of the megacystis was observed with bilateral pyelectasis and oligohydramnios, possibly due to healing of the bladder rupture, after which elective cesarean section was planned. Cystography confirmed spontaneous healing of the bladder rupture and the presence of posterior urethral valves, which were resected in the neonatal period with cold knife incision. Total follow-up of 8 years continued to show positive ultrasonographic results and good renal function, but the child suffers from bladder dysfunction, manifesting as overactive bladder disease. CONCLUSIONS: LUTO might lead to important renal dysfunction and pulmonary hypoplasia in case of increasing disease severity. Spontaneous bladder rupture might improve renal prognosis, acting as a pop-off mechanism by decompression of the urinary tract. However, fetal bladder rupture is rare and only few cases have been reported. Prenatal intervention can be considered for moderate or severe LUTO, but the benefit for long-term outcome remains uncertain and further studies are needed.

[A Study of Retrograde Ureteroscopic Lithotripsy with Ureteral Access Sheath for Urinary Calculus After Ileal Conduit Construction].

We retrospectively evaluated the safety and effectiveness of retrograde ureteroscopy via ileal conduit construction. Between January 2014 and December 2021, 5 patients (8 procedures) with ileal conduit construction received retrograde ureteroscopic lithotripsy with a 11/13 Fr ureteral access sheath. At postoperative 1 month, a plain computed tomography (CT) and kidney, ureter, and bladder X-ray (KUB) were performed to assess stone fragmentation and hydronephrosis. According to postoperative imaging, stone-free was defined as residual fragments of 4 mm or less on KUB and 2 mm or less on CT. The mean stone size was 11 mm (6-13 mm). The mean stone volume was 1. 51 ml (0.33-2.56 ml). The mean operative time was 91 min (60-133 min). SFR was 100% on KUB and 87.5% on CT. One procedure (12.5%) resulted in a postoperative fever greater than 38.5℃. There were no complications of grade III or higher according to the modified Clavien-Dindo classification. No exacerbation of hydronephrosis was observed on CT. Retrograde ureteroscopy with a ureteral access sheath was found to be effective for urolithiasis in patients with ileal conduit.