Ureteropelvic Junction Obstruction Research Articles

The use of urinary osmolality to evaluate postoperative renal function in children with ureteropelvic junction obstruction

Split renal function measured in a diuretic renogram is the most popular tool in initial assessment and follow-up of patients with ureteropelvic junction obstruction (UPJO). This study aims to evaluate the use of maximum urinary osmolality after desmopressin administration (DDAVP) to detect renal dysfunction. 56 children (33 males, 23 females) diagnosed with UPJO underwent quantification of the maximum urinary osmolality (UOsm) at diagnosis. 41 of these children (28 males, 13 females) underwent surgery for UPJO and quantification of the UOsm before and after the surgical intervention (six to 18 months postoperatively) and were included in this longitudinal study. At diagnosis, UOsm measured after desmopressin administration was abnormal in 64% of patients. After surgical intervention, this rate decreased to 53%. At initial assessment, high creatinine levels were found in 32% of infants younger than one year of age. Albumin/Cr and NAG/Cr ratios were elevated in 12% and 7% of cases, respectively. After surgical intervention, an improvement in the NAG/creatinine ratio and creatinine levels was observed. Preoperative split renal function of the affected kidney was less than 45% in 39% of cases, normal in 44%, and greater than 55% in 17%; in these three subgroups, no differences in renal function markers were found. The most sensitive parameter to detect alterations in renal function in children with UPJO is the UOsm and, therefore, the most useful in the follow-up after surgery. No correlation was found between other functional and morphological parameters obtained on renal ultrasound and renogram.

P1074 - Treatment of ureteropelvic junction obstruction and urolithiasis in children with minimally invasive surgery

P1074 - Treatment of ureteropelvic junction obstruction and urolithiasis in children with minimally invasive surgery

Urine neutrophil gelatinase-associated lipocalin (NGAL) measurement is not predictive for ureteral patency in pediatric patients following pyeloplasty: a pilot study

Objective: To evaluate the benefit of urine neutrophil gelatinase-associated lipocalin (NGAL) measurement to predict the ureteral patency in pediatric patients undergoing pyeloplasty. Materials and Methods: Ureteropelvic junction obstruction patients who underwent unilateral dismembered pyeloplasty had urine NGAL measurements taken intraoperatively during pyeloplasty and postoperatively at six months following surgery. All patients were evaluated preoperatively and postoperatively with renal scans. Pairwise comparisons and correlation analyses were performed to determine the dynamics and benefits of urine NGAL measurement. Results: Thirteen patients were included in this pilot study with a mean age of 3.2 years at surgery. Mean intraoperative bladder urine level was 4.43 ng/mL, and median intraoperative renal pelvic urine NGAL level was 3.70 ng/mL. There was no significant difference between these two levels (p-value = 0.76). Six months after pyeloplasty, 9/13 patients demonstrated significant reduction in the bladder urine NGAL level (at least 50% reduction), and 5/13 patients showed ureteral patency based on postoperative renal scan (more than 5% improvement in differential renal function or the conversion of diuretic half time. However, the finding of significant reduction of urine NGAL level did not correlate with ureteral patency (r = -0.50, p-value = 0.08). Conclusion: Although bladder urine NGAL level reduces in most pediatric patients following pyeloplasty, this decline is not reflective of the finding of ureteral patency from renal scanning. The benefits of urine NGAL measurement in this context remain unclear and require further large-scale investigation.

Predicting the likelihood of prolongation of half-time among infants with initially indeterminate drainage values: A single-institution retrospective study of 535 patients with ureteropelvic junction obstruction

Prior studies have shown a broad half time (T1/2) interval on MAG3 diuresis renography (DR) that is indeterminate for obstruction. We aimed to refine and sub-divide the indeterminate range and associate it with clinically meaningful outcomes: pyeloplasty and pyeloplasty-free survival. We identified patients <1.5 years-old at presentation with unilateral, isolated moderate to severe hydronephrosis who underwent DR from 2000 to 2016. A logistic regression model was created using T1/2 to predict surgery. An indeterminate range was defined based on patients with <90% probability of pyeloplasty or resolution. This group was sub-divided into three T1/2 intervals: 5-20, 21-40, and 41-60min. Endpoints were pyeloplasty and pyeloplasty free survival. Indications for surgery were loss of differential renal function (DRF), worsening T1/2, family preference, and/or pain. Among 2025 patients with DR, 704 met criteria (169 were lost to follow up). Of the remaining 535, 218 had pyeloplasties and 317 did not. The Pyeloplasty group had significantly worse DRF, T1/2at initial DR, and exited the study earlier, at a median age 1.1years vs 2.3 years (p<0.001). For all patients with antenatally detected unilateral UPJ obstruction, the odds of undergoing pyeloplasty at any time increased by 1.8 times (p<0.001 [95% CI: 1.04, 1.08]) per 10 unit increase in T1/2 until T1/2=60. However, in patients with intermediate drainage, five year surgery-free survival probability for patients with T1/2 5-20, 21-40, and 41-60min were 79.7%, 46.7% and 33.3% respectively (χ2=41.2, P = <0.001). Previous efforts to define indeterminate drainage resulted in ranges for T1/2 that were too broad to be clinically useful. Within our endpoint-defined indeterminate range, our data show that there are significant step offs in 5-year surgery-free survival for patients with T1/2<20min, 21-40min, and 41-60min. Although there is a steady decrease in surgery-free survival among patients with a T1/2 of 21-40min over the first 5 years of life, half can be managed nonoperatively. These patients likely represent the true intermediate risk group and closer follow up is justified. Initial T1/2 on DR is predictive of future surgery. When drainage is "indeterminate" for obstruction, sub-stratification allows for more accurate prognostication.

Surgical treatment of patients with strictures of the ureteropelvic junction: historical aspects

The review article is devoted to the history of surgical treatment of the ureteropelvic junction obstruction. The data on the main stages of development and improvement of the operative technique are presented, the main methods of restoring the outflow of urine from the kidney with strictures of the ureteropelvic junction are described. The analysis of modern methods of surgical treatment of this category of patients has been carried out.

The Course of Congenital Hydronephrosis in Infancy

Objective: The aim of our study is to examine the spontaneous resolution rates of congenital hydronephrosis from a recent perspective. Material and Methods: Sixty-nine pediatric patients (M/F=46/23) with congenital hydronephrosis were enrolled in this study. Results: The mean age at the first postnatal examination was 10.8±7.6 days, and the mean age at the time of the final examination was 9.5±3.2 months. Forty-eight patients’ renal anteroposterior diameters (APD) (69.5%) improved while 8 (11.6%) patients’ APDs worsened during the follow-up period. However, MAG3 of these 8 patients was normal. The remaining thirteen (18.9%) patients had congenital anomalies of the kidney and the urinary tract (8 vesicoureteral reflux, 5 cases of ureteropelvic junction obstruction). The mean baseline APD was 9.1±2.8 mm in the group with reduced APD, and 9.7±2.8 mm in the one with increased APD (p=0.461). The mean APD at the final visit was significantly lower in the group with reduced APD than that in the group with increased APD (5.1±1.8 mm vs 17.9±12.6 mm; p=0.001). The anteroposterior diameter of 26 (81.25%) patients with left-sided hydronephrosis and 10 (71.4%) patients with right-sided hydronephrosis regressed spontaneously. The rate of spontaneous resolution was relatively low in patients with bilateral hydronephrosis (n=13; 56.5%) compared to unilateral ones. Conclusion: Our study indicates that an initially mild hydronephrosis does not exclude a pathological course in cases of congenital hyronephrosis. Therefore, in such patients, routine ultrasonography should be done regularly.

Renal functional improvement after pediatric pyeloplasty in kidneys with split renal function less than 20%: a single institute experience

BackgroundPediatric pyeloplasty in ureteropelvic junction obstruction (UPJO) is indicated in renal impaired drainage or renal function deterioration. The improvement of renal function after pediatric pyeloplasty is still controversial in poorly functioning kidneys. Past studies on poorly functioning kidneys had a variable SRF specification, and these studies often had a limited number of patients so that they did not achieve statistical significance. The study aims to detect the renal functional improvement after pediatric Anderson-Hynes pyeloplasty (AHP) with split renal function (SRF) less than 20% (poor renal function).ResultsA retrospective study included 46 pediatric patients with unilateral UPJO who underwent open AHP with SRF < 20% on a renal isotope scan from August 2012 to October 2018. Success was defined based on either improvement in symptoms, improvement in drainage on postoperative renography, and/or improvement or stability in SRF on the renal scan done 6 months postoperatively and yearly thereafter. Deterioration of SRF by more than 5% was deemed to be deterioration. An increase in SRF of more than 5% was deemed to be an improvement.A total of 46 patients with a mean age of 32 months with poor renal function on isotope renogram (SRF < 20%) were included. All patients had an obstructive pattern on the preoperative radionuclide scans. The median preoperative SRF was 9.26%. The mean (range) follow-up was 30 months. The success rate was 91.3%. Three patients underwent redo pyeloplasty, whereas a secondary nephrectomy was necessary for one. The remaining (42) patients showed stability or improvement of SRF with no further symptoms. Renal scintigraphy at 6 and 12 months after surgery revealed significantly increased SRF compared to preoperative one.ConclusionPoorly functioning renal unit with SRF < 20% can show functional improvement and recoverability after pediatric pyeloplasty.

Predictive factors for early discharge (≤24 hours) and re-admission following robotic-assisted laparoscopic pyeloplasty in children.

Minimally invasive pyeloplasty (MIP) for correction of ureteropelvic junction obstruction in children has significantly improved the postoperative management of these patients. In this study, we sought to examine the factors associated with early discharge (≤24 hours) in children who underwent robotic-assisted laparoscopic pyeloplasty (RALP). We performed a retrospective chart review of all children who underwent RALP from 2012-2018 in our center. Descriptive statistics and a non-adjusted risk analysis were performed to evaluate the factors associated with early discharge (≤24h), re-admission, and complications within the first 30 days after the procedure. Eighty-nine patients out of 124 total pyeloplasties (72%) stayed ≤24 hours post-surgery. Of the variables analyzed, later cases were statistically associated with length of stay (LOS); the first 55 patients had a lower probability of being hospitalized for ≤24 hours (odds ratio [OR] 0.24, 95% confidence interval [CI] 0.09-0.64, p=0.004). RALP for children is associated with a high rate of early recovery, short hospital stay, and low re-admission and complication rates. Although not statistically significant, patients with shorter operative room time also had a shorter LOS. An increased LOS was observed in the initial patients of our series, and this is most likely explained by the initial learning curve of the team for the procedure itself and the more conservative postoperative management.

Crossing vessels with suspension versus transposition in laparoscopic pyeloplasty of patients with ureteropelvic junction obstruction: a retrospective study

PurposeTo compare the effects of two different methods of laparoscopic pyeloplasty for the treatment of crossing vessels.MethodsFrom January 2016 to August 2019, 33 patients with ureteropelvic junction obstruction (UPJO) underwent laparoscopic pyeloplasty at our center, including 21 men and 12 women, ranging from 14 to 66 years of age. There were 20 and 13 cases on the left and right sides, respectively. Patients underwent laparoscopic pyeloplasty (Anderson-Hynes operation). During the operation, either a Hem-o-lok clip suspension or transposition was used to treat the crossing vessels. The double-J stent was removed 8 weeks after the operation. The clinical data of patients were collected and follow-ups were regularly performed after the operation.ResultsAll the crossing vessels were successfully preserved, and none of them were severed during the operation. The average operation time was 210.6 ± 58.9 min in this group and the average time to manage the crossing vessel was 8.0 ± 3.5 min, 5.9 ± 1.4 min in the suspension group, and 11.7 ± 3.0 min in the transposition group. The dilation of the affected side was 4.8 ± 1.5 cm before operation and 1.2 ± 1.3 cm 3 months after operation. The difference was statistically significant (P < 0.05). Follow-up to February 2020 showed no significant changes in the kidney size in all patients and hydronephrosis was relieved.ConclusionFor UPJO patients with crossing vessel compression, the method of Hem-o-lok suspension or vascular transposition can be used to relieve crossing vascular compression and improve the success of pyeloplasty.

Treatment of infants with ureteropelvic junction obstruction: findings from the PURSUIT network.

Studies based on administrative databases show that infant pyeloplasty is associated with minority race/ethnicity but lack clinical data that may influence treatment. Our objective was to identify clinical and demographic factors associated with pyeloplasty in infants from three large tertiary centers. We reviewed infants with unilateral Society for Fetal Urology (SFU) grade 3-4 hydronephrosis seen at three tertiary centers from 2/1/2018 to 9/30/2019. Patients were excluded if > 6months old or treated surgically prior to the initial visit. Outcomes were: pyeloplasty < age 1year and SFU grade on most recent ultrasound (US) within the first year. Covariables included: age at the initial visit, race/ethnicity, treating site, insurance type, febrile UTI, and initial imaging findings. Univariable and multivariable analyses were performed using log-rank tests and Cox proportional hazards models, respectively. 197 patients met study criteria; 19.3% underwent pyeloplasty. Pyeloplasty was associated with: treating site (p = 0.03), SFU 4 on initial US (p = 0.001), MAG-3 (p < 0.001), and T½ > 20min (p < 0.001) in patients undergoing a MAG-3 (n = 107). MAG-3 (p < 0.001) and location (p = 0.08) were associated with earlier time to pyeloplasty on multivariable Cox analysis. In infants with follow-up US (n = 115), initial SFU grade, MAG-3 evaluation or findings, and pyeloplasty were not associated with improvement of hydronephrosis. We found that infant pyeloplasty rates vary between sites. Prolonged T½ was associated with surgery despite prior studies suggesting this is a poor predictor of worsening dilation or function. These findings suggest the need to standardize evaluation and indications for intervention in infants with suspected UPJ obstruction.

CDH12 as a Candidate Gene for Kidney Injury in Posterior Urethral Valve Cases: A Genome-wide Association Study Among Patients with Obstructive Uropathies

BackgroundPosterior urethral valves (PUVs) and ureteropelvic junction obstruction (UPJO) are congenital obstructive uropathies that may impair kidney development. ObjectiveTo identify genetic variants associated with kidney injury in patients with obstructive uropathy. Design, setting, and participantsWe included 487 patients born in 1981 or later who underwent pyeloplasty or valve resection before 18 yr of age in the discovery phase, 102 PUV patients in a first replication phase, and 102 in a second replication phase. Outcome measurements and statistical analysisSigns of kidney injury were defined as dialysis, nephrectomy, kidney transplantation, estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2, high blood pressure, antihypertensive medication use, proteinuria, and/or one kidney functioning at <45%. We used χ2 tests to calculate p values and odds ratios for >600 000 single-nucleotide polymorphisms (SNPs) in the discovery sample comparing patients with and without signs of kidney injury within 5 yr after surgery. We performed stratified analyses for PUV and UPJO and Kaplan-Meier and Cox regression analyses in the discovery and two replication samples for the associated SNPs, and RNA and protein expression analyses for the associated gene in fetal tissues. Results and limitationsDespite the small and nonhomogeneous sample, we observed suggestive associations for six SNPs in three loci, of which rs6874819 in the CDH12 gene was the most clear (p = 7.5 × 10–7). This SNP also seemed to be associated with time to kidney injury in the PUV discovery and replication samples. RNA expression analyses showed clear CDH12 expression in fetal kidneys, which was confirmed by protein immunolocalization. ConclusionsThis study identified CDH12 as a candidate gene for kidney injury in PUV. Patient summaryWe found that variants of the CDH12 gene increase the risk of kidney injury in patients with extra flaps of tissue in the urethra (posterior urethral valves). This is the first report on this gene in this context. Our study provides interesting new information about the pathways involved and important leads for further research for this condition.

Robot-assisted pyeloplasty using a new robotic system, the KangDuo-Surgical Robot-01: a prospective, single-centre, single-arm clinical study.

Open Anderson-Hynes dismembered pyeloplasty was the criterion standard for ureteropelvic junction obstruction. Laparoscopic pyeloplasty was comparable to open pyeloplasty in success rates while laparoscopic pyeloplasty offered the advantages of decreased morbidity, shorter hospital stay, and quicker recovery. While laparoscopic pyeloplasty was accompanied with the slow learning curve due to technically demanding and time-consuming intracorporal suturing, which has limited its widespread use. Robotic pyeloplasty and laparoscopic pyeloplasty were comparable regarding complication rate, success rate and operative time.

P117 Surgical management of Ureteropelvic Junction Obstruction (UPJO) in Neonates amid COVID-19 pandemic; Review of Literature and a Cohort Study in Iran

IntroductionThe current study presents a systematic review of literature on surgical management of ureteropelvic junction obstruction (UPJO) alongside an ongoing cohort study of neonates presenting with high grades of hydronephrosis due to UPJO requiring urgent treatment in a developing country amid the COVID-19 pandemic. The aim of this study is to investigate the efficacy and cost effectiveness of laparoscopic-assisted pyeloplasty.MethodsPatients’ demographics, clinical presentations and treatment outcomes are recorded. The cohort is classified into 3 groups based on type of surgical treatment offered including open, laparoscopic and laparoscopic-assisted pyeloplasty. All patients admitted with grade 3-4 hydronephrosis due to UPJO are included. Patients with UPJO as part of a complex multisystemic syndrome are excluded. Literature review was conducted from 2000/1/1 to 2020/1/1 to include all original research papers on surgical management of UPJO. The age group was limited to neonates (under 1 year-old).Results32 articles were included in the review. 20 papers (62.5%) recommended open pyeloplasty, 10 papers (31.3%) recommended laparoscopic pyeloplasty and 2 papers (6.25%) recommended laparoscopic-assisted pyeloplasty. The cohort study is currently recruiting patients treated by the 3 surgical approaches.ConclusionThe majority of studies are focusing on open pyeloplasty. However, as more surgeons are going through the learning curve of laparoscopic pyeloplasty, the trend is towards more laparoscopic management in the future. It is important to discover the advantages of laparoscopic-assisted approach as a new technique to improve the outcome and shorten the hospital stay amid the COVID-19 pandemic.

Diminished Systemic Amino Acids Metabolome and Lipid Peroxidation in Ureteropelvic Junction Obstruction (UPJO) Infants Requiring Surgery

Congenital anomalies of the urinary tract, and particularly of obstructive nephropathy such as ureteropelvic junction obstruction (UPJO) in infants, can later lead to chronic kidney disease and hypertension. Fundamental questions regarding underlying mechanisms remain unanswered. The aim of the present study was to quantitate the systemic amino acids metabolome in 21 UPJO infants requiring surgery (Group A) and 21 UPJO infants under conservative treatment (Group B). Nineteen healthy age-matched infants served as controls (Group C). Serum amino acids involved in several pathways and representative metabolites, including the L-arginine-derived nitric oxide (NO) metabolites nitrite and nitrate and the lipid peroxidation biomarker malondialdehyde (MDA) were measured by gas chromatography–mass spectrometry (GC–MS) methods using their stable-isotope labeled analogs as internal standards after derivatization to their methyl esters N-pentafluoropropionic amides (amino acids) and to their pentafluorobenzyl derivatives (nitrite, nitrate, MDA). The concentrations of the majority of the biomarkers were found to be lower in Group A compared to Group B. Statistical analysis revealed clear differentiation between the examined study groups. Univariate statistical analysis highlighted serum homoarginine (q = 0.006), asymmetric dimethylarginine (q = 0.05) and malondialdehyde (q = 0.022) as potential biomarkers for UPJO infants requiring surgery. Group A also differed from Group B with respect to the diameter of the preoperative anterior–posterior renal pelvis (AP) as well as regarding the number and extent of inverse correlations between AP and the serum concentrations of the biomarkers. In Group A, but not in Group B, the AP diameter strongly correlated with hydroxy-proline (r = −0.746, p = 0.0002) and MDA (r = −0.754, p = 0.002). Our results indicate a diminished amino acids metabolome in the serum of UPJO infants requiring surgery comparing to a conservative group.

Anuria and Hydronephrosis due to Ureteropelvic Junction Obstruction: A Case Report

A 3- year- old boy presented with abdominal pain and distension, lower extremities and facial edema, and anuria for several days that was associated with ureteropelvic junction obstruction (UPJO). Initial ultrasonography showed the presence of a massive bilateral hydronephrosis with UPJO and a computerized tomography (CT) scan without contrast revealed a massive hydronephrosis and hydroureter (grade 3). A follow-up study, after relief of ureteral obstruction, showed the reversal of this pattern. Blood biochemical tests revealed a severe acidosis, hyperkalemia, and a BUN/Cr ratio of more than 20. The patient underwent emergency nephrostomy. The general condition of the patient improved. Abdominal distention reduced, levels of urea and creatinine decreased, and acidosis resolved. A CT scan revealed an almost complete disappearance of the hydronephrosis and a normal ureter. Ureteropelvic junction obstruction (UPJO) was established as the cause of giant hydronephrosis.

Comparison between internal double J and external pyeloureteral stents in open pediatric pyeloplasty: A multicenter study

Anderson-Hynes dismembered pyeloplasty is considered the standard surgical treatment for ureteropelvic junction obstruction (UPJO). After pyeloplasty, stent drainage remains controversial. The commonly used stents are either an internal double-J (DJ) or an externalized pyeloureteral (PU) stents. We evaluated the outcome of using DJ versus PU stents following open pyeloplasty for UPJO in children. We retrospectively evaluated 175 patients who underwent primary open pyeloplasty in two tertiary hospitals. A total of 110 patients underwent internal DJ stent insertion (63%) while 65 patients (37%) underwent placement of external PU stent. The type of stent used at the time of surgery was according to surgeon preference and experience. Operative time, postoperative hospital stay, overall complications and success rates were compared between the two groups. The mean age was 3.8 years, and the mean follow-up was 4 years. Mean operative time was similar in the two groups (145min). Mean hospital stay was 3.7 and 4.2 days in DJ and PU stent, respectively (p=0.003) Summary Table . Postoperative complication developed in 9 out of 110 patients with DJ stent (8%), while complications developed in 6 out of 65 patients with PU stent (9%) (p=0.81). Success rate of pyeloplasty was 95.5% for DJ group versus 97% for PU group (p=0.63). Dismembered pyeloplasty remains the standard treatment of choice as a surgical management for UPJO. A debate is still there in respect to the method of PU anastomotic stenting and which stent can be used. The major advantage for external PU stents is that it can be removed safely in the outpatient clinic without any sedation preventing the risk of repeated exposure to general anesthesia. Internal DJ stent provides a shorter hospital stay and comparable complication and success rates compared with PU stent. If we manage to overcome the longer DJ stent duration and facilitate early removal by an easy mode, that does not require another anesthesia at that moment we can find the optimal stent for all pyeloplasty cases. The two types of stents are comparable as regard overall complication and success rates after pyeloplasty. Although internal DJ stent insertion provides a relatively shorter hospital stay, a second operating room visit and anesthesia for removal remains unavoidable.

Urinary extracellular matrix proteins as predictors of the severity of ureteropelvic junction obstruction in children

Ureteropelvic junction obstruction (UPJO) particularly represents a challenge in regard to management, as not all hydronephrosis (HN) represent a kidney-damaging state. Urinary biomarkers have been proposed as noninvasive tools. Extracellular matrix (ECM) proteins are associated with tissue fibrosis in the setting of UPJO and is poorly explored. To investigate whether urinary ECM proteins are useful to discriminate the severity of urinary obstruction on unilateral UPJO. Children with unilateral UPJO were prospective enrolled. Urinary (u) matrix metalloproteinases (MMP-1,-2,-9 and TIMP-1,-2) as well as clinical characteristics were measured in the following groups: 26 children with obstructive HN at initial diagnosis and after six months of dismembered pyeloplasty; 22 children with non-obstructive HN at diagnosis and after six months of observation; 26 children without any urinary tract condition, as the control group. Results were assessed statistically using for homogenous groups, a one-way analysis of variances (ANOVA) and for nonparametric groups, Mann-Whitney test or Kruskal-Wallis test was performed. ROC curves were performed. Baseline samples demonstrated a higher concentration of uMMP-1/Cr, uMMP-2/Cr, u-TIMP-1/Cr and u-TIMP-2/Cr in obstructive HN group; uMMP-9/Cr levels were higher in non-obstructive HN group and all studied biomarkers had lower concentrations for the control group. On follow-up, for the obstructive HN group, urinary concentration of uTIMP-1/Cr and uTIMP-2/Cr decreased, and uMMP-1/Cr, uMMP-2/Cr and uMMP-9/Cr increased when comparing preoperative to postoperative values. In the non-obstructive HN group, all proteins analyzed were stable after six months of observation. ROC curves analysis showed a promising diagnostic profile for the detection of obstructive HN for uTIMP-1/Cr (area under the curve -AUC-; of 0.692), uTIMP-2/Cr (AUC of 0.678) and for uMMP-2/Cr (AUC of 0.655). The severity of kidney obstruction could correlate with the urinary ECM proteins concentration in this study. This is concordant with prior studies demonstrating that a disruption of the balance of accumulation/degradation of the ECM proteins occur on obstructive uropathy. Limitations of our study include the older age of our patients and that these markers had no influence at all on the surgical decision. We demonstrate that obstructive HN have significantly higher uMMP-2, uTIMP-1 and uTIMP-2 concentrations. Particularly, uTIMP-2 levels were correlated to severity of obstruction and therefore, it might be a useful urinary biomarker to correctly allocate children with HN between surgical management vs follow-up. After pyeloplasty, uTIMP-1 and uTIMP-2 presented a progressive decrease postoperatively, which is also highly desirable for urinary markers.

Subadventitial dismembered pyeloureteroplasty – new surgical technique for correction of uretero-pelvic junction stenosis

Objective: Open or laparoscopic dismembered pyeloplasty has been the gold standard for the correction of ureteropelvic junction obstruction (UPJO) with a success rate of about 90%. Main insufficient feature of dismembered pyeloureteroplasty is interfering ureteral blood supply, which creates the prerequisites for the deterioration of the regeneration of the ureter and the possibility of developing restenosis. Methods: We offered and applied the new method – subadventitial resection of ureteropelvic junction (UPJ) to prevent damage to vessels of the distal part of pelvis and proximal part of the ureter. The protection of blood supply in this area should improve anastomosis regeneration and prevent fibrotic changes for long time, simultaneously providing better condition for the kinetic ability of the ureter. Results: Retrospective analysis of 106 patients with hydronephrosis, whom performed 108 open dismembered pyeloplasty (two patients were operated bilaterally) with subadventitial resection of UPJ from 1998-2020 years with a mean follow-up of 36 month shows that this technique has advantages over analogues. Conclusion: Our 22 years of experience shows that the technique of subadventitial resection of the ureter, allows us to save the ureteral blood circulation and thus creates conditions for better regeneration of the anastomosis and prevent later complications of dismembered pyelouretereroplasty.

Fetal Urinoma Due to Circulatory Disorders in an Umbilical Artery: Case Report

Fetal urinoma is defined as an encapsulated accumulation of extravasated urine within the perirenal space or retroperitoneum. It is an uncommon finding in prenatal practice, and the vast majority of known cases are strongly associated with the existence of a urinary obstruction, such as posterior urethral valves, ureteropelvic junction obstruction, or ureterocele. We report a unique case of prenatally detected fetal bladder urinoma that occurred in the absence of an apparent obstructive uropathy, but was associated with extensive ischemic necrosis and calcifications of adjacent bladder wall, coexistent with signs of vascular supply decompensation.

Сравнение функциональной магниторезонансной урографии и динамической нефросцинтиграфии в функциональной оценке обструкции пиелоуретерального сегмента у детей

PURPOSE In order to determine the role and significance of functional magnetic resonance urography (fMRU) in the diagnosis of ureteropelvic junction obstruction (UPJO), a comparative analysis of the results of fMRU and dynamic renal scintigraphy (DRS) was carried out. MATERIALS AND METHODS From January 2017 to December 2019, fMRU and diuretic DRS were performed in 36 patients (mean age 89+/-63 months). Boys - 26 (72.2%), girls - 10 (27.8%). Left-sided hydronephrosis was detected in 23 (63.9%) children, right-sided in 12 (33.3%) patients, and bilateral lesions in 1 (2.8%) patient (2 renal units (RU)). Antenatal hydronephrosis was detected in 9 (25%) patients, and postnatally in 27 (75%) patients. According to ultrasound data, grade II hydronephrosis occurred in 11 (29.8%) RU, grade III - in 21 RU (56.7%), and grade IV - in 5 RU (13.5%) according to the SFU classification. A diuretic test was performed in 26 patients. RESULTS Median and quartiles of differential renal function (DRF) according to fMRU data on the affected side were 37% [29; 43], and according to DRS - 46% [40;49]. When performing fMRU, a positive diuretic test was detected in 20 patients, 5 patients - negative and 1 patient - doubtful, and according to the DRS data, 12 patients had a positive test, 10 patients - negative and 4 patients - doubtful. Differences in DRF between fMRU and DRS varied between 0.7-33%. The average value of differences in DRF on the affected side was 11.3+/-8.5%. When comparing the results of DRF on the affected side, a moderate correlation was found on the Cheddock scale (r=0.59, p<0.05) between fMRU and DRS data. In comparison of the DRF using the Wilcoxon test, statistically significant differences were revealed (p<0,05). SUMMARY Our experience demonstrates the high potential of fMRU in terms of replacing the classical methods of diagnosis of UPJO in children, taking into account the high correlation coefficients between the results of fMRU and DRS. Standardization of the fMRU protocol will increase the diagnostic relevance of information and in the future will make fMRU the only necessary study to determine management tactics for patients with UPJO.