Primary Non-refluxing Megaureter Research Articles

Febrile Urinary Tract Infections in Children with Primary Non-Refluxing Megaureter: A Systematic Review and Meta-Analysis.

Knowledge of the baseline risk of febrile urinary tract infections in patients with primary non-refluxing megaureter can help clinicians to make informed decisions for offering continuous antibiotic prophylaxis. The primary objective of this systematic review was to determine the pooled prevalence of febrile urinary tract infections in patients with primary non-refluxing megaureter selected for primary non-surgical management independent of associated attributed risk factors at initial presentation in order to assess the value of continuous antibiotic prophylaxis. MEDLINE, EMBASE, and Cochrane Controlled Trials Register electronic databases were searched for eligible studies without language and time restriction. The systematic review was carried out following the recommendations of the Cochrane Collaboration and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. (PROSPERO registration number CRD42018104752). Of 25 871 records, 16 studies (n=749 patients) were eligible for inclusion. The overall pooled prevalence of febrile urinary tract infections in patients with primary non-refluxing megaureter was 14.35% (95% confidence interval: 8.8-22.6). The calculated number needed to treat for patients on continuous antibiotic prophylaxis to prevent one single febrile urinary tract infection over the course of 1-2 years would be 4.3. Based on the current available evidence the use of continuous antibiotic prophylaxis for children with PM selected for primary non-surgical treatment should be taken into consideration, at least in patients with urinary outflow impairment, higher grade of ureteral dilatation, and for children in the first months of life.

Primary Non-refluxing Megaureter: Analysis of Risk Factors for Spontaneous Resolution and Surgical Intervention.

Background: The risk of febrile urinary tract infection (fUTI) in children with primary non-refluxing megaureter (PM) has been extensively studied in the literature, however, a paucity of information exists regarding risk factors for surgical intervention and spontaneous resolution. We sought to analyze data from our prospectively collected PM cohort to determine risk factors that would predict surgery and resolution in this population.Methods: Patients with PM were identified from our prospectively-collected prenatal hydronephrosis (HN) database from 2008 to 2017. Primary outcomes included surgical intervention and hydroureter resolution. Spontaneous resolution was defined as ureteral dilation <7 mm at last follow-up. Age at presentation, gender, development of fUTI, HN grade [low (SFU I/II) vs. high (SFU III/IV)], anteroposterior diameter (APD) measurements and ureteral diameter at baseline and last follow-up were recorded. Univariate and multivariable analyses (binary logistic and Cox regression) were performed.Results: Of 101 patients, 86 (85%) were male, and 80 (79%) had high grade HN. Median age at baseline and last follow-up were 2 (0–23) and 29 (2–107) months, respectively. Overall, 23 (23%) patients underwent surgery at a median age of 22 (3–35) months. Mean ureteral diameter was larger in surgical patients vs. those treated non-surgically (14 ± 4 vs.11 ± 3 mm; p < 0.01). Of the 78 (77%) non-surgical patients, 43(55%) showed resolution of their ureteral dilation at a median age of 24(4–56) months. Survival analysis demonstrated that 12 patients resolved by year 1, 22 by year 2, 30 by year 3, 40 by year 4, and 43 by year 5. However, when considering resolution as APD <10 mm, 62(79%) children resolved their HN by last follow-up (29 months). Univariate and multivariable analyses (Table 1) revealed that high-grade HN at baseline, development of fUTI, and ureteric dilation ≥14 mm were significant risk factors for surgical intervention. Cox regression (Figure 2) found that ureteral dilation <11 mm was the only independent risk factor significantly associated with PM resolution (Table 2).Conclusion: Patients with PM and high-grade HN, as well as individuals with ureteral dilation ≥14 mm and fUTI were more likely to undergo surgical intervention. Ureteral dilation <11 mm was the only independent risk factor significantly associated with spontaneous resolution of PM.

Side-to-Side Refluxing Nondismembered Ureterocystotomy: A Novel Strategy to Address Obstructed Megaureters in Children.

A nonrefluxing megaureter is a relatively common cause of antenatal hydronephrosis. Although nonoperative management is favored, surgical intervention is sometimes warranted. However, there is controversy regarding the best approach, particularly in young children. We describe our experience with nondismembered side-to-side refluxing ureterocystotomy as a simple option to address obstruction. Between January 2012 and January 2017, 32 patients underwent ureterocystotomy at 4 referral centers in North America. Demographics, surgical indications, complications, need for further interventions and change in hydronephrosis were captured. Patients were monitored clinically and with serial ultrasounds. Mean age at surgery was 3.7 months (range 0 to 33) and 25 (78%) patients were male. Unilateral procedures were performed in 29 patients. All patients were initially identified based on the presence of antenatal hydronephrosis and symptoms developed in 10. The procedure was conducted for primary nonrefluxing megaureter in 27 patients and to address secondary obstruction in the remainder. Mean followup was 34.3 months (range 6 to 58). At the most recent evaluation most children demonstrated significant improvement in dilation (86%). To date, 6 patients have undergone further procedures, including a circumcision and 2 ureteral reimplantations for recurrent infections. Our results suggest that side-to-side refluxing ureterocystotomy is a straightforward, minimally invasive alternative for the surgical management of nonrefluxing megaureter. Despite the trade-off of relieving obstruction and creating reflux, it can be considered a potentially definitive procedure in patients who remain infection-free, particularly circumcised boys. Extended followup with close monitoring is critical to document long-term results with this intervention.

Primary non-refluxive megaureter in children: single-center experience and follow-up of 212 patients.

Primary non-refluxing megaureter (pMU) is a multifaceted and challenging congenital pathology of the urinary tract. We report our 23-year experience with this anomaly in terms of presentation, diagnostic work-up and management. We retrospectively reviewed the medical records of 212 children diagnosed with pMU between 1986 and 2009 at our institution. Mean follow-up was 45.17 (0-192) months. Of the total, 168 (79%) children presented with upper urinary tract dilation on perinatal ultrasound screening. In 44 (21%) patients, the diagnosis was made following diagnostic work-up of a urinary tract infection (UTI, 18%) or flank pain (3%). In total, 203 of 254 pMUs (79.9%) were successfully treated conservatively during the 23-year observation period. Forty-eight children (23%) underwent ureteric reimplantation. UTIs occurred in 91 of 212 children (43%). Of these, 41 (45%) occurred despite antibacterial infection prophylaxis. Within the past three decades, there has been a marked shift from surgical toward conservative therapy at our institution. Neonatal renal ultrasound is the method of choice to timely identify children with pMU and, alongside dynamic renography, to monitor the clinical course. Nowadays, only a minor subset of children with asymptomatic course requires surgical correction. Antibacterial prophylaxis has the potential to reduce the risk of febrile UTIs. Prospective randomized studies are warranted to provide evidence of the beneficial effect of antibacterial prophylaxis.

Isolated low initial differential renal function in patients with primary non-refluxing megaureter should not be considered an indication for early surgery: A multicentric study

Low initial differential renal function (DRF) in patients with primary non-refluxing megaureter (PNRM) is considered an indication for surgery as are an increase of dilatation and symptoms. We hypothesized that low DRF is not necessarily a result of obstruction, but may be due to impaired development of the upper urinary tract. Thus, in the absence of symptoms, there is a low risk for further loss of renal function. This study aimed to assess whether initially low DRF is a reliable indicator of obstruction. We reviewed data from four university centers between 1995 and 2010. Patients under 12 months of age with unilateral primary non-refluxing megaureter (PNMR) and a DRF between 10% and 40%, and followed minimally 24 months, were included. Patients were placed in two groups based on management: group A, surgical; group B, conservative. The dynamics of DRF in relation to age and type of treatment was studied. In each patient we recorded the earliest (initial) DRF, the last known (final) DRF, the age when MAG-3 scans were performed and the type of treatment. From 25 patients, 16 were treated surgically (group A) and 9 followed conservatively (group B). The initial mean DRF in group A was 33.1% and in group B 34.5%, at a mean age 3.0 and 3.6 months, respectively. The final mean DRF in group A was 40.1% and in group B 43%, at a mean age 59.9 and 46.3 months, respectively. Using two-way repeated ANOVA (age [initial DRF, final DRF] vs. group [group A, group B]), we found non-significant difference between the groups in the DRF, F (1, 21)=0.96, p=0.338, while we observed statistically significant and similar increase from the initial to final DRF in both groups, F (1, 21)=16.66, p=0.001 (Figure). This is the first study focusing on the evolution of renal function in patients with PNRM and low initial DRF. Results suggest that the diagnosis of obstruction is inaccurate in most infants with unilateral PNRM if it is based on low initial DRF only. Renal deterioration rarely occurs in asymptomatic patients, and even profoundly impaired kidneys have potential for improvement. Limitations of our study include retrospective design and lack of standardization of treatment among the four centers. Low DRF in asymptomatic and anatomically stable patients with PNMR should not be considered an indication for early surgery. These findings challenge current practice and should be confirmed by a prospective study.

The Fate of Primary Nonrefluxing Megaureter: A Prospective Outcome Analysis of the Rate of Urinary Tract Infections, Surgical Indications and Time to Resolution

We examined data on a cohort of patients with primary nonrefluxing megaureter to determine risk factors for febrile urinary tract infection, indications for surgery and time to resolution. The records of patients younger than 24 months with primary nonrefluxing megaureter were prospectively captured from 2008 to 2015. Six a priori defined variables were studied, including gender, circumcision status, hydronephrosis SFU (Society for Fetal Urology) grade (low--1 and 2 vs high--3 and 4), continuous antibiotic prophylaxis use, ureteral dilatation (greater than 11 mm) and tortuosity. Univariate analyses and Cox hazard regression were done for febrile urinary tract infection risk factors. Resolution trends were analyzed using Kaplan-Meier curves. Mean ± SD age at the first clinic visit was 3.7 ± 4 months and mean followup was 26.3 ± 16.6 months. Of 80 patients with primary megaureter 66 (83%) had high grade hydronephrosis, 72 (90%) were male, 21 (26%) were circumcised and 40 (50%) had ureteral dilatation greater than 11 mm at baseline. Overall continuous antibiotic prophylaxis was prescribed to 34 patients (43%) and febrile urinary tract developed infection in 27 (34%) at a mean age of 5.8 months (median 3, range 1 to 24). Cox regression identified uncircumcised male gender (HR 3.4, 95% CI 1.1-10.7, p = 0.04) and lack of continuous antibiotic prophylaxis (HR 4.1, 95% CI 1.3-12.7, p = 0.01) as independent risk factors for febrile urinary tract infection. The 19 surgical patients (24%) had a larger mean ureteral diameter immediately preoperatively than those who did not require surgery (17 ± 5 vs 12 ± 4 mm, p <0.01). Kaplan-Meier curves showed that 85% of primary nonrefluxing megaureters that did not require surgery resolved in a median of 17 months. Febrile urinary tract infection developed in 34% of patients with primary nonrefluxing megaureter within the first 6 months of life. Circumcision and continuous antibiotic prophylaxis significantly decreased febrile urinary tract infection rates in those infants. Ureteral diameter 17 mm or greater was significantly associated with a higher rate of surgical intervention. Overall 76% of megaureters resolved during a median followup of 19 months.

Conservative management of primary non-refluxing megaureter during the first year of life: A longitudinal observational study

There is a lack of prospective studies that include a selected population of patients with primary non-refluxing megaureter (PM). Thus, a longitudinal observational study was designed to follow from birth a selected population of children with PM; all were antenatally diagnosed. In this paper, the outcomes observed in the first year of life are presented. The primary aim was to follow the natural history of PM. The secondary aim was to monitor the onset of any potential complications such as urinary tract infections (UTIs), need for hospitalization and need for surgical correction. All children with antenatally diagnosed PM, born between January 2007 and December 2013, were prospectively followed with observational management: renal ultrasonography and clinical evaluation on a 3-month basis; urinalysis and culture in case of symptoms; and mercaptoacetyltriglycine (MAG3) nuclear scan once older than 1 month. Children presenting at birth with mild urinary tract dilatation were included in Group A; those with moderate-to-severe dilatation were included in Group B. Continuous antibiotic prophylaxis (CAP) was administered to Group B. Forty-seven children (44 males, three females) with 58 PM were included in the study. The participants and their corresponding outcomes are shown in the summary Table. The presence of obstruction at renogram was a significant predictor of UTIs and hospitalization. The strengths of this study were its prospective nature and its very consistent population. A limitation was the lack of control groups. The results regarding the negligible incidence of complications in Group A and the residual incidence of febrile UTIs (20%) and hospitalization (17%) in Group B, even with CAP, are in line with previous literature. In contrast, there was a higher risk of UTIs observed in children aged older than 6 months. Resolution or improvement is expected in all cases of PM with mild postnatal dilatation, and close to 60% of those with moderate or severe dilatation. Surgery is rarely performed on children younger than 1 year of age. It is safe to observe children with mild urinary tract dilatation without CAP, because the incidence of UTIs is negligible. In those presenting with moderate or severe urinary tract dilatation, despite CAP, a residual incidence of UTIs is seen, and symptomatic patients often require hospitalization. However, UTIs are well tolerated and do not seem to modify outcome. Cases showing obstruction on the MAG3 scan seemto be at higher risk of UTIs and hospitalization.

This Month in Pediatric Urology

No AccessJournal of UrologyThis Month in Pediatric Urology1 Sep 2013This Month in Pediatric Urology Laurence S. Baskin Laurence S. BaskinLaurence S. Baskin More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.06.005AboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "This Month in Pediatric Urology." The Journal of Urology, 190(3), pp. 827–828 References 1 : Outcomes of targeted treatment for vesicoureteral reflux in children with nonneurogenic lower urinary tract dysfunction. J Urol2013; 190: 1028. Link, Google Scholar 2 : Long-term followup of primary nonrefluxing megaureter. J Urol2013; 190: 1021. Link, Google Scholar 3 : Long-term outcomes for males with disorders of sex development. J Urol2013; 190: 1038. Link, Google Scholar 4 : Uroflowmetry nomograms for healthy children 5 to 15 years old. J Urol2013; 190: 1008. Link, Google Scholar 5 : Prospective study using a new bulking agent for the treatment of vesicoureteral reflux: polyacrylamide hydrogel. J Urol2013; 190: 1034. Link, Google Scholar 6 : Dysfunctional elimination syndromes—how closely linked are constipation and encopresis with specific lower urinary tract conditions?. J Urol2013; 190: 1015. Link, Google Scholar © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 190Issue 3September 2013Page: 827-828 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Laurence S. Baskin More articles by this author Expand All Advertisement PDF DownloadLoading ...

Long-Term Followup of Primary Nonrefluxing Megaureter

We evaluated outcomes of nonoperative management of primary nonrefluxing megaureter at long-term followup to identify clinical predictors of spontaneous resolution. A total of 75 patients (88 primary megaureters) were diagnosed between 1990 and 2005 and followed for more than 6 months. Of the patients 63 (74 primary megaureters) were included in the main study population. Indications for surgery were obstructive hydroureteronephrosis, functional impairment and persistent symptoms. Of the 74 primary megaureters 20 (27%) required surgery up to 7 years after diagnosis. Surgery was not indicated in 82% of primary megaureters with grade I or II hydronephrosis vs 62.9% of those with grade III or higher hydronephrosis (difference not significant), nor in 76.5% of types I and II primary megaureters vs 33.3% of type III primary megaureters (p = 0.040), 78.7% of renal units with differential function 40% or greater vs 0% with differential function less than 40% (p = 0.027), 80% of primary megaureters with a nonobstructive washout pattern vs 44.4% with an intermediate/obstructive pattern (p = 0.032), 67.9% of patients with perinatal presentation vs 25% with postneonatal presentation (p = 0.008) or 63.2% of patients presenting with symptoms vs 76.4% of those who were asymptomatic (difference not significant). On multivariate analysis age at presentation and washout pattern were significant predictors of spontaneous resolution. Most cases of primary megaureter resolve spontaneously or improve without loss of function or development of symptoms. Careful observation allows surgery to be delayed beyond the neonatal period in most patients. Long-term followup is recommended because symptoms can develop years later. Washout pattern and age at presentation are statistically significant predictors of spontaneous resolution.

Resolution of primary non-refluxing megaureter: An observational study

AimA prospective review of conservative management of primary non-refluxing megaureters (PM) was performed to determine the time taken for resolution (TTR) and complications. Material and MethodsPatient details were obtained from a prospectively maintained database from January 1, 2003, to December 31, 2011. The clinical features of USS and MAG3 findings were analyzed. All had annual USS and MAG 3 scans two yearly (and whenever necessary). ResultsFifty ureteric units (UU) in forty-four patients (six bilateral) were studied. There were thirty-three (75%) males. In the unilateral PM, 22/38 were left-sided. Children were classified according to the lower ureteric diameter (UD) into two groups: Group A (Gp A) UD <10mm (n=25, 26 UU), and Group B (Gp B) UD ≥10mm (n=19, 24 UU). Antenatal diagnosis was achieved in 21 (84%) UU in Gp A and 11 UU (58%) in Gp B.In Grp A, the median presenting UD was 6 (range 4–9)mm, and 76% resolved completely over a median duration of 60 (18–204)months. In Grp B, the median UD was 15 (10–27)mm, and 17% resolved completely over a median duration of 102 (42–210)months. Two developed ureteric calculi (removed ureteroscopically). Three with complications (obstructive drainage pattern in MAG 3 with decreasing function and debilitating infections) underwent ureteric tapering and reimplantation. An obstructed megaureter resolved after endoscopic dilatation. Another underwent temporary ureterostomy on developing hypertension. ConclusionThe exclusively conservative management of PM seems highly successful within Group A (i.e. UD <10mm). Complications (stones, decreasing renal function) were more common with higher UD. TTR seems to take over five years in both groups.

Impact of Ectopic Insertion on Treatment Outcome of Primary Non-refluxing Megaureter

To investigate the characteristics of primary non-refluxing megaureter with ectopic insertion and its effects on renal function. Of 118 patients diagnosed with primary non-refluxing megaureter, we retrospectively studied 33 patients who underwent surgical treatment. Depending on the position of ureteral insertion, patients were classified as having either an ectopic or orthotopic megaureter; clinical characteristics and renal function, were analyzed. Among the 36 primary non-refluxing megaureters, 7 (19.4%) had ectopic megaureter. A total of 34.5% of the orthotopic megaureter and all ectopic megaureter cases were women (P = .003). The mean value of maximum ureteral diameter was significantly wider for ectopic than for orthotopic megaureter (16.3 vs 12.1 mm, respectively, P = .029). Mean preoperative differential renal function (DRF) were 36.4% and 43.0% for ectopic and orthotopic megaureters, respectively (P = .164). After surgery, the mean DRF of ectopic megaureter had decreased from 50% to 18.8%, whereas the mean DRF of orthotopic megaureter was 42.9% (P <.001). At the time of surgery, the mean age of patients was 4.6 months in the ectopic megaureter and 16.7 months in the orthotopic megaureter (P = .005). In our study, all the cases of an ectopic megaureter occurred in women, and the ureteral dilatation was comparatively more severe than in orthotopic megaureters. In addition, despite early surgical treatment, renal function deteriorated gradually. Further analyses are necessary to determine whether earlier surgical intervention for preventing deterioration of renal function is worthwhile or not.

Primärer Megaureter

A primary megaureter is an anomaly with a prevesical or overall dilated ureter of more than 6mm in diameter. It is important to distinguish between cases of primary non-refluxing and primary obstructive-refluxing megaureters, as the treatment of both is completely different. The basic diagnostic work-up includes ultrasonography and voiding cystourethrography. Diuretic renography is used to detect split renal function and the degree of upper urinary tract obstruction. In most cases of primary non-refluxing megaureter surgical treatment is unnecessary due to the high remission rate, whereas obstructive refluxing megaureters commonly only need to be corrected. Antibiotic prophylaxis may be indicated in infants with a primary obstructive megaureter during the first 6 months of life due to a higher risk of complications due to pyelonephritis especially in this age group.

Antibiotic prophylaxis in antenatal nonrefluxing hydronephrosis, megaureter and ureterocele

Observation is a conservative management option in infants with nonrefluxing hydronephrosis, primary nonrefluxing megaureter and ureterocele diagnosed postnatally following antenatal detection of hydronephrosis. Antibiotic prophylaxis might be a sensible regimen under these circumstances to prevent UTI in this population who are potentially at increased risk. However, studies examining the efficacy of prophylactic antibiotics are sparse in this setting. For each condition, prophylactic policies seem extremely variable, and UTI rates vary widely with comparable rates reported between patients followed on and off antibiotics. Overall, antibiotic prophylaxis seems unnecessary in patients with isolated low-grade hydronephrosis. Patients with high-grade nonrefluxing hydronephrosis seem at increased risk of UTI, with risk further increasing in patients with associated ureteral dilatation (hydroureteronephrosis) irrespective of the presence of a ureterocele. Obstruction might be an additional independent risk factor, but the diagnosis of obstruction is often possible only in retrospect. The data available suggest that infants are the most at risk of UTI during the first 6 months of life, particularly if they undergo catheterization during workup examinations. Thus, antibiotic prophylaxis might be prudent during the first 6-12 months of life in patients with high-grade hydronephrosis and hydroureteronephrosis with or without ureterocele, and particularly before completion of the diagnostic workup. Paediatric urologists are urged to embark on controlled trials to compare patients followed with and without antibiotic prophylaxis.

Urinary Tract Ultrasonography Prior to and After 3-Hour Free Bladder Drainage: A New Diagnostic Approach for Primary Non-Refluxing Megaureter

Purpose The primary non-refluxing megaureter (MGU) is one of the common causes of hydronephrosis in children. The aim of this study was to introduce ultrasonography (US) prior to and after 3-hour free bladder drainage as a simple method to distinguish primary obstructive, non-refluxing MGU from secondary non-obstructive, non-refluxing MGU. Material and Methods A total of 200 children with non-refluxing MGU were evaluated. Ureteral diameter was measured using US in all children with full and empty bladder; the appropriate-size urethral catheter was inserted and remained for 3 hours. Ultrasonography was repeated for reevaluating the degree of hydroureteronephrosis and ureteral diameter. All participants also underwent 99tm-DTPA scan for comparison to US. Results The mean age of children (55 females and 145 males) was 4 ± 3.4 years (range, 1 month to 11.3 years). The mean ureteral diameter prior to free bladder drainage was 11 mm (range, 6–25 mm). After catheterization, the ureteral diameter reduced in 148 children (non-obstructed) by an average of 7 mm, (range, 4-17 mm) and remained unchanged (obstructed) in 52 children. Of patients who were diagnosed as non-obstructive MGU by 99tm-DTPA (n=152), 130 patients were confirmed by US and among those with partial obstructive MGU in 99tm-DTPA (n=48), 30 patients showed no reduction in ureteral diameter in US. Sensitivity and specificity for 3-hour bladder free drainage were 83% and 62.5%, respectively. Positive predictive value and negative predictive value were 80% and 57%. Conclusions A 3-hour bladder free drainage is considered as a simple, reliable and safe diagnostic alternative method for conventional modalities (renal scan / cystoscopy / surgery) for differentiation between primary obstructive, and secondary non-obstructive, non-refluxing MGU.

Endoscopic placement of double-J ureteric stents in children as a treatment for primary obstructive megaureter

Aim:To determine the efficacy and potential complications of double-J ureteric stents in the treatment of persistent or progressive primary obstructive megaureter in pediatric patients within our institution.Materials and Methods:A retrospective case-note review of all patients with double-J ureteric stents, between 1997 and 2004, was performed. In all, 38 stents were inserted in 31 patients aged between 2 months and 15 years of age. Complications and results of follow-up investigations and the need for follow-up investigations were recorded. Patients were followed up clinically and radiologically for a minimum of 2 years following stent insertion.Results:Endoscopic placement of double-J ureteric stents in childhood is straightforward and complications are uncommon (8/38 insertions). In non-resolving or progressive primary non-refluxing megaureter, double-J ureteric stenting alone is effective with resolution of primary non-refluxing megaureter in 66% of cases (25/38 insertions).Conclusions:Ureteric stenting provides an alternative to early surgery in patients with primary non-refluxing megaureter. The youngest patient in our series was 2 months old at the time of endoscopic ureteric double-J stent insertion. Endoscopic placement of ureteric double-J stents should be considered as a first-line treatment in the management of persistent or progressive non-refluxing megaureter leading to progressive hydronephrosis or pyonephrosis.

The Fate of Prenatally Diagnosed Primary Nonrefluxing Megaureter: Do We Have Reliable Predictors for Spontaneous Resolution?

To compare predictive values of current morphologic parameters with congenital renal damage associated with severe megaureter. A retrospective analysis was performed using records of 37 patients (50 megaureters) referred before birth for a primary megaureter. Mean follow-up was 26 months (range, 1 to 8 years). Dilatation resolved spontaneously in 46 of 50 ureters. Only 4 of 37 patients required surgery (10.8%) after a mean follow-up of 58 months (range, 32 to 80 months). Average time to resolution was 24 months (range, 1 to 82 months) and was independent from sex, side, and bilaterality. A weak correlation was found with initial anteroposterior pelvic diameter, ureteral diameter, and separate function at renogram. A significant correlation (P <0.02) was found between megaureter type and time elapsed to spontaneous resolution. As far as differential function was concerned, mean values were significantly lower among type III megaureters, which had the lowest rate of resolution. The fate of severe megaureter seems strongly influenced by congenital renal damage secondary to a developmental abnormality of the ureteric bud. A poor resolution rate has to be expected in these cases; surgery must be reserved for symptomatic cases but has no influence on pre-existing renal damage.

Radiographic Changes Following Excisional Tapering and Reimplantation of Megaureters in Childhood: Long-Term Outcome in 46 Renal Units

Despite the routine use of renal ultrasonography to document progressive improvement in hydronephrosis following ureteral tailoring and reimplantation of megaureters, there have been few reports characterizing the serial radiographic changes to be expected following this procedure. We evaluated the radiographic outcomes following surgical repair of megaureters at single institution, and assessed potential preoperative factors for predicting outcome. We conducted a retrospective analysis of all patients who underwent surgical correction of clinically significant megaureters at our center between 1996 and 2003. Demographic data, indications for surgery, and preoperative and postoperative radiographic imaging data were recorded. A total of 46 megaureters (39 patients) were tapered and reimplanted. Average patient age at surgery was 4.0 years (range 5 months to 19 years). Indications for surgery included recurrent or breakthrough urinary tract infections, decreased renal function and increased hydroureteronephrosis. Mean followup was 3.9 years (range 4 months to 7 years). Postoperative voiding studies showed vesicoureteral reflux in 3 reimplanted ureters (7%). There was no evidence of obstruction on postoperative nuclear renal scans in any patient. Renal ultrasonography revealed improvement or resolution of hydroureteronephrosis in 29 reimplanted units (63%). In general, male patients, those operated on at a younger age and those with a lower preoperative grade of hydronephrosis were most likely to demonstrate improvement or resolution of hydronephrosis. The best results were seen in ectopic megaureters, followed in decreasing order by refluxing megaureters, megaureters associated with ureteroceles and primary obstructive megaureters. Despite functional improvement on postoperative radiographic imaging, it is not uncommon to see persistent hydroureteronephrosis following excisional tapering and reimplantation of megaureters in childhood.

Megauréter primario no refluyente detectado prenatalmente

Most primary non-refluxing megaureters resolve spontaneously and the indications for surgery are not sufficiently well established. To analyze the clinical features, treatment and outcome of asymptomatic primary non-refluxing megaureter. We retrospectively studied 58 infants with primary non-refluxing megaureter. The diagnostic methods used were renal ultrasound, renal isotopic renogram, DMSA scan, and evaluation of renal function. The mean age at postnatal diagnosis was 24 days. The mean follow-up was 4 years. Sixty-nine percent of the patients were male. Fifty-seven percent were left megaureters and 22% were bilateral (71 affected renal units). Eleven percent of megaureters were grade I, 48% were grade II, and 41% were grade III. Only nine patients (15%) received surgical treatment. The indications for surgical treatment were severe megaureter (3/9 patients; 33%), prolonged T1/2 (3/9 patients; 33%), reduced function (1/9 patients; 11%), prolonged T1/2 plus reduced function (1/9 patients; 11%) and increased dilation (1/9 patients; 11%). The mean age at surgery was 7 months. Outcomes in the non-surgical group (85% of the patients; 60 renal units) were as follows: 90% of megaureters were corrected or improved on ultrasound scan and 10% showed no change. In the first renogram, function was low in 4/60 kidneys (7%) and T1/2 was prolonged in 3/60 (5%). Finally, all kidneys in the non-surgical group had normal function, except one, which was injured from the beginning. T1/2 was normal in all kidneys. Outcomes in the surgical group (10 megaureters) were as follows: 80% of megaureters were corrected or improved after surgical intervention and 20% showed no change. At diagnosis, 4/10 kidneys (40%) had reduced function. In the post-surgical renogram 2/10 kidneys (20%) continued to show reduced function, 1/10 kidney (10%) showed restored renal function, and 1/10 kidney (10%) was nephrectomized. Initial T1/2 was prolonged in 4/10 patients (40%), and after surgery T1/2 was normal in all patients. The final DMSA scan showed 5/71 kidneys (7%) with irreversible damage (one slightly injured, two moderately injured, and three severely injured). The remaining 66 kidneys were normal. Overall renal function and blood pressure were normal in all patients. Primary non-refluxing megaureter is usually a functional and benign congenital malformation that resolves during the first months of life. Although the malformation can persist, only a few patients require surgical treatment. Most authors agree that initial treatment should not be surgical and that surgery should be reserved for patients who develop ureteral dilation, a decrease in differential renal function, and/or severe symptoms during follow-up. In a few patients (7% of our series), the renal unit belonging to the megaureter shows irreversible congenital injury. In these patients, surgery is not useful.

MP-16.10: Children with a primary non-refluxing megaureter: a shift in presentation and treatment

MP-16.10: Children with a primary non-refluxing megaureter: a shift in presentation and treatment

Double- J stent insertion across vesicoureteral junction—is it a valuable initial approach in neonates and infants with severe primary nonrefluxing megaureter?

Objectives To evaluate the role of double- J stent insertion in perinatally detected primary nonrefluxing megaureters as a method to temporize treatment in patients with impaired renal function or to prevent function loss in patients treated expectantly, but deemed at high risk of deterioration. Methods Two neonates and 8 infants with a ureter greater than 10 mm and an obstructive excretion pattern, including 3 cases with renal function less than 40%, were selected to undergo double- J stent insertion for a 6-month period. Patients underwent surgery if the ureter redilated and the excretion pattern was obstructive at reassessment 3 months after stent removal. Results Stents were placed at a median age of 3 months (range 1 to 6). Open insertion was necessary in 5 cases (50%). Seven patients (70%) developed stent-related complications (five breakthrough urinary infections) requiring early stent removal in 2 (20%). Five patients (50%) underwent surgery at a median age of 14 months (range 13 to 27), including the 3 patients with decreased renal function at presentation. None required ureteral tapering. None experienced any renal function loss with respect to the initial evaluation. Conclusions Double- J stent insertion across the vesicoureteral junction allows for effective internal drainage of primary nonrefluxing megaureters, but at the cost of a 70% morbidity rate and various technical drawbacks. Therefore, stenting should be considered on a case-by-case basis. The procedure seems valuable to temporize surgery in patients with decreased renal function. However, given the associated morbidity, it seems impractical for patients with preserved function selected in accordance with currently available prognostic indicators.