Hydronephrosis In Children Research Articles

Magnetic resonance urography for diagnosis of pediatric ureteral stricture

PurposeUreteral stricture is a rare cause of hydronephrosis in children and is often misdiagnosed on ultrasound (US) and diuretic renal scintigraphy (DRS), requiring intraoperative diagnosis. We evaluated ureteral strictures diagnosed by magnetic resonance urography (MRU) at our institution. Materials and methodsChildren with ureteral stricture who underwent MRU were identified. Patient demographics, prior imaging, MRU findings, and management were assessed. The efficacy of MRU in diagnosis of stricture was compared with US and DRS. Patients with ureteropelvic or ureterovesical junction obstruction were excluded. ResultsTwenty-eight ureteral strictures diagnosed by MRU between 2003 and 2013 were identified; 22% of strictures were diagnosed by DRS ± US. The mean age at MRU diagnosis was 2.4 years (range 4 weeks–15 years). Hydronephrosis was the most common presentation, accounting for 20 (71%) cases. Other etiologies included pain (3), incontinence (2), and urinary tract infection, cystic kidney, and absent kidney, present in one case each. A mean of 2.7 imaging studies was obtained prior to MRU diagnosis. Twenty-one (75%) ureteral strictures required surgical intervention, with the approach dependent upon location. ConclusionsMRU provides excellent anatomic and functional detail of the collecting system, leading to accurate diagnosis and management of ureteral stricture in children.

Hydronephrosis in children

Hydronephrosis is a common illness in children and consists in the dilatation of the renal collector system. It may be congenital, and in this case is called fetal hydronephrosis, or it can be acquired, which is less frequent. The fetal hydronephrosis may be diagnosed during the intrauterine life through obstetric ultrasound. Mild to moderate dilatations may resolve spontaneously before or after birth. However, larger dilatations can be causes of urinary tract infection, damage to the renal parenchyma, and may require surgical treatment. The main causes of persistent fetal hydronephrosis after birth are ureteropelvic junction stenosis, vesicoureteral reflux, ureterovesical junction stenosis, ureteric duplication associated or not with ureterocele, and posterior urethra valve. In relation to the acquired hydronephrosis, the most common etiology is the angulation of the proximal ureter resulting from an anomalous polar vessel; however, it can also be due to ureterolithiasis, which is uncommon. In these cases, the hydronephrosis is usually diagnosed as the result of propaedeutics of chronic recurrent abdominal pain in older children. The initial conduct in cases of fetal hydronephrosis, shortly after birth, is the use of urinary tract ultrasound to confirm and classify the degree of hydronephrosis. The ultrasound findings will assist to decide if it is necessary to extend the propaedeutics or maintain a waiting conduct. The follow-up by a nephrologist and pediatric-surgeon in the subsequent treatment of these children is

Hybrid procedure for pyeloplasty in infants and young children with ureteropelvic junction obstruction is a safe and effective alternative

Ureteropelvic junction obstruction (UPJO) is a common congenital urinary tract anomaly causing hydronephrosis in children. Laparoscopic pyeloplasty has become a popular and effective method to treat UPJO both in children and adults, but seems controversial in neonates or infants. From January 2007 to May 2012, patients with UPJO aged <18 years undergoing operations at our institute were included in this study. By retrospectively reviewing medical charts, the demographic data, presentation, laterality, etiology, operative time, length of hospital stay, stents, drainage tubes, and postoperative complications were recorded. Surgical outcomes were evaluated based on renal sonography and Lasix diuretic renography. A total of 47 patients (40 boys and 7 girls) were enrolled initially, but seven patients who were complicated with other congenital anomalies of the urinary system or who underwent surgery at other hospitals were excluded. Among these 40 patients, 21 had open pyeloplasty (Group I), eight who were younger than 1 year old or weighed <10 kg had a hybrid procedure (Group II), and 19 had laparoscopic surgery (Group III). The mean age was younger in Groups I and II because the selected procedure was nonrandomized. The operative time and the duration of perianastomotic drainage were longer in Groups II and III. There was no significant difference with regard to successful resolution of UPJO among the three groups. In infants or young children (<1 year old or weighing <10 kg) with UPJO, the hybrid procedure of pyeloplasty may be considered as a safe, effective, and less time-consuming alternative to laparoscopic surgery, and most importantly, confirms the security of the anastomosis.

Hydronéphrose géante chez l’enfant : à propos d’une observation

Giant hydronephrosis in children is uncommon. Congenital ureteropelvic junction obstruction is the most frequent cause. The CT scan is very important for the diagnosis. We report on a case of hydronephrosis in a 12-year-old child who presented with enormous abdominal distension. The treatment included nephrectomy after waiting nephrostomy. The current literature is also reviewed.

Outcome of Exernal and Internal Drainage of Urine after Anderson Hynes Pyeloplasty - A Comparative Study

Background: Hydronephrosis in children is a common abnormality of the kidney. Surgical intervention in patient with hydronephrosis is to improve urinary drainage and to preserve renal function. Surgery (Anderson Hynes pyeloplasty: A-H pyeloplasty ) can be done with or without (Nephrostomy tube) D-J stent.Here we are describing our comparative experience between A-H pyeloplasty with D-J stent and A-H pyeloplasty with nephrostomy tube, at Bangabandhu Sheikh Mujib Medical University(BSMMU) to show the postoperative advantages of the former over the latter. Objectives: To assess functional outcome after A-H pyeloplasty with or without D-J stent in patients of unilateral hydronephrosis. Post operatively renal function was estimated after 3 months by DTPA renogram. Methods: It was a prospective study at Paediatric Surgery department of Bangabandhu Sheikh Mujib Medical University from April 2009 to October 2010. Twenty eight ( age, sex, side and type of operation matched) patients of unilateral hydronephrosis were included in the study and divided into two Groups: Group A (na =15) and Group B (nb=13) patients who underwent A-H pyeloplasty with D-J stent and A-H pyeloplasty with nephrostomy tube respectively. Child with bilateral hydronephrosis, hydronephrosis with associated anomalies like horseshoe kidney, ectopic kidney, solitary kidney, hydronephrosis with vesico ureteric reflux and redopyeloplasty were excluded in this study. Unpaired “t” test and Chi-square test were used for statistical analysis whereas postoperative hospital stay and renal functional improvement were used as parameters of the study. Results: For study Group A (A-H pyeloplasty with D-J stent) postoperative hospital stay were significantly lesser (P&lt;0.00) than the GroupB ( A-H pyeloplasty with nephrostomy tube). Post operative split renal function and glomerular filtration rate (GFR) in Group A was improved (percentage) than Group B. Conclusion: This study reveals postoperative shorter hospital stay and improved postoperative split renal function in A-H pyeloplasty with D-J stent. DOI: http://dx.doi.org/10.3329/jpsb.v2i1.15159 Journal of Paediatric Surgeons of Bangladesh (2011) Vol. 2 (1): 22-25

The results of dismembered flap pyeloplasty for hydronephrosis in children

Aim. To evaluate the effectiveness of dismembered flap pyeloplasty for extensive obstruction of the pyeloureteral segment in children. Methods. Dismembered flap pyeloplasty throughout the period 2001-2010 was performed in 9 children (first group), mean age 69 months, 7 (77.8%) boys and 2 (22.2%) girls. Left-sided hydronephrosis was diagnosed in 8 (88.9%) cases, right-sided hydronephrosis - in 1 (11.1%) case. Dismembered flap pyeloplasty was performed in those cases, when after the resection of the ureter and during an attempt to form a direct uretero-pyelo-anastomosis excessive tension of the tissues occurred. In order to replace the resected part of the ureter used was a tubularized U-shaped flap of the renal pelvis, which was anastomosed in an «end to end» fashion with the proximal section of the ureter. The comparison group (second group, 58 patients) included patients who had undergone dismembered pyeloplasty with the formation of uretero-pyelo-anastomosis in the horizontal plane after standard resection of the dysplastic area of the proximal ureter. Results. In the early postoperative period, clinical manifestations of urinary tract infections were recorded in 1 (11.1%) of 9 patients, treated medically. The degree and rate of reduction of the increased anteroposterior size of the renal pelvis after dismembered flap pyeloplasty significantly lagged behind the comparable parameters of patients undergoing standard dismembered pyeloplasty, and at the same time, one year after the operation noted was a marked decrease in the anteroposterior size of the renal pelvis by almost 3 times as compared to the preoperative values. Conclusion. Implementation of dismembered flap pyeloplasty for extensive ureter obstruction makes it possible to achieve good short- and long-term results in the treatment of hydronephrosis in children.

Comparative evaluation of the resolution of hydronephrosis in children who underwent open and robotic-assisted laparoscopic pyeloplasty

ObjectivesTo assess long-term postoperative ultrasonographic outcomes of robotic-assisted laparoscopic pyeloplasty (RALP) and of conventional open pyeloplasty (COP) in pediatric patients with ureteropelvic junction obstruction. MethodsRetrospective review of 312 patients who underwent RALP or COP in a single institution. Preoperative and postoperative ultrasounds were used to determine the grade of hydronephrosis. Postoperative assessment included 3 ultrasounds at 0–6, 6–12 and >12 months intervals. Patients were matched by age, etiology of obstruction, grade of preoperative hydronephrosis and gender for case-matched analysis. ResultsWe identified 212 pyeloplasties that met inclusion criteria, being 58 RALP and 154 COP. Groups were different in age, gender and etiology, but similar in severity of hydronephrosis and follow-up time. At the end of follow-up, complete resolution and success rates were 62% and 74% in RALP and 45% and 70% in COP, respectively. Matching included 105 patients. Complete resolution was higher in RALP (p = 0.004), while median time before improvement was lower (12.3 months RALP vs 29.9 months COP). There was no difference in success rate at the end of follow-up between the groups. ConclusionRALP shows satisfactory long-term outcomes, comparable to COP. In our cohort, patients who underwent robotic pyeloplasty showed faster resolution of hydronephrosis on ultrasound.

Hydronephrosis following ureteral reimplantation: When is it concerning?

ObjectivesHydronephrosis without obstruction is common prior to ureteral reimplant, especially in patients with high-grade VUR. Consequently, when hydronephrosis is present post-operatively, it is unclear when it should be concerning. We evaluated the finding of hydronephrosis in children undergoing reimplantation and its evolution following surgery. MethodsAfter obtaining IRB approval, we identified 938 children who underwent reimplantation at our institution from 1998 to 2006. Their pre- and post-operative US and clinical course were analyzed. ResultsHydronephrosis was observed in 24% pre-operatively and 21% post-operatively. 52% with pre-operative hydronephrosis had it post-operatively, while 12% without pre-operative hydronephrosis had it post-operatively. 71% of post-operative hydronephrosis resolved on average in 1.36 years. 19% didn’t resolve and 0.1% had ureteral obstruction. Risk factors for post-operative hydronephrosis included increasing severity of VUR, and high degree of pre-operative hydronephrosis. ConclusionHydronephrosis following ureteral reimplantation is not rare, and correlated to pre-operative evaluations. Post-operative hydronephrosis is frequently transient and benign, and usually resolves within the first 2 years. These patients do not require follow-up ultrasounds or further imaging, and can be followed clinically. Patients with high-grade VUR and hydronephrosis pre-operatively, however, are at risk for developing worsened hydronephrosis and should be followed with a 3-month post-operative ultrasound.

Hydronephrosis in Children With Abdominal and Pelvic Neoplasms: Outcome and Survival Analysis of a Single Center Pediatric Oncology Series

We ascertained the incidence and outcome of hydronephrosis related to abdominal or pelvic neoplasms and survival in pediatric patients. We retrospectively reviewed our institutional oncology database between January 1995 and November 2009. We reviewed the charts of all children with intra-abdominal (nonrenal) and pelvic neoplasms. Of the 366 patients whose charts were reviewed 66 (18%) had hydronephrosis at some point during treatment, including 12 with hydronephrosis that was not caused by the neoplasm and 1 who was lost to followup, leaving 53 with malignant obstruction. Of the remaining patients hydronephrosis resolved in 34 (64%) with treatment for the primary neoplasm alone while in 19 (36%) hydronephrosis persisted after primary oncological treatment. Univariate analysis revealed that patients with persistent hydronephrosis (p = 0.025), those with urological intervention (p = 0.05) and those with high stage disease (p <0.001) had statistically significantly worse overall survival. On Cox multivariate analysis only disease stage remained statistically significant (p = 0.004). Analysis of this group revealed that pediatric nonrenal abdominal and pelvic tumors are associated with hydronephrosis in about 20% of cases. Approximately 60% of these cases resolved with treatment for the primary tumor alone while 13% required specific urological intervention for urinary tract involvement or compression. Patients with pediatric malignant ureteral obstruction had a 20% 5-year mortality rate. The main predictive factor was primary disease stage.

Altered Cytoskeletal Structure of Smooth Muscle Cells in Ureteropelvic Junction Obstruction

Ureteropelvic junction obstruction is one of the most common causes of hydronephrosis in children. A malfunction of smooth muscle cells is believed to be the underlying mechanism causing obstruction. We investigated the expression of some integrins, talin and β-dystroglycan, considered the main compound of smooth muscle cell cytoskeleton, and active caspase 3 at the level of the ureteropelvic junction obstruction. Specimens were obtained at pyeloplasty in 12 children with ureteropelvic junction obstruction. Six control specimens were obtained during organ explantation. Specimens were divided into renal pelvis, ureteropelvic junction and ureter below the obstruction. Western blot analysis of active caspase 3, and immunofluorescence and polymerase chain reaction analysis were performed for α7A, β1A, α7B and β1D integrins, talin and β-dystroglycan. Talin and β-dystroglycan were slightly impaired in ureteropelvic junction obstruction, while α7B and β1D integrins were severely reduced, and α7A, β1A and active caspase 3 were significantly enhanced compared to controls. We demonstrated activation of apoptosis and a critical alteration of cytoskeleton that might explain the altered function and the increased apoptosis in smooth muscle cells in ureteropelvic junction obstruction. The delayed rearrangement of the cytoskeleton of smooth muscle cells in ureteropelvic junction obstruction might be linked to a postnatal splicing from α7A and β1A to α7B and β1D integrins, respectively. This relationship could explain the common clinical scenario of spontaneous improvement of hydronephrosis in children with suspected ureteropelvic junction obstruction.

Laparoscopic vascular relocation: alternative treatment for renovascular hydronephrosis in children

The standard treatment for pelviureteric junction obstruction (PUJO) has been dismembered pyeloplasty. The open surgical, Hellström procedure in which crossing polar vessels are relocated, has been an option in adult urological practice. We present our experience with laparoscopic vascular relocation in children. Data were retrospectively gathered on all patients who underwent laparoscopic relocation of lower pole vessels (LRLPV) at our institution between July 2004 and March 2008. Follow-up ultrasounds and MAG3 were obtained. LRLPV was performed in 10 boys and 9 girls. Patients were between 5.8 and 15.25 years (median 9.9 years). They presented with recurrent abdominal pain (n = 17), urinary tract infections (n = 7) and haematuria (n = 3). On ultrasound, MAG3 and retrograde studies they had hydronephrosis, obstructed drainage and a normal calibre ureter with a sharp cut-off. They were further assessed at laparoscopy and were found to have aberrant lower pole crossing vessels. All underwent laparoscopic mobilization of the lower pole vessels from the region of the PUJ thereby freeing the junction and relocating them superiorly onto the anterior wall of the pelvis. The median operating time was 120 min (range 60-240 min). The median hospital stay was 2 days (range 1-3 days). They were followed up for a median period of 12 months (range 6-36 months). All patients have remained asymptomatic. Ultrasound done at 6 months showed decreased hydronephrosis. MAG3 study showed improved drainage in 17, while 1 had poor drainage. This patient remains symptom free and is under regular follow up. Laparoscopic vascular relocation is an unconventional technique in carefully selected patients with PUJO. It obviates disrupting an intrinsically normal PU junction and treats the cause rather than the effect. Our intermediate-term results are encouraging and further long-term assessment is needed.

Retrocaval ureter with stone in the retrocaval segment of the ureter

Retrocaval ureter is abnormal looping of the proximal ureter behind the inferior vena cava. The aberrant anatomy results in the compression of the ureter causing hydronephrosis. This is a very infrequent cause of hydronephrosis in children. Association of retrocaval ureter with a stone in the looping segment of the ureter is extremely rare. We report one such pediatric case which was diagnosed preoperatively with a review of pediatric-only cases reported in last 5 years.

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.

Causal link between neonatal hydronephrosis and later development of hypertension

1. Although congenital ureteral obstruction is a common disorder in infants, its pathophysiology remains poorly understood and its clinical management continues to be debated. During the past decade, the surgical management of non-symptomatic hydronephrosis in children has become more conservative, but the long-term physiological consequences of this new policy are unclear. 2. In experimental models with complete ureteral obstruction, tubular atrophy and interstitial inflammation occur rapidly. Although this type of obstruction is very rare in clinical practice, it is often referred to in clinical discussions. New studies, using a model with chronic partial ureteral obstruction, have demonstrated that hydronephrosis is associated with renal injuries and is causally related to hypertension. 3. The mechanisms underlying the development of hypertension in experimental hydronephrosis are complex and involve changes in both the renin-angiotensin system and renal sympathetic nerve activity. Furthermore, oxidative stress and nitric oxide deficiency in the diseased kidney, with consequent resetting of the tubuloglomerular feedback mechanism, appear to play a pivotal role in the development and maintenance of hyper-tension. 4. In view of the new knowledge regarding the long-term effects of partial ureteral obstruction, today's non-operative management of hydronephrosis should be reconsidered to prevent obstructive nephropathy and hypertension in later life.

Retrocaval ureter: a rare cause of hydronephrosis in children

Retrocaval ureter is a relatively rare developmental anomaly of the inferior vena cava. It commonly manifests in the third to fourth decade of life; however, pediatric reports of this condition are very rare. Individuals with this anomaly are symptomatic because of ureteric obstruction. All symptomatic patients need surgery where the ureter is divided and anastomosed anterior to inferior vena cava. We report our experience of a child who presented with flank pain and, on evaluation, were found to have right hydronephrosis. During surgery, retrocaval anomaly was noticed and appropriately dealt with.

Diagnostic accuracy of color Doppler sonographic study of the ureteric jets in evaluation of hydronephrosis

Objective Hydronephrosis (HN) and obstruction are closely associated, but upper urinary tract dilatation can occur without significant obstruction. Despite some pitfalls, conventional ultrasonography and diuretic renography (DR) are the main means of evaluation of HN in children. Recent reports have demonstrated color Doppler ultrasonography (CDUS) to reliably identify ureteric jets in the bladder. The aim of this study was to evaluate this method as a diagnostic tool to distinguish obstructive from non-obstructive dilatations of the upper tract. Methods We evaluated 51 patients (37 boys and 14 girls), aged 3 months to 14 years (median 4 years), who presented with unilateral grade III and IV hydronephrosis with suspicion of pyeloureteral junction obstruction. All patients underwent DR and evaluation of ureteric jets by transverse CDSG of the bladder within a maximum of 2 weeks. Obstruction was considered in the DR when the hydronephrotic unit showed a differential renal function of less than 40%, or when symptomatic intermittent renal colic was present in older children. The number of ureteric jets was counted over a 5-min period and the frequency calculated for each ureteral orifice. Relative jet frequency (RJF) was defined as frequency of the hydronephrotic side divided by total ureteric jet frequency. Receiver-operating characteristic (ROC) plots were constructed to determine the best cut-off for RJF, in order to identify renal units with obstructive hydronephrosis. Results Twenty-three (45.1%) hydronephrotic units were considered obstructed. The mean RJF differed between obstructive (0.09 ± 0.15) and non-obstructive hydronephrosis (0.42 ± 0.11) ( p < 0.001). ROC analysis revealed that RJF <0.25 was the best threshold, and correctly discriminated obstruction in 91.2% of the children with a sensitivity of 87% (95% CI 78.6–98.2%) and specificity of 96.4% (95% CI 87.8–99%). The positive likelihood ratio was 24.3 and the area under the ROC curve was 0.92 (95% CI 0.86–0.98). Conclusions RJF <25% was found to be a good indicator of obstruction in children with unilateral hydronephrosis. CDUS evaluation of ureteric jets is an easy and non-invasive method that can be used as an initial diagnostic tool, and in follow-up cases, to differentiate obstructed from non-obstructed hydronephrosis in the pediatric population.

1201: Accuracy of Relative Ureteral Jet Frequency in the Diagnostic of Obstructive Hydronephrosis in Children

You have accessJournal of UrologyPodium 35, Monday, May 21, 2007, 3:30 - 5:30 pm1 Apr 20071201: Accuracy of Relative Ureteral Jet Frequency in the Diagnostic of Obstructive Hydronephrosis in Children Jose Bessa-Junior, Francisco T. Denes, Cristina Chammas, Luciana Cerri, Edison D. Schneider-Monteiro, Giovanni G. Cerri, and Miguel Srougi Jose Bessa-JuniorJose Bessa-Junior More articles by this author , Francisco T. DenesFrancisco T. Denes More articles by this author , Cristina ChammasCristina Chammas More articles by this author , Luciana CerriLuciana Cerri More articles by this author , Edison D. Schneider-MonteiroEdison D. Schneider-Monteiro More articles by this author , Giovanni G. CerriGiovanni G. Cerri More articles by this author , and Miguel SrougiMiguel Srougi More articles by this author View All Author Informationhttps://doi.org/10.1016/S0022-5347(18)31415-0AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail "1201: Accuracy of Relative Ureteral Jet Frequency in the Diagnostic of Obstructive Hydronephrosis in Children." The Journal of Urology, 177(4S), p. 396 © 2016 by American Urological AssociationFiguresReferencesRelatedDetails Volume 177Issue 4SApril 2007Page: 396 Advertisement Copyright & Permissions© 2016 by American Urological AssociationMetricsAuthor Information Jose Bessa-Junior More articles by this author Francisco T. Denes More articles by this author Cristina Chammas More articles by this author Luciana Cerri More articles by this author Edison D. Schneider-Monteiro More articles by this author Giovanni G. Cerri More articles by this author Miguel Srougi More articles by this author Expand All Advertisement Loading ...

Ureteral polyps: an etiological factor of hydronephrosis in children that should not be ignored

To better define the demographics, urothelial distribution and typical gross anatomic and radiologic appearances of fibroepithelial polyps of the ureter in children. We reviewed 15 cases of fibroepithelial polyps of the ureter with hydronephrosis from the archives of our department. Data were collected from radiographic studies, gross anatomic pathology and pathology and radiology reports and categorized by age, sex, clinical presentation, lesion size and location. The mean patient age was 9.1 years, and 80% were male. All of them presented with hematuria and/or flank pain. The polyps were located in the upper ureter or ureteropelvic junction (UPJ) and pelvis. Of the polyps, 60% were multiple polyps or filiform, and 40% were single or bilobed and 1-6 cm in size. Only four cases showed typical filling defect on intravenous urography. In five cases, sonography showed a mildly echogenic structure extending into the ureter from the renal pelvis. Enhanced CT revealed soft tissue filling UPJ or/and proximal ureter in six cases, and hydroureter was found in one case by three-dimensional (3D) image. Fibroepithelial polyps were diagnosed in all cases by postoperative histological examination. Fibroepithelial polyps are the most common benign tumors of the ureter. Congenital factor may be associated with the origin of fibroepithelial polyps in children. The preoperative diagnosis of ureteral polyps is difficult. A history of flank pain, hematuria or both, other than abdominal mass, light-to-moderate hydronephrosis with soft-tissue in UPJ or upper ureter, shown by sonography and radiological examination, may help in the diagnosis of ureteral polyps in children. Ureteral polyps should be recognized as an important etiology for hydronephrosis in children.

Bilateral congenital midureteric stricture

Midureteric stricture is a rare cause of congenital hydronephrosis. Its etiology and pathophysiology is uncertain. We report a case of an 8 year old male child who presented with recurrent urinary tract infections and moderate renal impairment. Sonar revealed bilateral hydronephrosis. This was confirmed to be due to intrinsic midureteric narrowing on MRU. Bilateral ureteric exploration confirmed these findings and uretero-ureterostomy was performed. Postoperative imaging showed improvement in hydronephrosis. We review the published literature. CASE REPORT An 8 year old boy was admitted to our institution with a documented UTI. He had no significant past medical history. Physical examination was non-contributory. He was in moderate renal impairment with a serum Creatinine of 130mmol/l and an estimated Creatinine Clearance, using the Schwartz formula, of 50ml/min/m?. Urine cultures for Tuberculosis were negative. Renal sonar revealed gross bilateral hydroureteronephrosis with thin renal cortices. The bladder appeared normal. Of note no ureteric dilatation was seen at the level of the bladder. An MCUG revealed a normal bladder and posterior urethra with no reflux. Radioisotopic mercaptoacetyltriglycine (MAG3) renography showed poor uptake bilaterally with apparent holdup at the midureteric level. In view of the unusual imaging and to exclude extrinsic retroperitoneal pathology a Gadolinium enhanced magnetic resonance urogram was requested. This showed no retroperitoneal pathology, but bilateral midureteric obstruction. (See Figure 1). Figure 1 Figure 1: Gadolinium enhanced magnetic resonance urogram demonstating midureteric obstruction. Retrograde pyelograms revealed a tight, short-segment, nonnegotiable stricture at the level of the pelvic brim bilaterally. (Figure 2) Bilateral congenital midureteric stricture 2 of 3 Figure 2 Figure 2: Left retrograde pyelogram showed a pelvic brim stricture. Bilateral extraperitoneal ureteric exploration was performed using a Gibson incision. On both sides a similar appearance was seen. The stricture was excised revealing a pin-hole lumen. No valves or polyps were noted intraluminally. Stented ureter-ureterostomy was performed without tapering. The child made an uneventful recovery. Followup sonar at 3 months showed improvement in hydronephrosis bilaterally. Pathological review revealed proximal dilatation with nonspecific thickening of the muscular wall. Electron microscope evaluation of the strictured area showed no specific ultrastructural abnormality. DISCUSSION Congenital midureteric stricture is an uncommon cause of hydronephrosis in children. Less than 20 pathologically confirmed cases are reported in the literature. (2) The diagnosis may be confused with ureteropelvic or ureterovesical junction obstruction. Hence, retrograde pyelography is essential in the management of this anomaly. The differential diagnosis must additionally include ureteral valves and fibroepithelial polyps. Ectopic ureter and contralateral renal agenesis have been associated with some of the published cases. (2,4) The bilateral nature of our case would lend support to Kropp's assertion that contalateral agenesis and bilaterality point to the manifestation of a similar pathological process in this condition. (2) The cause of congenital midureteric stricture, however, remains unknown. Docimo postulated a variety of etiologic possibilities: 1) improper ureteric recanalisation, 2) insufficient vascular supply, 3) persistent ureteric folds, 4) ureteric bud anomalies. (3) It has been postulated that this condition runs a more aggressive natural history than other causes of congenital hydronephrosis. (2) This feature is born out by our case where longstanding obstruction resulted in renal impairment.

Calyceal Plication with Pyeloplasty in the Treatment of Giant Hydronephrosis in Children

The relief of obstruction alone is frequently not sufficient to ensure renal salvage in giant hydronephrosis. We report on our experience with plication of the renal calyces used as an adjunct to dismembered pyeloplasty in patients with giant hydronephrosis. We describe the operative technique and outcomes in ten children after a follow-up period of six months. Ten patients (six girls and four boys) with a mean age of 8.1 years (range 2-14 years) with giant hydronephrosis caused by primary ureteropelvic junction obstruction underwent a dismembered pyeloplasty followed by plication of the dilated renal calyces. The preoperative evaluation included an excretory urography, ultrasonography, 99mTc-DMSA and 99mTc-DTPA scans. The same tests were repeated six months after the operation to evaluate the outcomes. There were no intraoperative or postoperative complications. Excretory urography and ultrasonography performed six months after the operation demonstrated a significant improvement of the morphology of the operated kidneys. The kidneys shrunk in diameter from a mean of 149.5 mm (range 89-224 mm) to 93.6 mm (range 68-121 mm) and the mean diameter of the calyces was reduced from 26.9 mm (range 15-42 mm) to 14.7 mm (range 10-24 mm). Renal 99mTc-DTPA scans showed improved perfusion and renal function after surgery, with the mean elimination rate decreasing from 22.41 min (range 17.84 - 28.22 min) to 11.7 min (range 8.16-13.76 mm). 99mTc-DMSA scans demonstrated no new scars and no deterioration of renal parenchyma after surgery. We believe that plication of the renal calyces is the method of choice to be used as an adjunct to the Anderson-Hynes pyeloplasty in the treatment of paediatric patients with giant hydronephrosis.