Neonatal management of unilateral hydronephrosis. Role for delayed intervention

Clearance While Upright on Initial Diuretic Renography Predicts the Need for Surgery in Children With Congenital Hydronephrosis

OBJECTIVE

To improve the predictive ability of diuretic renography (DR) for surgical intervention in children with congenital hydronephrosis (CH) and concern for ureteropelvic junction obstruction.

METHODS

Children with CH born between 2007 and 2021 who underwent initial DR prior to 6months of life, had both clearance while upright (CUP) and T ½ reported, and did not have immediate surgical intervention after the first DR were retrospectively evaluated for surgical intervention during the period of clinical observation. Once the optimal cut-points were identified for CUP and T ½, they were used to calculate the sensitivity, specificity, positive predictive value, and negative predictive value.

RESULTS

In total 65 patients were included in the final analysis with 33 (50.8%) undergoing surgical intervention (pyeloplasty) and 32 (49.2%) still on observation at last follow-up. The optimal cut-points for predicting surgical intervention were 28.1 minutes for T ½ and 22.4% for CUP. Applying the CUP cut-point of 22.4% we achieved a sensitivity of 60.6% (95% CI: 43.9-77.3), specificity of 96.9% (95% CI: 90.1-100.0), positive predictive value of 95.2% (95% CI: 86.1-100.0), and negative predictive value of 70.5% (95% CI: 57.0-83.9).

CONCLUSION

A low CUP accurately predicts surgical intervention in children with CH who are initially observed. Although there is no singular measure on DR that can with absolute certainty predict future clinical course, our data do suggest there is utility in incorporating CUP (if <22.4%) into the decision process. Further research is necessary to help guide the management of children with intermediate CUP values.

Pelvico-Vesicostomy for Horseshoe Kidney With Severe Right Ureteric Stricture and Bilateral Hydronephrosis

Ureteropelvic junction (UPJ) obstruction is the most common renal anomaly observed in infants with congenital hydronephrosis. The present study presents a five-month-old infant with severe right ureteropelvic obstruction. Anderson-Hynes pyeloplasty intervention significantly improved renal function. The study concludes that early surgical intervention is the definitive treatment for avoiding kidney impairment and its complications.

Evaluation of transverse dorsal lumbotomy in management of PUJ obstruction in patients younger than 6 months

OBJECTIVE

The transverse dorsal lumbotomy approach provides excellent exposure to the PUJ and causes minimal tissue damage. In this study, we assess the efficacy of dorsal lumbotomy in PUJ obstruction in children younger than 6 months.

METHODS

All children less than 6 months who were managed with the dorsal lumbotomy approach between 2009 and 2017 were reviewed prospectively. Data included: demographic data, pre/post-operative renal ultrasound scan with SFU grading and RDS, operative time, post-operative complications, and follow up results.

RESULTS

A total of 42 children with a mean age of 4.4 ± 1 months were included. On pre-operative RDS, all patients had an obstructive pattern and a SRF of 30.3 ± 9.3. The mean operative duration was 49 min and analgesia was minimal. Post-operative ultrasound at 6 months showed an improvement in hydronephrosis (p < 0.05) and a mean SRF of 39.3 ± 6.1 (p < 0.001).

CONCLUSION

Transverse dorsal lumbotomy approach is a safe and efficient alternative in patients less than 6 month.

Ultrasound-Based Scoring System for Indication of Pyeloplasty in Patients With UPJO-Like Hydronephrosis

Background: Previous scoring systems have used renal scan parameters to assess severity of ureteropelvic junction obstruction-like hydronephrosis (UPJO-like HN), however this information is not always reliable due to protocol variation across centers and renogram limitations. Therefore, we sought to evaluate the Pyeloplasty Prediction Score (PPS), which utilizes only baseline ultrasound measurements to predict the likelihood of pyeloplasty in infants with UPJO-like. Methods: PPS was developed using three ultrasound parameters, Society of Fetal Urology (SFU) grade, transverse anteroposterior (APD), and the absolute percentage difference of ipsilateral and contralateral renal lengths at baseline. PPS was evaluated using prospectively collected prenatal hydronephrosis data (n = 928) of patients with UPJO-HN. Children with vesicoureteral reflux. primary megaureter, other associated anomalies, bilateral HN and <3 months of follow-up were excluded. Scores were analyzed regarding its usefulness in predicting which patients would be more likely to undergo pyeloplasty. Sensitivity, specificity, likelihood ratios (LR) and receiver operating characteristic (ROC) curve were determined. Results: Of 353 patients, 275 (78%) were male, 268 (76%) had left UPJO-like HN, and 81 (23%) had a pyeloplasty. The median age at baseline was 3 months (IQR 1-5). The PPS system was highly accurate in distinguishing patients who underwent pyeloplasty using baseline ultrasound measurements (AUC: 0.902). PPS of 7 and 8 were found to have a sensitivity of 85 and 78%, and specificity of 81 and 90%, respectively. PPS of 8 was associated with a LR of 7.8, indicating that these patients were eight times more likely to undergo pyeloplasty. Conclusion: Overall, PPS could detect patients more likely to undergo pyeloplasty using baseline ultrasound measurements. Those with a PPS of eight or higher were eight times more likely to undergo pyeloplasty.

A long-term follow-up in conservative management of unilateral ureteropelvic junction obstruction with poor drainage and good renal function

The aim of the study was to retrospectively review the outcome of neonatal ureteropelvic junction obstruction with a good renal function and a poor drainage at a first diuretic renal scan, in cases where surgery was recommended on the basis of a loss of renal function, worsening of hydronephrosis or occurrence of clinical symptoms. Hydronephrosis was graded from 1 to 4 or as ureteral tract dilatation (UTD) P1 to UTD P3. During follow-up, 15 out of 38 patients (34.2%) required surgery while 25 out of 38 (65.8%) could have been managed conservatively. In patients with grade 2, 3, and 4 hydronephrosis, the ureteropelvic junction obstruction resolved or improved spontaneously in 100%, 63%, and 33% of cases (in 100% of UTD P1, 67% of UTD P2, and 50% of UTD P3), respectively. The median of follow-up was 14 years. Chi-square test showed a significant relationship between initial grade of hydronephrosis or UTD and the possibility of an efficient conservative management (p = 0.0088 and p = 0.0460).Conclusion: Conservative management can be safely achieved in ureteropelvic junction obstruction with poor drainage. Scheduled controls are needed for early discovery of functional renal deterioration. High-grade hydronephrosis is unlikely to resolve spontaneously and is often accompanied by a loss of renal function during the first years of life. What is Known: • There is controversy about which management should be adopted in infants with unilateral ureteropelvic junction obstruction with poor drainage but good differential renal function. What is New: • Long-term follow-up suggests that conservative management can be safely achieved also in unilateral ureteropelvic junction obstruction with poor drainage in more than 60% of cases, even if high-grade hydronephrosis is unlikely to resolve spontaneously and it is often accompanied by a loss of renal function during the first years of life. In our experience, surgical intervention was required in more than 50% of cases before 1 year of life and in all cases before 3 years of life.

Anderson-Hynes pyeloplasty in children - long-term outcomes, how long follow up is necessary?

Introduction

Pyeloplasty is commonly conducted in children with uretero-pelvic junction obstruction. Standard post-operational procedure involves only a short period of time after the surgery. What is the real number of complications, including those in the long-term? What is the function of the operated kidney?

The aims of this study are to assess the effectiveness of pyeloplasty and to assess the suitability of conducting long term follow-up after pyeloplasty.

Material and methods

35 of 137 patients after open pyeloplasty between 1992–2006 responded to the invitation and returned for a control appointment. The median age was 8 years (range 1 month – 19 years). In 26 kidney units the disease proceeded with symptoms and in 10 cases it proceeded without symptoms. The predominant symptom was abdominal pain (n = 21). In each child both the control ultrasound and the diuretic renal scintigraphy of the kidneys were conducted.

Results

Regression of symptoms after the operation was obtained in 19 kidney units (73%). Improvement in scintigraphy was observed in 23 kidney units (82.1%), improvement in ultrasound was obtained in 32 (91%) kidney units. Complications which required surgical intervention occurred in 4 (11.1%) patients. One patient required operative removal of a pyelostomy tube, 2 patients (11.1%) required repeated pyleoplasty (23 and 27 months after the operation), one child required nephrectomy due to nephrogenic arterial hypertension (after 4 years).

Conclusions

Statistically, there are improvements of scintigraphic function of the kidney, improvements in ultrasound examinations, and the remission of symptoms after pyeoplasty. Most complications occur within 2 years after the surgery. Long-term follow up should be continued.

Predictors of Renal Functional Improvement After Pyeloplasty in Ureteropelvic Junction Obstruction: Clinical Value of Visually Assessed Renal Tissue Tracer Transit in 99mTc-mercaptoacetyltriglycine Renography

OBJECTIVE

To determine the clinical value of visually assessed renal tissue transit time (TTT) in ^99mTc-mercaptoacetyltriglycine (^99mTc-MAG3) renography for patients undergoing pyeloplasty.

MATERIALS AND METHODS

Medical records of 164 patients who underwent dismembered pyeloplasty were retrospectively reviewed. Baseline and postoperative renal ultrasonography and ^99mTc-MAG3 renography were performed. Two urologists blinded to clinical data evaluated the renography and classified TTT as timely or delayed based on visualization of the tracer in the kidney pelvis between 2 and 10 minutes. Renal functional change after pyeloplasty was compared between patients in the timely and delayed groups.

RESULTS

A total of 126 patients (median age, 9 months) were evaluated after excluding patients with bilateral ureteropelvic junction obstruction, a single functioning kidney, duplicated ureter, or <3 months of follow-up. There were no differences between 89 patients with timely TTT and 37 patients with delayed TTT in mean preoperative hydronephrosis grade (3.7 vs 3.8) and pelvic diameter (3.1 cm vs 3.4 cm). Although the pre- and postoperative mean values of differential renal function (DRF) were significantly higher in the timely group than in the delayed group (47.2% vs 38.3% and 47.9% vs 44.6%), DRF change was greater in the delayed group (6.3% vs 0.6%). In multivariate analysis, delayed TTT was the only significant predictor of >5% improvement in renal function after pyeloplasty.

CONCLUSION

Delayed TTT in ^99mTc-MAG3 renography was a significant predictor of renal functional improvement after pyeloplasty in ureteropelvic junction obstruction. Because substantial improvement of renal function is anticipated, we recommend immediate pyeloplasty in patients with delayed TTT and decreased DRF.

Therapeutic approaches and long-term follow-up for prenatal hydronephrosis

Objective:

This study summarises the outcomes of 149 patients who underwent surgery for antenatally diagnosed unilateral hydronephrosis.

Methods:

The medical records of such patients over a 23-year period were reviewed retrospectively. Age at the time of operation, preoperative and postoperative mean pelvic diameter on ultrasound, split renal function, washout patterns on scintigraphy, and early and late complications were recorded.

Results:

The mean preoperative follow-up period was five months (range: 1–66 months). One patient was operated on after 12 months and two patients after five years of follow-up. Mean preoperative pelvic diameter and renal function were 30.8 mm and 38.6%, respectively; all patients had an obstructive wash-out pattern. In the postoperative period, the corresponding measurements were 11.7 mm and 39.2%, with 111 non-obstructive, 24 partially obstructive, and 14 obstructive wash-out patterns. Three patients with severe caliectasis and low renal function underwent surgery despite mild hydronephrosis. The mean postoperative follow-up period was six (range 4–11) years. Complications developed in 14 (9.3%) patients.

Conclusion:

Patients with antenatal hydronephrosis may need surgery even after a follow-up period of six years. Because of the potential late development of complications, postoperative follow-up should be continued for 10 years.

Hydronephrosis after retroperitoneal laparoscopic dismembered Anderson-Hynes pyeloplasty in adult patients with ureteropelvic junction obstruction: A longitudinal analysis

Objective

We evaluated the improvement of hydronephrosis longitudinally after laparoscopic dismembered Anderson–Hynes pyeloplasty in adult patients with ureteropelvic junction obstruction.

Material and methods

Sixteen patients underwent laparoscopic pyeloplasty at our institution between January 2006 and June 2012. Hydronephrosis was assessed by ultrasound and intravenous pyelography at 3, 6, 12, 18, and 24 months after pyeloplasty.

Results

The mean follow–up time was 24 months. Preoperative hydronephrosis was diagnosed as grade 2 and grade 3 in 8 patients each. Postoperative improvement of the hydronephrosis by one grade was observed in 56%, 73%, 67%, 50%, and 40% of patients at 3, 6, 12, 18, and 24 months, respectively. Improvement of the hydronephrosis by two grades was observed in 6%, 27%, 33%, 50%, and 60% of patients at 3, 6, 12, 18, and 24 months, respectively. In 5 of 12 patients (42%), hydronephrosis was still improving even after 12 months postoperatively.

Conclusions

Adult patients demonstrate relatively rapid improvements in the degree of hydronephrosis after laparoscopic pyeloplasty and continue to improve for a long time.

Trends in the Rates of Pediatric Pyeloplasty for Ureteropelvic Junction Obstruction over 19 Years: A PHIS Database Study

Background. Over the past 20 years, the management of ureteropelvic junction obstruction (UPJ) has shifted. While many urologists note a decrease in the number of pyeloplasties performed over time, the nature of the change in practice has yet to be defined. In the current study, we utilize a national, multi-institutional database of children's hospitals to evaluate trends in patients undergoing pyeloplasty as well as the rate of surgical reconstruction over the past 20 years. Material/Methods. We queried the Pediatric Health Information System (PHIS) database for all children undergoing primary pyeloplasty between 1992 and 2011. Clinical variables, including age at time of surgery, gender, length of stay (LOS), and geographic region, were determined. Age-adjusted rate of repair was also calculated per 100,000 PHIS inpatients. Results. 6,013 patients were included in the study, of which 71.6% were male and 64.2% were under the age of 24 months at time of surgery. Over the study period, the median age at time of surgery increased from 2-4 months to 12-14 months (P < 0.01). LOS decreased from a median of 5 days to 2 days (P < 0.001). The rate of surgery increased by 10.6 pyeloplasties per 100,000 PHIS inpatients from 1992 to 2011 (P < 0.01). The highest rate of pyeloplasty was in the northeast. The increase in pyeloplasties performed from 1992 to 1999 was specific to children aged greater than 24 months, while rates stayed the same in infants younger than 2 years during the same time period. In contrast, from 1999 to 2011, the rate of pyeloplasty decreased in patients less than 2 years of age, while the rate remained constant in patients over age 2. Conclusion. The rate of pyeloplasty increased in PHIS hospitals from 1992 to 2011. Trends are due to an increase in surgery in infants younger than 2 years from 1992 to 1999, followed by a progressive surgical rate decline, characterized by a shift towards patients older than 2 years of age.

[Childhood ureteropelvic junction obstruction in a regional treatment center: spectrum and therapy]

BACKGROUND

Ureteropelvic junction obstruction is the most frequent malformation of the upper urinary tract and treatment with conservative or operative management remains controversial. In this study we present the retrospective analysis of 129 children with ureteropelvic junction obstruction who underwent conservative or operative management.

MATERIAL AND METHODS

A total of 129 children with ureteropelvic junction obstruction, who were treated in the department of pediatric nephrology at the University of Essen from 1998-2005, were included into the analysis. Clinical charts were reviewed for the parameters urinary tract infections (total number, severity, bacteriology), antibiotics, ultrasound, Tc-99 diuresis renography, and management (conservative or operative). Statistical analysis was performed using the SPSS software (Version 11.0) RESULTS: A total of 89 urinary tract infections was observed in 52 children. The mean width of renal pelvis was 3.04 ± 1.33 cm in the operative group and 1.98 ± 1.2 cm in the conservative group (p=0.001, ANOVA test). Tc-99 diuresis renography was performed in 70 children of which 46 children received primarily conservative management and 24 children were operated. In the conservative group 6 children underwent pyeloplasty later on due to aggravation of renal function. In 59 out of 129 cases diuresis nephrography was not performed due to only mild ectasia.

CONCLUSIONS

This study demonstrates that conservative management is safe in children with ureteropelvic junction obstruction with no or only little constricted renal function, if a close-meshed surveillance protocol is followed and parental compliance is given.

Mild to moderate postnatal hydronephrosis--grading systems and management

No universal guidelines exist for the management of patients with mild to moderate antenatal hydronephrosis (ANH). Unsurprisingly, practice patterns vary considerably with respect to recommendations for postnatal evaluation and follow-up imaging schedule. Although some clinical tools are available to specifically grade ANH and postnatal hydronephrosis, these are commonly used interchangeably with varying degrees of success. A universal classification system and nomenclature are needed to best identify patients at risk of renal deterioration, UTI and need for surgical intervention. We present our own approach to postnatal risk stratification and management, including recommendations regarding serial ultrasonography schedule, prophylactic antibiotics, voiding cystourethrogram and renal scintigraphy.

Hydronephrosis due to pelviureteric junction narrowing: Utility of urinary enzymes to predict the need for surgical management and follow-up

AIM

To study the role of urinary enzymes N-acetyl-β-glucosaminidase (NAG), alkaline phosphatase (AKP) and gamma glutamyl transferase (GGT) in the diagnosis and follow-up of patients with suspected pelviureteric junction obstruction (PUJO).

MATERIALS AND METHODS

A total of 70 patients, 29 managed conservatively (group A) and 41 managed by pyeloplasty (group B), were studied prospectively. A serial measurement of urinary enzymes NAG, AKP and GGT level was performed in both the groups. The mean levels of these urinary enzymes were compared between the two groups and among the patients of the same group at presentation as well as during follow-up.

RESULTS

There was a significant fall in the mean AKP level in patients managed conservatively at 8 months of follow-up. Similarly, in the operated group, there was a significant fall in the AKP levels at both 3 months and 8 months of follow-up. The mean level of GGT also showed a significant fall after 3 months of surgery but did not show further significant change at 8 months after surgery. The mean levels of NAG and GGT in the conservatively managed group were significantly low compared with that of patients requiring pyeloplasty at presentation as well as in the follow-up. The mean level of AKP was significantly low in the conservatively managed group when compared with the patients requiring surgery, but did not differ significantly in both the follow-ups after surgery.

CONCLUSIONS

The level of urinary enzymes NAG, AKP and GGT are significantly high in the patients with hydronephrosis (HDN) requiring pyeloplasty when compared with the patients managed conservatively. The level of AKP significantly falls after pyeloplasty in the patients of HDN due to PUJO. There is a negative correlation with the preoperative level of enzyme NAG with split renal function in the patients of HDN requiring pyeloplasty.

Role of urinary biomarkers in the diagnosis of congenital upper urinary tract obstruction

Background:

Congenital obstructive uropathy constitutes a significant cause of morbidity in children. Currently, there is no reference standard for the diagnosis of renal obstruction in children. The noninvasive measurement of biomarkers in voided urine has considerable appeal as a potential application in children with congenital obstructive nephropathy. The aim of the present review is to explore the current role of biomarkers in the diagnosis and follow-up of obstructive uropathy in children.

Materials and Methods:

The literature database (PubMed) was searched from inception to May 2007 regarding the role of urinary biomarkers in the diagnosis and follow-up of children with congenital obstructive uropathy.

Results:

The review included 23 experimental and 33 prospective controlled clinical studies. Several cytokines, peptides, enzymes and microproteins were identified as major contributors to or ensuing from obstruction-induced renal fibrosis and apoptosis. The most important biomarkers were transforming growth factor-β₁ (TGFβ₁), epidermal growth factor (EGF), endothelin-1 (ET-1), urinary tubular enzymes [N-acetyl-β-D-glucosaminidase (NAG), γ-glutamyl transferase (GGT) and alkaline phosphatase (ALP)], and microproteins [β₂-microglobulin (β₂M), microalbumin (M. Alb) and micrototal protein (M.TP)]. All biomarkers showed different degrees of success but the most promising markers were TGFβ₁, ET-1 and a panel of tubular enzymes. These biomarkers showed sensitivity of 74.3% to 100%, specificity of 80% to 90% and overall accuracy of 81.5% to 94% in the diagnosis of congenital obstructive uropathy in children. Moreover, some of the markers were valuable in differentiation between dilated non-obstructed kidneys in need of conservative management and obstructed kidneys in need of surgical correction. Some studies demonstrated that urinary biomarkers are helpful in the evaluation of success of treatment of children with congenital renal obstruction. Some limitations of the previous studies include lack of different types of controls and small sample size. Larger studies with variable controls are invited to confirm the clinical usefulness of biomarkers in the diagnosis and follow-up of children with congenital obstructive uropathy.

Conclusion:

Urinary biomarkers are a promising tool that could be used as a noninvasive assessment of congenital renal obstruction in children.

Long-term follow-up and management of prenatally detected, isolated hydronephrosis

PURPOSE

The aim of the study was to determine the outcome and management of infants with isolated hydronephrosis, detected prenatally and confirmed postnatally.

MATERIALS AND METHODS

Between January 1988 and January 2008, the files of 629 children (492 males and 137 females), who were diagnosed prenatally with isolated, unilateral hydronephrosis, and the diagnosis was confirmed postnatally, were retrospectively reviewed. The median follow-up time was 142 months. Serial ultrasonography and isotope diuretic renography nuclear imaging were performed. Hydronephrosis was assessed and classified according to the Society of Fetal Urology (SFU) grading system.

RESULTS

Initially, all of the children were treated conservatively. Stabilization occurred in all children with grade 1 hydronephrosis, in 87% of children (144) with grade 2 hydronephrosis, and in 30% of children (37) with grade 3 hydronephrosis. However, 13% of children (21) with grade 2 hydronephrosis, 70% of children (85) with grade 3 hydronephrosis, and 100% of children with grade 4 hydronephrosis received surgical intervention according to our predetermined criteria. Ninety-five patients (late pyeloplasty group) were treated for a reduction for a differential renal function (DRF) to less than 40%, and 80 children (early pyeloplasty group) underwent surgery for a DRF more than 40%, but hydronephrosis progressed to higher grades or failed to improve and had poor radiotracer clearance. Significant improvements after pyeloplasty were noted in both groups with respect to the DRF and the ratio of the depth of the calyces to the thickness of the parenchyma (C/P ratio; P < .0001). The improvement in DRF was greater in the late pyeloplasty group than the early pyeloplasty group (P = .044), whereas the improvement in the C/P ratio was greater in the early pyeloplasty group than the late pyeloplasty group (P = .001). The ipsilateral DRF was preserved in the early pyeloplasty group, whereas the ipsilateral DRF was still less than 40% in the late pyeloplasty group. The improvement in DRF was significant during the first year postoperatively and became stable thereafter. The C/P ratio was inversely correlated with the DRF in the patients before and after pyeloplasty (r = -0.257; P = .01; and r = -0.616; P = .001, respectively).

CONCLUSIONS

All infants with SFU-1 and most infants with SFU-2 hydronephrosis have relatively benign conditions and do not need an invasive procedure. Although greater improvement occurred in patients with an initial DRF less than 40%, the reduced DRF did not recover to the predeterioration level postoperatively. Earlier surgical intervention after a short period of strict clinical surveillance is beneficial for preserving renal function for patients with persistent SFU-3 or SFU-4 hydronephrosis.

Modified Differential Renal Function Measurement Revised by Renal Cross Sectional Area in Children with Ureteropelvic Junction Obstruction

Purpose

Diuretic ^99mTc-diethylenetriaminepentaacetic acid (Tc-DTPA) renal scans may show false-negative or false-positive results in children with ureteropelvic junction obstruction (UPJO). We evaluated whether modified differential renal function (DRF) revised by the renal cross-sectional area on imaging study may be a more valuable predictor than conventional DRF on a renal scan for deciding on a proper interventional time.

Materials and Methods

Between September 2001 and January 2008, we reviewed the diuretic renal scan results of 29 pediatric patients who underwent pyeloplasty due to unilateral UPJO. Diuretic renal scans using the standard ^99mTc-DTPA protocol and imaging studies for renal unit measurement area were done. Conventional DRF measurement and modified calculation of DRF per unit area were done. Conventional DRF was classified into group I (below 40%) and group II (above 40%).

Results

The mean age of all patients was 42.6±52.6 months (range, 3-198 months). The mean cross-sectional areas of the UPJO kidney and of the normal contralateral kidney were 62.1±29.2 cm² and 41.3±22.5 cm², respectively (p<0.01). The conventional and modified DRF of the UPJO kidney were 45.2±9.2% and 35.2±9.5%, respectively (p<0.01). Thirteen children (62%) in group II (n=21) were classified in group I by the modified DRF measurement.

Conclusions

The modified DRF measurement calculated according to cross-sectional area showed fewer false-negative results and may be a valuable method for deciding on pyeloplasty under equivocal circumstances.

[Postnatally hydronephrosis (HN) in children with antenatally diagnosed hydronephrosis: surgery or medical treatment?]

OBJECTIVES

There is no formal agreement or criteria utilized to establish a standard of treatment in children with antenatally diagnosed HN.

METHODS

We analyzed our own experience in addition to the protocols attending to this subject. Twenty eight (28) children with unilateral HN were assessed from October 1999 through October 2005 and the anteroposterior diameter of renal pelvis (APDP) was measured.

RESULTS

Patients underwent surveillance with US and cintilography in 3, 6, 12 and 24 months. The treatment results were reviewed following the classification of Society of Fetal Urology: slight (2 to 5 mm), moderate (6 to 10 mm) and severe (> 10-15 mm).

CONCLUSIONS

We concluded that slight HN would never be operated on while the severe ones would always be. The moderate HN, on the other hand, would remain under surveillance with US and cintilography for two years.

Results of a practical protocol for management of prenatally detected hydronephrosis due to ureteropelvic junction obstruction

INTRODUCTION

Several algorithms exist for the management of prenatally diagnosed hydronephrosis due to ureteropelvic junction obstruction (UPJO). We utilize a conservative and practical approach emphasizing observation, with less frequent use of renal flow scans (RFS). We reviewed the results of 143 pediatric patients with congenital UPJO managed at our institution, focusing on surveillance and selective utilization of RFS, according to a standardized protocol.

MATERIALS AND METHODS

Charts of all infants with prenatally detected UPJO treated surgically or followed conservatively according to our protocol were reviewed. Patients were initially evaluated with ultrasound (US), voiding cystourethrogram, and RFS. Successive follow-up was with interval US. RFS was reserved for those with worsening hydronephrosis or that which failed to improve on US by 1 year. Radiographic studies and operative reports were examined. Gender, side of UPJO, degree of hydronephrosis, mode of management, and current status of the patients were noted.

RESULTS

The records of 143 patients and a total of 198 renal units (RU) were reviewed. The male:female ratio was 2.7. UPJO was unilateral in 88 (61%) patients and occurred more frequently on the left side (68%). Obstruction was bilateral in 55 (39%) patients. Initial US grade of hydronephrosis was Grade 1 in 56 RU (28%), Grade 2 in 51 RU (26%), Grade 3 in 50 RU (25%) and Grade 4 in 41 RU (21%). 178 RU (90%) were followed conservatively, while open dismembered pyeloplasty was the initial therapeutic approach in 20 RU (10%). The mean age at the time of surgery was 15.95+/-14.60 weeks (range 2-60). Indications included low differential renal function (DRF) (n=12), absence of tracer clearance from the renal pelvis (n=2), parental preference (n=3), and acute renal failure (n=3). Postoperative course was uneventful during 33.43+/-33.53 months (range 2-120) with favorable US and RFS results. In conservatively managed patients, mean follow-up time was 14.94+/-14.35 months (range 1.5-142). Spontaneous resolution of hydronephrosis was observed in 87 RU (49%), while 10 RU (5.6%) eventually required surgery for worsening appearance or function on US or RFS, respectively (n=8), symptom development (n=3), and/or parental preference due to persistently prolonged T1/2 (n=4). Seventy-two RU (40.4%) remain under surveillance with improvement (47.2%) or stable hydronephrosis (47.2%) in 94.4%. Decreased DRF occurred in 1 RU. Nine RU (5%) were lost to follow-up. With application of this algorithm, only 12% of patients underwent two or more RFS.

CONCLUSION

Pyeloplasty may be performed safely in infants when indicated; however, the majority of children with UPJO can be managed conservatively. Spontaneous resolution of hydronephrosis and/or favorable prognosis was encountered in 87% of conservatively managed RU. The use of a standard US grading system, selective utilization of follow-up renal function testing, and parental compliance are important factors in successful management.

Prenatally detected ureteropelvic junction obstruction: clinical features and associated urologic abnormalities

Urologic congenital anomalies associated with ureteropelvic obstruction (UPJO) have been previously characterized; however, less data are available regarding these associations in a prenatally diagnosed population. A retrospective study was conducted to evaluate significant clinical features and urological anomalies associated with prenatally diagnosed UPJO. The records of 143 children with prenatally diagnosed hydronephrosis secondary to UPJO were retrospectively reviewed. The gender, side of obstruction, degree of hydronephrosis, associated clinical features, and urological anomalies were noted. Hundred and forty-three children (M/F = 2.7) with a total of 198 affected renal units (RU) presenting with unilateral (61%) or bilateral (39%) UPJO were enrolled. In cases of unilateral obstruction, the left side was affected in 60 children (68%). The grade of hydronephrosis was Grade 1 in 56 RU (28%), Grade 2 in 51 RU (26%), Grade 3 in 50 RU (25%) and Grade 4 in 41 RU (21%). Associated clinical features included prematurity (n = 7, 4.9%), twinning (n = 5, 3.5%) and presentation with renal failure (RF) (n = 2). Excluding contralateral UPJO, other urologic anomalies were encountered in 29 patients (20.3%). Associated vesicoureteral reflux (VUR) was encountered in 11 patients (7.7%, M/F = 2.7). Pyeloplasty was required more often in children with associated VUR (54.5 vs. 18.2%) (P = 0.01). Contralateral multicystic dysplastic kidney (MCDK) was encountered in six patients (M/F = 2), one of whom presented with RF. One child carried the diagnosis of Schinzel-Giedion syndrome (SGS), demonstrating severe developmental and neurological disorders and bilateral hydronephrosis. The more frequent occurrence of UPJO in males with predominantly left-sided location, association with VUR and MCDK, and increased frequency of bilaterality in our prenatally diagnosed patients were similar to historical reports. In addition, prematurity and twinning were independently associated with UPJO. The higher rate of pyeloplasty in patients with associated reflux warrants further investigation.

Treatment and outcome of prenatally detected newborn hydronephrosis

OBJECTIVE

For neonates with antenatally diagnosed primary ureteropelvic junction (UPJ)-type hydronephrosis, to attempt to clarify and refine criteria for establishing optimal follow-up and treatment guidelines.

PATIENTS AND METHODS

A total of 162 newborns (228 hydronephrotic kidneys) with this condition were prospectively followed and treated by the same surgeon in 2001-2005 for a mean of 53 (13-72) months. Ultrasonography and diuretic renogram were used for diagnosis and follow up, and Onen's grading system to determine degree of hydronephrosis.

RESULTS

On first postnatal ultrasound, the severity of hydronephrosis was grade 1 in 152 kidneys (surgery, 0%), 2 in 41 (surgery, 19.5%), 3 in 19 (surgery, 42.1%), and 4 in 16 kidneys (surgery, 93.8%). All the grade 1 cases resolved spontaneously without renal deterioration (renal function >40%). Renal function ranged between 7% and 34% in grade 4 patients. Overall, 201 hydronephrotic kidneys (88.2%) resolved spontaneously, while 27 (11.8%) required pyeloplasty because of evidence of obstructive injury, including increased hydronephrosis in 14/27 (6/27 had less than 10% decrease in renal function), greater than 10% decrease of renal function in 9/27, and greater than 10% decrease of renal function as well as increased hydronephrosis in 4/27 patients (15%).

CONCLUSION

In most cases, neonatal hydronephrosis is a relatively benign condition that can be followed safely by an initial non-operative approach unless there is evidence of obstructive injury. A follow-up protocol that permits early identification of a limited number of kidneys that may develop signs of obstruction and require pyeloplasty is crucial for a favorable outcome in patients with primary UPJ-type hydronephrosis. Onen's hydronephrosis grading system promises an easier and more appropriate follow up and timely treatment for children with this condition. A sufficient follow-up interval, especially during the first 3 years of life, is essential to help prevent permanent loss of renal function in kidneys that do develop signs of obstruction.

A new modification of dismembered pyeloplasty for primary ureteropelvic junction obstruction

AIM

To present the results of a new modification of dismembered pyeloplasty performed to prevent the occurrence of secondary obstruction.

METHODS

Modified dismembered pyeloplasty was performed in 35 children (age range 3 months to 16 years) who had unilateral ureteropelvic junction obstruction. In postoperative follow-up, presence of hydronephrosis on ultrasonography, differential renal function (DRF) and renal drainage half-time on technetium-99m diethylenetriaminepentaacetic acid (DTPA) renography were recorded and compared with preoperative data.

RESULTS

Mean anteroposterior renal pelvic diameter, mean preoperative DRF and radioisotope clearance half-time on DTPA renography of the affected kidneys were 61.4 mm, 38.6% and 34.3 min in children with prenatal hydronephrosis, and 67.5 mm, 37.6% and 39.4 min in children that presented with symptoms, respectively. After surgery, mean anteroposterior renal pelvic diameter, mean DRF and radioisotope clearance half-time on DTPA renography of the affected kidneys were 10.9 mm, 45.9% and 11.9 min in children with prenatal hydronephrosis, and 20 mm, 41.9% and 15.2 min in children that presented with symptoms, respectively. No failure was observed in any patient at an average follow-up of 26 months (range 1-5 years).

CONCLUSIONS

Open dismembered pyeloplasty is the treatment of choice for intrinsic ureteropelvic junction obstruction. The modification of dismembered pyeloplasty that we performed is an alternative for the prevention of secondary obstruction.

Obstructed Versus Dilated Nonobstructed Kidneys in Children With Congenital Ureteropelvic Junction Narrowing: Role of Urinary Tubular Enzymes

PURPOSE

We evaluated the role of voided urine lysosomal enzyme N-acetyl-beta-D-glucosaminidase and brush border enzymes alkaline phosphatase and gamma-glutamyl transferase in differentiating between children with ureteropelvic junction obstruction in need of pyeloplasty and those with dilated nonobstructed kidneys suitable for conservative treatment.

MATERIALS AND METHODS

The study included 35 children with unilateral ureteropelvic junction obstruction treated with pyeloplasty (study group) and 15 children with dilated nonobstructed kidneys who were treated conservatively and followed for 15 months (control group). Voided urine samples were obtained before treatment from both groups, and from the study group at 1, 2, 3, 6, 9 and 12 months postoperatively and the control group at 3, 9 and 15 months of followup. N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase were measured in urine samples collected from both groups.

RESULTS

In the study group the activities of preoperative urinary N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase were significantly higher than in the control group. A cutoff value of 7.8 mU/mg creatinine N-acetyl-beta-D-glucosaminidase yielded a sensitivity of 97.1%, a specificity of 80% and an overall accuracy of 92%. A cutoff value of 34.5 IU/gm creatinine alkaline phosphatase resulted in a sensitivity of 91.4%, a specificity of 100% and an overall accuracy of 94%. A cutoff value of 54 IU/gm creatinine gamma-glutamyl transferase yielded a sensitivity of 62.9%, a specificity of 100% and an overall accuracy of 74%. The combination of urinary N-acetyl-beta-D-glucosaminidase and alkaline phosphatase resulted in a sensitivity of 100%, a specificity of 80% and an overall accuracy of 94%. Compared to preoperative activities, N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase decreased significantly at 12 months after pyeloplasty in the study group.

CONCLUSIONS

Voided urinary N-acetyl-beta-D-glucosaminidase, alkaline phosphatase and gamma-glutamyl transferase are accurate markers for differentiating between children with ureteropelvic junction obstruction requiring pyeloplasty and those with dilated nonobstructed kidneys suitable for conservative treatment. Measurement of these enzymes in voided urine could be used as a noninvasive tool for long-term followup of children with ureteropelvic junction obstruction after pyeloplasty and those receiving conservative treatment.

An alternative grading system to refine the criteria for severity of hydronephrosis and optimal treatment guidelines in neonates with primary UPJ-type hydronephrosis

OBJECTIVE

We present our alternative hydronephrosis grading system (AGS) in an attempt to establish optimal treatment guidelines, and clarify and refine the criteria for severity of hydronephrosis in neonates.

PATIENTS AND METHODS

A total of 162 newborns (228 affected kidneys) with antenatally diagnosed primary ureteropelvic junction-type hydronephrosis were prospectively followed and treated by the same surgeon for a mean of 46 (6-65) months. Ultrasonography and diuretic renogram were used for diagnosis and follow up. Society for Fetal Urology (SFU) grading system, anteroposterior diameter of renal pelvis (APDRP) and our AGS were used to determine the degree of hydronephrosis. AGS: 0, no hydronephrosis; 1, dilatation of renal pelvis alone; 2, plus caliceal dilatation; 3, plus <1/2 (mild-to-moderate) renal parenchymal loss; 4, plus >1/2 (severe) renal parenchymal loss (cyst-like kidney with no visually significant renal parenchyma).

RESULTS

On the first postnatal ultrasound, the severity of hydronephrosis was SFU< or =2 in 152 kidneys (surgery, 0%), SFU-3 in 41 kidneys (surgery, 19.5%) and SFU-4 in 35 kidneys (surgery, 68.6%). The follow up, treatment and outcome of SFU-1 and SFU-2 patients were similar; all resolved spontaneously without renal deterioration (renal function >40%). Renal function ranged between 7% and 39% in SFU-4 patients. Intrarenal pelvis was found in one patient with an APDRP of <15 mm, seven patients of 16-30 mm, and five patients of >30 mm. Overall, 201 hydronephrotic kidneys (88.2%) resolved spontaneously while 27 (11.8%) required pyeloplasty.

CONCLUSION

Neither an SFU grading system nor measurement of APDRP is the gold standard in determining the severity of hydronephrosis. Both methods may fail, particularly in children with intrarenal pelvis configuration or SFU-4 hydronephrosis. Our AGS promises easier follow up and more timely treatment.

[Prenatal diagnosis of hydronephrosis: utility of diuretic renography]

OBJECTIVE

To investigate the value of diuretic renography in patients with prenatally diagnosed unilateral hydronephrosis.

MATERIAL AND METHOD

We reviewed 44 patients who underwent ultrasonography in the first week of life and 1 month after birth, and cystography and diuretic renography at 1 month to evaluate differential renal function and the diuretic washout pattern. Patients with vesicoureteral reflux were followed-up according to the protocol for this disorder. In the remaining patients, ultrasonography and/or diuretic renography was performed every 3-6 months.

RESULTS

In 4/44 patients vesicoureteral reflux was detected as cause a of hydronephrosis. In the remaining 40 patients, diuretic renography showed a washout pattern not suggestive of obstruction in 32 (only one patient needed surgery due to pyohydronephrosis). An indeterminate washout pattern was detected in one patient (who required surgery due to worsening of the washout pattern). A pattern suggestive of obstruction was detected in seven patients, four of whom required surgery (three due to a decrease in differential renal function and one due to worsening of the degree of pelvic dilatation).

CONCLUSIONS

Diuretic renography is highly useful in risk stratification and in the management of newborn infants with hydronephrosis since infants with washout patterns not suggestive of obstruction will rarely develop obstructive hydronephrosis and can initially be followed-up with ultrasonography alone. In indeterminate and obstructive patterns, however, close monitoring that includes diuretic renography is mandatory.

Pattern of renal function deterioration as a predictive factor of unilateral ureteropelvic junction obstruction treatment

OBJECTIVES

To assess the process of renal function deterioration in patients with unilateral ureteropelvic junction (UPJ) obstruction and its impact on their treatment course.

MATERIAL AND METHODS

The files of patients treated for unilateral UPJ obstruction at our department from 1996 to 2003 were retrospectively reviewed. All patients were initially treated conservatively and followed up regularly. Criteria for conversion to surgical treatment were increase in anteroposterial renal pelvis diameter, increase in T(1/2) washout pattern, and drop of relative renal function (RRF) below 40% in diuretic renogram. Patients operated on because of multiple urinary infections, pelvic stones, or solitary kidneys were excluded. Patients were divided into group A, which included those whose treatment was converted from conservative to surgical, and group B in which patients were treated conservatively. All patients operated on underwent dismembered pyeloplasty.

RESULTS

Sixty-four patients with grade three or four hydronephrosis in postnatal ultrasound examination and an obstructive pattern in diuretic renogram were studied. All group A patients (n=47) reached an RRF below 40%; in 41 (87.2%) deterioration of RRF was detected in at least two sequential follow-up studies. In group B patients (n=17), deterioration was also detected in seven (41.1%) patients in two sequential studies (p<0.0005), although the RRF never dropped below 40%. No differences in gender, side of obstruction, or frequency of follow-up were detected between the two groups.

CONCLUSIONS

RRF deterioration and its progression for at least two sequential follow-ups could serve as a predictive factor for surgical treatment.

Ureteropelvic junction obstruction in children: 10 years' experience in one institution

We reviewed our experience over 10 years with pyeloplasty for ureteropelvic junction obstruction. Preoperative and postoperative isotope renal scans were performed to assess the surgical outcome, with particular emphasis on the postoperative change in renal function (RF). We retrospectively reviewed the medical records of 137 consecutive children with ureteropelvic obstruction operated between January 1994 and December 2003. A total of 109 kidneys in 102 patients were evaluated with renal echo and (99m)Tc-diethylenetriaminepentaacetic renography both before and after Anderson-Hynes dismembered pyeloplasty. The improvement of RF >5% was noted in 67 kidneys (61.5%), the function remained stable in 30 kidneys (27.5%), and it deteriorated (>5%) in 12 kidneys (11.0%). Five patients (4.6%) required repeat pyeloplasty for either prolonged urine leakage or reobstruction with deterioration in RF. Dismembered pyeloplasty in children with ureteropelvic junction obstruction is safe. The renal functional improvement can be expected in the majority of kidneys that have impaired function at presentation.

Postnatal unilateral pelviureteral junction obstruction: impact of pyeloplasty and conservative management on renal function

OBJECTIVES

To study the effect of pyeloplasty and conservative management on renal function in children with pelviureteral junction obstruction.

METHODS

This prospective study included 65 children postnatally diagnosed with unilateral pelviureteral junction obstruction. On the basis of the patients' symptoms and technetium-99m diethylenetriamine pentaacetic acid renal isotope scan findings, symptomatic patients or those with split function of the corresponding kidney of 40% or less were assigned to group 1 (n = 35) and underwent pyeloplasty. Asymptomatic patients with split function greater than 40% (group 2, n = 30) were treated conservatively. Patients who showed deterioration of renal function underwent pyeloplasty. The effect of both lines of treatment on renal function was evaluated.

RESULTS

After pyeloplasty, group 1 had improvement in the glomerular filtration rate (GFR) in 30 (85.7%), stabilization in 2 (5.7%), and deterioration in 3 (8.6%) patients. In group 1, the comparison between the mean value of the baseline GFR (17.1 +/- 7.7 mL/min) and its mean value at follow-up (28 +/- 6.3 mL/min) showed an increase of statistical significance (P <0.01). In the group 2 patients, conservative treatment resulted in improvement in the GFR in 12 (40%), stabilization in 3 (10%), and deterioration in 15 (50%) patients. In group 2, no significant difference was found between the mean baseline GFR (29.8 +/- 9.8 mL/min) and its mean value at follow-up (31.2 +/- 5.6 mL/min).

CONCLUSIONS

In patients with postnatal pelviureteral junction obstruction, early pyeloplasty is recommended if the corresponding GFR is 40% or less. Conservative management in patients with better function resulted in deterioration of renal function in 50%. Should this policy of treatment be chosen, meticulous follow-up is mandatory.

Dynamic gadolinium-enhanced magnetic resonance urography for assessing drainage in dilated pelvicalyceal systems with moderate renal function: preliminary results and comparison with diuresis renography

OBJECTIVE

To evaluate the use of dynamic gadolinium diethylenetriaminepenta-acetic acid (DTPA)-enhanced magnetic resonance urography (Gd-MRU) for assessing kidneys with markedly dilated pelvicalyceal systems and impaired function.

PATIENTS AND METHODS

Eight children (mean age 30 months, sd 25) were assessed, diagnosed as having gross unilateral hydronephrosis with a mean (sd) anteroposterior renal pelvic diameter of 36 (7) mm and reduced (30-40%) renal function. Dynamic Gd-MRU was performed after the patients were pre-loaded with intravenous fluid and diuretics, and comprised a dynamic T1-weighted sequence after Gd-DTPA (0.1 mmol/kg body weight) was administered, with a time-intensity curve of each kidney produced. Drainage was diagnosed by a clearly declining time-intensity curve and direct visualization of contrast medium within the ureter in several frames. High-grade or complete obstruction was diagnosed when drainage of contrast medium could not be detected. Gd-MRU results were compared with diuresis radionuclide (mercapto-acetyltriglycine, MAG3) renography within the same week. Unobstructive units detected by Gd-MRU were treated conservatively with a close follow-up by ultrasonography and radionuclide studies.

RESULTS

Diuresis MAG3 renography showed drainage in three dilated units and poor washout in five; in contrast, Gd-MRU showed drainage in seven dilated systems (three showed poor washout by MAG3), and obstruction in the remaining case. The unobstructed units detected by MRU under conservative treatment thus showed no further deterioration of renal function or progressive hydronephrosis in the subsequent follow-up (mean 18 months, range 15-23).

CONCLUSION

These preliminary results suggest that dynamic Gd-MRU is a useful noninvasive imaging method in distinguishing obstructive from unobstructive dilated systems, particularly in patients with hydronephrosis and reduced renal function.

Factors associated with the outcomes of children with unilateral ureteropelvic junction obstruction

PURPOSE

Children with congenital unilateral ureteropelvic junction obstruction were evaluated with 99mtechnetium-labeled diethylenetriaminepentaacetic acid furosemide renal scans (DTPA) to determine the correlation of tubular function tests, growth factors and renal function.

MATERIALS AND METHODS

A total of 38 children diagnosed with congenital unilateral ureteropelvic junction obstruction and recipients of dismembered pyeloplasty were prospectively studied. Before pyeloplasty split renal tubular function, creatinine clearance, urinary growth factors and a marker for apoptosis of each kidney were examined. Renal function of the obstructed kidney was evaluated by DTPA before and after pyeloplasty. Initially patients with DTPA greater than 40% were designated group 1 and those with DTPA 40% or less were assigned to group 2. After surgery followup patients with DTPA greater than 40% were designated the well preserved group and those with DTPA 40% or less were assigned to the poorly preserved group. Statistical analyses were performed to determine the best predictive variable for treatment.

RESULTS

Mean initial DTPA split renal function values of groups 1 and 2 were 47.3% and 28.8%, respectively and subsequently, they were 48.4% and 35.3%. Initial DTPA on the obstructed side of less than 35% had a 100% sensitivity and 100% positive predictive rate for a poorly preserved renal outcome. Among the various tubular functions, only percent fractional excretion of sodium and percent fractional excretion of chloride correlated with post-pyeloplasty DTPA. Urinary epidermal growth factor/creatinine correlated with preservation of renal function on postoperative DTPA renal scans. Although urinary transforming growth factor/creatinine levels and apoptosis ratios were higher on the obstructed side, they were not significantly different between the groups.

CONCLUSIONS

Proximal tubular dysfunction, such as increased percent fractional excretion of sodium and chloride, and initial DTPA 35% or less, suggest a high possibility of poorly preserved renal outcome. Urinary transforming growth factor-beta1 and apoptosis are not correlated with renal outcome. A high urinary level of epidermal growth factor might be a potential indicator of preservation of renal growth.

Ureteropelvic Junction Obstruction: Some new Acquisitions about Etiology, Pathophysiology and Diagnostics

The etiopathogenesis of uretero-pelvic junction obstruction (UPJO) has been the subject of many speculations and it remains, in some ways, a debatable matter. Some recently reported thorough research refer to neuro-mediated pathogenetic mechanisms rather than (or together with) myogenic ones.

Advances in US, radioisotopic functional imaging, CT and RM contribute to differentiate the obstructive conditions from the non-obstructive ones and to afford today a better assessment of renal functional damage. Particularly, diuretic renography is a non-invasive test for characterization of the renal functional abnormalities resulting from UPJO. Helical CT with angiography is a useful technique for identification of crossing vessels (pyelo-vascular tangle) which can be used for the pre-surgical planning of endopyelotomy. Endoluminal ultrasonography can be used to guide the position of the incision for endopyelotomy (US-guided endopyelotomy).

Laboratory examinations are important to determine the overall renal function (serum creatinine, acid-base balance, serum electrolytes, etc.), urinary MCP-1 and NAG (markers of tubular damage), and to rule out urinary tract infections.

The management of UPJO (watchful waiting; either open or laparoscopic dismembered pyeloplasty; endoluminal procedures) is greatly influenced by the diagnostic evaluation.

The paper aims to outline the advances in both physiopathology and diagnostics of UPJO on the basis of a review of the literature.

[Uropediatrics. Update and controversies]

On the occasion of the 25 Anniversary of the official Journal of the Spanish Urological Association, we do an overall view of Spanish Pediatric Urology (U.P.) at present time, and we perform an updating of the most prevalent and controversial aspects in U.P., as the foetal Urology, the vesicoureteral reflux and the pyelo-ureteral stenosis.

Does delaying pyeloplasty affect renal function in children with a prenatal diagnosis of pelvi-ureteric junction obstruction?

OBJECTIVE

To evaluate retrospectively children with an antenatal diagnosis of pelvi-ureteric junction (PUJ) obstruction who required pyeloplasty for deteriorating renal function during the follow-up, specifically assessing the recovery of function after surgery.

PATIENTS AND METHODS

Between 1988 and 2000, 44 consecutive patients with a prenatal diagnosis of PUJ obstruction who were initially treated by observation underwent pyeloplasty because their renal function deteriorated during the follow-up. Patients with bilateral disease, a single kidney or vesico-ureteric reflux were excluded from the study. The mean (sd) age of the patients was 13.3 (4.5) months and their mean (range) initial renal function 39.7 (30.4-45)%. In all patients the diagnostic criteria and indications for surgery were identical. The main indication for surgery was deteriorating renal function of >5%, confirmed by renal scintigraphy. Of 44 patients, 35 (77%) had severe dilatation of the renal pelvis by >3 cm. The mean (sd) deterioration in renal function during the follow-up, just before surgery, was 8.2 (2.4)%, and the mean time between the last acceptable renogram and the study showing deterioration was 8.3 (1.3) months; the mean follow-up was 5.1 (1.6) years. The results were assessed statistically using the unpaired nonparametric Mann-Whitney U-test.

RESULTS

An improvement in hydronephrosis was confirmed in all patients, with renal function returning to the initial levels in 36 of 44 (81%) patients 6-12 months after surgery, although in two patients renal function did not improve after surgery. There was no significant difference between the preoperative characteristics and the degree of hydronephrosis, renal function or patient age with the level of renal functional improvement after surgery.

CONCLUSION

In patients with an antenatal diagnosis of PUJ obstruction, expectant management is recommended and spares the children unnecessary surgery. Even if renal function deteriorates, delayed pyeloplasty recovers the initial functional level.

[Role of scintigraphic tests in upper urinary tract dilatation in children]

The diuresis renography has an important place in the management of upper urinary tract dilatation in children. This non-aggressive and low irradiant exploration is very helpful to determine if hydronephrosis is obstructive or not and to evaluate the renal function impairment. The protocol of exam must be particularly rigorous and interpretation should take into account physiopathological factors that influence provocated diuresis. A well patient hydration and if necessary a bladder catheter are required. The MAG-3 is the radiopharmaceutical of choice especially in newborn and infants. The furosemide administration at 20 minutes after radiotracer injection is the most commonly used protocol and is generally sufficient to classify the urinary dilatation. Equivocal cases and symptomatic forms can benefit from a modified protocol in which furosemide is administered 15 minutes before radiotracer injection (F-15). False positive tests may result from a marked dilatation or renal function reduction. The place of diuresis renography in management of neonatal hydronephrosis is controversial, particularly because of the dynamic and evolving nature of this pathology.

[Diuretic renography in the diagnostic approach of prenatal hydronephrosis]

OBJECTIVE

To verify the utility of diuretic renography using 99mTc-MAG3 in the evaluation of the urinary tract obstruction in patients with prenatal diagnosis of hydronephrosis. In a neonate with upper urinary tract dilatation, it is difficult to differentiate a true obstruction from a dilated non-obstructed system.

MATERIAL AND METHODS

The retrospective study (january 1993-december 1998) included 40 consecutive patients selected from 181 newborns with a prenatal diagnosis of hydronephrosis. The mean age of the performance of the first renography was 2.6 months.

RESULTS

The final diagnosis (once the vesicoureteral reflux was ruled out) was: ureteropelvic junction obstruction (UPJ) 16, megaureter 15, ureterocele 3 and stasis 6. Conservative treatment was applied in most of the patients. Nevertheless, 17 of them needed surgical treatment due to the high risk of the permanent renal damage.

CONCLUSIONS

1) UPJ is the most frequent cause of neonatal hydronephrosis (NH) and consequently, of the request for diuretic renographies. The renography with 99mTc-MAG3 has the greatest influence in the therapeutic decision (identifying who should be operated on and when this should be done), due to the fact that it is the disease with the highest rate of surgical interventions. 2). The surgical indication in NH is based on the diuretic renography parameters and/or on the presence of symptomatology. In our series of surgical patients, none of those who had a differential renal function <20% with regard to the contralateral one showed recuperation after surgery (control 6 months later).

Renal function before and after pyeloplasty: does it improve?

PURPOSE

Controversy exists concerning the timing of surgical correction of presumed ureteropelvic junction obstruction. Different opinions on the timing of intervention focus on renal function deterioration with time, poor initial relative function, or obstructive drainage curves and/or drainage time on diuretic renography. We retrospectively determined whether there is any improvement in renal function after pyeloplasty for presumed renal obstruction.

MATERIALS AND METHODS

We retrospectively reviewed the charts of patients who underwent pyeloplasty between 1990 and 1997 in whom preoperative and postoperative diuretic renography data were available. Patients were excluded from review when they had bilateral ureteropelvic junction obstruction, a solitary kidney, associated vesicoureteral reflux, or other bladder or ureteral abnormalities, and when preoperative and postoperative renography studies were not available.

RESULTS

Complete data were available for review in 79 patients 2 weeks to 18 years old (median age 6 months). Of the patients 73% were male and 73% of the affected kidneys were on the left side. Prenatal hydronephrosis had been diagnosed in 58 patients (73%), of whom 19 (33%) were observed for a variable period before pyeloplasty was performed. In all cases diuretic renography performed at the same institution using a standard protocol revealed a drainage time of 20 minutes or greater preoperatively, while in 58 cases a measurable drainage time was never achieved. As a rule, drainage improved postoperatively (mean and median 25 and 16 minutes, respectively). Open renal biopsy done at pyeloplasty in 54 patients was normal in 29. Preoperatively renal function ranged from 5 to 67% (mean and median 41 and 45, respectively). In all patients the paired t test showed no statistical difference in preoperative and postoperative renal function (p = 0.078, 95% confidence interval -3.451 to 0.185). There was no statistical change in renal function in patients with an abnormal renal biopsy regardless of the severity of renal scarring (p = 0.38) or when renal function was 40% or less (mean preoperative versus postoperative 29.7 versus 28.4%, p = 0.46). The group with greater than 40% function preoperatively had no relevant difference in function before or after surgery (mean 49.7 versus 47.8%, p = 0.065). Prenatally screened patients who were initially observed had a statistically significant difference in renal function before and after pyeloplasty (mean 45.6 versus 43%, p = 0.002).

CONCLUSIONS

Renal function did not improve after pyeloplasty regardless of the initial level of relative function. Renal scan revealed that differential function decreased after pyeloplasty in some patients in whom hydronephrosis was detected prenatally and who were initially followed with observation. In our opinion waiting for renal function to decrease before considering pyeloplasty is not warranted, since function does not improve even when obstruction is corrected and drainage time improves.

Renal function before and after pyeloplasty: does it improve?

PURPOSE

Controversy exists concerning the timing of surgical correction of presumed ureteropelvic junction obstruction. Different opinions on the timing of intervention focus on renal function deterioration with time, poor initial relative function, or obstructive drainage curves and/or drainage time on diuretic renography. We retrospectively determined whether there is any improvement in renal function after pyeloplasty for presumed renal obstruction.

MATERIALS AND METHODS

We retrospectively reviewed the charts of patients who underwent pyeloplasty between 1990 and 1997 in whom preoperative and postoperative diuretic renography data were available. Patients were excluded from review when they had bilateral ureteropelvic junction obstruction, a solitary kidney, associated vesicoureteral reflux, or other bladder or ureteral abnormalities, and when preoperative and postoperative renography studies were not available.

RESULTS

Complete data were available for review in 79 patients 2 weeks to 18 years old (median age 6 months). Of the patients 73% were male and 73% of the affected kidneys were on the left side. Prenatal hydronephrosis had been diagnosed in 58 patients (73%), of whom 19 (33%) were observed for a variable period before pyeloplasty was performed. In all cases diuretic renography performed at the same institution using a standard protocol revealed a drainage time of 20 minutes or greater preoperatively, while in 58 cases a measurable drainage time was never achieved. As a rule, drainage improved postoperatively (mean and median 25 and 16 minutes, respectively). Open renal biopsy done at pyeloplasty in 54 patients was normal in 29. Preoperatively renal function ranged from 5 to 67% (mean and median 41 and 45, respectively). In all patients the paired t test showed no statistical difference in preoperative and postoperative renal function (p = 0.078, 95% confidence interval -3.451 to 0.185). There was no statistical change in renal function in patients with an abnormal renal biopsy regardless of the severity of renal scarring (p = 0.38) or when renal function was 40% or less (mean preoperative versus postoperative 29.7 versus 28.4%, p = 0.46). The group with greater than 40% function preoperatively had no relevant difference in function before or after surgery (mean 49.7 versus 47.8%, p = 0.065). Prenatally screened patients who were initially observed had a statistically significant difference in renal function before and after pyeloplasty (mean 45.6 versus 43%, p = 0.002).

CONCLUSIONS

Renal function did not improve after pyeloplasty regardless of the initial level of relative function. Renal scan revealed that differential function decreased after pyeloplasty in some patients in whom hydronephrosis was detected prenatally and who were initially followed with observation. In our opinion waiting for renal function to decrease before considering pyeloplasty is not warranted, since function does not improve even when obstruction is corrected and drainage time improves.

Does early detection of ureteropelvic junction obstruction improve surgical outcome in terms of renal function?

PURPOSE

Prenatal ultrasound leads to the early detection of hydronephrosis. When followed by the early diagnosis of ureteropelvic junction obstruction surgical treatment, if indicated, is associated with minimal morbidity. We attempt to prove the benefits of this therapeutical approach from the point of view of renal function.

MATERIALS AND METHODS

From 1979 to 1997, 452 patients with ureteropelvic junction obstruction underwent dismembered pyeloplasty. Of these patients 113 with comparable data were retrospectively evaluated. Patients were divided into group 1-50 who presented with prenatal hydronephrosis and group 2-63 with neonatal hydronephrosis who were lost to followup and who then presented with symptoms leading to the diagnosis of ureteropelvic junction obstruction. In each group the diagnostic criteria and indications for surgery were identical based on symptomatology, ultrasound and renal scan. Patients with bilateral disease, solitary kidney or vesicoureteral reflux were excluded from study. In groups 1 and 2 median patient age at surgery was 11 months and 5 years, and average postoperative followup was 4.2 and 3.2 years, respectively.

RESULTS

In 41 of the 50 group 1 and 60 of the 63 group 2 patients hydronephrosis was severe and the renal pelvis was more than 3 cm. wide. Poor relative renal function (less than 30%) was significantly more pronounced in group 2 than in group 1 (56 of 63 patients or 89% versus 6 of 50 or 12%, p <0.05). In all 113 patients postoperative followup ultrasound and renal scan revealed significant improvement in hydronephrosis and washout curve pattern. There was a significant difference in the 2 groups in regard to renal function improvement postoperatively (66% of group 1 versus 16% of group 2 patients, p <0.05).

CONCLUSIONS

We believe that patients who undergo prenatal imaging and are diagnosed early with ureteropelvic junction obstruction should be carefully and meticulously followed. Special efforts should be made to ensure that patients are not lost to followup. After any sign of deterioration develops early surgery is indicated. According to our data operative treatment results in improved renal function.

Does early detection of ureteropelvic junction obstruction improve surgical outcome in terms of renal function?

PURPOSE

Prenatal ultrasound leads to the early detection of hydronephrosis. When followed by the early diagnosis of ureteropelvic junction obstruction surgical treatment, if indicated, is associated with minimal morbidity. We attempt to prove the benefits of this therapeutical approach from the point of view of renal function.

MATERIALS AND METHODS

From 1979 to 1997, 452 patients with ureteropelvic junction obstruction underwent dismembered pyeloplasty. Of these patients 113 with comparable data were retrospectively evaluated. Patients were divided into group 1-50 who presented with prenatal hydronephrosis and group 2-63 with neonatal hydronephrosis who were lost to followup and who then presented with symptoms leading to the diagnosis of ureteropelvic junction obstruction. In each group the diagnostic criteria and indications for surgery were identical based on symptomatology, ultrasound and renal scan. Patients with bilateral disease, solitary kidney or vesicoureteral reflux were excluded from study. In groups 1 and 2 median patient age at surgery was 11 months and 5 years, and average postoperative followup was 4.2 and 3.2 years, respectively.

RESULTS

In 41 of the 50 group 1 and 60 of the 63 group 2 patients hydronephrosis was severe and the renal pelvis was more than 3 cm. wide. Poor relative renal function (less than 30%) was significantly more pronounced in group 2 than in group 1 (56 of 63 patients or 89% versus 6 of 50 or 12%, p <0.05). In all 113 patients postoperative followup ultrasound and renal scan revealed significant improvement in hydronephrosis and washout curve pattern. There was a significant difference in the 2 groups in regard to renal function improvement postoperatively (66% of group 1 versus 16% of group 2 patients, p <0.05).

CONCLUSIONS

We believe that patients who undergo prenatal imaging and are diagnosed early with ureteropelvic junction obstruction should be carefully and meticulously followed. Special efforts should be made to ensure that patients are not lost to followup. After any sign of deterioration develops early surgery is indicated. According to our data operative treatment results in improved renal function.