The case for relief of ureteropelvic junction obstruction in neonates and young children at time of diagnosis

Symptomatology and Clinic of Hydronephrosis Associated With Uretero Pelvic Junction Anomalies

The most common cause of hydronephrosis in the pediatric age group is ureteropelvic junction-type hydronephrosis (UPJHN). Since the advent of widespread maternal ultrasound screening, clinical presentation of hydronephrosis associated with UPJ anomalies has changed dramatically. Today most cases are diagnosed in the prenatal period, and neonates present without signs or symptoms. For those who are not detected at birth, UPJHN eventually presents throughout childhood and even adulthood with various symptoms. Clinical picture of UPJHN highly depends on the presence and severity of obstruction, and whether it affects single or both kidneys. Abdominal or flank pain, abdominal mass, hematuria, kidney stones, urinary tract infections (UTI), and gastrointestinal discomfort are the main symptoms of UPJHN in childhood. Other less common findings in such patients are growth retardation, anemia, and hypertension. UTI is a relatively rare condition in UPJHN cases, but it may occur as pyelonephritis. Vesicoureteric reflux should be kept in mind as a concomitant pathology in pediatric UPJHN that develop febrile UTI. Although many UPJHN cases are known to improve over time, close clinical observation is critical in order to avoid irreversible kidney damage. The most appropriate approach is to follow-up the patients considering the presence of symptoms, the severity of hydronephrosis and the decrease in kidney function and, if necessary, to decide on early surgical intervention.

Surgery versus non-surgical management for unilateral ureteric-pelvic junction obstruction in newborns and infants less than two years of age

BACKGROUND

Unilateral ureteric-pelvic junction obstruction (UPJO) is the most common cause of obstructive uropathy and may lead to renal impairment and loss of renal function. The current diagnostic approach with renal imaging cannot reliably determine which newborns and infants less than two years of age have a significant obstruction and are at risk for permanent kidney damage. There is therefore no consensus on optimal therapeutic management of unilateral UPJO.

OBJECTIVES

To assess the effects of surgical versus non-surgical treatment options for newborns and infants less than two years of age with unilateral UPJO.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 6, 2016), MEDLINE/Ovid, and EMBASE/Ovid databases from their inception to 13 June 2016. We searched the reference lists of potentially relevant studies without using any language restriction. We also searched the following trial registers for relevant registered studies: www.clinicaltrials.gov/; ISRCTN registry (controlled-trials.com/); www.trialscentral.org/; apps.who.int/trialsearch/; www.drks.de/; and www.anzctr.org.au/trialSearch.aspx.

SELECTION CRITERIA

We selected randomised and quasi-randomised controlled trials comparing surgical with non-surgical interventions for the treatment of unilateral UPJO.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and risk of bias of included studies and extracted data. In case of disagreements we consulted a third review author. The data reported in the two included studies did not allow us to perform a meta-analysis.

MAIN RESULTS

We found only two studies at high risk of bias that were eligible for inclusion in this review. The total sample size, including both trials, was small (n = 107 participants less than six months of age from the UK and USA), and not all prespecified outcome measures were assessed. Reported measures only accounted for the short-term follow-ups. The mean split renal function was not statistically different between the surgical and non-surgical group at the six-month or one-year time point (very low-quality evidence). The surgical group showed a significantly less obstructed drainage pattern and a lower urinary tract dilatation than the non-surgical group (very low-quality evidence). Transfer from the non-surgical group to the surgical group was reported for about one out of five participants. Split renal function after secondary surgical intervention was reported with variable results, but most of the participants reverted to pre-deteriorated values. The studies either provided no or insufficient data on the following outcome measures: postoperative complications, UPJO-associated clinical symptoms, costs of interventions, radiation exposure, quality of life, and adverse effects.

AUTHORS' CONCLUSIONS

We found limited evidence assessing the benefits and harms of surgical compared to non-surgical treatment options for newborns and infants less than two years of age with unilateral UPJO. The majority of participants in the non-surgical treatment group did not experience any significant deterioration of split renal function, and only about 20% of them underwent secondary surgical intervention, with minor risk of permanent deteriorated split renal function. The study follow-up period was too short to assess the long-term effects on split renal function in both treatment groups. We need further randomised controlled trials with sufficient statistical power and an adequate follow-up period to determine the optimal therapy for newborns and infants less than two years of age with unilateral UPJO.

Delayed decrease in differential renal function after successful pyeloplasty in children with unilateral antenatally detected hydronephrosis

AIM

The aim of this study was to evaluate functional outcome of congenital hydronephrotic kidney.

METHODS

The records of consecutive children who underwent pyeloplasty for unilateral prenatally detected ureteropelvic junction obstruction were reviewed. Renal function was assessed renographically before and after surgery. Mean follow-up period was 100 months.

RESULTS

Sufficient pre- and postoperative data were available for 60 children. Differential renal function (DRF) improved in 14 (23%) and decreased in nine (15%) of 60 patients in the early postoperative period. DRF improved in seven (18%) and decreased in 13 (34%) of 38 patients at the end of follow-up. Five of 14 patients with increased DRF at early postoperative scan returned to the preoperative level at the end of follow-up. No patients with decreased DRF at early postoperative scan showed any recovery in DRF and progressive decrease was seen in four of nine children.

CONCLUSIONS

The DRF was not stable in some patients after successful pyeloplasty. In some patients impairment of renal function came to be apparent with time. Improvement of DRF may be a transient phenomenon seen in the early postoperative period. To avoid overestimation of functional recovery, long-term follow-up with delayed renographic evaluation is recommended.

[Specificities of the treatment of abnormal pyelo-ureteral junction in children]

Pyelo-ureteral junction abnormalities in children are most frequently discovered by prenatal ultrasound investigation. Most pyeloplasties by resection-anastomosis of the pyelo-ureteral junction are performed in young infants, usually with a posterior approach, patient prone. The indication and type of urinary pyelic drain remain debated: simple nephrostomy or double J drain. Ureteral-caliceal anastomosis is an interesting approach to rare surgical reoperations, particularly with major pyelo-ureteral dilatation. Laparoscopic surgery may prove usefulness in less small children. Endopyelotomy gives good results for post-operative stenoses.

Tratamiento endourológico de la estenosis pieloureteral congénita

OBJECTIVES

To report our experience with endourologic methods in the treatment of pyeloureteral stenosis in children.

MATERIALS AND METHODS

From July 2004, 7 patients from 9 months to 15 years old with pyeloureteral junction stenosis (PUJ) diagnosis underwent endourologic repair. An endourological dilatation was made under radioscopic control. The procedures consist of an initial cystoscopy with a retrograde placement of catheter (4 or 5 Fr) and the guide wire (0,014''-or 0,035''). The high pressure balloon (3 to 5 Fr) was then railroad over the wire and positioned across the stenosis for dilatation. A double J stent (3 to 6 Fr) was then introduced, remaining it during 6 weeks.

RESULTS

There was no intraoperative complications. Median inhospital stay was 2 days (range, 2 to 8). The double J stent was removed without complications. All patients are asymptomatic with improvement in excretion times (MAG3 renography) and antero-posterior renal pelvis diameter (ultrasound measurement).

CONCLUSIONS

Balloon dilatation is a viable option in the management of PUJ obstruction even in children under one year old, with minimal morbidity.

Early release of neonatal ureteral obstruction preserves renal function

The incidence of congenital hydronephrosis is approximately 1% and is often associated with renal insufficiency. It is unknown whether early release is essential to prevent deterioration of renal function. Rats were subjected to partial unilateral ureteral obstruction (PUUO) on postnatal day 2. The obstruction was left in place or released after 1 or 4 wk. Renal blood flow (RBF) and kidney size were measured sequentially over 24 wk using MRI. In rats in which the obstruction was left in place, RBF of the obstructed kidney was progressively reduced to 0.92 +/- 0.17 vs. 1.79 +/- 0.12 ml.min(-1).100 g body wt(-1) (P < 0.05) after 24 wk. Similarly, glomerular filtration rate of the obstructed kidney was severely reduced at 24 wk: 172 +/- 36 vs. 306 +/- 42 microl.min(-1).100 g body wt(-1) (P < 0.05). These changes were preceded by development of severe hydronephrosis and obstructive nephropathy with a reduction in total protein content: 45 +/- 3 vs. 58 +/- 4 mg/kidney. Moreover, nonreleased PUUO caused a marked natriuresis (0.32 +/- 0.07 vs. 0.11 +/- 0.02 micromol.min(-1).100 g body wt(-1), P < 0.05) and impaired solute free water reabsorption (0.47 +/- 0.16 vs. 2.71 +/- 0.67 microl.min(-1).100 g body wt(-1), P < 0.05), consistent with a significant downregulation of Na-K-ATPase to 62 +/- 7%, aquaporin-1 to 53 +/- 3%, and aquaporin-3 to 53 +/- 7% of sham levels. Release after 1 wk completely prevented development of hydronephrosis, reduction in RBF and glomerular filtration rate, and downregulation of renal transport proteins, whereas release after 4 wk had no effect. These results suggest that early release of neonatal obstruction provides dramatically better protection of renal function than release of obstruction after the maturation process is completed.

Management of neonatal ureteropelvic junction obstruction

No topic in urology is more contentious than the management of neonatal ureteropelvic junction obstruction. Those favoring early diagnosis and correction of obstruction in early infancy cite excellent return of function and superior surgical results compared with delayed repair. Others believe that hydronephrosis improves or resolves with growth in many instances. In the most widely quoted series, almost all such patients improved. This article attempts to separate opinion from fact. The arguments for early surgery and for observation, even when obstruction has been diagnosed, are reviewed. Several experiences with long-term surveillance are summarized.

[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).

Apparent unilateral ureteropelvic junction obstruction in the newborn: expectations for resolution

PURPOSE

We retrospectively reviewed the records of patients with prenatal hydronephrosis to characterize those in whom it was more likely to resolve with conservative management.

MATERIALS AND METHODS

We studied 51 patients in a 4-year period who presented with nonspecific unilateral hydronephrosis diagnosed by prenatal and confirmed by postnatal sonography. Patients were followed with sequential nuclear renograms with furosemide washout to evaluate function and drainage. In all cases a nonoperative approach was attempted. Pyeloplasty was performed only for poor or decreasing kidney function and/or drainage.

RESULTS

Four of the 51 patients were lost to followup, 21 of the remaining 47 (45%) eventually underwent surgery, and 26 (55%) had complete normalization of renal function and washout pattern without surgery. There was no statistically significant correlation between hydronephrosis grade on initial postnatal sonography and the likelihood of nonsurgical resolution. However, the shape of the washout curve on nuclear renography was informative for predicting outcome, since 86% of the cases with a nonobstructive drainage pattern normalized without surgery, while 62% with indeterminate and only 18% with obstructive curves resolved with conservative management (p <0.01). Notably in 83% of the cases of normalization without surgery resolution occurred before age 18 months. Also, an initial obstructed washout pattern was more likely to be associated with a poor outcome. Of the 6 patients with less than 40% final differential function 5 had an obstructed washout pattern on the initial nuclear renogram.

CONCLUSIONS

Patients diagnosed by prenatal ultrasound with apparent unilateral ureteropelvic junction obstruction generally do well with conservative treatment. However, those who present with an obstructed washout pattern are less likely to have resolution without surgery and more likely to have poor final differential function.

Surgery versus observation for managing obstructive grade 3 to 4 unilateral hydronephrosis: a report from the Society for Fetal Urology

PURPOSE

The Society for Fetal Urology has undertaken the first multicenter prospective randomized study of high grade obstructive unilateral hydronephrosis to evaluate the natural history of untreated obstruction and compare it to the benefits of pyeloplasty.

MATERIALS AND METHODS

Since 1991, infants with isolated unilateral Society for Fetal Urology grade 3 hydronephrosis and ipsilateral obstruction with greater than 40% differential renal function on well tempered renography were studied. Patients were randomly assigned to observation or pyeloplasty groups. Renal ultrasound and well tempered renography were performed biannually for 1 year and yearly thereafter. Crossover criteria for surgery included concurrent worsening of isotope washout and increasing grade of hydronephrosis or a greater than 10% point loss in percent differential renal function that was noted between studies. The end point of the study was the 3-year anniversary of randomization.

RESULTS

A total of 32 infants from 10 centers were randomized equally to 2 groups. The starting grade of hydronephrosis and percent differential renal function were similar between the 2 groups. At 6 months and 1 year the grade of hydronephrosis was significantly reduced (p < 0.02) and well tempered renography was significantly more likely to demonstrate no obstruction (p < 0.03) in the surgical group compared with the observation group. The mean percent differential renal function remained stable and similar in both groups. Reduced hydronephrosis and resolution of obstruction in the surgery group persisted as a trend at the 2 and 3-year anniversaries. In the observation group 4 patients (25%) showed enough renal deterioration to qualify for crossover to surgery.

CONCLUSIONS

Infant pyeloplasty significantly improved the grade of hydronephrosis and drainage pattern at 6 months and 1 year postoperatively, when compared with observation. Renal function stabilization was similar for either management approach. However, 25% of the patients satisfied objective criteria of status deterioration requiring pyeloplasty.

Antenatal hydronephrosis. Fetal and neonatal management

As many as 1% of newborn infants have a prenatal diagnosis of hydronephrosis or significant renal pelvic dilation. Hydronephrosis often is caused by nonobstructive conditions. The likelihood of significant urologic pathology is directly related to the size of the fetal renal pelvis, and 90% with an anteroposterior diameter more than 2 cm need surgery or long-term urologic medical care. Following delivery, antibiotic prophylaxis should be administered and a renal sonogram and voiding cystourethrogram should be obtained. If there is grade 3 or 4 hydronephrosis, usually a diuretic renogram is recommended also. Pediatric urologic or pediatric nephrologic consultation usually is helpful in planing evaluation and treatment. Prenatal recognition of hydronephrosis allows neonatal diagnosis and treatment of urologic pathology, preventing complications of pyelonephritis and obstruction.

Neonatal hydronephrosis--the controversy and the management

Neonatal hydronephrosis is being detected with increasing frequency. The majority of these cases have a tendency to resolve during infancy. Hydronephrosis is an anatomical entity that is not synonymous with obstruction. Review of the pathoembryology, the pathophysiology, the diagnostic techniques currently used and the natural history of hydronephrosis is given. The management and the controversies involved are discussed.

Renal histological changes secondary to ureteropelvic junction obstruction

The treatment of children with apparent ureteropelvic junction obstruction is controversial. In an asymptomatic infant or child the decision to recommend pyeloplasty usually is based on interpretation of the renal scan. We retrospectively analyzed the renal biopsy obtained during pyeloplasty in 55 children. Histological changes were compared to the differential renal function revealed on the preoperative renal scan. Histological changes were graded on a scale of I to V; I--normal, II--mild dilatation of the collecting tubules or Bowman's space and III to V--progressively severe changes of obstructive uropathy, including reduced glomerular number, glomerular hyalinization, cortical cysts and interstitial inflammation. Patient age ranged from 4 days to 19 years (mean 4.8 years). Mean differential function according to histological grade was I--49%, II--43%, III--42%, IV--30% and V--25%. Of 33 patients with a differential function of 40% or greater 26 (79%) had a grade I or II biopsy, while 21% had a more significant alteration in renal histology. In contrast when the differential function was less than 40% 6 of 18 patients (33%) had grade I or II disease on biopsy. In conclusion, in approximately 25% of children with ureteropelvic junction obstruction there is a disparity between preoperative differential renal function computed during diuretic renography and renal biopsy.

Are modern imaging techniques over diagnosing ureteropelvic junction obstruction?

Since the widespread use of real-time ultrasonography in the early 1980s, ureteropelvic junction obstruction has been diagnosed at earlier ages and prenatally on a presumptive basis. However, substantial controversy exists over the diagnosis and treatment of ureteropelvic junction obstruction. We conducted an epidemiological study to determine if modern imaging techniques are leading to the over diagnosis of ureteropelvic junction obstruction. Records were collected retrospectively from 3 hospitals serving 2 adjacent counties to determine the number of pyeloplasties performed in 1970 to 1992. The 2 university hospitals and 1 large private hospital provide a wide variety of services and choice of urologists, and so it was assumed that most patients requiring pyeloplasty in the area would be captured. Of the 555 pyeloplasties 240 (43%) were performed on children 12 years old or younger. Logistic regression analysis revealed an overall increase of pyeloplasties per year of 56.8% in 23 years, which was not markedly different from the population growth in the area in the same period (49.3%). A statistically significant increase in the number of pyeloplasties performed in the first year of life was noted. This trend appeared to begin in 1981: 8 pyeloplasties were performed in the first year of life between 1970 and 1980 compared to 91 between 1981 and 1992. Pyeloplasties in children 1 to 6 years old increased with time at a much lower rate that was not statistically significant and the number of pyeloplasties decreased in those 7 to 12 years old. Therefore, it appears that modern imaging techniques are not leading to an over diagnosis of ureteropelvic junction obstruction but to detection of the disease at an earlier age.

Nonoperative management of unilateral neonatal hydronephrosis

We followed nonoperatively 45 neonates with unilateral hydronephrosis and suspected ureteropelvic junction obstruction for 30 months, regardless of the degree of hydronephrosis, shape of diuretic renogram washout curve or initial degree of functional impairment. Of the patients 30 had mild hydronephrosis and no renal deterioration, while 15 had severe hydronephrosis, an obstructed diuretic renogram and markedly decreased hydronephrotic kidney function. During followup percentage and absolute renal function rapidly increased in all patients, hydronephrosis improved in 7 and contralateral compensatory hypertrophy did not develop in any. These findings help to define the natural history of untreated hydronephrosis, suggest that many newborn kidneys with severe hydronephrosis are not obstructed despite even profound initial decreases in renal function and demonstrate that traditional tests for diagnosing obstruction are inaccurate in this age group. Therefore, the methods for assessing obstruction and the indications for surgical intervention in these patients require reexamination.