Management and outcome of antenatally diagnosed hydronephrosis

Primary non-surgical management of unilateral ureteropelvic junction obstruction in children: a systematic review

Ureteropelvic junction obstruction (UPJO) is the most common obstructive uropathy and its optimal management remains controversial. However, there is a current trend towards non-surgical management. We aimed to determine the effects of the non-surgical management in children with unilateral UPJO. For a systematic review, we searched MEDLINE, EMBASE, CENTRAL, clinical trials registries, and selected conference proceedings for eligible studies. Any type of study reporting the outcomes renal function, secondary surgical intervention, drainage pattern or hydronephrosis of non-surgical management in children with unilateral UPJO was included. Data from 20 studies were extracted and evaluated by two independent authors. The pooled prevalence was 21% for split renal function deterioration, 27.9% for secondary surgical intervention, 3.2% for progressive hydronephrosis, and 82.2% for improved drainage pattern. Not all patients with surgical intervention regained split renal function from enrolment. Renal imaging methods did not strongly correlate with each other. Many studies had to be excluded because of a lack of detection of an obstruction or mixed populations with bilateral UPJO or other uropathies. The variable definitions of UPJO, different criteria for surgical intervention, incongruity of management protocols, and the imprecise reporting of outcomes were limiting factors in the comparability of the results, leading to heterogeneity in meta-analyses. Although the available evidence cannot recommend or refute the current non-surgical management, the systematic review clarifies aspects of the ongoing controversy by providing realistic estimates for non-surgical management in children with unilateral UPJO. Additionally, it reveals unclear potential risks, particularly for long-term outcomes, which were rarely reported.

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.

Requirements for accurately diagnosing chronic partial upper urinary tract obstruction in children with hydronephrosis

Successful management of hydronephrosis in the newborn requires early accurate diagnosis to identify or exclude ureteropelvic junction obstruction. However, the presence of hydronephrosis does not define obstruction and displays unique behavior in the newborn. The hydronephrotic kidney usually has nearly normal differential renal function at birth, has not been subjected to progressive dilation and except for pelvocaliectasis does not often show signs of high-grade obstruction. Furthermore, severe hydronephrosis resolves spontaneously in more than 65% of newborns with differential renal function stable or improving. The diagnosis of obstruction in newborn hydronephrosis is challenging because the currently available diagnostic tests, ultrasonography and diuretic renography have demonstrated inaccuracy in diagnosing obstruction and predicting which hydronephrotic kidney will undergo deterioration if untreated. Accurate diagnosis of obstruction is possible but it requires an understanding of the uniqueness of both the pathophysiology of obstruction and the biology of the kidney and renal collecting system in this age group. We examine here the requirements for making an accurate diagnosis of obstruction in the young child with hydronephrosis.

Long-term followup of prenatally detected severe bilateral newborn hydronephrosis initially managed nonoperatively

PURPOSE

We determine the outcome of severe bilateral primary ureteropelvic junction type hydronephrosis detected prenatally and managed postnatally with an initially nonoperative protocol.

MATERIALS AND METHODS

A total of 19 newborns (38 kidneys) with prenatally diagnosed primary grade 3 to 4 bilateral hydronephrosis were followed nonoperatively for a mean of 54 months (range 14 to 187). If urinary obstruction with evidence of renal deterioration (decreased differential function and/or progressive hydronephrosis) occurred pyeloplasty was performed.

RESULTS

Pyeloplasty was required in 13 kidneys (35%) in 9 patients (bilateral 4, unilateral 5). Age at pyeloplasty ranged from 2 to 22 months (mean 6.5) in 12 patients and 64 months in 1. The remaining 25 kidneys were followed nonoperatively (bilateral 20, unilateral 5). At last followup the Society for Fetal Urology grade of hydronephrosis in kidneys followed nonoperatively was 0 to 2 in 21 and 3 in 4, compared to 0 to 2 in 9 and Society for Fetal Urology 3 in 4 kidneys treated with pyeloplasty. Mean followup required for the most severely hydronephrotic kidney to achieve maximum ultrasound improvement was 10 months (range 3 to 34) for kidneys followed nonoperatively and 14 months (4-31) for kidneys after pyeloplasty. Differential renal function was measured in each kidney pair and compared using the difference in percent function between the 2 kidneys. In the nonoperative group mean initial difference in percent function was 8% (range 6% to 20%) and mean final difference was 5% (2% to 8%). In the pyeloplasty group mean initial difference in percent function was 16% (range 8% to 30%) and mean final difference was 7% (2% to 16%). With close followup and prompt pyeloplasty renal function improved to greater than pre-deterioration levels in all kidneys.

CONCLUSIONS

These data represent the natural history of severe bilateral newborn hydronephrosis. Renal dilatation and function improve with time in most kidneys. Close followup is required in the first 2 years of life to identify the subgroup (35%) of children with obstruction that requires prompt surgery. Such an approach prevented permanent loss of renal function. Nonoperative management with close followup during the first 2 years appears to be a safe and recommended approach for neonates with primary bilateral ureteropelvic junction type hydronephrosis.

The long-term followup of newborns with severe unilateral hydronephrosis initially treated nonoperatively

PURPOSE

During the last decade it has become apparent that prenatally detected, unilateral severe hydronephrosis does not necessarily represent obstruction and may spontaneously improve or resolve postnatally. To define its natural history better we performed a long-term (mean 78 months) followup study of infants with hydronephrosis.

MATERIALS AND METHODS

A total of 104 newborns with antenatally diagnosed, primary, unilateral severe hydronephrosis were followed nonoperatively unless evidence of renal deterioration occurred for which pyeloplasty was performed.

RESULTS

All 23 infants (22%) who required pyeloplasty were younger than 18 months and had progressive hydronephrosis and/or reduction in differential renal function. Differential function exceeded predeterioration levels in all kidneys postoperatively. Of those cases followed nonoperatively hydronephrosis resolved in 69% and improved in 31%. Mean time to maximum improvement of hydronephrosis was 2.5 years. In 76% of those cases followed nonoperatively initial differential function was greater than 40% and final function averaged 49%. In the remaining 24% of cases differential function was less than 40% (mean 23%), and in an average of 18 months differential function increased to a mean of 47%. Initial half-time in nonoperative cases was greater than 30 minutes in 37%, 20 to 30 in 21% and less than 20 in 42%. Final half-time was greater than 30 minutes in 16%, 20 to 30 in 17% and less than 20 in 67%. Half-time was greater than 30 minutes in 87% of the patients and 20 to 30 in 4% before, and greater than 30 in 10%, 20 to 30 in 27% and less than 20 in 63% after pyeloplasty.

CONCLUSIONS

Unilateral newborn hydronephrosis appears to be relatively benign and in most instances dilatation and renal function improve with time. However, close followup is necessary to identify the subgroup of less than 25% of infants with obstruction because prompt pyeloplasty will prevent permanent loss of renal function. Standard tests for assessing obstruction in older patients appear to be invalid in infants because prolonged half-time and/or high grade hydronephrosis is neither an indicator of obstruction or surgery. Nonoperative treatment with close followup especially during the first 2 years is safe and recommended for these children.

Neonatal management of unilateral hydronephrosis. Role for delayed intervention

Hydronephrosis should be managed no differently in the newborn than in any other age group: UPJ obstruction should be surgically corrected as soon as the diagnosis is made. Unfortunately, the diagnosis of obstruction in the newborn with hydronephrosis is difficult and the traditional tests used in the older child or adult are not valid. Because newborn hydronephrosis is a relatively benign condition, surgical intervention should be delayed until the diagnosis of obstruction is proven. A protocol for evaluating the newborn with hydronephrosis is presented.