Postnatal follow-up of antenatal hydronephrosis: a health-care challenge.

OBJECTIVE: To examine our experience with ANH and to determine the success of our postnatal follow-up program. STUDY DESIGN: Charts of mothers and infants seen (2004 to 2008) at our Regional Perinatal Center were reviewed retrospectively. ANH was defined during the third trimester by anterior pelvic diameters as follows: mild 7 to 9, moderate 10 to 14 or severe >or=15 mm. Fetuses with multicystic dysplastic kidney (MCDK) were included. RESULT: Screening of approximately 15 000 ultrasound (US) reports identified 268 fetuses with ANH. After prenatal US surveillance, 88 (33%) fetuses had resolved, while 180 (67%) required postnatal follow-up. These 180 fetuses were diagnosed with mild 38 (21%), moderate 83 (46%) and severe 19 (11%) ANH, uni or bilateral hydroureters 12 (7%), MCDK 19 (10%) and miscellaneous 9 (5%). Postnatal follow-up was successfully established for 75% of infants with hydroureters, 68% for those with MCDK and for 37% of infants with mild, 53% with moderate and 58% with severe ANH. Factors commonly known to influence compliance were not found more frequently among the 91 infants who were lost to follow-up. The only positive predictor for postnatal follow-up was a prenatal consultation with the pediatric urologist. CONCLUSION: Our antepartum program for diagnosis of ANH is accessible and efficient; however, there was an unacceptably high number of infants lost to follow-up. The absence of traditional barriers for compliance highlights the need to explore new ways of improving postnatal follow-up of infants with ANH.

Renal pelvis volume during diuresis in children with hydronephrosis: implications for diagnosing obstruction with diuretic renography.

PURPOSE: We measured the volume of the renal pelvis during diuretic renography (DR) in children with normal and hydronephrotic kidneys to determine if changes in pelvic volume could affect the accuracy of DR in diagnosing obstruction. MATERIALS AND METHODS: We studied 18 patients 1 month to 10 years old with unilateral hydronephrosis ultimately proved to be either obstructive or nonobstructive. Simultaneous DR and ultrasound were performed with patients supine using the gamma camera. Ultrasound measurements of the renal pelvis in 3 dimensions, obtained before and at intervals after diuretic injection, were used to calculate renal pelvic volume. The contralateral normal kidneys were used as controls. RESULTS: Between 15 and 60 minutes after diuretic injection the renal pelvis enlarged to a maximum volume in all hydronephrotic and normal kidneys and then gradually decreased in size. Mean average increase in volume for hydronephrotic kidneys ranged from 46% in obstructed kidneys to 88% in nonobstructed kidneys. Volume expansion caused dilution of isotope within the renal pelvis, which resulted in prolongation of elimination half-time (T1/2) in 42% of nonobstructed hydronephrotic kidneys sufficient to register an obstructed washout pattern. However, there were no differences in the initial pelvic volume or the rate or extent of increases or decreases in pelvic volume that would permit nonobstructed hydronephrotic kidneys to be distinguished from obstructed ones. CONCLUSIONS: The renal pelvis enlarges during diuresis in children with hydronephrosis. This enlargement causes dilution of isotope within the renal pelvis during DR, which prolonged the isotope washout rate or T1/2 sufficiently to produce an obstructed washout pattern in more than 40% of hydronephrotic kidneys that were ultimately proved to be nonobstructed. This misdiagnosis of obstruction is particularly likely to occur in children younger than 2 years because pelvic volume expansion is so exaggerated. Consequently, T1/2 appears to be particularly vulnerable to inaccuracy in diagnosing obstruction in this age group, and, therefore, it should not be relied on as an operative determinant.

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.

Percutaneous nephrostomy in children and adolescents: outpatient management.

PURPOSE: To determine if percutaneous nephrostomy can be performed safely as an outpatient procedure in children and adolescents. MATERIALS AND METHODS: Percutaneous nephrostomy was performed in 102 kidneys in 87 patients at 93 separate encounters. Patients were excluded from outpatient treatment if they presented with signs of infection, were hospitalized for other reasons, were undergoing additional endourologic stone procedures, had solitary kidneys or poor renal function, had social problems precluding outpatient care, or had a procedural complication. Follow-up was performed by means of direct communication and/or chart review. RESULTS: Successful outpatient percutaneous nephrostomy was performed in 39 (42%) of the 93 encounters. Reasons for exclusion included infection (n = 23), concomitant problems requiring hospitalization (n = 11), stone therapy (n = 7), solitary kidney with renal failure (n = 3), and social reasons (n = 10). No procedure-related complication occurred. No patient required readmission within 3 weeks for a tube- or procedure-related problem. CONCLUSION: Outpatient percutaneous nephrostomy can be safely performed in a selected group of patients.

Modification of the Koyanagi technique for the single stage repair of proximal hypospadias.

PURPOSE: We describe a modification of the Koyanagi technique for hypospadias. Use of opposing parameatal-based skin flaps that extend distally to incorporate the inner layer of the prepuce was modified to preserve blood supply to the flaps in an attempt to reduce complications and improve results. MATERIALS AND METHODS: During the last 7 years 20 boys underwent treatment of proximal hypospadias using the modified hypospadias repair. RESULTS: Cosmetic and functional, long-term (mean 34 months) results were excellent. Complications consisted of 4 urethrocutaneous fistulas (20%). There were no instances of meatal stenosis, diverticulum or urethral stricture. CONCLUSIONS: The modified technique permits 1-stage repair of proximal hypospadias with a low complication rate.

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.

Preoperative treatment with human chorionic gonadotropin in infancy decreases the severity of proximal hypospadias and chordee.

PURPOSE: We determined whether human chorionic gonadotropin (HCG) pretreatment of severe proximal penoscrotal hypospadias and chordee causes sufficient penile shaft or skin enlargement to enhance surgical repair and improve patient outcome. MATERIALS AND METHODS: A total of 12 boys 6 to 12 months old with proximal hypospadias and severe chordee received a course of HCG for 5 weeks immediately preceding hypospadias repair. RESULTS: Chordee decreased and penile length increased in all cases (mean increase 94%). Penile length gain was disproportional. Most of the increase in length was proximal to the urethral meatus, which moved the meatus distally an average of 11.4 mm. (range 6.0 to 19.0), producing a mean increase of 586% in the distance between the penoscrotal junction and meatus. In contrast, there was no statistically significant increase in penile shaft length distal to the urethral meatus. Surgical treatment was facilitated by HCG pretreatment. Three meatal based repairs were performed, only 1 urethral fistula developed and chordee was corrected by penile degloving only in 8 cases. CONCLUSIONS: HCG pretreatment in infancy produces disproportional penile enlargement, which advances the meatus distally to decrease the severity of hypospadias and chordee. This response pattern simplifies the required surgical procedure and appears to improve surgical results. It may benefit select patients, and provide insights into the endocrinopathy of hypospadias and the embryopathy of the hypospadias-chordee complex.

Long-term outcome of transurethral puncture of ectopic ureteroceles: initial success and late problems.

PURPOSE: We studied the long-term outcome of transurethral puncture of ectopic ureteroceles specifically associated with duplex systems. MATERIALS AND METHODS: We retrospectively reviewed the records of patients who underwent transurethral puncture of an ectopic ureterocele. Study exclusion criteria were orthotopic, bilateral and prolapsing ureteroceles. RESULTS: We identified 19 girls and 2 boys, of whom 11 presented with prenatal hydronephrosis and 10 presented with urinary tract infection. Mean age at puncture was 5 months (range 0.5 to 60). Preoperatively voiding cystourethrography revealed no reflux in 7 patients, isolated ipsilateral lower pole reflux in 8, and bilateral and/or contralateral reflux in 6. Postoperatively studies initially showed no reflux in 8 cases but in 4 of the 8 reflux recurred up to 4 years after puncture. In 10 patients (48%) reflux developed into the ureterocele and upper pole segment. Repeat puncture was required 1 to 13 months after the initial procedure in 4 patients for persistent or recurrent upper pole hydroureteronephrosis. Subsequent open surgery was required in 15 of the 21 cases (71%), including ureterocele excision with ureteral reimplantation in 14. Of the children 10 and 4 underwent open surgery for recurrent urinary tract infection and progressive reflux, respectively, while 1 underwent ureteroureterostomy for progressive upper pole reflux. No patient underwent upper pole nephrectomy. Of the remaining 6 patients 4 have low grade reflux. CONCLUSIONS: Transurethral puncture of ectopic ureteroceles provides effective short-term correction of upper pole obstruction but it is not definitive therapy in the majority of cases. Most children still require open surgery. In patients without reflux after the puncture procedure new onset, recurrent or progressive reflux may later develop with extended followup. Repeat puncture may be required to ensure adequate decompression in a minority of cases, as in the 20% in our series.

Strategies for managing upper tract calculi in young children.

PURPOSE: Pediatric urolithiasis is relatively uncommon and there is little information on the application of modern surgical procedures in young children. We present a single center experience with the surgical management of upper tract calculi in this age group. MATERIALS AND METHODS: We reviewed presentation, co-morbidity, treatment, outcome and complications in all prepubertal patients who required surgical treatment for ureteral or renal calculi during a 4-year period. The series consists of 24 girls and 17 boys 17 months to 14 years old (mean age 7.5 years). A total of 26 children were anatomically normal, and 4 had myelomeningocele, 4 had ureteropelvic junction obstruction (in a pelvic kidney in 1), 2 had cloacal anomalies, 2 had vesicoureteral reflux, and 1 each had nonrefluxing megaureter, orthotopic ureterocele and a functioning renal transplant. RESULTS: Extracorporeal shock wave lithotripsy was performed in 24 patients. Stents or nephrostomy tubes were only used in the 4 patients who presented with pyonephrosis. Of the 41 cases 17 were rendered stone-free, 3 had a decreased stone burden and 4 were failures. Ureteroscopic extraction of distal ureteral calculi was successful in 11 of 12 children, of whom the youngest was 2.5 years old. No child had postoperative infection or evidence of ureteral obstruction. Stent placement facilitated stone passage or dissolution in 2 patients, a renal calculus was percutaneously extracted in 2 and 7 required open surgery, mostly for correcting simultaneous anatomical abnormalities or after minimally invasive surgery failed. Some metabolic abnormality was detected in 80% of the children tested. CONCLUSIONS: The surgical management of upper urinary tract calculi in young children parallels that in adults. Minimally invasive surgical methods may be safely used even in young infants. Most children do not need elective stenting before lithotripsy. Open procedures are still required in 17% of cases. The majority of children have definable metabolic abnormalities.

Postneonatal circumcision with local anesthesia: a cost-effective alternative.

PURPOSE: Despite the controversy regarding the need for routine neonatal circumcision, most boys in the United States are circumcised. Physicians are commonly asked to perform circumcision after the neonatal period and are often unaware of the cost factors related to the timing and location of postneonatal circumcision. MATERIALS AND METHODS: We describe the medical and financial advantages of postneonatal circumcision with local versus general anesthesia. RESULTS: During a 30-month period 245 boys 6 months to 15 years old underwent circumcision under general anesthesia in the operating room. Hospital charges (facility and equipment) averaged $1,555 and anesthesia charges averaged $250. Therefore, the average cost for circumcision in the operating room was $1,805. During the same time period 287 infants 3 days to 9 months old (20% older than 3 months) underwent circumcision under local anesthesia in an office setting. The facility and equipment charge for these office procedures averaged $196. Overall, approximately $461,783 were saved in this 30-month period ($184,713 annually) by performing circumcision with local anesthesia in an office setting rather then in the operating room with general anesthesia. There was no significant difference in complication rates between the local and general anesthesia groups (1.4 versus 1.6%). CONCLUSIONS: Circumcision with local anesthesia can be performed easily and safely during the first several months of life and has many advantages. Parents prefer this method because it is more convenient and eliminates the risk of general anesthesia. The enormous cost savings using local as opposed to general anesthesia should prompt a reexamination of the location and timing of postneonatal circumcision.

[The prenatal diagnosis of hydronephrosis: when and why NOT to operate?]. / Diagnóstico prenatal de la hidronefrosis: cuándo y por qué NO operar?

OBJECTIVES: To determine the proper timing and indications for pyeloplasty in infants with prenatally diagnosed unilateral hydronephrosis. METHODS: Examination of the 1) biological features of hydronephrosis which are unique to the newborn, 2) natural history of non-operated newborn hydronephrosis, and 3) accuracy of tests which assess obstruction in hydronephrosis. RESULTS: Prenatally diagnosed unilateral hydronephrosis is a benign disease in most infants because obstruction is not present: the hydronephrosis will improve or disappear spontaneously, and impaired renal function will improve or normal renal function will remain stable. Consequently surgical treatment is not indicated; it will neither hasten nor improve the outcome. Unfortunately, the conventional tests for assessing obstruction are invalid in the infant and obstruction must be diagnosed or excluded by newly described protocols which use serial measurement of pelvic dilation, differential renal function and renal size. CONCLUSION: UPJ obstruction presents a diagnostic but not a therapeutic dilemma in infancy. True UPJ obstruction should be operated upon as soon after birth as possible to prevent renal deterioration. However, over 85% of infants with prenatally diagnosed hydronephrosis do not have a true obstruction and do not require surgery; they will improve spontaneously. The difficulty in deciding which patients require surgery can be minimized by a careful diagnostic protocol.

The relationship among dysfunctional elimination syndromes, primary vesicoureteral reflux and urinary tract infections in children.

PURPOSE: We determine whether functional bladder and/or bowel disorders influence the natural history or treatment of children with primary vesicoureteral reflux. MATERIALS AND METHODS: We assessed 143 children with primary vesicoureteral reflux that stopped spontaneously or was surgically corrected for functional bowel and/or bladder disorders, including bladder instability, constipation and infrequent voiding, termed the dysfunctional elimination syndromes. RESULTS: Dysfunctional elimination syndromes were present in 66 of 143 children (43%) thought to have primary vesicoureteral reflux. Of these 66 patients 54 (82%) had a breakthrough urinary tract infection and underwent reimplantation compared to only 18% without the syndromes. Of 70 children who had a breakthrough urinary tract infection dysfunctional elimination syndromes were present in 54 (77%) and absent in 16 (23%). Of the remaining 73 patients who did not have a breakthrough infection dysfunctional elimination syndromes were present in 12 (16%) and absent in 61 (84%). In children with dysfunctional elimination syndromes the resolution of reflux that was 1 grade less severe required an average of 1.6 years longer. After the disappearance of reflux, urinary tract infection developed in 18 children, including 14 (78%) with dysfunctional elimination syndromes. Unsuccessful surgical outcomes involving persistent, recurrent and contralateral reflux occurred only in children with dysfunctional elimination syndromes. CONCLUSIONS: Dysfunctional elimination syndromes are common and are often unrecognized in children with primary reflux. These syndromes are associated with delayed reflux resolution and an increased rate of breakthrough urinary tract infection, which leads to reimplantation surgery. Dysfunctional elimination syndromes also adversely affect the results of reimplantation and represent a risk for recurrent urinary tract infection after reflux resolves. The evaluation and management of dysfunctional elimination syndromes should be an integral part of the treatment of every child with vesicoureteral reflux. Effective evaluation and treatment may be made cost-effective by decreasing the followup, the number of breakthrough urinary tract infections and the number of children requiring reimplantation.

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.

Cystic dysplasia of the rete testis: a benign congenital lesion associated with ipsilateral urological anomalies.

PURPOSE: Cystic dysplasia of the rete testis is a benign congenital lesion that can mimic testicular cancer. We report 6 cases, review the literature, discuss the embryological etiology and make management recommendations. MATERIALS AND METHODS: The records and pathology reports of 6 boys presenting with cystic dysplasia of the rete testis at 5 institutions were reviewed, as was the relevant literature. RESULTS: Of the 6 cases 5 presented as scrotal masses in previously healthy boys and 1 as an abdominal mass in a newborn with multiple congenital anomalies. One patient had been followed from birth for a multicystic dysplastic kidney and 4 were found to have an ipsilateral absent kidney during evaluation. Development of the contralateral side was normal in most cases. CONCLUSIONS: Cystic dysplasia of the rete testis is an unusual, benign congenital lesion that can mimic testicular cancer in presentation. The presence of ipsilateral renal anomalies, particularly renal agenesis, can suggest cystic dysplasia of the rete testis in the differential diagnosis preoperatively. Even if cystic dysplasia of the rete testis is suspected, we recommend inguinal exploration and early control of the spermatic cord in the event that neoplasia is identified. If possible, the goal of preserving as much normal testicular parenchyma as possible is desirable. Long-term followup for possible recurrence is recommended, particularly after local excision.

Cure of nocturnal enuresis: why isn't desmopressin very effective?

Prospective controlled studies on the treatment of enuresis with desmopressin (DDAVP) indicate that cure rates (complete dryness) while on therapy are markedly lower than are response rates (decrease in wet nights). In an attempt to explain this discrepancy, we analyzed the etiological mechanisms for enuresis and found evidence that most children are not cured by DDAVP because their nocturnal wetting is not actually caused by the defect which DDAVP therapy aims to cure: low nocturnal vasopressin secretion with high nocturnal urinary output. Our study suggested that an arrest in the normal development of two separate areas of the central nervous system is necessary for enuresis to occur in many patients, yet cure of enuresis occurs if either developmental delay is eliminated. This hypothesis of a dual developmental delay helps to unify many diverse and often seemingly contradictory scientific observations about this condition and to explain why many patients react inconsistently to treatment aimed at a single etiology, yet eventually become dry.

Treatment of high undescended testes by low spermatic vessel ligation: an alternative to the Fowler-Stephens technique.

PURPOSE: We determined whether testis viability after a Fowler-Stephens orchiopexy depends on ligating the spermatic vessels high and far proximal to the undescended testis. MATERIALS AND METHODS: Based on studies of testicular vascular anatomy we developed a technique of low spermatic vessel ligation and performed it on 39 high undescended testes in 33 patients. RESULTS: Testis viability was 97% at 1 month and 93% (25 of 27) at 1 year. CONCLUSIONS: Ligation of the spermatic vessels does not need to be performed high to ensure testis viability. Testicular vascular anatomy supports low spermatic vessel ligation and by decreasing tension on the testis low spermatic vessel ligation may enhance viability. A 2-stage laparoscopic approach to the high undescended testis is difficult to justify on the basis of cost or outcome analysis.

The renal vascular response to acutely elevated intrapelvic pressure: resistive index measurements in experimental urinary obstruction.

PURPOSE: To assess the accuracy of resistive index (RI) in the diagnosis of obstruction. MATERIALS AND METHODS: The time course of RI and its relationship to intrapelvic pressure were measured in 6 dogs following unilateral obstruction. RESULTS: Changes in RI 1) occurred as early as 1/2 hour after acute obstruction, 2) only reached diagnostic sensitivity after 3 to 4 hours, 3) accurately diagnosed obstruction whenever the RI ratio between the kidneys exceeded 1.15 and 4) were uninfluenced by alterations in intrapelvic pressure. CONCLUSIONS: Because RI more closely reflects changes in renal blood flow than pelvic pressure, it can accurately diagnose acute obstruction but only after several hours. Diagnostic accuracy in chronic obstruction may be influenced by these physiologic relationships.

Diagnostic criteria for assessing obstruction in the newborn with unilateral hydronephrosis using the renal growth-renal function chart.

Previous studies in newborns with unilateral hydronephrosis demonstrated that the contralateral normal kidney can rapidly compensate for changes in function in the hydronephrotic kidney by increasing or decreasing its growth rate. To formulate diagnostic criteria for assessing obstruction using compensatory growth responses we developed a renal growth-renal function chart that graphically describes the normal renal growth rate in young children. This chart allows changes in function in the hydronephrotic kidney to be graphically compared to changes in length of the contralateral normal kidney. The renal growth-renal function chart was used to assess obstruction in 47 neonates with primary unilateral hydronephrosis. Four reproducible, clinically relevant diagnostic patterns of differential function and growth were identified: 1) obstruction, 2) corrected obstruction, 3) no obstruction with good differential function (greater than 40%) and 4) no obstruction but poor differential function (less than 40%). The renal growth-renal function chart helped to identify and exclude obstruction, and provided welcome reassurance that nonobstructive hydronephrosis was not harming the kidney. It appears to have potential for improving diagnostic accuracy in newborns with hydronephrosis.