The case for immediate pyeloplasty in the neonate with ureteropelvic junction obstruction

Factors Accountable for Unabated Obstruction Following Pyeloplasty

Purpose:

Split renal function (SFR) and frusemide washout (FWO) are assessed by the DTPA renogram to measure the renal parenchymal functions as well as the evidence of obstruction, both for diagnosis and to treat the pelviureteric junction obstruction. In good number of renal units, both these parameters remain unaltered even after surgery and cause anguish to parents and referring physicians and are usually attributed toward “defective pyeloplasty.” In this study, we have tried to single out the bona fide responsible factor for the bad outcome; either the nonreversible kidney or the restenosis of pyeloplasty.

Patients and Methods:

We studied file of 69 patients in whom a double “J” (DJ) stent was left in situ for internal drainage for a duration of 8 weeks in the postoperative period. DTPA scans were performed preoperative, at 8 weeks with a stent in place, and at 12 and 24 months postremoval of the stent to assess renal function.

Results:

In our study, 45 patients (65.2%) showed improvement either in SRF or in FWO or in both after 8 weeks following pyeloplasty and 24 of 69 units (34.8%) did not show any change in renal function with DJ stent in place. Only in six units (8.7%), out of 69 units had deterioration of renal function after removal of DJ stent.

Conclusions:

In our opinion, no improvement of renal function found in 24 units (34.8%) even with internal drainage with DJ indicates irreversible renal damage. In 45 units (65.2%), renal function reversed after pyeloplasty and DJ stent. However, after the removal of the DJ, functions deteriorated in six units (8.7%) due to restenosis following pyeloplasties.

Color Doppler Ultrasonography in Evaluating the Outcomes of Pyeloplasty in Ureteropelvic Junction Obstruction

Purpose

To evaluate the accuracy of Color Doppler ultrasonography for diagnosing post pyeloplasty elimination of obstruction in Ureteropelvic Junction Obstruction patients.

Methodology

Patients with the diagnosis of UPJO enrolled in the study and underwent open pyeloplasty. Three to 6 months after the operation, patients were recalled and underwent isotope scan as the gold standard test and renal color Doppler ultrasonography to assess the success rate of pyeloplasty.

Results

A total of 39 patients were evaluated and analyzed. The average follow-up time for patients was 9.1 months. The success rate of surgery in the study population was 100%. The mean RI of the affected side before the operation was 0.69 ± 0.01 and after the pyeloplasty, it reached to 0.65 ± 0.01. The difference between the mean RI of the affected side before and after the operation is 0.04 (P < 0.001). Age, type and severity of obstruction and the technique of surgery did not have any impact on these parameters. The difference between the RI of the affected and healthy side was termed ΔRI. ΔRI before and after the operation was 0.084 and 0.014, respectively. The decrease of ΔRI in the case of pyeloplasty is 0.07 on average (P < 0.001), which can be predicted for pyeloplasty success.

Discussion

Color Doppler ultrasonography can be used as a non-invasive, fast, non-expensive, and available modality for evaluating the outcome of pyeloplasty instead of the nuclear scan or IVP.

Diuresis renography in the evaluation and management of pediatric hydronephrosis: What have we learned?

Diuresis renography (DR) is widely used in the evaluation of hydronephrosis and hydroureter in infants and children. The goal of this provocative nuclear imaging examination should be to detect the hydronephrotic kidneys at risk for loss of function and development of pain, hematuria, and urinary tract infection. The reliability of DR is dependent on the acquisition and processing of the data as well as interpretation and utilization of the results. In this review, the key concepts of standardized DR and pitfalls to avoid are highlighted.

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.

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.

Is it Always Necessary to Treat an Asymptomatic Hydronephrosis Due to Ureteropelvic Junction Obstruction?

The postnatal treatment of asymptomatic unilateral hydronephrosis due to ureteropelvic junction obstruction remains controversial, and the timing of and indications for surgical intervention are continuously debated. There is no consensus on the best follow-up during expectant management. The various modalities and parameters have been discussed along with their pros and cons and an attempt has been made to clear up the controversies.

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.

Early experience of using transumbilical multi-stab laparoscopic pyeloplasty for infants younger than 3 months

OBJECTIVE

Minimally invasive surgery is increasingly being adopted in pediatric urology practice. The aim of this study is to investigate the feasibility and the safety of transumbilical multi-stab laparoscopic pyeloplasty (TMLP) as a treatment for infants younger than 3 months with severe hydronephrosis.

METHODS

We retrospectively reviewed 63 infants younger than 3 months with severe hydronephrosis who underwent TMLP from June 2010 to March 2013. The operative indications included: 1) prenatal diagnosis of hydronephrosis with anteroposterior renal pelvic diameter greater than 3 cm and Society of Fetal Urology (SFU) Grade 4 hydronephrosis; 2) ipsilateral differential renal function being less than 40%. Patients were followed up with physical examinations, ultrasound and radionuclide scans.

RESULTS

The operations were successfully performed in all 63 patients. There was no conversion, no requirement of additional trocar placement and no intraoperative complication. The median age was 54 (47-87) days. The median operative time was 75 (53-118) minutes. The patients were followed up for 12 (6-36) months. The anastomoses were proved to be patent and the renal parenchymal thickness increased. The renal pelvic anteroposterior diameters were reduced and the renal functions were improved (p < 0.01). In addition, the scars were barely noticeable.

CONCLUSIONS

TMLP for infants younger than 3 months with severe hydronephrosis is feasible, safe and minimally invasive. The cosmetic results are excellent.

Long term outcome of management of antenatally diagnosed pelvi-ureteric junction obstruction

OBJECTIVE

To evaluate the outcome of children with antenatally detected unilateral pelvi-ureteric junction obstruction (PUJO).

METHODS

Children with antenatally diagnosed hydronephrosis, postnatally, unequivocally proven to be due to PUJO, with a normal contralateral kidney were evaluated. Children with atleast 2 y of follow-up were included in the study. The children were divided into early pyeloplasty (those who underwent pyeloplasty at presentation) and conservative (who were managed conservatively). Children in conservative group, who required pyeloplasty during follow up, constituted the delayed pyeloplasty group and those who are still being managed conservatively constituted the no surgery group. The outcome was compared in between these groups in terms of relative function of the affected kidney, drainage pattern and pelvicalyceal dilatation.

RESULTS

A total of 30 children with a mean follow up of 43.3 mon were enrolled in the study. Of the 30 patients, ten had undergone early pyeloplasty and the remaining 20 were managed conservatively. Of these 20, 8 had undergone delayed pyeloplasty and the remaining 12 constituted no surgery group. Overall, 40% of patients in the present study had not required pyeloplasty till the end of the study period. The renal function in early pyeloplasty and conservative group was maintained or improved. Delayed pyeloplasty was able to restore the function in those operated for fall in function to the level that was seen at presentation. The change in renal function in between the early and delayed pyeloplasty groups was not statistically significant (p 0.97).

CONCLUSIONS

The conservative management of PUJO, in renal unit with good function, does not lead to any significant deterioration in the function even when delayed pyeloplasty is performed, when indicated. Two-fifths of the patients may not require pyeloplasty at all.

Urinary biomarkers in prenatally diagnosed unilateral hydronephrosis

The introduction of prenatal ultrasonography as a screening method entails an increasing number of infants diagnosed with prenatal hydronephrosis. Ureteropelvic junction obstruction accounts for 35% of prenatal hydronephrotic cases. Urinary tract obstruction that occurs during early kidney development affects renal morphogenesis, maturation and growth, and in the most severe cases this will ultimately cause renal insufficiency. A major challenge in the clinical management of these patients is to preserve renal function by selection of the 15%-20% who require early surgical intervention, leaving those for whom watchful waiting may be appropriate because of spontaneous resolution/stabilization without significant loss of renal function. Today, this requires medical surveillance, including repetitive invasive diuretic renograms relying on arbitrary threshold values, and therefore there is a need for non-arbitrary, non-invasive urinary biomarkers that may be used as predictors for renal structural changes and/or decreasing renal function, and thereby provide the surgeon with more clear indications for surgical intervention. In this review, we summarize the currently well-known facts about urinary biomarkers in ureteropelvic junction obstruction concerning renal function, and we also suggest potential novel urinary biomarkers.

Management of severe bilateral ureteropelvic junction obstruction in neonates with prenatally diagnosed bilateral hydronephrosis

PURPOSE

The management of prenatally detected bilateral ureteropelvic junction obstruction (UPJO) remains controversial. We attempted to develop a treatment plan for patients with severe bilateral UPJO.

MATERIALS AND METHODS

We evaluated the records of 13 patients with prenatally diagnosed grade 3 or more bilateral hydronephrosis that led to the postnatal diagnosis of severe bilateral UPJO. Ultrasonography and (99m)technetium mercaptoacetyltriglycine ((99m)Tc-MAG3) renal scans were performed within 1 month. Four renal units had grade 3 and 22 had grade 4 hydronephrosis. All 13 patients were managed by unilateral pyeloplasty, and the patients' mean age was 3 months. At 1 month postoperatively, we decided whether delayed surgery in the opposite renal unit was necessary according to the findings of ultrasonography and (99m)Tc-MAG3 scans.

RESULTS

Of 13 patients, 11 underwent initial pyeloplasty on renal units with more severe hydronephrosis or lower relative renal function (RRF) on (99m)Tc-MAG3 scans. The remaining 2 patients simultaneously underwent percutaneous nephrostomy on renal units with a lower RRF and initial pyeloplasty on renal units with a higher RRF. In 5 patients, contralateral hydronephrosis had spontaneously improved at 1 month postoperatively, and 8 patients underwent delayed contralateral pyeloplasty at 2 months postoperatively.

CONCLUSIONS

In children with severe bilateral UPJO, the non-operated renal units with grade 3 and some with grade 4 hydronephrosis improved spontaneously after unilateral pyeloplasty. Therefore, delayed pyeloplasty of the opposite side should be considered at 1 month following initial pyeloplasty.

Prenatal management of urogenital disorders

Antenatal sonography has markedly increased the detection of urogenital anomalies, including those conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder outlet obstruction but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida, can be corrected in utero, with improvements in hydrocephalus seen along with a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally now possible. As further techniques evolve to correct underlying disease processes, it becomes important to critically assess the therapies, particularly with long-term outcome data.

[Experience with laparoscopic pyeloplasty for treating ureteropelvic junction obstruction in children. Technique and results]

INTRODUCTION

Open pyeloplasty has been the gold standard for treating ureteropelvic junction obstruction, with a success rate greater than 90%. However, during the last decade the management has been revolutionized with the introduction of laparoscopy and endourology, yielding comparable results and fewer morbid outcomes.

MATERIALS AND METHODS

Between 1997 and 2007, dismembered and non-dismembered retroperitoneoscopic pyeloplasty was performed in 31 children with a medium age of 123 months (range 36-192 months). Fourteen children underwent dismembered pyeloplasty (Anderson-Hynes) and 16 children underwent non-dismembered pyeloplasty (YV plasty) and in one child we performed an ureterolysis.

RESULTS

The mean operating time was 120 min (range 67-257 min). In 21 cases, intraoperative findings revealed a significant crossing vessel. Based on a furosemide nephrogram and subjective complaints, the success rate was 93%. The two failures (laparoscopic YV plasty and laparoscopic ureterolysis) occurred in the early phase of laparoscopy and have been treated by open Anderson-Hynes plasty.

CONCLUSION

With increasing improvement of the suture techniques, laparoscopic pyeloplasty represents, in experienced hands, an alternative method with success rates comparable to the open technique. In our opinion, retroperitoneoscopic pyeloplasty is technically possible and feasible even in infants.

International Scientific Committee of Radionuclides in Nephrourology (ISCORN) consensus on renal transit time measurements

This report is the conclusion of the international consensus committee on renal transit time (subcommittee of the International Scientific Committee of Radionuclides in Nephrourology) and provides recommendations on measurement, normal values, and analysis of clinical utility. Transit time is the time that a tracer remains within the kidney or within a part of the kidney (eg, parenchymal transit time). It can be obtained from a dynamic renogram and a vascular input acquired in standardized conditions by a deconvolution process. Alternatively to transit time measurement, simpler indices were proposed, such as time of maximum, normalized residual activity or renal output efficiency. Transit time has been mainly used in urinary obstruction, renal artery stenosis, or renovascular hypertension and renal transplant. Despite a large amount of published data on obstruction, only the value of normal transit is established. The value of delayed transit remains controversial, probably due to lack of a gold standard for obstruction. Transit time measurements are useful to diagnose renovascular hypertension, as are some of the simpler indices. The committee recommends further collaborative trials.

Congenital urinary tract obstruction

Congenital urinary tract obstruction is a heterogenous condition with a varying natural history. Accurate diagnosis within the late-first and second trimesters allows for counselling of the parents and planning of multi-disciplinary care for the pregnancy and newborn. Antenatal investigations to predict postnatal renal function are of varying accuracy. However, some factors have been shown to be predictive of poor outcome in terms of renal function at birth and infancy. There is the possibility of in-utero intervention in these fetuses.

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.

Micturating cystourethrograms are not necessary for all cases of antenatally diagnosed hydronephrosis

OBJECTIVE

Since 1995 we have, at our centre, adopted a selective approach to performing micturating cystourethrograms (MCUGs) on patients with antenatally diagnosed hydronephrosis. This study reviews the outcome of this policy.

METHODS

We carry out MCUGs only if any of the following features are present on ultrasound: bilateral hydronephrosis, ureteric dilatation, renal scarring, bladder wall thickness greater than 5mm, or presence of a duplex system or ureterocele. Patients with simple unilateral hydronephrosis are excluded, and are managed with 6 months' trimethoprim prophylaxis and ultrasound surveillance with a minimum of 3 years' follow up.

RESULTS

Fifty-five patients were referred with an antenatal diagnosis of hydronephrosis between 1999 and 2002; 26 (47%) did not have an MCUG. Of these, five had increasing hydronephrosis and required surgery for pelvi-ureteric junction obstruction, and three had a multicystic dysplastic kidney on postnatal scanning. In the remaining 18 patients, the hydronephrosis resolved spontaneously, with no renal scars or asymmetry. During follow up, none of these patients had a urinary tract infection.

CONCLUSION

We believe that vesico-ureteric reflux in most antenatally diagnosed hydronephrotic kidneys is physiological rather than pathological, and resolves with time without causing long-term renal damage. This is a separate entity from, rather than a precursor of, the pathological symptomatic refluxing kidney in older, mainly female children. Taking a more conservative approach to the postnatal investigation of antenatally diagnosed hydronephrotic kidneys has not resulted in any missed damaged kidneys, but has reduced the number of invasive investigations performed. A careful protocol and detailed postnatal ultrasonography are important to prevent missed pathological cases.

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.

The prognostic value of relative renal function greater than 51% in the pelvi-ureteric junction-obstructed kidney on 99mtechnetium mercaptoacetyltriglycine study

OBJECTIVE

Obstructed kidneys with relative function (RRF) estimates >50% are occasionally noted in (99m)technetium mercaptoacetyltriglycine renal studies. It is thought that increased RRF might confer some benefit and/or permit delayed intervention. We compared the RRF and absolute renal function, as defined by effective renal plasma flow (ERPF), of obstructed kidneys in the ranges >51%, 40%-50% and <40% RRF before and after pyeloplasty.

METHODS

Twenty children, median age 13.5 months (range 3 weeks-126 months), satisfied criteria for the diagnosis of PUJ obstruction and estimated function >51% (group 1). Their pre- and post-intervention data were compared with 21 children, median age 2 months (range 1 week-126 months), with PUJ obstruction and 40%-50% RRF (group 2); and 21, median age 6 months (range two days-110 months), with RRF below 40% (group 3). Kidneys showing signs of continuing obstruction after surgery were excluded.

RESULTS

Final ERPF was negatively related to age: younger children, and those with a higher preoperative ERPF, recovered better than older children and those with a lower ERPF (p<0.05). Pre- and postoperative mean ERPF in group 1 was 76 (range 21-203) and 102 (6-240) ml/min/1.73 msq respectively. In group 2, these values were 75.2 (30-187) and 130.9 (44-306) ml/min/1.73 msq, and they were 42.6 (5-179) and 80.2 (17-205) ml/min/1.73 msq in group 3. When adjustment was made for preoperative ERPF, there was no evidence that RRF grouping was related to ERPF outcome. The postoperative ERPF of seven of 20 kidneys from group 1 (>51%) was lower than the ERPF before surgery compared to 2/21 in group 2 and 4/21 in group 3, but these differences were not statistically significant (p=0.25).

CONCLUSIONS

Most kidneys in each functional range improved when obstruction was relieved. An RRF >51% in the obstructed kidney was not always prognostically beneficial, and may be a warning of impending decompensation in a minority.

Repair of adult ureteropelvic junction obstruction in the solitary kidney: effect on renal function

OBJECTIVES

To evaluate the effect of pyeloplasty for the treatment of ureteropelvic junction (UPJ) obstruction on adult renal function in the setting of a solitary kidney.

METHODS

Since 1989, 312 patients have undergone operative intervention for UPJ obstruction. Of these, 13 patients (5 men and 8 women), aged 17 to 76 years (median 44.5), had a solitary kidney and were available for postoperative surveillance. Treatment consisted of endopyelotomy (n = 3), laparoscopic dismembered pyeloplasty (n = 3), and open dismembered pyeloplasty (n = 9). Two patients underwent two separate interventions for UPJ obstruction repair. Success was defined as symptomatic relief and radiographic resolution at the latest follow-up visit. In all patients, serum creatinine, estimated glomerular filtration rate, and weight were measured preoperatively, postoperatively, and at all follow-up examinations. Statistical analysis was performed to analyze group differences using the Wilcoxon signed-rank test.

RESULTS

The median follow-up was 22 months (range 2 to 96). Three patients experienced a treatment failure and were excluded from the analysis. At the latest follow-up visit, the postoperative serum creatinine had improved by a median of 0.6 mg/dL (range -0.2 to 6.3; P <0.0001), and postoperative estimated glomerular filtration rate had improved by a median of 24.4 mL/min (range -13.9 to 66; P <0.0001). No statistically significant difference in renal function was observed between the patients' first and last follow-up visits.

CONCLUSIONS

Operative intervention for the treatment of adult UPJ obstruction may result in symptomatic relief and, perhaps more importantly, renal functional improvement. These findings are important for effectively counseling patients and considering indications for intervention.

Postnatal management of antenatally diagnosed ureteropelvic junction obstruction

OBJECTIVE

The management of antenatally diagnosed ureteropelvic junction obstruction (PUJO) is controversial. Here, we present our experience over a period of 13 years and discuss our management protocol.

MATERIALS AND METHODS

We reviewed the files of 234 patients with antenatally diagnosed congenital hydronephrosis due to PUJO. Management was tailored to each patient, based on a combination of diethylenetetraminepentacetic acid renogram outcome, pelvic diameter, as well as the patient's symptoms.

RESULTS

Pyeloplasty was carried out early in 52 kidneys. Of the total, 182 patients were managed expectantly. Out of these, 45 underwent delayed pyeloplasty. The remaining 137 patients (189 units) were managed non-operatively. In patients who underwent early pyeloplasty, the mean split differential renal function was 37% before and 40.05% after surgery. In those with delayed intervention, the mean renal function was 37.8% before and 42.2% after surgery. In patients who did not have surgery, the mean differential renal function was 45.7% initially and 48.2% at the last accepted follow up. The overall operative success rate was 97.9%.

CONCLUSION

We believe that pyeloplasty is the proper treatment for babies with congenital PUJO and <40% split differential function and/or pelvic diameter >35 mm at the initial visit. In other patients a period of observation is warranted, and pyeloplasty should be carried out only if their kidney function deteriorates or the renogram curve does not show improvement. With the excellent results of pyeloplasty we believe that a safer approach is to operate on more kidneys rather than risk of losing valuable kidney function.

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.

Moderate approach to the antenatally diagnosed unilateral ureteropelvic junction obstruction: experience with 93 patients

To evaluate the results of the treatment in patients with antenatally detected unilateral ureteropelvic junction obstruction. Ninety-three patients were analyzed according to the radiologic and scintigraphic findings and mode of the treatment. Fifty-eight patients were treated surgically while 29 patients were followed conservatively. All patients were reevaluated at the first year of the treatment with diuretic renogram (DR). Follow-up procedure was finished at first postoperative year in surgically treated patients, while mean follow-up duration was 14.9+/-6.9 months for the conservatively treated group. In the operated group, pelvic diameter was greater than 20 mm on ultrasound and overall rate of mean split renal function was 38.65+/-9.55% on DR and 39.65+/-12.55% at first postoperative year. In the conservatively treated group, mean split renal function was 46.17+/-3.42 at the beginning and 47.48+/-4.00 at first year of follow-up. Sixty-three percent of the patients underwent pyeloplasty while 83% of them were showing obstructive pattern on DR. We believed that surgery should be done in renal units which showed pelvic diameter greater than 20 mm and less than 40% of split renal function, while others might be followed conservatively, with or without an obstructive pattern on DR.

Congenital midureteral stricture in children diagnosed with antenatal hydronephrosis

OBJECTIVES

Antenatal hydronephrosis is the most common genitourinary pathologic finding during gestational ultrasonography. Congenital midureteral strictures are an unusual cause of prenatal hydronephrosis, with 13 total previously reported and only 1 diagnosed as a result of antenatal ultrasonography.

METHODS

We present 4 cases of midureteral strictures as the cause of antenatal hydronephrosis and review the published data on congenital midureteral obstruction.

RESULTS

All midureteral strictures in our series and in the published reports were treated surgically after varying periods of observation. Retrograde pyelography was diagnostic in all cases.

CONCLUSIONS

This atypical cause of antenatal hydronephrosis may provide additional insight into the controversy regarding preoperative retrograde pyelography before surgical intervention for ureteropelvic junction obstruction. Given the typical misdiagnosis of ureteropelvic junction obstruction in the setting of midureteral stricture disease, we believe that the threshold for retrograde pyelography should be very low.

Differential renal function in the prediction of recovery in adult obstructed kidneys after pyeloplasty

AIM

Pyeloplasty is a widely accepted method for the treatment of ureteropelvic junction obstruction (UPJO). Surgery has long been thought to affect postoperative renal function. However, controversies still exist on the functional studies that can be used to indicate which renal units will benefit from surgery. In this study, the correlation between differential renal function (DRF) and other preoperative parameters was examined to determine which parameter more accurately predicts recovery of renal function in adult obstructed kidneys.

MATERIALS & METHODS

In this study, the authors evaluated 32 patients with UPJO. In all patients, standart diuretic Tc-99m DTPA renal scans were performed preoperatively and 6 months after surgery. Patients were divided into two groups according to the preoperative DRF (> or = 30%, n = 22, group I and < 30%, n = 10, group II). Second type classification was made according to the postoperative DRF improvement as improved (group A, n = 13) and not improved (group B, n = 19). These groups were then compared regard to variables which were defined as symptoms, age at operation and ultrasonographic findings. We also evalulated whether preoperative parenchymal function is important to predict improvement in drainage half-time (T1/2).

RESULTS

While preoperative drainage half-time was 39.6 +/- 15.9 minutes, postoperative half-time decreased to 16.9 +/- 6.8 minutes (p < 0.001). The mean DRF did not improved significantly after surgery compared with preoperative values (32.03 +/- 9.42% versus 36.16 +/- 9.60%). When comparing the patients with preoperative DRF > or = 30% (group I, DRF 38 +/- 0.8%) to those who had an initial DRF below 30% (group II, DRF 22.8 +/- 5.2%), postoperative DRF was 41.22 +/- 5.72 in group I and 25.00 +/- 6.22 in group II. The difference was significant (p < 0.01). The patients in group I and II showed improvement in 50% and 20%, respectively. Age, clinical presentation and ultrasonographic findings did not affect functional outcome after pyeloplasty. We could not find any correlation between preoperative DRF and the degree of improvement in T1/2.

CONCLUSION

Renal function improves after pyeloplasty with regard to the initial level of split renal function in adult obstructed kidneys. Improvement may not be observed especially in patients with DRF less than 30%.

Prenatal management of urogenital disorders

Antenatal sonography has increased the detection of urogenital anomalies markedly, including conditions that lead to significant morbidity and mortality. Prenatal intervention is feasible to arrest and sometimes reverse the sequelae of bladder-outlet obstruction, but not necessarily renal damage. Myelomeningoceles, the most severe form of spina bifida,can be corrected in utero, with improvements in hydrocephalus and a decreased incidence of ventricular shunting postnatally. Medical therapy to prevent virilization associated with congenital adrenal hyperplasia has been successful, with improved ability to detect its presence prenatally. As techniques evolve to correct underlying disease processes,it becomes important to assess the therapies critically, particularly with long-term outcome data.

Upper urinary tract: when is obstruction obstruction?

PURPOSE OF REVIEW

Obstruction can either be defined as a condition that hampers optimal renal development, or, more conservatively, as a restriction to urinary outflow that, when left untreated, will cause progressive renal deterioration. Currently, management is mostly based on the latter definition, but still remains controversial. Relevant work published before 2002 is considered because of a lack of recent literature.

RECENT FINDINGS

Almost all reports comparing the primary conservative treatment of suspected obstruction versus early surgical intervention show comparable results, but there are different interpretations. The approach of 'watch and wait' for a unilateral hydronephrotic kidney with normal function is usually quite safe, with a very low risk of the permanent loss of renal function when accompanied by close monitoring, but it is certainly not without risk. At this time, the main underlying problems are that all currently applied diagnostic methods only detect effects secondary to obstruction, and the currently used definition of obstruction is based on a longitudinal observation period. The most relevant publication in the observation period was an in-depth report on a workshop in which the need for valid prospective markers for renal maldevelopment and 'significant' obstruction was expressed.

SUMMARY

The optimal management of infants with congenital hydronephrosis and suspected obstruction will remain controversial until new diagnostic methods are able to discriminate between 'harmful' and 'harmless' obstruction. Most experts currently advocate primary conservative management, with close follow-up and surgical intervention only if there are signs of reduced function of the obstructed kidney.

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.

Changing concepts in urological management of the congenital anomalies of kidney and urinary tract, CAKUT

Recent advancement in ultrasonographic evaluation has prompted early detection and diagnosis of congenital anomalies in the kidney and urinary tract (CAKUT) in the asymptomatic phase. Consequently, early surgical intervention has become possible in the asymptomatic phase for the purpose of controlling manifestations early, thereby avoiding renal functional deterioration. However, some lesions detected by ultrasonography have been shown to often resolve or disappear without intervention. Thus, it has become more important to identify and understand the natural history of CAKUT. For the precise evaluation of the results of surgical intervention, one must understand the maturational process of renal function during infancy. Without considering this process, we cannot differentiate the renal significance of the surgical management from the natural course of CAKUT. Recent advancement in the field of radioisotopic studies has also made a major contribution to the more precise assessment of renal function. Recent progress in the understanding of the pathophysiology and the natural history of CAKUT has helped rationalize its treatment and management. Improvement in the surgical techniques and tools, together with improvements in pediatric anesthesiology, have made an appreciably positive impact on the outcome. Herein, we present the emerging concepts in the urological management of CAKUT, specifically, multicystic dysplastic kidney, vesicoureteral reflux, congenital hydronephrosis, ectopic ureters and ureteroceles.

The results of 15 years of consistent strategy in treating antenatally suspected pelvi-ureteric junction obstruction

OBJECTIVE

To determine how to select patients for surgery among those with antenatally detected pelvi-ureteric junction (PUJ) obstruction.

PATIENTS AND METHODS

The study comprised 100 consecutive children with antenatally detected suspected unilateral PUJ obstruction and a normal contralateral kidney. The correct diagnosis was made using postnatal ultrasonography, intravenous urography and renal scintigraphy, the last also being used for the follow-up.

RESULTS

Four patients had poor function in the hydronephrotic kidney, treated in three by nephrectomy; 61 had normal function in the hydronephrotic kidney, with 49 followed for 1-10 years with no change in kidney function and no symptoms. Twelve patients in this group had later surgery (at 0.7-8 years old) because of pyelonephritis (four), pain and/or renal functional impairment (eight, three of whom had normal function afterward). Thirty-five patients had moderately impaired function of the hydronephrotic kidney; 29 had primary surgery at a median age of 4 months. The median hydronephrotic renal function increased from 32% before to 42% after surgery, with 15 kidneys having normal function. In one other patient the kidney was lost before surgery. Five other patients were initially treated conservatively and the hydronephrotic renal function increased from 32% to 35% at the 1-year follow-up, significantly less than in the surgical group. The overall operative complication rate was 4%.

CONCLUSIONS

With our management programme more than half the patients can avoid surgery in childhood. Although the follow-up was intense there was moderate and irreversible functional kidney deterioration in 5%. In contrast, after successful reconstructive surgery, only a few follow-up procedures causing possible discomfort to the child are needed in most. The risk of surgical complications cannot be neglected. The present results are useful for advising parents deciding whether their antenatally detected hydronephrotic child should undergo surgery or not.

Pyeloplasty in infancy

OBJECTIVE

The advent of routine maternal ultrasound has increased the number of neonates diagnosed to have ureteropelvic junction obstruction. Though the debate concerning its ideal management continues, recent years have witnessed reports on pyeloplasty in infancy. This study presents the feasibility and outcome of pyeloplasty in neonates and infants from a single centre.

METHODS

The authors examined the records of 40 neonates and infants (46 renal units) who underwent pyeloplasty for ureteropelvic junction obstruction since 1988. Patient characteristics, clinical presentation, investigations, associated anomalies, age at surgery, operative technique and outcome were evaluated.

RESULT

The mean and median age at surgery was 3.5 and 2.5 months respectively, and mean postoperative hospital stay six days. Associated anomalies were found in 27% of infants and in some they influenced the outcome. In 72%, no stent or nephrostomy was used. However, all had a closed perinephric drain. There was no mortality in this series. Complications (8.7%) comprised anastomotic leak in three and anastomotic stricture in one unit. In 35 of 38 renal units, improved drainage and recovery of differential function was confirmed on postoperative renogram.

CONCLUSION

Where indicated, pyeloplasty in the neonate and infant will be readily adopted by specialists for the select few it would benefit. It is hoped that all those involved in the care of these infants will take cognisance of this fact to ensure early optimal management of ureteropelvic junction obstruction.

Analysis of trends on serial ultrasound for high grade neonatal hydronephrosis

PURPOSE

We sought to validate the role of serial ultrasound studies for detecting and excluding obstruction in high grade neonatal hydronephrosis.

MATERIALS AND METHODS

Between January 1996 and December 1998 all patients with prenatally diagnosed hydronephrosis underwent a protocol of antibiotic prophylaxis, ultrasound and voiding cystourethrography. All reflux-free patients underwent diuretic renography. Patients with high grade isolated unilateral hydronephrosis were included in the study. They were followed with 3 serial ultrasound examinations every 3 months in year 1 of life, biannually in year 2 and yearly thereafter. The trends in the changes in these studies were studied.

RESULTS

Of the 153 patients 45 (29%) met study inclusion criteria. During a mean followup of 38 months (range 23 to 52) 16 patients (36%) who showed a trend of progressive hydronephrosis underwent pyeloplasty. The remaining 29 patients showed a trend of improvement in hydronephrosis. The drainage pattern on initial diuretic renography had only 63% sensitivity and 59% specificity for diagnosing obstruction. The same was true for the decrease in differential function of below 40% with 56% sensitivity and 66% specificity. Logistic regression analysis revealed that neither the initial grade of hydronephrosis on prenatal ultrasound nor the drainage-functional pattern on initial diuretic renography was a predictor of the subsequent need for pyeloplasty. All 16 patients who underwent pyeloplasty had improved or stabilized hydronephrosis after pyeloplasty.

CONCLUSIONS

A trend of progressive hydronephrosis on 2 consecutive serial renal ultrasound examinations serves as an early diagnostic sign of obstruction. Initial grade of hydronephrosis on initial ultrasound as well initial functional-drainage patterns on diuretic renography are not predictors of obstruction. Serial ultrasound is noninvasive and could replace serial invasive renal scans. Diuretic renal scans still have a role, especially as a baseline study to guide the frequency of serial ultrasound examinations.

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.

Successful early pyeloplasty in infants

BACKGROUND

Early pyeloplasty for the treatment of congenital ureteropelvic junction obstruction to maximize nephron salvage is justified only if potential hazards of operating on small infants are avoided.

METHODS

The records were analyzed of all infants who underwent pyeloplasty over a 5-year period. Open pyeloplasty was performed if collecting systems had deteriorated or were demonstrated to be obstructed; it was also performed for severe cases of hydronephrosis. Outcome of surgery in the younger infant (patients <2 months of age) was compared with the older infant group (patients >2 months of age). Preoperative evaluation in case of mild or moderate hydronephrosis was directed toward ruling out a non-obstructed collection system and included voiding cystourethrography, and serial ultrasonography and/or dual isotope diuretic renography. Postoperative assessment consisted of serial ultrasonography and/or nuclear imaging to confirm decompression and relief of obstruction.

RESULTS

A total of 24 pyeloplasties were performed on 22 patients in the younger infant group (two bilateral) and 30 were performed on 27 infants in the older infant group (three bilateral). The only significant differences between the groups were as follows: patients in the younger infant group were likely to present in utero (75%, p = 2.69), whereas those in the older infant group were more likely to present with a urinary tract infection (48%, p = 4.12). During follow-up examination, 23 renal units in the younger infant group and 24 in the older infant group were judged to be stable or improved. Four kidneys were not salvaged after pyeloplasty, one in the younger infant group and three in the older infant group.

CONCLUSIONS

Good results of pyeloplasties performed in the infants in this series support early correction of ureteropelvic junction obstruction in infants.

[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.

Clinical impact of differential renal function to indicate and assess pyeloplasty and the significance of coexisting vesicoureteral reflux

PURPOSE

In patients with ureteropelvic junction obstruction (JPJO) who are conservatively treated, 5% to 10% of them show a deterioration of renal function without recovery after delayed pyeloplasty. Should surgery be indicated based on observed deterioration of differential renal function (DRF)? Can we expect improvement of the DRF after pyeloplasty? What other influencing parameters may affect DRF?

MATERIALS AND METHODS

In this study, the authors examined 85 ureterorenal junctions that had undergone the Anderson-Hynes technique for surgical correction of UPJO. Based on the values obtained from the preoperative DRF (Tc-99m mercaptoacetyltriglycine), the cases were separated into three categories: group I had poor DRF (less than 11% of total renal function [TRF]), group II had moderate DRF (11% to 33% of TRF), and group III had adequate DRF (more than 33% of TRF). Twelve months after surgery, renal function was reassessed. The results were correlated with age at surgery, symptoms, coexisting vesicoureteral reflux, and drainage.

RESULTS

Seven ureterorenal junctions (8%) comprised group I, 15 (18%) comprised group II, and 63 (74%) comprised group III. After UPJO repair, 13% showed marked improvement in DRF, 86% remained stable, and 1% exhibited diminished function. In 50% of the renal cases with preoperative DRF less than 33%, postoperative improvement was seen. In follow-up renal scans, 30 cases (35%) revealed nonobstructive drainage, whereas the remaining 53 junctions (62%) showed moderate delayed drainage. Both the moderate delayed group (57%) and the nonobstructive group (50%) showed similar DRF improvement. Sixty-six percent of the patients with impaired DRF improved after pyeloplasty performed within the first 3 months of life, compared with 42.8% of patients in whom surgery was performed after 5 years of age. Vesicoureteral reflux was evident in 27.2% of the patients with preoperative impaired DRF compared with 11% with normal DRF. Forty-five percent of the patients with impaired DRF and no improvement after surgery had coexisting vesicoureteral reflux, compared with 9% of those with postoperative improvement.

CONCLUSIONS

Sustained renal impairment after pyeloplasty is likely as a result of preexisting renal dysplasia with vesicoureteral reflux. Moderate delayed drainage after surgery does not affect DRF. Surgery for UPJO should be indicated independent of a DRF follow-up (except very low DRF) or the age at the time of diagnosis.

The use of renal scintigraphy in assessing the potential for recovery in the obstructed renal tract in children

OBJECTIVE

To assess the value of renal scintigraphy with 99mTc-dimercaptosuccinic acid (DMSA) in predicting functional recovery after the surgical relief of obstructed kidneys in children. Patients and methods Forty-three children underwent surgery to relieve upper urinary tract obstruction; 37 had pelvi-ureteric junction obstruction and six had vesico-ureteric junction obstruction. The indication for surgery was a combination of an obstructed renogram with symptoms of either pain or pyelonephritis. Most children (41) had < 40% function on the affected side before surgery, with just two having hyperfunction (> 55%). In all patients intravenous urography before surgery showed hydronephrosis, and a micturating cystogram was used to exclude coexisting reflux in the presence of an associated megaureter. Diuretic renography (using 99mTc-mercaptoacetyl triglycine or 123I-hippuran) and DMSA scintigraphy were both carried out before surgery and the renography repeated 6 months afterward.

RESULTS

The renographic drainage curves improved from obstructed to unobstructed or 'dilated unobstructed' on all postoperative studies. Regression analysis showed that preoperative DMSA scan was an excellent predictor of outcome (P < 0.001) whilst the preoperative renogram was a relatively poor predictor of the functional result. In four patients where the initial renographic function was < 10%, DMSA scintigraphy predicted correctly the capacity for recovery in three and the inability to improve in the fourth. Conclusion Before surgery, DMSA scintigraphy in children with upper urinary tract obstruction is a more useful estimate of probable long-term renal function than value from diuresis renography. If there is doubt about the desirability of reconstructive surgery, a DMSA scan may eliminate the need for more invasive methods of estimating recovery, e.g. a period of nephrostomy drainage.

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.