Pathophysiology and treatment of ureteropelvic junction obstruction

Laparoscopic pyeloplasty for newborns with severe hydronephrosis

Aim

We aimed to investigate the short-term efficacy and safety of laparoscopic pyeloplasty for treating newborns with severe hydronephrosis due to ureteropelvic junction obstruction (UPJO).

Methods

A retrospective analysis was performed on 16 newborn patients with severe neonatal hydronephrosis who underwent laparoscopic pyeloplasty at our hospital from January 2021 to November 2022. All patients were regularly followed up. Laparoscopic pyeloplasty with double J stent placement was performed after the presence of severe hydronephrosis was confirmed.

Results

Among the 16 pediatric patients (13 males, 3 females), the left side was affected in 13 cases and the right side in 3. The average age at surgery was 9.50 (8.50-12.00) days, with an average weight of 3.30 ± 0.95 kg. Laparoscopic pyeloplasty was performed in all cases without the need for open conversion. The mean surgery duration was 292.06 ± 73.60 min, with minimal blood loss (2.50, 2.00-5.00 ml). Postoperative hospital stays averaged 13.44 ± 4.70 days. No anastomotic leakage occurred, and follow-ups at 1, 3, 6, and 12 months showed no stent displacement, except for one case where the stent was removed at 1 month, and the others at 3 months. There were no cases of worsened hydronephrosis, except for one with renal atrophy at the 6-month follow-up. Changes in renal pelvis anteroposterior diameter exhibited a time effect (F = 49.281, P < 0.001), with significant differences at 1, 3, 6, and 12 months postoperatively compared to preoperative values (P < 0.05). Notably, differences were observed between 6 and 3 months, as well as between 12 and 3 months postoperatively (P < 0.05). Similarly, renal parenchymal thickness changes showed a time effect Pediatric urology, Guangdong Women and Children Hospital, Guangzhou, China (F = 49.281, P < 0.001), with significant differences at 1, 3, 6, and 12 months postoperatively compared to preoperative values (P < 0.05). Significant differences were also noted between 6 and 1 month, as well as between 12 and 1 month postoperatively (P < 0.05). There was one case of urinary tract infection after surgery, and no case of recurrence was observed.

Conclusion

Severe neonatal hydronephrosis must be treated promptly. Laparoscopic pyeloplasty is a safe and feasible treatment with minimal complications for newborn patients with severe hydronephrosis due to UPJO.

Pelviureteric junction obstruction in adults: A systematic review of the literature

Background

Pelviureteric junction obstruction (PUJO) is a common urological disorder that can present at any stage of life. The underlying etiology in children has been well studied; however, a gap exists in the literature for the adult population. Herein, we performed a systematic review of the literature to evaluate the current evidence on the underlying etiologies of adult patients presenting with PUJO.

Materials and methods

Four electronic databases were searched for relevant studies assessing the underlying etiologies of pelviureteric junction obstruction in adults. Studies were assessed for eligibility based on predefined inclusion and exclusion criteria, and a critical appraisal of methodological quality and risk of bias was performed. Finally, qualitative and quantitative data analyses were performed.

Results

Twelve studies comprising a total of 513 patients with radiologically confirmed PUJO met the inclusion criteria and were included in our analysis. The most common finding was crossing vessels, which were observed in 50.5% of patients, followed by intrinsic ureteral stenosis (27.1%), adhesions (15.3%), and high insertion of the ureter (10.1%).

Conclusions

The underlying etiologies of PUJO in adults remain unclear. This study indicated that obstruction secondary to crossing vessels is the most common cause of obstruction in adults and occurs more frequently than in the pediatric population.

Rare perinephric myxoid pseudotumor of fat causing ureteropelvic junction obstruction: a case report

Ureteropelvic junction obstruction (UPJO) is a congenital or acquired functionally significant impairment of urinary transport from the renal pelvis to the ureter. Congenital UPJO typically results from intrinsic disease such as the presence of an aperistaltic segment of the ureter, aberrant vessels or kidney abnormalities. Rare conditions can sometimes mimic an UPJO. We present a case of an 86-year-old woman with a UPJO diagnosed on CT. The patient was counseled on treatment options and elected to undergo a left uretherorenoscopy (URS) plus left laparoscopic pyeloplasty. The definitive histopathologic diagnosis was perinephric myxoid pseudotumor of fat, an extremely rare neoplasm, mass-forming. To the best of our knowledge, this is the first known case of a pseudotumor of fat causing UPJO. 6-month follow-up showed neither recurrence nor residual UPJO. We describe a rare presentation of extrinsic perinephric myxoid pseudotumor of fat causing UPJ obstruction. In elderly patients with no history of malignancy, UPJ obstruction can occur because of atypical masses.

Imaging of congenital genitourinary anomalies

Congenital genitourinary anomalies are among the most frequent types of birth defects in neonates. Some anomalies can be a significant cause of morbidity in infancy, while others remain asymptomatic even until adulthood and can be at times the only manifestation of a complex systemic disease. The spectrum of these anomalies results from the developmental insults that can occur at various embryologic stages, and an understanding of the formation of the genitourinary system is helpful in the evaluation and treatment of a child with a congenital genitourinary anomaly. Imaging plays an essential role in the diagnosis of congenital genitourinary anomalies and treatment planning. In this article, we highlight the embryologic and characteristic imaging features of various congenital genitourinary anomalies, demonstrate the utility of different imaging modalities in management, and review specific imaging modalities and protocols for image optimization.

Outcome analysis of early surgery and conservative treatment in neonates and infants with severe hydronephrosis

Objective

The treatment strategy and timing of ureteropelvic junction obstruction (UPJO) in infants remain controversial. This study aimed to compare the effect of early surgical treatment (EST) and conservative treatment (CT) on neonates and infants with UPJO and their recovery of renal function and morphology.

Methods

Eighty neonates and infants with severe hydronephrosis were enrolled in this study. They received early pyeloureteroplasty or CT. Diethylenetriamine pentaacetate was used to assess renal function.

Results

There were no significant differences in renal function or renal indices at baseline between the two groups. At 3 and 6 months of follow-up, the anteroposterior diameter of the renal pelvis and the Society of Fetal Urology grade in the EST surgery group were significantly lower compared with those at baseline. The thickness of the renal cortex was greater in the EST group than in the CT group at 3 and 6 months of follow-up. After follow-up for 6 months, renal function in the EST group was significantly better than that in the CT group.

Conclusion

EST accelerates the recovery of renal morphological and functional indices in neonates and infants with severe hydronephrosis.

Concomitant management of renal calculi and recurrent ureteropelvic junction obstruction with percutaneous nephrolithotomy and antegrade balloon dilation

Objective

This study aimed to present our experience of concomitant management of renal calculi and recurrent ureteropelvic junction obstruction (UPJO) with percutaneous nephrolithotomy (PCNL) and antegrade balloon dilation.

Methods

We retrospectively reviewed 31 patients who underwent PCNL and antegrade balloon dilation for treatment of renal calculi and recurrent UPJO. The inclusion criterion was the presence of UPJO after failed pyeloplasty with ipsilateral renal calculi. Success was defined as achievement of both symptomatic and radiographic resolution of any stones and obstruction.

Results

All operations were successful without grade III or higher postoperative complications. A stone-free status was observed in all patients and the overall success rate of the procedure was 87.1% (27/31). The success rate of the procedure was significantly higher in patients with mild or moderate preoperative hydronephrosis (96%) than in those with high-grade preoperative hydronephrosis (50%). Moreover, the success rate of the procedure was lower in patients with poor preoperative renal function (0%) than in those with good or moderate renal function (93.1%).

Conclusion

Combined PCNL and antegrade balloon dilation management represents a safe and effective approach for patients with renal calculi and recurrent UPJO after failed pyeloplasty.

Congenital Anomalies of the Upper Urinary Tract: A Comprehensive Review

The upper urinary tract is the most common human system affected by congenital anomalies. Congenital anomalies of the kidneys and ureters comprise a wide spectrum of disorders ranging from simple variants with no clinical significance to complex anomalies that may lead to severe complications and end-stage renal disease. They may be classified as anomalies of renal form, which are subclassified as structural anomalies (eg, persistent fetal lobulation, hypertrophied column of Bertin, and dromedary hump) and fusion anomalies (eg, horseshoe kidney and pancake kidney); anomalies of renal position (eg, renal malrotation, simple renal ectopia, and crossed renal ectopia) and renal number (eg, renal agenesis and supernumerary kidney); and abnormalities in development of the urinary collecting system (eg, pyelocaliceal diverticulum, megacalycosis, ureteropelvic junction obstruction, duplex collecting system, megaureter, ectopic ureter, and ureterocele). US is usually the first imaging modality used because of its low cost, wide availability, and absence of ionizing radiation. Intravenous urography and voiding cystourethrography are also useful, mainly for characterization of the collecting system and vesicoureteral reflux. However, intravenous urography has been replaced by CT urography and MR urography. These imaging methods not only allow direct visualization of the collecting system but also demonstrate the function of the kidneys, the vascular anatomy, adjacent structures, and complications. Comprehension of congenital anomalies of the upper urinary tract is crucial for an accurate diagnosis and correct management. The authors discuss the spectrum of these anomalies, with emphasis on embryologic development, imaging findings, clinical manifestations, and complications. Online supplemental material is available for this article. ^©RSNA, 2021.

[A retrospective comparison of robotic assisted and conventional laparoscopic pyeloplasty in two centres]

Ziel

Wir verglichen in unserer retrospektiven Multicenterstudie die Ergebnisse der konventionell laparoskopischen Nierenbeckenplastik (L-NBP) mit denen der roboterassistierten Nierenbeckenplastik (R-NBP) nach Einführung des da Vinci X-Systems.

Methoden

Insgesamt wurden im definierten Zeitraum von Mai 2015 bis September 2019 76 Nierenbeckenplastiken an zwei unterschiedlichen Universitätskliniken durchgeführt. Für die Datenanalyse wurden 63 Patienten berücksichtigt, welche entweder eine L‑NBP (n = 27) oder eine R‑NBP (n = 36) nach Anderson und Hynse erhielten.

Ergebnisse

Das mediane Follow-up lag bei 22,5 (L-NBP) bzw. 12,7 (R-NBP) Monaten. Die statistische Analyse der Patientengruppen ergab bzgl. Alter, BMI, Geschlecht und betroffener Seite keinen statistischen Unterschied. Die Operationszeit war in der Gruppe der R‑NBP nicht statistisch signifikant kürzer (180 ± 72 vs. 159 ± 54 min, p = 0,194). Bezüglich postoperativer Major- bzw. Minor-Komplikationen nach Clavien-Dindo, Krankenhausaufenthaltsdauern (7,48 ± 2,86 vs. 6,33 ± 2,04 Tage) und Erfolgsrate ergab sich ebenso kein statistisch signifikanter Unterschied.

Schlussfolgerung

Unsere Daten zeigen keinen signifikanten Unterschied der beiden Gruppen bezogen auf die peri- und postoperativen Ergebnisse. Es konnte gezeigt werden, dass für den Patienten auch unmittelbar nach Implementierung eines robotischen Systems kein Nachteil entsteht.

Symptomatology and Clinic of Hydronephrosis Associated With Uretero Pelvic Junction Anomalies

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

Surgical management of pyelo-ureteral junction syndrome in a resource-limited setting: case of Zinder National Hospital, Niger

Background

Pyelo-ureteral junction syndrome (PUJS) is a frequent congenital malformation. We report the surgical management of PUJS by pyeloplasty according to Anderson-Hyne-Kuss’s procedure at the Zinder National Hospital..

Methods

This was a retrospective study from January 2013 to December 2016 (4 years), including patients who have undergone surgery for PUJS.

Results

Twelve (12) cases of PUJS had a surgery among which 66.7% were men with an average age of 32.5 ± 7.6 years. The clinical symptomatology was lumbar pain or renal colic in 92.3% of cases. This pain had evolved for more than 2 years for 58.3% of the cases. Ultrasound coupled with intravenous urography or CT-scan was performed to confirm the diagnosis of PUJS in 58.3 and 41.7% of cases. The average serum creatinine level at admission was 181.25 ± 67.3 μmol/L [Lab reference range: 53–97 μmol/L]. The Anderson-Hynes non dismembered pyeloplasty is used for all the patients. The release of a crossing lower pole vessel was performed in 25%, pyelolithotomy in 16.7%. The average surgery time was 118.3 ± 20.7 min. The average hospital length of stay was 10.8 ± 3 days. Immediate postoperative complications were recorded in 33.3% (n = 4). Postoperative outcomes were considered good by disappearance of clinical, biological and radiological signs.

Conclusion

The Anderson-Hynes non dismembered pyeloplasty gives good results and provides a successful alternative in an environment where laparoscopy and robotic surgery are not developed.

The next era of renal radionuclide imaging: novel PET radiotracers

Although single-photon-emitting radiotracers have long been the standard for renal functional molecular imaging, recent years have seen the development of positron emission tomography (PET) agents for this application. We provide an overview of renal radionuclide PET radiotracers, in particular focusing on novel 18F-labelled and 68Ga-labelled agents. Several reported PET imaging probes allow assessment of glomerular filtration rate, such as [68Ga]ethylenediaminetetraacetic acid ([68Ga]EDTA), [68Ga]IRDye800-tilmanocept and 2-deoxy-2-[18F]fluorosorbitol ([18F]FDS)). The diagnostic performance of [68Ga]EDTA has already been demonstrated in a clinical trial. [68Ga]IRDye800-tilmanocept shows receptor-mediated binding to glomerular mesangial cells, which in turn may allow the monitoring of progression of diabetic nephropathy. [18F]FDS shows excellent kidney extraction and excretion in rats and, as has been shown in the first study in humans. Further, due to its simple one-step radiosynthesis via the most frequently used PET radiotracer 2-deoxy-2-[18F]fluoro-D-glucose, [18F]FDS could be available at nearly every PET centre. A new PET radiotracer has also been introduced for the effective assessment of plasma flow in the kidneys: Re(CO)3-N-([18F]fluoroethyl)iminodiacetic acid (Re(CO)3([18F]FEDA)). This compound demonstrates similar pharmacokinetic properties to its 99mTc-labelled analogue [99mTc](CO)3(FEDA). Thus, if there is a shortage of molybdenum-99, Re(CO)3([18F]FEDA would allow direct comparison with previous studies with 99mTc. The PET radiotracers for renal imaging reviewed here allow thorough evaluation of kidney function, with the tremendous advantage of precise anatomical coregistration with simultaneously acquired CT images and rapid three-dimensional imaging capability.

Novel Functional Renal PET Imaging With 18F-FDS in Human Subjects

The novel PET probe 2-deoxy-2-F-fluoro-D-sorbitol (F-FDS) has demonstrated favorable renal kinetics in animals. We aimed to elucidate its imaging properties in 2 human volunteers. F-FDS was produced by a simple 1-step reduction from F-FDG. On dynamic renal PET, the cortex was delineated and activity gradually transited in the parenchyma, followed by radiotracer excretion. No adverse effects were reported. Given the higher spatiotemporal resolution of PET relative to conventional scintigraphy, F-FDS PET offers a more thorough evaluation of human renal kinetics. Due to its simple production from F-FDG, F-FDS is virtually available at any PET facility with radiochemistry infrastructure.

Robot-assisted laparoscopic pyeloplasty versus laparoscopic pyeloplasty for pelvi-ureteric junction obstruction in the paediatric population: a systematic review and meta-analysis

Background

Owing to the improved vision and instrument manipulation in robot-assisted procedures, we sought to evaluate the comparative outcomes of robot-assisted laparoscopic pyeloplasty (RALP) and laparoscopic pyeloplasty (LP) in a paediatric patients with pelvi-ureteric junction obstruction (PUJO).

Methods

We conducted a systemic literature search of online sources, including PubMed, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials, and respective bibliographic reference lists. Success rate, operative time, hospital length of stay, postoperative complication rate and re-intervention rate were our primary outcomes. Combined overall effect sizes were calculated using fixed-effect or random-effects models.

Results

We identified 14 observational studies reporting a total of 2254 paediatric patients with PUJO, who underwent LP (n = 1021) or RALP (n = 1233). Our analysis demonstrated that RALP was associated with a significantly higher success rate [odds ratio (OR) 2.51; 95% confidence interval (CI) 1.08-5.83, p = 0.03] and shorter length of hospital stay [mean difference (MD) -1.49; 95% CI -2.22 to -077; p < 0.0001] compared with LP. Moreover, nonsignificant reductions in postoperative complications (OR 0.61; 95% CI 0.36-1.02; p = 0.06) and re-intervention (OR 0.43; 95% CI 0.15-1.21; p = 0.11) were found in favour of RALP. There was no difference in procedure time between the two approaches (MD -0.15; 95% CI -30.22 to 29.93, p = 0.99).

Conclusions

Our meta-analysis of observational studies demonstrated that RALP is safe and may have higher success rate compared with the more traditional laparoscopic approach in a paediatric population. Moreover, it may be associated with lower postoperative complications and re-intervention rates. Evidence from randomized trials is required.

Pilot study on renal magnetic resonance diffusion tensor imaging: are quantitative diffusion tensor imaging values useful in the evaluation of children with ureteropelvic junction obstruction?

BACKGROUND

Ureteropelvic junction (UPJ) obstruction is a common cause of renal injury in children. Indications for surgery are still controversial. Currently, there is no threshold to differentiate patients with suspected UPJ obstruction requiring surgery from the ones that do not, or to predict renal outcome after surgery. Several studies have demonstrated that diffusion tensor imaging (DTI) results may correlate with microstructural changes in the kidneys.

OBJECTIVE

To evaluate the feasibility of using DTI to identify UPJ obstruction kidneys.

MATERIALS AND METHODS

We analyzed functional MR urography (fMRU) with renal DTI (b=0 and b=400, 20 directions, 1.5 Tesla, no respiratory triggering) in 26 kidneys of 19 children (mean age: 6.15 years) by comparing 13 kidneys with UPJ obstruction configuration that underwent pyeloplasty following the fMRU, and 13 anatomically normal age- and gender-matched kidneys. DTI tractography was reconstructed using a fractional anisotropy threshold of 0.10 and an angle threshold of 55°. User-defined regions of interest (ROIs) of the renal parenchyma (excluding collecting system) were drawn to quantify DTI parameters: fractional anisotropy, apparent diffusion coefficient (ADC), track length and track volume. The failure rate was evaluated.

RESULTS

All DTI parameters changed with age; fractional anisotropy decreased (P<0.032). Track volume and track length increased (P<0.05). ADC increased with age in normal kidneys (P<0.001) but not in UPJ obstruction kidneys (P=0.11). After controlling for age, the fractional anisotropy (UPJ obstruction mean: 0.18, normal kidney mean: 0.21; P=0.001) and track length (UPJ obstruction mean: 11.9 mm, normal kidney mean: 15.4 mm; P<0.001) were lower in UPJ obstruction vs. normal kidneys. There was a trend toward a higher ADC in UPJ obstruction kidneys vs. normal kidneys (P=0.062). The failure rate in UPJ obstruction kidneys due to technical limitations of DTI was 13/26 (50%).

CONCLUSION

We demonstrated that fractional anisotropy is lower in UPJ obstruction than in normal kidneys. It is necessary to improve this technique to increase the success rate and to perform more studies to evaluate if a decrease in fractional anisotropy can differentiate UPJ obstruction kidneys from hydronephrotic kidneys without UPJ obstruction.

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.

Laser Endopyelotomy in the Management of Pelviureteric Junction Obstruction in Adults: A Systematic Review of the Literature

Laser endopyelotomy (LEP) is considered as an option for the treatment of pelviureteric junction obstruction in adults. A comprehensive systematic search of the published literature was performed to assess the success rate and perioperative complications of LEP in the treatment of primary and secondary pelviureteric junction obstruction and to identify the factors that may have an impact on the success of LEP. The evidence available has significant limitations in terms of the heterogeneous study design and the definitions of outcomes. The average overall success rate of the pooled data was 75% with a mean follow-up of 29 months. Complications were predominately minor with an average rate of 12.5%.

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.

Comparison of Retrograde Balloon Dilatation and Laparoscopic Pyeloplasty for Treatment of Ureteropelvic Junction Obstruction: Results of a 2-Year Follow-Up

Objective

To evaluate the efficacy of laparoscopic pyeloplasty relative to retrograde balloon dilatation for the treatment of ureteropelvic junction obstruction (UPJO).

Methods

This retrospective study enrolled UPJO patients with stricture length < 2 cm who had been treated with laparoscopic pyeloplasty (LP; 44 cases) or balloon dilatation (BD; 38 cases) from Jan 2010 to Jan 2012, according to patients’ preference after consultation. Demographics and clinical parameters were collected. Patients were followed-up at 3, 6, 12, and 24 months. Ultrasonography, intravenous urography, and diuretic renography were applied to evaluate the remission of hydronephrosis.

Results

Both groups were comparable with respect to age, UPJO location, gender, and other baseline parameters. Compared to the LP group, patients receiving BD experienced significantly shorter operative time, analgesia time, hospital stay, and urethral catheter indwelling time, and less cost (P<0.001). Three and 6 months after their respective procedures, the success rates of the LP (97.7%, both) and BD (94.7% and 86.8%) groups were similar, and at 12 and 24 months the long-term success rate of LP (95.5%, both) was better than that of BD (78.9% and 71.0%).

Conclusions

LP showed better long-term success rate than did BD in the management of UPJO with length of stricture < 2 cm. Considering that BD is more minimally invasive, simpler and easier to perform, and costs less, we recommend it for some selective UPJO patients as the first-line therapy.

Congenital Anomalies of the Kidney and the Urinary Tract (CAKUT)

This article reviews the majority of Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) with emphasis in Pediatric Pathology describing and illustrating lesions as varied as ureteral duplications, ureteropelvic junction obstruction, horseshoe kidney, posterior urethral valve and prune belly syndrome, obstructive renal dysplasia, nonmotile ciliopathies and several syndromes associated with renal malformations (Meckel-Joubert, short rib, Bardet-Biedl, asplenia/polysplenia, hereditary renal adysplasia, Zellweger, trisomies, VACTER-L, Potter, caudal dysplasia, and sirenomelia), as well as ADPK, and ARPK. The purpose of this review is not only to describe the congenital renal anomalies, but also to analyze the more recent therapeutic interventions that may modify the natural history of some of these severe conditions.

A curable and probably often-overlooked cause of cyclic vomiting syndrome

Cyclic vomiting syndrome is a disorder of many causes. The major challenge is to label the disorder as idiopathic or primary only when all possible etiologies, particularly those that can be specifically treated, have been ruled out. In retrospect, our patient had subtle prenatal and early postnatal radiological findings supportive of a urological cause for his symptoms, the importance of which was initially missed. It would probably be wise to include an abdominal ultrasound examination (looking for hydronephrosis) in the "must-do" battery of tests for the investigation of all cases of recurrent cyclic vomiting without apparent cause. Otherwise, it seems likely that many cases of ureteropelvic junction obstruction will be missed, cases in which surgical intervention can be curative.

Left nutcracker syndrome and right ureteropelvic junction obstruction

We report a rare case of left nutcracker syndrome and right ureteropelvic junction obstruction in a young woman who suffered flank pain and hematuria. The diagnosis was confirmed with the help of Doppler ultrasonography, retrograde pyelography, magnetic resonance angiography, and magnetic resonance urography. A surgery that involves left renal vein decompression and dismembered Anderson-Hynes pelvioplasty was performed. The patient was followed up for 23 months, and her symptoms were relieved.

Prone versus supine lasix renal scan to assess surgical success after laparoscopic and robot-assisted pyeloplasty

PURPOSE

Success after laparoscopic pyeloplasty (LP) for ureteropelvic junction obstruction is determined based on renal scan (RS) results and patient symptoms ± ultrasonography. The upright or prone position during RS may facilitate drainage. This study reports on outcomes after LP and robot-assisted pyeloplasty (RALP) and determines if patient position (supine vs prone) alters the results of the postoperative RS and surgical "success."

PATIENTS AND METHODS

A retrospective review of LP and RALP performed by one surgeon between 2005 and 2012 was performed. Follow-up consisted of RS ± ultrasonography. The paired t test was used to assess for a significant difference between mean T1/2 for supine vs prone scans in each patient. Linear regression was used to determine if preoperative split renal function on the affected side or degree of preoperative hydronephrosis predicted difference in supine vs prone T1/2.

RESULTS

There were 11 LP and 81 RALP performed; 84 had follow-up data. There were four (4.3%) failures. Thirty-eight patients had sufficient supine and prone RS for analysis. The difference in T1/2 between supine and prone RS was significant (mean difference 10.18 ± 27.28 min, P = 0.03). Strict success increased to 65.8% from 44.7% and combined strict plus technical success increased to 78.9% from 63.1% on prone vs supine RS. Split function and degree of hydronephrosis were not predictors of difference in RS results.

CONCLUSIONS

LP and RALP have good technical results. Prone position for RS may facilitate drainage and may be a more accurate representation of postoperative outcome after pyeloplasty, particularly in equivocal cases.

Postnatal imaging of neonates with prenatally diagnosed genitourinary abnormalities: a practical approach

The advent of prenatal US and, more recently, fetal MRI has changed our pattern of referrals. In the current clinical algorithms, most neonates evaluated for genitourinary abnormalities are asymptomatic. These infants are referred for multidisciplinary consultation, imaging and surveillance. Evaluation of these children commences following pertinent review of available prenatal studies; this is appropriate, as in certain instances prenatally gathered information of potential prognostic significance can be inferred or can obviate the need for multiple examinations. US remains the first-line imaging modality for diagnosing urinary abnormalities in neonates and young infants, although it offers primarily morphological assessment. However, US coupled with MAG-3 scanning results in a powerful combination that provides anatomical and functional information. Recently, MRI and MR urography have been increasingly regarded as one-stop-shop examinations that can deliver both anatomical and functional information, and play an increasing role in the evaluation of ureteral ectopia and genital anomalies. Fluoroscopic examinations are reserved to exclude vesicoureteral reflux, to delineate urethral obstruction or to provide additional information to support a diagnosis. A practical approach to postnatal imaging of the neonate is discussed and the important genitourinary anomalies in this age group are presented and illustrated.

The role of routine post-natal abdominal ultrasound for newborns in a resource-poor setting: a longitudinal study

Background-

Neonatal abdominal ultrasound is usually performed in Nigeria to investigate neonatal symptoms rather than as a follow up to evaluate fetal abnormalities which were detected on prenatal ultrasound. The role of routine obstetric ultrasonography in the monitoring of pregnancy and identification of fetal malformations has partly contributed to lowering of fetal mortality rates. In Nigeria which has a high maternal and fetal mortality rate, many pregnant women do not have ante-natal care and not infrequently, women also deliver their babies at home and only bring the newborns to the clinics for immunization. Even when performed, most routine obstetric scans are not targeted towards the detection of fetal abnormalities.

The aim of the present study is to evaluate the benefit of routinely performing abdominal scans on newborns with a view to detecting possible abnormalities which may have been missed ante-natally.

Methods-

This was a longitudinal study of 202 consecutive, apparently normal newborns. Routine clinical examination and abdominal ultrasound scans were performed on the babies by their mother's bedside, before discharge. Neonates with abnormal initial scans had follow-up scans.

Results-

There were 108 males and 94 females. There were 12 (5.9%) abnormal scans seen in five male and seven female neonates. Eleven of the twelve abnormalities were in the kidneys, six on the left and five on the right. Three of the four major renal anomalies- absent kidney, ectopic/pelvic kidney and two cases of severe hydronephrosis were however on the left side. There was one suprarenal abnormality on the right suspected to be a possible infected adrenal haemorrage. Nine of the abnormal cases reported for follow- up and of these, two cases had persistent severe abnormalities.

Conclusions-

This study demonstrated a 5.9% incidence of genito urinary anomalies on routine neonatal abdominal ultrasound in this small population. Routine obstetric USS is very useful but inadequate availability of skilled personnel and cost implications create great challenges in poor resource settings like Nigeria. However, awareness should be created so that parents who can afford such investigations can make informed decisions.

Investigation of histopathologic changes in pelviureteral junction obstruction

OBJECTIVES

This study aimed to determine histopathologic changes in the pelviureteral junction in children with pelviureteral junction obstruction.

MATERIAL AND METHODS

Seventeen pelviureteral junction specimens obtained from children were divided into two groups: pelviureteral junction obstruction (n = 7) and control (n = 10). Wall thickness of the pelviureteral junction, tunica muscularis of the pelviureteral junction, uroepithelium thickness of the pelviureteral junction, and collagen thickness of the pelviureteral junction were evaluated in resected pelviureteral junctions in children with pelviureteral junction obstruction.

MAIN FINDINGS

The mean wall thickness of the pelviureteral junction, mean tunica muscularis of the pelviureteral junction, and uroepithelium thickness of the pelviureteral junction were not significantly higher than those in the control group. Collagen thickness values in the pelviureteral junction obstruction group were significantly higher than those in the control group.

CONCLUSIONS

Our data suggest that wall thickness (tunica muscularis and uroepithelium) was not significantly increased, but collagen thickness of the ureter was increased in the pelviureteral junctions of children with pelviureteral junction obstruction.

Outcome analysis of robotic pyeloplasty: a large single-centre experience

OBJECTIVE

To present our experience and outcomes of robot-assisted laparoscopic pyeloplasty (RALP) for pelvi-ureteric junction obstruction (PUJO).

PATIENTS AND METHODS

This was a prospective study of 85 consecutive patients who had RALP for PUJO at our institute from July 2006 to December 2008. The preoperative evaluation included intravenous urography (IVU) and diuretic renography. The type of pyeloplasty was decided based on the size of the pelves, presence of crossing vessel, level of ureteric insertion and the length of obstruction. All surgery was done through a transperitoneal approach using four or five ports. The follow-up comprised IVU and renal dynamic scintigraphy. Relevant data were collected and analysed for perioperative morbidity, complications and long-term functional outcomes.

RESULTS

In all, 86 RALPs were performed, including one bilateral, 41 right-sided and 43 left-sided cases. The mean operative time was 121 min, including an anastomosis time of 47 min. The mean estimated blood loss was 45 mL. The drain was removed within 48 h. The mean hospital stay was 2.5 days. Three patients had stents that migrated upwards, and prolonged drainage. The success rate was 97% (82/85) with a mean follow-up of 13.6 months.

CONCLUSIONS

RALP is highly effective for managing PUJO, with low morbidity, quick recovery and a durable success rate.

Postnatal evaluation of infants with an abnormal antenatal renal sonogram

PURPOSE OF REVIEW

Antenatally detected renal abnormalities are frequently encountered. Recommended postnatal evaluation of these infants has evolved to minimize invasive testing while maximizing detection of significant abnormalities.

RECENT FINDINGS

There is a low rate of detectable renal abnormalities in infants with a normal postnatal sonogram at 4-6 weeks of age. Routine prophylactic antibiotics are not indicated in infants with isolated antenatal hydronephrosis. Infants with a multicystic dysplastic kidney and a normal contralateral kidney on renal ultrasound do not require further evaluation. Parents of these children should be counseled on symptoms of urinary tract infections to allow prompt diagnosis.

SUMMARY

All infants with abnormalities on antenatal sonogram should undergo postnatal evaluation with a sonogram after birth and at 4-6 weeks of age. Further evaluation can be safely limited when the postnatal sonogram is normal at 6 weeks of age.