Undescended testis: A roundtable discussion based on clinical scenarios - Part 1

Undescended testis (UDT, cryptorchidism) is the most common congenital anomaly of the genital tract. Despite its high incidence, the management of UDT varies between specialties (urology, pediatric surgery, pediatric urology, pediatric endocrinology). Therefore, as the European Association of Urology - Young Academic Urologists Pediatric Urology Working Group, we requested experts around the world to express their own personal approaches against various case scenarios of UDT in order to explore their individual reasoning. We intended to broaden the perspectives of our colleagues who deal with the treatment of this frequent genital malformation.

[Possibilities and limitations of national guidelines based on the example of pediatric urology guidelines from the Pediatric Urology Working Group of the Austrian Society for Urology and Andrology (ÖGU)]

BACKGROUND

Medical guidelines are defined as practical orientation and decision-making aids; they are legally defined as noncommittal recommendations. International guidelines are written in very general terms, especially in the case of heterogeneous clinical pictures (e.g., vesicoureteral reflux).

OBJECTIVE

Could national guidelines based on international recommendations become authoritative as specific treatment recommendations for the various specialist groups?

MATERIALS AND METHODS

The value of international and national guidelines was assessed using the example case history of a child affected with vesicoureteral reflux.

RESULTS

Due to the various therapeutic possibilities according to various guidelines, the child received unfavorable, incongruent, delayed, and repeated unsuccessful attempts with different treatment regimes CONCLUSION: Due to the nonbinding nature of general guidelines, there is a risk of suboptimal therapy. National guidelines aimed at individualized treatment recommendations should aim for higher medical and legal status.

Being born small for gestational age (SGA) might be associated with a higher reoperation rate in proximal hypospadias

PURPOSE

Being born small for gestational age (SGA) is associated with a higher frequency and more severe forms of hypospadias as well as with potential developmental differences. This study aims to characterize operative outcomes in SGA boys compared to boys born with normal weight and length for gestational age (appropriate/large for gestational age, AGA/LGA).

METHODS

Demographic data, hypospadias characteristics, associated pathologies and operative outcomes of boys who underwent hypospadias repair at a single center (10/2012-10/2019) were evaluated. Boys were categorized into SGA and non-SGA, which were then compared using unpaired t-tests and chi square tests. To examine the effect of SGA on reoperative risk, a logistic regression model was applied integrating surgical technique, meatal localization and complex hypospadias (narrow glans/plate, curvature, micropenis, bilateral cryptorchidism).

RESULTS

SGA boys accounted for 13.7% (n = 80) of the total cohort (n = 584) and 33% of all proximal hypospadias (n = 99, SGA vs. non-SGA 41.3% vs. 13%, p < 0.001). After a mean follow-up of 18.6 months the reoperation rate for all hypospadias was 17.9% (n = 105). In distal hypospadias there was no difference in reoperation rate between SGA and AGA/LGA boys (p = 0.548, multivariate regression model). For each meatal localization in proximal hypospadias SGA was a significant, independent factor predicting higher reoperation rates (p = 0.019, OR 3.21) in a logistic regression model (Figure ROC).

DISCUSSION

Hypospadias surgery carries a substantial risk for unplanned reinterventions. Apart from meatal localization, there are only a few factors (urethral plate quality, glandular diameter, curvature) reported in literature to be associated with reoperative risk. Intrauterine growth retardation associated with SGA might lead to not only a higher probability of proximal hypospadias but also contribute to a higher risk for complications mediated by developmental differences. Whether these findings could help to tailor surgical strategies or adjuvant measures, as for example the application of preoperative hormonal stimulation remains to be determined in future studies. This study is limited by being a single-center series with limited follow-up resulting in some complications probably not yet detected - however, in the same extent in both groups.

CONCLUSION

Based on this study, 33% of all proximal hypospadias cases occur in boys born SGA. While the reoperation rate in boys with distal hypospadias was not influenced by SGA status, SGA proved to be an independent predictor of a higher risk of reoperation in those with proximal hypospadias. After validation of these findings in other centers, this could be integrated into counseling and risk-stratification.

Detection of bladder trabeculation by voiding cystourethrography and sonography: observations in boys with posterior urethral valves

Background

As trabeculated bladder wall is often referred to as a sign of chronically increased intravesical pressure, we investigated whether voiding cystourethrography (VCUG) or sonography reliably predicts bladder trabeculation on later urethrocystoscopy.

Methods

A total of 76 consecutive patients (2012–2017) with cystoscopically confirmed posterior urethral valves (PUV) and pre-endoscopy VCUG were included. Sonography data were available for 68 of these patients. Radiological findings were reassessed and compared with endoscopic findings using Fisher’s exact test and Spearman’s rank assessment.

Results

VCUG showed a sensitivity of 83.3% and a specificity of 30% in predicting trabeculation on a later urethrocystoscopy, with no significant difference in determining mild or severe forms (p=0.51). Sonography proved a sensitivity of 27.6% and a specificity of 70%, with no correlation between sonographic signs and trabeculation on cystoscopy (r=0.1311). In addition, vesicoureteral reflux had no significant influence as a possible pressure pop-off mechanism on the development of trabeculation in our group.

Conclusions

While VCUG predicts bladder trabeculation in children with PUV with limited reliability, sonography mostly fails to detect trabeculation. Therefore, such findings should only be used with utmost caution in relation to clinical decision-making.

Sedation Rate Reduction in Paediatric Renal Nuclear Medicine Examinations: Consequences of a Targeted Audit

Background: Nuclear medicine investigations are essential diagnostic tools in paediatric urology. Child-orientated examination techniques and the avoidance of sedation or anaesthesia vary in different institutions. We aimed at evaluating child friendly measures in our department to identify the potential for improvement. Based on these data, we changed the standards regarding the sedation policy and consequently re-evaluated sedation rates. Methods: Four-hundred thirty-five consecutive investigations were evaluated regarding the need for sedation, outcome and patient satisfaction at our department. After the revision of our department standards, we re-evaluated 159 examinations. Statistical analysis was performed with JUMBO (Java-supported Münsterian biometrical platform). Results: Eighty-six percent (60/70) would agree to perform an investigation under identical conditions again. Seventy-seven percent (17/22) of eligible patients >5 years of age felt good during the investigation. By changing our sedation policy, we could reduce the sedation rate from 27.1% to 7.5% (p < 0.0001; OR 0.219 95% CI 0.111–0.423). Conclusion: The evaluation of child friendly examination protocols demonstrated high reliability and patient satisfaction using situational sedation with a relatively high proportion of patients being sedated. Through protocol adaption with clear age limits, individual indication and education of staff, as well as the use of optimized sedatives, the need for sedation could be further reduced whilst maintaining a high patient satisfaction.

Targeted Indication of Imaging for Detection of Vesicoureteric Reflux after Pediatric Febrile Urinary Tract Infections Based on a Multiparametric Computational Tool

OBJECTIVES

Diagnostic workup after febrile urinary tract infections (fUTIs) in children remains a matter of debate. The authors aimed to evaluate multiple parameters in order to design a predictive tool enabling a targeted indication of voiding cystourethrography (VCUG).

METHODS

Records of 383 consecutive children who underwent a VCUG as well as a dimercaptosuccinic-acid (DMSA) scan after febrile urinary tract infections (fUTIs) at a single institution between 04/2009 and 06/2014 were reviewed. Twenty parameters were recorded. After regression analysis, 6 parameters were incorporated into a computational tool aiming at a targeted indication of an eventual VCUG. The performance of the tool was prospectively tested on 100 patients.

RESULTS

Postpyelonephritic alterations on DMSA, duplex systems, age 1-3 y, duration of fever >3 d, >2 fUTIs before VCUG and abnormal sonography findings were identified as significant predictors (p < 0.05 each); the presence of bladder and bowel dysfunction (BBD) was negatively associated with vesicoureteric reflux (VUR). The resulting computational tool achieved an Area under the curve (AUC) of 0.686 (CI 0.633-0.740). Prospective evaluation (100 new patients) revealed a sensitivity of 85.1%, a specificity of 49.1%, a positive predictive value of 59.7% and a negative predictive value of 78.7%.

CONCLUSIONS

The differentiated indication of a VCUG based on the use of a tool was efficient in optimizing the specificity of the diagnostic algorithm after fUTIs. The tool outperformed other common clinical approaches in terms of VUR detection and VCUG frequency. After validation and further refinement in a multicentric approach, this strategy could significantly enhance VUR detection whilst reducing the number of VCUGs.

Low-dose antibiotic prophylaxis has no significant impact on the stability of the intestinal microbiome in children with urogenital tract malformations under 1 year of age

INTRODUCTION

Accumulating data point at potentially lasting effects of early childhood therapeutic antibiotic exposure on the intestinal microbial. Little is known on the impact of low-dose longterm antibiotic prophylaxis on the developing intestinal microbiota in children during their first year of life.

OBJECTIVE

To investigate compositional changes of the intestinal microbiota by next generation sequencing based microbiome analysis and bacterial metabolites in longitudinally collected fecal samples.

STUDY DESIGN

Twelve patients were analyzed in this prospective, longitudinal pilot study during a period of 70 days (sampling on days 0,7,14,30,70). Only transvaginally and term born babies, breastfed with no prior antibiotic exposure with urogenital malformation (vesicoureteral reflux and/or upper urinary tract dilatation) were included into the study. Seven patients received antibiotic longterm prophylaxis with a second-generation cephalosporin and five did not. Sequencing of bacterial 16 S rRNA allowed for an analysis of the microbiome composition. The Principal coordinate analysis was performed for the evaluation of compositional profile. Furthermore, quantitative measurement of short chain fatty acids served as a proxy for the metabolic activity of the individual microbiome over the study time.

RESULTS

Analysis of observed species, Shannon Index and weighted Unifrac distances between timepoints revealed neither significant difference comparing the prophylaxis group versus the control group over the study period, nor significant changes within the groups over time. Principal coordinate analysis (PCoA) was performed for the evaluation of compositional profile. Also, no differences regarding the fecal SCFA content were found between the two groups (>0.05 at each tested point, Mann-Whitney Test).

DISCUSSION

Although there were interindividual compositional differences of the microbiome (cluster of bacterial composition) at the beginning of the observation, we did not observe significant longitudinal changes regarding both bacterial diversity and SCFAs in neither group. Over the study period, the patient's microbiome remained stable and resilient to the antibiotic exposure in terms of bacterial abundance and metabolism. Limitations to the study are the low number of patients included and the use of one single antibiotic (cefaclor).

CONCLUSION

This is the first pilot study to demonstrate that long term low-dose antibiotic administration in children under one year of age does neither seem to influence the composition of the intestinal microbiota nor the quantities of bacterial fermentation products compared to untreated controls.

[Surgical treatment of vesicoureteral reflux in the first year of life?]

Surgical intervention in children with VUR is rarely indicated in the first year of life. Early surgical intervention is primarily required for male infants with a high-grade reflux, renal impairment due to reflux nephropathy, infravesical obstruction and breakthrough infections like pyelonephritis or urosepsis. Besides the recommended circumcision, this is usually limited to endoscopic infravesical disobstruction of posterior urethral valves, prolapsing ureteroceles or secondary bladder neck obstructions. Concomitant endoscopic reflux therapy with bulking agents such as hyaluronic acid/dextranomer should be regarded as a downstaging of the VUR; the decision should be made on an individual basis. Urinary diversion, e. g. vesicostomy or ureterocutaneostomy, is only required in exceptional cases.

Is there a need for endoscopic evaluation in symptomatic boys with an unsuspicious urethra on VCUG? A consideration of secondary radiologic signs of posterior urethral valves

INTRODUCTION

A significant proportion of PUV becomes symptomatic after the perinatal period. Voiding cystourethrography (VCUG) often fails to identify PUVs. This study evaluates the relationship between the radiological appearance of the posterior urethra, potential secondary radiological signs and endoscopically documented PUV in boys with febrile UTIs, VUR, refractory symptoms of bladder overactivity or suggestive sonography findings.

PATIENTS AND METHODS

Data on VCUG findings and endoscopy from 92 boys (mean age 27 months) who underwent endoscopic PUV incision between 2012 and 2017 following a VCUG were reviewed. 24 boys with endoscopically unsuspicious urethras were included as control group (mean age 27.5 months). Statistical analysis was performed using Fisher's exact test.

RESULTS

In patients with PUV, the urethra was suspicious on a preoperative VCUG in 45.7%, whereas it appeared normal in 54.3%. Abortive forms of PUV were more frequently found in patients with a radiologically unsuspicious urethra (30%vs.16.7%, p = 0.15). Bladder neck hypertrophy on VCUG (16.7%vs.60.9%, OR 7.5, p < 0.001), a trabeculated bladder on VCUG (72%vs.37.5%, OR 4.3, p < 0.001) and a hypertrophied musculus interuretericus (38%vs.4.2%, OR 11.7, p < 0.001) were more common in patients with PUV and urethras appearing normal on VCUG as compared to controls.

CONCLUSION

Unsuspicious findings of the urethra on VCUG cannot exclude a relevant PUV and implicate a risk of disregarding abortive forms. The presence of secondary radiologic signs of infravesical obstruction on a VCUG despite an unsuspicious posterior urethra in boys with recurrent UTI's as well as refractory symptoms of bladder overactivity or suggestive signs on sonography must be further clarified endoscopically.

Ureteroureterostomy in patients with duplex malformations: does a large diameter of the donor ureter affect the outcome?

INTRODUCTION

Ureteroureterostomy is a commonly adopted, minimally invasive approach in the management of duplex anomalies requiring diversion, e.g., ectopic upper pole ureters.

OBJECTIVE

The authors hypothesized that a large diameter of the donor ureter could affect the outcome of this procedure.

STUDY DESIGN

Forty-two patients from two centers were retrospectively reviewed. To compare patients with small (group 1) vs large donor ureters (group 2), they were split at the median of the sonographically measured diameter at the level of the future anastomosis (n = 20 < 1.2 cm, mean 0.71 cm vs n = 22 ≥ 1.2 cm, mean 1.75 cm; P < 0.001) Figure. Ureteroureterostomy was performed in an end-to-side fashion with the donor ureter being tapered if required.

RESULTS

There was no significant difference in operation time (127 vs 121 min; P = 0.59) or duration of hospital stay (4.15 vs 4.09 days; P = 0.89) or number of postoperative complications (3 febrile urinary tract infections [fUTIs] in group 1 and one fUTI in group 2, P = 0.33). Reoperations during follow-up (1 stump resection and 2 endoscopic vesicoureteral reflux procedures) occurred exclusively in group 1 (P = 0.22). The mean pre-operative hydronephrosis grade of the affected moiety was higher in group 2 compared with group 1 (mean 2.73 Society for Fetal Urology classification [SFU] vs 1.65, P < 0.001). During follow-up, the mean hydronephrosis grade in group 2 improved from 2.73 to 1.36 SFU (P = 0.0011). In patients from group 1, the mean hydronephrosis grade remained relatively unchanged, from 1.65 to 1.35 SFU (P = 0.4).

DISCUSSION

After its first description in 1928, it took almost 40 years for ipsilateral ureteroureterostomy to become a widely adopted technique in the management of duplex malformations, especially for obstructive or ectopic upper pole moieties. Whereas it has been recently shown that the upper pole function does not seem to matter, there are still only narrative reports about the influence of the donor ureter diameter contributing to potential complications such as a de novo hydronephrosis of the receiving ureter with potential damage of the healthy moiety or the persistence of a pre-operatively marked hydronephrosis. While the study data are retrospective, the authors could demonstrate that a ureteral diameter of ≥1.2 cm is not factoring adversely into the occurrence of postoperative complications.

CONCLUSION

A donor ureter diameter ≥1.2 cm in ureteroureterostomy was not associated with a higher complication rate or worse outcome considering further fUTIs or reoperations. The postoperative reduction in hydronephrosis grade was more pronounced in patients with large donor ureters with disappearance of the pre-operative significant difference between the two groups.

Langerhans cells in hypospadias: an analysis of Langerin (CD207) and HLA-DR on epidermal sheets and full thickness skin sections

BACKGROUND

Hypospadias are among the most common genital malformations. Langerhans Cells (LCs) play a pivotal role in HIV and HPV infection. The migration of LC precursors to skin coincides with the embryonic period of hypospadias development and genetic alterations leading to the formation of hypospadias impact the development of ectodermally derived tissues. We hypothesized that this might be associated with a difference in frequency or morphology of epidermal and dermal LCs in hypospadias patients.

METHODS

A total of 43 patients from two centers were prospectively included into this study after parental consent and ethics approval. Epidermal and dermal sheets were prepared from skin samples of 26 patients with hypospadias, 13 patients without penile malformations and 4 patients with penile malformations other than hypospadias. Immunofluorescence staining of sheets was performed with anti-HLA-DR-FITC and anti-CD207/Langerin-A594 antibodies. Skin sections from 11 patients without penile malformation and 11 patients with hypospadias were stained for Langerin. Frequencies as well as morphology and distribution of epidermal and dermal LCs on sheets and sections were microscopically evaluated. Cell counts were compared by unpaired t-tests.

RESULTS

There was no difference in frequency of epidermal LCs, Neither on sheets (873 ± 61 vs. 940 ± 84LCs/mm², p = 0.522) nor on sections (32 ± 3 vs. 30 ± 2LCs/mm², p = 0.697). Likewise, the frequency of dermal LCs (5,9 ± 0,9 vs. 7.5 ± 1.3LCs/mm², p = 0.329) was comparable between patients with hypospadias and without penile malformation. No differences became apparent in subgroup analyses, comparing distal to proximal hypospadias (p = 0.949), younger and older boys (p = 0.818) or considering topical dihydrotestosterone treatment prior to surgery (p = 0.08). The morphology of the LCs was not different comparing hypospadias patients with boys without penile malformations.

CONCLUSIONS

LCs are present in similar frequencies and with a comparable morphology and distribution in patients with hypospadias as compared to children without penile malformations. This suggests that patients with hypospadias are not different from patients with normal penile development considering this particular compartment of their skin immunity.

Late ascended testes: is non-orthotopic gubernacular insertion a confirmation of an alternative embryological etiology?

INTRODUCTION

Re-ascended testes account for a proportion of all undescended testes (UDTs); one main hypothesis relating to their etiology relates to a patent processus vaginalis peritonei. The aim was to investigate gubernacular insertion points in boys with late ascended testis as a possible guide to an alternative embryological etiology.

PATIENTS AND METHODS

Patients with proven ascended testes were recruited from four different pediatric urology centers between May 2016 and September 2017. All patients were evaluated regarding their gubernacular insertion during orchidopexy. The presence of accompanying patent processus vaginalis and the association between the epididymis and testis were also documented.

RESULTS

Seventy-seven children (mean age = 73.1 ± 41.2 months [range 18-176]) were enrolled into the study. A non-orthotopic gubernacular insertion point was found in 96.1% (n = 74); 34.2% (n = 26) of these were located in the groin and 63.2% (n = 48), high within the scrotum. Figure A. An open processus vaginalis peritonei was found in 35.1%. Twelve patients (15.6%) had small, dysplastic appearing testis with testis-epididymis dissociation. Boys with a higher insertion of the non-orthotopic gubernaculum (n = 48, groin) were operated earlier (mean age at surgery, 62.3 months) compared with those with a gubernacular insertion at a high scrotal site (mean age at surgery, 90.5 months; p = 0.004). Figure B.

DISCUSSION

This study revealed that non-orthotopic gubernacular insertion is found in the vast majority of the ascending testis cases. Patent processus vaginalis was accompanying only 35.1% of all children and might be the cause of the ascending testis in this small subgroup of patients in line with the earlier reports [1]. In boys with ascending testes, in this population, the gubernaculum was very likely to insert non-orthotopically. In concordance with previous reports [2] and regarding the finding of a an earlier age at surgery in boys with higher inserting gubernacula, this could provide a logical explanation as to how these testes are initially palpable in the scrotum and then, during body growth are retracted to the groin.

CONCLUSION

In 96.1% of the patients, a non-orthotopic gubernacular insertion was found. This points to embryologic etiology, complying well with earlier reports and further underlining the critical importance of timely diagnosis and treatment for this group of patients.

Standardization of pediatric uroradiological terms: a multidisciplinary European glossary

To promote the standardization of nephro-uroradiological terms used in children, the European Society of Paediatric Radiology uroradiology taskforce wrote a detailed glossary. This work has been subsequently submitted to European experts in pediatric urology and nephrology for discussion and acceptance to improve the quality of radiological reports and communication between different clinicians involved in pediatric urology and nephrology.

Standardization of pediatric uroradiological terms: A multidisciplinary European glossary

To promote the standardization of nephro-uroradiological terms used in children, the European Society of Pediatric Radiology uroradiology taskforce wrote a detailed glossary. This work has been subsequently submitted to European experts in pediatric urology and nephrology for discussion and acceptance to improve the quality of radiological reports and communication among different clinicians involved in pediatric urology and nephrology.

The method of urine sampling is not a valid predictor for vesicoureteral reflux in children after febrile urinary tract infections

INTRODUCTION

The likelihood of detecting vesicoureteral reflux (VUR) after febrile urinary tract infections (UTI) in children logically should correlate with the correct diagnosis of the UTI. Beneath the unspecific symptoms of fever urine analysis is the main diagnostic criterion for the exact diagnosis of febrile UTIs in children. Use of inadequate urine sampling techniques during diagnosis may lead to impaired accuracy in UTI diagnosis. This could lead to the assumption that children, having diagnosed their UTI by the use of possibly inadequate urine sampling techniques should not be evaluated as consequently compared to those, where the diagnosis relied on sterile urine sampling techniques. We hypothesized that children with possibly contaminated urine samples during the initial diagnosis may show a lower rate of VUR in subsequent VCUGs because of a wrong diagnosis initially compared to children, where accurate urine sampling techniques were used.

PATIENTS

Between 2009 and 2014, a total of 555 patients underwent a primary VCUG at our department indicated because of febrile UTIs. Patients with urine collection methods other than bag urine and catheter/suprapubic aspiration (SPA) were excluded from this study (mid-stream urine, potty urine, n = 149). We evaluated 402 patients (male/female 131/271, mean age 1.91 years), VUR rates and grades were compared between patients where urine was sampled by the use of a urine bag only at the time of diagnosis (n = 296, 73.6%) and those where sterile urine sampling (catheter, suprapubic puncture) was performed (n = 106, 26.3%). 4 patients were excluded due to equivocal data on urine sampling.

RESULTS

VUR rate in children after sterile urine sampling using a catheter or SPA accounted to 31.1%. In those where urine samples acquired by the use of urine bags were used, 33.7% showed VUR on subsequent VCUG (p = 0.718). There were no significant differences as to VUR grades or gender, although VUR was much more commonly diagnosed in female patients (37.0% vs 28.2%, p = 0.227) (Figure).

CONCLUSION

Children diagnosed with their UTI by use of bag urine in our experience carried the same risk of showing a VUR in a subsequent VCUG compared to those, where the initial diagnosis relied - beneath clinical criteria - on urine samples acquired by suprapubic puncture or catheterization. Consequently urine-sampling technique during initial UTI diagnosis alone should not be used as predictor for the reliability of UTI diagnosis and should not influence the further management after UTI.

[Urosepsis in Children]

Urinary tract infections (UTI) are the most common infectious diseases in children. Urosepsis in childhood, though rare, is the most complicated possible variant. In newborns and infants, unspecific symptoms are a significant barrier to a fast and reliable diagnosis, which is crucial to successful treatment. In addition to urine and laboratory tests as well as non-invasive examinations (ultrasound), there may be an indication for invasive examinations of the kidneys (DMSA scans) in cases of a severe infection. Conservative therapy consists of targeted parenteral antibiotic treatment and paediatric sepsis management. Surgical desobstruction and urinary diversion are indicated if conservative therapy has failed. In addition to catheterised drainage of the upper and lower urinary tract, open surgery techniques are used in due consideration of the child and situation. Also, causal factors such as congenital malformations of the urinary system leading to impaired urinary drainage (vesicoureteral reflux, obstruction) have to be evaluated and treated.

Evaluation of Mathisen's technique for ureteral reimplantation in children with primary vesicoureteral reflux

INTRODUCTION

Although cross-trigonal ureteral reimplantation (Cohen) is a commonly used technique in children, it represents a non-physiological transfer of the ureteral orifices and may prove challenging with regard to endoscopic ureteral operations in later life. In 1964, Mathisen described an alternative method of ureteral reimplantation with lateralization of the neohiatus, creating an orthotopic course of the submucosal ureter. We have evaluated success and complication rates of both techniques that were applied sequentially at our departments.

METHODS

Forty-eight consecutive patients (83 ureters, 24 males/24 females) following Mathisen reimplantation were compared with 53 consecutive patients (98 ureters, 30 males/23 females) following Cohen reimplantation. Inclusion criteria were primary vesicoureteral reflux (VUR) and no previous intervention. Reflux grades (Mathisen 58 ureters/69.9% VUR ≥ III; Cohen 66 ureters/66.7% VUR ≥ III) and the occurence of other complicating factors (ureteroceles, megaureters, posterior urethral valves) in both groups were comparable.

RESULTS

After Cohen's reimplantation there were no immediate complications requiring intervention; during follow-up (mean 28.2 months) three patients (5.6%) suffered febrile urinary tract infections (UTIs), of which one (1.8%) was diagnosed with a persisting VUR. Persistent hydronephroses (≥II SFU) were recorded in six patients (13.2%). After reimplantation using Mathisen's technique, two patients (4.1%) suffered significant intravesical bleeding; during follow-up (mean 23.06 months) four patients (8.3%) suffered febrile UTIs, and seven patients (14.5%) were diagnosed with persisting VUR after a mean follow-up of 10.8 months. The patients with persistent VUR had more commonly high-grade (IV and V) VUR initially, compared to the whole group. Two patients (4.1%) had persistent hydronephroses (≥II SFU). Mathisen's technique for ureteral reimplantation yielded a significantly (p = 0.0256 patients, p = 0.006 ureterorenal units) lower success rate (85.5% patients, 89.2% ureterorenal units) in comparison with Cohen's technique (98.2% patients, 99% ureterorenal units). Although there was no intervention for obstruction, persistent hydronephrosis was more common in the Cohen group (13.2% vs. 4.1%, n.s.).

CONCLUSIONS

Despite the advantages of an orthotopic ureteral orifice close to the bladder neck, as achieved by Mathisen's reimplantation, cross-trigonal ureteral reimplantation proved more reliable for VUR correction. As regards optimizing the results, patient selection for either technique could prove essential. Nevertheless, as regards the difficulties with ectopic ureteral orifices in the Cohen technique in the long-term follow-up, the concept of anatomic, orthotopic ureteral reimplantation should be pursued and the technique should be further refined.

[Disorders of sex development and proximal hypospadias]

BACKGROUND

Children with ambiguous genitalia due to different chromosome or gonadal sex are a particular challenge concerning the diagnostic and therapeutic implications. Proximal hypospadias patients with normal gonadal development should be distinguished from children with DSD (disorders of sex development) to guarantee normal gender identity and the best possible surgical therapy.

OBJECTIVES

This paper focuses on the terminology, embryology, and pathophysiology of the different manifestations of DSD. The state of knowledge about this disease pattern with particular emphasis on proximal hypospadias based on national and international scientific discussions is presented.

MATERIALS AND METHODS

The different clinical pictures as well as therapeutic options of DSD with a special focus on recent literature and giving particular attention to patients with proximal hypospadias are presented.

RESULTS

Because of the complexity of patients suffering from disorders of sex development an interdisciplinary DSD healthcare team including a paediatric endocrinologist as well as paediatric urologist should be provided. These specialists enable an accurate diagnosis in severe hypospadias patients without reference to DSD diseases patterns.

Persistence and recurrence of vesicoureteric reflux in children after endoscopic therapy - implications of a risk-adapted follow-up

Introduction

There is no well-defined follow-up scheme available to reliably detect persistent or recurrent vesicoureteric reflux (VUR) after endoscopic therapy (ET), but also to reduce postoperative invasive diagnostics in these children.

Our aim was the evaluation of possible predictors of persistence and recurrence of VUR, in order to elaborate and test a risk-adapted follow-up regimen.

Material and methods

92 patients (85/92%f, 7/8%m, age 2.99y) underwent direct isotope cystography (DIC) three months after ET. Persistent or recurrent VUR, scarring on dimercaptosuccinic acid (DMSA) scans and further fUTIs after therapy (follow-up 24.6 m) were documented and analysed.

Results

VUR persistence 3 months after ET was found in 11 (11.9%) patients; recurrent VUR in 4 (4.3%) patients. Scarring on preoperative DMSA and dilating VUR (°III and °IV) were significantly associated with recurrent VUR. If only children with preoperative positive DMSA scan or dilating VUR would have undergone DIC, only 58/92 DICs (64%) would have been necessary. Only 45.5% of otherwise detected VURs would have been identified using this risk-adapted strategy.

Conclusions

Limiting invasive follow-up diagnostics (VCUG) and, therewith, the radiation burden in a predefined group of patients at risk for persistence or recurrence of VUR is not recommended, due to the significant chance of missing persistent or new onset contralateral VUR. Therefore, we recommend a routine follow-up VCUG after ET. Further prospective scientific efforts to evaluate new, alternative factors influencing persistence and recurrence of VUR, in order to establish an effective follow-up strategy, are warranted.

Lower radiation burden in state of the art fluoroscopic cystography compared to direct isotope cystography in children

INTRODUCTION

Both, fluoroscopic voiding cystourethrography (fVCUG) and direct isotope cystography (DIC) are diagnostic tools commonly used in pediatric urology. Both methods can detect vesicoureteral reflux (VUR) with a high sensitivity. Whilst the possibility to depict anatomical details and important structures as for instance the urethra in boys or the detailed calyceal anatomy are advantages of fVCUG, a lower radiation burden is thought to be the main advantage of DIC. In the last decade, however, a rapid technical evolution has occurred in fluoroscopy by implementing digital grid-controlled, variable rate, pulsed acquisition technique. As documented in literature this led to a substantial decrease in radiation burden conferred during fVCUGs.

OBJECTIVE

To question the common belief that direct isotope cystography confers less radiation burden compared to state of the art fluoroscopic voiding cystography.

STUDY DESIGN

Radiation burden of direct isotope cystography in 92 children and in additional 7 children after an adaption of protocol was compared to radiation burden of fluoroscopic voiding cystourethrography in 51. The examinations were performed according to institutional protocols. For calculation of mean effective radiation dose [mSv] for either method published physical models correcting for age and sex were used. For DIC the model published by Stabin et al., 1998 was applied, for fVCUG two different physical models were used (Schultz et al., 1999, Lee et al., 2009).

RESULTS

The radiation burden conferred by direct isotope cystography was significantly higher as for fluoroscopic voiding cystourethrography. The mean effective radiation dose for direct isotope cystography accounted to 0.23 mSv (± 0.34 m, median 0.085 mSv) compared to 0.015 mSv (± 0.013, median 0.008 mSv, model by Schultz et al.) - 0.024 mSv (± 0.018, median 0.018 mSv, model by Lee et al.) for fluoroscopic voiding cystourethrography. After a protocol adaption to correct for a longer examination time in DIC that was caused by filling until calculated bladder capacity, mean radiation burden accounted to .07 mSv (median 0.07 mSv) and the values were less scattered.

DISCUSSION

As it had to be expected from literature, radiation dose from fVCUG, if modern image acquisition techniques are used, is even less than from DIC. In our protocol, according to nuclear medicine standards, bladders were filled until calculated capacity. This resulted in a longer examination time for the patients with a higher functional capacity, resulting in relatively higher radiation burden. However, also if the protocol is changed or only the patients with relatively fast bladder emptying are considered, radiation burden conferred by DIC is higher (at least × 2.9, comparing the "worst" case for fVCUG with the "best" case for DIC). Absolute radiation burden conferred by either exam is extremely low compared to other medical radiation exposures as well as to environmental radiation. Consequently it is most probably not relevant for the individual childs future risk for cancer or other radiation damage. However, because of repeated investigations with correspondingly higher radiation burden in this patient group the ALARA (as low as reasonably achievable) principle should lead to a optimized use of fVCUG rather than an uncritical use of DIC, given that modern acquisition standards are available and radiation measurement is performed. Also, fVCUG provides more information concerning anatomical details compared to DIC.

CONCLUSION

Contrary to common beliefs, effective radiation dose conferred during fluoroscopic voiding cystourethrography is significantly lower than during direct isotope cystography. The prerequisite for our findings, however, is the use of modern image acquisition tools and an optimized protocol. Both exams confer low radiation doses probably only relevant to children undergoing repeated radiation exposure. Nevertheless, this findings should be considered in indication for either exam in order to reduce the radiation burden to a minimum whilst optimizing the information yield.

Clinical outcome after endoscopic therapy for occult vesicoureteral reflux in females: preliminary results of a retrospective case series

OBJECTIVE

The aim of this study was to evaluate the clinical outcome after endoscopic therapy by injection of bulking agent in the treatment of occult vesicoureteral reflux (VUR) [no VUR on standard voiding cystourethrography (VCUG), but positive (99m)Tc-2,3-dimercaptosuccinic acid (DMSA) scan] in females who have recurrent febrile urinary tract infections (UTIs).

MATERIAL AND METHODS

A case series was retrospectively identified of 24 females (mean age 15.5 years) with negative VCUG, but renal scars in one (n = 4) or both (n = 20) kidneys on DMSA scan. Endoscopic injection was performed bilaterally in 20 (83.3%) and unilaterally in four patients (16.7%). The incidence of postoperative UTIs was documented with a mean follow-up of 2.5 years (range 1-6 years).

RESULTS

The mean renal part function (DMSA scan) on the left and right sides was 53.5% (15-74%) and 47.3% (26-85%), respectively. Twenty-one out of 24 patients (87.5%) showed no evidence of any febrile UTIs postoperatively. One patient (4.2%) experienced a further febrile UTI 6 months after treatment. Two other patients (8.3%) had one questionable afebrile UTI, 4 and 3 years after therapy. Pressure-flow electromyography confirmed a dysfunctional voiding pattern in 12 patients (50%) treated with pelvic floor therapy and behavioural interventions before endoscopic therapy.

CONCLUSIONS

Injection of bulking agent seems to be a suitable treatment for occult VUR in females to prevent further febrile UTIs. Patients with occult VUR should undergo a careful evaluation of possible urodynamic disorders such as dysfunctional voiding. These findings should be studied in prospective trials before drawing any conclusions.

Gender-related fetal development of the internal urethral sphincter

OBJECTIVE

To investigate the fetal development of the internal urethral sphincter and the gender-related morphologic differences of the bladder outlet.

MATERIALS AND METHODS

Thirty-seven (14 female, 23 male) fetal bladder neck specimens (mean gestational age, 19.4 weeks) with the smooth muscle complex of the internal sphincter were investigated histologically. After immunostaining serial sections in 3 reference planes (sagittal, frontal, and horizontal) of the bladder neck, the internal sphincter volumes and bladder outlet diameters were measured and correlated with gender and age of gestation.

RESULTS

Between the 18th and 40th week of gestation, an exponential growth of the internal sphincter muscle with significant higher volumes could be observed in male fetuses compared with female fetuses (internal sphincter volumes, P = .006; radius of the sphincter complex, P = .001). As a result of this gender difference, the bladder outlet was significantly (P = .001) narrower in male than in female fetuses. Moreover, we found a significant positive correlation between age and all measured parameters in both male and female specimens.

CONCLUSION

The present study indicates a significant closer bladder outlet in male fetuses compared than in females. It thereby provides evidence of a gender-related functional obstruction in addition to a suppositious transient infravesical obstruction in male human fetuses.

Autologous fibroblast transplantation at the vesico-ureteral junction as potential reconstructive cell replacement in an animal model

PURPOSE

To evaluate the cellular survival of donor fibroblasts after transplantation at the vesico-ureteral junction (VUJ) and to analyse their potential for reconstructive cell replacement in an animal model as autologous fibroblasts have been used as soft tissue augmentation material for scared and damaged tissue.

METHODS

Muscles biopsies were procured from the lower limb muscles of 4 pigs; cytoplasm of fibroblasts was labelled with nano-sized iron oxide particles. Six weeks after taking of the muscle biopsies, fibroblast transplantation was performed, 3 × 10(6) cells suspended in transplantation medium (in 1-ml syringes) were injected at the VUJ using the modified STING technique. Animals were killed 8 weeks later; seeded fibroblasts were identified using prussian blue staining protocol; histological evaluation and morphological analysis were performed by light microscopy (Mayer's haematoxylin-eosin staining); and bladders were scanned by MRI for visualization and localization of the iron-labelled donor cells.

RESULTS

Donor fibroblast cell colonization and cellular viability at the VUJ was demonstrated by MRI and histochemically indicating cellular uptake of iron particles at the VUJ. It was also evident that transplanted fibroblasts integrate into the extracellular matrix of the distal ureter augmenting ureteral host tissue.

CONCLUSIONS

Labelled implanted autologous fibroblasts were visualized by staining procedure as well as MRI scan demonstrating persistence at the VUJ, suggesting that in vitro expanded fibroblasts survived in vivo after transplantation.

Embryology and anatomy of the vesicoureteric junction with special reference to the etiology of vesicoureteral reflux

Concerning the ureterovesical junction - the region most important for the anti-reflux mechanism - there is still a lot of misunderstanding and misinterpretation with regard to normal fetal development. Data are scarce on possible causes of primary vesicoureteral reflux and on involved mechanisms of the so-called maturation process of refluxing ureteral endings. The ratio of the intravesical ureteral length to the ureteral diameter is obviously lower than assumed so far, as clearly revealed by some studies. Therefore it can be doubted that the length and course of the intravesical ureter is of sole importance in the prevention of reflux. Additionally refluxing intravesical ureteral endings present with dysplasia, atrophy, and architectural derangement of smooth muscle fibers. Besides, a pathologically increased matrix remodeling combined with deprivation of the intramural nerve supply has been confirmed. Consequently, symmetrical narrowing of the very distal ureteral smooth muscle coat creating the active valve mechanism to defend reflux is not achievable. It is apparent that primary congenital vesicoureteral reflux seems to be the result of an abnormality within the ureterovesical junction with an insufficient muscular wrap. Nature is believed to establish much more sophisticated mechanisms than the so-called passive anti-reflux mechanism. Remodeling processes within the ureterovesical junction of refluxing ureteral endings support that maturation itself is nothing else than wound or defect healing and not a restitution of a morphological normal ureterovesical junction. Lacking the nerve supply a restoration of any muscular structure can not be achieved.

Endoscopic treatment of vesicoureteral reflux using dextranomer/hyaluronic acid copolymer in children: results of postoperative follow-up with real-time 3D sonography

OBJECTIVES

We evaluated whether real-time 3D ultrasound (4D-US) together with clinical evaluation is an alternative to voiding cystourethrography (VCUG) after endoscopic treatment of vesicoureteral reflux (VUR) in children at postoperative follow-up.

MATERIAL AND METHODS

We reviewed 178 children who underwent endoscopic therapy with dextranomer/hyaluronic acid copolymer in grade II or III VUR between 2002 and 2005. 4D-US was performed in all patients 1 day and 3, 9 and 18 months after endoscopic therapy. Only children with postoperative urinary tract infections (UTIs) and/or nonorthotopic position of the bulking agent were referred for VCUG.

RESULTS

In 93% of the ureteral units, the depot could be detected in the orthotopic position after 3, 9 and 18 months. None of these children developed UTIs in the postoperative follow-up. Twelve children demonstrated a shifting of the depot, indicating a possible therapy failure. Eight of these 12 patients (66.7%) presented a positive VCUG, and 50% of them sustained UTIs.

CONCLUSIONS

4D-US seems to be a sufficient protocol in the follow-up of children after endoscopic treatment of low-grade VUR. VCUG should be performed in cases of a shifted position of the depot; invasive investigations are unnecessary in asymptomatic children with orthotopic bulk.

Self-assembled InAs/GaAs quantum dots covered by different strain reducing layers exhibiting strong photo- and electroluminescence in 1.3 and 1.55 microm bands

The effect of different InGaAs and GaAsSb strain reducing layers on photoluminescence and electroluminescence from self-assembled InAs/GaAs quantum dots grown by metal-organic vapour phase epitaxy was investigated. The aim was to shift their luminescence maximum towards optical communication wavelengths at 1.3 or 1.55 microm. Results show that covering by InGaAs strain reducing layer provides stronger shift of photoluminescence maximum (up to 1.55 microm) as compared to GaAsSb one with similar strain in the structure. This is caused by the increase of quantum dot size during InGaAs capping and reduction of quantum confinement of the electron wave function which spreads into the cap. Unfortunately, the weaker electron confinement in quantum dots is a reason of a considerable blue shift of electroluminescence from these InGaAs structures since optical transitions move to InGaAs quantum well. Although strong electroluminescence at 1300 nm was achieved from quantum dots covered by both types of strain reducing layers, the GaAsSb strain reducing layer is more suitable for long wavelength electroluminescence due to higher electron confinement potential allowing suppression of thermal carrier escape from quantum dots.

5-alpha-reductase and the development of the human prostate

During the 10^th week of gestation human prostate development is about to start. Androgens are the crucial factors to stimulate the initial interactions between the epithelium and mesenchyme. One of the key events in androgen metabolism is the transformation of circulating testosterone to 5α-dihydrotestosterone (DHT) by tissue-linked 5α-reductase. Both, the formation of a male phenotype and the androgen-mediated growth of the prostate are mediated by DHT. To date the function of 5α-reductase 1 (5αR1) still remains unclear whereas 5α-reductase 2 (5αR2) is supposed to be the predominant isoenzyme in human accessory sex tissue. Only little data are available on the detection, distribution, and effects of both isoenzymes during fetal life and infancy. Recently, immunohistochemical investigations of serial sections from fetuses and infants using specific antibodies directed against 5αR1 and 5αR2 seem to shed light on that issue. Moreover, the detection of downstream products of androgen synthesis using RT-PCR analyses for 17-β hydroxysteroid dehydrogenase Type 2 (17 βHSD 2), 17 βHSD Type 3 and 17 βHSD Type 7 adds to discovering the molecular biological background. New studies confirm that both isoenzymes are present throughout fetal development. On the transcriptional level RT-PCR for 5αR1 and 5αR2 certifies these findings. 17 βHSD 2, 3 and 7 representing the most relevant enzymatic downstream products of cellular androgen synthesis were revealed by RT-PCR as well. Current studies discovered the expression and distribution of both 5α-reductase isoenzymes as well as the potential contribution of 5αR1 during fetal human prostate development.

Chemistry and pharmacology of neglected helminthic diseases

Neglected helminthic diseases cause many social, economic and health care challenges in developing countries. The high number of patients suffering from these parasitic infections and the lack of sufficient treatment options represent severe problems. Research on new drugs and therapies to meet this urgent requirement has to be intensified. This review focuses on infections caused by four helminthic parasites, which have been declared as neglected diseases by the World Health Organization: namely drancunculiasis, lymphatic filariasis, onchoceriasis, and schistosomiasis. They show a considerable overlap in their world-wide prevalence and treatment strategies. Nevertheless, treatment is not without complications. The most efficient lymphatic filariasis drug, diethylcarbamazine, causes severe adverse effects in onchocerciasis patients and completely fails in the treatment of drancunculiasis. In this review, we discuss these incongruities at the molecular and cellular level. Furthermore, established or investigational drug combination regimens are highlighted. In the past years, progress has been made in the area of schistosomiasis and onchocerciasis. The molecular biology of underlying mechanisms, signalling pathways and related targets affected by drug therapy are discussed in detail. Finally, successful treatment strategies and remaining future challenges are summarized.

An atomistic J-integral at finite temperature based on Hardy estimates of continuum fields

In this work we apply a material-frame, kernel-based estimator of continuum fields to atomic data in order to estimate the J-integral for the analysis of an atomically sharp crack at finite temperatures. Instead of the potential energy appropriate for zero temperature calculations, we employ the quasi-harmonic free energy as an estimator of the Helmholtz free energy required by the Eshelby stress in isothermal conditions. We employ the simplest of the quasi-harmonic models, the local harmonic model of LeSar and co-workers, and verify that it is adequate for correction of the zero temperature J-integral expression for various deformation states for our Lennard-Jones test material. We show that this method has the properties of: consistency among the energy, stress and deformation fields; path independence of the contour integrals of the Eshelby stress; and excellent correlation with linear elastic fracture mechanics theory.

Endoscopic application of dextranomer/hyaluronic acid copolymer in the treatment of vesico-ureteric reflux after renal transplantation

OBJECTIVE

• To evaluate the success of endoscopic dextranomer/hyaluronic acid copolymer (DHAC) application in the treatment of patients with recurrent urinary tract infections (UTIs) and vesico-ureteric reflux (VUR) into the transplanted graft after renal transplantation.

PATIENTS AND METHODS

• Between January 2008 and April 2009, 19 patients with recurrent UTIs presented VUR proven by voiding cystourethrography. • To correct VUR of the transplanted ureter, DHAC was injected endoscopically using hydrodistention technique. • Pre- and postoperative serum creatinine levels, the number of pre- and postoperative UTIs, postoperative complications and reflux resolution rate were recorded. The mean follow-up was 6.5 months.

RESULTS

• The average number of UTIs was reduced significantly from 4.89 (range 2-14) to 1.31 (range 0-4) on pre- and postoperative follow-up, respectively, of 6 months (P < 0.001). The success rate increased from 57.9% after the first injection to 78.9% after the second injection. • The remaining four patients with residual VUR received long-term low dose antibiotic prophylaxis. In total, two (10.5%) patients developed increasing creatinine levels postoperatively as a result of distal ureteral obstruction, and temporary urinary drainage was necessary in both patients.

CONCLUSIONS

• DHAC appears to be an efficient and minimal invasive method for treating VUR after renal transplantation with respect to short-term success. • Further investigation with a larger group of patients and longer follow-up is needed to evaluate the prolonged effect, as well as any potential side effects.

Extracellular matrix degradation and reduced neural density in children with intrinsic ureteropelvic junction obstruction

OBJECTIVES

To investigate the extracellular matrix microenvironment and nerve supply of ureteropelvic junctions (UPJs) in children with intrinsic UPJ obstruction. Congenital UPJ obstruction is the most common cause of neonatal hydronephrosis. Although many studies investigating the molecular changes within this segment have been performed, the underlying mechanisms of UPJ obstruction are still unclear.

METHODS

Specimens were obtained from 21 children with a mean age of 103.2 months undergoing dismembered pyeloplasty. Control samples included 9 archival specimens from age-matched children without any history of urologic disease. Paraffin-embedded sections were immunostained to detect matrix metalloproteinase 2 (MMP-2), tenascin C (TN-C), and S-100 (for the neuronal supply). Expression patterns were investigated using semiquantitative high-power field magnification analyses, and the MMP-2 and TN-C immunoreactivity were scored. Differences between the 2 groups were examined statistically.

RESULTS

All UPJ specimens displayed a resolved muscular coat and replacement of smooth muscle cells by connective tissue. The degree of MMP-2 expression representing matrix turnover was statistically significantly elevated. Similarly, TN-C expression was found to be higher in obstructed specimens. Additionally, the mean S-100 staining was lower than in controls. Although S-100-positive nerve-fibers were more predominant in the adventitia with minimal submucosal and absent intramuscular staining in patient specimens, they were abundant in both adventitia and submucosa with minimal intramuscular staining in the controls.

CONCLUSIONS

In intrinsic UPJ obstruction samples, a dissolved smooth muscular coat and an overexpression of extracellular matrix proteins, together with depleted nerve supply, was demonstrable.

Bisulfite-based methylation analysis of imprinted genes

Genomic imprinting is an epigenetically controlled form of gene regulation leading to the preferential expression of one parental gene copy. To date, approximately 40 imprinted genes have been described that are exclusively or predominantly expressed from either the paternal or the maternal allele (www.mgu.har.mrc.ac.uk/imprinting/implink.html). Changes in the imprinted expression of such genes result in developmental abnormalities; in the human they are associated with several diseases and various types of cancer (1-3).