Update and Summary of the European Association of Urology/European Society of Paediatric Urology Paediatric Guidelines on Vesicoureteral Reflux in Children

BACKGROUND AND OBJECTIVE

The prescriptive literature on vesicoureteral reflux (VUR) is still limited and thus the level of evidence is generally low. The aim of these guidelines is to provide a practical approach to the treatment of VUR that is based on risk analysis and selective indications for both diagnostic tests and interventions. We provide a 2023 update on the chapter on VUR in children from the European Association of Urology (EAU) and European Society for Paediatric Urology (ESPU) guidelines.

METHODS

A structured literature review was performed for all relevant publications published from the last update up to March 2022.

KEY FINDINGS AND LIMITATIONS

The most important updates are as follows. Bladder and bowel dysfunction (BBD) is common in toilet-trained children presenting with urinary tract infection (UTI) with or without primary VUR and increases the risk of febrile UTI and focal uptake defects on a radionuclide scan. Continuous antibiotic prophylaxis (CAP) may not be required in every VUR patient. Although the literature does not provide any reliable information on CAP duration in VUR patients, a practical approach would be to consider CAP until there is no further BBD. Recommendations for children with febrile UTI and high-grade VUR include initial medical treatment, with surgical care reserved for CAP noncompliance, breakthrough febrile UTIs despite CAP, and symptomatic VUR that persists during long-term follow-up. Comparison of laparoscopic extravesical versus transvesicoscopic ureteral reimplantation demonstrated that both are good option in terms of resolution and complication rates. Extravesical surgery is the most common approach used for robotic reimplantation, with a wide range of variations and success rates.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This summary of the updated 2023 EAU/ESPU guidelines provides practical considerations for the management and diagnostic evaluation of VUR in children.

ADVANCING PRACTICE

For children with VUR, it is important to treat BBD if present. A practical approach regarding the duration of CAP is to consider administration until BBD resolution.

PATIENT SUMMARY

We provide a summary and update of guidelines on the diagnosis and management of urinary reflux (where urine flows back up through the urinary tract) in children. Treatment of bladder and bowel dysfunction is critical, as this is common in toilet-trained children presenting with urinary tract infection.

Endoscopic dilatation/incision of primary obstructive megaureter. A systematic review. On behalf of the EAU paediatric urology guidelines panel

INTRODUCTION

Historically, ureteral reimplantation (UR) has been the gold standard for treatment of primary obstructive megaureter (POM) with declining renal function, worsening obstruction, or recurrent urinary tract infections. In infants, open surgery with reimplantation of a grossly dilated ureter into a small bladder, can be technically challenging with significant morbidity. Therefore, less invasive endoscopic management such as dilatation or incision of the ureter-vesical junction, has emerged as an alternative to reimplantation during the last decades.

OBJECTIVE

To systematically evaluate the effectivity, safety, and potential benefits of endoscopic treatment (dilatation with or without balloon or incision) of POM in comparison to UR.

STUDY DESIGN

A systematic review was conducted. Randomized controlled trials (RCTs), nonrandomized comparative studies (NRSs), and single-arm case series including a minimum of 20 participants and a mean follow-up more than 12 months were eligible for inclusion.

RESULTS

Of 504 articles identified, 8 articles including 338 patients were eligible for inclusion (0 RCTs, 1 NRSs, and 7 case series). Age at time of surgery was minimum 15 days to a maximum of 192 months. Indications for endoscopic treatment (ET) included patients with loss of split renal function (>10%) and worsening of hydroureteronephrosis. The studies analysed reported a success rate ranging from 35% to 97%. Success was defined as stabilization of differential renal function without further procedures. A post-operative complication rate of 23-60% was reported (mostly transient haematuria, urinary tract infections and stent migration or intolerance). In 14% of the cases salvage UR following initial ET, was performed due to relapse of symptomatic POM.

CONCLUSION

Endoscopic treatment for persistent or progressive POM in children is a minimally invasive alternative to UR with a long-term modest success rate. Additionally, it can be performed within a wide age span, with equal success rate and complication rates.

Surgical retrieval of transected umbilical vein catheter in an extremely preterm neonate

Umbilical catheters are used in the care of critically ill neonates for intravenous treatment. It is generally considered a safe procedure, although complications can occur. Of these, catheter breakage and intravenous migration are rare but potentially life-threatening events. Due to the low frequency of which these events occur, obtaining detailed descriptions of removal techniques can pose a challenge. Here, we describe a case of a broken umbilical vein catheter and the surgical retrieval of the retained fragment. We also present a thorough literature search of cases of broken umbilical catheters and the method by which they were removed.

Assessing timeline delays associated with utilization of ultrasound diagnostics in paediatric acute scrotum, pre and per COVID-19 pandemic

INTRODUCTION

Acute scrotum is a common presentation in the pediatric population and can indicate serious conditions such as testicular torsion, in which quick diagnosis and treatment is crucial for increasing the chances of a favorable outcome. During the COVID-19 pandemic, even patients with serious conditions, had delayed presentations and in-hospital management, resulting in worse outcomes.

OBJECTIVE

The aim of the study was to evaluate the safety of ultrasound in diagnosing pediatric acute scrotum and to identify delays from onset of symptoms until surgical exploration. Additionally, we wanted to gauge the impact of COVID-19 pandemic on delay and outcome.

METHODS

Medical records of patients aged 1-16 years seen with acute scrotum at the authors' University Hospital from 2017 to 2020 were reviewed, and 438 patients in 467 individual visits were included. Information on demographics, symptoms, ultrasound results, outcome, and time courses were retrieved and analyzed with regards to outcome and the presence COVID-19.

RESULTS

We did not find the use of ultrasound to increase the risk of orchiectomy (OR 2.259 (0.387-13.195)), however patients undergoing ultrasound had a significantly longer pre-hospital ischemia time, and therefore an increased orchiectomy rate. Delay between referral and presentation was the greatest predictor of orchiectomy in testicular torsion (OR 1.031 (1.003-1.060)), while in-hospital delay did not increase the risk of orchiectomy (OR 0.998 (0.992-1.004)). Time courses and outcome did not significantly differ before- and during the COVID-19 pandemic.

DISCUSSION

The primary contributor to ischemic time in testicular torsion was pre-hospital delay, and neither in-hospital delay nor the delay incurred by use of ultrasound affected the outcome. This might be explained by timely in-hospital management and ultrasound only being used selectively in patients with a lower clinical suspicion of testicular torsion and in those with prolonged symptom duration. During the COVID-19 pandemic, pre- and in-hospital delay as well as outcome did not differ significantly from pre-pandemic measures, which indicates that parents felt safe approaching the healthcare system, and resources were sufficient to handle this patient group in spite of an ongoing pandemic. The current study is limited by its retrospective design, and relatively small group of testicular torsion patients.

CONCLUSION

We found ultrasound to be safe in diagnosing pediatric acute scrotum. Furthermore, it can be inferred that measures aimed at reducing pre-hospital delay could potentially increase the salvage rate in testicular torsion. We did not find COVID-19 to affect either outcome or time to treatment in testicular torsion.

[Not Available]

Paediatric urology is a subspeciality of urology, with close links to paediatric surgery. This review concludes that a holistic life-long approach to management in highly specialised treatment centres is essential for many of the rare congenital conditions - in Denmark, paediatric urology is centralised to two institutions: Rigshospitalet in Copenhagen and Aarhus University Hospital in Aarhus. Other than performing basic urology in paediatric patients, both centres specialise in complex and rare urological conditions and thus have been accredited by the European Reference Network on rare diseases through the eUrogen collaboration. Patient populations have covered span from prenatal to childhood, transition and for some anomalies, even into adulthood.

The prognostic value of testicular microlithiasis as an incidental finding for the risk of testicular malignancy in children and the adult population: A systematic review. On behalf of the EAU pediatric urology guidelines panel

INTRODUCTION

The exact correlation of testicular microlithiasis (TM) with benign and malignant conditions remains unknown, especially in the paediatric population. The potential association of TM with testicular malignancy in adulthood has led to controversy regarding management and follow-up.

OBJECTIVE

To determine the prognostic importance of TM in children in correlation to the risk of testicular malignancy or infertility and compare the differences between the paediatric and adult population.

STUDY DESIGN

We performed a literature review of the Medline, Embase and Cochrane controlled trials databases until November 2020 according to the Preferred Reporting Items of Systematic Reviews and Meta-Analyses (PRISMA) Statement. Twenty-six publications were included in the analysis.

RESULTS

During the follow-up of 595 children with TM only one patient with TM developed a testicular malignancy during puberty. In the other 594 no testicular malignancy was found, even in the presence of risk factors. In the adult population, an increased risk for testicular malignancy in the presence of TM was found in patients with history of cryptorchidism (6% vs 0%), testicular malignancy (22% vs 2%) or sub/infertility (11-23% vs 1.7%) compared to TM-free. The difference between paediatric and adult population might be explained by the short duration of follow-up, varying between six months and three years. With an average age at inclusion of 10 years and testicular malignancies are expected to develop from puberty on, testicular malignancies might not yet have developed.

CONCLUSION

TM is a common incidental finding that does not seem to be associated with testicular malignancy during childhood, but in the presence of risk factors is associated with testicular malignancy in the adult population. Routine monthly self-examination of the testes is recommended in children with contributing risk factors from puberty onwards. When TM is still present during transition to adulthood a more intensive follow-up could be considered.

Ileal Neoappendicostomy in the Treatment of Fecal Incontinence in Children

INTRODUCTION

 An antegrade colonic enema (ACE) via an appendicostomy has been shown to be effective in the management of functional bowel problems. In cases with a missing appendix, a neoappendicostomy may be considered.

MATERIALS AND METHODS

 A retrospective review of clinical outcomes in children who underwent ileal neoappendicostomy for ACE. Medical records were reviewed for data on demography, intra- and postoperative complications. A follow-up questionnaire on stoma problems, ACE-related problems, bowel function, patient satisfaction, well-being, and effect on daily activities was performed.

RESULTS

 Ten patients were included at an average age of 10.6 years at surgery. In half of the patients, minor postoperative complications (Clavien-Dindo grade 2 or less) were found. Nine patients answered the questionnaire with a mean follow-up of 57 months. Despite complaints of stomal leakage, difficulties with catheterization, and pain during irrigation, they reported a high grade of satisfaction, improvements in well-being, and bowel function and the achievement of continence.

CONCLUSION

 Ileal neoappendicostomy may be an alternative to ACE in children with severe and medically intractable constipation and or/and fecal incontinence where the appendix is missing or not available.

A case of penile duplication with neonatal teratoma and bladder neck incompetence

An 8-year-old boy presented with a duplicated penis and urinary incontinence. He had a history of a perineal teratoma which was removed during his first week of life. Examination revealed a large prepuce, 90-degree counter clockwise rotation of the penis, an orthotopic megalomeatus and an additional smaller glans dorsally. Cystourethroscopy and artificial erection showed a wide-open bladder neck and deviation of the penis(es) to the right. There were two cavernosae in the orthotopic penis and one in the duplicated rudimentary penis. The patient was subjected to Young-Dees bladder neck reconstruction and two years later, excision of the rudimentary penis. A satisfactory cosmetic result was achieved, the patient is voiding normally, and urinary incontinence improved. Penile duplication is a rare anomaly, which presents differently in each patient. Therefore, treatment should be individualized, and the goal of surgery being to achieve as a near normal cosmetic and functional result as possible.

Update of the EAU/ESPU guidelines on urinary tract infections in children

INTRODUCTION/BACKGROUND

Urinary tract infections (UTIs) are common in children and require appropriate diagnostic evaluation, management and follow-up.

OBJECTIVE

To provide a summary of the updated European Association of Urology (EAU) guidelines on Pediatric Urology, which were first published in 2015 in European Urology.

STUDY DESIGN

A structured literature review was performed of new publications between 2015 and 2020 for UTIs in children. The guideline was updated accordingly with relevant new literature.

RESULTS

The occurrence of a UTI can be the first indication of anatomical abnormalities in the urinary tract, especially in patients with a febrile UTI. The basic diagnostic evaluation should include sufficient investigations to exclude urinary tract abnormalities, but should also be as minimally invasive as possible. In recent years, more risk factors have been identified to predict the presence of these anatomical anomalies, such as a non-E. Coli infection, high grade fever and ultrasound abnormalities. When these risk factors are factored into the diagnostic work-up, some invasive investigations can be omitted in a larger group of children. In addition to the treatment of active UTIs, it is also essential to prevent recurrent UTIs and consequent renal scarring. With the increase of antimicrobial resistance good antibiotic stewardship is needed. In addition, alternative preventative measures such as dietary supplements, bladder and bowel management and antibiotic prophylaxis could decrease the incidence of recurrent UTI.

CONCLUSION

This paper is a summary of the updated 2021 EAU guidelines on Pediatric Urology. It provides practical considerations and flowcharts for the management and diagnostic evaluation of UTIs in children.

[Foreskin transplantation between monozygotic twins discordant for hypospadias]

This is a case report of monozygotic twins discordant for hypospadias, where the afflicted twin, a 33-year-old male, needed extensive redo urethral reconstruction. A two-stage reconstruction was planned by using the twin brother's prepuce. The scarred urethra was replaced by the isograft, and one year later the second stage was completed. At five-year follow-up, there was good cosmesis, and the index patient reported excellent voiding and no fistulae or stenosis. Despite its rarity, foreskin transplantation between discordant monozygotic twins is possible and offers a unique and durable management opportunity.

EAU/ESPU guidelines on the management of neurogenic bladder in children and adolescent part II operative management

BACKGROUND

Treatment in children and adolescents with a neurogenic bladder is primarily conservative with the goal of preserving the upper urinary tract combined with a good reservoir function of the bladder. However, sometimes-even in childhood-conservative management does not prevent the development of a low-compliant bladder or overactive detrusor.

MATERIAL & METHODS

After a systematic literature review covering the period 2000-2017, the ESPU/EUAU guideline for neurogenic bladder underwent an update.

RESULTS

In these patients, surgical interventions such as botulinum toxin A injections into the detrusor muscle, bladder augmentation, and even urinary diversion may become necessary to preserve the function of the upper (and lower) urinary tracts. The creation of a continent catheterizable channel should be offered to patients with difficulties performing transurethral clean intermittent catheterization. However, a revision rate of up to 50% needs to be considered. With increasing age continence of urine and stool becomes progressively more important. In patients with persistent weak bladder outlets, complete continence can be achieved only by surgical interventions creating a higher resistance/obstruction at the level of the bladder outlet with a success rate of up to 80%. In some patients, bladder neck closure and the creation of a continent catheterizable stoma is an option.

CONCLUSION

In all these patients close follow-up is mandatory to detect surgical complications and metabolic consequences early.

EAU/ESPU guidelines on the management of neurogenic bladder in children and adolescent part I diagnostics and conservative treatment

BACKGROUND

In childhood, the most common reason for a neurogenic bladder is related to spinal dysraphism, mostly myelodysplasia.

AIMS

Herein, we present the EAU/ESPU guidelines in respect to the diagnostics, timetable for investigations and conservative management including clean intermittent catheterization (CIC).

MATERIAL AND METHODS

After a systematic literature review covering the period 2000 to 2017, the ESPU/EUAU guideline for neurogenic bladder underwent an update.

RESULTS

The EAU/ESPU guideline panel advocates a proactive approach. In newborns with spina bifida, CIC should be started as soon as possible after birth. In those with intrauterine closure of the defect, urodynamic studies are recommended be performed before the patient leaves the hospital. In those with closure after birth urodynamics should be done within the next 3 months. Anticholinergic medication (oxybutynin is the only well-investigated drug in this age group-dosage 0.2-0.4 mg/kg weight per day) should be applied, if the urodynamic study confirmed detrusor overactivity. Close follow-up including ultrasound, bladder diary, urinalysis, and urodynamics are necessary within the first 6 years and after that the time intervals can be prolonged, depending on the individual risk and clinical course. In all other children with the suspicion of a neurogenic bladder due to various reasons as tethered cord, inflammation, tumors, trauma, or other reasons as well as those with anorectal malformations, urodynamics-preferable video-urodynamics, should be carried out as soon as there is a suspicion of a neurogenic bladder and conservative treatment should be started soon after confirmation of the diagnosis of neurogenic bladder. With conservative treatment the upper urinary tract is preserved in up to 90%, urinary tract infections are common, but not severe, complications of CIC are quite rare and continence can be achieved at adolescence in up to 80% without further treatment.

DISCUSSION AND CONCLUSIONS

The transition into adulthood is a complicated time for both patients, their caregivers and doctors, as the patient wants to become independent from caregivers and treatment compliance is reduced. Also, transition to adult clinics for patients with neurogenic bladders is often not well-established.

Syringocele: a retrospective study and review of the literature

Background: A syringocele is a cystic dilation of the ducts from the bulbourethral glands located in the bulbous part of the male urethra. It is a rare condition primarily reported in children and young adults. The objective was to evaluate the diagnostic pattern and management strategy in patients of all ages diagnosed with syringocele.Methods: A retrospective review of patients with syringocele in the period 2004-2018 was performed. Age at diagnosis, primary symptoms, the diagnostic modalities used, treatments and effects were registered.Results: In the period, 19 patients with syringoceles were identified, eight children and 11 adults. The majority of the patients presented with obstructive voiding symptoms. All patients underwent cystourethroscopy. Supplementary diagnostics as voiding cystourethrography, retrograde urethrography, uroflowmetry, magnetic resonance imaging or transrectal ultrasonography were used inconsistently. Sixteen of the patients underwent marsupialization, one child underwent open excision and two patients were managed conservatively. Three of the children were re-operated on with endoscopic marsupialization. One of the adult patients did not respond to marsupialization and was treated with and vesico-appendico-cutaneostomy.Discussion: A review of the case reports published in the period 1996-2018 was performed and compared to these results. This review found 77 cases, 50 children and 27 adults. The reported symptoms, diagnostics and treatments were in line with the findings of this study.Conclusions: Based on these findings and the literature it is recommended that syringoceles should be diagnosed by cystourethroscopy and urethrography. Patients with symptomatic syringoceles should be offered treatment. First line treatment is endoscopic marsupialization.

Pelvic floor electrophysiology in spinal cord injury

OBJECTIVE

The study aimed to investigate sacral peripheral nerve function and continuity of pudendal nerve in patients with chronic spinal cord injury (SCI) using pelvic floor electrophysiological tests.

METHODS

Twelve patients with low cervical or thoracic SCI were prospectively included. Quantitative external anal sphincter (EAS) muscle electromyography (EMG), pudendal nerve terminal motor latency (PNTML) testing, bulbocavernosus reflex (BCR) testing and pudendal short-latency somatosensory-evoked potential (SEP) measurement were performed.

RESULTS

In EAS muscle EMG, two patients had abnormal increased spontaneous activity and seven prolonged motor unit potential duration. PNTML was normal in 10 patients. BCR was present with normal latency in 11 patients and with prolonged latency in one. The second component of BCR could be recorded in four patients. SEPs showed absent cortical responses in 11 patients and normal latency in one.

CONCLUSIONS

Pudendal nerve and sacral lower motor neuron involvement are significantly associated with chronic SCI, most prominently in EAS muscle EMG. The frequent finding of normal PNTML latencies supports earlier concerns on the utility of this test; however, BCR and pudendal SEPs may have clinical relevance.

SIGNIFICANCE

As intact peripheral nerves including pudendal nerve are essential for efficient supportive therapies, pelvic floor electrophysiological testing prior to these interventions is highly recommended.

International Children's Continence Society's recommendations for initial diagnostic evaluation and follow-up in congenital neuropathic bladder and bowel dysfunction in children

PURPOSE

The objective of this ICCS standardization document is to report the initial diagnostic evaluation and subsequent work-up of children with neuropathic bladder dysfunction.

MATERIALS AND METHODS

Due to a paucity of level I or level II, "levels of evidence" publications, these recommendations are actually a compilation of best practices because they seem to be effective and reliable, although not with any control.

RESULTS

Throughout the document, the emphasis is on promoting early, comprehensive evaluation of lower urinary tract function that is thorough but with a minimum of unnecessary testing. This includes what tests to order, when to order them and what to do with the results. Some of the recommendations may not be practical in various worldwide locations but the suggested testing should be considered the ideal approach to completely diagnosing and then promulgating treatments based on the full knowledge of the condition and its effect on urinary tract function. Once the findings are delineated, those lower urinary tract patterns of dysfunction that put the kidneys at risk for deterioration, that are barriers to attaining eventual continence, and that have long-term consequence to the lower urinary track can be obviated by specific management recommendations. The indications and timing of investigations to achieve these objectives are clearly defined in each diagnostic category and during follow-up.

RECOMMENDATIONS

This document should be used as a basis for appropriate evaluation and timely surveillance of the various neuro-urologic conditions that affect children.

[Surgical reinnervation with nerve anastomosis technique for neurogenic bladder and bowel dysfunction]

Neurogenic bladder and bowel dysfunction are among the major problems faced by patients with spinal cord injury and myelomeningocele. New treatment modalities enforcing more natural patient control of voiding and defecation are therefore appealing. We present a historical review of crossover surgery as treatment for such deficiencies and, further, describe the principles as well as the documentation for modern surgical intervention in the form of a somato-autonomic reflex arch.

Urinary flow patterns in infants with distal hypospadias

OBJECTIVE

To investigate preoperative urinary flow patterns in hypospadic infants and compare them to those from normal infant boys.

PATIENTS AND METHODS

Twenty-one boys (median age 14.0, range 12.8-21.6 months) referred for distal hypospadias surgery were compared to 19 healthy boys (median age 12.0, 9.2-19.8 months). In both groups a 14-mm transit-time ultrasound flow probe mounted around the base of the penis continuously registered uroflow.

RESULTS

Median maximum flow rate (Q(max)) was significantly lower in hypospadics (2.4 vs 4.4 ml/s, P < 0.01) while there was no difference in the voided volume per micturition (19.0 vs 21.0 ml, P 0.33). Flow curve pattern analysis revealed plateau-shaped curves in 31% of hypospadics compared to none in normal infant boys. Interestingly, dyscoordinated flow curves (interrupted, staccato, spike-dome) were less common in the hypospadics (36% vs 64%, P < 0.01). Meatal size did not correlate to Q(max) (rho = 0.26, P = 0.26).

CONCLUSIONS

Infants with hypospadias void with a lower Q(max) and a lesser degree of dyscoordination as compared to normal infant boys. It can be speculated that decreased urethral compliance may contribute to the lower Q(max) and may act as a silencer for dyscoordination.

Endoluminal pelvic perfusion with norepinephrine causes only minor systemic effects and diminishes the increase in pelvic pressure caused by perfusion

OBJECTIVE

To evaluate the effect of endoluminal norepinephrine (NE) on transport pressures of the normal upper urinary tract of the pig and on plasma levels of NE in relation to possible systemic effects.

MATERIAL AND METHODS

Six anaesthetized pigs weighing approximately 39 kg were studied. Transparenchymally, two 6-F catheters were introduced into the renal pelvis bilaterally to measure pressure and perfusion. Ultrasonic flow probes recorded renal arterial blood flow, and a transurethral 10-F catheter drained the bladder and monitored diuresis. In all six animals, the bilateral pelvic pressure response was examined at increasing perfusion rates (2, 4, 6, 8, 10 and 15 ml/min) and with increasing doses of NE (0, 5, 50 and 100 microg/ml). Arterial blood samples were analysed for NE, epinephrine and blood glucose. The systemic blood pressure, heart rate and electrocardiogram were registered.

RESULTS

At all the investigated concentrations, endoluminal NE significantly diminished the increase in pelvic pressure caused by pelvic perfusion at all flow rates. At the lowest concentration of NE, no significant increase in the plasma level of NE was observed and the blood pressure did not increase. During perfusion with 50 and 100 microg/ml NE, plasma levels of NE increased significantly from 487+/-398 to 1798+/-910 and 2961+/-2093 pg/ml, respectively. This was accompanied by significant rises in mean systolic blood pressure from a baseline value of 95+/-10 mmHg to 111+/-20 and 118+/-23 mmHg, respectively. Heart rate, renal arterial blood flow and plasma levels of epinephrine and glucose did not change.

CONCLUSIONS

Endoluminal NE diminished the increase in pelvic pressure caused by pelvic perfusion even at concentrations too low to cause significant changes in NE plasma levels or systemic effects. Very high NE concentrations in the perfusion fluid caused increased plasma levels and a modest but significant increase in blood pressure. Administration of endoluminal NE may be useful in upper urinary tract stone treatment and endoscopy.

Regional changes in renal cortical glucose, lactate and urea during acute unilateral ureteral obstruction

OBJECTIVE

Acute unilateral ureteral obstruction (UUO) leads to changes in kidney function and metabolism. Microdialysis offers the possibility of topical analysis of changes in kidney metabolism. We applied microdialysis to the porcine kidney and evaluated its impact on gross kidney function. Furthermore, we investigated regional variations in renal interstitial fluid (RIF) glucose, lactate and urea during acute UUO.

MATERIAL AND METHODS

Eight anesthetized pigs were used. Microdialysis probes were inserted in the upper, middle and lower thirds of the left renal cortex and perfused with Ringer's chloride at a rate of 0.3 microl/min. Dialysates were fractionated for 30-min periods. Bilateral intrapelvic pressure, urinary output, urinary osmolality, the excretion fractions of sodium and potassium, renal blood flow and the glomerular filtration rate were measured. Subsequently, left-sided graded ureteral obstruction was initiated, using the kidney's own urine production as a counter-pressure.

RESULTS

The application of three microdialysis probes did not have any impact on kidney function. Ureteral obstruction decreased RIF glucose in the upper and lower thirds of the kidney, but not in the middle third. RIF lactate did not change. Interstitial urea increased in all regions of the kidney, but most markedly in the upper and lower poles.

CONCLUSIONS

Microdialysis is of potential value for assessing the renal interstitial milieu under different pathophysiological conditions. Ureteral obstruction resulted in regional differences in cortical metabolites, predominantly affecting the upper and lower poles.

[Lower limb compartment syndrome following laparoscopic sigmoid resection in the lithotomy position]

Lower limb compartment syndrome subsequent to surgery in the lithotomy position is a rare but devastating complication, termed well leg compartment syndrome (WLCS). We report a case of WLCS after a 290 minute long laparoscopic sigmoid resection commenced in the Lloyd-Davies position. 27 hours after surgery, four-compartment fasciotomy was performed confirming the diagnosis of compartment syndrome. The patient was discharged with a limp, awaiting further follow-up. Surgeons must be able to diagnose WLCS as delayed treatment may result in severe neuromuscular dysfunction.

[Lower limb compartment syndrome subsequent to surgery in the lithotomy position]

Lower limb compartment syndrome after prolonged surgery in the lithotomy position is a rare but devastating complication which is termed well leg compartment syndrome (WLCS). The pathogenesis comprises increase in intracompartmental pressure and hypoperfusion, resulting in ischemia and necrosis. By reviewing the PubMed database we found 38 case reports with a total of 58 patients who developed WLCS. Every surgeon should know WLCS as early diagnosis and treatment is essential to avoid severe permanent disability.

Pediatric robot assisted retroperitoneoscopic pyeloplasty: a 5-year experience

PURPOSE

We report our 5-year experience with retroperitoneoscopic robot assisted pyeloplasty for the treatment of ureteropelvic junction obstruction in children using the da Vinci Surgical System.

MATERIALS AND METHODS

A total of 65 children (median age 7.9 years, range 1.7 to 17.1) underwent 67 robot assisted retroperitoneoscopic pyeloplasties with the da Vinci Surgical System between 2002 and 2006. Operative data were sampled prospectively, while outcome data were collected from chart review. Retroperitoneal access was modified from standard retroperitoneoscopic access due to the limits of the camera arm movement.

RESULTS

Median operative time was 143 minutes (range 93 to 300). Complications occurred in 12 of the 67 procedures (17.9%), with urinary tract infection observed in 2 cases, transient hematuria in 2, displaced Double-J catheter in 3 and postoperative temporary nephrostomy in 4. One case was converted to open surgery due to lack of space and limits in the movement of the camera arm. Four patients (6%) underwent repeat surgery due to a kinking ureter (2 patients), an overlooked aberrant vessel (1) and decreasing differential function on renography necessitating balloon dilation (1). In all other cases followup was uneventful.

CONCLUSIONS

Robot assisted retroperitoneoscopic pyeloplasty gives more direct access to the ureteropelvic junction, allowing shorter operative times with results and complication rates comparable to transperitoneal robot assisted pyeloplasty, and laparoscopic and open procedures in children.

Glomerular and tubular function during AT1 receptor blockade in pigs with neonatal induced partial ureteropelvic obstruction

Previously, we showed that neonatal induced chronic partial unilateral ureteral obstruction (PUUO) of the multipapillary pig kidney decreased glomerular filtration rate (GFR) of the obstructed kidney. We hypothesized that ANG II and nitric oxide (NO) are important for the changes in renal function and in the present study we examined the effects of chronic AT1 receptor blockade using CV-11974 (0.12 mg/h candesartan from age 23 to 30 days) on kidney function development after PUUO was induced in 2-day-old piglets. Moreover, the effect of superimposed acute NO inhibition using NG-nitro-l-arginine methyl ester (l-NAME; 15 mg/kg) was examined to identify if this has diagnostic potential. PUUO significantly increased GFR in the nonobstructed contralateral kidney independent of candesartan. In candesartan-treated piglets, the l-NAME-induced GFR reduction seen in normal and nonobstructed kidneys was absent in the partial obstructed kidneys. Urine output and fractional excretion of water were increased from the partial obstructed kidneys. Consistent with this immunohistochemical analyses showed a reduced aquaporin-2 labeling in the collecting duct principal cells. Moreover, renal sodium handling was compromised by PUUO evidenced by an increased fractional excretion of sodium which was enhanced by candesartan treatment. In conclusion, our findings suggest that the counterbalance between AT1 receptor-mediated vasoconstriction and NO-mediated vasodilatation which maintain GFR in normal young porcine kidneys is changed by neonatal induced chronic PUUO. This may have diagnostic potential in children with suspected congenital obstruction. Our results also demonstrate compromised tubular functions in response to chronic PUUO despite preservation of glomerular function.

The role of renal resistive index measures in the diagnostic work up of congenital hydronephrosis

OBJECTIVE

To evaluate the role of renal resistive index (RI) measures in the diagnostic work up of congenital hydronephrosis.

METHODS AND MATERIALS

Seventeen neonatal pigs were randomized to either left-sided partial unilateral ureteral obstruction (n=12) or sham operation (n=5) at 2 weeks of age. Serial investigations including B-mode ultrasound, RI measures and combined clearance/renographic evaluations were performed at 4, 12 and 24 weeks of age under light sedation. Results were analysed statistically, and receiver operating characteristic (ROC) curves were generated in order to evaluate the diagnostic efficacy of RI.

RESULTS

In all, 15 animals completed the study protocol. In the obstructed group, hydronephrosis and significant compromise of renal function developed on the subject side, whereas sham-operated pigs had stable renal morphology and function throughout the study. There were however no significant differences in RI or DeltaRI between the two groups at any age, or between right and left RIs in the obstructed group at any point. RI and DeltaRI had no prognostic or diagnostic value as judged by ROC curve analysis.

CONCLUSIONS

RI and DeltaRI were not affected by partial unilateral ureteral obstruction induced in the immature neonatal porcine kidney. The results of this study do not support the clinical use of Doppler ultrasound studies in the diagnostic work up of congenital hydronephrosis.

THE EFFECT OF ALARM TREATMENT ON THE FUNCTIONAL BLADDER CAPACITY IN CHILDREN WITH MONOSYMPTOMATIC NOCTURNAL ENURESIS

PURPOSE

We studied the characteristics of a group of monosymptomatic nocturnal enuretics successfully treated with the alarm system, with special reference to changes in functional bladder capacity.

MATERIALS AND METHODS

The diaries of 7 girls and 19 boys 7 to 13 years old with severe nocturnal enuresis, small daytime bladder capacity (70% or less of expected capacity for age) and poor or absent response to desmopressin were analyzed. Patients were treated with an alarm until complete dryness was achieved for 21 consecutive nights before ending therapy. Immediately after the treatment they recorded a 1-week followup diary of voiding and fluid intake.

RESULTS

Mean duration of the alarm treatment was 82 days, and there was no change in nocturnal or 24-hour diuresis from baseline to followup. Nocturia developed during the alarm treatment in 48% of the children. The nocturnal diuresis on nocturia nights was significantly higher than on nights without nocturia. Daytime functional bladder capacity increased significantly in children with and without nocturia.

CONCLUSIONS

Treatment with an alarm system increases daytime functional bladder capacity significantly in children with and without nocturia. A higher nocturnal urine production on nocturia nights explains why some children have nocturia and others do not.

THE OUTCOME OF DETRUSOR MYOTOMY IN CHILDREN WITH NEUROGENIC BLADDER DYSFUNCTION

PURPOSE

We evaluate the outcome of detrusor myotomy for neurogenic bladder dysfunction (NBD) in children.

MATERIALS AND METHODS

A retrospective analysis was performed of data compiled from medical and urodynamic records of children younger than 16 years with NBD who had undergone detrusor myotomy from 1992 to 2000 at our department.

RESULTS

Surgery was performed in 14 children with a mean age +/- SD of 6.7 +/- 4.3 years (range 0.9 to 14.2) and mean followup of 5.9 +/- 1.7 years. All patients were diagnosed with NBD, which was the result of myelomeningocele in 9, sacral agenesis in 2, lumbosacral lipoma in 1, multiple vertebral anomalies in 1 and spinal neuroblastoma in 1. Main indications for surgery included urinary incontinence in 11 cases and high pressure/low capacity bladders with vesicoureteral reflux and impending renal damage in 8. No major postoperative complications were recorded. Although mean maximal cystometric bladder capacity was unchanged 1 month postoperatively (89.7 +/- 70.6 ml) compared to preoperatively (92.5 +/- 75.1 ml, p = 0.87), significant increments of 216%, 237% and 292% were measurable at 3 months, 1 year and 5 years, respectively. Ultimately most of the patients approached age specific capacities. Complete continence on clean intermittent catheterization was achieved by 8 of 11 patients and improved markedly in 1. Reflux was alleviated in 6 cases and improved in 1. Kidney function developed normally in all but 1 patient with persistent reflux.

CONCLUSIONS

When feasible, detrusor myotomy offers a safe and effective alternative for the management of pharmacologically intractable NBD in children.

Norepinephrine inhibits the pelvic pressure increase in response to flow perfusion

PURPOSE

We evaluated the effects of norepinephrine on transport pressures in the normal upper urinary tract of the pig during increasing perfusion rates.

MATERIALS AND METHODS

Anesthetized Danish landrace Yorkshire pigs weighing 38 to 40 kg were studied. Transparenchymally 2, 6Fr catheters were introduced into the left renal pelvis for pressure measurements and perfusion, respectively. An ultrasonic flow probe was inserted around the left renal artery to record blood flow. A 10Fr catheter was placed transurethrally for bladder drainage and the bladder was maintained empty during the entire study. In the 5 group 1 pigs the pelvic pressure increase was examined at increasing perfusion rates of the renal pelvis (2, 4, 6, 8, 10 and 15 ml per minute) in response to endoluminal administration of increasing concentrations of norepinephrine (0, 5, 50 and 100 microg/ml) in saline. In the 5 group 2 pigs the pressure flow study was also done 4 times per animal using isotonic saline.

RESULTS

Endoluminal norepinephrine had a dose dependent effect on the pressure flow relationship. Perfusion with 5 and 50 microg/ml norepinephrine caused a delayed increase and a decrease in pelvic pressure in response to increasing flow rates, whereas perfusion with 100 microg/ml norepinephrine significantly inhibited and almost eliminated the pressure increase at all perfusion rates compared with saline perfusion. Importantly there were no changes in blood pressure, the heart rate or renal arterial blood flow. In group 2 perfusion with isotonic saline resulted in the same pressure response to increasing flow rates each time.

CONCLUSIONS

Endoluminal administration of norepinephrine caused a dose dependent inhibition on the pressure phases of the pressure flow relationship of the upper urinary tract in pigs. No systemic changes were observed. These observations may provide a useful adjuvant treatment strategy for upper urinary tract stone treatment and endoscopy.

Demographics of enuresis patients attending a referral centre

OBJECTIVE

To study and compare the demography of enuretic children 7-16 years old attending a tertiary referral centre for childhood urinary incontinence, with that of normal children and what is generally known about enuretics from population-based studies.

METHODS AND MATERIALS

This was a retrospective analysis of data compiled from 298 enuretic patients referred to The Centre of Child Incontinence, Aarhus University Hospital, Skejby, Denmark, and 53 healthy controls. Data was obtained by conducting standardised questionnaire interviews. Patients were stratified according to accompanying symptoms and severity of enuresis. Statistical analysis of the results was then performed.

RESULTS

Two hundred and ninety-three patients had sufficient data registered to allow reliable analysis. Male-female ratio was 2.2:1. Primary and secondary enuresis was found in 87.4% and 11.6% of the patients respectively. Enuresis was associated with a reported history of bronchial asthma (p < 0.05), verified allergy (p < 0.05) and a positive family history of the same disorder (p < 0.01). No association with psycho-developmental factors was evident. Approximately 98% of the patients had undergone some form of therapy at presentation. 74.1% of the patients had pure monosymptomatic enuresis, 16.4% had day and night time incontinence, while the remaining 9.6% had nocturnal incontinence combined with other lower urinary tract symptoms other than daytime wetting.

CONCLUSIONS

The demography of our patient population was, with a few exceptions, within the confines of what has previously been reported. Our results also reaffirmed the heterogeneity of enuretic patients.

Resistive index: an experimental study of acute complete unilateral ureteral obstruction

RATIONALE AND OBJECTIVES

To study the effects of acute complete unilateral ureteral obstruction (UUO) and release on porcine renal resistive index (RI).

METHODS

Under general anesthesia, UUO was induced in six pigs. RI was measured bilaterally at predetermined intervals for 4 hours of UUO and 1 hour of release. Additionally, measures of renal blood flow (RBF), glomerular filtration rate (GFR), arterial blood pressure, renal vascular resistance (RVR), and ipsilateral renal intrapelvic pressure (IPP) were obtained.

RESULTS

UUO and resultant progressive IPP increase caused prompt and significant ipsilateral RI elevation, and contralateral RI decrease. Concomitantly, ipsilateral RVR increased significantly while RBF and GFR declined, both significantly. Release of obstruction saw an almost immediate normalization of ipsilateral RI, RVR and RBF while ipsilateral GFR assumed 80% of baseline value 15 minutes postobstruction. Throughout the experiment, ipsilateral RI correlated significantly with changes in IPP, GFR, RBF, and RVR with correlation coefficients of 0.844, -0.851, -0.898, and 0.836 respectively ( < 0.001).

CONCLUSIONS

UUO causes a divergent RI response that is instantly reversed upon release. IPP seems to be the principal effector of these changes in the early phases of UUO.

The relationship between desmopressin treatment and voiding pattern in children

OBJECTIVE

To collect data on voiding patterns at baseline (no treatment) and during short-term desmopressin treatment, with special reference to the functional and the mean bladder capacity.

PATIENTS AND METHODS

The study included 120 children (aged 6-16 years) with monosymptomatic nocturnal enuresis. While at home they recorded their fluid intake and diuresis in two separate periods, i.e. 2 weeks as a baseline registration and another 2 weeks during desmopressin titration. On four study days the children recorded the time and volume of all voids and of fluid intake. From the diaries their functional and mean bladder capacities, 24-h diuresis and day/night ratio of diuresis were determined.

RESULTS

The mean 24-h diuresis was significantly lower during short-term desmopressin treatment. In most of the enuretics the mean day/night ratio increased on desmopressin treatment. The mean functional and mean bladder capacities were unaffected by desmopressin. Those not responding had bladder capacities of approximately 100 mL less than full responders. Regardless of response, practically all the enuretics in the study had a smaller functional bladder capacity than expected for their age. Among responders the morning void was significantly larger than the following voids during the day, and among non-responders the fourth void was significantly larger than the previous voids in the day. Desmopressin treatment did not influence these volumes significantly.

CONCLUSIONS

Short-term desmopressin treatment does not affect functional and mean bladder capacity; 24-h urine production was reduced significantly (P<0.01) during desmopressin treatment.

Resistive index: an experimental study of the effects of diuretic stimulation in the unobstructed porcine kidney

OBJECTIVE

To study the effects of diuretic stimulation with frusemide and mannitol on the renal resistive index (RI) of the undilated unobstructed porcine kidney.

MATERIALS AND METHODS

Experiments were carried out on 14 pigs divided into two equal groups (A and B), under general anaesthesia. In all pigs both ureters were catheterized, thereby allowing urine output to be measured on each side separately, and an indwelling catheter in a femoral artery used to continuously measure the systemic blood pressure. Furthermore, in five pigs from each group, right renal blood flow was measured by ultrasonic flow probes placed around the renal arteries. The right kidney RI was measured at baseline and at 5-min intervals after frusemide (group A) and mannitol (group B) stimulation, for 75 min.

RESULTS

Frusemide caused significant increases in diuresis (P < 0.001) and renal blood flow (P = 0.009). This was accompanied by a significant decrease in mean arterial pressure (P < 0.001). The RI was unaffected (P = 0.706), with mean values in group A of 0.58-0.65. Mannitol also caused a significant increase in diuresis (P < 0.001) and a subtle but significant decrease in mean arterial pressure (P < 0.001). However, renal blood flow was unaffected by the diuretic (P = 0.820); the mean RI values were unaffected, at 0.61-0.66 (P = 0.375).

CONCLUSIONS

These results show that diuretic stimulation with frusemide or mannitol does not affect the RI of the unobstructed undilated porcine kidney, despite significant changes in diuresis, renal blood flow and mean arterial pressure.

Short- and long-term repeatability of intrarenal resistive index in the pig

RATIONALE AND OBJECTIVES

To evaluate the short- and long-term repeatability (intraobserver variation) of the renal resistive index (RI) in a pig model.

METHODS

Under standardized ambient conditions, short- and long-term repeatabilities were assessed by measuring the RI three consecutive times at 30-minute intervals in 14 pigs and twice 4 weeks apart in 6 pigs, respectively. Repeatability was judged according to predefined criteria, which included calculation of coefficients of variation (CVs) and repeatability coefficients combined with visual assessment and estimation of bias.

RESULTS

Short-term repeatability was acceptable, having an average CV of 4.9% +/- 2.9% and of 6.1% +/- 4.7% in two comparisons, findings that were reiterated in the visual assessment. Long-term results were, however, less consistent, having an average CV of 8.1% +/- 6.1% and prominent scatter on the visual assessment graphs.

CONCLUSIONS

In this study, RI measurements showed an acceptable short-term repeatability, whereas long-term results were less consistent. The components of error contributing to the modest long-term repeatability need to be investigated in studies of larger populations.

The intrarenal resistive index as a pathophysiological marker of obstructive uropathy

PURPOSE

The intrarenal resistive index is a physiological parameter that indirectly reflects the degree of resistance in the intrarenal vasculature. Resistive index measurements have been advocated for the diagnostic evaluation of several renal pathologies, including obstructive uropathy. However, despite extensive research in this field during the last decade clear guidelines on the use of resistive index measurements for discriminating obstructive from nonobstructive dilatation of the upper urinary tract remain elusive. Therefore, we reviewed the literature to clarify the proper role of resistive index measurements in the context of obstructive uropathy.

MATERIALS AND METHODS

We reviewed the recent literature on the use of resistive index measurements for the diagnostic evaluation of obstructive uropathy.

RESULTS

Despite a continuously growing body of literature the resistive index has yet to be recognized as a dependable parameter when it comes to resolving the long-standing dilemma of the dilated upper urinary tract. While proponents have observed that this method has sensitivity and specificity that supersede those of conventional methods, opponents have reported that the resistive index is an unreliable parameter that is prone to systemic and local influences.

CONCLUSIONS

Resistive index measurements are still in a developmental phase. Additional studies are needed before this technique may be used reliably for the diagnosis of obstructive uropathy.

Resistive index: an experimental study of the normal range in the pig

OBJECTIVES

To study the normal range and distribution of the resistive index (RI) and the resistive index ratio (RIR) in the non-obstructed non-dilated porcine kidney, and to assess the reliability of the threshold values RI 0.70 and RIR 1.10 as prognosticators of true obstruction in the upper urinary tracts.

METHODS AND MATERIALS

Twenty female pigs of Danish land race breed were studied under general anaesthesia. Blood pressure and urine output was monitored throughout the experiment. Doppler evaluations were obtained from an interlobar artery in the lower half of each kidney, and the RI was calculated as the average of 3 x 3 cycles for each side independently. Statistical analysis of the obtained results was performed.

RESULTS

Forty renal units were studied. The RI values ranged from 0.48-0.85 (mean 0.63). Nine renal units (22.5%) had RI values > or = 0.70. RIR values ranged from 1.00-1.38 (mean 1.07). Three RIR values (15%) were above 1.10. There was no statistically significant relationship between RI and laterality (p = 0.25), and no overall significant relationship between RI and mean arterial blood pressure (r2 = 0.21) or urine output (r2 = 0.004).

CONCLUSIONS

This study shows a wide distribution of the RI normal values in the pig model, and our results do not support the normal ranges for RI and RIR, or the cut-off values used in clinical practice.