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Hsi-Yang Wu
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ABSTRACT: Achievement of urinary continence is an important developmental step that most children attain with the assistance of their parents and caregivers. Debate continues as to the best time to toilet train; in some Asian and African cultures children are trained as infants, while training at age 2-3 years is more typical in Western cultures. Infant voiding is not merely a spinal reflex, as the sensation of bladder filling is relayed to the brain. However, the ability of the brain to inhibit bladder contractions, and to achieve coordinated bladder contraction with sphincter relaxation, matures over time. While there is a concern that later toilet training may be responsible for an increase in urinary incontinence in children, no controlled studies on early versus late toilet training exist to evaluate this hypothesis. A number of medical conditions such as spina bifida, posterior urethral valves, cerebral palsy and autism can cause incontinence and difficulties in toilet training. The decision to start toilet training a child should take into account both the parents' expectation of how independent the child will be in terms of toileting, and the child's developmental readiness, so that a realistic time course for toilet training can be implemented.
Nature Reviews Urology 07/2010; 7(7):371-7. · 4.41 Impact Factor
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ABSTRACT: Patients with nocturnal enuresis may have small functional bladder capacity or altered bladder fullness sensation. We determined whether reducing bladder volume would affect the central inhibition of voiding that is normally present between birth and 2 weeks of life in neonatal rats.
One and 3-week-old Sprague-Dawley rats underwent 50% bladder volume reduction by suture closure of the bladder dome. T8-T10 spinal cord injury was done in select animals. Latency of the perigenital-bladder reflex, spontaneous voiding onset and body weight were measured. Cystometry using urethane anesthesia, and measurements of in vitro spontaneous and KCl evoked contractions were done.
Bladder reduction surgery led to the immediate appearance of spontaneous voiding in 1-week-old rats. Cystometry at 2 weeks showed voiding contractions in rats with bladder reduction, which was abolished by acute T8-T10 spinalization. Voiding contractions were not seen in animals with sham surgery or concurrent T8-T10 spinalization and bladder reduction. The perigenital-bladder reflex, somatic growth, spontaneous bladder contractions and bladder contractility were not affected by bladder reduction. Bladder capacity at 9 weeks was significantly larger in animals that underwent bladder reduction at 1 week than in sham treated animals (540 vs 256 microl, p = 0.04) but not in animals that underwent bladder reduction at 3 weeks.
Bladder reduction removes the central inhibition of spontaneous voiding in neonatal rats. This suggests that decreased neonatal bladder capacity may alter how the brain regulates the bladder.
The Journal of urology 11/2009; 183(1):370-7. · 4.02 Impact Factor
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Urology 10/2009; 75(3):514-5. · 2.43 Impact Factor
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ABSTRACT: Studies show that renal volume on magnetic resonance imaging correlates with differential function and is decreased in children with vesicoureteral reflux diagnosed after urinary tract infection. We examined the correlation between ultrasound renal parenchymal area and magnetic resonance imaging volume to determine whether quantitative ultrasound renal parenchymal area might be a reliable, less costly and less invasive substitute for renal magnetic resonance imaging volume.
To determine the correlation of ultrasound renal parenchymal area with magnetic resonance imaging, we identified 82 children with primary vesicoureteral reflux who underwent renal magnetic resonance imaging and ultrasound. Magnetic resonance imaging volume was compared with ultrasound renal parenchymal area, renal length and calculated ellipsoid volume. To determine the correlation of ultrasound renal parenchymal area with reflux grade, ultrasound renal parenchymal area was examined in 96 children with reflux and urinary tract infection, and in 52 with reflux without urinary tract infection. Linear regression and multivariate analysis were performed to find the relationship between ultrasound renal parenchymal area and reflux grade.
The correlation of ultrasound renal parenchymal area with magnetic resonance imaging volume was superior to that of renal length and calculated ellipsoid volume (r(2) = 0.90 vs 0.83 and 0.84, respectively). Hydronephrosis did not affect the correlation. On multiple regression analysis in children with reflux and urinary tract infection higher reflux grade correlated with decreased ultrasound renal parenchymal area (p = 0.0016). In children with reflux without urinary tract infection reflux grade did not correlate with decreased ultrasound renal parenchymal area (p = 0.47).
Ultrasound renal parenchymal area correlates closely with magnetic resonance imaging derived 3-dimensional renal volume and is capable of detecting progressive renal area loss in patients with reflux and urinary tract infection. More studies are necessary to verify whether data from more invasive tests, such as renal magnetic resonance imaging and dimercapto-succinic acid scan, may be attained from ultrasound renal parenchymal area alone.
The Journal of urology 09/2009; 182(4 Suppl):1683-7. · 4.02 Impact Factor
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ABSTRACT: An overview of recent findings in the postnatal development of lower urinary tract function is provided in the present paper. Neonatal animals depend on a perigenital stimulation-activated spinal reflex for voiding before adult bladder control emerges. The presence of myogenic spontaneous contractions may also be essential for bladder maturation. As the bladder matures, both the perigenital reflex and spontaneous contractions are downregulated after the first few postnatal weeks. Recent studies indicate that perigenital reflex downregulation and the emergence of the adult voiding reflex are two separate but well-coordinated processes. A critical period is present in the postnatal development of muscle contractility and neural control of the bladder. Increasing evidence indicates that myogenic spontaneous contractions of the neonatal bladders are regulated by muscarinic and purinergic mechanisms, which involve both the smooth muscle and the urothelium.
Lower urinary tract symptoms 08/2009; 1:S74 - S76. · 0.24 Impact Factor
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ABSTRACT: To review the current management of pediatric genitourinary rhabdomyosarcoma (RMS).
Studies performed by the Intergroup Rhabdomyosarcoma Study Group, Children's Oncology Group (COG), International Society of Paediatric Oncology (SIOP) and others over the past 10 years were reviewed to compare the use of surgery, chemotherapy, and radiotherapy for treatment of RMS and their associated outcomes.
Equivalent overall survival rates were reported in the last COG and SIOP trials, with worse event-free survival rates for bladder/prostate RMS in SIOP trials. The use of radiotherapy for local control was the main difference between current COG and SIOP protocols. Surgery is used to diagnose RMS, and for local control after chemotherapy. Chemotherapy is used for systemic control of RMS, but metastatic RMS will require new approaches.
Risk stratification and risk-based therapy are being studied to decrease morbidity from treatment of RMS. The proper role of surgery vs radiotherapy for local control and whether additional treatment with second-line chemotherapy outweighs the avoidance of radiotherapy remain to be defined.
Journal of pediatric urology 08/2009; 5(6):501-6. · 1.38 Impact Factor
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ABSTRACT: Nitric oxide (NO), a neurotransmitter in the lower urinary tract, stimulates soluble guanylyl cyclase (sGC) and in turn cGMP-dependent protein kinase G (PKG) to modulate a number of downstream targets. NO donors reduce bladder hyperactivity in some pathological models but do not affect normal bladder activity in the adult rat. In this study, the NO donor S-nitroso-N-acetyl-DL-penicillamine (SNAP; 100 microM) decreased the amplitude and frequency of spontaneous and carbachol-enhanced contractions in neonatal rat bladder strips, which are intrinsically hyperactive. This effect was blocked by inhibition of sGC and mimicked by application of a membrane-permeable cGMP analog (8-bromo-cGMP, 100 microM). Inhibition of PKG prevented or reversed the inhibitory effects of 8-bromo-cGMP. A portion of the SNAP-mediated inhibition was also dependent upon PKG; however, a short-lasting, sGC-dependent inhibitory effect of SNAP was still present after PKG inhibition. Inhibition of NO synthase with L-NAME (100 microM) did not change the amplitude or frequency of contractions. However, inhibition of endogenous phosphodiesterase (PDE)-5 with zaprinast (25 microM) reduced the amplitude and frequency of phasic contractions and increased the magnitude of inhibition produced by maximal concentrations of SNAP, suggesting that endogenous PDEs are constitutively active and regulate cGMP production. These results suggest that the NO-cGMP-PKG pathway may be involved in inhibitory control of the neonatal rat bladder.
AJP Renal Physiology 07/2009; 297(2):F333-40. · 4.42 Impact Factor
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ABSTRACT: We studied the possibility that age, height, weight and body mass index could be used to predict the likelihood of successful ureteroscopic access to the upper urinary tract without previous stent placement in prepubertal children.
We retrospectively reviewed all ureteroscopic procedures for upper tract calculi in prepubertal children from 2003 to 2007. We compared age, height, weight and body mass index in patients who underwent successful primary flexible ureteroscopic access and in those who required initial stent placement to perform ureteroscopy.
Successful primary ureteroscopic access to the upper tract was achieved in 18 of 30 patients (60%). There was no difference in mean age (9.9 vs 9.5 years, p = 0.8), height (132 vs 128 cm, p = 0.6), weight (37 vs 36 kg, p = 0.86) or body mass index (19.3 vs 20.5 kg/m(2), p = 0.55) between patients with successful vs unsuccessful upper tract access. Locations that prevented access to the upper urinary tract were evenly distributed among the ureteral orifice, iliac vessels and ureteropelvic junction.
Age, height, weight and body mass index could not predict the likelihood of successful ureteroscopic access to the upper tract. Placement of a ureteral stent for passive ureteral dilation is not necessary for successful ureteroscopic access to the renal pelvis in prepubertal children. An initial attempt at ureteroscopy, with placement of a ureteral stent if upper tract access is unsuccessful, decreases the number of procedures while maintaining a low complication rate.
The Journal of urology 09/2008; 180(4 Suppl):1861-3; discussion 1863-4. · 4.02 Impact Factor
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ABSTRACT: We sought to determine if initial computerized tomography findings in pediatric patients suffering blunt renal trauma with urinary extravasation were predictive of the need for operative intervention.
A total of 17 patients with grade IV blunt renal trauma and urinary extravasation were identified between 2000 and 2007. Each computerized tomogram was reviewed to determine location, size and number of sites of extravasation, as well as the presence of contrast material in the ipsilateral ureter. These findings were compared with subsequent ureteral stent placement, percutaneous urinoma drainage, angiographic embolization and nephrectomy.
A total of 13 male and 4 female patients (mean age 11.1 years) were identified. Eight patients (47%) required delayed intervention. Conservative treatment was unsuccessful in patients with absence of contrast material in the ipsilateral ureter and large separation of the upper and lower poles, and in 3 of 5 patients with multiple areas of extravasation and 4 of 5 patients with transfusion requirements. The diameter (9.6 vs 9.7 mm, p = 0.96) and location of extravasation were not predictive of subsequent intervention. Two of 5 patients with posterior extravasation required intervention, both for symptomatic urinoma.
Early ureteral stent placement may be considered for pediatric patients with blunt renal trauma who demonstrate absence of contrast material in the ipsilateral ureter, since clinical indications for stent placement will likely develop. Further study may show if wide separation of the upper and lower poles, multiple areas of extravasation and transfusion requirement are factors in the decision for early intervention.
The Journal of urology 05/2008; 179(4):1529-32; discussion 1532-3. · 4.02 Impact Factor
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ABSTRACT: We report our current outcomes for ureteroscopic management of pediatric stone disease.
We carried out a retrospective review of all ureteroscopic procedures for kidney or ureteral calculi performed between 2001 and 2005. Stone location and size, preoperative and postoperative stenting, intraoperative dilation, use of ureteral access sheath, stone-free rates and complications were noted.
A total of 100 patients (58% female, mean age 13.2 years) underwent 115 procedures. Stones were located in the renal pelvis in 6% of patients, upper pole in 10%, mid ureter in 11%, lower pole in 17%, proximal ureter in 19% and distal ureter in 37%. Mean stone size was 8.3 mm (median 7.0), with a mean of 1.5 stones per patient. Preoperative stenting was used in 54% of patients, and a stent was placed postoperatively in 76%. Ureteral coaxial dilators and ureteral access sheaths were used in 70% and 24% of patients, respectively. There were no major intraoperative complications, although 5 patients required stent placement for ureteral perforation or extravasation. One patient had a ureteral stricture requiring ureteral reimplantation. Mean followup was 10.1 months (median 2.6). Stone-free rate was 91% on followup ultrasound, abdominal radiography or computerized tomography. Seven patients required staged ureteroscopic procedures to achieve stone-free status. While the number of percutaneous nephrolithotomy and shock wave lithotripsy cases remained stable, the number of ureteroscopic cases increased 7-fold during this period.
Improved ureteroscopic access to stones throughout the pediatric urinary tract and stone-free rates that are comparable to the adult population have led to the adoption of ureteroscopy as first line therapy in children at our institution.
The Journal of Urology 12/2007; 178(5):2128-31; discussion 2131. · 3.75 Impact Factor
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ABSTRACT: We report our experience with ureteroscopy to treat lower-pole calculi in children.
A retrospective review was conducted of all ureteroscopic procedures for lower-pole stone disease at a pediatric institution from 2000 through 2005. A total of 13 girls and 8 boys with a mean age of 15 years (range 1-20 years) underwent flexible ureteroscopy for lower-pole calculi. The mean stone burden was 12 mm. Stone-free status was defined by postoperative abdominal radiography, CT, or ultrasonography.
Ureteral stenting was performed preoperatively in 38% and postoperatively in 71% of the patients. Ureteral-access sheaths were placed in 43%. There were no intraoperative or postoperative complications. With a mean follow-up of 11 months, 76% of the children were stone-free. The success rate for stones <15 mm was 93% v 33% for stones > or =15 mm (P = 0.01).
Ureteroscopy and laser lithotripsy are safe and effective in children with lower-pole calculi. Ureteroscopy can be considered a primary treatment option for children with lower-pole calculi <15 mm.
Journal of Endourology 11/2007; 21(10):1179-82. · 1.85 Impact Factor
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ABSTRACT: Recent reviews show that bicycles are the major cause of significant renal injury with few injuries occurring during contact sports. All-terrain vehicles are also responsible for significant pediatric renal trauma. We determined whether dirt bikes and all-terrain vehicles cause more significant renal injuries than contact sports.
A retrospective review of our pediatric trauma database revealed 115 consecutive patients treated for renal trauma from 2000 to 2005. A total of 20 bicycle injuries occurred, including 6 on dirt bikes. A total of 13 all-terrain vehicle injuries occurred, including 4 involving rollovers. A total of 12 contact sport injuries occurred, including 2 during pick-up games. The mean grade of renal injury was compared among the mechanisms, with grades III-V considered high grade.
In descending order of renal injury the mechanisms were dirt bike (2.8), all-terrain vehicle rollover (2.8), bicycle (2.3), all-terrain vehicle (2.1), contact sports (1.8) and organized contact sports (1.4). Dirt bikes and all-terrain vehicle rollovers caused significantly greater renal trauma than organized contact sports (2.8 vs 1.4, p = 0.007 and 0.02, respectively), whereas overall bicycle and all-terrain vehicle accidents resulted in similar renal trauma grades compared to those of all contact sports. The 2 high grade renal injuries during contact sports occurred during pick-up football games without protective gear.
Physician advice regarding children with a solitary kidney should include avoiding dirt bikes and all-terrain vehicles. Efforts to limit all-terrain vehicle use in children younger than 16 years would decrease the risk of significant renal injury in this population more effectively than limiting contact sports participation.
The Journal of Urology 11/2007; 178(4 Pt 2):1672-4. · 3.75 Impact Factor
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ABSTRACT: Spontaneous bladder contractions (SBCs) in the neonatal rat urinary bladder change from a high-amplitude, low-frequency pattern to a low-amplitude, high-frequency pattern during the first 6 wk of life. Understanding the mechanism of this developmental change may provide insights into the causes of bladder overactivity in adults. In vitro whole bladder preparations from Sprague-Dawley rats were used to study the modulation of SBCs by calcium-activated potassium channels (K(Ca)) and electrical field stimulation from 3 days to 6 wk of life. SBCs in 3-day-old bladders were unmasked by treatment with iberiotoxin (100 nM), an inhibitor of large conductance K(Ca) (BK) channels, or apamin (100 nM), an inhibitor of small conductance K(Ca) (SK) channels. Iberiotoxin significantly increased the magnitude of SBCs at 2-3 wk, whereas apamin was only effective at 6 wk. In 1-2 wk bladders, exposure to room temperature Krebs solution decreased SBCs. This decrease was reversed by activating intramural nerves with electrical field stimulation. The effect of electrical field stimulation was inhibited by atropine (1 microM), suramin (10 microM), or pretreatment with tetrodotoxin (1 microM) but was not reversed by tetrodotoxin applied after electrical field stimulation. BK-alpha mRNA increased threefold, and BK-alpha protein increased fivefold from 3 days to 6 wk. These data suggest that BK channels play an important role in the regulation of SBCs in the neonatal bladder and that both increased BK channel activity, as well as changes in smooth muscle sensitivity to locally released neurotransmitters contribute to the downregulation of SBCs during early postnatal development.
AJP Regulatory Integrative and Comparative Physiology 06/2007; 292(5):R2100-12. · 3.34 Impact Factor
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ABSTRACT: Tumor lysis syndrome is a potentially life-threatening complication of induction chemotherapy for treatment of lymphoproliferative malignancies. Serious complications of tumor lysis syndrome are rare with the preemptive use of allopurinol, rasburicase, and urine alkalinization. We report a case of oliguric acute renal failure due to bilateral xanthine nephropathy in an 11-year-old girl as a complication of tumor lysis syndrome during the treatment of T-cell acute lymphoblastic leukemia. Xanthine nephrolithiasis results from the inhibition of uric acid synthesis via allopurinol which increases plasma and urinary xanthine and hypoxanthine levels. Reports of xanthine nephrolithiasis as a cause of tumor lysis syndrome are rare in the absence of defects in the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) enzyme. Xanthine nephropathy should be considered in patients who develop acute renal failure following aggressive chemotherapy with appropriate tumor lysis syndrome prophylaxis. Urine measurements for xanthine could aid in the diagnosis of patients with nephrolithiasis complicating tumor lysis syndrome. Allopurinal dosage should be reduced or discontinued if xanthine nephropathy is suspected.
Pediatric Nephrology 02/2007; 22(1):132-5. · 2.52 Impact Factor
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ABSTRACT: In vitro preparations of whole urinary bladders of neonatal rats exhibit prominent myogenic spontaneous contractions, the amplitude and frequency of which can be increased by muscarinic agonists. The muscarinic receptor subtype responsible for this facilitation was examined in the present experiments. Basal spontaneous contractions in bladders from 1- to 2-wk-old Sprague-Dawley rats were not affected by M2 or M3 receptor antagonists. However, administration of 0.5 microM physostigmine, an anticholinesterase agent that increases the levels of endogenous acetylcholine, or 50-100 nM carbachol, a cholinergic agonist at low concentrations, which did not cause tonic contractions, significantly augmented the frequency and amplitude of spontaneous contractions. Blockade of M2 receptors with 0.1 microM AF-DX 116 or 1 microM methoctramine or blockade of M3 receptors with 50 nM 4-diphenylacetoxy-N-methylpiperidine methiodide or 0.1 microM 4-diphenylacetoxy-N-(2-chloroethyl)piperidine hydrochloride (4-DAMP mustard) reversed the physostigmine and carbachol responses. M2 and M3 receptor blockade did not alter the facilitation of spontaneous contractions induced by 10 nM BAY K 8644, an L-type Ca2+ channel opener, or 0.1 microM iberiotoxin, a large-conductance Ca2+-activated K+ channel blocker. NS-1619 (30 microM), a large-conductance Ca2+-activated K+ channel opener, decreased carbachol-augmented spontaneous contractions. These results suggest that spontaneous contractions in the neonatal rat bladder are enhanced by activation of M2 and M3 receptors by endogenous acetylcholine released in the presence of an anticholinesterase agent or a cholinergic receptor agonist.
AJP Regulatory Integrative and Comparative Physiology 11/2006; 291(4):R1049-59. · 3.34 Impact Factor
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ABSTRACT: We investigated the likelihood of finding vesicoureteral reflux (VUR) in patients with urinary tract infections (UTIs), accompanied by fever or dysfunctional elimination syndrome (DES).
Two hundred consecutive voiding cystourethrograms performed in 1997-2002 for a diagnosis of UTI were reviewed. Fever, DES, and the grade and laterality of VUR were recorded. Patients were stratified into two groups by age to allow for assessment of DES symptoms in the older patient population: <2 years (n=68) and > or =2 years (n=132). Ratios were compared using a two-tailed Fisher's exact test.
Of the children> or =2 years old, 64/132 (48%) had VUR. Patients who were non-febrile with DES were less likely than patients who were febrile without DES to have VUR [12/34 (35%) vs 23/34 (68%), P=0.02], whereas the risk of dilating VUR [5/34 (15%) vs 11/34 (32%), P=0.15] and bilateral VUR [4/34 (12%) vs 11/34 (32%), P=0.08] was not statistically different. In febrile patients, the presence of DES was associated with a lower risk of VUR [22/51 (43%) vs 23/34 (68%), P=0.03] and dilating VUR [5/51 (10%) vs 11/34 (32%), P=0.01], but not bilateral VUR [8/51 (16%) vs 11/34 (32%), P=0.11].
Children with non-febrile UTI and DES have a significantly lower risk of having VUR compared to children with febrile UTI and no DES. Among children with a history of UTI, DES is a negative predictor for VUR.
Journal of pediatric urology 08/2006; 2(4):312-5. · 1.38 Impact Factor
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ABSTRACT: Rat pups only void when the perigenital-bladder reflex is activated by the mother rat licking the perineum. Maternal separation causes bladder distention as well as stress responses and anxiety behaviors in adult rats. We determined if MS would change voiding reflex maturation in neonatal rats.
A total of 14 Sprague-Dawley rat pups were subjected to 6 hours of daily MS and 17 were subjected to 6 hours of MS with bladder emptying by perigenital stimulation at 3 hours on postnatal days 2 to 14. Age matched controls for the 2 groups remained with the mother. Spontaneous voiding in awake pups from 1 to 3 weeks was monitored in a metabolic cage and perigenital-bladder reflex latency was determined from 1 to 7 weeks. Cystometry was performed at 9 weeks with the rats under urethane anesthesia.
Spontaneous voiding began at 3 weeks in all animals. The latency of the perigenital-bladder reflex at 3 weeks was shorter than the latency at 2 days in MS animals (3.3 vs 6.4 seconds, p < 0.01) but not in control or MSPG animals. MS animals maintained the perigenital-bladder reflex 2 weeks longer than control animals. The spontaneous voiding behavior of MSPG animals was similar to that in controls.
Intermittent bladder distention delays withdrawal of the spinal perigenital-bladder reflex but it does not affect maturation of the supraspinal bladder-bladder reflex that controls spontaneous voiding in older rats. This suggests that increased bladder afferent firing can selectively modulate spinal but not supraspinal mechanisms controlling postnatal changes in voiding function.
The Journal of Urology 03/2006; 175(3 Pt 1):1148-51. · 3.75 Impact Factor
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ABSTRACT: Urethral atresia is a rare and usually fatal cause of prenatal bladder outlet obstruction. We present a case of urethral atresia with urinary ascites to highlight the difficulties in making the diagnosis in the absence of hydronephrosis. We also discuss possible reasons why this patient maintained normal renal and pulmonary function.
Urology 09/2005; 66(2):432. · 2.43 Impact Factor
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ABSTRACT: The management of Wilms' tumor continues to evolve with two different approaches being taken by the National Wilms Tumor Study in North America and the International Society of Pediatric Oncology in Europe in regards to preoperative chemotherapy. Limiting the duration, dosage, and number of chemotherapeutic agents and the dosage of radiotherapy are common goals in both trials.
Contralateral exploration of unilateral tumors will no longer be recommended in future National Wilms Tumor Studies. Percutaneous biopsy for tissue diagnosis is quite accurate, but there are concerning complications with its use. Partial nephrectomy is successful for low risk unilateral Wilms tumor, but its indications remain controversial. The surgical complication rate was similar between the National Wilms Tumor Study and the International Society of Pediatric Oncology, but intraoperative tumor spill was higher in the North American trials. Doxorubicin decreased the risk of recurrence in stage III tumors by 50%, and its current dose is not associated with late congestive heart failure. For selected patients, shorter courses of vincristine/dactinomycin or vincristine alone show equivalent results compared to current regimens. A longer course of chemotherapy (including doxorubicin) for clear cell sarcoma improves recurrence-free survival. Patients with Wilms' tumor, aniridia, major genitourinary malformations, and mental retardation, the WAGR syndrome, have a 50% chance of unexplained end-stage renal disease 20 years after treatment.
Less aggressive means of diagnosis and treatment for Wilms' tumor are continuing to achieve very good cure rates while lowering long term morbidity for low risk patients. High-risk patients with unfavorable histology or the WAGR syndrome benefit from more intensive treatment and long-term follow-up.
Current Opinion in Urology 08/2005; 15(4):273-6. · 2.59 Impact Factor
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ABSTRACT: The management of urolithiasis in children poses specific technical challenges that require planning before endoscopy and that affect the risks and outcomes of these procedures. The indications for operative intervention in children and adults are similar:infection, persistent symptoms of flank pain, nausea, and vomiting, as well as the failure to pass a ureteral stone after an appropriate trial of observation (3-6 weeks). Specific adjustments for performing extracorporeal shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy, and cystolithotomy in children are discussed.
Urologic Clinics of North America 09/2004; 31(3):589-94, xi. · 1.82 Impact Factor