This Month in Pediatric Urology

Article Outline

• Renal Damage Associated With Unilateral Vesicoureteral Reflux
• Partial Response to Intranasal Desmopressin is Related to Persistent Nocturnal Polyuria on Wet Nights
• Pathophysiology and Management of Overactive Bladder
• Extended Urethral Mobilization in Incised Plate Urethroplasty for Severe Hypospadias
• Proximal Hypospadias With Severe Chordee
• Safety and Efficacy of Intratesticular Injection of Vital Dyes During Varicocelectomy
• Copyright

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Renal Damage Associated With Unilateral Vesicoureteral Reflux 

Renal defects associated with vesicoureteral reflux may result from post-infectious renal damage or scarring and/or congenital renal dysplasia. Polito et al (page 1043) from Naples, Italy retrospectively analyzed changes in the refluxing kidney in 74 children with unilateral primary vesicoureteral reflux diagnosed after a urinary tract infection (UTI) or hydronephrosis. Differential uptake was less than 45% on a dimercapto-succinic acid (DMSA) scan 4 to 6 months after the last UTI, and contralateral renal sonogram and DMSA scan were normal. The goal was to study the variations in relative function of the refluxing kidney with time by DMSA scan. Mean patient age at study entry was 3 years and mean age at last followup was 11.9 years. The mean differential function of the refluxing kidney was 27% at study entry and 26.5% at the last visit. During followup an increase in differential uptake between 5% and 8% occurred in 3 patients. In contrast, a decrease in uptake of greater than 5% was observed in 6 patients, with 4 having a decrease between 13% and 27%. The average number of febrile UTIs in those with a significant decrease in differential uptake during the study period was similar to the number in children with a stable differential uptake. The authors conclude that the differential uptake generally remains stable over time but may decrease even in the absence of a UTI.

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Partial Response to Intranasal Desmopressin is Related to Persistent Nocturnal Polyuria on Wet Nights 

Although clinical trials have shown that desmopressin is more effective than placebo in 70% of patients with monosymptomatic nocturnal enuresis, only 30% are full responders. Raes et al (page 1048) from Ghent, Belgium studied the urine output on wet nights in children with nocturnal enuresis and a partial response to desmopressin. A total of 39 patients 7 to 19 years old with nocturnal enuresis and nocturnal polyuria (nocturnal urine output greater than 130% of maximum voided volume) were recruited for the study. All patients were treated with intranasal desmopressin for at least 3 months. The baseline nocturnal urine output averaged 439 ml and the maximum voided volume averaged 346 ml. During desmopressin treatment, nocturnal urine output on wet nights averaged 405 ml, whereas on dry nights it averaged 241 ml. During treatment the average nocturnal urine output on wet nights was not significantly different from that at baseline. The authors conclude that persistence of nocturnal polyuria on wet nights in partial responders to desmopressin may be related to an insufficient antidiuretic effect, poor compliance, suboptimal dosing or poor bioavailability of desmopressin.

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Pathophysiology and Management of Overactive Bladder 

The overactive bladder syndrome is the most common form of voiding dysfunction in children but it is poorly understood. Franco (pages 761 and 769) from Valhalla, New York discusses new concepts of the pathophysiology and treatment strategies of this condition in 2 review articles. He emphasizes that individuals with an overactive bladder often have associated organ dysfunction, including constipation as well as sexual and ejaculatory dysfunction, and disorders of mood and behavior, suggesting that the condition may be corticocentric. Magnetic resonance imaging and positron emission tomography in these individuals should improve our understanding of the role of central neurotransmitters including serotoninergic and dopaminergic pathways. The author discusses the roles of alpha blockers, treatment of constipation, botulinum A toxin, biofeedback, urethral over distension, sacral neurostimulation and peripheral nerve stimulation in individuals with an overactive bladder.

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Extended Urethral Mobilization in Incised Plate Urethroplasty for Severe Hypospadias 

Multiple techniques are available for the repair of proximal hypospadias. Bhat (page 1031) from Bikaner, India retrospectively reviewed his experience with 34 boys with proximal hypospadias treated with incised plate urethroplasty and significant mobilization of the proximal urethra up to the bulbar region to correct penile curvature. Mean patient age was 5 years. Penile curvature was corrected by this technique in 73% of the patients, 15% required mobilization of the urethral plate to the glans, 6% underwent dorsal placation and 6% underwent transaction of the urethral plate. At followup a fistula had developed in 9% of the cases and meatal stenosis in 3%. No patient had residual chordee. The author concludes that mobilization of the urethral plate improves the versatility of incised plate urethroplasty for proximal hypospadias.

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Proximal Hypospadias With Severe Chordee 

There are several options for correction of penile curvature in boys with proximal hypospadias, including dorsal placation, corporeal rotation, urethral plate mobilization, lengthening of the ventral penile surface and penile disassembly. Kajbafzadeh et al (page 1036) from Tehran, Iran reviewed 18 cases of perineal or penoscrotal hypospadias and severe ventral curvature. Penile curvature was corrected with a tunica vaginalis free graft without transecting the urethral plate, followed by hypospadias repair using the tubularized incised plate technique. Nearly all boys received preoperative testosterone injections. The tunica vaginalis graft was 1.5 times larger than the appropriate size of the ventral surface of the corpus cavernosum. The urethroplasty was done as a single stage procedure in 13 cases, a transverse preputial island flap urethroplasty was performed in 3 because the urethra was too short and a staged urethroplasty was performed using penile tissue expanders in 2. Mean patient age was 16 months, and mean followup was 27 months. At followup significant bleeding had occurred in 1 patient, which was managed nonoperatively, a small scrotal hematoma had developed in 1. Two patients had mild residual curvature, 1 had a urethrocutaneous fistula and 1 had meatal stenosis. The authors conclude that tunica vaginalis free graft is a viable option for the management of severe chordee but emphasize the need for long-term followup.

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Safety and Efficacy of Intratesticular Injection of Vital Dyes During Varicocelectomy 

One of the more common complications of varicocelectomy is postoperative hydrocele formation, which has been attributed to transection of testicular lymphatics in the spermatic cord. Injection of vital dyes around or into the testis has been reported during varicocele repair to help identify lymphatics. Makari et al (page 1026) from Washington, D.C. performed an experimental study in Sprague-Dawley rats to evaluate the efficacy and safety of transcrotal intratesticular injection of vital dyes. Lymphatics were not visualized following injection with trypan blue or low volume 25% methylene blue. Lymphatics were visualized following injection with 50% or 100% methylene blue and isosulfan blue. When the injected testes were examined 3 months later, pathological changes, including dystrophic calcification, basement membrane thickening, tubular atrophy, necrosis and hyalinization, were observed with all of the dyes. The authors conclude that intratesticular injection of vital dyes during varicocelectomy should be discouraged.