This Month in Pediatric Urology

Article Outline

• Should a Voiding Cystourethrogram be Performed for Persistent Prenatal Hydronephrosis?
• Robot Assisted Laparoscopic Partial Nephrectomy
• Effect of Tamsulosin on Systemic Blood Pressure
• Copyright

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Should a Voiding Cystourethrogram be Performed for Persistent Prenatal Hydronephrosis? 

The management of vesicoureteral reflux continues to evolve, and investigations are under way to determine whether treatment of early diagnosed vesicoureteral reflux is beneficial. It is now being questioned whether identifying vesicoureteral reflux in an asymptomatic child is even warranted. Estrada et al (page 801) from Massachusetts evaluated infants with a prenatal diagnosis of hydronephrosis in an attempt to assess the value of identifying vesicoureteral reflux and the need for prophylaxis. Although they acknowledge that vesicoureteral reflux is reported to occur in 17% to 38% of children with prenatally diagnosed hydronephrosis, their initial impression was that Society for Fetal Urology grade II hydronephrosis did not warrant postnatal screening with a voiding cystourethrogram (VCUG).

The authors retrospectively reviewed 1,514 records of neonates with a diagnosis of prenatal grade II hydronephrosis seen at their institution from 1998 to 2006. The grade of hydronephrosis was established between ages 3 and 6 weeks. Of the children 1,150 were screened with a VCUG and 364 were not. There was no specific randomization and the decision for a VCUG was based on the philosophy of the treating physician. Children were given prophylactic antibiotics before the VCUG which were continued if reflux was identified. The authors calculated an expected rate of reflux and risk of urinary infection based on the number of children screened with a VCUG who had those conditions. The calculated values were compared to the actual number of infections that occurred in the children not screened.

Vesicoureteral reflux was found in 322 of the neonates screened and it was not necessarily associated with the side of hydronephrosis. In the screened group a breakthrough urinary tract infection occurred in 5 of the 322 children with reflux and a febrile urinary infection occurred in 11 of 828 without reflux. Therefore, it was predicted that of the 364 children who did not undergo screening 101 would have reflux and 5 would have a febrile urinary infection. In fact, 16 patients in the group not screened had a febrile urinary infection. When the unscreened population was evaluated with a VCUG 12 children were found to have vesicoureteral reflux. The increased incidence of febrile urinary infections compared to that predicted in the nonscreened group was statistically significant. The authors conclude that the potential for vesicoureteral reflux justifies prophylactic antibiotics until a VCUG is obtained. In addition, neonates with grade II hydronephrosis should be screened for vesicoureteral reflux with a VCUG.

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Robot Assisted Laparoscopic Partial Nephrectomy 

Minimally invasive surgery in pediatrics is gradually becoming mainstream, and laparoscopic techniques have been perfected for partial nephrectomy. Lee et al (page 823) from Massachusetts and Virginia evaluate the safety and feasibility of robotic assisted laparoscopic partial nephrectomy (RALPN). Between 2002 and 2005 they performed 9 RALPNs for a nonfunctioning upper pole segment due to an ectopic ureter (4), a nonfunctioning lower pole refluxing segment (4) and cystic malformation of the upper pole (1). A transperitoneal approach was used in all cases. A 12 mm camera port was placed at the umbilicus, a second port was placed approximately 10 cm superior to the umbilicus, a third port was positioned in line with the anterior superior iliac spine, and a fourth port was used to retract the liver if a right lesion was approached. The kidney was exposed after reflecting the colon. The ureter of the involved segment was identified, ligated, transected and then used as a handle. Blunt dissection was used to separate the nonfunctioning pole from the normal parenchyma with final separation established with either electrocautery or the harmonic scalpel.

Blood loss during RALPN was described as minimal, and no intraoperative or postoperative blood transfusions were required. Postoperatively an asymptomatic urinoma developed in 1 child and an umbilical port site infection occurred in another. The robotic operative time (mean 275 minutes) was prolonged compared to the authors' experience with an open procedure. However, their data indicate that improvement in operative time with the robot follows a fairly linear learning curve. There was a similar length of stay (2.9 days) for robotic, laparoscopic and open techniques. Postoperative narcotic requirement was not different among the procedures.

The authors appropriately caution against drawing too many conclusions based on this small group of children, particularly since the study was retrospective and not age matched. The practical benefits of RALPN have not been established but the authors demonstrate that the technique is safe and successful. As expected, a learning curve exists and the procedure appears more challenging in the young child. As the learning curve continues to improve, operative time for the procedure will decrease. However, RALPN in children may never approach the benefit reported for adults.

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Effect of Tamsulosin on Systemic Blood Pressure 

Voiding dysfunction in children remains a complex disorder with multiple therapeutic options used in the treatment of abnormal lower urinary tract symptoms. Recently there has been interest in treating children with a nonselective α1 adrenergic antagonist particularly when symptoms primarily consist of bladder outlet obstruction. However, little is known regarding the true therapeutic benefit of this pharmacologic management and its safety, especially as it relates to hypotension. VanderBrink et al (page 817) from New York investigate the efficacy and safety of tamsulosin, an uroselective α1_A adrenergic antagonist, given to 12 girls and 11 boys 5 to 16 years old between 2004 and 2005. The children had been prescreened with a history, physical examination, voiding diary, urinalysis and urine culture. Previous medical management included treatment of dysfunctional bowel elimination. Uroflowmetry with placement of perineal electrodes was performed in all children to assess pelvic floor electromyography. Ultrasonography was used to assess bladder capacity and post-void residual urine. The 23 children did not respond to traditional medical therapy and had an abnormal uroflow pattern but did not have detrusor sphincter dyssynergia or excessive pelvic floor activity. Initial dose was 0.2 mg tamsulosin orally at bedtime which was increased to 0.4 mg. Blood pressure was assessed in a sitting position before initiation of medication and throughout treatment. Uroflowmetry, blood pressure measurements and a voiding diary were repeated in 4 weeks.

During treatment there was a significant decrease in micturition and incontinent episodes based on voiding diaries and an increase in urinary flow rates. Although post-void residual improved with tamsulosin, an unexpected lower total voided volume was noted compared to pre-study baseline levels. Weekly incontinent episodes improved by 86%, daily micturition episodes improved by 40% and flow rates increased by 30% over baseline. The authors note that α1 receptors influence lower urinary tract function through a direct effect on smooth muscle at the bladder neck and a more generalized effect on the bladder and external sphincter. Recognizing that the timing of administration of tamsulosin can influence the outcome of blood pressure, the medication was given at bedtime to potentially minimize the side effect of hypotension. The authors did not find any objective hypotensive data when assessing the children in a sitting position, and acknowledge the limitations to assessing hypotension based on the time taken and patient position. In addition, there were no subjective symptomatic reports of adverse events. The authors conclude that selectively using tamsulosin in children with lower urinary tract symptoms in the absence of pelvic floor hyperactivity or sphincter dyssynergia is a safe and apparently effective treatment modality.