This Month in Pediatric Urology

Article Outline

• B7-H1 Expression for Wilms Tumor
• Bladder Deterioration After Bladder Outlet Procedures for Neuropathic Bladder Dysfunction
• Urinary Tract Infection After Injection Therapy for Vesicoureteral Reflux
• Nerve Sparing Robotic Extravesical Ureteral Reimplantation
• Copyright

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B7-H1 Expression for Wilms Tumor 

Successful management of Wilms tumor represents one of the great success stories in the treatment of childhood malignancies. Stratification of care and prognosis is currently based on a number of well established factors primarily related to favorable vs unfavorable histology and pathological tumor stage. In an effort to identify additional prognostic factors, Routh et al (page 1954) from Rochester, Minnesota investigated the association of the expression of the T cell co-regulatory ligand B7-H1 with the risk of tumor recurrence in 81 patients with Wilms tumor treated at the Mayo Clinic. Tumor recurrence was noted in 22% of patients and 14 died. Expression of B7-H1 was observed overall in 11 of the 81 (13.6%) patients, including 4 of 10 (40%) with anaplastic tumors and 7 of 64 (9.8%) with favorable histology tumors. Tumor B7-H1 expression was associated with a 2.7-fold increased risk of recurrence (p=0.06) overall and a 3.7-fold increased risk of recurrence (p=0.03) in tumors with favorable histology. The authors conclude that B7-H1 expression may prove useful for identification of high risk patients who could benefit from more intensive treatment regimens.

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Bladder Deterioration After Bladder Outlet Procedures for Neuropathic Bladder Dysfunction 

Progressive deterioration in bladder function following implantation of artificial urinary sphincters for neuropathic bladder has been well documented. Dave et al (page 1991) from Toronto, Canada have expanded our understanding of the risk of isolated bladder outlet procedures (BOP) for urinary incontinence in children with neuropathic bladders. From a retrospective chart review during a 10-year period the authors identified 15 consecutive children with neuropathic bladders who underwent various isolated BOP (Salle bladder neck procedure in 5, sling in 4, artificial urinary sphincter in 5, Young-Dees-Leadbetter procedure in 1) to treat refractory urinary continence associated with isolated outlet deficiency and adequate bladder storage function. Preoperatively bladder capacity was 89 ± 25% of the minimal acceptable capacity for age and 60 ± 18% of the predicted capacity for age. The below 20 and 30 cm H₂O filling pressure volumes were greater than 80% of bladder capacity in all patients and the detrusor leak point pressure was less than 40 cm H₂O in 12 of 15 children. Mean followup was 11.2 years. The initial BOP failed in 4 cases. Although 11 patients achieved initial dryness incontinence recurred in 9 and new onset hydronephrosis developed in 2. All 15 children ultimately required augmentation cystoplasty at a mean time of 39.6 ± 28 months postoperatively either for upper tract deterioration or a combination of upper tract deterioration and incontinence. The authors conclude that isolated BOP for neuropathic urinary incontinence has a poor long-term prognosis, with most patients ultimately requiring augmentation cystoplasty, which is not predicted adequately on preoperative urodynamics.

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Urinary Tract Infection After Injection Therapy for Vesicoureteral Reflux 

Although short-term success rates of endoscopic treatment of vesicoureteral reflux (VUR) have been well documented, long-term outcomes have received less attention. Chi et al (page 1966) from Dallas, Texas identified 175 patients more than 6 months (median 32 months, range 7 to 53 months) after initial successful (defined as a negative voiding cystogram 3 months after treatment) endoscopic treatment with dextranomer/hyaluronic acid copolymer. Post-injection symptomatic urinary tract infection (UTI) developed in 40 (24%) patients, including 20 (12%) with febrile UTIs. Repeat cystography in 15 patients with febrile recurrences revealed recurrent VUR in 7 (47%). Univariate and multivariate analyses of potential risk factors for recurrent UTI indicated that patients with more than 3 pre-injection infections were 8.5 times more likely than those with 1 pre-injection infection to have post-injection symptomatic UTI. These data suggest that there is a subset of patients with VUR who are at greater risk for recurrent febrile UTI after initial successful endoscopic treatment with dextranomer/hyaluronic acid copolymer, and that this subset has a significant late recurrence rate of VUR. More long-term prospective followup studies of endoscopic treatment of VUR are needed, and retrospective studies need to report longer term followup data.

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Nerve Sparing Robotic Extravesical Ureteral Reimplantation 

Voiding difficulties including urinary retention following open bilateral extravesical ureteral reimplantation for VUR have been documented, particularly in patients with preoperative voiding dysfunction. In an effort to avoid this complication, Casale et al (page 1987) from Philadelphia, Pennsylvania report their preliminary experience with 41 patients who underwent robotic extravesical reimplantation for bilateral VUR using a nerve sparing approach. Mean operative time was 2.44 hours (range 1.4 to 3.2) including cystoscopy and robotic setup. Average length of hospital stay was 26 hours (range 18 to 34). All patients had post-void residual urine volumes assessed after catheter removal, and all voided spontaneously with minimal to no post-void residual (mean 13 ml). Toilet-trained children had uroflow studies that were unchanged from preoperative uroflows. Postoperative ultrasound studies at 3 and 6 months were normal. Voiding cystography 3 months postoperatively documented successful correction of VUR in 40 of the 41 (97.5%). The authors conclude that robotic extravesical reimplantation is in its infancy and that, although time-consuming, a nerve sparing approach prevents postoperative bladder dysfunction.