Posterior urethral valve treatments and outcomes in children receiving kidney transplants.

PURPOSE: We evaluated the impact of surgical approaches to posterior urethral valves on renal transplant survival and compared transplant survival in children with vs without posterior urethral valves. MATERIALS AND METHODS: We reviewed the records of all children who underwent renal transplantation from January 1984 to March 2008 and performed univariate subgroup analysis in those with posterior urethral valves. We evaluated the ureteroneocystotomy method, immunosuppression and valve treatment. In patients with posterior urethral valves we regarded nocturnal and/or daytime incontinence, severe urgency and the need for intermittent catheterization or double voiding for increased post-void residual urine as signs of bladder dysfunction. RESULTS: The initial renal transplant was received by 418 children at a mean age of 5.6 years. The 59 boys with posterior urethral valves received a total of 69 kidneys. By 8-year followup the kidney had failed in 24 of 59 boys with and 143 of 359 without posterior urethral valves (OR 0.9665, 95% CI 0.5462-1.692, p = 0.9105). Immunosuppression was consistent in the 2 groups. Outcomes were similar across all ureteroneocystotomy techniques. Initial management for posterior urethral valves was valve ablation alone in 12 boys, vesicostomy in 7 and supravesical diversion in 11. There was no difference in transplant survival or bladder dysfunction based on valve intervention. In 18 boys (55%) we noted overlapping signs of bladder dysfunction, of whom 11 performed intermittent catheterization or had increased post-void residual urine, 4 had severe urgency, 4 had daytime incontinence and 7 had nocturnal incontinence. Bladder dysfunction did not predict increased graft loss (OR 3.306, 95% CI 0.7615-16.27, p = 0.1134). CONCLUSIONS: Of children who undergo renal transplantation boys with posterior urethral valves do not have a higher graft failure rate. Treatment for posterior urethral valves did not significantly impact transplant survival or bladder dysfunction.

Risk factors and treatment success for ureteral obstruction after pediatric renal transplantation.

PURPOSE: Risk factors and treatment efficacy for ureteral obstruction following pediatric renal transplantation are poorly understood. We describe a single center experience with pediatric transplant recipients in an effort to discern risk factors and treatment efficacy. MATERIALS AND METHODS: We retrospectively reviewed the pediatric renal transplant database at our institution from January 1984 to March 2008. Donor and recipient demographics, treatment indications, graft characteristics, surgical techniques, treatment course, complications and graft outcomes were abstracted from clinical records. RESULTS: A total of 449 children (mean age 8.6 years) who underwent 526 renal transplants were included in the study. Ureteral obstruction requiring intervention developed in 42 cases (8%). Recipient age and gender, recipient and donor race, donor harvest technique, ureterovesical anastomosis with or without stenting, number of donor arteries, number of human leukocyte antigen mismatches, prior renal transplant and ischemia time were not significantly associated with increased incidence of ureteral obstruction. Renal failure secondary to posterior urethral valves was the only parameter significantly associated with increased incidence of ureteral obstruction (univariate OR 4.93, p = <0.0001; multivariate point estimate 7.59, p <0.0001). Of patients with ureteral obstruction 48% presented within 100 days after transplant. Kaplan-Meier analysis showed significantly decreased ureteral obstruction-free survival in patients with vs without posterior urethral valves (log rank test, p <0.0001). Ureteral obstruction, stenting and dilation were not significantly associated with increased graft loss or patient death. CONCLUSIONS: Ureteral obstruction after renal transplantation in children is a challenging complication that demands clinical vigilance. Posterior urethral valves appear to be a significant risk factor for post-transplant ureteral obstruction likely due to local factors such as ischemia, thick bladder wall and collagen remodeling.

Complex cloacal anomaly in discordant monozygotic twins.

Urorectal septum malformation sequences are rare congenital malformations. We report a case of persistent cloaca prenatally diagnosed at 26 weeks of gestation in 1 of a set of discordant monozygotic twins. The affected fetus at birth had a phallus-like structure, bladder outlet obstruction, an imperforate anus, and uterine distension. Diverting colostomy, vesicostomy, and percutaneous colpostomy tube were initially placed before definitive posterior sagittal anorectovaginoplasty was completed. A cloacal anomaly occurring in only 1 of a set of monozygotic twins is an exceedingly rare event.