Andrew Windsperger

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.

INCIDENCE AND RISK FACTORS FOR URETERAL STRICTURE AFTER PEDIATRIC RENAL TRANSPLANT: THE UNIVERSITY OF MINNESOTA EXPERIENCE

Management options range from percutaneous and ureteroscopic dilation and/or ureterotomy to ureteral reimplantation. Understanding of ureteral stricture management in the pediatric population is limited. We present a single-center experience with ureteral stricture in a large pediatric renal transplant cohort. METHODS: A retrospective review of the pediatric renal transplant database at our institution was conducted for the period