The relevance of urethral resistance in children with myelodysplasia: Its impact on upper urinary tract deterioration and the outcome of conservativemanagement

Purpose: Upper urinary tract deterioration such as vesicoureteral reflux an d hydronephrosis, affects the long-term prognosis in children with myelodys plasia. We retrospectively analyzed the relevance of urethral resistance to upper tract deterioration in untreated children with myelodysplasia as wel l as the outcome of conservative treatment based on urethral resistance. Materials and Methods: Included in our study were 32 boys and 29 girls with a mean age at presentation of 3.6 years and a mean followup of 9.2 years. The children were divided into group 1-31 with high and group 2-30 with low urethral resistance, as determined by leak point pressure or maximum ureth ral closing pressure. Clean intermittent catheterization with or without an ticholinergics was instituted in all children in group 1 and those in group 2 with documented upper tract deterioration and/or problematic urinary inc ontinence after school age. We compared the incidence of upper tract deteri oration at the initial evaluation and during followup as well as the final status of the upper tract in the 2 groups. Results: At the initial evaluation 17 of 31 group 1 (55%) and 4 of 30 group 2 (13%) patients had upper tract deterioration (p <0.01). Deterioration wa s refractory to conservative management in 5 group 1 children who required bladder augmentation. The incidence of de novo upper tract deterioration du ring followup was not statistically different in the 2 groups (10 and 7% in groups 1 and 2, respectively). At the final evaluation the upper tract was normal in 26 (84%), improved in 3 and stable in 2 group 1 patients, while it was normal in 26 (87%) in group 2. Conclusions: Urethral resistance is relevant to upper tract deterioration i n untreated children with myelodysplasia. Although bladder augmentation was necessary in some children with high urethral resistance, the outcome of c onservative treatment was generally satisfactory with the preservation or n ormalization of the upper tract in more than 80% regardless of urethral res istance.