[Bladder accommodation disorders in children with posterior urethral valves].

On the basis of 8 special cases, the authors draw attention to the role of pathology of the bladder itself in the aetiogenesis of residual dilatations of the upper urinary tract after endoscopic treatment of posterior urethral valves. This pathology is dominated by impaired accommodation of the bladder with hypertonicity during filling. It is a second bladder disease, residual after section of the valve. The diagnosis may be made on the basis of two arguments: --narrowing of the upper tract when the bladder is kept permanently drained (in the absence of any vesico-ureteral reflux); --data from urodynamic examination (confirming the absence of any residual obstructive pathology in the cervico-urethral canal). The effects upon the upper urinary tract of this impaired vesical accommodation may be demonstrated by simultaneous urodynamic studies of the upper and lower urinary tract, but in practice urography findings (comparison between full bladder and empty bladder) and those of urodynamics are sufficient to make the diagnosis. It is thus possible to avoid an erroneous diagnosis of primary obstruction of the terminal ureter or of residual cervico-urethral obstructive pathology. This in turn avoids useless and dangerous ureterovesical reimplantations, endoscopic procedures involving the bladder neck or so-called residual valve tissue which no longer exists. Therapeutic approaches are reviewed. The respective roles of urinary bypass and of enterocystoplasty have not yet been clearly defined.