Nonobstructive Dilatations of Upper Urinary Tract in Children

From the etiologic standpoint, dilatations of the upper part of the urinary tract in children may be divided into three groups: (1) those due to mechanical obstruction, most frequently congenital fibrosis, muscular hypertrophy or exaggerated constriction at the points of normal anatomic narrowing, the ureteropelvic and ureterovesical junctions and the vesical outlet; (2) those that are a sequence of neurologic lesions either central or peripheral involving the bladder, such as poliomyelitis, cerebrospinal syphilis, spina bifida, toxic neuritis or the less definite dysfunctions classified as idiopathic; (3) those in which no obvious cause either mechanical or dynamic can be demonstrated. The confusion which exists concerning the pathogenesis of the dilatations in the last group is attested by the variety of terms used to describe them. Speculation as to etiology is usually divided between embryologic developmental, intrinsic inflammatory or neurogenic causes. It has included the contention that the dilatation is the result