Management of the obstructed urinary tract associated with neurogenic bladder dysfunction

Abstract

The child with neurogenic bladder dysfunction may suffer from lower urinary tract obstruction, which, if untreated, can result in upper urinary tract deterioration. It is prudent to identify those newborns and infants who are at risk for upper urinary tract deterioration and advise an appropriate treatment protocol. In order to identify those children at risk, a thorough examination is required, along with appropriate upper urinary tract imaging studies and urodynamic assessment of the bladder. Infants and children at risk for upper tract deterioration are those who have intermittent or continuous detrusor pressure elevation above 40 cm H2O. We have identified the safe period, which is the time during which the bladder remains at a pressure lower than 40 cm H2O. Our management protocol for each child is individualized and based on increasing the safe period. The safe period can be increased with a combination of intermittent catheterization, administration of medications, and, in some cases, surgical reconstruction. With compulsive evaluation and intensive management, many of the previous upper urinary tract changes associated with the obstructed neurogenic bladder can be averted. With the above factors in mind, we have defined the period of bladder filling and storage where the pressure is below 40 cm H2O as the safe period. The ideal bladder for maintenance of normal upper tracts would have a long safe period and low voiding pressure. Our treatment protocol for the neurogenic bladder is therefore dependent on identifying those children who have very short or nonexistent safe periods. These are the children who are at risk for upper tract deterioration.