Cross-sectional study of determinants of upper and lower urinary tract outcomes in adults with spinal dysraphism--new recommendations for urodynamic followup guidelines?

PURPOSE

Although annual urodynamic study is currently recommended for all adults with spinal dysraphism, this followup might be overly intensive. Therefore, in this cross-sectional study we examine which determinants of upper and lower urinary tract outcomes are associated with relevant urodynamic findings.

MATERIALS AND METHODS

All patients visiting our specialized outpatient clinic for adults with spinal dysraphism during a 26-month period underwent evaluation of the lower urinary tract by (video)urodynamic study. High end filling pressure (40 cm H2O or greater), poor compliance (less than 10 ml/cm H2O) and high detrusor leak point pressure (40 cm H2O or greater) were classified as relevant findings and together called unsafe bladder. Multivariable analysis was performed to reveal determinants of unsafe bladder (type of spinal dysraphism, being wheelchair bound, hydrocephalus, urological symptoms and renal dilatation) and diagnostic accuracy was calculated for the significant determinants.

RESULTS

Of the 134 patients evaluated (median age 31.5 years) 120 underwent complete urodynamic study and were included in this study. In the multivariable model unsafe bladder was significantly associated with being wheelchair bound (OR 5.36, p=0.008). In patients without symptoms who were not wheelchair bound the negative predictive value of urodynamic study for finding an unsafe bladder was high (1.00).

CONCLUSIONS

If an adult patient with spinal dysraphism is not wheelchair bound, unfavorable findings at urodynamic study are unlikely. If these patients are asymptomatic, these findings are even more unlikely. In these patients it is probably not necessary to perform urodynamic study as frequently as is currently recommended. Patients with an unsafe bladder need active surveillance and treatment when upper tract safety is threatened.