Cystometric evaluation of reconstructed classical bladder exstrophy

To evaluate the association of urodynamic variables with continence and upper tract status after reconstruction in patients with classical bladder exstrophy.

Thirty-one patients with bladder exstrophy were assessed 1 year after a modified bladder neck reconstruction. The evaluation included a detailed history, radioisotope renography, voiding cysto-urethrography, ultrasonography and artificial slow-filling cystometry.

Fifteen of the 31 patients were satisfactorily continent; their maximum cystometric capacity was higher than that of the incontinent patients. The compliance, assessed as the maximum bladder capacity at a detrusor pressure of < 20 cmH2O, was significantly higher in the continent patients. There was a 45% incidence of unstable contractions in the 31 patients. Persistent sphincteric activity was detected on electromyography in 10 patients during voiding. Twenty-one patients could initiate a detrusor contraction during voiding. The residual volume was significant in nine of the 21 patients who attempted to void. Patients with a high end-fill pressure (> 40 cmH2O) had a significantly higher incidence of unobstructive hydronephrosis than had patients who had an end-fill pressure of < 40 cmH2O.

Bladder abnormalities are common after reconstruction of bladder exstrophy, with poor compliance, small capacity and unstable contractions. These factors hinder any increase in capacity and cause persistent incontinence. Hypocompliance and high end-fill pressure can lead to upper tract damage even in continent patients. Detailed urodynamic evaluation is vital to assess the results and to plan subsequent treatment.