Comparison Between Ambulatory and Conventional Urodynamics of the Modified Orthotopic Hautmann Neobladder

The aim of the present study was to determine the diagnostic accuracy of conventional and ambulatory urodynamic studies (UDS) in estimating neobladder function.

We evaluated 32 patients who underwent radical cystectomy and orthotopic Hautmann W neobladder with Abol-Enein-Ghoneim uretero-intestinal anastomosis for bladder cancer. The patients were initially examined by using both conventional and ambulatory UDS.

Conventional UDS detected a very high mean intravesical pressure at maximum capacity (53.7±17.5 cm H2O). By contrast, the mean intravesical pressure detected by using ambulatory UDS (which reflects the dominant pattern of pressure variation during filling) was significantly lower (34.4±5.2 cm H2O, P<0.001). The comparison between intravesical pressure at half of maximum capacity in conventional UDS and the mean value in ambulatory UDS did not show significant difference (P=0.152). The mean voided volume in conventional UDS was greater than both the mean voided volume (P<0.001) and the mean maximum voided volume in ambulatory UDS (P=0.001). However, this difference did not affect the postvoid residual urine volume measured in both studies (P=0.207). Moreover, incontinence episodes recorded in ambulatory UDS were more frequent but not statistically significantly different from those recorded in conventional UDS (P=0.332).

The estimation of neobladder function by means of ambulatory UDS seems to provide interesting research data for the mode of lower urinary tract function in patients with orthotopic substitution after radical cystectomy. The great high value in ambulatory UDS, in cases in which conventional UDS had failed, is due to the exposure of daily and nocturnal incontinence episodes, confirming our patients' complaints.