The anatomical change of pelvic structure in varying degrees of cystocele may influence the bladder function. The present study aims to evaluate and compare the alteration of bladder function according to varying degrees of cystocele by using the urodynamic study results.

In the present study, 86 women with cystocele who underwent urodynamic study between November 2008 to July 2015 were included. To assess whether the urodynamic results were influenced by the grade of cystocele, the patients were classified into four grades according to pelvic organ prolapse quantification (POPQ) of the International Continence Society (ICS). The patients were evaluated with history taking, a physical examination, uroflowmetry, and urodynamic study. Using the urodynamic study, the bladder capacity, maximum detrusor pressure (Max-Pdet), maximum flow rate (Qmax), postvoiding residual volume (PVR) were measured. The variables of each cystocele grade were compared by using the one-way analysis of variance (ANOVA). Also, Pearson's correlation test was performed to evaluate the linear correlation of each variable according to cystocele severity.

The number of patients with cystocele grade I, II, III, and IV was 15, 37, 21, and 13, respectively. Basic characteristics and urodynamic study results of the patients in each cystocele grade are listed in Table 1. In one-way ANOVA, PVR was the only variable showing a significant difference between the cystocele grades (p <0.001, Table 1). The post-hoc of one-way ANOVA revealed that significant PVR difference was shown in only 3 pairs of cystocele grades as follows: grade I and III, I and IV, and II and IV (Figure). According to the correlation analysis, PVR showed a significant positive correlation with cystocele (r = 0.50, p <0.001).

Among the urodynamic parameters, PVR was the only variable that presented a significant change according to the severity of cystocele. Such change of PVR value was positively correlated to cystocele severity, which implies that PVR significantly tends to increase in higher degree of cystocele. The result is assumed to be attributed to the anatomic angulation of urethra as the bladder descends downwards from the pelvic cavity that may cause bladder outlet obstruction leading to larger PVR. Another assumption for the reason of such result is that since bladder protrudes out of pelvic cavity, the bladder may not gain a sufficient pressure from pelvic cavity to squeeze urine out of the body. Further studies are necessary to reveal the actual mechanism of our study result.

Postvoid residual tends to increase significantly with the increase of cystocele severity.