Detrusor contractility is believed to decrease with time. However, longitudinal study of the detrusor contractility after long-term follow-up is rare. This study investigated a cohort of male and female patients who had urodynamic study at baseline and more than 10 years later.

A total of 166 patients (49 men and 117 women) without bladder outlet obstruction (BOO) and 63 patients (54 men and 9 women) proven to have BOO who had received urodynamic study at baseline and > 10 years later. Patients who had neurogenic voiding dysfunction, previous pelvic surgery, who underwent lower urinary tract surgery or bladder lesions receiving treatment during the follow-up period were excluded. The urodynamic parameters including bladder first sensation of filling (FSF), full sensation (FS), urge sensation (US), cystometric bladder capacity (CBC), compliance, maximum flow rate (Qmax), detrusor pressure at Qmax (Pdet), voided volume, postvoid residual volume (PVR), bladder contractility index (BCI), and BOO index (BOOI) were compared between baseline and >10 years later.

The changes of urodynamic parameters between baseline and >10 years later revealed that Pdet was significantly decreased and PVR was significantly increased in men and women. FS, US, and voided volume were significantly decreased. BCI was also significantly decreased in men and women (Table 1). When we compared the 49 men without BOO and 54 men with BOO, decrease of Pdet, Qmax, voided volume, and BCI were significantly decreased in both groups. PVR was also significantly increased in both groups and was significantly greater in men with BOO after >10 years (p=0.036) (Table 2).

Detrusor contractility decreases in men and women after > 10 years follow-up. The decrease of detrusor contractility was similar between men with and without BOO. PVR was significantly increased in men with BOO after >10 years, suggesting a greater degree of urethral resistance in men with BOO after >10 years.

Detrusor contractility will decrease with time in both men and women. Men with BOO did not have higher rate of decreased contractility, but PVR increased more than men without BOO.