2.2. Cystometry investigation
All the protocol of cystometry complied with the guidelines of the International Continence Society (ICS)17. Briefly, a multi-channel urodynamic study, in which warm saline (37 °C) was continuously infused (80 ml/min) into the bladder of patients, was recorded (MMS UD-200, Medical Measurement System, Enschede, Netherlands) and analyzed (Biopac MP36, Biopac Systems, Santa Barbra, US) using data-acquisition systems. The detrusor pressure (Pdet), abdominal pressure (Pabd), vesical pressure (Pves), urethral flow (Flow), infused volume (Vinf), voided volume (Vvod), and intra-vesical volume (Vive) were online recorded.