OBJECTIVE: To evaluate the effect of spinal anaesthesia on the bladder neck position and the urethral closure function in the resting state and during clinical stress test in healthy, continent women. DESIGN: Controlled clinical trial. SETTING: Department of Gynaecology and Obstetrics, Vienna University Medical School. PARTICIPANTS: Fourteen continent women, of which seven were nulliparous and seven parous, underwent minor gynaecological procedures under spinal anaesthesia. Urodynamics and ultrasound investigations were performed before and during spinal anaesthesia. MAIN OUTCOME MEASURES: Changes in the bladder neck position and the urethral closure function before and during spinal anaesthesia. RESULTS: Bladder neck position was found to be lower and more posterior during spinal anaesthesia as compared with pre-operative assessment. The posterior urethrovesical angle increased significantly both at rest and during maximum straining. We observed a significant increase in bladder compliance, and all parameters of the urethral pressure profile decreased significantly. While none of the nulliparous women had a positive clinical stress test during spinal anaesthesia, 4/7 parous women demonstrated leakage (Fisher's exact test, P = 0.003). CONCLUSIONS: Blockage of nerve supply to the pelvic floor muscles in continent women is associated with a significant loss of support of the bladder neck region confirming the theory of an active mechanism of muscular elements providing continence.
OBJECTIVE: To evaluate the effect of spinal anaesthesia on the bladder neck position and the urethral closure function in the resting state and during clinical stress test in healthy, continent women. DESIGN: Controlled clinical trial. SETTING: Department of Gynaecology and Obstetrics, Vienna University Medical School. PARTICIPANTS: Fourteen continent women, of which seven were nulliparous and seven parous, underwent minor gynaecological procedures under spinal anaesthesia. Urodynamics and ultrasound investigations were performed before and during spinal anaesthesia. MAIN OUTCOME MEASURES: Changes in the bladder neck position and the urethral closure function before and during spinal anaesthesia. RESULTS: Bladder neck position was found to be lower and more posterior during spinal anaesthesia as compared with pre-operative assessment. The posterior urethrovesical angle increased significantly both at rest and during maximum straining. We observed a significant increase in bladder compliance, and all parameters of the urethral pressure profile decreased significantly. While none of the nulliparous women had a positive clinical stress test during spinal anaesthesia, 4/7 parous women demonstrated leakage (Fisher's exact test, P = 0.003). CONCLUSIONS: Blockage of nerve supply to the pelvic floor muscles in continent women is associated with a significant loss of support of the bladder neck region confirming the theory of an active mechanism of muscular elements providing continence.