URETHRAL SPHINCTER VOLUMES IN WOMEN WITH OBSTRUCTED VOIDING AND ABNORMAL SPHINCTER ELECTROMYOGRAPHIC ACTIVITY

Objective To investigate the role of transrectal ultrasonography (TRUS ) of the female urethral sphincter and to compare sphincter volumes in controls and women With obstructed voiding associated with abnormal m yotonic-like electromyographic (EMG) activity in the urethral sphincte r. Patients and methods Fourteen women patients (mean age 29+/-3.2 yea rs) with symptoms of urinary outlet obstruction underwent videocystome trography (VCMG), urethral sphincter EMG and TRUS. Their sphincter vol umes were compared with those obtained from 20 age-matched control pat ients with other urodynamic diagnoses or normal urodynamics. Results I n every patient the urethral sphincter was identified as an ovoid, hyp oechoic structure distal to the bladder outlet. The mean volume of the sphincter in those patients with abnormal EMG activity (3.05+/-0.23 c m(3)) was significantly greater than that in the control group (1.30+/ -0.09 cm(3); P<0.001). Conclusion TRUS provided a useful method of ima ging the urethral sphincter in women. The results suggest that there w as an increase in the volume of the urethral sphincter in females with obstructed voiding, providing collateral evidence that the abnormal E MG activity is a significant factor in the pathophysiology of the diso rder.