Urethral Movement Research Articles

The urethral motion profile: A novel method to evaluate urethral support and mobility

Urethral hypermobility is one of the theories developed to explain stress urinary incontinence. Traumatic damage to urethral supports during vaginal childbirth may be an important contributor. To establish a methodology to study urethral mobility, to determine the urethral motion profile in a cohort of young nulliparous women, and to determine changes in urethral mobility after childbirth. Ultrasound volume datasets of 44 nulligravidae and the 4D antepartum and post-partum datasets of 73 nulliparous women were assessed using post-processing software. Volumes were acquired translabially, at rest and on Valsalva, after voiding while supine. We marked six equidistant points from bladder neck to external urethral meatus and determined the position of these points relative to the inferoposterior symphyseal margin. Mobility vector distances for these points were determined by the formula radical{(Vy - Ry)(2)+ (Vx - Rx)(2)} (V = Valsalva; R = rest). Reproducibility was determined in a test-retest series of 21 patients. Changes in urethral mobility after delivery were determined by comparing antepartum and post-partum mobility vectors. The method was highly reproducible, with an intraclass correlation coefficient of 0.80 (confidence interval 0.73-0.86) for mobility vectors. The distal urethra was consistently found to be less mobile than the proximal part (P < 0.001). After childbirth, urethal mobility was significantly increased in five out of six segments. There was a trend towards more marked changes in mobility after vaginal operative delivery. Urethral mobility can be studied using 3D/4D translabial ultrasound. There is an increase in urethral mobility after childbirth, especially after instrumental delivery, suggesting an alteration in urethral support. This increase in mobility seems to affect the entire urethra.

Ultrasound imaging of the lower urinary tract after successful tension‐free vaginal tape (TVT) procedure

To evaluate changes in the mobility of the whole urethra, in the proximal urethra (funneling) and in the thickness of the urinary bladder wall, after a successful tension-free vaginal tape (TVT) procedure. This prospective longitudinal study included 52 women with urodynamically confirmed stress urinary incontinence who had undergone a successful TVT procedure. Ultrasound examination was performed before the TVT procedure and at a median of 3 (range, 3-6) months after surgery. For all women, the changes to the urethra and urinary bladder induced by surgery were examined. For three mobility groups (low, intermediate and high urethral mobility before surgery) we compared the changes induced by the operation and the typical position and mobility of the tape. The position of the urethra at rest was not influenced by surgery. The operation significantly decreased the mobility of all parts of the urethra during Valsalva. The absolute changes of the vector of the urethral movement differed according to the mobility group (average decrease, 6 mm; decrease for women with low, intermediate and high mobility, respectively, 2-3 mm, 4-6 mm and 9 mm). The change in relative mobility was the same in all groups. The operation decreased funneling (width and depth) during maximal Valsalva. After surgery there was an increase in the thickness of the bladder wall (by 0.64 and 0.73 mm, respectively, at the anterior part and trigone). A successful TVT procedure did not influence the position of the urethra at rest but significantly decreased the mobility of the urethra during Valsalva and also decreased funneling at maximal Valsalva.

Sonographic findings in acute urinary retention secondary to retroverted gravid uterus: pathophysiology and preventive measures.

To explore the pathophysiology of acute urinary retention in women with a retroverted gravid uterus and to suggest measures to prevent its recurrence. In five women with a retroverted gravid uterus and acute urinary retention necessitating catheterization, the morphology of the genitourinary system was assessed by using transabdominal, transvaginal and introital sonography. In the supine resting position, the cervix was displaced superiorly and anteriorly by the impacted and retroverted uterus so that it compressed the lower bladder, leading to obstruction of the internal urethral orifice. The upper bladder extended superiorly and overlay the uterus. During straining, urethral motion was not limited and there was an average rotational angle of the bladder neck of 32 degrees, ranging from 21 degrees to 44 degrees. Increasing abdominal pressure further compressed the lower bladder. Measures suggested to the women for the prevention of urinary retention included limiting fluid intake before sleep, changing from the supine to the prone position before getting up and avoiding a Valsalva maneuver but performing a Credé maneuver during voiding. In all except one case these measures successfully prevented recurrence. Acute urinary retention secondary to a retroverted gravid uterus is caused by a displaced cervix compressing the lower bladder and interfering with drainage to the urethra. The urethra itself is not compressed or distorted. Understanding the pathophysiology of the lower urinary tract may allow maneuvers which prevent acute urinary retention.

Changes in vesical neck mobility following vaginal delivery

To assess changes in urethral movement during the Valsalva maneuver and pelvic floor muscle contraction following vaginal delivery. In a prospective repeated-measures study, 25 primigravidas, 20 multiparas, and ten women who were to have elective cesarean delivery were examined sonographically at 36-42 weeks of pregnancy and 6-10 weeks after delivery. Vesical neck position at rest and excursion during Valsalva maneuver and maximum pelvic muscle contraction were measured with perineal ultrasound. Data about resting bladder neck position and bladder neck elevation at contraction were compared with findings in age-matched nulligravid volunteers. The bladder neck was significantly lower at rest in women after vaginal delivery than in those who had an elective cesarean delivery and in nulligravid controls. Bladder neck mobility had increased during the Valsalva maneuver in 16 of 25 primigravidas and 15 of 20 multiparas 6-10 weeks after vaginal delivery. The ability to elevate the vesical neck during pelvic muscle contraction was decreased in six of 25 primigravidas and in two of 20 multiparas 6-10 weeks after birth. Two women, one primigravid and one para 2 (with a previous elective cesarean delivery), both of whom had forceps delivery, completely lost the ability to contract voluntarily the pelvic floor muscles. Vaginal delivery alters vesical neck descent during the Valsalva maneuver, and the ability of the pelvic muscles to elevate the urethra in some women.

Cough-Induced Microtransducer Movements in the Urethra Affecting Pressure Measurements

Ratios of the amplitudes of the pressure increments in the urethra and vagina during coughing have been measured with two types of microtransducer catheters in fixed and loose positions. The data obtained from 14 urge incontinent women clearly indicate an artifactual contribution to the cough-induced urethral pressure increment measured by a semirigid microtransducer catheter attached to a withdrawal apparatus. This contribution due to urethral movement over the microtransducer catheter is negative in the proximal urethra and positive distally and accounts for the S-shaped distribution of transmission ratios along the urethra, as has been described for continent women. Transmission ratios exceeding 100 per cent were found over at least a part of the urethra. This excess proved to be present in all four versions of measurement and consequently cannot be considered as artifactual.