HOW ACCURATE ARE WE IN URETHRAL MOBILITY ASSESSMENT? - SUBJECTIVE VS OBJECTIVE ASSESSMENT
SVABIK, P. HUBKA, J. MASATA, A. MARTAN;
Ob/Gyn, First Faculty of Med., Charles Univ. in Prague, Gen. Univ. Hosp., Prague, Czech Republic.
Introduction: Knowledge of the mobility of urethra plays an important role in patients with stress urinary incontinence and its assessment is an important element of standard urogynecological examination. It has been assumed that increased mobility is associated with higher likelihood of successful treatment. There is an arbitrary defined cut-off for hypermobile urethra - descend of more than 15 mm during Valsalva manoeuvre or 30-degree rotation or more. Clinically, we categorize mobility of the urethra as hypermobile or low mobile urethra, with the situation in-between as mobile urethras. But how accurate are we in our subjective assessment?
Objective: We have provided retrospective analysis of mobility of the urethra assessed during clinical examination by transperineal ultrasound (US) with subjective scoring of the mobility (low, norm, hyper) and compared this assessment with detailed measurement of descent and rotation of the urethra.
Methods: This is a retrospective analysis of women diagnosed with urodynamic stress incontinence (USI) and treated with tension free vaginal slings during the period 01/2009 - 10/2016. For each patient, there was available urethra mobility data at the time of preoperative assessment (low-, norm- or hyper- mobile) and we compared this assessment with measured parameters of bladder neck) (BN) mobility analysed at a later date from stored 4D US volumes. We also measured dorsocaudal movement of the BN (H -distance). This is the distance of the BN from the horizontal line at the level of lower margin of the symphysis and we compared the position at rest and at Valsalva. Secondly, we measured rotation of the urethra using the gama angle - angle between the line connecting BN to lower margin of symphysis and axis of symphysis at rest and during the Valsalva manoeuvre. Mobility of the BN is the difference between the rest and Valsalva position. We compared the objective parameters of mobility with subjective assessment.
Results: 427 patients were treated during the analysed period, 394 had available stored 4D US volume for analysis. Mean age 56.5 years (min 29 - max 87, SD 7.9), mean BMI 27.4 (min 18.3 - max 39.6, SD 7.9), mean parity 2.14. Mean descent of the bladder neck was 11.8 mm (min -1; max 37; SD 6.9) Mean rotation of the bladder neck was 38.8 degree (min -5; max 118, SD 20.0). We provided correlation of mobility using both parameters - H-distance, Gama angle (graph). Comparisons of subjective mobility assessment and objective parameters are shown in table and boxplots.
Conclusions: According to our data and relevant analysis, it is obvious that cut-offs for hypermobility regarding the descend of 15 mm and 30-degree rotation do not describe the same situation. The graph demonstrates the distinct correlation of both parameters. Despite statistically significant differences confirming capability of subjective mobility assessment, box plots demonstrate that our initial subjective assessment was not accurate. While this may prove to be clinically irrelevant, it nonetheless, certainly seems to be important to use objective parameters for mobility in cases of mobility group assessments.