To compare ultrasonographic standards by two-dimensional perineal ultrasonography in men in the pre and postoperative periods of transobturator sling procedure in the treatment of urinary incontinence after radical prostatectomy.

It is a prospective, multicenter (2 centers), non-randomized, uncontrolled study. The study involved 31 patients from the outpatient clinic of these two centers, with adequate indication for examination and surgery. These patients were selected according to the inclusion and exclusion criteria, being composed only of incontinent patients and divided into two different groups: Group 1 - Mild / moderate incontinence (Pad test <400g / 24h); Group 2- Severe incontinence (Pad test> 400g / 24h).[1] These patients were submitted to transobturator sling procedure with DynaMesh®-PRM in the period from August  2014 to August  2018.
	   All of them presented negative uroculture, 24h Pad test, urodynamic evaluation, ICIQ-SF quality of life questionnaire and urethrocystoscopy (if necessary). Perineal Ultrasonography was performed in the preoperative period of 21 patients and in the period of three to six months postoperatively of transobturator sling of 30 patients. The examination was performed with the patient in the supine position, with the legs slightly abducted, similar to the Litotomy. The transducer was positioned with slight pressure in the perineal region (between the scrotum and the anus), in sagittal orientation, to obtain images of the pubic symphysis, bladder, bladder neck and urethra.[2]
           During preoperative and postoperative examination, hypermobility of the proximal urethra, as well as voluntary contraction of the pelvic floor, were evaluated during Valsalva maneuver, perineal contraction and rest. We also evaluated the distance between de the urethra from pubis and the urethral angle. Positioning of the bladder neck was performed at rest, during Valsalva maneuver and during contraction of the pelvic floor. The measurements were made by means of xy coordinate system, as the reference point the pubis. The X axis was drawn by a line at the upper border of the pubic symphysis. The Y axis was drawn perpendicular to the X axis at the upper border of the pubic symphysis. For exact positioning of the bladder neck, the most proximal and superior point of the urethral wall was used, in the immediate vicinity of the transition with the bladder. The movement of the bladder neck was calculated by the following formula: √ (x2 - x1) ² + (y1- y2) ², where x1 and y1 represent the coordinates at rest.[3]  (FIGURE 1)
            After data collection, ultrasonographic patterns were compared in men in the preoperative and postoperative periods of the transobturator sling in 21 patients and in the postoperative period in 30 patients. The significance criterion adopted was the level of 5%. Statistical analysis was performed using statistical software SAS® System, version 6.11 (SAS Institute, Inc., Cary, North Carolina).

In this study, the group with mild / moderate incontinence presented a clinical improvement (> 50%) significantly higher than the group with severe incontinence after male sling surgery (81,3% vs 42,9% p = 0.035). There was no statistical difference in relation to the pressure loss observed in the preoperative urodynamic evaluation between the two groups (p = 0.12).
            There was no statistical difference in all the ultrasound parameters evaluated from preoperative to postoperative in the twenty one patients. Therefore, we chose to present the results of the thirty patients obtained postoperatively for the final analysis of the results.
            The incontinent group that evolved with clinical improvement > 50% after the male sling procedure showed the displacement of the posterior portion of the bladder neck during the contraction significantly greater than the incontinent group with clinical improvement <50% (p = 0.024). In the postoperative period, the ICIQ-SF score of the group with clinical improvement > 50% was significantly lower than the group with improvement < 50% (7 vs15 p=0.001). (TABLE 1)

Urodynamic evaluation did not prove to be an adequate tool for stratification of groups, since there was no statistical difference in loss pressure between the two groups. In addition, male sling did not promote a significant change in the ultrasound parameters from preoperative to postoperative in the twenty one patients evaluated. The most important finding of this study was the significant ultrasound difference in the posterior displacement of the bladder neck during the contraction in patients who presented improvement (> 50%) in relation to those who presented improvement (<50%) p = 0.024. This latter data may support a possible use of perineal ultrasonography in the evaluation and selection of patients to undergo male sling. This lower mobility of the bladder neck in the incontinent group, especially in the most severe group, may be related to the degree of fibrosis of the periurethral tissues and partial denervation of the pelvic floor musculature during radical prostatectomy. These ultrasound findings are well-connected and may explain the surgical results of Fischer's study.[1']

Parameters of perineal ultrasonography in men are still not well established and the results obtained in our work may help to guide future studies in this area. Therefore, two-dimensional perineal ultrasonography provides more details on the diagnosis of male urinary incontinence after radical prostatectomy, and may help reduce treatment failure and define which method is most appropriate for each patient. In this way, perineal ultrasonography could help identify patients with severe urinary incontinence who would benefit from male sling. It could also be used as a visual aid for biofeedback by teaching correct muscle contraction of the pelvic floor in men with urinary incontinence after radical prostatectomy.

FISCHER MC et al. The male perineal sling: assessment and prediction of outcome. J Urol. 2007 Apr;177(4):1414-8.
THOMPSON JA et al. Assessment of pelvic floor movement using transabdominal and transperineal ultrasound. International Urogynecology Journal, 2005, 16; 285-92.
HERMANNS RK et al. Two and three/four dimensional perineal ultrasonography in men with urinary incontinence after radical prostatectomy. Btritish Journal of Urology, 2011, doi: 10.1111/j.1464-410X2011.10191.x