The male sling is an alternative to the artificial urinary sphincter, currently gold standard, for the treatment of post prostatectomy incontinence (PPI) (1).The artificial urinary sphincter is not suitable for all PPI patients however, there has been no high level evidence published comparing the treatment options to date. Although the male sling is now an accepted treatment option, variable success rates have been reported. The likelihood of success is not well understood and the predictors of outcome poorly documented (2). 
Our aims were twofold, firstly to review the success rates of the male sling across two supra-regional urology centres. Secondly to review the pre-operative parameters for success that might facilitate patient selection.

All men with post prostatectomy incontinence across two supra-regional urology centres had data collected in a prospective database. Data included previous intervention, radiotherapy, 24h pad weights and number of pads used. Pre-operative urodynamic parameters including evidence of detrusor overactivity, compliance, bladder capacity and retrograde leak point pressure were also collected. Statistical analysis was conducted comparing pre-operative parameters of post-operatively dry (1 or less pad for reassurance) versus post-operatively wet (1 or more pads per day) cohorts.

100 men were treated with the Advance male sling system between 2012 and 2018.  Mean patient age was 67 years (range 47 to 88). Mean follow up time was 66 weeks (range 3 weeks to 5.5 years).  
73 patients were cured of their incontinence (1 or less pads for reassurance), of which 46% did not use any pads postoperatively. 27 patients remained significantly wet (more than 1 pad per day). No patients suffered the equivalent of or greater than a Clavien-Dindo grade 3 complication.
The table shows preoperative parameters in those who were dry versus those who remained wet. Differences were assessed using paired T-tests, Mann-Whitney U Test and Fisher's Exact Test as appropriate. A p<0.05 is considered significant.
Patients who pre-operatively had a higher pad use, demonstrated detrusor activity or reduced bladder capacity on preoperative urodynamics were associated with poorer outcomes.

Within our population the majority of operations were successful, with 73% postoperatively dry. The procedure was not associated with any high grade complications. A minority of our wet patients went on to have further incontinence procedures (6 artificial urinary sphincters and 3 male bulking). Overall, the male sling is a safe treatment options for those suffering with PPI.
The pre-operative parameters that were linked to wetter postoperative outcomes were the presence of detrusor overactivity, reduced bladder capacity and increased number of pads used per day. These parameters can be identified using relatively non-invasive methods, ie video urodynamics, and treatment given to improve surgical outcomes. Those with detrusor overactivity found pre-operatively were treated with anticholinergics. The presence of detrusor overactivity should not exclude patients from the male sling as a treatment option, but should be counselled with caution.
Number of pads used per day pre-operatively, alongside 24 hour pad weight, is an indication of the severity of urinary incontinence. In our cohort, those who had more severe urinary incontinence pre-operatively were more likely to remain wet post-operatively. This is consistent with published data. Further comparisons should be made between treatment options to consider which have better outcomes for severe incontinence.
The number of pre-operative pads could be considered patient dependent and variable. Theretrograde leak point pressure, has been considered a surrogate marker of sphincter strength. 
In our patient population; having previous radiotherapy, reduced bladder compliance and retrograde leak point pressure were not associated with having worse post-operative outcomes.

Male sling was a successful treatment in the majority of patients irrespective of pre-operative parameters. The only predictors of poor outcome to statistical significance in this group were the number of pads, presence of detrusor overactivity and a smaller bladder capacity on preoperative videourodynamics. Patients should be carefully counselled but not be excluded from male sling treatment on pre-operative parameters alone.

Baus.org.uk. (2018). [online] Available at: http://www.baus.org.uk/_userfiles/pages/files/Patients/Leaflets/Synthetic sling male.pdf [Accessed 6 Oct. 2018].
Constable, L., Cotterill, N., Cooper, D., Glazener, C., Drake, M., Forrest, M., et al. (2018). Male synthetic sling versus artificial urinary sphincter trial for men with urodynamic stress incontinence after prostate surgery (MASTER): study protocol for a randomised controlled trial. Trials, 19(1).