Post-prostatectomy incontinence (PPI) has an important negative impact on QoL. The most frequently used surgical treatment options are artificial urinary sphincter (AUS) implant and male sling surgery. When patients are given the choice, they opt for sling surgery versus AUS,  even against physicians recommendation [1]. Advance® and Advance XP® male slings are currently the most used and best-studied devices. The outcome is mostly reported in non-irradiated patients with mild to moderate PPI. Data on other patient profiles are scarce.
The aim of this study was to report our long term real-life experience in a large cohort of patients. This dataset also includes non-ideal candidates after radiotherapy and previous stricture treatments.

All consecutive patients that underwent male sling implant in our department and had a minimum of 2 documented follow up visits were included in this retrospective analysis. Between January 2007 and March 2011, patients underwent Advance® sling implant, and from March 2011 onwards, Advance XP® implant. All patients were implanted by one of two experienced surgeons.
Data were extracted from the electronic patient file system in June 2018. Demographics, preoperative SUI grade, presumed risk factors for failure or complications, operative characteristics, functional outcome and postoperative complications were recorded.

Preoperative incontinence grade was categorized as mild (≤2pads), moderate (3-4 pads) or severe (≥5 pads).
We categorized patients preoperatively as “index patients” when they had mild to moderate urine loss and when they did not have any history of pelvic irradiation, previous incontinence surgery or previous stricture treatment.

Postoperatively, patients were considered “strictly dry” when using 0 pad/24 hours, and “social continent” when using 1 pad/24 hour. Patients using ≥2 pads/24 hours were considered failures. To compare with previously published series, we also documented a 50% improvement in pad use. 
When a transurethral catheterization was performed after initial catheter removal on the first postoperative day, patients were categorized as having increased post-void residual (coded as “PVR”).

We statistically analyzed our dataset for “strictly dry rate”, “social continence rate” as efficacy parameters and for “PVR” as a safety parameter. Summary statistics are presented as means and standard deviation (SD)/medians and interquartile range (IQR) for continuous variables and as frequencies and percentages for categorical variables. The Kaplan-Meier method was used for estimating the social continence rate, or strictly dry rate over time.
Logistic regression models were used to test the prognostic value of characteristics on PVR. Results are presented as odds ratios (OR) with 95% confidence intervals. Cox proportional hazards models were used to test the prognostic value of characteristics on social continence and strictly dry status. Results are presented as hazard ratios (OR) with 95% confidence intervals. Multivariable models were constructed for all three outcome variables. A forward stepwise model selection procedure was followed, assuming a 5% and a 10% significance level for variables to enter or leave the model, respectively. All tests are two-sided, a 5% significance level is assumed for all tests. Analyses have been performed using SAS software (version 9.4 of the SAS System for Windows).

216 consecutive patients underwent male sling surgery in our department. Between January 2007 and March 2011, 67 patients underwent Advance® implant and from March 2011 onwards, 149 underwent Advance XP® implant. Mean age at implant was 67±8 years. Median follow up was 11 (IQR: 3; 24) months.

A significant number of patients had a history of pelvic irradiation 41/216 (19%) and/or previous stricture treatment 28/216 (13%). Demographic variables, urodynamic results and risk factors are listed in table 1.

In the total group of patients undergoing sling surgery, 151/208 (73%) achieved social continence at last follow up visit and 88/215 (41%) were strictly dry. 162/200 (81%) patients reported a reduction in pad use of at least 50%. In the Advance® and the Advance XP® group respectively, 38/61 (62%) and 113/147 (77%) patients were socially continent and 20/67 (30%) and 68/148 (46%) strictly dry. This difference was accentuated in the non-index group with 38/62 (62%) social continence after Advance XP® versus 10/26 (39%) after Advance®.
Index patients became socially continent and strictly dry in respectively 103/121 (85%) and 64/123 (52%) cases as compared to respectively 48/87 (55%) and 24/92 (26%) in non-index patients. 
Figure 1, Kaplan Meier graph, illustrates the social continence curve by patient group index and not index.
Patients with moderate to severe preoperative incontinence obtained a ≥50% reduction in pad use in 77/99 (78%) of cases. 
Overall 26/216 (12%) of patients underwent a second treatment, 11 of whom received a second male sling and 15 an AUS implant. 
At multivariate analysis three factors were negatively correlated with social continence: previous irradiation (HR: 3.41; p<.0001), previous stricture treatment (HR: 2.43; p<.007) and presence of detrusor overactivity (DO) (HR: 2.63; p<.02). Similarly, two factors were negatively correlated with the dry state: pelvic irradiation (HR: 1.70; p=.01), the presence of urinary leakage during preoperative UDS (HR: 1.77; p<.01). On the opposite, increasing cystometric bladder capacity was positively correlated with dry status (HR: 0.86; p<.03). 

46/215 (21%) patients underwent a transurethral catheterization for high PVR. This high PVR was transient in 44/46 (96%) of patients. One patient received a suprapubic catheter, after diagnosis of an anastomotic stricture as cause of the persisting high PVR. In total, 2/215 (1%) patients underwent sling transection due to persistent high PVR after sling implant.  
6/215 (3%) of patients had a postoperative hematoma. None of them required reintervention.  
At univariate analysis, younger age was the only significant factor for increased PVR (OR 0.71; p =.05); at multivariate analysis, age was confirmed as a significant risk factor (OR 0.69; p = .03)  together with previous stricture treatment (OR 2.6; p<.05).

We report the results of male sling surgery using Advance® and Advance XP® surgery in a large, real-life cohort.
In comparison to AUS, male sling surgery offers the advantages of a low risk of significant complications, as shown by our series, with 4% lasting voiding dysfunction and 3% hematoma. The revision rate of slings is clearly lower than in AUS with 13% of patients undergoing additional surgery for persistent high PVR or failure in our series.

Our entire cohort has a high social continence rate of 73%, even with non-ideal patients included. Most of the patients underwent cystoscopy with positive reposition test prior to surgery. Although the value of this test cannot be proven from this cohort (due to lack of negative control), this might explain the high success rate, even if non-ideal patients were included. Although not statistically significant, Advance XP® seems to perform better, particularly in non-index patients. Our results also prove that a significant improvement can be obtained even when patients use more or equal than 3 pads/day (77.8%). A history of stricture, incontinence surgery or pelvic irradiation is however associated with higher failure rates.

Although our data confirm the known risk factors for failure, sling implant could be considered even in non-ideal patients, seen its low complication rates, certainly with the Advance XP system

Kumar, A., Litt, E. R., Ballert, K. N. & Nitti, V. W. Artificial Urinary Sphincter Versus Male Sling for Post-Prostatectomy Incontinence — What Do Patients Choose?? 181, 1231–1235 (2009)