MASTER: Male Synthetic Sling versus Artificial Urinary Sphincter After Prostate Surgery
MASTER was an open-label, multicenter noninferiority randomized trial comparing a fixed transobturator synthetic sling with an artificial urinary sphincter (AUS) in 380 men with bothersome urodynamic stress incontinence after prostate surgery. The sling met the prespecified margin for strict patient-reported continence at 12 months, while incontinence symptom scores favored the AUS.[1]
- Design and population
- Multicenter, open-label noninferiority randomized trial. Men at 27 UK centers with bothersome urodynamic stress urinary incontinence after prostate surgery, despite conservative treatment, who chose surgery and could receive either implant.
- Arms
- Fixed transobturator synthetic male sling versus artificial urinary sphincter
- Report and follow-up
- 2021 · Primary continence assessment at 12 months after randomization; adverse events through 12 months after surgery
| Endpoint | Results | Effect | Finding |
|---|---|---|---|
| 12-month continent proportion; adjusted risk difference in percentage points (sling minus AUS) | 20/154 (13.0%) continent; 134/154 (87.0%) incontinent vs 25/158 (15.8%) continent; 133/158 (84.2%) incontinent | difference -3.6; CI -11.6–4.6; P 0.003 (noninferiority) | Met |
Harms: Inpatient serious adverse events: 6 events in 6/180 operated men vs 13 events in 11/173 operated men; Catheter problems during admission: 45/180 (25.0%) vs 13/173 (7.5%)
ISRCTN49212975 · Report DOI
Design
At 27 UK centers, men could enter after choosing surgery for persistent stress leakage despite conservative treatment. Radical prostatectomy and transurethral resection of the prostate were eligible antecedent operations. Previous sling or AUS implantation, unresolved bladder-neck contracture or urethral stricture, and inadequate dexterity to operate an AUS excluded enrollment. Randomization was minimized by prostate operation, prior radiotherapy, and center. Surgeons were competent in AUS placement; less experienced sling surgeons were mentored, and participating centers used agreed operative guidance.[1]
The primary endpoint was any reported urine loss at 12 months on either the frequency or amount item of the ICIQ-UI SF. Thus continence required responses of “never” and “none,” a stricter endpoint than pad freedom or patient-perceived improvement. The prespecified noninferiority margin was a 15-percentage-point disadvantage in the sling arm's continent proportion. Analysis retained randomized assignment and adjusted for baseline pad weight, prior radiotherapy, and center.[1]
Results
At 12 months, 20/154 (13.0%) sling-assigned men and 25/158 (15.8%) AUS-assigned men met the strict continence definition; equivalently, 134/154 (87.0%) and 133/158 (84.2%) reported some leakage. The adjusted continence risk difference, sling minus AUS, was −3.6 percentage points (95% CI −11.6 to 4.6; noninferiority P = 0.003), clearing the −15-point margin.[1]
ICIQ-UI SF symptom scores fell from 16.1 to 8.7 in the sling group and from 16.4 to 7.5 in the AUS group at 12 months (adjusted mean difference 1.4 points, 95% CI 0.2–2.6; P = 0.02, lower is better).[1] Completely or fairly satisfied were 104/144 (72.2%) and 125/138 (90.6%), respectively.[1] The full trial report estimated the same 12-month symptom comparison at 1.30 points (95% CI 0.11–2.49; P = 0.032).[1][2]
The full report recorded strict continence at 24 months in 21/140 (15.0%) sling-assigned men and 22/148 (14.9%) AUS-assigned men. Its adjusted continence risk difference was −0.6 percentage points (95% CI −9.2 to 8.0; noninferiority P = 0.001). A less-strict definition allowing a small amount of leakage once weekly or less yielded 44/140 (31.4%) versus 51/148 (34.5%); its interval crossed the noninferiority margin (adjusted difference −4.0 points, 95% CI −16.7 to 8.8; noninferiority P = 0.045).[2]
The subsequent journal update reported 24-month ICIQ-UI SF scores of 7.9 versus 7.1 (adjusted mean difference 1.4 points, 95% CI 0.2–2.6; P = 0.024), again favoring AUS.[3] The full trial report's more precise estimate was 1.42 points (95% CI 0.18–2.65).[2] Its NHS economic base case estimated £5,513 in the sling group versus £8,010 in the AUS group, an adjusted difference of −£2,497 (95% CI −£3,167 to −£1,875); the estimated quality-adjusted life-year difference was −0.006 (95% CI −0.06 to 0.054).[2][3]
Surgery and treatment delivery
The protocol used a nonadjustable polypropylene sling beneath the urethra, with arms passed bilaterally through the obturator foramina. AUS implantation placed a urethral cuff, scrotal control pump, and pressure-regulating balloon; the cuff remained deactivated for 4–6 weeks before clinic activation. The full report counted surgery in 180/190 sling-assigned and 175/190 AUS-assigned men, including crossovers: 2 sling-assigned men received AUS and 9 AUS-assigned men received a sling. Mean operative time was 101 versus 128 minutes.[2]
Through 24 months, device replacement or removal occurred in 20/180 (11.1%) operated sling-assigned men versus 4/175 (2.3%) operated AUS-assigned men. In the sling arm, 18 received an AUS and 2 received another sling; in the AUS arm, 3 received a replacement AUS and 1 had removal without replacement.[2]
Adverse events
The full report counted inpatient serious adverse events in 8/180 (4.4%) operated sling-assigned men and 13/175 (7.4%) operated AUS-assigned men, comprising 8 and 15 events, respectively.[2] Sling events included 3 recatheterizations prolonging admission, 3 mesh erosions, and 1 urosepsis; AUS events included 3 recatheterizations, 3 infections, and 2 device erosions. One AUS recipient experienced three serious events. The earlier article had counted 6 events in 6/180 sling-assigned men and 13 events in 11/173 AUS-assigned men.[1][2]
Postoperative catheterization was required in 28/180 (15.6%) sling-assigned men versus 8/175 (4.6%) AUS-assigned men; catheterization beyond 24 hours occurred in 20/180 (11.1%) and 6/175 (3.4%). In cumulative patient questionnaires through 24 months, pain at the surgical site was reported by 56/190 (29.5%) versus 44/190 (23.2%), and urinary tract infection by 23/190 (12.1%) versus 20/190 (10.5%).[2]
Limitations
The primary measure counted any leakage and was available for 312/380 randomized men at 12 months; patient-reported pad use, symptom burden, satisfaction, and repeat surgery describe other aspects of the result.[1] Treatment was unblinded, and crossover occurred in both directions. The original report's baseline-severity subgroup estimates were uncertain, so the randomized comparison did not establish a separate effect in men with heavier baseline leakage. The trial tested fixed transobturator slings, with surgeon mentorship, against AUS implantation.[1][2]
In conversation
- Parallel to AUSCO (2025). MASTER randomized a male sling against the artificial urinary sphincter; AUSCO followed sphincter outcomes in a single arm.
Guidelines and approvals
- EAU, 2026, Non-neurogenic Male LUTS. Offer nonadjustable transobturator slings to men with mild-to-moderate post-prostatectomy stress urinary incontinence . Inform men that severe incontinence, prior pelvic radiotherapy, or transurethral surgery may worsen the outcome of nonadjustable male sling surgery . Offer AUS to men with moderate-to-severe stress urinary incontinence .[4]
Report history
| Published | Report | Cutoff | Headline results | Citation |
|---|---|---|---|---|
| 2021-02-04 | 12-month primary report · primary | — | 12-month continent proportion; adjusted risk difference in percentage points (sling minus AUS): 20/154 (13.0%) continent; 134/154 (87.0%) incontinent vs 25/158 (15.8%) continent; 133/158 (84.2%) incontinent; difference -3.6; CI -11.6–4.6; P 0.003 (noninferiority) Met 12-month score; adjusted mean difference in points (sling minus AUS): 8.7 (baseline 16.1) vs 7.5 (baseline 16.4); difference 1.4; CI 0.2–2.6; P 0.02 12-month completely or fairly satisfied proportion; risk difference in percentage points (sling minus AUS): 104/144 (72.2%) vs 125/138 (90.6%); difference -18.4; CI -27.2–-9.6; P <0.001 | Abrams P, Constable LD, Cooper D, et al. Outcomes of a Noninferiority Randomised Controlled Trial of Surgery for Men with Urodynamic Stress Incontinence After Prostate Surgery (MASTER). *Eur Urol.* 2021;79(6):812-823. doi:10.1016/j.eururo.2021.01.024 DOI |
| 2022 | Full trial and economic report · updated | — | 12-month score; adjusted mean difference in points (sling minus AUS): 8.7 (baseline 16.1) vs 7.5 (baseline 16.4); difference 1.3; CI 0.11–2.49; P 0.032 Descriptive 24-month continent proportion; adjusted risk difference in percentage points (sling minus AUS): 21/140 (15.0%) vs 22/148 (14.9%); difference -0.6; CI -9.2–8; P 0.001 (noninferiority) Met 24-month continent proportion; adjusted risk difference in percentage points (sling minus AUS): 44/140 (31.4%) vs 51/148 (34.5%); difference -4; CI -16.7–8.8; P 0.045 (noninferiority) Not met 24-month score; adjusted mean difference in points (sling minus AUS): 7.9 (131 respondents) vs 7.1 (139 respondents); difference 1.42; CI 0.18–2.65; P 0.024 24-month mean cost; adjusted mean difference in pounds sterling (sling minus AUS): £5,513 vs £8,010; difference -2497; CI -3167–-1875 | Constable L, Abrams P, Cooper D, et al. Synthetic sling or artificial urinary sphincter for men with urodynamic stress incontinence after prostate surgery: the MASTER non-inferiority RCT. *Health Technol Assess.* 2022;26(36):1-152. doi:10.3310/TBFZ0277 DOI |
| 2026-08-26 | 24-month journal update · updated | — | 24-month adjusted continence risk difference (sling minus AUS): The abstract reports the adjusted difference but not arm-specific counts; the full 2022 HTA Table 7 supplies 21/140 versus 22/148.; difference -0.006; CI -0.092–0.08; P 0.001 (noninferiority) 24-month score; adjusted mean difference in points (sling minus AUS): 7.9 (baseline 16.1) vs 7.1 (baseline 16.4); difference 1.4; CI 0.2–2.6; P 0.024 | Constable L, Drake MJ, Cooper D, et al. The 24-mo Outcomes from the Noninferiority Randomised Controlled Trial of Surgery for Men with Urodynamic Stress Incontinence After Prostate Surgery (MASTER). *Eur Urol Focus.* 2026;12(4):636-643. doi:10.1016/j.euf.2026.07.012 DOI |
References
1. Abrams P, Constable LD, Cooper D, et al. "Outcomes of a Noninferiority Randomised Controlled Trial of Surgery for Men with Urodynamic Stress Incontinence After Prostate Surgery (MASTER)." Eur Urol. 2021;79(6):812-823. doi:10.1016/j.eururo.2021.01.024
2. Constable L, Abrams P, Cooper D, et al. "Synthetic sling or artificial urinary sphincter for men with urodynamic stress incontinence after prostate surgery: the MASTER non-inferiority RCT." Health Technol Assess. 2022;26(36):1-152. doi:10.3310/TBFZ0277
3. Constable L, Drake MJ, Cooper D, et al. "The 24-mo Outcomes from the Noninferiority Randomised Controlled Trial of Surgery for Men with Urodynamic Stress Incontinence After Prostate Surgery (MASTER)." Eur Urol Focus. 2026;12(4):636-643. doi:10.1016/j.euf.2026.07.012
4. Cornu JN, Elterman D, Hashim H, et al. EAU Guidelines on Non-Neurogenic Male Lower Urinary Tract Symptoms (LUTS). European Association of Urology; 2026. §5.6.5, male slings and artificial urinary sphincter.