Risk factors for subsequent urethral atrophy in patients undergoing artificial urinary sphincter placement

Artificial urinary sphincter (AUS) device failure or revision can be due to multiple etiologies including erosion, infection, mechanical malfunction, and urethral atrophy. However, few studies have evaluated factors that predispose patients to urethral atrophy. Here, we sought to identify preoperative and perioperative risk factors associated with urethral atrophy in men undergoing primary artificial urinary sphincter (AUS) placement for stress urinary incontinence.

From 1987 to 2013, 1829 AUS procedures were performed at our institution. A total of 1068 patients underwent primary AUS placement and were the focus of our study. Multiple clinical and surgical variables were evaluated for a potential association with revision for atrophy. Those found to be associated with atrophy and relevant competing risks were further evaluated on multivariable analysis.

With a median follow-up of 4.2 years (IQR 1.3-8.1), 89 men (8.3%) had urethral atrophy requiring reoperation. Median time to revision was 4.5 years (IQR 1.9-7.6). On univariable analysis, only smaller cuff size (4.0-cm versus 4.5-cm; HR 3.1, p=0.04) was associated with an increased rate of urethral atrophy. Notably, patient age at the time of surgery (p=0.62), body mass index (0.22), and smoking status (p=1.00) were not associated with a risk of atrophy. On multivariable analysis smaller urethral cuff size remained significant (HR 2.8, 95% CI 1.1-7.1; p=0.01).

Revision surgery for urethral atrophy was performed in approximately 8% of men undergoing primary AUS placement. Utilization of a smaller AUS cuff size appears to be an independent factor associated with increased rate of urethral atrophy.