Risk factors for failure of repeat midurethral sling surgery for recurrent or persistent stress urinary incontinence

INTRODUCTION AND HYPOTHESIS: To study the outcomes following repeat midurethral sling (MUS) surgery in patients with persistent or recurrent stress urinary incontinence after failure of primary MUS surgery and risk factors for surgical failure.

METHODS: The medical records of 24 patients who underwent repeat MUS surgery at a single tertiary center from January 2004 to February 2014 were reviewed. The types of MUS used for the repeat surgey were transobturator, retropubic and single incision slings. Objective cure was defined as no demonstrable involuntary leakage of urine during increased abdominal pressure in the absence of a detrusor contraction observed during filling cystometry, and subjective cure was defined as a negative response to Urogenital Distress Inventory six (UDI-6) question 3 during follow-up between 6 months and 1 year postoperatively. The change in the inclination angle between the urethra and pubic axis was measured with introital ultrasonography and the cotton swab test performed.

RESULTS: The objective and subjective cure rates were 79.2 % and 75 %, respectively. There were no differences in demographics between the patients with failure of surgery and those with successful surgery. Significant independent risk factors for failure of repeat MUS surgery were a change in cotton swab angle at rest and straining of <30° (OR 4.6, 95 % CI 2.5 - 7.9°), a change in inclination angle of <30° (OR 4.6, 95 % CI 2.5 - 7.9°), intrinsic sphincter deficiency (OR 3.4, 95 % CI 1.8 - 6.1) and a mean urethral closure pressure of <60 cm H2O (OR 2.9, 95 % CI 1.5 - 4.5). In one patient the bladder was perforated.

CONCLUSIONS: Repeat MUS surgery is safe and has a good short-term success rate, both objectively and subjectively, with independent risk factors for failure related to bladder neck hypomobility and poor urethral function.