Complications of mid urethral slings: important outcomes for future clinical trials.

PURPOSE Mid urethral slings are becoming the first line surgical treatment for stress urinary incontinence in women. We reviewed the complications of mid urethral sling placement and their potential pathophysiology. MATERIALS AND METHODS We conducted a literature search on MEDLINE from 1995 to 2007 using the key words sling, complications, mid-urethral slings, transvaginal tape, transobturator tape, trials, pathophysiology and complications. The Cochrane database was also searched. The results were summarized according to the type of mid urethral slings reported. RESULTS There were 928 MEDLINE citations for sling and complications, 279 for sling and complications and bladder, and 68 for sling and complications and voiding dysfunction. The reported complication rates ranged from 4.3% to 75.1% for retropubic and 10.5% to 31.3% for transobturator mid urethral slings. Complications included bladder perforation, hemorrhage, bowel injury, vaginal extrusion, de novo urgency and urge incontinence, urinary tract infections and voiding dysfunction. Retropubic mid urethral slings led to a higher occurrence of complications such as bladder perforation and hematoma. In addition, the retropubic approach resulted in serious complications such as bowel injury, major vascular injury and death. Groin pain was more common after the transobturator approach. Experimental studies indicated that the potential mechanisms for sling complications may include vaginal dissection, denervation injury and bladder remodeling. CONCLUSIONS Mid urethral slings result in bothersome complications which should not be minimized. Awareness of these complications should encourage improvements in patient counseling as well as further investigation of the underlying mechanisms. Decreasing complications should be considered an important outcome for future clinical studies of mid urethral slings.