May 17, 2010

Holly Richter. Download image.

BIRMINGHAM, Ala. - University of Alabama at Birmingham (UAB) researchers conducting the largest randomized, clinical-equivalence trial comparing two mid-urethral sling procedures for female urinary incontinence say the two have equal efficacy - but may present different types of complications.

The study results were presented May 17 during the American College of Obstetricians and Gynecologists 58th Annual Clinical Meeting in San Francisco and simultaneously published online by the New England Journal of Medicine. 

Urinary incontinence affects up to 50 percent of women in the United States, resulting in significant medical, social and economic burdens. Among women with urinary incontinence, 15 to 80 percent have a component of stress incontinence,in which leakage of urine occurs during physical exertion, sneezing and coughing. Four to 10 percent of these women undergo surgery to fix the disorder.

Holly E. Richter, Ph.D., M.D., James Marion Sims Endowed Chair in Obstetrics and Gynecology and director of the Division of Women's Pelvic Medicine and Reconstructive Surgery at UAB, is the lead author of the study detailing the findings of the Trial Of Mid-Urethral Slings (TOMUS) trial. Richter said that both the transobturator and retropubic procedures insert a mesh sling or "hammock" to support the midurethra so that urine does not leak. These procedures have been approved by the FDA and have been shown to be safe and successful in treating stress urinary incontinence.

"We did not know before this study is if one approach results in better efficacy than the other," Richter said. "This study has helped answer that question and should help provide outcome and safety information to pelvic surgeons and their patients so that they can make better-informed treatment decisions."

Some 597 women were randomized in the study, and 565 or 94.6 percent completed the 12-month primary outcome-assessment time-point; 291 of 298 randomized subjects in the retropubic arm and 292 of 299 randomized subjects in the transobturator arm received the assigned surgery. Data was collected pre-operatively, two weeks, six weeks and six and 12 months post-operatively by interview and clinical examination.

Richter and colleagues founds that objective cure rates - defined as measured as a negative provocative stress test,a negative 24-hour pad test and no retreatment for stress incontinence - after retropubic or transobturator slings were placed were 80.8 percent and 77.7 percent, respectively. The difference in efficacy rates including confidence intervals met the predetermined criteria for equivalence. Subjective cure rates - defined as self-reporting stress-type urinary incontinence symptoms, no leakage on a three-day voiding diary and no retreatment (behavioral, pharmacologic or surgical) for stress incontinence - were 62.2 percent and 55.8 percent, respectively. The efficacy rates were similar, but with confidence intervals, did not meet the predetermined criteria for equivalence.

The nature of complications differed between the procedures. Median estimated blood loss and operative time during the sling portion of the procedure were modest, but significantly higher in the retropubic compared to the transobturator groups. Bladder perforations requiring surgical intervention were uncommon but occurred exclusively in the retropubic arm; women in this arm were also more likely to experience post-operative urinary-tract infections. More vaginal perforations occurred in the transobturator arm. The frequency of neurologic symptoms was also higher in the transobturator compared with the retropubic group; weakness in the upper leg was the most common neurologic symptom.

Richter said it is also important to note that there was no difference in rates of satisfaction and impact on quality-of-life outcomes.

"Now we have better information to present to patients as to which procedure would benefit them most," she said. "Differential complications associated with each procedure should be discussed with patients considering surgical treatment for incontinence."

About the UAB Division of Women's Pelvic Medicine and Reconstructive Surgery

The physicians in the UAB Division of Women's Pelvic Medicine and Reconstructive Surgery provide professional and sensitive care for women with incontinence and pelvic-floor disorders. Patients in the division are provided with a variety of highly effective, non-surgical approaches to incontinence, including medications, behavioral therapies and support devices. For women needing surgery, the latest minimally invasive techniques usually allow women to go home the same day and recover quickly. Women will find revolutionary new options available, many of which were researched and developed at UAB.