LAS VEGAS – In a study of patients who experienced a failed midurethral sling, urethral bulking injection was associated with a greater than threefold increased risk of failure compared with a repeat midurethral sling procedure, a retrospective analysis showed.
In addition, the diagnosis of intrinsic sphincter deficiency conferred a greater than fourfold risk of failure compared with patients without the diagnosis, regardless of which procedure was performed.
Dr. Anthony Gaddi
Those are findings from the largest cohort study to date evaluating failure of midurethral sling (MUS), and the only one to include both repeat MUS procedures and urethral bulking injections.
"This study provides important baseline data for surgeons when faced with MUS failure," Dr. Anthony Gaddi said at the annual meeting of the American Urogynecologic Society. "Prospective, randomized data with validated subjective and objective outcomes is warranted."
In an effort to compare the efficacy and safety of a repeat MUS procedure with urethral bulking injection after failed primary MUS, Dr. Gaddi and his associates performed an electronic chart review of patients from the Southern California Permanente Medical Group who underwent MUS for stress urinary incontinence (SUI) between 2008 and 2011.
The primary outcome was a measure of subjective failure, defined as a complaint of SUI, or objective failure, defined as documentation of a positive cough stress test, urodynamic stress incontinence, or reoperation for SUI, said Dr. Gaddi of the department of obstetrics and gynecology at the University of California, Irvine. Secondary outcomes included perioperative complications and adverse events.
For the 7,412 MUS procedures performed between 2008 and 2011, there were 165 repeat procedures for sling failure. Of these, 98 were repeat MUS procedures and 67 were urethral bulking injections. The mean age of patients was 58 years, their mean body mass index was 29.3 kg/m2, 65% were menopausal, and 59% were white.
Dr. Gaddi reported that there were 11 failures in the MUS group (11.2%), compared with 26 failures in the bulking group (38.8%), a difference that reached significance (P less than .01).
In multivariable logistic regression analysis, patients who underwent urethral bulking injections experienced a 3.7-fold increased risk of failure compared with those in the repeat MUS group. In addition, patients with a preoperative diagnosis of intrinsic sphincter deficiency experienced a 4.45-fold higher risk of failure compared with those who had no such deficiency, regardless of which procedure was performed.
Perioperative complications were similar between the two groups, "suggesting that both are safe options in this cohort," Dr. Gaddi said.
He acknowledged certain limitations of the study, including its retrospective design, and "difficulty standardizing our definition of failure. The low number of complications among our repeat procedures limits conclusions that can be made about safety."
Dr. Gaddi said that he had no relevant financial conflicts to disclose.