Stress Incontinence Surgery Not Helped By Urodynamic Testing

Laurie Barclay, MD

April 08, 2013

For women with uncomplicated stress urinary incontinence (SUI), an immediate midurethral sling operation was not inferior to specific treatment based on urodynamic test results, according to findings of a randomized controlled trial published online April 5 in Obstetrics and Gynecology.

"This study deals with an important issue.... [I]s it necessary and useful to perform preoperative urodynamic studies for women affected by SUI?" Giovanni A. Tommaselli, MD, PhD, consultant in Obstetrics and Gynecology at the Integrated Department of Obstetrics, Gynecology, and Urology, University of Naples "Federico II" in Italy, told Medscape Medical News in an email interview. He was not involved with this study.

Between January 2009 and November 2010, Sanne Adriana Lucia van Leijsen, MD, PhD, from Radboud University Nijmegen Medical Centre, The Netherlands, and colleagues from the Dutch Urogynecology Consortium performed this diagnostic cohort study with an embedded noninferiority randomized controlled trial. At 6 academic and 24 nonacademic Dutch hospitals, they enrolled 578 women with predominant SUI eligible for surgical treatment based on clinical evaluation.

All patients had urodynamic testing, and those with discordant findings on urodynamics and clinical evaluation randomly underwent either immediate surgery or specifically tailored therapy based on urodynamics. The main study endpoint was clinical improvement on the Urogenital Distress Inventory (UDI) at 12 months after baseline. The investigators defined noninferiority as a difference in mean improvement of not more than 5 points, based on intention-to-treat analysis.

Of the 268 women (46%) with discordant findings, 126 gave informed consent for randomization and underwent immediate surgery (n = 64) or individually tailored therapy (n = 62).

After 1 year, the group receiving immediate surgery had mean improvement in UDI of 44 ± 24 points compared with 39 ± 25 points in the urodynamic testing group (difference, 5 points; 95% confidence interval, −∞ to 5). Cure and complication rates did not differ between groups.

Routine Urodynamics Unnecessary

"These findings seem to indicate that an immediate sling operation for SUI is not inferior to a treatment indicated by the results of the urodynamic studies," Dr. Tommaselli said. "Thus, routine preoperative urodynamic testing would seem not necessary and, considering the costs, the time-consuming nature of the tests, and the discomfort brought to the patients, should not be performed."

"This study has a number of strengths; in particular, it is a large, multicenter study, which allows a strong external validity," Dr. Tommaselli said. "Moreover, it has a well-designed and implemented nested randomized design, excluding women with concordance between clinical and urodynamic diagnosis and using a noninferiority design, which seems very appropriate for the issue raised by the authors."

Limitations noted by Dr. Tommaselli include the lack of blinding of the physician with respect to the allocation group and the urodynamic findings, which could have caused a bias in treatment selection.

In terms of future research, Dr. Tommaselli proposed a similar design using a blinded assessor.

"Since, in this study, women with complicated SUI (ie, with high postvoid residual and low urinary flow) were excluded for the fear of postoperative obstruction, it would interesting to test this hypothesis also on this kind of population," he concluded.

ZonMw, the Dutch Organization for Health, Research and Development, funded this study. One coauthor received an expense allowance from Ethicon Women’s Health and Urology for the follow-up of women enrolled in an observational study (Prolift+M). One coauthor received an educational grant from Medical Measurement Systems, The Netherlands. One coauthor is a member of the overactive bladder faculty of Astellas and received a travel grant from Astellas. The other authors and Dr. Tommaselli have disclosed no relevant financial relationships.

Obstet Gynecol. Published online April 5, 2013. Abstract