Assessing urethral mobility similarly involves simple observation while the patient is in a supine lithotomy position and straining. A Q-tip test or the Pelvic Organ Prolapse Quantification (POP-Q) system may be used, but visualization and palpation also are completely acceptable.
Just as the absence of urethral mobility is a red flag, so is prolapse beyond the hymen. This patient could potentially have urethral kinking, which can mask the severity of SUI or be a source of retention. Either finding the absence of urethral mobility or the presence of POP beyond the hymen moves the case from the uncomplicated to complicated category and signals the need for further evaluation with urodynamics or other tests.
These and other findings for uncomplicated versus complicated SUI are outlined in a committee opinion issued recently by the American College of Obstetricians and Gynecologists and the American Urogynecologic Society (Committee Opinion No. 603, Obstet .Gynecol. 2014;123:1403-7).
As the ACOG-AUGS recommendations point out, urinalysis is part of the minimum work-up for stress incontinence. Measurement of postvoid residual urine volume also becomes important when midurethral sling surgery is being contemplated for uncomplicated SUI. A normal volume rules out potential bladder-emptying abnormalities and provides final assurance that the patient is a good candidate for surgical repair.
Recent research on urodynamics
Evidence that a simple office-based incontinence evaluation without preoperative urodynamic testing is appropriate for uncomplicated predominant SUI comes largely from two recent randomized noninferiority trials.
One of these trials – a study from the Urinary Incontinence Treatment Network in the United States, known as the VALUE trial – randomized 630 women with uncomplicated SUI to pretreatment work-up with or without urodynamics. Treatment success at 12 months was similar for the two groups (approximately 77%).
This finding, the authors wrote, suggests that for women with uncomplicated SUI, a “basic office evaluation” (i.e., a positive provocative stress test, a normal postvoiding residual volume, an assessment or urethral mobility, and a negative urinalysis) is a “sufficient preoperative work-up” (N. Engl. J. Med. 2012;366:1987-97).
The diagnosis of SUI as made by office evaluation was confirmed in 97% of women who underwent urodynamic testing, and while there were some adjustments in diagnosis after urodynamics, there were no major changes in treatment decision making after the testing. Approximately 93% of women in both groups underwent midurethral sling surgery.
The second trial, a Dutch study, focused on women who had already undergone urodynamic testing and been shown to have discordant findings on urodynamics and their history and clinical exam. The women – all of whom had uncomplicated predominant SUI – were randomized to undergo immediate midurethral sling surgery or receive individually tailored treatment (including sling surgery, behavioral and physical therapy, pessary, and anticholinergics).
At 1 year, there was no clinically significant difference between the two groups in patients’ assessment of their symptoms as measured by the UDI. The authors concluded that “an immediate midurethral sling operation is not inferior to individually tailored treatment based on urodynamic findings” and that “urodynamics should no longer be advised routinely before primary surgery in these patients” (Obstet. Gynecol. 2013;121:999-1008).
When urge incontinence is involved
Urodynamic testing was never believed to be perfect, but these and other studies have highlighted its imperfections. Urodynamics creates an artificial condition in the bladder, in effect, and some of the findings will involve artifact. A systematic review of studies that compared diagnoses based on symptoms with diagnoses after urodynamic investigation was interesting in this regard; while the review did not assess impact on treatment, it showed that there is poor agreement between clinical symptoms and urodynamic-based diagnoses (Neurourol. Urodyn. 2011;30:495-502).
Certainly, women with complicated SUI – as well as women who have recurrent SUI after a prior surgical intervention – require further assessment, which likely includes multichannel urodynamic testing.
Urodynamics also can play a useful role in decision making and counseling for some patients whose incontinence is predominately SUI, but is believed to involve some degree of urinary urgency. Patients with mixed urinary incontinence fare worse after midurethral sling procedures compared with patients who have SUI alone, and I counsel my patients accordingly, emphasizing that the sling will not address aspects of their incontinence related to urgency. When I sense that a patient may have unreasonably high expectations for surgery, urodynamic testing can provide some perspective on possible postoperative outcomes.
Treatment for UI or overactive bladder often may be initiated after simple office-based evaluation, just as with SUI. The goal, similarly, is to discern relatively uncomplicated or straightforward cases from complicated ones. Urologic, medical, and neurologic histories should be obtained, for instance, and retention issues (which can aggravate UI) should be ruled out through the measurement of postvoid residual urine volume.