Surgical Management of Female Stress Urinary Incontinence: 22-Year Population-Level Trends - Christopher Wallis
Christopher Wallis presents the findings of a retrospective cohort study of all women in Ontario undergoing surgical management of stress incontinence between 1994 and 2016. Utilizing a time-series analysis, they were able to characterize the trends in utilization of a variety of procedures over time. He relates trend findings to that of regulatory health warnings from both the FDA and from Health Canada.
Christopher J.D. Wallis is a Urology Resident at the University of Toronto. He obtained his Doctor of Medicine from the University of British Columbia and his Doctor of Philosophy in Clinical Epidemiology & Health Care Research from the Institute of Health Policy, Management & Evaluation at the University of Toronto.
Dr. Christopher Wallis: Hello. Welcome to the presentation here regarding the surgery management of female stress urinary incontinence. I'm Christopher Wallis. I'm presenting these data on behalf of my coauthors, predominantly senior author Dr. Sender Herschorn. This is a project that was supported by an unrestricted grant for the Astellas Functional Urology Research Program, which is run out of the University of Toronto.
Most people who are reading Urotoday, are involved in this space, will understand that female stress urinary incontinence involves the involuntary leakage of urine, predominantly with a Valsalva, increasing intraabdominal pressure. This may be exertional or related to sneezing or coughing. This is a very common affliction affecting nearly one-third of Canadian women, and the majority of women who have urinary incontinence actually are stress predominant. This prevalence increases with age and so as our population ages, this is becoming an increasingly prevalent issue in Western society and predominantly for the purposes of this study, North American society.
Classical teaching regarding stress urinary incontinence revolves around multiple levels of management. The first of these is conservative and these are lifestyle changes and things like pelvic floor physiotherapy. While these can be helpful, often they're insufficient for many women. Medications been used in the past but is not on label approved and has basically fallen out of favor.
The predominant mechanism of treatment for women who desire intervention for stress urinary incontinence involves surgical approaches. There are variety of increasingly invasive ways that surgery can be undertaken. Transurethral bulking agents are relatively minimally invasive but offer less durable outcomes. urethropexy and abdominal/vaginal slings are also well accepted treatments.
However, transvaginal sling has become the go to treatment option in North America and certainly within Canada. This was developed in 1995 and first clinically used in Canada in 1999. A variety of approaches whether passing the tape in the traditional suprapubic way or through the obturator foramen.
This approach has become the standard of care in Canada and in part due to the ease of surgical insertion, lower cost, shorter procedures requiring only day surgery rather than hospitalization, as well as the ability to perform these with local anesthetics or with simple sedation as opposed to general anesthesia. Additionally, the outcomes of such approaches are proven to be very good with very durable and long term responses. As a result, this has become the gold standard for surgical management in female stress urinary incontinence and certainly in Canada.
However, the concerns have been raised and this occurred nearly a decade after the first introduction of these devices in Canada. These related to the use of pelvic mesh. Both in the United States within the Federal Drug Administration and in Canada from Health Canada, warnings came out regarding the use of pelvic mesh, although these do not specifically apply to transvaginal tapes for stress incontinence. In general, the effects are felt because firstly, complications related to these procedures were seen and as I alluded to before, stress incontinence procedures were grouped with pelvic organ prolapse, which is where a higher proportion of complications were identified. This was compounded by some relatively sensationalized reporting in the media. Finally, by increase in litigation and class action suits regarding mesh use.
As a result, we undertook the present study in order to characterize trends in the surgical management of female stress urinary incontinence in Canada. The advantage of studying this is Canada is that there's a single payer healthcare system, so we're truly able to comprehensively capture all patients who are undergoing surgery for stress incontinence over a greater than two-decade period. Then in concert with this approach, we wanted to assess whether regulatory healthcare warnings affected the utilization of transvaginal mesh procedures.
In order to do this, we undertook a retrospective cohort study of all women in Ontario undergoing surgical management of stress incontinence between 1994 and 2016. We used commonly applied procedural codes both at the patient level, at the physician level, and at the hospital level in order to make sure that we were able to identify both inpatient and outpatient procedures that were performed.
Using these fee codes, we were able to categorize the type of treatment that patients received, and we grouped these in four categories. First being urethropexy, second, transurethral bulking agents, third, abdominal/vaginal slings, and finally, transvaginal slings.
We performed an interrupted time-series analysis in order to characterize the trends in the utilization of these procedures over time. As a result, the passage of time was actually our primary exposure. The outcome that we considered was population-adjusted rates of these procedures. We corrected these rates to account for changing age of the population as well as overall population growth. So, this is expressed per 100,000 patient years.
In general, we can see that we identified just over 120,000 women with a mean age of around 52 who underwent these procedures. About a third received urodynamic assessment in the year prior to their surgery and about a third as well also had some form of pelvic organ prolapse surgery within the two years prior.
This is the meat and potatoes of the analysis. We'll break it through step by step, but the key is at the top line, the dark blue, is all procedures. So, what we see is relative stability through the 1990s with about 100 procedures per 100,000 women being performed. As soon as urethral slings or transvaginal slings were introduced, the overall rate of procedures rose. So that is more women in the population were undergoing surgery for stress urinary incontinence and prior to the introduction of the slings. This peaked around 2009 and then there's been a relatively precipitous decline in overall stress incontinence procedures that nears the individual procedures. We'll step through those as well.
Again, we see here in the 1990s, relative stability. Then with an inflection point when (Tension-free vaginal tape) TVT introduced in 1999, we see an increase in overall procedures as mentioned, but this is driven predominantly by increases in TVT. In 2,000, there was approximately 19 TVTs per 100,000 women and it rose to nearly 130 TVTs per 100,000 women at its peak. Then we see our warnings, the first one in 2008 from the FDA and then in 2010 from Health Canada. Then we see a precipitous decline. Here we see TVTs falling from 130 down to 60 per 100,000 women. The overall rate of any stress incontinence surgery fell from over 140 down to 64 in the last year of study. We see that while things like urethropexy and even abdominal/vaginal slings were not uncommon in the 1990s, these procedures declined significantly in the early 2000s such that they're nearly never performed in Ontario in the last five years. This has important implications as trainees are no longer exposed to these and so trainees who have undergone residency in the 2000s really are only familiar with TVT as the surgical approach stress urinary incontinence.
A few conclusions and then extrapolation here. First, rates of stress urinary incontinence increased from 1999 to 2009. This is driven by the introduction of transvaginal tape procedures. Second, the number of stress urinary incontinence procedures overall, as well as transvaginal tape procedures, significantly decreased after 2009, and continues to trend down. This timing does appear to be driven by the regulatory health warnings from both the FDA and from Health Canada.
Overall, we would interpret these data to show that regulatory health warnings had a significant effect on how patients and surgeons approach the treatment of stress urinary incontinence. As overall rates of surgery for stress urinary incontinence are well below historical rates prior to the introduction of TVT, that is now approximately 65 procedures per 100,000 women as opposed to nearly 100 in the 1990s, suggested there maybe a group of women in the community who are living with untreated stress urinary incontinence due to either their fears, their physician's fears, or overall cultural beliefs regarding the safety of mesh and this has discouraged treatment of any form for stress urinary incontinence.
Just to recap the data once more, we see the precipitous fall in overall stress incontinence procedures without concomitant rise in alternatives to TVT with the fears regarding TVT. This has important implications for the number of women who are living with untreated stress incontinence.
That concludes this talk. I hope you found it interesting. Certainly, there are other data from other jurisdictions that mirror these and so I think we need to rethink how we approach treating these women.