IUGA Meeting 2023 - Ulf Ulmsten Lecture: Measuring Prolapse

In a scintillating talk on Measuring Pelvic Organ Prolapse (POP), Dr. Barber started out by sharing how his understanding of the measurement of prolapse has evolved over time. The introduction of POP-Q in 1996 was revolutionary. It incorporates a staging system, its least important and most problematic aspect. It is worth noting that the POP-Q system was developed at a time when there was scant knowledge regarding normal vaginal support and the natural history of prolapse. The original lead author of the POP-Q paper, Dr. Bump noted in a review 18 years later that the initial subcommittee consensus was that there should be no ordinal rating system. However, they soon recognized this impracticality, given the ingrained status of prolapse grading in the gynecological community! Similarly, the 2001 NIH workshop on standardization of prolapse outcomes arbitrarily defined optimal anatomic outcome as stage 0 and satisfactory anatomic outcome as stage 1. However, cumulative evidence has revealed that the natural history of prolapse is a relatively slow process. It is dynamic, and though it tends towards progression, regression often occurs and is influenced by parity, genital hiatus, and weight.

At around the time of the creation of POP-Q, patient-reported outcome measures became equally important. “Seeing or feeling a vaginal bulge" is the most reliable and specific symptom of prolapse beyond the hymen. Bulge symptoms are dynamic and vary by the time of day and day to day. Also, bowel and bladder symptoms have a weak to moderate correlation with anatomic severity. There is a third dimension apart from anatomy and severity: bother. Anatomic and symptom severity correlate poorly with bother and care seeking and are influenced by body image, lifestyle, activity level, sense of well-being, age, race/ethnicity, health literacy, and economic status. Very importantly, we have also learned that prolapse is a multidimensional phenomenon as it also impacts the quality of life, function, body image, sexual function, and emotional health.

Considering the multidimensional nature of prolapse, the definition of prolapse has been revised based on an international consensus by the IUC (International Urogynecology Consultation on Prolapse) in 2021: prolapse is anatomic descent of the vaginal wall to or beyond the hymen and either: 1) bothersome characteristic symptoms (e.g., vaginal bulge) or medical or functional compromise (e.g., urinary retention, renal failure, severe vaginal erosions). 

Next, we have also learned that success rates are highly variable depending upon the criteria selected to define success. Definitions of anatomic success commonly used are too strict and often not clinically relevant; symptomatic cure, particularly the absence of vaginal bulge symptoms, is more clinically relevant than anatomic cure. There is a discordance between symptoms and anatomy when using a composite outcome of success. Also, POP failure states are dynamic over time. Traditional time-to-first event analysis methods overestimate POP failure rates. Therefore, evaluating POP outcomes independently rather than as a composite outcome may be more valuable. POP success and failure states are dynamic over time. We need to explore alternative analytic techniques that account for different outcome states in a single individual over time.

We now know that anatomic defects, symptoms, and quality of life and function have a variable impact on patient experience. Therefore, patient-reported outcome measures are the most valid and robust way to measure the presence, severity, and/or impact of pelvic floor symptoms on a patient’s activities and well-being.

Realizing this, IUC opined that surgical success should be primarily defined by the absence of bothersome patient bulge symptoms or retreatment for POP (surgery, pessary, or physical therapy). While anatomic outcomes should always be reported, success should not be defined solely by anatomic outcomes since they do not correlate well with patient perception of success or satisfaction.

Finally, Dr. Barber summarized all the areas in which he has personally evolved over time: patient-reported outcome measures (PROMs) need to be the primary outcome. Anatomy/POPQ should be a secondary outcome. No time for the first event analysis should be done. No composite outcomes should be used, and assessment should be done in multiple dimensions and use continuous data vs. arbitrary simplistic dichotomy into success and failure buckets. Fortunately, there are robust methods of interpreting PROMS, including minimal clinically important difference (MCID), substantial clinical benefit (SBC), and patient acceptable symptom state (PASS).

In the future, we need to develop PROMs for pelvic floor disorders with more significant patient input and use more contemporary approaches (e.g. IRT, PROMIS). There should be a standard set of outcome measures for RCTs and registries. Analytic approaches that account for dynamic changes and multiple dimensions should be used. Lastly, we need to better understand symptomatic patients with normal(ish) anatomy.