The evolution of incontinence into resolved, refractory and de-novo urgency urinary incontinence following sling placement at time of pelvic organ prolapse repair in a large urodynamic cohort (n=139)

Zhang X1, Shaffer R2, Dobberfuhl A1

Research Type


Abstract Category

Female Stress Urinary Incontinence (SUI)

Abstract 12
Stress Urinary Incontinence
Scientific Podium Short Oral Session 2
Urgency Urinary Incontinence Overactive Bladder Female Surgery
1. Stanford University, Dept. of Urology, 2. University of Colorado, Dept. of Obstetrics and Gynecology

Xinyuan Zhang



Hypothesis / aims of study
To improve counseling in women at risk of refractory and/or de-novo urgency urinary incontinence (UUI) following sling placement at time of prolapse repair, we created a UUI outcome model to characterize changes in storage dysfunction following surgery.
Study design, materials and methods
We identified 139 women who underwent urodynamics followed by prolapse repair with or without sling placement at our institution from 2009 to 2015 using Current Procedural Terminology (CPT) codes. Inclusion criteria included the presence of a Pelvic Organ Prolapse Quantification System (POP-Q) stage 2 or greater cystocele and at least 7 days of follow-up. Our primary outcome was the presence of UUI following sling placement at the time of prolapse repair. Patients were classified into either no, de-novo, resolved or refractory urgency urinary incontinence after prolapse surgery, when compared to their preoperative state prior to surgery. Data were analyzed in Statistical Analysis System software (SAS, Cary, NC) using chi-square and Fisher’s exact tests (categorical variables), Student t-test (continuous variables), and Kaplan-Meier methods. Tabulated data are presented as mean +/- standard deviation (SD). A p-value less than 0.05 was defined as significant. Kaplan‐Meier analysis with the Cox proportional hazard was performed to look at the association between time and the proportion of women free of UUI and stress incontinence at longest follow up after surgery, stratified by sling placement.
139 women (mean age, 62.6 +/- 11.4 years) met inclusion criteria, underwent urodynamics and were included for analysis. Baseline characteristics for sling and no sling group included age (years, 60.4 +/-11.9 vs. 65.6 +/- 10.1, p=0.006), and BMI (27.2 +/- 5.5 vs. 26.8 +/- 5.2, p=0.786). The most common POP-Q prolapse stage was stage 3 (77/139, 55.4%). Baseline POP-Q stage was well matched between the two groups (stage 2, p=0.989; stage 3, p=0.794; stage 4, p=0.408). Preoperative incontinence included (i) subjective, objective and occult stress urinary incontinence (SUI), and (ii) subjective and objective UUI. Subjective SUI was defined as patient report of symptoms such as leaking when coughing or lifting heavy objects. Objective SUI was defined as leakage of urine with valsalva observed during pelvic exam. Occult SUI was defined as absence of subjective incontinence but presence of urine leakage with prolapse reduced on pelvic exam. Subjective UUI was defined as patient report of symptoms such as urinary frequency as a result of strong urge to void or inability to hold before reaching the restroom. Objective UUI was defined as the presence of detrusor overactivity on urodynamics. Subcategories of SUI or UUI were not mutually exclusive. The sling group had a significantly higher subjective SUI [62/81 (76.5%) vs 18/58 (31.0%), p<0.001], objective SUI [62/81 (76.5%) vs. 6/58 (10.3%), p<0.001], and occult SUI [41/81 (56.8%) vs. 29/58 (50.0%), p<0.001) compared to the no sling group. There was no significant different in rates of baseline subjective UUI [46/81 (56.8%) vs. 29/58 (50.0%), p=0.428] and objective UUI [15/81 (18.5%) vs. 9/58 (15.5%), p=0.644]. Preoperative urodynamics (sling vs. no sling) demonstrated statistically significant differences in Pdet@Qmax (cmH2O, 17.6 vs. 24.6, p=0.005), Qmax (mL/s, 19.4 vs. 15.3, p=0.014), PVR (mL, 86.8 vs. 159.4, p=0.025), and bladder outlet obstruction index (BOOI=Pdet@Qmax-2*Qmax, 2.1 vs. 7.9, p=0.002). Otherwise, urodynamic capacity and BCI were similar between sling groups.

Following surgery women were followed for a mean follow-up of 859 days. Post-operatively, rates of subjective SUI, objective SUI, and further surgical treatments for SUI (bulking agent, repeat sling) were not statistically different between the sling groups. In the sling group following surgery, a significantly greater proportion of women had subjective UUI compared to the no sling group [44/81 (54.3%) vs. 19/58 (32.8%), p≤0.001]. Subsequently a highly proportion of women underwent further pharmacologic UUI treatments in the sling group (anticholinergics, beta-3 agonist), although not statistically significant. Additional treatments required for post-operative incomplete bladder emptying were characterized (alpha blocker, any requirement for intermittent catheterization, any requirement for indwelling catheterization, sling incision, and sling excision). There was a similar proportion of these treatments utilized after surgery, with the exception of greater requirement for indwelling catheterization following surgery in the sling group [13/81 (15.0%) vs. 3/58 (5.2%), p=0.048]. 

Women were stratified by type of UUI after surgery (never UUI, de-novo UUI, resolved UUI, and refractory UUI) with respect to the presence of UUI prior to surgery (Table 1). There was a similar proportion of women who never experienced UUI before or after surgery who underwent sling placement (20/81, 24.7%) when compared to those who did not undergo sling placement (19/58, 33.8%, p=0.341). In those women who underwent sling placement, following surgery they demonstrated de-novo (13/81, 16.0%) and resolved (17/81, 21.0%) UUI at a similar rate compared to those women who did not undergo sling placement [de-novo (6/58, 10.3%, p=0.454), and resolved (19/58, 32.8%, p=0.169) UUI]. Refractory UUI was demonstrated in a higher proportion of women following sling placement (31/81, 38.3%) compared to those who did not undergo sling placement (14/58, 24.1%, p=0.048).

On Kaplan-Meier analysis, there was no difference in the proportion of women not reporting SUI at the time of longest follow between the sling and no sling groups [HR 0.98 (95% CI 0.43-2.23), p=0.969]. For UUI, there was a trend towards a greater proportion of women not reporting UUI in the no sling group (Figure 1) compared to the sling group however this difference did not achieve statistical significance [HR 0.63 (95% CI 0.37-1.06), p=0.081].
Interpretation of results
Rates of de-novo and resolved UUI following prolapse repair did not differ regardless of concurrent sling placement at time of prolapse surgery. Refractory UUI was demonstrated in a higher proportion of women following sling placement compared to those who did not undergo sling placement.
Concluding message
Patients should be counseled on the risk of refractory UUI following sling placement.
Figure 1 Table 1. UUI classification following pelvic organ prolapse surgery
Figure 2 Figure 1. Kaplan-Meier curve for sling (dotted line) versus no sling (solid line) groups showing the proportion of women not reporting UUI at longest follow up
Funding NIH 1L30DK115056-01 Clinical Trial No Subjects Human Ethics Committee Institutional IRB Protocol # 35034 Helsinki Yes Informed Consent No
12/04/2024 13:15:36