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].