Assessment and management of patients with chronic lower urinary tract symptoms following remote urethral sling surgery is not well defined. It is hypothesized that a significant portion of these patients may have a component of bladder outlet obstruction. The objectives of this study are to review patients with chronic urinary symptoms post-urethral sling surgery and to determine the incidence and clinical predictors of obstruction.

A single-center retrospective review was performed on all patients with a history of urethral sling surgery and >6 months of urinary symptoms between January 1st, 2014 and June 30th, 2021. Patients were excluded if they had met any of the following: 1) <18 years old, 2) Male, 3)  <6 months since sling surgery, 4) Baseline neurogenic voiding dysfunction, 5) incomplete records, 6) urinary symptoms preceding urethral sling placement, or 7) underwent other incontinence procedure (i.e. retropubic urethropexy/colpopexy, urethral bulking). All patients underwent history, physical exam, cystoscopy, and urodynamic testing (+/- fluoroscopy). Obstruction was identified by urodynamics using the Blaivas criteria or fluoroscopy (sustained PDet>20cmH2O with Qmax<12mL/s or if there was fluoroscopic evidence of obstructing sling - proximal urethral dilation with narrowing at area of sling). Clinical findings for patients with and without obstruction were compared. Patients undergoing sling lysis were assessed and post-operative outcomes were evaluated.

In total 106 patients were included, median age 61 years (IQR 19), median time since sling surgery 5 years (IQR 8). Fifty-nine percent (63/106) met the definition for bladder outlet obstruction. Patients with obstruction had significantly higher mean PDet@Qmax (35 vs 19 cmH2O), lower Q max (6 vs 14mL/s), and higher PVR (217 vs 72 mL) (p<0.05). A tight sub urethral band was the only clinical finding significantly associated with obstruction (p = 0.003). Time since sling surgery and type of urinary symptoms were not associated with obstruction. Fifty-one (80%) obstructed patients underwent sling lysis after which 90% reported improvement in voiding symptoms, 41% reported improvement in storage symptoms, and 43% reported recurrent incontinence (median follow-up 18 months – IQR 20.5).  Five patients (5/51 – 10%) underwent redo sling procedure.

The results of this study demonstrate that patients with urinary symptoms and remote urethral sling surgery (median time since sling surgery 5 years) have a high prevalence of bladder outlet obstruction on urodynamics. Only a tight palpable sub-urethral band was found to be associated with obstruction on logistic regression.  Other clinical findings, including type of urinary symptoms (i.e. storage vs voiding) did not correlate with obstruction on urodynamics. For patients undergoing sling lysis, most (89.7%) had improvement in voiding symptoms, however, over half had persistent storage symptoms.

There is a high incidence of obstruction in patients with chronic urinary symptoms following sling surgery, however, few clinical predictors exist and urodynamics may be warranted. Patients undergoing sling lysis should be observed for persistent storage symptoms and recurrent incontinence.