Hypothesis / aims of study
Stress urinary incontinence (SUI) is a prevalent symptom in women. The most frequently used surgical therapy is insertion of a retropubic of transobturator midurethral sling (MUS). Complication rates are approximately 8% (1). A recent study showed that at 9-year follow-up 3.3% of women underwent sling removal (2). Vaginal and groin pain account for approximately 7% of these removals with or without other concomitant complications besides pain. Management of pain in patients after MUS can be challenging. In case conservative treatment fails, removal of MUS is generally considered the next step. Literature regarding MUS removal for pain as a single complication is scarce.
This study aims to evaluate the results of MUS removal in women who have pain as single complication. Primary outcome is the pain response. Secondary outcomes are the rate of recurrence of incontinence and possible predictors for a poor outcome of MUS removal.
Study design, materials and methods
After receiving institutional review board approval we identified all women who underwent partial or complete MUS removals for pain as the single reason for removal at our tertiary clinic between November 2004 and June 2018. We performed a retrospective chart study and supplemented this with a cross sectional patient responded questionnaire. The questionnaire is sent by mail. We collected demographics and pre and postoperative data from the patients electronic patient files. The primary outcome is pain levels measured using a visual analogue scale (VAS 0-10) from the questionnaires; their current VAS-score and retrospectively pre-operatively. Secondary outcomes are the recurrence or increase in SUI and to determine possible predictive factors for pain reduction (χ2 and Fisher exact) after MUS removal. Data for secondary outcomes was derived from both questionnaires and patient files.
We included 31 patients of which 26 filled out and returned the questionnaire. Mean age at time of MUS placement was 48 years (range 28-65). Median time interval between placement and removal of the MUS was 15 months (range 1-141). This interval dropped from a median of 64 months (range 1-141) before 2011, to a median of 12 months (range 1-54) after 2011 (p=.001). Pain is mentioned at multiple sites in 61%: in vagina, groin or abdomen in respectively 77%, 55% and 36%. Patients reported pain at one side, both sides or in the midline in 77%, 13% and 10% respectively. The amount of resected sling differed per patient after a median number of 1.0 surgeries per patient for MUS removal (range 1-4): one (3%) patient had a midline trans section, 10 (32%) had a partial one sided vaginal removal, 18 (58%) had a complete vaginal removal, one (3%) had an one sided groin removal and one (3%) had a complete groin and vaginal removal.
Questionnaire (n=26): Median follow-up was 25 months (5-104). Mean VAS-score dropped from a mean of 7.8 (SD 1.9) before removal to 4.5 (SD 3.2) at follow up (p<.000). 25% of patients were pain free (VAS=0) at follow-up. Patients who underwent partial vaginal resection with available VAS-score (n=6) had a VAS-score decrease of 4.7 (p=.021) compared to a decrease of 2.7 (p=.017) in patients who underwent a complete vaginal removal (n=14). The VAS in partial versus complete vaginal removal does not differ statistically (p=.378). Nineteen patients (79%) indicated a daily number of incontinence pads. Patients who experienced no or minimal bother from SUI (n=9) used median 2 pads a day (range 0-5). Women who are bothered by their SUI (n=10) used 3 pads a day (range 2-6) (p=.035). We could not identify predictive factors (menopause status, prior hysterectomy, tobacco use, fibromyalgia, diabetes, dystrophy, chronic abdominal pain, bladder pain syndrome and chronic pain) for pain reduction in this small cohort.
Electronic patient files (n=31): Median follow-up after MUS removal was 12 months (range 2-66). Postoperatively, 19 (61%) of all patients reported an increase of SUI. In those patients that underwent partial vaginal removal 50% reported an increase of SUI compared to 61% in patients that underwent complete vaginal removal (p=.967). Six (21%) of all patients with persistent SUI rejected any further SUI treatment, most often due to fear for recurrence of pain after renewed treatment. Of these 6 patients that rejected treatment 4 (67%) filled out the questionnaire with a median follow up of 38 months (range 19-57). None of these patients had any SUI treatment.
Interpretation of results
Pain after MUS is an invalidating complication with high VAS scores. Partial or complete removal of the MUS significantly alleviates pain and even resolves pain completely in 25% of patients. Incontinence increases in the majority due to resection of MUS.