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Assessment of voiding after sling: a randomized trial of 2 methods of postoperative catheter management after midurethral sling surgery for stress urinary incontinence in women

Published:November 27, 2014DOI:https://doi.org/10.1016/j.ajog.2014.11.033

      Objective

      The objective of this study was to compare the backfill standard voiding trial (SVT) that relies on the assessment of voided volume to subjective patients’ evaluation of their voiding based on the assessment of the force of stream (FOS) after an outpatient midurethral sling surgery.

      Study Design

      This double-blinded randomized trial included patients undergoing an outpatient midurethral sling surgery without any other concomitant surgery. Participants were randomized to either the SVT group or to the FOS group. The primary outcome was the rate of catheterization any time up to 6 weeks after surgery. Both groups underwent the same backfill voiding trial protocol postoperatively. Measurements of the voided amount, postvoid residual, and the response to the FOS visual analog scale were collected. The criteria for passing the voiding trial in the SVT group was voiding at least two-thirds of the instilled amount; while the criteria for passing the trial in the FOS group was assessment of FOS at least 50% of the baseline, regardless of the voided volume. Participants were interviewed preoperatively and 2-4 days, 7-9 days, and 6 weeks postoperatively. All postoperative interviews included assessments of pain, tolerance of physical activity, urinary FOS, as well as satisfaction with the surgery. Validated questionnaires (Incontinence Severity Index and Urinary Distress Inventory, short form) before the surgery and 6 weeks after were used to evaluate urinary symptoms.

      Results

      A total of 108 patients were enrolled and randomized, and 6-week follow-up data were available for 102 participants (FOS 50, SVT 52). The 2 groups were similar with respect to demographic characteristics and urinary symptoms. The incidence of catheterization was also similar between the groups (FOS 13 [26%], SVT 13 [25.5%]; P = .95). Amount voided had a moderate correlation with FOS assessment (Spearman rho 0.5; P < .001). There was no significant difference in mean catheter days, pain scores, Incontinence Severity Index, and Urinary Distress Inventory, short form scores between the 2 groups. Of the patients who were discharged home without a catheter in either group none required catheter reinsertion within 6 weeks after the surgery.

      Conclusion

      Patient’s subjective assessment of the urinary FOS correlated well with the measured voided amount and no difference in catheterization days was noted between the subjective and objective assessment of voiding. Thus subjective evaluation of the FOS is a reliable and safe method to use after outpatient midurethral surgery.

      Key words

      Midurethral sling (MUS) surgeries are among the most common procedures performed in the United States.
      • Oliphant S.S.
      • Wang L.
      • Bunker C.H.
      • Lowder J.L.
      Trends in stress urinary incontinence inpatient procedures in the United States, 1979-2004.
      MUS are less invasive than the Burch colposuspension and the autologous rectus fascia sling procedures and as such are associated with less blood loss and shorter recovery time without compromising the efficacy of treatment.
      • Meschia M.
      • Pifarotti P.
      • Bernasconi F.
      • et al.
      Tension-free vaginal tape: analysis of outcomes and complications in 404 stress incontinent women.
      • Paraiso M.F.
      • Walters M.D.
      • Karram M.M.
      • Barber M.D.
      Laparoscopic Burch colposuspension versus tension-free vaginal tape: a randomized trial.
      • Ward K.L.
      • Hilton P.
      UK and Ireland TVT Trial Group
      Tension-free vaginal tape versus colposuspension for primary urodynamic stress incontinence: 5-year follow up.
      Despite numerous advantages of these surgeries, 25-35% of patients are discharged home with indwelling catheters.
      • Barber M.D.
      • Kleeman S.
      • Karram M.M.
      • et al.
      Transobturator tape compared with tension-free vaginal tape for the treatment of stress urinary incontinence: a randomized controlled trial.
      • Dieter A.A.
      • Amundsen C.L.
      • Visco A.G.
      • Siddiqui N.Y.
      Treatment for urinary tract infection after midurethral sling: a retrospective study comparing patients who receive short-term postoperative catheterization and patients who pass a void trial on the day of surgery.
      The challenge for surgeons performing antiincontinence procedures is to avoid postoperative urinary retention and minimize the need for postoperative catheterization and its associated risks. In addition to being the leading cause of hospital-acquired urinary tract infections (UTIs),
      • Trautner B.W.
      • Darouiche R.O.
      Catheter-associated infections: pathogenesis affects prevention.
      indwelling catheters are also a source of discomfort, embarrassment, and inconvenience, particularly if patients desire to return to work or daily activities immediately. Additionally, many women are distressed by the idea of going home with a catheter. Elkadry et al
      • Elkadry E.A.
      • Kenton K.S.
      • FitzGerald M.P.
      • Shott S.
      • Brubaker L.
      Patient-selected goals: a new perspective on surgical outcome.
      evaluated how patients perceive surgical outcomes and found that 9% of women believed that being discharged with a catheter was a surgical complication and 15% named “catheter” as the worst aspect of their surgery.
      After antiincontinence surgery, an assessment of voiding function (voiding trial) is often performed to determine who can be safely discharged without a catheter. A commonly described voiding trial technique is the backfill-assisted voiding trial, which involves filling the bladder with 300 mL of sterile fluid via the catheter while in the recovery room, removing the catheter, and allowing the patient to void. The patient is discharged with an indwelling catheter if the voided amount is less than two-thirds the infused volume.
      • Foster Sr., R.T.
      • Borawski K.M.
      • South M.M.
      • Weidner A.C.
      • Webster G.D.
      • Amundsen C.L.
      A randomized, controlled trial evaluating 2 techniques of postoperative bladder testing after transvaginal surgery.
      When utilizing this protocol, approximately 35% of patients require catheterization after a sling.
      • Barber M.D.
      • Kleeman S.
      • Karram M.M.
      • et al.
      Transobturator tape compared with tension-free vaginal tape for the treatment of stress urinary incontinence: a randomized controlled trial.
      This backfill-assisted voiding trial technique has been shown to be more efficient than the alternative of simply removing the catheter, waiting for a patient to void after parenteral or oral hydration, and then measuring a postvoid residual (PVR).
      • Foster Sr., R.T.
      • Borawski K.M.
      • South M.M.
      • Weidner A.C.
      • Webster G.D.
      • Amundsen C.L.
      A randomized, controlled trial evaluating 2 techniques of postoperative bladder testing after transvaginal surgery.
      Despite being widely used in multiple randomized trials,
      • Foster Sr., R.T.
      • Borawski K.M.
      • South M.M.
      • Weidner A.C.
      • Webster G.D.
      • Amundsen C.L.
      A randomized, controlled trial evaluating 2 techniques of postoperative bladder testing after transvaginal surgery.
      • Dieter A.A.
      • Amundsen C.L.
      • Edenfield A.L.
      • et al.
      Oral antibiotics to prevent postoperative urinary tract infection: randomized controlled trial.
      the precise requirements for volume voided or PVR volumes have not been critically evaluated, particularly for outpatient minimally invasive sling surgeries.
      An alternative method of voiding evaluation, which utilizes a visual analog scale (VAS) ascertaining the urinary force of stream (FOS) after surgery relative to the force prior to surgery has been reported.
      • Ingber M.S.
      • Vasavada S.P.
      • Moore C.K.
      • Rackley R.R.
      • Firoozi F.
      • Goldman H.B.
      Force of stream after sling therapy: safety and efficacy of rapid discharge care pathway based on subjective patient report.
      This method specifies the criteria for discharge without a catheter as a subjective report by the patient of her FOS that is >50% of her baseline FOS using a VAS (Figure 1). In this study, 94.6% of patients were discharged home without a catheter and with no incidence of acute voiding dysfunction necessitating recatheterization. While subjective patient evaluation of voiding appears to be safe, it is not known how patient’s subjective perception of voiding correlates with the measured voided volume or the PVR volume. The objective of this study was to compare the backfill standard voiding trial (SVT) to the FOS voiding trial in a double-blind randomized controlled trial and to determine if subjective patient evaluation is a safe method to determine the need for indwelling catheterization after an outpatient sling surgery. Our hypothesis was that the rate of catheterization would be significantly lower when using the FOS technique as compared to the backfill voiding trial.
      Figure thumbnail gr1
      Figure 1Force of stream visual analog scale
      100% = Urinary force of stream at baseline, presurgery; 50% = Cutoff for passing voiding trial, discharge home without catheter.
      Tunitsky-Bitton. Assessment of voiding after sling: a randomized trial. Am J Obstet Gynecol 2015.

      Materials and Methods

      In this double-blinded randomized trial, patients undergoing an outpatient MUS surgery for female stress urinary incontinence were eligible for participation. Participants were excluded if the surgery involved any concomitant urinary tract or pelvic reconstructive procedure or if the procedure, in itself, necessitated postoperative catheterization, as in the event of a cystotomy. Participants with a history of neurologic conditions affecting the urinary tract system, pelvic organ prolapse beyond the hymen during straining (any compartment), or previous antiincontinence procedure were also excluded. Eligible patients were recruited preoperatively and all participants signed an institutional review board–approved research informed consent form. All participants received a single prophylactic dose of intravenous antibiotics at the time of the procedure. All participants underwent the same standardized postoperative protocol in the recovery room that included backfilling the bladder with 300 mL of normal saline solution through the transurethral catheter, removing the catheter, and allowing the participant to void within 30 minutes. PVR was measured using bedside ultrasound. All participants were asked to assess their voiding using FOS VAS, by comparing the postoperative FOS with the preoperative FOS on a scale of 0-120%, given that preoperative FOS is 100% (Figure 1).
      • Ingber M.S.
      • Vasavada S.P.
      • Moore C.K.
      • Rackley R.R.
      • Firoozi F.
      • Goldman H.B.
      Force of stream after sling therapy: safety and efficacy of rapid discharge care pathway based on subjective patient report.
      Participants were randomly assigned using a 1:1 allocation ratio to 2 different criteria for catheter management. Participants randomized into the SVT group were discharged with a catheter if the voided amount was <200 mL and the PVR was greater than one third of the total amount. The participants in the FOS group were discharged with the catheter if they reported the FOS to be <50% of their baseline FOS, regardless of the voided amount and the PVR (Figure 2).
      Figure thumbnail gr2
      Figure 2Study protocol
      FOS, force of stream voiding trial; SVT, standard voiding trial.
      a Midurethral slings include transobturator slings and retropubic slings; b FOS measured using visual analog scale; c Postvoid residual (PVR) measured by bladder ultrasound. PVR is assessed in both groups, but used only in SVT group.
      Tunitsky-Bitton. Assessment of voiding after sling: a randomized trial. Am J Obstet Gynecol 2015.
      Treatment allocation was made by a computer-generated random numbers table using randomly permuted blocks of varying sizes of 4, 6, and 8 known only to research nurses not involved in patient recruitment or data collection. Randomization was stratified by surgeon (8 surgeons). Group allocation was revealed after surgery in the recovery nursing unit by opening an opaque envelope with specific instructions regarding the postoperative voiding assessment. The patient as well as all study investigators, the surgeon, and the research coordinator remained masked to treatment assignment throughout the study and data analysis.
      The primary outcome of the study was the rate of catheterization within 6 weeks after the surgery. We hypothesized that the rate of catheterization within a 6-week period after surgery would be lower in the FOS group than in the SVT group. Secondary outcomes were the rate of UTI, efficacy of the procedure as measured by validated questionnaires, patient’s postoperative pain, and activity level as well as satisfaction with the surgery.
      Participants completed a series of questionnaires at 4 time points: preoperatively and 2-4 days, 7-9 days, and 6 weeks postoperatively. The questionnaires were administered in a telephone interview by a masked investigator or a research assistant. Preoperative and 6-week postoperative interviews included validated questionnaires that evaluate urinary incontinence (Incontinence Severity Index [ISI] and Urinary Distress Inventory, short form [UDI-6]).
      • Uebersax J.S.
      • Wyman J.F.
      • Shumaker S.A.
      • McClish D.K.
      • Fantl J.A.
      Short forms to assess life quality and symptom distress for urinary incontinence in women: the incontinence impact questionnaire and the urogenital distress inventory; continence program for women research group.
      • Sandvik H.
      • Hunskaar S.
      • Seim A.
      • Hermstad R.
      • Vanvik A.
      • Bratt H.
      Validation of a severity index in female urinary incontinence and its implementation in an epidemiological survey.
      The preoperative interview also included questions regarding patient’s expectations. The questionnaire asked that the patient rate how important it is to have “Good control of pain immediately after the surgery,” “Minimal pain within 1 week of the surgery,” “Going home without a bladder catheter,” and “Returning to my daily activities (other than work) within a few days of the surgery,” and “Returning to work within the time frame that is acceptable.” The responses were ranked as “Not important,” “slightly important,” “moderately important,” and “greatly important.” Data regarding medical comorbidities were collected from the medical record using the Charlson Comorbidity Index.
      • Charlson M.E.
      • Pompei P.
      • Ales K.L.
      • MacKenzie C.R.
      A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.
      All postoperative interviews included assessments of pain using a pain scale that addressed general pain and pain specifically generalized to the genital urinary area,
      • Price D.D.
      • McGrath P.A.
      • Rafii A.
      • Buckingham B.
      The validation of visual analogue scales as ratio scale measures for chronic and experimental pain.
      voiding (using FOS scale), and tolerance of physical activity.
      • McCarthy Jr., M.
      • Jonasson O.
      • Chang C.H.
      • et al.
      Assessment of patient functional status after surgery.
      Satisfaction with the surgery was assessed at the 3 postoperative interviews with the question: “How satisfied are you with the surgery?” Possible responses were: “very satisfied,” “somewhat satisfied,” “somewhat dissatisfied,” or “very dissatisfied.” Incidence of UTI was determined by reviewing the electronic medical record and by asking the subjects at the time of postoperative interview if they had called a physician or had been seen for any reason by a medical provider and the patient reported that she was seen and/or treated for a UTI. Presence of UTI was considered positive even if she was treated based on symptoms, in the absence of a positive culture. During each interview specific symptoms of voiding dysfunction and UTI were assessed, and if positive the subjects were prompted to contact their physician and the results were followed up by the research staff.
      A sample size of 51 participants per group provided 80% power to detect a 10% difference in the rate of catheterization between the 2 methods, provided that the incidence of catheterization rate is 35% based on the previous studies.
      • Barber M.D.
      • Kleeman S.
      • Karram M.M.
      • et al.
      Transobturator tape compared with tension-free vaginal tape for the treatment of stress urinary incontinence: a randomized controlled trial.
      Assuming a 5% loss to follow-up, the total sample size required was 108 (54 per group). All statistical analyses were performed using the intention-to-treat principal. Descriptive statistics were used to report the primary and secondary outcomes including the rates and 95% confidence intervals (CIs). Categorical variables were described with frequencies and percentages. The primary outcome (rate of postoperative catheterization) was determined using Pearson χ2 test, as were other categorical variables. Continuous variables were compared using Student t tests. Software (JMP, version 10; SAS Institute, Cary, NC) was used to conduct statistical analysis.

      Results

      This trial was approved by the Institutional Review Board (11-082) and registered on clinicaltrials.gov (NCT01343784). In all, 108 participants were recruited for this randomized trial (53 in SVT group and 55 in FOS). The data for the assessment in the recovery room were not recorded for 2 and 6 participants in SVT and FOS group, respectively. All data for 102 participants (50 in SVT group and 52 in FOS) were complete at the 6-week follow-up (Figure 3). Recruitment for this study occurred in multiple different locations in our health system across northeast Ohio. Due to limited study personnel, we relied on surgeons to identify patients who met study criteria and a study nurse contacted the patient to verify criteria and obtain consent. This did not allow us to obtain an accurate screening and exclusion denominator. Overall, the randomization was successful; with similar baseline participant characteristics in both groups (Table 1). The overall catheterization rate was not significantly different between the 2 voiding trial interventions (SVT 13 [26.0%], FOS 13 [25%], difference 1%; 95% CI, –15.6% to +17.7%; P = .95) (Table 2). Mean number of catheterization days was 3.4 (±2.1) for the FOS group, and 2.4 (±1.1) for the SVT group (P = .14); 2-4 days after surgery 5 (10.2%) participants in the FOS group and 6 (11.3%) in the SVT group had a catheter in place (Table 2). The mean voided volume, and PVR and FOS values were likewise not statistically different between the groups. Voided amount had a moderate correlation with FOS (Spearman rho 0.5; P < .001).
      Figure thumbnail gr3
      Figure 3Flow diagram of participant enrollment and follow-up
      Force of stream (FOS) voiding trial.
      MI, myocardial infarction; NNT, number needed to treat; SVT, standard voiding trial; TVT, tension-free vaginal tape.
      Tunitsky-Bitton. Assessment of voiding after sling: a randomized trial. Am J Obstet Gynecol 2015.
      Table 1Patient demographics and baseline characteristics
      Patient characteristics
      Continuous data presented as median (range), Student t test, and categorical data presented as number (%), Wilcoxon signed rank test
      FOS (n = 53)SVT (n = 55)P value
      Age, y55.44 (35.8–78.11)57.21 (35.0–76.07).97
      White race47 (92.2%)49 (96.1%).34
      Parity2 (0–7)2 (0–5).57
      BMI, kg/m228.9 (18.78–51.9)30.0 (18.8–47.36).95
      CCI
      Predicts 10-y mortality for patient who may have range of comorbid conditions, total of 22 conditions, score is age-adjusted and 10-y survival calculated.
      2 (0–7) 0.90 (0–0.98)0 (0–5) 0.90 (0.21–0.98).99 .58
      Urinary urgency symptoms preoperatively26 (52%)34 (64.2%).57
      Urinary frequency22 (44%)28 (53%).37
      Nocturia16 (32%)21(40%).42
      Anticholinergic medication use preoperatively5 (10%)2 (3.8%).21
      Retropubic/transobturator sling29/2430/25.15
      ISI score6 (0–12)6 (0–12).83
      UDI-6 score85.0 (33.3–100)83.3 (16.7–100).44
      BMI, body mass index; CCI, Charlson Comorbidity Index; FOS, force of stream; ISI, Incontinence Severity Index; SVT, standard voiding trial; UDI-6, Urinary Distress Inventory, short form (from Pelvic Floor Distress Inventory 20).
      Tunitsky-Bitton. Assessment of voiding after sling: a randomized trial. Am J Obstet Gynecol 2015.
      a Continuous data presented as median (range), Student t test, and categorical data presented as number (%), Wilcoxon signed rank test
      b Predicts 10-y mortality for patient who may have range of comorbid conditions, total of 22 conditions, score is age-adjusted and 10-y survival calculated.
      Table 2Perioperative and postoperative findings
      FindingFOS (n = 52)SVT (n = 50)P value
      Perioperative evaluation
      Continuous data presented as median (range), Student t test; and categorical data presented as number (%), Wilcoxon signed rank test
       Amount voided, mL200 (0–400)275 (0–500).16
       Postvoid residual, mL107.5 (0–544)66 (0–600).53
       FOS,
      Determined using visual analog scale where 100% corresponds to FOS at baseline, score ranges from 0% (unable to void) to 120% (20% better than at baseline).
      %
      70 (0–110)85 (0–120).40
       Discharged with catheter13 (26%)13 (25.5%).95
      Postoperative evaluation: day 2–4
      Continuous data presented as median (range), Student t test; and categorical data presented as number (%), Wilcoxon signed rank test
       General pain (0–10)2 (0–7)1 (0–9).65
       Urethral and vaginal pain (0–10)1.9 (0.28) 2 (0–7)2.2 (0.27) 2 (0–8).38
       Urinary urgency11 (22.5%)10 (19.2%).69
       Narcotic medication use24 (49.0%)18 (34.0%).12
       Nonnarcotic medication use25 (51.0%)27 (51.0%).99
       Presence of catheter5 (10.2%)6 (11.32%).86
       FOS, %100 (50–110)100 (20–120).85
       Very/somewhat satisfied with surgery32 (65%)/15 (31%)38 (72%)/13 (25%).78
      Postoperative evaluation: day 7–9
      Continuous data presented as median (range), Student t test; and categorical data presented as number (%), Wilcoxon signed rank test
       General pain (0–10)0 (0–5)0 (0–6).34
       Urethral and vaginal pain (0–10)1 (0–7)0 (0–9).62
       Urinary urgency13 (26%)10 (19.3%).41
       Urinary urgency13 (26%)10 (19.3%).41
       Narcotic medication use6 (11.8%)7 (13.5%).80
       Nonnarcotic medication use14 (27.5%)13 (24.1%).53
       Presence of catheter00
       FOS100 (50–120)100 (50–120).66
       Very/somewhat satisfied with surgery36 (72%)/13 (26%)42 (79%)/10 (19%)
      Postoperative evaluation: week 6
      Continuous data presented as median (range), Student t test; and categorical data presented as number (%), Wilcoxon signed rank test
       General pain (0–10)0 (0–5)0 (0–7).26
       Urethral and vaginal pain (0–10)0 (0–1)0 (0–4).13
       Urinary urgency23 (48.9%)15 (30.6%).07
       Narcotic medication use1 (2.1%)0 (0%).20
       Nonnarcotic medication use6 (12.8%)4 (8.2%).46
       Presence of catheter00
       FOS100 (40–120)100 (75–120).56
       Very/somewhat satisfied with surgery34 (72%)/10 (21%)38 (78%)/7 (14%).65
       ISI score0 (0–8)0 (0–8).08
       UDI-633.3 (0–100)19.4 (0–100).13
      FOS, force of stream; ISI, Incontinence Severity Index; SVT, standard voiding trial; UDI-6, Urinary Distress Inventory, short form (from Pelvic Floor Distress Inventory 20).
      Tunitsky-Bitton. Assessment of voiding after sling: a randomized trial. Am J Obstet Gynecol 2015.
      a Continuous data presented as median (range), Student t test; and categorical data presented as number (%), Wilcoxon signed rank test
      b Determined using visual analog scale where 100% corresponds to FOS at baseline, score ranges from 0% (unable to void) to 120% (20% better than at baseline).
      Baseline ISI and UDI-6 scores significantly improved after the surgery in both groups and did not differ between the groups (mean difference in the ISI score was –5.9 [±0.44], and the mean difference in the UDI score was –49.0 [±3.9]). Postoperative evaluation revealed no difference in general pain scores, or the pain scores in the genitourinary area at any time points (Table 2). The majority of the patients (93 [91%]) reported that they were “satisfied” or “very satisfied” with the surgery at the 6-week postoperative evaluation (Table 2). Table 3 summarizes postoperative recovery as ascertained by the questionnaire measuring difficulty with various daily activities. A majority of participants had no difficulty with any of the daily activities even in the early postoperative period and improvement was noted at 7-9 days and 6 weeks postoperatively. There was significant difference in the activity tolerance between the groups at 6 weeks; however this difference was driven by few patients in the SVT group reporting more difficulty. As the baseline activity level for these patients is not known, the clinical significance of this finding is uncertain and is unlikely attributable to the group assignment.
      Table 3Postoperative activity level assessment
      VariableFOS (n = 52)SVT (n = 50)P value
      How much difficulty are you experiencing when performing the following activities?
      Postoperative evaluation: day 2–4
       Sitting1: 56%1: 41.5%.43
      2: 30.1%2: 35.9%
      3: 11.9%3: 20.9%
      4: 2%4: 1.9%
       Getting in and out of bed1: 53.1%1: 31.5%.04
      2: 34.7%2: 33.3%
      3: 8.2%3: 22.2%
      4: 4.1%4: 13%
       Walking around inside1: 74%1: 68.5%.83
      2: 22%2: 22.2%
      3: 4%3:7.4%
      4:1.9%
       Walking around outside1: 78.2%1: 67.92%.55
      2: 14%2: 18.9%
      6: 7.8%3: 7.6%
      6: 5.7%
       Climbing stairs1: 64%1: 56.6%.07
      2: 30%2: 20.8%
      3: 4%3: 18.9%
      6: 2%6: 3.8%
       Performing light housework1: 76%1: 57.4%.02
      2: 18%2: 13%
      6: 3%3: 7.4%
      4: 1.9%
      5: 1.9%
      6: 11%
      Postoperative evaluation: day 7–9
       Sitting1: 70.6%1: 60.4%.46
      2: 21.6%2: 32.1%
      3: 7.8%3: 5.7%
      4: 1.9%
       Getting in and out of bed1: 76%1: 68.5%.38
      2: 18%2: 24.1%
      3: 6%3: 1.9%
      4: 3.7%
      5: 1.9%
       Walking around inside1: 92.2%1: 88.9%.86
      2: 5.9%2: 9.3%
      3: 2%3: 1.9%
       Walking around outside1: 88.2%1: 83.3%.78
      2: 9.8%2: 14.8%
      3: 2%3: 1.9%
       Climbing stairs1: 84%1: 73.6%.07
      2: 16%2: 18.9%
      3: 5.7%
      4: 1.9%
       Performing light housework1: 86.3%1: 81.5%1
      2: 9.8%2: 11.1%
      3: 2%3: 3.7%
      6: 2%6: 3.7%
      Postoperative evaluation: week 6
       Sitting1: 100%1: 96.15%.005
       Getting in and out of bed1: 97.9%1: 96.2%.04
      2: 2.1%2: 1.9%
      3: 1.9%
       Walking around inside1: 97.9%1: 94.2%.024
      2: 2.1%2: 1.9%
      3: 3.9%
       Walking around outside1: 97.9%1: 94.2%.02
      2: 2.1%2: 1.9%
      3: 3.9%
       Climbing stairs1: 95.8%1: 92.3%.059
      2: 2.1%2: 1.9%
      3: 2.1%3: 3.9%
      4: 1.9%
       Performing light housework1: 97.9%1: 94.1%.005
      3: 2.1%2: 5.9%
      Categorical data presented as number (%), Fisher exact test. 1 = No difficulty; 2 = Little difficulty; 3 = Some difficulty; 4 = A lot of difficulty; 5 = Cannot perform; 6 = Have not performed.
      FOS, force of stream; SVT, standard voiding trial.
      Tunitsky-Bitton. Assessment of voiding after sling: a randomized trial. Am J Obstet Gynecol 2015.
      Overall, the complication rate was low. One patient in SVT group underwent sling removal for groin pain after a retropubic sling. Another patient in the FOS group underwent a retropubic sling revision due to report of incomplete voiding and urinary urgency, however this occurred >6 weeks' postoperatively. None of the participants who were discharged without a catheter returned for voiding dysfunction necessitating catheter reinsertion during the 6-week postoperative period (0/76; 95% CI, 0–5.8%). However, 2 participants (1 in each group) who were discharged with an indwelling catheter and successfully passed a subsequent backfill voiding trial, returned to the office with report of incomplete emptying and had a catheter reinserted for an elevated PVR within 2 days after surgery. After an additional week (approximately 2 weeks since the surgery), both patients were able to have the catheter removed and had no further symptoms. There were 6 cases of UTI (6.6%), 3 patients in each group (P = 1). Two of the patients were discharged home with a catheter. Two patients were readmitted within 6 weeks of surgery: 1 patient (FOS) had a scheduled elective orthopedic surgery and the other patient (SVT) was readmitted with asthma exacerbation 2 weeks after the surgery. Two patients, 1 in each group, died during the study period. One patient had a sudden and unexplained death on postoperative day 4. The other patient was admitted to an outside hospital with chest pain and had a myocardial infarction 5 weeks postoperatively. Both cases were reviewed by the institutional review board and it was determined that the outcome was not related to the study protocol.
      The preoperative questionnaire regarding patients’ expectations of their postoperative recovery revealed that being discharged home without a catheter was greatly important to 72% of patients (FOS 77.3%, SVT 67.4%; P = .54). In all, 49.5% of participants reported that good pain control was greatly important immediately after the surgery (FOS 53.9%, SVT 45.5%; P = .42). In all, 59.3% of participants viewed good pain control within 1 week of the surgery as greatly important (FOS 62.3%, SVT 56.4%; P = .47). In all, 60.4% of participants stated that returning to their daily activities within a few days postoperatively was greatly important (FOS 67.3%, SVT 53.7%; P = .43); and to 43%, returning to work within anticipated time frame was greatly important (FOS 64.7%, SVT 64.9%, P = .69).
      Six weeks postoperatively, when asked “What was the worst part of your experience with the surgery?” 19 patients (76% of the 25 patients discharged with the catheter) replied “catheter.” In all, 22 (20%) reported that the recovery was worse than expected; 16 (14.8%) were not satisfied with the surgical outcome; 7 (6.5%) found postsurgical limitations to be the worst part of their experience. No significant difference was noted between the 2 study groups.

      Comment

      Our study demonstrated no difference in catheterization rate between the voiding trial that relies on volume criterion for discharge decision with or without a catheter and the trial that uses patient’s subjective evaluation of her voiding after an outpatient MUS procedure.
      The rate of catheterization in our study is lower than previously reported. In a randomized trial that compared retropubic vs transobturator MUS, the rate was 31% and 36%, respectively.
      • Barber M.D.
      • Kleeman S.
      • Karram M.M.
      • et al.
      Transobturator tape compared with tension-free vaginal tape for the treatment of stress urinary incontinence: a randomized controlled trial.
      In contrast to these studies, our study was focused on outpatient sling procedures only, excluding concomitant prolapse surgeries. Prolapse repair likely increases the need for catheterization due to the change in configuration of the bladder and vaginal tissue, increased edema, increased anesthesia time, and increased opioid use. The median number of days with the catheter was 2.5 days (range, 2–7), which is similar to other randomized trials.
      • Barber M.D.
      • Kleeman S.
      • Karram M.M.
      • et al.
      Transobturator tape compared with tension-free vaginal tape for the treatment of stress urinary incontinence: a randomized controlled trial.
      • Foster Sr., R.T.
      • Borawski K.M.
      • South M.M.
      • Weidner A.C.
      • Webster G.D.
      • Amundsen C.L.
      A randomized, controlled trial evaluating 2 techniques of postoperative bladder testing after transvaginal surgery.
      • Dieter A.A.
      • Amundsen C.L.
      • Edenfield A.L.
      • et al.
      Oral antibiotics to prevent postoperative urinary tract infection: randomized controlled trial.
      It appears to be safe to remove the catheter as soon as possible postoperatively, even after initial discharge with the catheter.
      Patients’ subjective perception of their voiding had a moderate correlation to voided volume and therefore can be safely used to assess for the need of indwelling catheter postoperatively in this setting. When utilizing the same FOS VAS in a prospective study, Ingber et al
      • Ingber M.S.
      • Vasavada S.P.
      • Moore C.K.
      • Rackley R.R.
      • Firoozi F.
      • Goldman H.B.
      Force of stream after sling therapy: safety and efficacy of rapid discharge care pathway based on subjective patient report.
      concluded that the method is safe as none of the patients required recatheterization despite PVR volumes of >150 mL (range, 152–427) in 14 (12%) patients who passed the protocol. The authors concluded that a voiding trial utilizing FOS scale is not only safe but allows for a more efficient discharge process, with a mean recovery room time of 130.6 min (±48.3).
      • Ingber M.S.
      • Vasavada S.P.
      • Moore C.K.
      • Rackley R.R.
      • Firoozi F.
      • Goldman H.B.
      Force of stream after sling therapy: safety and efficacy of rapid discharge care pathway based on subjective patient report.
      A subset of patients in the same study underwent filling the bladder with 200-300 mL of fluid immediately after cystoscopy and the catheter was not reinserted prior to leaving the operating room. To maintain masking in this study, the patients in both groups underwent backfill of the bladder as part of the voiding trial. Therefore, we cannot conclude that our findings can be extrapolated to recommend bladder filling in the operating room. In our study, no patient in either group discharged without a catheter required catheterization in the postoperative period. As such, it may be unnecessary to measure the PVR as part of the voiding trial and using the FOS method may expedite the postoperative recovery process and decrease the discomfort for the patient and burden on the nursing staff.
      The success rates of the MUS in our study were high as judged by the significant decrease in the UDI-6 and ISI scores and these results are consistent with what has been previously reported.
      • Barber M.D.
      • Kleeman S.
      • Karram M.M.
      • et al.
      Transobturator tape compared with tension-free vaginal tape for the treatment of stress urinary incontinence: a randomized controlled trial.
      • Richter H.E.
      • Albo M.E.
      • Zyczynski H.M.
      • et al.
      Retropubic versus transobturator midurethral slings for stress incontinence.
      The high satisfaction rate of 91% that we reported in our study also confirms the efficacy of this procedure at least in the short term. Our study provides additional data about patients’ expectations. Often the surgeons are focused on success of the surgery while the patients may be focused on other aspects of their experience with surgery. The vast majority of the patients in our study (64%) stated that not having a catheter at discharge is “greatly important” to them and 76% of patients discharged with a catheter named “catheter” as the worst part of their experience. Surgeons should be sensitive to the fact that catheterization is a source of anxiety for many patients and thus preoperative counseling is important when managing expectations regarding the possibility of needing an indwelling catheter postoperatively. The postoperative data regarding pain and tolerance of daily activities likewise provide important information that can be used in counseling of patients before a MUS. It confirms that MUS surgery is well tolerated, and has a short recovery period.
      Duration of catheterization leads to increased incidence in catheter-associated UTI, which is the leading nosocomial infection.
      • Trautner B.W.
      • Darouiche R.O.
      Catheter-associated infections: pathogenesis affects prevention.
      The rate of the UTI in our study was low at 6.6% and, interestingly, did not correlate with catheter use. The rate of UTI may be underestimated as not all patients were treated at our facility and may have been treated empirically by a primary care provider. However, as part of the postoperative questionnaire, we asked if the participants were evaluated for any reason since their surgery or if they had any symptoms suggestive of a UTI. Therefore, we believe that our estimate of the UTI incidence is accurate. Because this cohort included patients undergoing MUS exclusively it is possible that the rate of UTIs is lower than among patients who have concomitant prolapse repair. In a randomized control study assessing the need for antibiotic use in an attempt to prevent catheter-associated UTI, the rate of UTI was found to be 10-18%, and the authors did not find a difference between the UTI rate among patients with and without concomitant pelvic floor reconstructive surgery.
      • Dieter A.A.
      • Amundsen C.L.
      • Edenfield A.L.
      • et al.
      Oral antibiotics to prevent postoperative urinary tract infection: randomized controlled trial.
      Similarly, in the trial comparing retropubic slings with transobturator slings (The Trial of Mid-Urethral Slings) the rate of UTI was 15.4% in the retropubic sling group and 9.0% in the transobturator sling group.
      • Richter H.E.
      • Albo M.E.
      • Zyczynski H.M.
      • et al.
      Retropubic versus transobturator midurethral slings for stress incontinence.
      In a retrospective study that evaluated rate of UTI after outpatient MUS without administering preoperative antibiotics, Harmanli et al
      • Harmanli O.
      • Boyer R.L.
      • Metz S.
      • Tunitsky E.
      • Jones K.A.
      Double-blinded randomized trial of preoperative antibiotics in midurethral sling procedures and review of the literature.
      found that the rate of UTI was only 8%. When comparing these 2 studies, it does appear that concomitant pelvic surgery would increase the incidence of UTIs.
      Strengths of our study include the prospective randomized double-blind trial design, a clearly defined patient population undergoing outpatient MUS surgery without any concomitant procedures, and excellent follow-up data. The observed catheterization rate in our study was 25%, which is lower than the 35% rate used in our power calculation that was based on the previous studies.
      • Barber M.D.
      • Kleeman S.
      • Karram M.M.
      • et al.
      Transobturator tape compared with tension-free vaginal tape for the treatment of stress urinary incontinence: a randomized controlled trial.
      To maintain blinding, we had both groups undergo the same backfill protocol. Therefore these data may not be extrapolated to spontaneous fill or leaving the bladder full after cystoscopy and going to recovery room without a catheter. Likewise FOS voiding trial may not be applicable to prolapse reconstructive surgeries, as it was not the focus of this study. These limitations notwithstanding, we conclude that patient’s subjective assessment of FOS correlates well with the measured voided amount and thus is a reliable and safe method to use after outpatient midurethral surgery.

      Acknowledgment

      Geetha Krishnan, RN, contributed significantly as a research nurse in this study, by overseeing the adherence to the protocol, and contributing to the telephone interviews, data collection, and data entry.

      References

        • Oliphant S.S.
        • Wang L.
        • Bunker C.H.
        • Lowder J.L.
        Trends in stress urinary incontinence inpatient procedures in the United States, 1979-2004.
        Am J Obstet Gynecol. 2009; 200: 521.e1-521.e6
        • Meschia M.
        • Pifarotti P.
        • Bernasconi F.
        • et al.
        Tension-free vaginal tape: analysis of outcomes and complications in 404 stress incontinent women.
        Int Urogynecol J Pelvic Floor Dysfunct. 2001; 12: S24-S27
        • Paraiso M.F.
        • Walters M.D.
        • Karram M.M.
        • Barber M.D.
        Laparoscopic Burch colposuspension versus tension-free vaginal tape: a randomized trial.
        Obstet Gynecol. 2004; 104: 1249-1258
        • Ward K.L.
        • Hilton P.
        • UK and Ireland TVT Trial Group
        Tension-free vaginal tape versus colposuspension for primary urodynamic stress incontinence: 5-year follow up.
        BJOG. 2008; 115: 226-233
        • Barber M.D.
        • Kleeman S.
        • Karram M.M.
        • et al.
        Transobturator tape compared with tension-free vaginal tape for the treatment of stress urinary incontinence: a randomized controlled trial.
        Obstet Gynecol. 2008; 111: 611-621
        • Dieter A.A.
        • Amundsen C.L.
        • Visco A.G.
        • Siddiqui N.Y.
        Treatment for urinary tract infection after midurethral sling: a retrospective study comparing patients who receive short-term postoperative catheterization and patients who pass a void trial on the day of surgery.
        Female Pelvic Med Reconstr Surg. 2012; 18: 175-178
        • Trautner B.W.
        • Darouiche R.O.
        Catheter-associated infections: pathogenesis affects prevention.
        Arch Intern Med. 2004; 164: 842-850
        • Elkadry E.A.
        • Kenton K.S.
        • FitzGerald M.P.
        • Shott S.
        • Brubaker L.
        Patient-selected goals: a new perspective on surgical outcome.
        Am J Obstet Gynecol. 2003; 189: 1551-1558
        • Foster Sr., R.T.
        • Borawski K.M.
        • South M.M.
        • Weidner A.C.
        • Webster G.D.
        • Amundsen C.L.
        A randomized, controlled trial evaluating 2 techniques of postoperative bladder testing after transvaginal surgery.
        Am J Obstet Gynecol. 2007; 197: 627.e1-627.e4
        • Dieter A.A.
        • Amundsen C.L.
        • Edenfield A.L.
        • et al.
        Oral antibiotics to prevent postoperative urinary tract infection: randomized controlled trial.
        Obstet Gynecol. 2014; 123: 96-103
        • Ingber M.S.
        • Vasavada S.P.
        • Moore C.K.
        • Rackley R.R.
        • Firoozi F.
        • Goldman H.B.
        Force of stream after sling therapy: safety and efficacy of rapid discharge care pathway based on subjective patient report.
        J Urol. 2011; 185: 993-997
        • Uebersax J.S.
        • Wyman J.F.
        • Shumaker S.A.
        • McClish D.K.
        • Fantl J.A.
        Short forms to assess life quality and symptom distress for urinary incontinence in women: the incontinence impact questionnaire and the urogenital distress inventory; continence program for women research group.
        Neurourol Urodyn. 1995; 14: 131-139
        • Sandvik H.
        • Hunskaar S.
        • Seim A.
        • Hermstad R.
        • Vanvik A.
        • Bratt H.
        Validation of a severity index in female urinary incontinence and its implementation in an epidemiological survey.
        J Epidemiol Community Health. 1993; 47: 497-499
        • Charlson M.E.
        • Pompei P.
        • Ales K.L.
        • MacKenzie C.R.
        A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.
        J Chronic Dis. 1987; 40: 373-383
        • Price D.D.
        • McGrath P.A.
        • Rafii A.
        • Buckingham B.
        The validation of visual analogue scales as ratio scale measures for chronic and experimental pain.
        Pain. 1983; 17: 45-56
        • McCarthy Jr., M.
        • Jonasson O.
        • Chang C.H.
        • et al.
        Assessment of patient functional status after surgery.
        J Am Coll Surg. 2005; 201: 171-178
        • Richter H.E.
        • Albo M.E.
        • Zyczynski H.M.
        • et al.
        Retropubic versus transobturator midurethral slings for stress incontinence.
        N Engl J Med. 2010; 362: 2066-2076
        • Harmanli O.
        • Boyer R.L.
        • Metz S.
        • Tunitsky E.
        • Jones K.A.
        Double-blinded randomized trial of preoperative antibiotics in midurethral sling procedures and review of the literature.
        Int Urogynecol J. 2011; 22: 1249-1253