The rates reported for postoperative urinary retention following midurethral sling procedures are highly variable. Determining which patients have a higher likelihood of failing a voiding trial will help with preoperative counseling prior to midurethral sling.
To identify preoperative predictors for failed voiding trial following isolated midurethral sling.
A retrospective multicenter case-control study was performed by including all isolated midurethral sling procedures performed between 1/1/10 to 6/30/15 at six academic centers. We collected demographics, medical and surgical histories, voiding symptoms, urodynamic evaluation, and intraoperative data from the medical record. We excluded patients not eligible for attempted voiding trial after surgery (e.g. bladder perforation requiring catheterization). Cases failed a postoperative voiding trial and were discharged with an indwelling catheter or taught intermittent self-catheterization; controls passed a voiding trial. We also recorded any adverse events such as urinary tract infection or voiding dysfunction up to six weeks after surgery. Bivariate analyses were completed using Mann-Whitney and Pearson chi-square as appropriate. Multivariable stepwise logistic regression was used to determine predictors of failing a voiding trial.
464 patients had an isolated sling (70.9% retropubic, 28.4% transobturator, 0.6% single-incision); 101 (21.8%) failed the initial voiding trial. At follow-up visits, 90.4% passed a second voiding trial, and 38.5% of the remainder passed on third attempt.
Prior prolapse or incontinence surgery was similar in cases vs controls (31% vs 28%, p=0.610) as were age, race, body mass index, and operative time. Significantly more of the cases (32%) than controls (22%) had a Charlson comorbidity index score of 1 or greater (p=0.039). Overactive bladder symptoms of urgency, frequency, and urgency incontinence were similar in both groups as was detrusor overactivity in those with urodynamic evaluation (29% vs 22%, p=0.136), but nocturia was reported more in the cases (50% vs 38%, p=0.046). Mean (SD) bladder capacity was similar in both groups [406(148) mL vs 388(122) mL, p=0.542] as was max flow rate with uroflowmetry and pressure flow studies. Cases were significantly more likely to have a voiding type other than detrusor contraction: 37% vs 25%, p=0.027, OR 1.79 (95% CI: 1.07-3.00). There was no difference in voiding trial failures between retropubic and transobturator routes (23.1% vs 18.9%, p=0.329). Within 6 weeks of surgery, the frequency of urinary tract infection in cases was greater than controls [20% vs 6%, p<0.001; OR 3.51 (1.82-6.75)]. After passing a repeat voiding trial, cases were more likely to present with acute urinary retention [10% vs 3%, p=0.003; OR 4.00 (1.61-9.92)].
Increasing Charlson Comorbidity Index increased risk of voiding trial failure; apart from this, we did not identify other demographic information among patients who did not undergo urodynamic evaluation that reliably forecasted voiding trial failure.
The majority of women will pass a voiding trial on first attempt after isolated midurethral sling. Current medical comorbidities are predictive of voiding trial failure while other demographic/exam findings are not. Patients failing the initial voiding trial are at increased risk of postoperative urinary tract infection or developing acute retention after passing a subsequent voiding trial.
American journal of obstetrics and gynecology. 2016 Jun 16 [Epub ahead of print]
Christopher M Ripperda, Joseph T Kowalski, Zaid Q Chaudhry, Aman S Mahal, Jennifer Lanzer, Nabila Noor, Meadow M Good, Linda S Hynan, Peter C Jeppson, David D Rahn
Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX, United States. Electronic address: ., Department of Obstetrics and Gynecology, University of Iowa, Iowa City, IA, United States., Department of Obstetrics and Gynecology, University of California, Los Angeles, Los Angeles, CA, United States., Department of Obstetrics and Gynecology, Stanford University, Palo Alto, CA, United States., Department of Gynecology and Obstetrics, Emory University, Atlanta, GA, United States., Department of Obstetrics and Gynecology, Mount Auburn Hospital/Harvard Medical School, Cambridge, MA, United States., Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX, United States., Department of Clinical Sciences - Division of Biostatistics, Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, United States., Department of Obstetrics and Gynecology, University of New Mexico, Albuquerque, NM, United States., Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, TX, United States.