Introduction and hypothesis: We noninvasively compared urinary flow in both pre- and post-transobturator tape (TOT) procedures in stress urinary incontinence (SUI) patients using previously reported corrected flow-age nomograms in healthy women.
Methods: This retrospective cohort study included patients who underwent a successful TOT procedure to treat SUI. Non-instrumented uroflowmetry was performed before and 3 months after surgery. Corrected maximum flow rate (cQmax) and average flow rate (cQave) were calculated using Qmax/√voided volume (VV) and Qave/√VV respectively. The ratio of corrected flow to age-adjusted corrected flow in healthy women was calculated in each patient. Each parameter was compared against pre-TOT and 3-months post-TOT values.
Results: Sixty-two patients were eligible for study inclusion. All urinary flow parameters were significantly higher pre-TOT than at 3 months post-TOT. The number of patients with cQmax and cQave over mean flow-age nomogram, compared with healthy women, before the TOT procedure decreased 3 months post-TOT; however, in many patients, cQmax and cQave were higher than in the corrected flow-age nomogram post-TOT. No significant difference in the ratio of cQmax to age-adjusted cQmax between pre- and post-TOT in the normal urinary flow group was observed, but significantly decreased in the high urinary flow group 3 months after TOT.
Conclusions: Urinary flow rates were higher in SUI patients compared with age-matched controls and successful TOT procedures normalized urinary flows in patients with high urinary flow. A simple evaluation of urinary flow using a corrected flow-age nomogram may be clinically useful in SUI patients.
Keywords: Corrected flow–age nomogram; Stress urinary incontinence; Urinary flow rate.