Hypothesis / aims of study
The performance of a urodynamics (UDS) in the preoperative assessment of female stress urinary incontinence (SUI) is a controversial topic. European guidelines and NICE guidelines recommend against routinely performing UDS prior to treatment for uncomplicated SUI (1, 2). However, it is estimated that there is a low percentage of patients with uncomplicated SUI (3).
Our objective is to examine the percentage of patients with uncomplicated SUI among those undergoing surgical treatment with the placement of a transobturator tape (TOT) in our center, as well as to describe the findings of preoperative urodynamics (UDS).
Study design, materials and methods
This is a retrospective descriptive observational study in which we reviewed patients who underwent TOT surgery for SUI in our center between 2018 and 2023. In the preoperative assessment, a complete medical history was obtained, including the medical-surgical history of patients, and a neuro-urological physical examination with the patient in supine position. In cases where UDS was performed, it was carried out according to the Good Urodynamic Practice Guidelines of the International Continence Society.
Exclusion criteria were neurological disease, history of pelvic surgery, or pelvic radiotherapy.
Results
Of the patients who underwent TOT surgery for SUI in our center between 2018 and 2023, 128 met the criteria for the study. The mean age (SD, standard deviation) of the patients was 58.25 (12.9), with a median (SD) of vaginal deliveries of 2 (1.37). 16 (12.5%) patients were diabetic and 87 (68%) were postmenopausal. The mean body mass index (SD) was 30.23 (7.32).
Only 41 (32%) patients met the criteria for uncomplicated SUI. 86 (67.2%) patients reported urgency, 63 (49.2%) had urgency urinary incontinence (UUI), and 5 (3.9%) reported voiding symptoms.
During the physical examination, urethral hypermobility was observed in 73 (57%) patients, and stress leakage was demonstrated in 87 (68%) of the patients.
Of the 128 patients in the study, 94 (73.4%) had UDS prior to surgery. UDS findings were urodynamic SUI in 70 (74.5%) patients, detrusor overactivity in 30 (31.9%), bladder hypersensitivity in 3 (3.2%), reduced compliance in 2 (2.1%), detrusor underactivity in 4 (4.3%) of which significant post-void residual volume (PVR) (>100ml) was present in 1 (1.1%) patient. Uncomplicated urodynamic SUI was present in 48.9% of patients. The mean PVR (SD) was 8.16 ml (23.84), with only 1 (1.1%) patient having a residual volume greater than 100 ml.
In 24 (25.5%) patients no SUI was demonstrated during UDS. Stress leakage was demonstrated during physical examination but not during UDS in 22 (23.4%) patients. Stress leakage was not demonstrated during examination but was during UDS in 12 (12.8%) patients.
Interpretation of results
In our analysis, the prevalence of uncomplicated SUI was 32% based on medical history and physical examination, while it was 49% based on UDS. While our data on uncomplicated UDS are higher than those described in other series, being a retrospective series of patients selected for surgery may introduce a bias that could explain these differences. Likewise, these results suggest that uncomplicated SUI is relatively uncommon, meaning that only a small percentage of patients might avoid undergoing UDS before considering surgery for SUI. When analyzing urodynamic results, we observed that 31.9% of cases had detrusor overactivity. Some studies have suggested that this finding may be a risk factor for worse outcomes after surgery, which should be considered in managing patient expectations. Only 4 patients showed parameters of detrusor underactivity, and 1 had a significant post-void residual; therefore, surgery might have been discouraged for patients presenting these findings. It is important to have as much information as possible to advise patients on the most appropriate treatment for their urinary incontinence problem.