Hypothesis / aims of study
Stress urinary incontinence (SUI) is the involuntary leakage of urine during activities like coughing, occurring when bladder pressure exceeds the urethra's ability to stay sealed. It affects 20-40% of individuals, significantly impacting physical, mental, and social well-being. Since 1980, the European Association of Urology (EAU) has endorsed ultrasound to evaluate urinary incontinence and the pelvic floor. Key parameters include bladder neck descent (BND), UH, urethral funneling, bladder neck internal angle (BIA), α angle, β angle, and their deviations, measured at rest and during the Valsalva maneuver. These parameters help diagnose SUI, though research lacks a standardized methodology, and findings remain inconsistent. Thus, physical examination remains central to diagnosis. This study aims to determine if ultrasound parameters are linked to SUI symptom severity.
Study design, materials and methods
This study was conducted at a single medical center with 76 women, including 38 with SUI. The control group, matched for age and parity, consisted of healthy women without urinary incontinence. Participants were grouped based on the presence of SU. Ultrasound was performed in the standard gynecological examination position with full bladder. Parameters such as the α angle, BIA, and β angle were measured. For subsequent tests, the same position and bladder volume were maintained to measure bladder neck funneling (BNF), bladder neck symphyseal distance (BSD), bladder neck descent (BND), urethral length (UL), and the diameter of the proximal urethra (UD), as well as the pubo-urethral distance (PUD). All parameters were assessed at rest and during the Valsalva maneuver (VM). At the end of the study, post-void residual urine (PVR) was measured after the patient voided.
Results
A total of 76 women participated in the study, with 38 in the main group and 38 in the control group.
Regarding changes in US parameters within groups, 73.6% (n=28) of SUI patients showed significant urethral shortening in the VM, while no such changes were found in the control group. PUD, as an indicator of urethral hypermobility, was not significantly different between the groups, although an increase was observed in almost half of the SUI group (n=20; 52.6%) and to a lesser extent in the control group (n=17; 44.7%). The α angle increased significantly after VM in most of the SUI group (n=20; 76.3%) and in the control group (n=22; 57.8%). The RVA significantly decreased only in the SUI group (n=26; 38.4%). According to the ICIQ-SF, patients were distributed as follows: no patients with slight severity, Grade 2 (moderate severity) – n=8 (21.01%), Grade 3 (severe) – n=22 (57.8%), and Grade 4 (extremely severe) – n=8 (21.01%). No significant differences in UT parameters were found concerning the severity of symptoms, either at rest or in VM.
Interpretation of results
UD in the proximal urethra, measured during VM, was useful for differentiating urinary incontinence and may indicate internal sphincter deficiency (ISD). While no significant changes were seen at rest in the SUI group, UD was significantly higher during VM in the SUI group compared to the control. PUD, reflecting mid-urethra mobility, was significantly higher in the SUI group at both rest and during VM. The α and β angles, commonly used in SUI studies, were significantly higher in the SUI group at both rest and during VM, with a greater α angle deviation. No significant differences in the β angle were found, indicating bladder neck immobility in the SUI group.