Levator ani defects in patients with stress urinary incontinence: three-dimensional endovaginal ultrasound assessment

To determine the prevalence of levator ani (LA) muscle subdivision defects in patients with SUI using three-dimensional endovaginal ultrasound (3D EVUS).

This is a prospective cohort study of 100 patients with pure or predominant urodynamic SUI who underwent 3D EVUS. The 3D cubes obtained were analyzed and the LA muscle was divided into three subgroups: the puboperinealis/puboanalis, the puborectalis, and the iliococcygeus/pubococcygeus. Each LA muscle subdivision was individually scored on each side (0: no defect, 1: ≤50 % muscle loss, 2: > 50 % muscle loss, and 3: total absence of the muscle) and a cumulative score, categorized as 0 (no defect), mild (total score 1–6), moderate (7–12), and severe (≥13) was calculated.

The number of women with no LA muscle defect or a mild defect was significantly higher than the number of those with a moderate or severe defect (p < 0.001). Apart from the small inverse relationship of the total puborectalis muscle score and the cumulative subdivision score with maximal urethral closure pressure (r value > −0.3; p < 0.05), the muscle defect scores were not found to correlate with urodynamic parameters (p > 0.05). Although all muscle subdivisions contributed to the overall LA muscle defect score, the association was strongest for the puborectalis component (r = 0.9; p < 0.001). The prevalence of the LA muscle defect in patients with intrinsic sphincter deficiency (ISD) was not significantly different from that in patients without ISD.

Patients with SUI have a higher prevalence of no or mild LA defect compared with a moderate or severe LA defect.