Is there a correlation between levator ani and urethral sphincter complex status on 3D ultrasonography?

To determine the correlation between levator ani deficiency (LAD) and urethral sphincter complex measurements as visualized on 3D endovaginal ultrasonography, and to compare the LAD score with continence status.

This was a retrospective analysis of patients seen at our institution between January 2011 and August 2013. Patients were dichotomized into those with urodynamic stress urinary incontinence (SUI) and those with no SUI. Levator ani status was evaluated using a validated scoring system yielding scores of 0 - 6 (normal levator ani/mild LAD), 7 - 12 (moderate LAD), and 13 - 18 (severe LAD). The length, horizontal diameter, and cross-sectional area of the urethra, and the length, width, and the area of the rhabdomyosphincter and smooth muscle sphincter were likewise measured using 3D ultrasound volumes.

Of the 80 patients included, 54 (67.5%) had SUI and 26 (32.5%) were continent. 18 (22.5%) had evidence of mild LAD, 54 (67.5%) had moderate LAD, and 8 (10.0%) had severe LAD. Among patients with SUI, those with normal levator ani muscles or mild LAD had greater urethral smooth muscle width than those with moderate and severe LAD (p = 0.0238). A greater proportion of patients with SUI also had moderate to severe LAD than continent patients (p = 0.0177, OR 3.59, 95% CI 1.21 - 10.65). There was no difference in LAD distribution by type of stress incontinence (presence or absence of intrinsic sphincter deficiency; p =  .2377).

LAD and urethral sphincter complex status, as visualized on 3D ultrasonography, are independent factors. Moderate to severe LAD is more prevalent in patients with SUI.