Pelvic floor ultrasound versus urodynamics in evaluating insensible urinary incontinence: A retrospective study

Insensible Urinary Incontinence (IUI) is a situation when you complain of urinary incontinence but are unaware of how it occurred. Therefore, it is necessary to apply highly specific diagnostic methods to promote accuracy in the diagnosis of IUI, including pelvic floor ultrasound (PFU) and urodynamic studies (UDS).

A total of 41 women with IUI were retrospectively included. Patients were categorized into two groups: the urodynamic urinary incontinence group (UUI group, n=20) and the non-urodynamic urinary incontinence group (NUUI group, n=21), according to the urine leakage during UDS. The baseline clinical characteristics, UDS results, and PFU parameters were collected.

Compared with the NUUI group, the UUI group had a smaller maximum cystometric capacity (P=0.008), lower maximum urethral closure pressure (P=0.005), shorter functional urethral length (FUL) (P=0.01), more bladder neck funneling (BNF) (P=0.02), greater BNF depth (P=0.04), and larger BNF area (P=0.01). The area and depth of BNF were negatively correlated with maximum urethral closure pressure (r=-0.42, P=0.01), FUL (r=-0.36, P=0.02 versus r=-0.39, P=0.01), and maximum cystometric capacity (r=-0.35, P=0.03), but positively correlated with maximum urinary flow rate (r=0.33, P=0.04 versus r=0.36, P=0.02). The canonical correlation analysis of the ultrasound parameters and UDS parameters shows that the first pair of canonical variables was statistically significant (r1=0.9, P<0.001).

The PFU is associated with UDS in evaluating IUI. It has the advantages of low cost and high comfort, thus should be used as an auxiliary examination for IUI.