Transperineal Ultrasonography in Stress Urinary Incontinence
Condition: Stress Urinary Incontinence
MeSH terms: Urinary Incontinence; Enuresis; Urinary Incontinence, Stress
Study type: Observational

Summary: 
      Pelvic organ prolapse (POP) and urinary incontinence (UI) are common female disorders.
      Accurate diagnosis of the aetiology of pelvic organ descent and prolapse with or without
      accompanying urination disorders is essential for appropriate therapeutic management. Imaging
      and functional urodynamic testing are being increasingly used in the diagnosis of this
      pathology, because precise assessment of the damage to the supporting and ligament apparatus
      is essential for therapeutic success. Pelvic floor ultrasound can facilitate dynamic
      assessment of static changes that occur during functional tests. Such assessments can provide
      additional insights into existing defects, which have explorative value and allow for
      targeted correction of damage, and may thus indirectly contribute to reduced rates of
      revision surgeries.
    

Detailed description: 
      Application of the ultrasound transducer to the patient's perineum can visualise three female
      pelvic compartments, and the images can be frozen to assess the positions of anatomical
      structures in relation to the pelvic bones and the pre-set planes as well as measure their
      mutual distances and predefined angles.

      The aim of the study was to assess the utility of ultrasound in the detection of UI,
      particularly for establishing the most useful anatomical and functional parameters and to
      propose cut-off points for ultrasonographic parameters. The presence of stress urinary
      incontinence (SUI) requiring surgical management was the inclusion criterion. All patients
      underwent transperineal ultrasound (TPU) with a Voluson E6 (GE Medical systems, Milwaukee,
      WI, USA). The probe was oriented to coaxially visualise the pubic symphysis on one side and
      the anus and rectum on the other side of the 2D image. When all three compartments could not
      be visualised in one image, one image showing the anterior and medial compartments and
      another image showing the medial and posterior compartments were obtained instead. Next,
      3D/4D ultrasound was performed to obtain an image in the coronal plane at the level of the
      arms of the levator ani muscle, showing the pubic symphysis and the anus. All measurements
      were performed in three states: during pelvic muscle relaxation, during Valsalva manoeuvre,
      and during perineal squeezing. The following quantitative parameters were assessed and
      compared across two arms of the study (with and without SUI):

        -  Bladder-symphysis distance (BSD) - measured as the distance between the urine bladder
           neck and the symphysis,

        -  Alpha angle - the angle between the axis of the proximal urethra and the x-axis of the
           symphysis pubis (central line),

        -  Beta angle - the angle between the line parallel to the proximal urethra and the line
           parallel to the distal axis of urethra,

        -  Gamma angle - the angle between the lower margin of the symphysis pubis and the urinary
           bladder neck),

        -  Retrovesical angle (RVA) - the angle between the axis of the proximal urethra and the
           tangent line to the lowest part of the posterior wall of the urinary bladder,

        -  Mean urethral diameter - the sum of the urethral diameters at three points (proximal,
           central, and distal parts) divided by 3.
    

Intervention name(s): Transperineal ultrasonography
Intervention type(s): Diagnostic Test
Intervention description(s): Transperineal ultrasound (TPU) with a Voluson E6 (GE Medical systems, Milwaukee, WI, USA). The probe was oriented to coaxially visualise the pubic symphysis on one side and the anus and rectum on the other side of the 2D image. Next, 3D/4D ultrasound was performed to obtain an image in the coronal plane at the level of the arms of the levator ani muscle, showing the pubic symphysis and the anus. All measurements were performed in three states: during pelvic muscle relaxation, during Valsalva manoeuvre, and during perineal squeezing.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Women hospitalised at the Clinical Department of Gynecological Oncology and Gynecology,
        University Hospital in Krakow, between July 2012 and July 2015, aged over 18 years. The
        presence of stress urinary incontinence (SUI) requiring surgical management was the
        inclusion criterion. The control group included patients without UI referred for surgery
        due to mild gynaecological disorders. Exclusion criteria included prior surgery for either
        UI or POP, pelvic tumours that could affect pelvic organ statics, and lack of informed
        consent to participate in the study.
      
Keywords: stress urinary incontinence, transperineal ultrasound