Levator function and voluntary augmentation of maximum urethral closure pressure.

Area of Science:

• Urogynecology
• Pelvic Floor Disorders
• Female Lower Urinary Tract Symptoms

Background:

• Pelvic floor dysfunction affects many women, potentially leading to urinary incontinence.
• Maximum urethral closure pressure (MUCP) is a key indicator of urethral function.
• The ability to voluntarily augment MUCP using pelvic floor muscle contraction (PFMC) is not fully understood in relation to pelvic floor muscle structure.

Purpose of the Study:

• To determine if women with pelvic floor dysfunction symptoms can augment MUCP via PFMC.
• To investigate the association between MUCP augmentation and the structure and function of the levator ani muscle.

Main Methods:

• 300 women underwent multichannel urodynamic testing and 4D pelvic floor ultrasound.
• MUCP was measured at rest and during directed PFMC.
• Levator ani muscle strength (Modified Oxford Grading) and integrity (ultrasound) were assessed.

Main Results:

• Mean MUCP increased from 36 cm H2O at rest to 42 cm H2O during PFMC (approx. 20% augmentation).
• A significant positive correlation was found between levator muscle contraction strength (MOS) and MUCP augmentation (r=0.24, P=0.001).
• Women with intact levator muscles demonstrated more effective MUCP augmentation (P=0.038).

Conclusions:

• Symptomatic women can voluntarily augment their urethral closure pressure.
• The degree of MUCP augmentation is positively associated with levator muscle contractility.
• Levator muscle avulsion is negatively associated with the ability to augment MUCP.