Structural aspects of the extrinsic continence mechanism

Area of Science:

• Anatomy
• Urology
• Pelvic Floor Physiology

Background:

• Urethral pressure changes during coughing and at rest suggest extrinsic structures influence sphincteric function.
• Previous studies indicated a link between urethral pressure dynamics and structures beyond the urethra itself.

Purpose of the Study:

• To investigate the anatomical structure of the extrinsic continence mechanism.
• To correlate observed anatomical structures with physiological measurements of urethral pressure.

Main Methods:

• Histological examination of serial sections from eight female cadavers.
• Dissection of 34 female cadavers to analyze pelvic viscera and surrounding structures.

Main Results:

• The anterior vaginal wall attaches to the pelvic diaphragm muscles and arcus tendineus fasciae pelvis, influencing proximal urethral support.
• Striated muscle arches (compressor urethrae, urethrovaginal sphincter) over the distal urethra may cause pressure increases during coughing.
• These attachments and muscles provide both resting support and dynamic compression to the urethra.

Conclusions:

• Understanding the extrinsic continence mechanism's anatomy clarifies urethral pressure variations during cough and at rest.
• These anatomical insights are crucial for understanding stress incontinence and potential reasons for surgical intervention failures.