Clinical Anatomy of the Female Pelvis
Floor of Pelvis
three perforations in floor of pelvis (
urethra, vagina, rectum
) lead to potential weakness
anatomy was designed for quadrupeds
Þ
upright posture places a tremendous strain on the pelvic floor
Most pelvic floor abnormalities are surgically correctable.
Childbirth
causes tears in fascia and muscle wall, and can result in:
Cystocele –
herniation of bladder into the anterior wall of the vagina
Rectocele –
herniation of anterior wall of the rectum into the posterior wall of the vagina
Enterocele
– herniation of small bowel
Uterus
Prolapse –
herniation of uterus; anatomic position of uterus can make the uterus more or less prone to prolapse
Incontinence
>50 % of women over 60 suffer from incontinence – related to defects in pelvic wall caused during childbirth
bladder is weakly attached to pubic symphysis and attachment is easily damaged
this can lead to
sagging
of base of the bladder and
voiding dysfunction
Urine Flow
with normal urine flow, voiding should take about
20 seconds
, flow rate should follow a
smooth bell shaped curve
abnormal flow depicted by changes in rate or pattern
if bladder falls below urethral opening
Þ
frequent urination without complete bladder emptying
Evaluation of urine flow
– catheter in vagina, bladder and urethra to obtain pressure
subtract abdominal pressure from measured vagina, bladder and urethra pressure to obtain true pressure measurement
Voiding
– occurs when
detrussor muscle
(a smooth muscle) is contracted and sphincter is relaxed
the detrussor muscle contracts when stretched, but urination is usually prevented by contraction of the sphincter, which is under voluntary control
Þ
decreased control of sphincter can lead to incontinence
Þ
Detrussor Instability
detrussor instability is often caused by a cystocele
Genuine Stress Incontinence
no contraction of detrussor, but loss of sphincter control
causes uncontrolled loss of small volumes of urine with coughing, sneezing or movements; worsens over time
only small volumes are lost due to compensation by striated muscle
often related to childbirth; can improve with correct hormone environment, worsens after menopause (loss of hormones)