Pathophysiology of female Urinary Incontinenceand Pelvic Organ
Prolapse
Chung Shan Medical University Department of OB/GYN,
Chung Shan Medical University Hospital
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The functional relationship of urethral and bladder smooth muscle
to the pelvic floor muscle --1
During bladder neck opening: • The superficial trigone extends
from
bladder base to the external urethral meatus
Trigone is stretched backwards by the backward extension of the
vagina (through nerve endings in bladder base)
proximal urethra is actively opened out like a trapdoor,
“funnelling”
sharply dropping the urethral resistance
urine flow (urinate)
Petros PE and Ulmsten U. An integral theory of female urinary
incontience. Acta Obstet Gynecol Scand 1990 69 (suppl 153):
7-31
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The functional relationship of urethral and bladder smooth muscle
to the pelvic floor muscle --2
Closure function: • The superficial trigone contracts cresta
urethralis be pulled upwards by forward contraction of PCM closing
off the urethra
• Tension of the pubovesical ligament is important for the
“kinking” mechanism of bladder neck closure.
• Laxity in the vagina or its supporting ligaments may not allow
the semi- circular smooth muscle sphincters to function
efficiently. urine leakage
Petros PE and Ulmsten U. An integral theory of female urinary
incontience. Acta Obstet Gynecol Scand 1990 69 (suppl 153):
7-31
The functional relationship of bladder, urethra, vagina, spinal
cord, and brain.
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Pubovesical ligaments • Bands of sm. m. • Continuous with the
detrusor m. • Is appropriately called the pubovesical m. and makes
up
bulk of the pubovesical ligament. • the attachment of these fibers
primarily to the arcus
tendineus fasciae pelvis rather than the pubic bones.
• these tissues are not suited to provide urethral support, but the
active opening of the vesical neck seen at the onset of
micturition
---DeLancey JOL Neurourology and urodynamics 1989; 8: 53-61.
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Pubourethral ligament defect --- Petros & Ulmsten Scand J Urol
Nephrol 1993 (suppl 153): page 19-20.
• Laxity of the pubourethral ligament (PUL) may be congenital,
occur due to advanced age (collagen loss) or childbirth.
• This defect may cause both urethral and bladder neck closure
mechanism inactivated.
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Vaginal hammock -- Petros PE and Ulmsten U. An integral theory of
female urinary incontience. Acta Obstet
Gynecol Scand 1990 69 (suppl 153): 7-31
• The concept of forward action of pubococcygeus (PCM) on the
hammock.
• The forward movement of the PCM-vaginal hammock complex is the
prime factor in closing off the urethra.
• Urethral closure is effected from behind the posterior urethral
wall. In contrast, if closure was effected by raised intraabdominal
pressure, then the compression of the urethral canal would be from
in front, not from behind.
---Pap petros PE and Ulmsten U. Neurourol Urodyn 1995; 14:
337-350.
Hammock theory --- DeLancey JOL 1994 versus
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• Twisting of the urethra --- Edwards L 1971
• Integral theory --- Petros &Ulmsten 1990
• Hammock theory --- DeLancey JOL 1994
• Weak pelvic floor muscles --- Payne CK 2000
• Mid-urethra sling --- since Nilsson 2001
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The effect of vaginal parity on the development of urinary
incontinence and pelvic organ prolapse
Rortveit et al. N Engl J Med 2003; 348: 900-907 Mant et al. BJOG
1997; 104: 579-585
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Effects of childbirth on pelvic floor ---Petros & Ulmsten Scand
J Urol Nephrol 1993 (suppl 153): page 21.
• Passage of fetal head damage to the motor end plate
(neuromuscular junction) of the pelvic floor muscle, the vaginal
connective tissue, or both.
then, loss of muscle tone
• It may be due to degeneration of nerves by direct stretch, torn,
or interrupt of blood supply from intercommunicating vascularity of
nerves
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Childbirth Direct • Damage to pelvic soft tissues • Disruption of
the endopelvic
fasciae • Injury to the vaginal walls
Indirect • a result of damage to the
muscles and nerves of the pelvic floor
Nerve damage due to • Pudendal and perineal nerve
injury • Direct compression of nerves or
stretching of nerves • interrupt of blood supply from
intercommunicating vascularity of nerves
Meyer et al. Obstet Gynecol 1998;92: 613-618
Peschers et al. BJOG 1997; 104: 1004-1008. Snooks et al. Lancet
1984; 2: 546-550. Smith et al. BJOG 1989; 96: 24-48. Dolan et al.
BJOG 2003; 110:1107-1114
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Pelvic floor damage & pudendal nerve dysfunction after
childbirth
• Vaginal delivery causes partial denervation of the pelvic floor
(with consequent re-innervation) in most women having their first
baby.
• Women with SUI (n=87, control = 42) had delayed conduction to
both the striated urethral muscles and the pelvic floor muscle,
indicative of denervation injury.
• 146 women were examined during pregnancy and 12 week post partum
with measurement of pudendal nerve terminal motor latency
(PNTML)
• PNTML increases in both primiparous and multiparous women after
delivery. In 10% of the women the increase resulted a pathologic
PNTML value > 2.4 msec.
• The PNTML was significantly associated with age, the occurrence
of pelvic instability and the use of vaccum extraction.
• The group of women with urinary incontinence had a significant
increased PNTML.
-- Tetzschner T et al. (Denmark) Acta Obstet Gynecol Scand 1997;
76: 324-331.
- Allen RE et al. (UK). Br J Obstet Gynecol 1990; 97: 770-
779.
Smith ARB et al. (UK) Br J Obstet Gynecol 1989; 96: 29-32.
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• Estrogen deficiency – Tissue irritation – Urge symptoms –
Atrophic mucosal and submucosal changes poor coaptation
Norton et al. Neurourol Urodyn 1992; 11: 2-4. Norton et al. Clin
Obstet Gynecol 1993; 36: 927
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403. Why do black African Women have reduced incidence of stress
incontinence compared with African Women? Labrda E et al. UK IUGA
2006
Conclusion: • Differences in connective tissue between races.
• Black women: higher collagen III, lower collagen I:III ratio,
more elastic.
• Higher collagen XVII expression: a higher cell adhesion (protect
the tissue from breakdown)
• The connective tissue constituents of black women appear more
appropriately designed to cope with continual pelvic floor strain.
(receiving an insult and compensate for the stress)
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Mechanism of Support and Prolapse
How to maintain the pelvic organ in the pelvic cavity •
Constriction () --- outlet • Suspension () --- ligament and
endopelvic fascia • Flap-valve closure () --- levator plate and
genital hiatus
““BoatBoat--inin--dry dockdry dock”” ------ Norton P. 90sNorton P.
90s’’
20Female pelvic floor disorders- investigation and management
Edited by J. Thomas Benson, 1992, Fig 1-12, p12
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• Felt-like meshwork (fibrous tissue, sheets of fibroareolar
tissue)
• Cardino-uterosacral lig. complex, pubocervical fascia.
• Rectovaginal septum (Denonvilliers’ fascia), periurethral fascia
(Raz), urethropelvic lig. (Raz).
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Etiologies of pelvic floor dysfunction (Pelvic Organs
Prolapse)
• The position of a pelvic viscus immediately supported by smooth
muscle, blood vessels, collagen and elastic tissue. Smith ARB et al
Br J Obstet Gynecol 1989; 96: 24-28
• In healthy nulliparous women in the erect position the vaginal
axis is close to horizontal and that the pelvic viscera are
supported by the levator plate. (Berglas & Rubin 1953)
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Etiologies of pelvic floor dysfunction (Pelvic Organs
Prolapse)
• Levator plate sags inclining the axis of the vagina towards the
vertical and widening the introitus increase the strain on the
so-called fascia supports of the pelvic viscera
• Summation of anatomic defect, connective tissues damage and
neurological degeneration --- Carry-over effect
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Defects in the apical support Include: • The loss of
cardinal/uterosacral support with resultant
cervical/uterine or vaginal cuff descent
• The detachment of the fibromuscular vagina from the anterior
rectum with resultant enterocele or, at times, sigmoidocele into
the rectovaginal space
• Tears or attenuation of the upper fibromuscular tissue, usually
after hysterectomy, leading to a central apical descent that
frequently presents as a ballooning defect
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• Tears or attenuation of the vaginal fibromuscular wall
• Detachment from the pelvic walls, the cervix or cardinal ligament
complex, or from the pubis
• Specific sites of fibromuscular tears are frequently difficult to
recognize (lateral, apex, or central)
DeLancey JOL. Am J Obstet Gynecol 2002; 187: 93-98.
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Defects of the support for the rectum and posterior vagina
• Rectocele – Discrete tears in the
Denonvillier’s fascia at its lateral, apical, and perineal
attachments and centrally within the fascia itself.
• Perineal rectocele (difficulty with defection) – Perineal
detachment, along
with a defect in the perineal membrane
Attachment of the rectovaginal septum to the pelvic sidewall
Leffler KS. Am J Obstet Gynecol 2001; 185: 41-43
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Heavy lifting
Bent AE Ostergard’s Urogynecology and Pelvic Floor Dysfunction, 5th
ed, pp43-50
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Etiologies of pelvic floor dysfunction How to repair? (Pelvic
Organs Prolapse)
The last straw breaks the camel’s back.
• Which factor is the last straw that will break the camel’s back ?
--- add-on, carry-over effect, summation…..
• Taking out the last straw from the camel’s back, is it enough? or
to fix the broken back bone or broken leg?
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• Individualize • Site-specific • Function ?
– Do we really restore the function? – Or restore the functional
position ? – Mesh or not mesh? – Postoperative care (mandatory !!!)
: – Early ambulation or not? – Re-gluing - be glued
(fibrosis)
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Any question?
Pelvic Floor Dysfunction
The functional relationship of urethral and bladder smooth muscle
to the pelvic floor muscle --1
The functional relationship of urethral and bladder smooth muscle
to the pelvic floor muscle --2
Pubovesical ligaments
Pubourethral ligament defect --- Petros & Ulmsten Scand J Urol
Nephrol 1993 (suppl 153): page 19-20.
Vaginal hammock-- Petros PE and Ulmsten U. An integral theory of
female urinary incontience. Acta Obstet Gynecol Scand 1990 69
(suppl 153): 7-31
Theory of urinary incontinence
Effects of childbirth on pelvic floor ---Petros & Ulmsten Scand
J Urol Nephrol 1993 (suppl 153): page 21.
Childbirth
Connective tissue disorders
403. Why do black African Women have reduced incidence of stress
incontinence compared with African Women? Labrda E et al. UK IUGA
2006
Pelvic Floor Dysfunction
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Endopelvic fasciae
Defects in the apical support
Defects in the support structure for the anterior compartment
Defects of the support for the rectum and posterior vagina
Predisposing factors
Etiologies of pelvic floor dysfunction How to repair? (Pelvic
Organs Prolapse)
How to restore the mechanism of support ?
Thank you for your attention