Anatomy of Urinary Incontinence and Prolapse Flashcards
What separates the pelvic cavity from the perineum?
The pelvic floor
What does the pelvic floor play an important role in?
Providing support to pelvic organs and maintaining continence
What are the three layers of the pelvic floor?
Pelvic diaphragm, muscles of perineal pouches, perineal membranes
What is the deepest layer of the pelvic floor?
Pelvic diaphragm = has appearance of sling
What two muscle groups make up the pelvic diaphragm?
Levator ani and coccygeus
What is the urogenital hiatus?
Anterior gap in the pelvic diaphragm between the medial borders = allows passage of urethra and vagina
What forms most of the pelvic diaphragm?
Levator ani
What are the attachments of the pelvic diaphragm?
Pubic bones, ischial spines, tendinous arch of levator ani, perineal body, coccyx, walls of midline organs
What are the three parts of levator ani?
From midline out = puborectalis, pubococcygeus, iliococcygeus
Why must levator ani relax to allow urination and defaecation?
It is tonically contracted most of the time
What is the innervation of levator ani?
Pudendal nerve and nerve to levator ani
What structures offer extra support to the pelvic floor?
Endopelvic fascia and pelvic ligaments
What are some features of the endopelvic fascia?
Connective tissue packing = some loos areolar tissue, some collagen and elastic fibres
What are the pelvic ligaments?
Uterosacral ligament, transverse sacral ligament, lateral ligament of the bladder, lateral rectal ligaments
What are some features of the pelvic ligaments?
Fibrous endopelvic fascia
Provide support to pelvic organs
Where is the deep perineal pouch located?
Lies above the perineal membrane
Lies below the fascia covering inferior aspect of pelvic diaphragm
What are the contents of the deep perineal pouch?
Parts of urethra (and vagina), bulbourethral glands in males, neurovascular bindle for penis/clitoris, extensions of ischioanal fat pads and muscles
Where is the perineal membrane located?
Superficial to the deep perineal pouch = thin sheet of tough deep fascia
Where does the perineal membrane attach?
Laterally to the sides of the pubic arch = closes urogenital triangle, has openings for urethra and vagina
What are the last passive supports of the pelvic organs?
Perineal body and perineal membrane
Where is the superficial perineal pouch located?
Below the perineal membrane
What does the superficial perineal pouch contain in males?
Root of penis = bulb (corpus spongiosum and crura of corpus cavernosum), bulbospongiosus and ischiocavernosus muscles
Proximal spongy urethra, superficial transverse perineal muscle, branches of internal pudendal vessels and pudendal nerve
What does the superficial perineal pouch contain in females?
Clitoris and crura of corpus cavernosum, bulbospongiosus and ischiocavernosus muscles, paired bulbs of vestibule, greater vestibular glands, superficial transverse perineal muscle, branches of internal pudendal vessels and pudendal nerve
What is the normal state of the pelvic floor?
Normally tonically contracted = actively contracts when coughing, sneezing or vomiting
How does the pelvic floor help maintain urinary continence?
External urethral sphincter, compressor urethrae and levator ani all contribute
How does the pelvic floor help maintain faecal continence?
Tonic contraction of puborectalis bends the anorectum anteriorly
Active contraction maintains continence after rectal filling
What are some causes of injury to the pelvic floor?
Pregnancy and childbirth, chronic constipation, obesity, heavy lifting, chronic cough, previous injury, menopause
What is urinary incontinence?
Involuntary loss of urine
What does urinary continence depend on?
Urinary bladder neck support, external urethral sphincter and smooth muscle in urethral wall
What structures can prolapse involve?
Uterus, vagina or both = also bladder and rectum
What causes prolapse?
Failure of support for pelvic organs
What is vaginal prolapse?
Herniation of urethra, bladder, rectum or rectouterine pouch through supporting fascia
How does vaginal prolapse present?
Lump in vaginal wall
What are the different types of vaginal prolapse?
Urethrocele = urethral prolapse Cystocele = prolapse of bladder Rectocele = rectal prolapse Enterocele = prolapse of small bowel
What is uterine prolapse?
Descent of uterus = graded from 1st-3rd degree
What are some symptoms of uterine prolapse?
Dragging sensation
Feeling of lump
Urinary incontinence
What are the treatment options for prolapse?
Sacrospinous fixation and incontinence surgery
What occurs in sacrospinous fixation?
Sutures placed in sacrospinous ligament just medial to ischial spine = performed vaginally, repairs cervical/vault descent
What structures are at risk of injury during sacrospinous fixation?
Pudendal neurovascular bundle and the sciatic nerve
What are the features of incontinence surgery?
Trans-obturator approach = mesh through obturator canal to create sling around urethra, incisions through vagina and groin
