Eval/treatment of female urinary incontinence

Question 1

Define Urinary Incontinence

Answer 1

Involuntary loss of urine that is objectively demonstrable and is a social or hygenic problem. It has been reported to affect 15-50% women- prevalence increases with age, reaching >50% in elderly in nursing homes

Question 2

Normal bladder function/phase

Answer 2

• Filling/storage phase + Emptying phase

Filling/Storage
- highly elastic detrusor smooth muscle bundles stretch to keep pressure low as bladder fills. Urethral sphincter under high pressure to maintain constant intra-vesical pressure

• 100 cc volume = first sensation of bladder fullness
• 250 mL - first desire to void (bladder at 1/2 filling capacity)
• 500 cc - max cystometric bladder capacity achieved– strong desire to void and beginning of emptying phase.
• Chose to void: urethral sphincter voluntarily relaxed, pelvic floor relaxes, detrusor contracts —> Micturition
• nl post void residual

Question 3

Normal Innervation

Answer 3

Lower UT under parasympathetic and sympathetic innervation
- Parasympathetic (Pelvic nerve) from S2-4. Stimulation = detrusor contracts. Anticholinergic drugs reduce bladder pressure/increase capacity

• Sympathetic: fibers from T10-L2 of spinal cord with alpha and beta components. (hypogastric)
• Beta fibers: mainly in detrusor: stimulation relaxes urethra and detrusor.
• alpha mostly in urethra
• beta adrenergic stimulation – relaxes urethra and detrusor
• Pudendal nerve (S2-4) provides motor innervation to striated urethral sphincter

Question 4

Vaginal axis

Answer 4

Vagina is midline with freedom in distensibility from both bladder and rectum. Attached to sidewall via connective tissue

• connective tissue in lateral to lower 1/3 of vagina attached to fibers of pubococcygeal muscle adn to fibers fixing it to perineal membrane

Question 5

Urethra and sphincter

Answer 5

Urethra = muscle tube with transitional epithelium; continuous with bladder epithelium internally and vaginal epithelium externally. Smooth muscle mostly longitudinal and oblique – under alpha-adrenergic control (intrinsic sphincter)

External sphincter (rhabdosphincter)= striated muscle surrounding distal 2/3 of urethra; contributes ~50% of total resistance & secondary defense against incontinence. Responsible for urinary flow at end of micturition

Question 6

3 things holding up pelvic structures (bladder, vagina, urethra)

Answer 6

• Levator Ani
• Arcus tendinous fasciae pelvis
• Endopelvic fascia (pillow on top of hammock)

Question 7

Steps of Storage phase of urination

Answer 7

Beta receptors on detrusor sense stretch – send message to sacral spinal cord to activate pudendal nerve – constricts external sphincter (alpha)

Hypogastric nerve allows detrusor to relax/expand (beta receptors)

Need higher pressure in urethra than bladder to maintain continent

Neurotransmitters:

• NE and serotonin released
• signals detrusor to relax and urethra to contract

Question 8

Emptying Phase

Answer 8

controlled by Pontine micturition center
- input from bladder to Pontine center sending message to cerebral cortex to devide if good place to urinate

• Message via hypogastric to detrusor to relax and pudendal nerve relaxes external urethral sphincter –> urination

Neurotransmitters
- ACh released to detrusor to contract

Question 9

Genuine Stress incontinence

Answer 9

involuntary loss of urine when bladder pressure > urethral pressure

• usually with cough/sneeze
• accounts for almost half of all cases of urinary incontinence
• most commonly accepted theory = urethral hypermobility due to vaginal wall relaxation, displacing bladder neck and proximal urethra downward. When this happens, increased intra-abd pressure from cough/seeze/etc no longer transmitted equally to bladder and proximal urethra. Normal urethral resistance overcome– leakage
• 2nd possible mechanism = intrinsic sphincter deficiency - urethra fails to close in response to increases in intra-abd pressure

SYMPTOMS

• leak occurs in spurt
• usually with predictable activity (laugh, cough, sneeze, jumping jacks)
• Rarely when supine, usually while upright
• leak occurs while intra-abdominal pressure increased

Risk factors
- childbirth, prior UG surgery, pelvic radiation, estrogen deficiency (nenopause) and medications such as diuretics/alpha blockers

Question 10

Detrusor instability/overactive bladder/urge incontinence

Answer 10

• all characterized by overactive detrusor, usually with strong urge to void and inability to defer voiding

SXS

• urgency
• nocturia
• frequency (nl person:

Question 11

Mixed incontinence

Answer 11

combo of stress incontinence and detrusor instability

Question 12

What to ask when working up pt for urinary incontinence

Answer 12

• Type of leakage
• Triggers
• Onset of symptoms
• Severity
• Pad usage
• Impact on quality of life
• Past medical history
• Past surgical history
• Medication

Question 13

What receptors are on the bladder

Answer 13

M2 and M4 receptor found in bladder and cause detrusor contraction when stimulated

M3 specifically directly evoke bladder smooth muscle contraction, and M2 receptors indirectly reverse sympathetic mediated smooth muscle relaxation

Question 14

Pharmacology for incontinence

Answer 14

• Antimuscarinic agents usefyl but can antagonize muscarinic receptors on other body parts– side effects (dry mouth, constipation, blurred vision, drowsiness)
• Antispasmodics (oxybutynin, Tolterodine, Fesoterodine)
• Antimuscarinics (trospium, Solifenacin, Darifenacin)

Question 15

What supports the urethra/holds it in place

Answer 15

– these 2 posterior pubo-urethral ligaments provide suspensory mechanism for urethra and serve to hold it forward close to pubis during stressful conditions

• urethra held in place by 2 systems. Suspended by perineal membrane and its attachment to the pubic bone for most of its length by arched, bilaterally symmetric, anterior, posterior, and intermediate pubo-urethral ligaments

Question 16

What is the urogenital diaphragm

Answer 16

AKA perineal membrane
- triangular structure of fibromuscular tissue covering anterior pelvic outlet. Runs between inner surfaces of ischio-pubic ramiand is pierced in middle by urethra/vagina. It assists in holding these structures in place. Posterior fibers of perineal membrane fixed to perineal body

Question 17

Levator Ani

Answer 17

bilaterally paired, posteriorally fused muscles that maintains vagina, bladder, uterus, rectum within pelvis

• urethra, vagina, rectum pass through levator hiatus as they exit pelvis (separation between levator ani)

Question 18

Pelvic Organ Prolapse

Answer 18

• Protrusion of pelvic organs into vaginal canal or beyond vaginal opening due to weakness in fascia investing the vagina, along with its ligamentous supports
• Increased intra-abdominal pressure or attenuated fascia/ligaments/muscles can cause this

Question 19

Anterior vaginal prolapse

Answer 19

(Cystocele)

• anterior vagina = most common site
• vaginal fullness, heaviness, pressure, and discomfort often progresses over day and most noticable after prolonged standing/straining
• may have to apply manual pressure to empty bladder completely
• other sxs = stress urinary incontinence
• if significant prolapse beyond vaginal opening can cause urethral obstruction from kinking -> retention

Question 20

Posterior vaginal prolapse

Answer 20

(Rectocele and Enterocele)

• occurs due to weakness in rectovaginal septum
• sxs similar to other types of prolapse
• when difficulty with bowel function/defectaion, lower posterior vaginal prolapse likely
• may need to strain or manually splint

Rectocele = Bulge of lower end of rectum causes pushing on posterior vagina/uterus

Enterocele - upper posterior vaginal prolapse where rectouterine pouch extends/bulges lower to sit between vagina/rectum

Question 21

How do we quantify pelvic organ prolapse

Answer 21

Pelvic Organ Prolapse Quantification system (POP-Q)
- extent of prolapse measured relative to hymen (fixed landmark)

Genital hiatus - space between urethra and vagina

• perineal body- tissue between vagina and rectum

Question 22

Exam

Answer 22

Physical exam- vaginal exam with speculum. Can depress anterior or posterior wall and have pt strain– will accentuate defects of opposite wall

• Stress test: examine pt with full bladder and have pt cough while you observe urethral meatus. SUI if short spurts excape simultaneously with each cough
• Q Tip Test: determines mobility/descent of urethrovesical junction on straining. Can differentiate from anterior vaginal laxicity alone. Look at angle between horizontal and cotton swab. In pts with pelvic relaxation/SUI, change in cotton swab angle ranges from 30-60 degrees or more. Replaced by visual inspection of urethral mobility during valsalva

Simple Cytometry

• differentiate between uninhibited detrusor contraction and those with SUI
• place catheter in bladder and gradually distend from below in retrograde
• collects info about bladder volume, pressure
• pt indicates when she experiences physiologic cues of nl micturition cycle and feedback is correlated with volumes and pressure recorded from bladder
• pt will report need to void at lower than nl bladder volume

Multi-Channel Cystometry
- more extensive ascertains if multiple etiologies contributing

Question 23

what two things determine vesicular pressure

Answer 23

Detrusor muscle pressure and background pressure of abdominal cavity

Bladder pressure and background pressure measurable to calculate detrusor pressure

P(ves0 = P (det) + P (abd)

Question 24

Overflow incontinence

Answer 24

also urinary retention

• detrusor areflexia or hypotonic bladder, as is seen wiht lower motor neuron dz, spinal cord injury, autonomic neuropathy (diabetes)
• also can occur when obstruction

Classic SXS
- straining to void, poor stream, retention of urine, and incomplete emptying may indicate obstructive disorder

Question 25

GU Fistulas

Answer 25

uncommon cause of urinary incontinence in US
- pelvic surgery/radiation account for 95% vesico-vaginal fistulas, usually due to devascularization rather than direct injury

Obstetric fistula = remendous source of physical distress in developing countries; attributed to complicated labor on the order of days and pressure necrosis from fetal head on maternal tissue
- incomplete eval/repair of lacerations at time of delivery also contribute

CLASSIC SXS
-classic hx of continuous vaginal leakage of urine after delivery, pelvic surgery, or pelvic irradiation strongly suggestive of fistula between urinary/repro tracts

Question 26

Vesico-vaginal fistula

Answer 26

Fistula between bladder and vagina
- tissue flap may be interposed between bladder and vagina to provide support, vascularity and strength to suture line

• large radiation-induced fistulas may require urinary condiut for urinary diversion

Question 27

Ureterovaginal fistula

Answer 27

between ureter/vagina
- also fistula between urethra and vagina = ureterovaginal
treatment is location/size dependent
- Small- usually close spontaneously after stent placement to relieve pressure on fistula tract
-

Question 28

How to diagnose fistulas

Answer 28

Methylene blue dye can be instilled directly into bladder. If fistula–dye leaks and discolors gauze in vagina

• IV indigo carmine dye also excreted by kidneys into urine and will discolor vaginal pack if fistula between vagina and bladder or between vagina and ureter

Question 29

Management of urinary incontinence

Answer 29

• Prophylaxis- ID/treat chronic disorders, correct constipation and intra-abd disorders that can cause increases in pressure; estrogen to menopausal women
• Behavioral modification(avoid fluids, Kegels) for better control

Kegels= proven first line therapy to improve or cure mild to moderate SUI, esp if only mid degree of pelvic relaxation. They work to increase urethral tone and therefore resistance to leakage
- Pts taught to ID/contract levator ani; regular repetitions throughout day and when episode of incontinence likely (i.e. prior to sneeze)

Pessaries- provide intravaginal support. can be used to correct prolapse/restore continence by “propping up” vagina

Estrogen
- absence of estrogen causes urethral tissue to atrophy. Estrogen can improve urethral closing pressure and urethral epithelial thickness/vascularity and reflex urethral function

Anticholinergics/antimuscarinics (stimulate M2/3 to contract detrusor)-

• oxybutynin chloride = smooth muscle relaxant
• Tolterodine - muscarinic antagonist
• Imipramine hydrochloride - tricyclic antidepressant acting via anticholinergic properties to increase bladder storage. Improves bladder compliance opposed to counteracting contraction and blocks post-synaptic noradrenaline uptake to increase outlet resistance

Treat intrinsic sphincter deficiency via bulking injections (bovine collagen)

Surgery

Question 30

Most commonly employed treatment for SUI

Answer 30

Surgery
- aim is to correct pelvic relaxation defects and stabilize/restore nl supports of urethra

Retropubic urethropexy: places sutures in fascia lateral to /on each side of bladder neck adn proximal urethra and elevating vesico-urethral junctionby attaching the to symphysis pubis or to Cooper’s ligament.

Sling procedures: seing pts fascial tissue or mesh under bladder neck or urethra