Urinary Incontinence

Urinary Incontinence Khalid A. Yarouf 4MedStudents.com

Outline • Anatomy of lower urinary tract. • Factors influencing bladder behavior. • Continence control. • Classification of incontinence & related issues for each type. • Case.

Anatomy of lower urinary tract • Bladder detrusor muscle: • smooth muscle that appears as a meshwork of fibers. • has 3 distinct layers: outer longitudinal, middle circular & inner longitudinal. • Urethra in adult female: • Muscular tube; 3-4 cm in length. • Surrounded mainly by smooth muscle. • Striated urethral sphincter: • surrounds middle third of urethra. • contributes about 50% of total urethral resistance & serves as 2º defense against incontinence.

Con’t Anatomy • Innervation: • Parasympathetic fibers: • Originate in sacral spinal cord segments S2 thru S4. • Stimulation / administration of cholinergic drugs:  detrusor muscle contraction. • Anti-cholinergic drugs  ↓ vesicle pressure & ↑ bladder capacity.

Con’t Anatomy • Sympathetic fibers: • Originate from thoraco-lumbar segments (T10 thru L2) of spinal cord. • Have α & β-adrenergic components: • α-adrenergic stimulation:  contracts bladder neck & urethra + relaxes detrusor. • β-adrenergic stimulation:  relaxes urethra & detrusor muscle.

Factors influencing bladder behavior • Sensory innervation: • Afferent impulses from bladder, trigone, proximal urethra  pelvic hypogastric nerve  S2 thru S4 levels of spinal cord. • Sensitivity of these nerve endings may be enhanced by: • Acute infection. • Interstitial cystitis. • Radiation cystitis. • Intra-vesical pressure in: • Standing / bending forward position. • a/w obesity, pregnancy, pelvic tumors.

Con’t • Inhibitory impulses relayed by pudendal nerve  also pass thru S2 thru S4 following mechanical stimulation of perineum & anal canal. • Their passage may explain why pain in this region can cause urinary retention. • CNS: Mental, environmental & sociologic disturbances may profoundly alter micturition patterns.

Continence control • Normal bladder holds urine because intra-urethral pressure exceeds intra-vesical pressure. • Pubo-urethral ligaments & surrounding fascia support urethra so that abrupt ↑ in intra-abdominal pressure is transmitted equally to bladder & proximal third of urethra  maintaining a pressure gradient b/w the two. In addition, a reflex contraction of levator ani compresses mid-urethra. • 50% of young, healthy women occasionally experience some degree of urinary incontinence.

Definition of urinary incontinence • = Involuntary loss of urine that is objectively demonstrable & is a social / hygienic problem. • Affects 10-25% of women < 65, 15-30% of non-institutionalized women > 65 years, >50% of nursing home residents. • Pts often rely on absorbent pads / changes in their life style to cope with the condition. They become socially isolated as a result of restricting their interactions with friends & family members.

Classification of incontinence • Stress: • Involuntary loss of drops of urine thru intact urethra, with sudden ↑ in intra-abdominal pressure & in absence of bladder contraction. • Causes: • Weakness of pelvic floor musculature (due to child bearing, previous abdominal/pelvic surgery). • Damage / weakness of urethra or sphincter (e.g. hypo-estrogen of menopause, child bearing).

Con’t Classification (Stress) • Mechanism: • Proximal urethra drops below pelvic floor because of pelvic relaxation defects  ↑ intra-abdominal pressure is not transmitted equally to bladder & proximal urethra i.e. bladder pressure > abdo pressure. • Degrees: • Grade I  incontinence with severe stress (sneezing, coughing, jogging). • Grade II  incontinence with moderate stress (rapid movement, waking up & down stairs). • Grade III  incontinence with mild stress (standing up).

Con’t Classification (Stress) • Dx: • Hx: age, PMHx (previous abdo/pelvic surgery), obstetric (# of deliveries). • Pelvic exam: • Inspection of vaginal walls with Sims speculum  allows visualization of anterior vaginal wall & urethro-vesical junction. • Scarring, tenderness, rigidity of urethra from previous vaginal surgeries / pelvic trauma may be reflected by scarred anterior vaginal wall. • Because distal urethra is estrogen-dependent, pt with atrophic vaginitis also has atrophic urethritis.

Con’t Classification (Stress) • Ix: • Stress test objective test: • Pt is examined with full bladder in lithotomy position. While physician observes urethral meatus, pt is asked to cough. (كانسي) • Stress type is suggested if short spurts of urine escape simultaneously with each cough. If this is demonstrated, then elevate bladder neck with one finger on either side of urethra (Bonney test) or with partially opened Allis clamp (Marshall-Marachetti test) to prevent leakage of urine on coughing. • Delayed leakage / loss of large volumes of urine  suggests uninhibited bladder contractions. • If not demonstrated  repeat with pt in standing position.

Con’t Classification (Stress) • US  to check: • Inclination of urethra. • Flatness of bladder base. • Mobility & funneling of urethra-vesical junction, both @ rest & with Valsalva maneuver. • Bladder / urethral diverticula.

Con’t Classification (Stress) • Urethro-cystoscopy performed pre-operatively to observe: • Amount of residual urine. • Bladder capacity (normal = 400-500 mL of water). • Appearance of urethral & bladder urothelium, noting any inflammation, diverticula, or trabeculation.

Con’t Classification (Stress) • Urodynamic studies: • Cystometrogram: differentiates b/w stress & uninhibited detrusor contraction: • Distend bladder with known volumes of H2O / CO2 observe pressure changes in bladder during filling. • Pt is asked about sensation of bladder fullness  indicates status of sensory innervation of bladder. • Check for presence / absence of detrusor reflex a/w strong desire to void. • Critical volume (400-500 mL) is capacity that bladder musculature tolerates before pt experiences a strong desire to urinate. At this point, if pt is asked to void, a terminal contraction may appear & is seen as a sudden rise in intra-vesical pressure. At the peak of contraction, pt is asked to inhibit this reflex. Pts who can’t inhibit it are referred to as (uninhibited detrusor contraction = detrusor dyssynergia = detrusor hyper-reflexia = irritable / hypertonic / unstable bladder = uninhibited neurogenic bladder).

Con’t Classification (Stress) • Uroflowmetry: • Records rates of urine flow thru urethra when pt is asked to void spontaneously while sitting on uroflow chair. • Normal female voids by the “rule of 20s” i.e. bladder is emptied in < 20 sec @ a rate of 20 mL/sec. For a flow rate to be significant, @ least 200 mL of urine should be voided. • Indication  if signs outflow obstruction are present (pt has difficulty / hesitancy in voiding, incomplete bladder emptying, poor stream, urinary retention).

Con’t Classification (Stress) • Voiding cysto-urethro-gram (VCUG): In this radiologic Ix, fluoroscopy is used to observe: • Bladder filling to know bladder size & competency of its neck during coughing. • Mobility of urethra & bladder base. • Bladder trabeculation, vesico-ureteral reflux during voiding, outflow obstruction.

Con’t Classification (Stress) • Mx: • Non-medical: • Pads. • Kegal exercises (pelvic diaphragm exercises): • Improves / cures mild stress incontinence. • Require diligence & willingness to practice @ home & @ work. • Drugs: • Estrogens: • ↑ sensory threshold for involuntary detrusor contractions. • For atrophic urethritis  improve urethral closing pressure, mucosal thickness & possibly reflex urethral functions. • α-adrenergic stimulants (Pseudoephedrine, Phenylephrine)  enhances urethral closure & improves continence.

Con’t Classification (Stress) • Surgical: • Most commonly employed. • Aim: to correct pelvic relaxation defect & to stabilize & restore the normal intra-abdominal position of proximal urethra. • Approach may be vaginal, abdominal, or combined abdomino-vaginal.

Con’t Classification (Total) • Total: • = Constant / periodic loss of urine without warning. • Causes: vesico-vaginal fistulas (95%), or, uretro-vaginal fistulas. • from previous pelvic surgery (abdo / vaginal hysterectomy) &/ radiation. • Dx: • Hx: painless & continuous vaginal leakage of urine soon after surgery.

Con’t Classification (Total) • Ix: • Instillation of methylene blue dye into bladder will discolor vaginal pack. • IV indigo-carmine dye with leakage of dye into vaginal pack in presence of vesico-vaginal / uretero-vaginal fistula. • Cysto-urethro-scopy: determines site & # of fistulas. • IVP &/ retrograde pyelogram: localizes uterovaginal fistula. • Mx: most of obstetric fistulas can be repaired immediately on detection. For post-surgical fistulas, it’s usual to wait 3-6 months to allow inflammation to settle & tissues to attain good vascularity and pliability.

Con’t Classification (Urge) • Urge: • Urine loss due to uninhibited bladder contractions (detrusor instability). • Causes: • Unknown in most cases. • Local bladder irritation (e.g. cystitis, stone, tumor). • CNS disorder. • CFx: urinary urgency, frequency, urge incontinence, nocturia. • Dx: • Hx: signs of cystitis (frequency, urgency), PMHx (CNS disorder). • Systematic CNS exam. • Urine C & S  exclude infection. • Urodynamics (cystourethrogram): demonstrates uninhibited contractions if unstable bladder, or, small bladder capacity if irritable bladder.

Con’t Classification (Urge) • Mx: • Drugs: it’s reasonable to try several drugs, ↑dose up to max. tolerated, until the most effective drug for a particular pt is found: • Anti-cholinergics: most frequently employed agents  (Oxybutinin / Pro-pantheline). • β-Sympathomimetics (Meta-protere-nol). • Estrogens: • ↑ sensory threshold for involuntary detrusor contractions. • For atrophic urethritis  improve urethral closing pressure, mucosal thickness & possibly reflex urethral functions. • Smooth muscle depressant (Flavoxate). • Diazepam (Valium): •  smooth muscle relaxant + anti-cholinergic effect + CNS sedation. • TCAs (Imipramine): have anti-cholinergic action + enhances continence by its α-adrenergic stimulation of urethra.

Con’t Classification (Urge) • Bladder training: Represents behavior modification designed to repeat process of toilet training. Aim is to ↑ bladder capacity day by day & to prolong intervals b/w voiding.

Con’t Classification (Overflow) • Overflow: • Urine loss when intra-vesical pressure exceeds urethral pressure. • Causes: • Hypotonic bladder = Detrusor-sphincter dyssynergia  due to: • DM, autonomic neuropathy, LMN disease, spinal cord injuries. • Outflow obstruction (e.g. stricture). Ask about: straining to void, poor stream, urinary retention, incomplete emptying. • Best Mx: Self-catheterization.

Con’t Classification (Functional) • Functional: • Urine loss caused by inability to reach toilet in time. • Cause: physical immobility.

Case • Mrs. Badria a 45-year old Lebanese Accountant, Para 5 +1, requested a gynecological consultation because she was extremely worried about involuntary loss of urine during coughing, sneezing & laughing. Her symptoms followed an attack of chest infection 6 months previously and are progressively getting worse. She is embarrassed to have sexual intercourse with her husband because of smell. This problem is also limiting her social activities such as shopping, visiting friends and walking. She was reluctant to seek medical care initially but is now concerned about the possibility of having a neurological problem causing involuntary urination.

Con’t Case • All her deliveries were normal. Her LMP occurred 2 weeks previously. She has recently gained 10 Kg of body weight and smokes 20 cigarettes/ day. There were no other urinary symptoms. During vaginal examination in the lithotomy position, urine was seen spurting from urethra on straining but there were no other obvious abnormalities. In the left lateral position, no protrusion of vagina was demonstrated on straining.

Urinary Incontinence