8.4 Urethral Strictures, Urine Retention, Enuresis & Incontinence Flashcards
What are the 4 parts of the urethra?
- Penile urethra (longest)
- Bulbar urethra (thickest)
- Membranous urethra (through external sphincter)
- Prostatic urethra (cavity down prostate lined with urethelium)
Pathophysiology of urethral stricture
- small mucosal fold/stricture
- complete fibrosis
- complex stricture involving fistula
Urethral stricture etiology
FIBROSIS DUE TO INSULT TO URETHRA
- infective (urethritis: gonococcal, non-gonococcal)
- inflam (BXO/lichen sclerosis)
- iatrogenic trauma (iatrogenic {catheterisation})
- saddle/straddle injury (bulbar urethral injury)
- pelvic fracture (membranous urethra injury)
- radiation (pelvic radiation {prostate, bladder, penile cancer})
- Malignancy (urethral carcinoma)
Urethral strictures complications
DUE TO STASIS OF URINE
- infective (cystoprostatitis, epididymo-orchitis, pyelonephritis, paraurethral abscess, gangrene)
- baldder wall structural changes (hypertropy, diverticulations)
- Calculi (bladder & urethral stones)
- infertility
- obstructive uropathy
Components of micturition
1. Filling (storage)
- bladder (detrusor): able to stretch to capacity (compliant)
- urethral sphincter (able to contract)
2. Emptying (voiding)
- bladder: able to contract
- urethral sphincter: able to relax
Urine retention causes
Mechanical:
- Prostate: BPH, cancer, prostatitis
- urethra: stricture, trauma
- newborns: valves
Clot retention:
- Bladder, prostate cancer
Neurological
- LMN leison
Drugs
- anticholinergics
- sympathomimetics
- diuretics
- alcohol
Constipation
- children
Psychogenic causes
Anuria vs. Retention
Anuria
- failure of kidneys to produce urine
- no urine to urinate
Retention
- kidneys producing urine
- inability to empty bladder
Define Enuresis
Enuresis = “bedwetting”
Def: involuntary loss of urine beyond age of anticipated control, >2/month in children older than 5 years
- usually resolve with age, but 15-5% not
Enuresis theories
- Inappropriate LOSS of ADH surge in evening
- ⬇️ functional bladder capacity
- deep sleeper
- genetics
- developmental delay
NB classification of enuresis
Primary - child has never been dry at night
Secondary - child has been dry for period of at least 6 months
Monosymp - only nocturnal, no other daytime symp (during day child is dry; only wet at night)
Polysymp - day time symp of urinary frequency, urgency, staccato voiding (maybe neurological problem)
Incontinence causes
1. Failure to store
Bladder:
- involuntary contractions (idiopathic, neurogenic)
- ⬇️ capacity (TB, radiation)
Urethral (sphincter):
- loss of pelvic support
- post surgery / radiation
- sacral neorological lesions
2. Failure to empty
Bladder:
- acontractile bladder
- neurogenic bladder
- drugs
Urethral sphincter:
- anatomical outflow obstruction
- func obstruction in neuropathic bladder, destructor sphincter dyssenergia
Transient incontinence causes
Delirium
Infection
Atropic vaginitis
Pharmaceuticals (diuretics)
Psychological
Excessive urinary output
Restricted mobility
Stool impaction
Different types of incontinence
FOUND BY HISTORY TAKING
Stress urinary incontinence:
- involuntary leakage on effort or exertion (sneeze, cough)
- insufficient urethral closure pressure
- raised intra-abdom pressure
- Etiology - post-prostatectomy incontinence (sphincter damage)
Urgency incontinence:
- involuntary leakage with strong, sudden and uncontrollable desire to urinate
- involuntary detrusor contractions
- urgency, frequency and nocturia
- Etiology - idiopathic / neurogenic detrusor overactivity
Mixed urinary incontinence:
- Stress + urgency
Overflow incontinence:
- continuous dribbling incontinence with high urine residual volumes
- Etiology- decompensated detrusor mechanism, severe outflow obstruction
Paradoxical incontinence:
- involuntary leakage of urine in between normal voiding
- Etiology - ectopic ureter; ureterovaginal fistula
Total incontinence:
- continuous dribbling urination without high urinary residual vol
- failure of sphincter coaptation or fistulous communication involving bladder
- Etiology - vesicouterine fistula; pelvic radiation; iatrogenic sphincteric injury
