Urinary Incontinence and Benign Prostatic Hyperplasia Flashcards
What is BPH?
Benign Prostatic Hyperplasia
How and when does the prostate develop in utero / gestation?
Develops between weeks 10-16 of gestation from epithelial buds which branch out from the posterior aspect of the urogenital sinus to invade the mesenchyme
Influenced by the hormone dihydrotestosterone, which is produced by epithelial cells
Stromal-epithelial interaction is important, dihydrotestosterone acts on mesenchymal androgen receptors
What is the venous drainage of the prostate?
The venous drainage is via the peri-prostatic venous plexus
This also receives the deep dorsal vein of the penis and numerous vesical veins
The periprostatic venous plexus drains into vesical plexus and internal iliac vein
What is the lymphatic drainage of the prostate?
internal iliac lymph nodes and sacral nodes
What is the role of the capsule?
The capsule transmits the ‘pressure’ of tissue expansion to the urethra and leads to an increase in urethral resistance
How is active smooth muscle tone regulated?
Active smooth muscle tone is regulated by the adrenergic nervous system
(alpha-1A) ⍺1A is the most abundant adrenoceptor subtype in the human prostate
What is the function of the prostate?
secrete 75% of seminal fluid which liquifies coagulated semen after deposition in the female genital tract.
What is Lower Urinary Tract Symptoms (LUTS)?
Non-specific term for symptoms which may be attributable to lower urinary tract dysfunction
What is meant by Benign Prostatic Enlargement (BPE)?
Clinical finding of enlarged prostate
i.e. during rectal examination - feel of an enlarged prostate
What is meant by Benign Prostatic Hyperplasia (BPH)?
Histological diagnosis - increase in number of cells
What is meant by Benign Prostatic Obstruction (BPO)?
Bladder outflow obstruction caused be BPE
What is meant by Benign Prostatic Hypertrophy?
Pathologically incorrect - increase in cell size
What is the pathophysiology of BPH?
Increased number of epithelial and stromal cells in both lateral lobes and median lobes in response to testosterone and growth factors.
Results in increased urethral resistance (as enlarged prostate puts pressure against the walls of the urethra) resulting in compensatory changes in bladder function
How does bladder function change in BPH to lead to reduced urinary flow, increased urinary frequency, urgency and nocturia?
Detrusor = smooth muscle wall of the bladder
The detrusor muscle remains relaxed to allow the bladder to store urine, and contracts during urination to release urine
The detrusor muscle pressure required to maintain urinary flow in the presence of urethral (outflow) resistance happens at the expense of normal bladder storage function
The urethral obstruction induces changes in the detrusor function - this causes the BPH related symptoms
What is LUTs related to in men with BPH?
LUTS caused by obstruction induced changes in bladder function rather than the symptoms being caused directly by the outflow obstruction
This is shown because approx. 1/3 of men continue to have significant voiding (urinating) dysfunction even after surgical relief of obstruction
What is really important to ask about for lower urinary tract symptoms?
Fluid intake
What investogations are performed for suspected BPH?
Investigations:
- Urine dipstick/ MCS
- Post-void residual
- Voiding diary - intake, output, and frequency
- IPSS questionnarie - designed specifically to ask about prostate enlargement
Bloods:
- PSA (prostate specific antigen test)- predict prostate volume
Imaging:
- USS KUB (ultrasound scan kidneys, ureters, bladder) if impaired renal function, loin pain, haemturia, renal mass on examination
- Flexible cystoscopy (if cancer concern)
- TRUS (transrectal ultrasound scan) prostate
Other:
- Urodynamic studies = test for finding out how your bladder, sphincter and urethra are working
What is the management for BPH?
1. Non-bothersome: Behavioral management and watchful waiting: - weight loss - reduce caffeine - avoid constipation
- Bothersome symptoms:
Drugs
- alpha-adrenergic antagonists- Target a1A receptor and lead to muscle relaxation
e.g. Tamsulosin, alfuzosin, doxazosin
- 5-alpha-reductase inhibitors - prevent conversion of testosterone to dihydrotestosterone (promotes growth and enlargement). Leads to shrinkage and improves obstructive symptoms. Given for large prostates >30g
e.g. Finasteride, Dustasteride - Surgery
- TURP = transurethral resection of the prostate - cystoscope placed inside urethra and prostate tissue shaved away. Makes adequate channel for urine flow
What are the different types of urinary incontinence?
Urinary incontinence (UI) = any involuntary loss of urine
Stress (urinary) incontinence (SI) =
the complaint of involuntary leakage on exertion /sneezing/coughing
Urge (urinary) incontinence (sometimes referred to as OAB - overactive bladder) = the complaint of an involuntary leakage accompanied by or immediately preceded by urgency
Mixed urinary incontinence =
More than 1 type. Seen in older patients
Continuous incontinence = continuous leakage (could be suggestive of vesicovaginal fistula, ectopic ureter (from kidney to urethra or vagina))
Overflow incontinence =
leakage when bladder is full, associated with chronic urinary retention secondary to obstruction or atonic bladder
Functional incontinence=
due to severe cognitive impairment or mobility limitations, preventing use of toilet. Bladder function is normal
Nocturnal enuresis =
the complaint of loss of urine occurring during sleep
Post-micturition dribble =
the complain of an involuntary loss of urine immediately after passing urine (usually in men, after full stream of urine, few drops come out at the end)
What are the causes of urinary incontinence?
Increasing age Pregnancy and vaginal delivery - due to effects on pelvic floor and pressures on the bladder Obesity Constipation Drugs e.g. ACEi Smoking Family History Prolapse / hysterectomy / menopause
What is the defintion and epidemiology of stress (urinary) incontinence (SUI / SI)?
SUI / SI = involuntary loss of urine on effort or physical exertion or on coughing or sneezing
Can affect 40% of women, more common in older women (1/5 women have some degree of SI)
What are the conservative / non-surgical interventions for SUI/SI?
Lifestyle changes
- Weight loss
- Cessation of smoking
- Modification of high/low fluid intake
- Decreased physical exertion
Supervised pelvic floor exercises - patients that try to do them alone often don’t do them correctly
What are the medical / pharmacological options for SUI/SI?
Duloxetine- inc. norepinephrine and serotonin (SNRIs) to increase urethral sphincter contraction
Oestrogen
What are the surgical options for SUI/SI?
Periurethral bulking agents - agent around urethra to cause physical obstruction (alternative to surgery)
Artificial urinary sphincter - part of the device goes around the urethra to place pressure on it - button needs to be pressed to get rid of the pressure so they can pass urine
Mid-urethral sling - prevents too much movement of the urethra and supports urethral sphincter
Colposuspension- stitches either side of bladder opening to stop it from moving when exerting
What does the female genitourinary system include?
composed of 2 kidneys, 2 ureters, urinary bladder and urethra.
What is the anatomy of the ureters?
25cm long, upper half lies in abdomen and lower half in pelvis.
3mm in diameter but slightly constricted at 3 places (pelvic ureteric junction, pelvic brim, as it passes through the bladder wall).
Ureters 3 layers of tissue-outer fibrous tissue, middle muscle layer and inner epithelium layer.