structure and function of prostate gland and potential treatments for BPH Flashcards
prostate disease can be _____ or _______
benign or malignant
benign prostatic enlargement vs hypertrophy vs hyperplasia vs obstruction
enlargement = clinical
hypertrophy (increase in size or volume of cell) and hyperplasia (number of cells) = histologic
obstruction = urodynamic (symptomatic)
avoid the term ‘prostatism’
what is dysuria?
pain passing urine
what does the upper urinary tract consist of?
kidney and ureter
what does the lower urinary tract consist of?
bladder, prostate and urethra
what lower urinary tract storage symptoms are there?
failure to store
- frequency
- nocturia
- urgency
- urge incontinence
what lower urinary tract voiding symptoms are there?
- hesitancy
- poor stream
- straining
- intermittency
- feeling of incomplete voiding
what are post micturition symptoms?
a feeling of incomplete emptying (used to be under voiding symptoms)
what is frequency?
voiding less than every 2 hours
what is nocturia?
voiding 2 or more times during the night
what is urge incontinence?
when you leak before reaching the toilet
what are red flag symptoms?
- pain = dysuria
- blood = haematuria
- leak at night = enuresis
- recurrent infection
- symptoms of renal failure
what are 2 causes of dysuria?
bladder infection or stone
what are things to assess in examination?
- general = gait, tremor, pedal edema
- abdomen = palpable bladder
- genitalia = phimosis, meatal stenosis, swelling/tenderness of testis or epididymis
- rectal exam rubbery, smooth, midline groove
- neurological bulbocavernosal reflex, lower limb reflexes
what could pedal oedema be a sign of?
renal failure — check creatinine
palpable bladder : acute vs chronic retention
acute = palpable and painful
chronic = palpable and painless
what is phimosis?
inability to retract foreskin
what is meatal stenosis?
narrowing of the opening of the urethra
what can swelling/tenderness of testis or epididymis be a sign of?
epididymis orchitis — can occur if patients have problems emptying their bladder properly and so develop infection
why should you test anal sphincter function?
sacral plexus (S2-S4) supplies both the anal sphincter and the bladder — therefore if the anal sphincter tone is slow, the bladder function is also affected
aim of DRE?
estimate size of prostate — normally can reach top and not more than 2 fingers wide
how is a bulbocavernosus reflex carried out?
squeeze the glands penis in men and touch the clitoris or labium minus in women to stimulate the reflex, while checking for a reflex contraction of the external anal sphincter
what differential diagnoses are there?
- prostate — benign enlargement/cancer
- bladder — overactive/underactive
- urethra — stricture
- infection — cystitis/prostatitis
- psychological — anxiety
what are the zones of the prostate gland?
central, peripheral, fibromuscular and transitional
describe the peripheral zone
- largest zone — contains 70% of the gland
- outer portion in posterior most portion of gland
describe the central zone
- the portion of the prostate located between the 2 ejaculatory ducts
- accounts for 20% of the gland
describe the fibromuscular stroma
- contains no gland
- anterior in gland
what zone directly surrounds the urethra?
transitional zone
what happens when the transitional zone becomes enlarged?
causes obstruction of the urethra
most malignancies of the prostate occur in which zone?
peripheral
relations of the prostate gland
superior = bladder
inferior = sphincter
lateral = levator ani muscle
anterior = pubic symphysis
posterior = rectum
describe the structure of the prostate
- inverted pyramid
- 15-20 gms
- 2 by 3 by 4 cm
- consists of smooth muscle, stromal and glandular
- ratio changes with disease
most of the problem with BPH occurs in what area?
transitional zone
what are the functions of the prostate?
fertility
- PSA enzyme - semen liquefaction
- antegrade ejaculation — muscularis ejaculatorius
- contributes to 25% ejaculate volume — acidic
- milieu for sperm to thrive Nutrition Antimicrobial (Zn, selenium)
what is seminogeline?
- in semen
- causes coagulation in semen
- coagulant lysed in the female genital tract by the PSA
- PSA activated by acidic milieu of female genital tract
what % of semen comes from the seminal vesicle? acidic or alkaline?
70% - alkaline
is the contribution of the prostate to semen alkaline or acidic?
acidic
what happens to the semen in ejaculatory duct obstruction?
becomes acidic — part coming from seminal vesicle is absent
pathogenesis of the enlargement
- increase in number of cell vs reduced apoptosis - balance
- androgen/oestrogen ratio — receptor signalling affected
- imbalance of growth factors — EGF, KGF, IGF vs TGF (transforming - only one that reduces the growth of the prostate, all the others increase the growth)
static component — sheer size of gland
dynamic component — smooth muscle action
investigations
- urinalysis and msu for culture — infection or haematuria
- urea electrolytes and creatinine
- PSA
- flow rate and post void scan
optional
- imaging — US
- flexible cystoscopy
you can be 90% certain it is a UTI if both what are present?
leucocytes and nitrites
management
- check for abnormal findings
- history : red flags
- examination : palpable bladder/phimosis/abnormal feeling prostate
- bloods : renal impairment/raised PSA
- urine — UTI/haematuria
- assess symptom severity : IPSS
what is IPSS?
International Prostate Symptom Score = 7 questions, assesses severity of symptoms
IPSS score is out of what?
35
when should you reassure the patient (no specific treatment)?
- mild symptoms
- normal investigations — eGFR/post void residual, PSA/MSU
- patient’s preference
what treatments are available?
- medical — alpha blockers, 5 alpha reductase inhibitors, anticholinergics, combinations
- catheters
- minimally invasive
- surgery
what receptors does the smooth muslce component of the prostate have?
alpha 1a adrenergic receptors
what happens if you block the alpha receptors in the prostate?
smooth muscle relaxes - channel opens - helps with obstruction
examples of alpha receptor blockers
tamsulosin, alfuzosin, terazocin, doxazocin
advantages and disadvantages of alpha receptor blockers
advantages:
- quick onset
- does not affect PSA
- symptomatic relief
disadvantages:
- headaches
- postural hypotension
- retrograde ejaculation
- has no effect on prostate growth
what are 2 examples of 5 alpha reductase inhibitors?
finasteride, dutasteride
what do 5 alpha reductase inhibitors do?
prevents conversion of testosterone to dihydrotestosteone — shrinks the prostate with time
what components do they address? a receptor blockers vs 5 alpha reductase inhibitors
a receptor blockers = dynamic component
5 alpha reduces inhibitors = static component
advantages vs disadvantages of 5 alpha reductase inhibitors
advantages:
- symptomatic relief
- shrink prostate
- reduce risk of retention
- promote hair growth in male pattern baldness
disadvantages:
- slow onset
- reduced libido/weak erection
- gynaecomastia
- affect PSA
testosterone vs dihydrotestosterone potency
dihydrotestosterone is many times more potent than testosterone
what are anticholinergics used for?
to control associated storage symptoms
what do phosphodiesterase 5 inhibitors cause?
nitric oxide mediated smooth muslce relaxation
what phototherapy agents can be sued?
saw palmetto (serenata repens), pygeum africanum
what is prostate embolisation?
block blood supply of the prostate
what are minimally invasive treatments?
- water vapour
- embolisation
- stent to pull lobes apart
what proper surgical options are there?
- transurethral resection of prostate TURP - remove a bit at a time
- holmium enucleation of prostate HoLEP - remove all at once
