Urinary incontinence and BPH Flashcards
LO:
This session aims to discuss:
- Benign Prostatic Hyperplasia
- Causes and types of urine incontinence
- Pathophysiology and clinical management of urge and stress urinary incontinence.
This session mainly relates to the following TILOs:
- BRS-URO-1: Genitourinary structure and function: Describe the structural and cellular organisation of the kidney, bladder, and prostate and relate this to function.
- 1-BRS-URO-3: Genitourinary disorders: Summarise the pathology and pathophysiology of genitourinary disorders.
- 1-BRS-URO-4: Genitourinary disorders: Describe the clinical features and treatment options of genitourinary disorders.
Session plan:
BPH (Benign Prostatic Hyperplasia)-embryology and blood supply:
The prostate 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.
Stromal-epithelial interaction is important through the production of dihydrotestosterone by epithelial cells acting on mesenchymal androgen receptors
The arterial blood supply is from the branches of the inferior vesical artery. This provides the prostatic artery which divides into urethral and capsular groups of arteries. From the urethral group arise Flock’s and badenoch’s arteries (both at 1 and 11 o’clock and Badenoch’s arteries approach it at 5 and 7 o’clock. The capsular branches of th prostatic artery run with the cavernosal nerves.
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 eventually drains into the internal iliac vein.
The lymph drainage is mainly to the obturator nodes and then the internal iliac chain.
BPH (Benign Prostatic Hyperplasia):
Zonal anatomy of prostate and function:
Transitional zone (green)-sits mainly around urethra. This is where BPH is most likely to occur
BPH (Benign Prostatic Hyperplasia): many different terms used for lower urinary tract symptoms
•Lower Urinary Tract Symptoms (Prostatism)
•non-specific term for symptoms which may be attributable to lower urinary tract dysfunction eg someone who has urgency, incontinence, flow issues etc.
•Benign Prostatic Enlargement
•clinical finding of enlarged prostate
•Benign Prostatic Hyperplasia
•histological diagnosis (can’t make without tissue evidence)
•Bladder Outflow Obstruction
•urodynamically proven obstruction to passage of urine
This is an effect of BPH
•Benign Prostatic Obstruction
•= BOO caused by BPE
•Benign Prostatic Hypertrophy
•pathologically incorrect
BPH (Benign Prostatic Hyperplasia): pathophysiology
Pathophysiology of BPH
Increased number (as opposed to size) of epithelial and stromal cells in the peri-urethral area of the prostate in response to androgens (testosterone-hormone most responsible for growth of prostate) and growth factors
The pathophysiology of BPH is complex
BPH increases urethra resistance, resulting in compensatory changes in bladder function. However, the elevated detrusor pressure required to maintain urinary flow in the presence of increased outflow resistance occurs at the expense of normal bladder storage function. Obstruction induced changes in detrusor function, compounded by age-related changes in both bladder and nervous system function, lead to urinary (FUN) frequency, urgency and nocturia, the most bothersome BPH-repated complaints
One of the unique features of the human prostate is the presence of the prostate capsule, which plays an important role in the development of LUTS. In the dog, the only other species known to develop naturally occurring BPH, symptoms of BOO and LUTS rarely develop because the canine prostate lacks a capsule. Presumably the capsule transmits the ‘pressure’ of tissue expansion to the urethra and leads to an increase in urethral resistance.
The size of the prostate does not correlate with the degree of obstruction. Thus other factors such as dynamic urethral resistance, the prostatic capsule, and anatomic pleomorphism are more important in the production of clinical symptoms than the absolute size of the gland.
BPH is a true hyperplastic process ie increase in cell number – the term benign prostatic hypertrophy is pathologically incorrect.
Note: can think of Luts symptoms as storage (FUN) and voiding (HIP)
BPH (Benign Prostatic Hyperplasia) development:
Alpha 1 adrenoreceptor are the most abundant adrenoreceptor subtype in the human prostate.
Compliance is a measure of how stretchy the bladder is.
Detrusor failure-bladder doesn’t pump at all-so can cause urinary retension.
Early peri-urethral nodules are purely stromal in character
The earliest transition zone nodules represent proliferation of glandular tissue
During the first 20 years of BPH development, the disease may be predominantly characterised by an increased number of nodules, and subsequent growth of each nodule is generally slow. Then a second phase of evolution occurs in which there is a significant increase in large nodules. In the first phase, the glandular nodules tend to be larger than the stromal nodules. In the second phase, when the size of the individual nodules is increasing, the size of glandular nodules clearly predominates.
Prostatic smooth muscle represents a significant volume of the gland, although the arrangement is not optiomal for force generation
Urethral resistance is can be increased by active and passive forces.
Active smooth muscle tone in the human prostate is regulated by the adrenergic nervous system. ⍺1A is the most abundant adrenoreceptor sybtype in the human prostate
The bladder’s response to BPH is adaptive. But many LUTS in men with BPH are related to obstruction-induced changes in bladder function rather than to outflow obstruction directly. Approximately 1/3 of men continue to have significant voiding dysfunction after surgical relief of obstruction. Obstruction-induced changes are:
- Changes that lead to detrusor instability (where the bladder becomes ‘overactive’) or decreased compliance (ie how stretchy the bladder is) are clinically associated with symptoms of frequency and urgency.
- Changes associated with decreased detrusor contractility are associated with further deterioration in the force of the urinary stream, hesitancy, intermittency, increased residual urine and sometimes detrusor failure (detrusor failure means that the bladder doesn’t pump at all and that can lead to retension).
BPH (Benign Prostatic Hyperplasia): symptoms and examination
Symptoms
When man comes in, divide symptoms into voiding and storage symptoms and then other are the key symptoms we always ask about. (strangury=having to strain passing urine)
Examination
We would do a general exam but focused exam would involve–
- checking for palpable bladder
- balloting the kidneys
- checking for Phimosis (narrowing of the foreskin, so you can’t pull it back.)
- Meatal sternosis (scarring or narrowing of the opening of the urethra ie opening of the waterpipe of the glans penis)
- Then also doing a digital rectal examination, looking specifically at the size of the prostate, consistency, looking for any nodules, and also checking anal tone and sensation
Anal tone and sensation is important to check as patients with neurological problems can present with bladder symptoms similar to BPH.
BPH (Benign Prostatic Hyperplasia): Investigations
Investigations for man who presents with symptoms of BPH:
- Measure urine with dipstick
- Measure flow rate-so they have to wee into a special loop and that measures how fast they pass urine and it measures what volume of urine they pass. And also we scan their bladder after to determine the Post-Void Residual ie how much urine is left behind in the bladder (tells us how efficient the bladder is)
- Also ask them to complete questionnaires (an IPSS questionnaire is a questionnaire specifically designed to assess symptoms related to prostatic enlargement.
- Ask them to keep a Bladder diary-So that is an objective way to look at how much a patient is drinking or taking in every day, what times and what volumes, and we ask them to measure what volume of urine they’re passing. So they have to wee unfortunately, into a little plastic measuring jug and they have to write down how frequently they pass urine. And it gives us an idea of a if they’re drinking the right volume. So if they’re drinking too much, too little. Maybe the wrong things eg lots of tea, coffee or alcohol, which can be irritants to the bladder. Or maybe they’re not avoiding efficiently. Or maybe they’re voiding too frequently, which could be a sign of an infected bladder.
- Often, but not always, we perform an ultrasound of the kidneys and bladder (US KUB). So indications for this would be someone with LUTS who attended the clinic and we had evidence of either impaired renal function on blood tests, loin pain, blood in urine, or if we found a mass in kidney on exam.
- Check PSA-prostatic specific antigen is a hormone released by the prostate
- Creatinine-so to check renal function-to see if there is any effect of having too much urine in badder causing back pressure on the kidneys.
- Flexible cystoscopy-camera inside the bladder under local anaethetic, and this can help us to see if there are any bladder abnormalities, any urethral abnormalities like strictures which might be mimicking the symptoms of BPH, or if there are any bladder tumours for example.
- May also do an ultrasound scan specifically of the prostate: Transrectal ultrasound scan-done by placing a probe inside the rectum and imaging the prostate, looking specifically at the size of the prostate, so we can measure it quite accurately, but also looking for any abnormalities like calcification and any signs of prostate cancer
- Urodynamic studies-So this is a pressure flow study, where we put catheter into the urethral and a small catheter into the rectum. Then we fill up the bladder, either with normal saline or contrast, depending on the type of urodynamic test we are doing and what info we are looking for, and then we check bladder pressures so we look at the detrusor pressure and abdominal pressure and then we can see if the bladder is behaving normally or abnormally, and also whether or not there are signs of obstruction. This is actually the best way to get an accurate picture of what’s happening in the bladder and the prostate and the urethra.
BPH (Benign Prostatic Hyperplasia): Treatment
- Lifestyle changes-look at bladder diary in particular looking at what they are drinking, how much they are drinking and how often to see if there are any changes that could be done to fluid intake to improve their urinary symptoms. eg stop drinking late so don’t have to pee in the night (reduce nocturia and therefore falls in elderly). Cutting caffeine can also help.
- Alpha-1 adrenoreceptors are the main adrenoreceptors in prostate. So we can prescribe alpha-adrenergic antagonists
- These relax the bladder neck to allow easier passage of urine.
- Side effects-can make light headed as lower BP. And also can give them something called retrograde or dry ejaculation.
-5-alpha-reductase inhibitors
- They work to shrink the prostate tissue. They prevent disease progression, and reduce the risk of developing urinary retension, and the need for surgery.
- Only used if prostate is a certain size (usually over 30g)
BPH (Benign Prostatic Hyperplasia): Surgery options
- Gold standard: TURP-Transurethral resection of the prostate. Place cystoscope inside the urethra into the bladder and shave away prostate tissue
- Rezum-new treatment, inject steam into prostate
- UroLIFT-pin back prostatatic lobes
- Milin’s prostatectomy-less common nowadays-old open operation where take out very big prostates via bladder
- Can now ask radiology to embolise the prostate (so they put little coils into the vessels which provide the main blood supply to the prostate to provide shrinkage)
- HoLEP-Holmium laser enucleation of the prostate, and that is used to core out the entire prostate
1) dihydrotestosterone
2) peripheral, central and transitional (and anterior fibromuscular stroma-little slither of prostate tissue that we don’t think much about, as not much happens in terms of BPH or prostate cancer)
3) Liquefy the ejaculate
4)
- 5-alpha reductase inhibitors: finasteride, dustadteride
- alpha-adrenergic antagonists: tamsulosin, doxazosin
5) Trans-urethral resection (TURP), Rezum, Urolift, embolisation, HoLEP
UI (Urine Incontinence): epidemiology
Women with stress incontinence are less likely to seek help than women with an overactive bladder.
UI (Urine Incontinence): types of UI
Stress UI-when you lose urine on raising your intrabdominal pressure
Continuous incontinence-pathoneumoic of fistula and quite worrying
Post-micturition dribble-usually happens in males
UI (Urine Incontinence): epidemiology
Being pregnant itself can have changes to the pelvic floor and how efficient it can be and it can have changes to the bladder and urethral sphincter.
Gynaecological surgery
UI (Urine Incontinence): investigations
- urine dipstick to check for infection as sometimes UTIs can cause incontinence
- We do a flow rate and post-void residual. This is very useful to find out if someone is having overflow incontinence. If you have a high post residual-it could that they are leaking as the bladder is too full. And if they have a poor flow rate because they are only able to hold a very small amount of urine in their bladder because of urgency incontinence
- Bladder diary is very valuable
- 24 hour pad test. If patient wear pad-weigh 24 hours worth of pads and subtract one dry pad and measure the volume leaked, to find the objective volume of fluid they have leaked. Number of pads is not as useful as pad test because they could change more often etc.
- Patient symptom questionnaires
- Urodynamic studies-mainstay of diagnosis for urinary incontinence.
Stress (Stress Urinary Incontinence): what is it?
Stress (Stress Urinary Incontinence): 5 theories of causes in women
Don’t need to know
Just know the pelvic floor, bladder function and urethral sphicter, as well as the vagina and cervix play a role in maintaining continence
Stress (Stress Urinary Incontinence): Treatment for women
- Lose 5% of body weight and you can reduce riak incontinence
- stop smoking
- Bladder re-training-supervised pelvic floor training and holding on
Pharmacological treatment:
When we examine the perineum of a woman with incontinence, we look for atrophy which is a sign of low estrogen. That’s important, because there are estrogen receptors in the urethra, urethral sphincter, in the pelvic floor, in the base of the bladder and in the vagina. So all of those bits of anatomy are important in maintaining continence, and if they are not working properly because there are low estrogen levels, they aren’t able to maintain continence, so can give topical estrogen therapy.
Very unusual for us to prescribe oral medication for stress incontinence, however there is one called duloxetine, which helps to increase the closure pressure of the urethral sphincter, but it has lots of side effects, so not really a good long term option.
Stress (Stress Urinary Incontinence): Surgical treatment
If significant urinary incontinence, we’ll offer them surgery
- Bulking operations-involves injecting a product, usually collagen, in and around the urethra, to create a physical obstruction to prevent leakage.
- There are also compressive devices such as artificial urinary sphincters. This is a device more commonly used in men. Part of the device goes around the urethra to cause pressure around the urethra and thye have to press a button to actually release the pressure of the artificial sphincter to allow them to void.
- Supportive treatments, so a mid-urethral sling shown in diagram-essentially prevents too much movement of the urethra, and helps to support the urethral sphincter. And colposuspensions do a very similar thing so help support the bladder.
- In end stage cases: Ileal conduit diversion-not a good idea for a young person. Used as a last resort if nothing else worked.
Stress (Stress Urinary Incontinence): Causes in men
Type of men who get stress urinary incontinence, tend to be men who’ve had prostate surgeries so usually prostatectomies for prostate cancer, but it can also happen in men who’ve had benign prostate surgery for example TURP or HoLEPs.
3 causative theories in men:
- Weakness of external urethral sphincter
- Or you get a reduction in its length, which makes it less efficient at contracting.
- And also if they get strictures in that area
Men also have a pelvic floor based around urethral sphincter, so it’s important to think about in men too.
Levator muscles=pelvic floor
Reason why might get stress incontinence after prostatectomy is because prostate is very close to both internal and external urethral sphincter. Nerves run along lateral margins of the prostate and help to supply the external urethral sphincetr, so if remove prostate for any reason (prostate cancer or benign disease), we can cause damage to the internal sphincter (well we actually remove this in any man who has this surgery), but they will still have external spincter so works as backup unless it too gets damaged eg due to proximity to prostate or damage to nerves, that’s when they become incontinent.
Stress (Stress Urinary Incontinence): male treatments
Compressive devices such as AUS-artificial sphincters
Oral therapy again is duloxetine-not good solution in long term, only reason used for men with incontinence who are unfit for surgery.
UUI (Urge Urinary Incontinence): What is it?
Symptom syndrome of FUN
Women more likely to have urgency with leaking
Men more likely to have urgency without leaking
UUI (Urge Urinary Incontinence): differential diagnosis
Differential diagnosis
- UTI
- DO-detrusor overactivity (urodynamic diagnosis)-essentially same thing
- Urethral syndrome
- Urethral diverticulum
- Interstitial cystitis
- Bladder cancer
- Large residual volume-can cause urgency in bladder
UUI (Urge Urinary Incontinence): Treatment
Decaffeinated drinks still contain caffeine!
Here there are more options for pharmacotherapy: anticholingergics-side effects:constipation, dry mouth (feel thirsty so drink more and leak more), temporary blurred vision
beta-3-agonists have a better risk profile, but they can increase BP a bit and they can prolong QT interval so need to be aware of preexisiting cardiac issues.
UUI (Urge Urinary Incontinence): Surgical management
- PTNS-like acupuncture. Put a little needle next to the posterior tibial nerve which is alongside the ankle, and we connect that to a little machine which provides electrical stimulation. They do that once a week for 12 weeks. Don’t fully understand why it works, but it modulates bladder and urethral function and helps with urgency.
- Can inject botox into bladder under local anaethetic and repeat every 6-9 months as wears off.
- Neuromodulation-implant neuromodulation into S3 foramina and patients have a controller so they can switch it on and off. And it modulates the nervous activity of the bladder and urethral sphincter.
- Clam cystoplasty-where we open up the bladder and take a segment of bowel and the gap that we’ve created by making it into a clamshell, we cover with bowel. And this basically interupts the contractions of the bladder. But this is an open operation and there are some long term side effects that we need to be aware of.
- urinary diversion-shown in picture, where you can see the kidneys are directly draining into segment of bowel which will open into stoma bag onto the abdomen.
Session Review
