BPH Flashcards
What is benign prostatic hyperplasia
After the age of 40, the prostate becomes increasingly hyperplastic.
Benign Prostatic Hyperplasia (BPH) diagnosis is divided into microscopic (histological) BPH, macroscopic BPH, radiological, urodynamic and clinical BPH, patient impact of BPH and the quality of life (IPPS score QOL)
1. Microscopic BPH
It is the proliferation of epithelial and stromal elements i.e. fibromyoadenoma.
2. Macroscopic BPH
This refers to the enlargement of the gland as it is detected clinically by DRE ie. crude estimation of size or more accurately by transrectal ultrasound or MRI. There is strong correlation between prostate size and PSA. Several studies using International Prostate Symptom Score (IPSS), Peak Flow Rate (PFR) and Urodynamics have shown that there is no direct relationship between the size of the prostate gland and lower urinary tract symptoms (LUTS).
3. Radiological
There is elevation of base of bladder on urogram and also a large filling defect.
4. Urodynamics
PFR synchronous studies of voiding pressure and postvoid residual urine (PVR).
What is clinical BPH
This refers to the Lower Urinary Tract Symptoms (LUTS)
- urgency, frequency, nocturia Bladder Outlet Obstruction symptoms (BOO) intermittency, poor stream of urine, incomplete bladder emptying, retention of urine recurrent urinary tract infection, haematuria and renal insufficiency attributable to BPH.
The symptom of BPH are not entirely caused by the mass of the prostate gland and the dynamic increased urethral resistance. A significant portion of LUTS is caused by age and related detrusor dysfunction. Bladder outlet obstruction may induce much change in the bladder that contributes to LUTS.
Polyuria due to diabetes, renal insufficiencies, and other unrelated medical conditions may contribute to the LUTS.
What is the etiology of benign prostatic hyperplasia
It is thought that BPH is due to altered equilibrium between cell proliferation and cell death or to stem cell disease.
The aetiological factors are complex and include ageing the presence of functioning testes and normal androgen levels.
It is rare in 20-year olds and in men castrated before pubert, or with 5-alpha reductase deficiency. Others are positive familial and genetic factors, raised DHT, increase in 5-alph reductase activity, estrogen imbalance, increased epithelia cell hyperplasia, decreased cell death of epithelial and stroma cells, stromal and epithelial cells interactions, increase activity of growth factors (GF) - fibroblast GF, transforming GF, epidermal GF, keratinocyte GF, insulin like GF, endothe lial GF,-epithelial mitogens, non-androgenic testicular sub-stances, oncogenes anti-oncogenes and povision of GF bs inflammatory cell infiltrates. The cytokines produced may also cause smooth muscle contraction.
In the stem cell theory, it is postulated that abnormalities of stem cells produce amplifying cells (which are androgen independent) which in turn produce transit cells, the comma cells in prostate which are androgen-factor dependent. This leads to transient cell proliferation. The development of BPH is the result of all these factors.
Apart from its low incidence in the Japanese, the role di race and diet is not established. There is a positive correlation between lack of physical activity, obesity and LUTS and BPH
What is the pathology of benign prostatic hyperplasia
Benign prostatic hyperplasia is a fribromyoadenoma and the nodules first develop in the peri-urethral transition zone
(TZ) of the prostate near the preprostatic sphincter. All BPH nodules develop either in the TZ or in the peri-urethral region, As the disease progresses, the number of small nodules increases and they can be found in any part of the TZ and peri urethral zones unrelated to the natural enlargement of the TZ.
The capsule of the prostate gland transmits the pressure of tissue expansion due to BPH to the urethra thereby increasing the urethral resistance which produces the symptoms of LUTS (prostatism). Incision of the prostate by transurethral Collins knife improves the outflow obstruction. Dogs can develop BPH but they do not have symptoms because their prostate gland has no capsule. The size of the prostate gland does not correlate with the degree of obstruction. The symptom complex depends on the absolute size of the prostate, the dynamic urethral resistance, contraction of the smooth muscle (>60%), the prostatic capsule and the anatomical pleomorphism. Histologi-cal studies show increase in cell numbers (hyperplasia) but not hypertrophy. There is proliferation of glandular tissue and fibromuscular stroma. Gross appearance of hyperplastic tissue may show lateral and/or middle lobe enlargement and/or posterior commissural hyperplasia.
The hyperplastic nodules compress the normal periphery of the gland which forms the false capsule from which the BPH can be enucleated or resected (TURP). Depending on the relative amount of epithelial and fibromuscular tissue, the gland may be large or small and/or firm to hard. Obstruction to urine flow is due to the static component from the bulk of the glandular and fibromuscular tissue and the dynamic component due to increased contraction and tension of the smooth muscle following stimulation of the a, adrenergic nerve fibres. Blockade of the a, adrenergic nerve quickly diminishes urethral resistance and significantly improves urine flow. Androgen ablation reduces the epithelial cells and slowly decreases stromal cell numbers and marginally improves urine flow.
What are the effects of nodular hyperplasia on bladder outflow and the bladder itself
Population based studies have failed to demonstrate a clear relationship between the size of the prostate and development ofsymptoms. The term lower urinary tract symptoms (LUTS) is now used to replace “prostatism” in describing symptoms associated with BPH.
These are urgency, frequency, nocturia, intemittency, weak steam, straining, incomplete bladder empting, urinary retention; acute/chronic, recurrent UTI, haematuria etc.
Most of the knowledge of the effects of bladder outflow obstruction come from experimental animal studies. The initial response to obstruction to urinary flow clinically manifests as straining, intermittency, poor stream and incomplete bladder emptying. There is compensatory hypertrophy of detrusor smooth muscles due to increased detrusor collagen.
This is seen as thickening and coarsing of muscle strands as trabeculation with widening of gaps between them to form saccules. With continued changes, the saccules develop into diverticula. The increased muscle mass, adaptation to increased intravesical pressure and maintenance of urine flow are associated with changes in the intracellular and extracel-lular parts of smooth muscle cells. This leads to detrusor instability or decreased compliance or neural detrusor response which manifests clinically by the symptom complex of frequency, urgency and nocturia. These are the 3 irritative symptoms of IPSS. The early effects are insidious and it is often difficult for patients to perceive as due to obstruction.
These irritative symptoms can be due to carcinoma-in-situ of the bladder, tuberculosis, bilharziasis of the bladder, calculi, interstitial cystitis, urinary tract infection, chronic cystitis and other causes of bladder irritation.
Decreased detrusor contractility (atonic bladder) develops in this way. The prolonged increased contractility leads to stretching of the smooth muscles and decreased ability of the muscles to contract which leads to poor urinary stream, intermittency, incomplete bladder emptying or increased residual urine, and hesitancy. These form the obstructive symptoms of IPSS. Acute urinary retention may supervene.
Progress in decreased bladder contractility, which could cause high residual urine, also causes chronic retention with overflow incontinence which is associated with loss of sensation of the distended bladder resulting from relative enervation of bladder smooth muscles. Acute or chronic retention occurs in 20-50% of patients.
When the bladder becomes overdistended, recovery of contractility after the relief of obstruction may be impossible in which case chronic, intermittent, clean, self-catheterization is needed to effect bladder emptying. This is because prolonged indwelling bladder catheter leads to recurrent UTI from ascending infection, bladder calculi, catheter cystitis and metaplasia and squamous cell carcinoma of the bladder.
As a result of the kinking of the terminal ureters as they traverse the thickened bladder, hockey stick deformity of the terminal ureters occurs associated with failure of the uretero-vesical valves, vesico-ureteric reflux, bilateral hydroureters and hydronephrosis (Fig. 47-4abc). The increased intrapelvic pressure from hydronephrosis destroys the renal papillae nephrons and parenchyma leading to impaired renal function with resulting decreased fluid, solutes and electrolyte han-dling. This causes dehydration or oedema acidosis or acute/ chronic renal failure. Decreased erythropoietin production and/or blood loss cause anaemia.
Urinary Retention: Spontaneous acute urinary retension ( AUR) in 20 - 30 % is due to infection, overdistended bladder, excessive fluid intake, alcohol, sexual activity, debility, prostatic infarction, anaesthesia, anticholinergics or surgery.
Recurrent retention accounts for about 70% of cases for surgery. Post-micturition dribbling is the third category of LUTS (post-micturion symptoms)
What are some complications of an increasing residual urine in the bladder
a. Diverticula: Stasis and infection cause diverticulitis, calculi formation, squamous metaplasia and carcinoma.
b. Infection: Cystitis, epididymo-orchitis, prostatitis (ret-rograde spread into ejaculatory ducts or prostate), ascending pyelonephritis, pyonephrosis, renal and perirenal abscesses, bacteraemia, septicaemia, and septic shock, account for 12% of cases for surgery.
c. Calculi: Usually struvite (magnesium ammonium phos-phate) resulting from alkalinization of urine by urea splitting organisms (proteus vulgaris/pseudomonas, pyocyanea and kleb-siella) or mixed calcium oxalate/calcium phosphate calculi.
The prevalence of bladder calculi in bladder outlet obstruction is over 2% in uncatheterized patients but much higher in catheterized patients. Bladder outlet obstruction is the commonest cause of bladder calculi in adults and should be excluded and relieved when the stone is removed.
d. Urinary incontinence: It is usually secondary to chronic retention with overflow incontinence, detrusor instability and aging and may complicate operation in 4% of patients.
What are some other complications of benign prostatic hyperplasia
These are haematuria - microscopic/macroscopic - which should be investigated like all other causes of haematuria. It may be caused by varices on the trigone, infection or calculi, diverticulitis, stone in diverticulum or carcinoma of diverticu-lum. Little is known of the ultimate mortality and morbidity of BPH because of its large prevalence and lack of population based studies. However, according to WHO reports, estimates of death from BPH from 50 countries show wide variations from 1.8/100,000 in the USA with well-developed management strategies for BPH to 29.7/100,000 in the former East Ger-many; there are no available figures in the developing world.
Statistics on the bothersomeness of the symptoms on human activities such as sleep have not been properly documented.
Post obstructive Diuresis
Sudden relief of obstruction may cause hemorrhage from relief of pressure on distended veins and post obstructive divresis from decreased tubular reabsorption of fluid and/or increased solute load of urine (urea, electrolytes, glucose infusion etc.)
What is the correlation between bladder outlet obstruction by BPH and symptoms
Population-based studies have failed to demonstrate a clear relationship between the size of the prostate and the development of symptoms. The term Lower Urinary Tract Symptoms (LUTS) is now used to replace “prostatism” in describing the symptoms associated with BPH. These are urgency, fre quency, nocturia, intermittency, weak stream, straining, incomplete bladder emptying, urinary retention (acute/chronic), recurrent UTI, haematuria etc. There is little correlation between prostate size as measured by the Transrectal Ultrasonography (TRUS) and IPSS and the degree of bladder outlet obstruction as measured by (PFR/QMAX) and urodynamics pressure flow studies.
What are some clinical features of benign prostatic hyperplasia
Symptoms
The primary diagnostic challenge is to establish that the symptoms are due to BPH and not to the pathological processes of ageing or other conditions such as urethral stricture, prostate cancer, etc.
1. Initial recognition
The early presentation of BPH is insidious and may not be noticed by the patients. They are recognized early by a yes answer to any of these 3 questions:
i)
do you get up at night to pass urine?
is your urine flow slow?
iii) are you bothered by your bladder function?
2. Irritative symptoms
These occur early and they are: a.
Frequency.
b. Urgency.
c.
Nocturia and.
Urge incontinence.
They have great impact on the quality of life of patients and may occur in other urinary tract pathologies such as urinary tract infection (UTI), tuberculosis, carcinoma-in-situ, bladder stones, interstitial cystitis, chronic vesical schistosomiasis, carcinoma of the prostate/or bladder, chronic prostatitis, neurogenic bladder, diabetes mellitus etc.
3. Obstructive (voiding) symptoms
These are:
a. Weak (poor) stream. b.
Feeling of incomplete bladder emptying.
C.
Straining on micturition.
d. Intermittency.
Others are:
a.
Difficulty of micturition associated with difficulty with starting micturition (hesitancy)
b.
Prolonged micturition
c. Urinary retention
This may be acute/acute on chronic or chronic.
Acute/Acute-on-Chronic.
There is sudden cessation of urination associated with painful suprapubic mass. Episodes of acute retention may be precipitated by sympathomimetic or anticholinergic drugs (e.g. Probanthine, Oxybutynin), infarct of the prostate, diuresis from diuretics, alcohol etc., or postponement of urination for long periods especially during travelling.
il) Chronic urinary retention with overflow incontinence
(“Enuresis”)
Post urination dribbling may also occur due to slow painless distension of the bladder from increasing residual urine.
- Others
a. Haematuria - Microscopic/macroscopic. This could be due to rupture of distended veins of bladder mucosa covering the prostate or infection, caleuli etc. It should be investigated to exclude other causes such as UTI, calculi, cancers of bladder, prostate, ureters kidneys by CT urogram, cystoscopy urinaly-sis.
b. Recurrent UTI such as cystitis, epididymo-orchitis, pyelonephritis, bacteraemia, septicaemia etc.
c. Renal failure - This could be acute or chronic - associated with thirst, lethargy, headaches, uraemia.
What are some differential diagnosis of symptoms of benign prostatic hyperplasia
Lower Urinary Tract Symptoms
- Obstructive Symptoms/Voiding Symptoms
These are incomplete emptying, intermittency, poor stream, straining and retention of urine. The differential diagnosis include:
і) BPH.
it) Urethral stricture il) Carcinoma of prostate.
iv) Bladder cancer of bladder neck.
v) Bladder calculi.
vi Phimosis/Paraphimosis.
vil) Neurogenic bladder.
vin Meatal stenosis
The diagnosis is confirmed by excluding these by history, fill clinical examination and complete urological work up.
What are the guidelines for diagnosis of benign prostatic hyperplasia
- Ask the 3 questions:
Do you get up at night to pass urine? il) Do you have problems of urine flow? iii) Is your bladder bothersome?
If the answer to any of these is yes, then the patient has significant lower urinary tract symptoms and so the IPSS score (Table 47-1) is determined. The relevant medical history include medications - diuretics, aspirin, antihypertensives - diabetes mellitus, previous STU, operations and neurological disorders etc.
What are some physical examinations to perform on a person suspected with BPH
General Examination
Anaemia, edema and dehydration are looked for. The cardiovascular system for hypertension and the chest are examined. The abdomen is examined for hernia, palpable bladder, kidneys, liver, ascites, palpable masses etc. The genitalia and penis are examined for evidence of urethral discharge, urethral stricture, meatal stenosis, perineal swell-ings, indurations, fistulae, extravasation of urine, water can serotum etc. Phimosis, paraphimosis meatal stenosis and meatal warts are looked for and the urethra palpated for induration and other abnormalities. The scrotum is examined.
Focused neurological examinations is performed. Digital rectal examination (DRE) is performed after urination and post-void residual urine (PVR) estimated. DRE is preceded by inspection and estimation of sphincter tone. The prostate is felt anteriorly for tenderness and its size (normal 20g when it is just palpable). If the finger cannot define the edges, it is estimated over 50g. The surface, mobility of the overlying rectal mucosa, the presence of median sulcus, consistency of the prostate and its symmetry are assessed. For more accurate determination of the prostate size for deciding the form of surgery, either TURP or open prostatectomy or TRUS prostate size determination is used.
Physical examination is done to rule out a neurological cause of the presenting symptoms.
What is the definition of the consistency of the prostate and its diagnosis
i) In BPH, the prostate feels smooth, elastic (rubbery). il) Cancer of prostate may feel normal (TI), indurated, asymmetrical, hard with a palpable nodule, nodular, woody hard with obliterated median sulcus and a fixed overlying rectal mucosa, and in advanced cases fixation to the surrounding structures and organs.
iii) Prostatic abscess feels exquisitely tender when acute, bulky and fluctuant. A chronic abscess may not be tender. iv) In prostatitis, the acute form is exquisitely tender but
the chronic form is hard and indurated.
y The differential diagnosis of a hard prostate includes cancer, calcified/fibrotic prostate, TB of the prostate, schistosomiasis of the prostate, granulomatous prostatitis etc.
vi) Fixity of the prostate to adjacent organs - the mucosa overlying the prostate and other structures - is determined. The seminal vesicles are felt only when diseased.
The key to an accurate DRE is a good and gentle technique mastered over a long period and thinking about what the finger is doing and feeling throughout the procedure. The positive predictive value of a palpable nodule being cancer is 30%. The positive predictive value of a palpable nodule for cancer rises with levels of PSA over 4ng/ml. A palpable cancer of the prostate gland may be present with normal PSA values, if due to TCC, neuroendocrine or anaplastic disease. A normal PSA and a normal DRE indicate that there is no significant cancer.
There is some evidence that DRE causes a rise in PSA values though not signficantly. It is therefore preferable to take blood for PSA before DRE.
What are some investigations to make in a patient with benign prostatic hyperplasia
- Urinalysis: (Dipstick or spun sediment examination)
Complete examination on midstream specimen of urine (MSU) is done for pH, sugar, proteins, crystals, culture and sensitiv-ity, microscopy for RBC, WBC, casts, crystals, bacteria and malignant cells.
Sequential bacteriological urinalysis of voided urine- Ist portion (VI), V2 (MSU), EPS (expressed prostatic secretions) and post massage V3 are performed and the specimens examined to exclude prostatitis. - Full Blood Count, sickling and haemoglobinopathy.
- Serum creatinine is done in case there is renal insuffi-ciency. 13.4% of patients with symptomatic BPH have renal insufficiency.
- BUE, blood urea and electrolytes are checked to exclude renal insufficiency and any imbalances.
- Serum PSA (Normal 0-4ng/ml) in < 60 years. PSA, preferably fasting blood specimen is done to exclude early prostate cancer. It is elevated in prostate cancer, BPH, prostatitis, prostate infarct and prostatic injury such as prostatic biopsy etc. The rise of PSA above 4ng/ml is an indication for prostatic biopsy, preferably by transrectal ultrasound (TRUS) Trucut biopsy technique. Other abnormalities of the PSA suchas density > 0.15ng/ml or velocity > 0.75ng/ml per year are indications for prostatic biopsy.
- Additional Diagnostic Tests: Patients with normal initial evaluation and IPSS scores under 8 and normal PSA do not need additional investigations but are managed by watchful waiting i.e. by regular IPSS, DRE, and PSA estimations.
- Men With Serious Complications: Patients with IPSS score over 19,complications due to BPH such as refractory urinary retention (acute/chronic), recurrent UTI, recurrent gross haematuria, bladder stones, renal insufficiency or large diverticula should be investigated for treatment by medications or surgery (TURP/TUIP/Open prostatectomy). PFR and pressure flow urodynamic studies are not possible if the patient cannot micturate or wears a urethral catheter.
- Infection, Haematuria, Stones: Presence of these requires appropriate investigations - such as MSU, abdominal ultrasonography, plain abdominal X-ray, IVU or CT scan and urethrocystoscopy before treatment of BPH.
- Urine Flowrate, Post-void Residual Urine, Pressure Flow Urodynamics: These tests are recommended in patients with moderate to severe symptoms - IPSS 8 - 20 - where decisions have to be taken on modalities of treatment.
What are some differential diagnosis of BPH
- Urethral Stricture (US): There is usually a history of gonococcal or sexually transmitted urethritis or urethral injury. Passage of a size 20Ch silicone urethral catheter under sterile conditions will be held up at the site of the stricture in the penile or bulbous urethra. An urethrosonography or retrograde urethrocystogram shows narrowing or complete obstruc-fion at the point of the stricture. Urethral stricture can co-exist with BPH in the same patient; in such cases the urethral stricture is treated by internal urethrotomy or urethroplasty before the treatment of the BPH.
- Carcinoma of the prostate: DRE may reveal normal or indurated, palpable nodule, asymmetry and/or a hard prostate. The PSA is usually over 4ng/ml. Diagnosis is best confirmed by TRUS-guided sextant biopsy using an automated gun. Digital-directed transrectal Trucut biopsy is an option but sampling for carcinoma by this method is not as accurate as TRUS-guided biopsy.
- Bladder Neck Obstruction: The patient is relatively young. The prostate is of normal size and texture by DRE and TRUS assessment. PFR is less than 10ml/sec and urethroscystoscopy shows normal size prostate trabeculated bladder but tight bladder neck.
- Carcinoma Of The Bladder Neck: There may be microscopic or macroscopic haematuria but this may be absent in 20% ofcases. The other features are urgency and frequency incarcinoma-in-situ; urinary retention and a palpable bladder mass are late presenting features. Diagnosis is by positive urine cytology, pelvic ultrasonography, urethrocystoscopy and biopsy.
Bladder Calculus - Neurogenic Bladder: This may be due to multiple sclerosis, multiple systems atrophy, brain lesions, prolapsed intervertebral disc, lesions of the spinal cord, spina bifida and myelomeningocele. Lower urinary tract symptoms may be present. Other stigmata of neurological conditions will be present such as paraesthesia of the perineum, poor anal tone, paraparesis, etc. The prostate feels- normal and urethrocystoscopy reveals absent bladder neck pathology. PFR will be < 10ml/sec and urodynamics or cystometry confirms the diagnosis. Neurogenic bladder and BPH can co-exit in the same patient. Detrussor muscle sphincter dyssynergia presents like neurogenic bladder.
- Diabetes Mellitus: It may present with lower urinary tract symptoms of urgency, frequency and nocturia. In addition, there will be polydipsia and polyuria. There is sugar in the urine, and hyperglycaemia. Symptoms disappear when the diabetes is controlled by diet, oral hypoglycaemics/insulin but diabetes mellitus can co-exist with obstructive BPH, carcinoma of the prostate, urethral stricture or neurogenic bladder.
- Systemic Causes of lower urinary tract symptoms include ageing, psychiatric disorders such as depression, diuretics, chronic renal failure, polydipsia and excessive consumption of beverages such as tea and coffee and water.
- Depression: Some patients with depression lie awake at night and so may urinate frequently. The IPSS and the PFR are normal. The prostate gland is normal on DRE is normal and there is no significant post-void residual urine on pelvic ultrasonography and IVU.