Benign Prostatic Hyperplasia Flashcards
What is Benign Prostatic Hyperplasia (BPH)?
Benign prostate enlargement (BPE) is an enlargement of the prostate gland which is most often due to benign prostatic hyperplasia (BPH). BPH is a histological diagnosis and is characterised by non-cancerous hyperplasia of the glandular-epithelial and stromal tissue of the prostate leading to an increase in its size.
Who is commonly affected by BPH?
BPH is very common and the risk increases with age; approximately 40% of men over 50 years have evidence of enlargement, rising to 90% of men over 80 years.
What is the most common cause of lower urinary tract symptoms (LUTs)?
BPH is the most common cause of Bladder Outlet Obstruction in men and hence can be considered the most common cause of Lower Urinary Tract Symptoms (LUTS) in men.
Briefly describe the pathophysiology of BPH
The prostate is a gland found in the male reproductive system which produces prostatic fluid.
The exact mechanism of benign prostatic hyperplasia has not been identified. However, it is clear that androgens play a role particularly in the development in the gland during adolescence and the future development of BPH.
Unlike other androgen dependent organs in the body, the prostate converts testosterone to dihydrotestosterone (DHT) using the enzyme 5α-reductase. DHT is more potent and accounts for 90% of androgen in the tissue. Also, unlike other tissues, the prostate retains the ability to respond to testosterone and thus levels of DHT also remain high though life.
What are the risk factors for BPH?
Age is the primary risk factor for developing BPH. Other risk factors include family history (first degree relatives), Afro Caribbean ethnicity and obesity.
What are the clinical features of BPH?
Patients with benign prostatic hyperplasia will generally present to primary care with lower urinary tract symptoms (LUTS), either voiding symptoms (hesitancy, weak stream, terminal dribbling, or incomplete empyting) or storage symptoms (urinary frequency, nocturia, nocturnal enuresis, or urge incontinence). Other less common symptoms can include haematuria and haematospermia.
A Digital Rectal Examination (DRE) is essential in order to help distinguish BPH from prostate cancer. A firm, smooth, symmetrical prostate is a reassuring sign (a more rounded prostate of greater than two finger widths may indicate enlargement).
As part of the initial assessment, every patient should also complete an International Prostate Symptom Score (IPSS) questionnaire.
Briefly describe The International Prostate Symptom Score for prostate cancer
The IPSS is a validated screening tool used in the evaluation and quantification of LUTS.
A score of 0-5, with 0 being ‘never’ and 5 being ‘almost always’, is assigned by the patient to each of the following questions. Scores of 0-7 are mild, 8-19 moderate and 20+ severe.
Each question begins with “Over the past month how often have you…”
- Had the sensation of not emptying your bladder completely after you finish urinating? (incomplete emptying)
- Had to urinate again less than two hours after you finished urinating? (frequency)
- Found you stopped and started again several times when you urinated? (intermittency)
- Found it difficult to postpone urination? (urgency)
- Had a weak urinary stream? (weak stream)
- Had to push or strain to begin urination? (straining)
- Most typically get up to urinate from the time you went to bed at night until the time you got up in the morning? (nocturia)
There is one further question rated 0-6 for the following on Quality of Life and is not included in the overall score:
- If you were to spend the rest of your life with your urinary condition just the way it is now, how would that make you feel?
What investigations should be ordered for BPH?
A urinary frequency and volume chart should be completed by all patients with bothersome LUTS.
Bedside urinalysis should always be performed to exclude urinary tract infection. A post-void bladder scan can be helpful in assessing any significant chronic retention present
Depending on the findings from the DRE, a Prostate Specific Antigen (PSA) may be warranted in order to evaluate any malignant pathology, however is often marginally elevated in BPH even in the absence of malignancy.
An ultrasound scan of the renal tract can also be used to calculate the volume of the prostate alongside assessment of the rest of the renal tract for urinary retention or hydronephrosis. Any prostate >30ml (volume calculated by width x height x length x 0.52) is deemed enlarged.
Urodynamic studies can give objective measurements related to reported symptoms, including bladder contractility, flow rate, and storage capacity. The bladder outlet obstruction index (BOOI) can help diagnose obstructive voiding related to BPH.
Briefly describe the conservative management of BPH
For patients who have an incidental identification of benign prostatic hyperplasia, with no clinical features of the condition nor of any significant complications, many patients can simply be reassured and advised BPH is not a cause for significant concern.
Asking patients to keep a symptom diary, providing a medication review (especially iatrogenic causes of LUTS), and giving suitable lifestyle advice (e.g. moderating caffeine and alcohol intake) are helpful conservative options that can be done for all patients.
Briefly describe the medical management of BPH
Most men with symptomatic BPH should initially be trialled on an α-adrenoreceptor antagonist (α-blockers), such as tamsulosin.
They provide a symptomatic benefit within a few days and their response rate to this treatment is thought to be around 30-40%; those who do respond can expect approximately a 4-point improvement in their IPSS.
For those that remain symptomatic despite α-adrenoreceptor antagonists, 5α-reductase inhibitors, such as Finasteride, are often then trialled. They act to prevent the conversion of testosterone to DHT, resulting in a decrease in prostatic volume.
What is the mechanism of action of α-blockers?
They act by relax prostatic smooth muscle via blockade of α-adrenoceptors, thus reducing the dynamic component.
What are the side effects of α-blockers?
Significant side effects are associated with alpha blockers, such as postural hypotension, retrograde ejaculation and Floppy Iris Syndrome (occurs intra-operatively in those undergoing cataract surgery).
What is the mechanism of action of 5α-reductase inhibitors?
They act to prevent the conversion of testosterone to DHT, resulting in a decrease in prostatic volume.
Briefly describe the surgical management of BPH
Patients who are refractory to medical management or develop a significant sequlae of benign prostatic hyperplasia (e.g. high pressure retention) will be referred for potential surgical management.
A wide range of surgical procedures are available, most commonly of which performed is the TURP procedure.
What is TransUrethral Resection of the Prostate (TURP)?
A TransUrethral Resection of the Prostate (TURP) is the most widely used procedure undertaken to manage BPH, involving endoscopic removal of obstructive prostate tissue using a diathermy loop to increase the urethral lumen size.
It has excellent clinical outcomes, many patients having significant clinical improvement within a few months.
