BPH Flashcards
1. Identify and name the major anatomic and histologic features of the prostate gland (MKS1a/knowledge) 2. Identify the predominant location in the prostate where BPH develops and describe how this fact relates to the symptoms and signs of BPH (MKS-1b) 3. Describe the distinctive epidemiological features and natural history of BPH (MKS-1b) 4. List the symptoms and signs of BPH (MKS1c&d/knowledge) 5. List the indications for treatment of BPH(MKS1e/knowledge and MKS3d/clinical reasoning) 6.
What are the different zones of the prostate? Which one gives rise to BPH? Which one is most likely to give rise to cancer?
- There are 3 basic anatomic regions of the prostate:
- the anterior prostate
- central gland and
- peripheral gland
- The anterior prostate is entirely fibromuscular and non-glandular, and it appears to have little significance in prostatic function or pathology
- This area comprises approximately 20% of the bulk of prostatic tissue.
- The central gland is composed of the proximal urethra, the prostate tissue around the posterior urethra and the smooth muscle of the internal sphincter
- It forms the central portion of the prostate and extends from the base of the prostate to the verumontanum.
- The transition zone surrounds the urethra, and although this region accounts for only 10% of prostate glandular tissue in young men, it exhibits significant growth with age.
- Indeed, it is in the transition zone is where benign prostatic hypertrophy (BPH) develops
- The peripheral gland or zone is composed entirely of acinar tissue. It comprises the posterior surface of the prostate, including the apical, lateral, posterolateral and anterolateral portions of the prostate.
- The peripheral zone represents approximately 70% of glandular volume in the normal adult prostate.
- The vast majority of prostatic carcinomas arise in this region of the prostate
What are some of the major symptoms that accompany BPH?
- The term “benign prostatic hyperplasia (BPH)” has been used to describe a constellation of voiding symptoms that occur in men with aging.
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These symptoms include:
- decreased force of stream
- hesitancy
- straining
- incomplete bladder emptying
- and nocturia
- Such symptoms are generally referred to as obstructive in nature.
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Irritative symptoms are also associated with BPH and include:
- urinary frequency
- urgency
- occasionally dysuria
- BPH has been used synonymously with “prostatism” and “bladder outlet obstruction”, implying that obstruction to urinary outflow, secondary to prostatic enlargement, is the cause of such symptoms
- More recently, it has been recognized that prostatic enlargement is not necessary for such symptoms.
- Furthermore, women may experience similar symptoms with age
- Thus, “lower urinary tract symptoms” (LUTS) is currently the preferred term to describe this complex of obstructive and irritative urinary symptoms that occur in both sexes with age
What are the common causes of voiding dysfunction in men?
- Voiding dysfunction in the aging male may be due to a variety of factors including changes in the bladder, prostate and/or urethra
- Intrinsic changes in the bladder, such as bladder instability, decreased bladder compliance and decreased bladder capacity may all lead to LUTS.
- However, in many men these symptoms are due to BPH.
- With age, the prostate exhibits glandular enlargement, increased smooth muscle tone and decreased compliance secondary to altered collagen deposition
- these changes can lead to altered urinary symptoms.
- Urethral stricture and bladder neck contracture are other forms of obstruction or blockage that can present with similar symptoms
What is the epidemiology of BPH?
- BPH is one of the most frequent diagnoses leading to urology referral.
- It begins to develop before age 30 with almost 10% of men having histologic evidence of BPH by 40 years of age, and 50% of men showing evidence by age 60
- Overall, nearly 80% of men will develop BPH, and as many as 30% will receive treatment for it
- In studies that examine the natural history of BPH, the incidence of acute urinary retention or the development of a significant post-void residual urinary volume is 2% per year
- Thus, the burden of BPH on the healthcare system is substantial
How is BPH diagnosed? How are treatment parameters decided?
- After excluding other causes of LUTS, both objective and subjective parameters are used to decide whether or not treatment is indicated
- Objective parameters include determination of:
- prostate size
- measurement of urinary flow rate
- determination of the post-void residual urine volume
- Although several subjective instruments are available to quantify the severity of LUTS, the American Urological Association Symptom Score Index (AUASI) also known as the International Prostatic Symptom Score (IPSS) is used by most clinicians.
- This questionnaire consists of 7 items that determines the severity of irritative and obstructive voiding symptoms
How is symptom severity assessed in BPH?
- Symptom severity related to:
- urinary frequency
- nocturia
- weak urinary stream
- hesitancy
- intermittency
- incomplete bladder emptying
- urinary urgency are assessed
- On a scale of 0-35:
- mild symptoms exist with scores of 0-7
- moderate symptoms with scores of 7-15
- severe symptoms with a score of >15
- This index demonstrates predictive validity, reliability and internal consistency
- There is some correlation between the objective and subjective measures in that the lower the peak urinary flow rate, the more severe the urinary symptoms and the larger the prostate
- Using the AUA Symptom score and the information from the clinical evaluation, treatment options can be reviewed
What are the signs and symptoms that alter the treatment algorith for BPH?
- Importantly, there are several signs or symptoms that may coexist with voiding symptoms that can alter the treatment algorithm
- If the patient has urinary retention, an acute condition in which urine is unable to be voluntarily voided, then immediate treatment with surgery may be indicated
- A trial of Foley catheter or clean intermittent catheterization and alpha blocker medication may avoid surgical treatment in the future in about 80% of cases in which retention coexists with LUTS
- Recurrent urinary tract infections, persistent or recurrent gross hematuria, and bladder stones are also coexisting conditions that may necessitate surgical instead of medical treatment
What drug therapies are available to treat BPH?
- Medical therapy for BPH attempts to shrink or stop the growth of the prostate or open the urethral channel within the prostate, without using surgery
- The FDA has currently approved 6 drugs to relieve the symptoms associated with an enlarged prostate
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Finasteride, FDA-approved in 1992, and dutasteride, FDA-approved in 2001, inhibit production of the hormone dihydrotestoterone (DHT), which is responsible for growth of the acinar glands of the prostate
- These drugs can either prevent progression of growth of the prostate or actually shrink the prostate in some men
- The drugs terazosin, doxazosin, tamsulosin, and alfuzosin are also used to treat BPH
- These drugs belong to the class known as alpha blockers, and all act by relaxing the smooth muscle of the prostate and bladder neck to improve urine flow and to reduce bladder outlet obstruction
What is the efficacy of the alpha blockers in the treatment of BPH?
- Terazosin and doxazosin were developed as blood pressure pills, but tamsulosin and alfuzosin were developed specifically to treat BPH.
- There is excellent clinical trial data that shows that finasteride and doxazosin together is more effective than using either drug alone to relieve symptoms and prevent BPH progression
- The dual-drug regimen reduced the risk of BPH progression by 67 percent, compared with 39 percent for doxazosin alone and 34 percent for finasteride alone
List the different types of minimally invasive therapy for BPH.
- Because drug treatment is not effective in all cases, a number of minimally invasive procedures have been developed to relieve BPH symptoms
- In general, these procedures are less invasive than conventional surgery for BPH:
- Transurethral microwave procedures
- Transurethral needle ablation (TUNA)
- Water-induced thermotherapy
- High-intensity focused ultrasound (HIFU)
What are transurethral microwave therapy for BPH?
- This device uses microwaves to heat and destroy excess prostate tissue
- In the procedure called transurethral microwave thermotherapy (TUMT), the device sends microwaves through a catheter to heat selected portions of the prostate to at least 111 degrees Fahrenheit
- A cooling system protects the urinary tract during the procedure
- The procedure is performed on an outpatient basis in an hour without general anesthesia
- TUMT has not been reported to lead to erectile dysfunction or incontinence
- Although microwave therapy does not cure BPH, it reduces urinary frequency, urgency, straining, and intermittent flow. It does not correct the problem of incomplete emptying of the bladder
- The long-term effects of microwave therapy are still not clear however
Describe the role of Transurethral needle ablation (TUNA) in BPH therapy.
- The TUNA system delibers low-level radiofrequency energy through twin needles to burn away selected regions of the enlarged prostate
- Shields protect the urethra from heat damage
- The TUNA system improves urine flow and relieves symptoms with fewer side effects when compared with conventional surgery, transurethral resection of the prostate (TURP)
- No incontinence or impotence has been observed with this procedure
What is the role of water-induced therapy in the treatment of BPH?
- This therapy uses heated water to destroy excess tissue in the prostate
- A catheter containing multiple shafts is positioned in the urethra so that a treatment balloon rests in the middle of the prostate
- A computer controls the temperature of the water, which flows into the balloon and heats the surrounding prostate tissue
- The system focuses the heat in precise regions of the prostate, while surrounding tissues in the urethra and bladder are protected
- Destroyed tissue either escapes with urine through the urethra or is reabsorbed by the body
What is the role of high-intensity focused ultrasound (HIFU) in the treatment of BPH?
- The use of low frequency ultrasound waves to destroy prostate tissue is the youngest of the minimally invasive therapies developed for BPH
- It appears as safe as other minimally invasive methods but long term outcome data is not available as yet
List the conventional surgical therapies for BPH?
- Transurethral resection of the prostate (TURP)
- Transurethral Incision of the Prostate (TUIP)
- Transurethral laser surgery