Health

Benign Prostate Hypertrophy: Pathophysiology, Clinical Features, Diagnosis & Treatment

By April 1, 2017 No Comments

Benign prostate hypertrophy  (BPH) is one of the most common diseases in aging men. It can cause bothersome lower urinary tract symptoms that affect the quality of life by interfering with normal daily activities and sleep patterns as well as sexual life. BPH usually occurs in men older than 40 years of age. By the time they reach 60 years of age, almost 50% of men have BPH. It affects as many as 90% of men by 85 years of age. BPH is the second most common cause of surgical intervention in men older than 60 years of age.

The prostate gland is a small gland, it weighs about 25 grams in an adult. It is situated at the neck of the bladder and encircles the urethra. In BPH the gland enlarges sufficiently to compress the urethra and causes urinary obstruction, hydronephrosis, hydroureter and urinary tract infection.

Pathophysiology of Benign Prostate Hypertrophy

The main cause of BPH is not well understood or is unknown. However, decrease level of testicular androgens has been implicated. Dihydrotestosterone (DHT), a metabolic of testosterone, is a critical mediator of prostate growth. Estrogens may also play a role in the cause of BPH. BPH generally occurs when men have elevated estrogens level and when prostate tissue becomes more sensitive to estrogens and less responsive to DHT. BPH develops over a prolonged period; changes in the urinary tract are slow and insidious. BPH is a result of complex interactions involving resistance in the prostatic urethra to mechanical and spastic effects, bladder pressure during voiding, detrusor muscle strength, neurologic functioning and general physical health. The hypertrophied lobes of the prostate may obstruct the bladder and urinary retention.

Some of the risk factor for Benign Prostate Hypertrophy are…

Diet (high in animal fat and protein and refined carbohydrates, low in fiber) increases the risk for BPH.

Clinical features of  Benign Prostate Hypertrophy

BPH may or may not lead to lower urinary tract symptoms; if symptoms occur, they may range from mild to severe which increases with age, and half of the men with BPH report having moderate to severe symptoms.

  • The prostate is large, rubbery and non-tender. Prostatism (obstructive and irritative symptoms complex) is noted.
  • Obstructive and irritative symptoms may include increased urinary frequency, urgency, nocturia, hesitancy in starting with urination, decreased and intermittent force of stream and the sensation of incomplete bladder emptying, abdominal straining with urination.
  • The decrease in the volume and force of the urinary stream, dribbling  (urine dribbles out after urination), and complications of acute urinary retention (more than 60 ml of urine remaining in the bladder after urination) and recurrent UTIs.
  • Ultimately, chronic urinary retention and large residual volumes can lead to azotemia (accumulation of nitrogenous waste products) and renal failure.
  • Generalized symptoms may also be noted, including fatigue, anorexia, nausea, vomiting and pelvic discomfort.
  • Other disorders that produce similar symptoms include urethral stricture, prostate cancer, neurogenic bladder and urinary bladder stones.

Diagnostic investigation

  • The health history focuses on the urinary tract, previous surgical procedures, general health issues, family history of a prostate disease and fitness for possible surgery.
  • Physical examination, including digital rectal examination  (DRE).
  • Urinalysis to screen for haematuria and UTI.
  • Prostate-specific antigen (PSA) level is obtained if the patient has at least a 10 years life expectancy and for whom knowledge of the presence of prostate cancer would change management.
  • Urinary flow-rate recording and the measurement of post-void residual (PVR) urine.
  • Urodynamic studies, urethrocystoscopy, and ultrasound may be performed.
  • Complete haematology and biochemistry test.

Treatment of  Benign Prostate Hypertrophy

The goals of treatment of BPH are to improve quality of life, improve urine flow, relieve the obstruction, prevent disease progression and minimize complications. The treatment depends on the severity of symptoms, the cause of disease, the severity of the obstruction and the patient’s condition. Treatment measures include the following:

  • Immediate catheterization if the patient cannot void (a urologist may be consulted if an ordinary catheter cannot be inserted). An incision into the bladder  (suprapubic cystostomy) may be needed to provide urinary drainage.
  • “watchful waiting” to monitor disease progression.

Other therapeutic choices include pharmacologic treatment, minimally invasive procedures, and surgery.

Pharmacologic therapy

Pharmacologic treatment of BPH includes the use of alpha-adrenergic blockers and 5-alpha-reductase inhibitors. The alpha-adrenergic blockers which include alfuzosin (Uroxatral), terazosin (Hytrin), doxazosin (Cardura), and tamsulosin, relax the smooth muscle of th3 bladder neck and prostate. This improves urine flow and relieves symptoms of BPH. Side effects include dizziness, headache, fatigue, postural hypotension, rhinitis, and sexual dysfunction.

Another treatment involves hormonal manipulation with antiandrogen agents. The 5-alpha-reductase inhibitors, finasteride (Proscar) and dutasteride (Avodart), are used to prevent the conversion of testosterone to DHT and decrease prostate size. Common side effects include decreased libido, Ejaculatory and erectile dysfunction, gynecomastia (breast enlargement in males) and Flushing.

Surgical intervention

Minimally invasive therapy

Several forms of Minimally invasive therapy may be used to treat BPH. Transurethral microwave heat treatment  (TUMT) involves the application of heat to prostatic tissue. A transurethral probe is inserted into the urethra, and microwaves are directed to the prostate tissue. The targeted tissue becomes necrotic and slough. To minimize damage to the urethra and decrease the discomfort from the procedure, some systems have a water-cooling apparatus.

Another option includes transurethral needle ablation (TUNA) by radio frequency energy and the UroLume stent. It uses low-level radio frequencies delivered by thin needles placed in the prostate gland to produce localized heat that destroys prostate tissue while sparing other tissues then the body resorbs the dead tissue. But this method is only for patients with urinary retention and in patients who are poor surgical risks.

Surgical Resection

Surgical resection of the prostate gland is another option for patients with moderate to severe lower urinary tract symptoms of BPH and for those with acute urinary retention or other complications. If surgery is to be performed, all clotting defects must be corrected and medications for anticoagulation withheld because bleeding is a complication of prostate surgery.

Transurethral resection of the prostate  (TURP) is the benchmark for surgical treatment of BPH. It involves the surgical removal of the inner portion of the prostate through an endoscope inserted via urethra; no external skin incision is made. The treated tissue either vaporizes or becomes necrotic and slough.

Open prostatectomy involves the surgical removal of the inner portion of the prostate via a suprapubic, retropubic or perineal (rare) approach for large prostate glands. Prostatectomy may also be performed laparoscopically.

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