Benign Prostatic Hyperplasia

Fig 1. BPH causes compression of the urethra leading to bladder obstruction.

Key points:

  • BPH usually begins at the age of 50 years
  • The initial symptoms are that of frequent urination followed by difficulty and dribbling at end of the stream
  • If untreated, the enlarged prostate can lead to painful, acute retention of urine and obstructed kidneys
  • Medication is the first-line treatment and effective in up to 80% of cases

BPH is the benign enlargement of the prostate. The prostate gland is a small organ the size of a walnut that sits just below the bladder and surrounds the urethra. It produces fluid for nourishment of sperms. However, after the age of 50 years, it tends to enlarge and compress the urethra. This causes obstruction and irritation of the bladder leading to symptoms like slow / intermittent stream, and urinary frequency both day and night. BPH is assessed from the history, physical examination, ultrasound and uroflow investigations. Left untreated, the consequences are: bladder weakness, urine infections, bladder stones and even kidney failure. Many men mistaken the symptoms to be due to ageing. However, the enlarged prostate (be it benign or cancerous) needs to be excluded before assuming that the bladder symptoms are age-related.

Assessment of BPH:

1.International Prostate Symptom Score (IPSS) [Fig 1]. This is a questionnaire that covers the symptoms caused by the enlarging prostate. The total score gives an indication of the severity of the prostatic symptoms and how bothersome it is..

Fig 1. IPSS is a questionnaire to determine the severity of the prostate symptoms

2.Physical examination [Fig 2]. The abdomen is examined for any bladder distension and a rectal exam (DRE) done to feel the consistency of the prostate and estimate its size. The DRE is also part of the examination in detecting prostate cancer.

Fig 2. Digital rectal exam (DRE) is done to assess the prostate size and shape

3. Prostate Specific Antigen (PSA). This is a blood test to detect prostate cancer. It should not exceed 4 ug/L. If so, prostate cancer should be excluded by means of a transrectal ultrasound guided biopsy (TRUS/Bx).

4. Ultrasound [Fig 3]. A prostate ultrasound gives an image of the prostate shape, prostate volume, and cslculating the post-void residual urine volume. A prostate size of > 20 ml and residual urine of > 100 ml is considered as abnormal. Ultrasound of the kidneys can also determine any blockage (hydronephrosis).

Fig 3. Ultrasound of the bladder and prostate to measure the prostate size and residual volume in the bladder

5. Uroflow [Fig 4]. The uroflow is a functional test that measures the speed of the urine flow. A transducer in the machine records and converts the flow into a graph to give an indication of the degree of bladder blockage.

Fig 4. Uroflow machine is used to measure the speed of urine flow
a) Normal Uroflow Pattern
b) Obstructed Uroflow Pattern

This is cuComplications of BPH [Fig 5]

BPH can be a progressive disease. Left untreated, it can lead to bladder blockage and cause high residual urine which in turn lead to urinary infections and formation of bladder stones. As the blockage become worse, the kidneys get swollen (hydronephrosis) and ultimately, the sudden inability to pass urine. At this stage, surgery using a resectoscope is needed to remove the enlarged prostate (called TURP).

Fig 5. Complications arise when the enlarged prostate causes retention of urine

Treatment of BPH

Medical therapy is the first-line treatment. There are 2 main groups of drugs available. The first are the alpha1-blockers, (eg. terazosin, alfuzosin, tamsulosin) which relax the muscle tone around the prostate and bladder neck. They are 70 to 80% effective, but have a 10% risk of causing giddiness due to lowering of the blood pressure. However, they do nothing to reduce the prostate size. The second group are the 5-alpha reductase inhibitors, (eg. finasteride, dutasteride) which blocks the male hormone, dihydrotestosterone (DHT) within the prostate and thereby, shrink the prostate. They are indicated for large glands (> 30 ml size) but because the drug can take up to 3 months to effecively reduce the prostate size, alpha1-blocker drug is given for the initial months.

Surgery is indicated when complications arise or when medical treatment fail. The most effective surgery is TURP, which is endoscopic resection of the obstructing prostate to recreate an open channel [Fig 6]. It can be done under spinal anaesthesia and takes 1 hour to do. Hospital stay is 3 to 4 days and the main complications are bleeding and retrograde (dry) ejaculation. There are many variants to TURP, eg. TUIP, laser TURP, bipolar TURP but they are essentially different techniques/ using different machines. The Greenlight (PVP) laser has the advantage of less bleeding and shorter hospital stay. However, it is slower to perform and costs more than the standard TURP. Thermotherapy (heat treatment) is an alternative lesser-invasive option, eg. TUMT, TUNA but do not give an immediate channel, plus may not be durable. Open prostatectomy is reserved for huge BPH (eg. > 100 ml) but rarely done nowadays.

(a) Standard TURP
(b) Laser TURP

Fig 6. In TURP, a resectoscope (a) is used to cut away prostate tissue to recreate a channel. In laser TURP, the laser fibre (b) is used to vaporize prostate tissue