The prostate gland is a solid organ which measures about 3.5 by 2.5cm and 18-26g in weight. It is shaped like a chestnut or compressed inverted cone, with its base upwards and apex downwards within the male perineum. It surrounds the prostatic urethra which pierces it on its way to the penis. The prostate gland is seen only in men and thus, disease of the prostate gland is seen exclusively in men.
After the age of 40 years, the prostate gland increases in size due to the excessive proliferation of the cells of the gland. When the prostate gland enlarges, it compresses the urethra which passes through it from the bladder leading to a cascade of symptoms that depends on the size of the gland and the degree of urethral compression. The hallmark of prostate enlargement is urinary retention. The hyperplasia of the cellular components of the prostate gland is referred to as benign prostatic hyperplasia (BPH).
Causes of benign prostatic hyperplasia
The etiological factors of BPH are complex and there include ageing, the presence of functioning testes and normal androgen levels. It is not seen in men who are less than 20-year olds and in men castrated before puberty or with 5-alpha reductase deficiency. Other risk factors are positive familial and genetic factors, increase in 5- alpha reductase activity, estrogen imbalance and increased response of the epithelial cells of the prostate glands to hormones leading to hyperplasia.
Symptoms of benign prostatic enlargement
The symptoms of prostate enlargement are divided into irritative and obstructive symptoms.
The early presentation of BPH is usually sudden and may not be noticed by the patients. They are recognized early by a Yes answer to any of these 3 questions:
- Do you get up at night to pass urine?
- Is your urine flow slow?
- Are you bothered by your bladder function?
With further narrowing of the urethra, patients begin to experience the classical symptoms of prostate enlargement.
Irritative symptoms: caused by the initial irritation of the bladder from prostate enlargement. At this stage, conditions like urinary tract infection (UTI), carcinoma of the prostate or bladder, chronic prostatitis, neurogenic bladder, diabetes mellitus may mimic prostate enlargement.
- Increase frequency of urination: this is said to occur when there is a clear and noticeable increase in the number of times and individual urinates in a day. It is important to take into consideration environmental changes and increase water intake as there can affect frequency hence giving a false positive symptom of prostate enlargement
- Nocturia: this is the noticeable increase in the number of times an individual urinates at night
- Urgency: an uncomfortable, uncontrollable and irresistible urge to urinate
- Urge incontinence: an inappropriate dribbling of urine from the bladder after a short duration of bladder fullness.
Obstructive symptoms: obstructive symptoms of prostate enlargement results from the compression of the urethra as it pass through the prostate gland. This reduces the caliber of the urethra. When the compression is complete, urinary retention occurs.
Obstructive symptoms include:
- Delaying in initiating urination lasting for few minutes. This responds correlates to the degree of urethra narrowing. It is referred to as ‘hesistency’ by physicians.
- Straining to achieve urination and to maintain urine stream.
- Poor stream: this is the reduction in the flow of the stream of urine from the urethra caused by the narrowing of the urethra. At this point, most patients are now aware of a dysfunction in their system. Urine stream initially improves with straining but in advance cases, urinary stream is poor despite straining
- Terminal dribbling: dribbling of urine after urination is abnormal and it indicates prostate enlargement.
- Feeling of residual urine in the bladder after micturition.
- Passage of bloody urine
- Urinary retention
- Prolonged micturition
The assessment of prostate symptoms can be carried out with the use of International Prostate Symptoms Score (IPSS) which is a structured symptoms questionnaire which was developed by the American Urological Association and was adopted by the WHO in 1994. It is simple and has been tested and retested for reliability. It allows the physician to quickly assess the presence of each symptom and also the severity and the impact of the symptoms on the quality of life of the patient.
Using the IPSS, each symptom (7 symptoms are assessed using this scoring technique) is scored from 0-5 with a maximum score of 35. The interpretation of IPSS score values are:
- Mild 0-8
- Moderate 9-19
- Severe 20-35
Digital rectal examination (DRE) is an important component in the evaluation of men with prostate enlargement. It helps the physician to assess the size of the prostate gland, consistency and the presence of nodules. This differentiates benign prostatic hyperplasia from prostate cancer. In BPH, the gland is enlarged, firm, with a smooth surface and the median sulcus is preserved.
Treatment of prostate enlargement
- Drugs: drugs have been used to control the severity of the symptoms caused by prostate enlargement. These drugs act by inhibiting the growth of the gland of by reducing the rate of contraction of the smooth muscle components of the gland. Commonly used drugs include: anticholinergic agents, adrenergic receptor blockers and 5-alpha reductase inhibitors
- Minimally invasive procedures: these are procedures used in the treatment of moderately enlarged prostate glands. There are safe procedures, with excellent cure rate and the outcome is generally good
- Transurethral incision of the prostate
- Laser incision of the prostate gland
- Transurethral needle ablation (TUNA)
- Use of prostatic stents to dilate the narrowed part of the urethra
- Use of high intensity ultrasound energy waves
- Laparoscopic prostatectomy
- Open prostatectomy
- Transurethral resection of the prostate
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