Benign Prostatic Hyperplasia

Introduction

Obstruction of urine flow by an enlarged prostate gland is a common condition. Almost 50% of the male population above age 50 will have some clinical evidence of prostate enlargement.

TURP (prostate operation to relieve obstruction) procedures are one of the most commonly performed operations in men over the age of 70.

Surgery to relieve the prostatic enlargment  has been described since the early 19th century, but the development of fibreoptic telescopes and videocamera imaging has greatly enhanced the success rate of TURP.

Anatomy & Physiology

  •  The prostate gland is shaped like an inverted pear and lies just below the neck of the urinary bladder. It is about 5 cm (3 inches) long and 3-4cm wide. The urethra, which runs from the bladder through the middle of the prostate gland and through the penis, carries urine from the bladder.
  •  The smooth muscle of the urethra is the internal urinary sphincter.
    Just below the prostate gland is a muscular diaphragm that acts as the external urinary sphincter. This sphincter, which encircles the urethra, is under both reflex and voluntary control.
  •  Along the back wall of the urethra in the prostate, there is an elevation called the verumontanum, and it is into this elevation that sperm (through the ejaculatory ducts) and spermatic secretions from the seminal vesicles and prostate enter the urethra.

Anatomy Prostate

Pathology

  •  Benign Prostatic Hyperplasia (BPH) is a condition caused by an excessive growth of prostate tissue around the urethra. The prostate growth is influenced by the male hormone, testosterone. Prostate growth increases with age.
  •  With the increased size of the prostate, the urethra is compressed causing decreased urinary flow and incomplete emptying of the bladder. The high pressure required to empty the bladder gives rise to an increased risk of urinary infection and bladder stones. Inflammation of the bladder and urethra may also cause blood in the urine.
  •  Because of the increased pressure on the bladder wall muscles, the wall may become hypersensitive. This gives rise to the symptoms of urgency (feeling to urinate) and nocturia (the need to urinate at night).
  •  Backpressure from the bladder may affect the kidneys causing the kidneys to swell (hydronephrosis) with eventual kidney failure.


History and Examination

  •  A patient with an enlarged prostate complains of symptoms that are related to obstruction of urine flow, irritation and symptoms that occur later.
  •  Obstructive symptoms: -

1. Hesitancy or delay in urine flow during attempted urination. There is a decrease in force and size of the urinary stream. There may be intermittency (pauses in flow of stream), dribbling of urine at the end of urination and a feeling of incomplete emptying of the bladder.

2. Irritative symptoms include increased frequency and urgency of urination; nocturia; pain on urination from bladder stones; infection or muscle spasms and blood in the urine from infection, inflammation or bleeding veins at the surface of the prostate.

3. Delayed symptoms are those of renal failure due to kidney involvement and the development of a hernia or haemorrhoids from constant straining during urination.

  •  During the physical examination, the prostate gland is examined. Digital rectal exam (DRE) is carried out by inserting a finger into the rectum. The prostate gland lies just in front of the rectum and can be felt for size and nodules. It is important to rule out a cancer of the prostate.


Diagnostic Testing

  •  Urine analysis looks for blood and bacteria.
  •  Blood tests may include electrolytes (concentration of salt in the blood), serum urea nitrogen and creatinine as a baseline of kidney function.
  •  A Prostate Specific Antigen (PSA). The PSA level may be slightly raised with BPH due to increased size of the gland, but any increase suggests prostate cancer.
  •  Uroflowmetry (measurement of urine flow) is one of the simplest and most diagnostic tests for bladder outlet obstruction. Normal individuals usually have urine flow rates between 12 - 20 cc/sec. Flow rates of less than 10 cc/sec are seen with bladder outlet obstruction.
  •  The residual volume (volume remaining) after urinating can be measured either by catherization (catheter placed in the bladder) or ultrasound
    (using sound waves). Residual volumes greater than 100 - 15O cc are usually indicative of significant prostate obstruction.
  •  Ultrasound does not require the placement of a catheter or other instrument in the bladder. Sound waves are bounced off the bladder back to a receiving unit that converts the waves into a picture. This test can detect urinary volume, stones in the bladder and evidence of back pressure on the kidneys. It can also measure the size and volume of the prostate and help in decision making on appropriate treatment.
  • Uroflowmetry is the measurement of the rate of urinary flow per second and is an important investigation to determine the presence of bladder outlet obstruction. This is combined with an ultrasonic assessment of the amount of urine left in the bladder after the completion. This is  performed by the urology nurses in the Urology Associates suite at Cabrini Hospital.

 

Treatment

Medical Treatment

  •  Medical therapy is appropriate for patients who have mild symptoms of urinary obstruction or are too old or unwell to undergo a surgical procedure.
  •  Relief from obstruction may not be immediate and usually necessitates life long medical treatment. Medical treatment may be ineffective with high grade obstruction.
  •  There are two main drug groups that are used to treat BPH: -

1. Muscle Relaxants - This group of drugs blocks nerve impulses going to the muscles of the involuntary internal sphincter thus easing urinary flow. Side affects of these medications include low blood pressure, dizziness, fast heart rate, tiredness, nasal congestion and retrograde ejaculation (sperm goes into the bladder).

2. Hormonal Agents - These drugs attempt to reverse the effect of testosterone on the prostate causing a decrease in size. This is accomplished by blocking the effect of testosterone on the prostate. Side effects of these drugs may include impotence and a loss of libido.

 

Surgical Therapy

Transurethral Resection of the Prostate (TURP)

Indications for Surgery

  •  Surgery is usually indicated for obstructive or irritative symptoms of BPH that may not be relieved by medical management.
  •  A significant decrease in urine flow rate (<10 cc/sec) or significant residual volumes (>100 - 150 cc).
  • Acute or sudden  urinary retention
  • BPH is a disease that is progressive. Surgery is advised before complications arise.
 TURP

 

Surgical Procedure

  •  The procedure usually takes less than an hour to perform and is usually performed under spinal or general anaesthesia.
  •  The patient is placed in the lithotomy position (with the legs elevated and spread).
  •  The bladder is filled with a special solution that does not conduct electricity.
  •  A cystoscope, which is a special telescope, is inserted into the penis and passes up the urethra, until it reaches the prostatic portion of the urethra.
  • A special wire loop, called the resectoscope, is then inserted into the urethra. The resectoscope has electrical current passing through the loop that acts to cut the prostate tissue. The resectoscope shaves off "chips" of the enlarged prostate gland. The shaving starts at the margin of the bladder outlet and progresses into the prostatic part of the urethra up to the verumontanum and possibly beyond thus the removed portion includes some of the involuntary internal sphincter.
  •  The ejaculatory ducts that open on the verumontanum and carry spermatic secretions are preserved. The voluntary external sphincter lies below the verumontanum. This sphincter will also be preserved, to allow control of urination.
  •  At the end of the procedure, the bladder outlet remains open and unobstructed. The bladder is irrigated to flush out any blood clots and prostatic chips.
  •  A catheter is left in place to drain the bladder.

 GYRUS TURP  is a  newer technique currently being used by Urology Associates.  This  involves bipolar diathermy resection of the prostate which has the potential advantages of 1. allowing the use of  normal saline irrigation fluid which is safer than the glycine irrigation used with standard TURP. 2. there is less bleeding and 3.it allows vaporisation of  the prostatic chips while shaving thus leaving less tissue debris at the end of the procedure. 

Urology associates now routinely use this technique for prostate removal.

Complications

Complications seen with TURP and their approximate rates of occurrence are: -

  •  Bleeding (<5%).
  •  Infection (<2%).
  •  Perforation of the bladder (<1 %).
  •  Inability to pass urine -usually due to muscle dysfunction with longstanding BPH (5%).
  •  Stricture of the urethra from scarring (2.5%).
  •  Urinary incontinence from damage to the sphincter (<2%).
  •  Impotence (5% dependent on patient age)
  •  Retrograde ejaculation (passage of sperm) (50%) - because of the loss of the internal sphincter, spermatic secretions may go upwards into the bladder rather than down through the penis during ejaculation. These secretions will pass out later during urination. This may give rise to sterility due to reduced sperm count.
  •  TUR Syndrome (<2%) - Extensive TURP, especially with very large prostates, may open up venous blood vessels during surgery. Fluid in the bladder may get absorbed into the blood causing fluid overload and electrolyte (salt) imbalance in the body. Fluid overload may be particularly a problem in a patient with heart or lung disease. Electrolyte imbalance may cause neurologic symptoms, including seizures and coma. This syndrome is now preventable with the use of the new bipolar resectoscope. (GYRUS TURP).

Postoperative Care

  • Blood tinged urine may be present at the end of the procedure. Frankly bloody urine with clots may require irrigation of the bladder through the catheter.
  • The catheter is kept in until the urine clears, which is usually 24 - 48 hours. Patients usually stay in the hospital during this time.
  • Patients do not usually experience much pain after the operation and can usually shortly return to work.
  • Antibiotics are usually given for a several days to a few weeks after the operation to prevent infection.
  • About 8% of patients will require a repeat TURP or opening of a scar or stricture (narrowing) during the remainder of their lives.

Alternative Therapies

  •  Transurethral Incision of the Prostate (TUIP) - This technique involves making incisions from the bladder down to the veru montanum in the prostate. These incisions cut through the involuntary internal sphincter and open the urinary tract. Results of this technique are almost as good as TURP and there is less chance of complications. This technique may be used for smaller prostates and in younger patients.
  • Greenlight  Laser Ablation - This technique is newer and involves use of a probe which fires a laser to evaporate prostatic tissue. There is less bleeding in this procedure and may be beneficial in-patients with bleeding disorders. Long-term results of this technique   are reasonable but large glands do not do as well.
  •  Open Prostatectomy - An open procedure may be advisable in-patients with extremely large prostates as the risk of complications from TURP increases with increasing size of the prostate. This procedure may also be necessary if additional procedures are needed (e.g. removal of a bladder stone). An incision is made in the lower abdomen and the prostate is "shelled" out of it's capsule. Although the risk of many of the complications or TURP is reduced, recovery time is longer.
  •  Balloon Dilation/Stenting - These techniques have not demonstrated good long term results but are considered in patients too sick to undergo a formal surgical procedure.
  •  TUMT - TransUrethral Microwave Therapy may be successful but is not as well controlled as laser or TURP.