Drug Treatments
Over the years, researchers have tried to
find a way to shrink or at least stop the growth of the
prostate without using surgery. The Food and Drug
Administration (FDA) has approved four drugs to relieve
common symptoms associated with an enlarged prostate.
Finasteride, FDA-approved in 1992
(marketed under the name Proscar), and dutasteride,
FDA-approved in 2001 (marketed as Avodart), inhibit
production of the hormone DHT, which is involved with
prostate enlargement. The use of either of these drugs
can either prevent progression of growth of the prostate
or actually shrink the prostate in some men.
FDA also approved the drugs terazosin
(marketed as Hytrin) in 1993, doxazosin (marketed as
Cardura) in 1995, tamsulosin (marketed as Flomax) in
1997, and alfuzosin (marketed as Uroxatral) in 2003 for
the treatment of BPH. All four drugs act by relaxing the
smooth muscle of the prostate and bladder neck to
improve urine flow and to reduce bladder outlet
obstruction. The four drugs belong to the class known as
alpha blockers. Terazosin and doxazosin were developed
first to treat high blood pressure. Tamsulosin and
alfuzosin were developed specifically to treat BPH.
NIDDK's Medical Therapy of Prostatic
Symptoms (MTOPS) Trial recently found that using
finasteride and doxazosin together is more effective
than either drug alone to relieve symptoms and prevent
BPH progression. The two-drug regimen reduced the risk
of BPH progression by 67 percent, compared to 39 percent
for doxazosin alone and 34 percent for finasteride
alone.
Minimally Invasive Therapy
Because drug treatment is not effective
in all cases, researchers in recent years have developed
a number of procedures that relieve BPH symptoms but are
less invasive than conventional surgery.
Transurethral microwave procedures.
In May 1996, FDA approved the Prostatron, a device that
uses microwaves to heat and destroy excess prostate
tissue. In the procedure called transurethral microwave
thermotherapy (TUMT), the Prostatron sends
computer-regulated 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.
A similar microwave device, the Targis
System, received FDA approval in September 1997. Like
the Prostatron, the Targis System delivers microwaves to
destroy selected portions of the prostate and uses a
cooling system to protect the urethra. A heat-sensing
device inserted in the rectum helps monitor the therapy.
Both procedures take about 1 hour and can
be performed on an outpatient basis without general
anesthesia. Neither procedure has been reported to lead
to impotence 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. Ongoing research
will determine any long-term effects of microwave
therapy and who might benefit most from this therapy.
Transurethral needle ablation.
In October 1996, FDA approved Vidamed's minimally
invasive Transurethral Needle Ablation (TUNA) System for
the treatment of BPH.
The TUNA System delivers low-level
radiofrequency energy through twin needles to burn away
a well-defined region 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 transurethral resection
of the prostate (TURP). No incontinence or impotence has
been observed.
Surgical Treatment
Most doctors recommend removal of the
enlarged part of the prostate as the best long-term
solution for patients with BPH. With surgery for BPH,
only the enlarged tissue that is pressing against the
urethra is removed; the rest of the inside tissue and
the outside capsule are left intact. Surgery usually
relieves the obstruction and incomplete emptying caused
by BPH. The following section describes the types of
surgery that are used.
Transurethral surgery.
In this type of surgery, no external incision is needed.
After giving anesthesia, the surgeon reaches the
prostate by inserting an instrument through the urethra.
A procedure called TURP (transurethral
resection of the prostate) is used for 90 percent of all
prostate surgeries done for BPH. With TURP, an
instrument called a resectoscope is inserted through the
penis. The resectoscope, which is about 12 inches long
and 1/2 inch in diameter, contains a light, valves for
controlling irrigating fluid, and an electrical loop
that cuts tissue and seals blood vessels.
During the 90-minute operation, the
surgeon uses the resectoscope's wire loop to remove the
obstructing tissue one piece at a time. The pieces of
tissue are carried by the fluid into the bladder and
then flushed out at the end of the operation.
Most doctors suggest using TURP whenever
possible. Transurethral procedures are less traumatic
than open forms of surgery and require a shorter
recovery period.
Another surgical procedure is called
transurethral incision of the prostate (TUIP). Instead
of removing tissue, as with TURP, this procedure widens
the urethra by making a few small cuts in the bladder
neck, where the urethra joins the bladder, and in the
prostate gland itself. Although some people believe that
TUIP gives the same relief as TURP with less risk of
side effects such as retrograde ejaculation, its
advantages and long-term side effects have not been
clearly established.
Open
surgery.
In the few cases when a transurethral procedure cannot
be used, open surgery, which requires an external
incision, may be used. Open surgery is often done when
the gland is greatly enlarged, when there are
complicating factors, or when the bladder has been
damaged and needs to be repaired. The location of the
enlargement within the gland and the patient's general
health help the surgeon decide which of the three open
procedures to use.
With all the open procedures, anesthesia
is given and an incision is made. Once the surgeon
reaches the prostate capsule, he scoops out the enlarged
tissue from inside the gland.
Laser
surgery.
In March 1996, FDA approved a surgical procedure that
employs side-firing laser fibers and Nd: YAG lasers to
vaporize obstructing prostate tissue. The doctor passes
the laser fiber through the urethra into the prostate
using a cystoscope and then delivers several bursts of
energy lasting 30 to 60 seconds. The laser energy
destroys prostate tissue and causes shrinkage. Like
TURP, laser surgery requires anesthesia and a hospital
stay. One advantage of laser surgery over TURP is that
laser surgery causes little blood loss. Laser surgery
also allows for a quicker recovery time. But laser
surgery may not be effective on larger prostates. The
long-term effectiveness of laser surgery is not known.
