Upload
putri-dwi-kartini
View
221
Download
0
Embed Size (px)
Citation preview
8/13/2019 CHAPTER II BPH
1/30
8
CHAPTER II
LITERATURE
2.1 ANATOMY AND PHYSIOLOGY OF PROSTATE GLAND2.1.1 Anatomy Prostate Gland
The prostate is a fibromuscular and glandular organ lying just inferior
to the bladder. The normal prostate weighs about 25 g and contains the
posterior urethra, which is about 2.5 cm in length. It is supported anteriorly
by the puboprostatic ligaments and inferiorly by the urogenital diaphragm.
The prostate is perforated posteriorly by the ejaculatory ducts, which pass
obliquely to empty through the verumontanum on the floor of the prostatic
urethra just proximal to the striated external urinary sphincter.
According to the classification of Lowsley, the prostate consists of 5
lobes: anterior, posterior, median, right lateral, and left lateral. According to
McNeal (1972), the prostate has a peripheral zone, a centralzone, and a
transitional zone, an anterior segment, and a preprostatic sphincteric zone.
Fig 1. Anatomy of the prostate gland and surrounding structures.
Zonal model of the prostate
8/13/2019 CHAPTER II BPH
2/30
9
Fig 2. Anatomy of the prostate gland and surrounding structures. Fascial
planes around the prostate. A, artery; AFS, anterior fibromuscular stroma;
CZ, central zone; ED, ejaculatory duct; N, nerve; PZ, peripheral zone; TZ,
transition zone; U, urethra; V, vein.
The urethra that traverses the prostate gland is the prostatic urethra. It
is lined by an inner longitudinal layer of muscle (continuous with a similar
layer of the vesical wall). Incorporated within the prostate gland is an
abundant amount of smooth musculature derived primarily from the
external longitudinal bladder musculature. This musculature represents the
true smooth involuntary sphincter of the posterior urethra in males.
The prostate consists of a thin fibrous capsule under which are
circularly oriented smooth muscle fibers and collagenous tissue that
surrounds the urethra (involuntary sphincter). Deep in this layer lies the
prostatic stroma, composed of connective and elastic tissues and smooth
muscle fibers in which are embedded the epithelial glands. These glands
drain into the major excretory ducts (about 25 in number) which open
chiefly on the floor of the urethra between the verumontanum and the
vesical neck. Just beneath the transitional epithelium of the prostatic urethra
lie the periurethral glands.
8/13/2019 CHAPTER II BPH
3/30
10
The prostate gland receives arterial supply from the inferior vesical,
internal pudendal, and middle rectal (hemorrhoidal) arteries. The veins
from the prostate drain into the periprostatic plexus, which has connections
with the deep dorsal vein of the penis and the internal iliac (hypogastric)
veins. The prostate gland receives a rich nerve supply from the sympathetic
and parasympathetic nerve plexuses. The lymphatics from the prostate
drain into the internal iliac (hypogastric), sacral, vesical, and external iliac
lymph nodes.
2.1.2 Physiology Prostate GlandSecretions of the prostate gland is a milky fluid that together
secretions from the seminal vesicles are a major component of semen.
Semen contains citric acid so that a slightly acidic pH (6.5). Moreover, it
can be found fibrinolysin enzymes that act as a strong, acid phosphates,
other enzymes and lipids. Prostatic secretions released during ejaculation
through the contraction of smooth muscle.
2.2 BENIGN PROSTATE HYPERPLASIA2.2.1 Epidemiology
BPH is the most common benign tumor in men, and its incidence is age-
related. The prevalence of histologic BPH in autopsy studies rises from
approximately 20% in men aged 41-50, to 50% in men aged 51-60, and to
over 90% in men older than 80. Although clinical evidence of disease
occurs less commonly, symptoms of prostatic obstruction are also age-
related. At age 55, approximately 25% of men report obstructive voiding
symptoms. At age 75, 50% of men complain of a decrease in the force and
caliber of their urinary stream.
2.2.2 EtiologyThe etiology of BPH is not completely understood, but it seems to
be multifactorial and endocrine controlled. The prostate is composed of
8/13/2019 CHAPTER II BPH
4/30
11
both stromal and epithelial elements, and each, either alone or in
combination, can give rise to hyperplastic nodules and the symptoms
associated with BPH..
Some theories or hypotheses are suspected as the cause of prostatic
hyperplasia are:
1. Dihydrotestosterone
Testosterone is produced by the Leydig cells of the testis (90%) and a
portion of the adrenal gland (10%) in the blood circulation and 98% will
be bound by sex hormone binding globulin to globulin (SHBG). Being
only 2% in a state of free testosterone. Free testosterone is what can get
into the "target cell" that prostate cells directly through the cell
membrane into the cytoplasm, the cell, testosterone is reduced by the
enzyme 5-alpha reductase into 5-dihydrotestosterone were then met with
cytoplasmic receptors become "hormone receptor complex". Then
"hormone receptor complex" is undergoing transformation receptors, a
"nuclear receptor" that went into the core which is then attached to the
chromatin and lead to m-RNA transcription. RNA will cause protein
synthesis result in the growth of the prostate gland. This theory was
proven that the castration before puberty do not happen BPH, also the
regression of BPH when done castration.
2. Estrogen-testosterone imbalance
In addition to androgens (testosterone / DHT), estrogen also contributes
to the occurrence of BPH. With age will change the hormonal balance,
which is between testosterone and estrogen, as testosterone production
decreases and the conversion of testosterone to estrogen in peripheral
adipose tissue with the help of the enzyme aromatase, which is the
nature of estrogen will stimulate hyperplasia of the stroma, causing
notion that testosterone is necessary for the initiation of cell proliferation
but then estrogen which contribute to the development of the stroma.
Another possibility is that changes in the relative concentrations of
8/13/2019 CHAPTER II BPH
5/30
12
testosterone and estrogen will cause the production and potentiation of
other growth factors that can lead to an enlarged prostate.
From various experimental and clinical findings concluded that under
normal circumstances would cause the pituitary gonadotropin production
of testicular androgens that will control the growth of the prostate. With
increasing age, there will be a decrease of testicular function
(spermatogenesis), which will lead to a progressive decline of androgen
secretion. This result will greatly stimulate gonadothropin hormone
estrogen production by the Sertoli cells. While the views of the
functional histological, prostate consists of two parts, namely a central
around the urethra that reacts to estrogen and peripheral parts that do not
respond to estrogen.
3. Interaction stroma- epitel
This theory is based on the interaction between the elements of prostate
stromal and epithelial elements that cause prostate hyperplasia. The
growth factor was made by stromal cells under the influence of
androgens. The existence of over-expression of the epidermal growth
factor (EGF) and or fibroblast growth factor (FGF) and or a decrease in
the expression of transforming growth factor- (TGF-) will cause an
imbalance of prostate growth and produce an enlarged prostate.
4. Decrease in cell death
The aging process can lead to blockade the process of maturation in stem
cells, prevent them from entering the stage of programmed cell death
(apoptosis). As a result of the aging process in animal studies appears to
be mediated through the estrogen synergism induces androgen receptor,
steroi disrupt metabolism, resulting in increased levels of DHT in the
prostate that inhibit cell death when given in conjunction with androgen
nd poduksi stimulate collagen stroma.
5. Stem Cell Theory (stem cell hypothesis)
As in other organs, prostate gland periuretral in this case in an adult is in
a state of equilibrium "steady state", between cell growth and cell death,
8/13/2019 CHAPTER II BPH
6/30
13
the balance is due to the presence of certain levels of testosterone in the
prostate tissue that can affect the stem cells that can proliferate. In
certain circumstances the number of stem cells can be increased resulting
in more rapid proliferation. Abnormal stem cell proliferation leading to
the production or proliferation of stromal cells and epithelial cells
periuretral prostate gland becomes redundant.
2.2.3 PathophysiologyOne can relate the symptoms of BPH to either the obstructive
component of the prostate or the secondary response of the bladder to the
outlet resistance. The obstructive component can be subdivided into the
mechanical and the dynamic obstruction.
As prostatic enlargement occurs, mechanical obstruction may
result from intrusion into the urethral lumen or bladder neck, leading to a
higher bladder outlet resistance. Prior to the zonal classification of the
prostate, urologists often referred to the "3 lobes" of the prostate, namely,
the median and the two lateral lobes. Prostatic size on digital rectal
examination (DRE) correlates poorly with symptoms, in part because the
median lobe is not readily palpable.
The dynamic component of prostatic obstruction explains the
variable nature of the symptoms experienced by patients. The prostatic
stroma, composed of smooth muscle and collagen, is rich in adrenergic
nerve supply. The level of autonomic stimulation thus sets a tone to the
prostatic urethra. Use of alpha-blocker therapy decreases this tone,
resulting in a decrease in outlet resistance.
The irritative voiding complaints of BPH result from the
secondary response of the bladder to the increased outlet resistance.
Bladder outlet obstruction leads to detrusor muscle hypertrophy and
hyperplasia as well as collagen deposition. Although the latter is most
likely responsible for a decrease in bladder compliance, detrusor
instability is also a factor. On gross inspection, thickened detrusor muscle
8/13/2019 CHAPTER II BPH
7/30
14
bundles are seen as trabeculation on cystoscopic examination. If left
unchecked, mucosal herniation between detrusor muscle bundles ensues,
causing diverticula formation (so-called false diverticula composed of
only mucosa and serosa).
2.2.4 Clinical FindingsSymptoms
The symptoms of BPH can be divided into obstructive and
irritative complaints. Obstructive symptoms include hesitancy, decreased
force and caliber of stream, sensation of incomplete bladder emptying,
double voiding (urinating a second time within 2 hour of the previous
void), straining to urinate, and post-void dribbling. Irritative symptoms
include urgency, frequency, and nocturia.
The self-administered questionnaire developed by the American
Urological Association (AUA) is both valid and reliable in identifying the
need to treat patients and in monitoring their response to therapy. The
AUA Symptom Score questionnaire is perhaps the single most important
tool used in the evaluation of patients with BPH and is recommended for
all patients before the initiation of therapy.
8/13/2019 CHAPTER II BPH
8/30
15
Fig 4. The AUA Symptom Score questionnaire
This assessment focuses on 7 items that ask patients to quantify the
severity of their obstructive or irritative complaints on a scale of 0-5. Thus,
the score can range from 0 to 35. A symptom score of 0-7 is considered
mild, 8-19 is considered moderate, and 20-35 is considered severe.
Physical Examination
Digital Rectal Examination (DRE) is examination to determine the
size and consistency of the prostate is noted, even though prostate size.
BPH usually results in a smooth, firm, elastic enlargement of the prostate.
Induration, if detected, must alert the physician to the possibility of cancer
and the need for further evaluation.
8/13/2019 CHAPTER II BPH
9/30
16
On physical examination, when upper urinary tract abnormalities
occurs sometimes kidney may be palpable and when pyelonefritis happens
it will be accompanied by pain and percussion pain on the waist.
Gallbladder may be palpable urinary retention occur when it is total, the
inguinal area should begin to be considered to determine the hernia.
External genitalia should also be checked to see if there are other possible
causes that can lead to micturition disorders such as stones or urethral
fossa navicularis anterior, urethral fibrosis area, phimosis, condiloma
meatus area.
Laboratory Findings
A urinalysis to exclude infection or hematuria and serum creatinine
measurement to assess renal function are required. BSS to find possibility
of diabetes that can cause neurological gallbladder. Serum PSA is
considered optional, if suspicious of carcinoma prostate.
Imaging
a. Plain abdominal (BNO)
This examination use to look for the opaque stones in the urinary tract,
the presence of stones and sometimes may show a shadow of
gallbladder that filled with urine which is the sign of a urinary retention.
And also to know presence of bone metastases of prostate carcinoma.
b. Pyelography Intravenous (IVP)
Enlargement of the prostate can be seen as a filling defect / prostate
indentation at the base of the bladder or ureter distal end turned up
shaped like the eye of the hook (hooked fish). Can also be aware of any
abnormalities in the kidneys or ureters or hydronephrosis hidroureter
form and complications (trabeculation or diverticular). Photos after
micturition residual urine can be seen there.
c. Ultrasonography
8/13/2019 CHAPTER II BPH
10/30
17
Ultrasound can be either trans abdominal or trans rectal. Its use to find
an enlarged prostate, this examination can also determine abnormalities
in the bladder (mass, stone, blood clot), measuring residual urine and
kidney damage caused by prostatic obstruction. In TRUS prostate
malignancy likely hypoechoic area.
2.2.5 Differential DiagnosisOther obstructive conditions of the lower urinary tract, such as
urethral stricture, bladder neck contracture, bladder stone, or prostate
cancer must be entertained when evaluating men with presumptive BPH. A
history of previous urethral instrumentation, urethritis, or trauma should be
elucidated to exclude urethral stricture or bladder neck contracture.
Hematuria and pain are commonly associated with bladder stones. Prostate
cancer may be detected by abnormalities on the DRE or an elevated PSA.
A urinary tract infection, which can mimic the irritative symptoms
of BPH, can be readily identified by urinalysis and culture. However, a
urinary tract infection can also be a complication of BPH. Although
irritative voiding complaints are also associated with carcinoma of the
bladder, especially carcinoma in situ, the urinalysis usually shows evidence
of hematuria. Likewise, patients with neurogenic bladder disorders may
have many of the signs and symptoms of BPH, but a history of neurologic
disease, stroke, diabetes mellitus, or back injury may be present as well. In
addition, examination may show diminished perineal or lower extremity
sensation or alterations in rectal sphincter tone or the bulbocavernosus
reflex. Simultaneous alterations in bowel function (constipation) might also
alert one to the possibility of a neurologic origin.
2.2.6 TreatmentAfter patients have been evaluated, they should be informed of the
various therapeutic options for BPH. Specific treatment recommendations
can be offered for certain groups of patients. For those with mild symptoms
8/13/2019 CHAPTER II BPH
11/30
18
(symptom score 0-7), watchful waiting only is advised. On the other end of
the therapeutic spectrum, absolute surgical indications include refractory
urinary retention (failing at least one attempt at catheter removal), recurrent
urinary tract infection from BPH, recurrent gross hematuria from BPH,
bladder stones from BPH, renal insufficiency from BPH, or large bladder
diverticula (McConnell et al, 1994).
A. Watchful Waiting
As mentioned above, watchful waiting is the appropriate management of
men with mild symptom scores (0-7). Men with moderate or severe
symptoms can also be managed in this fashion if they so choose. Neither
the optimal interval for follow-up nor specific endpoints for intervention
have been defined.
B. Medical Therapy
1. Alpha blockers
The human prostate and bladder base contains alpha-1-
adrenoreceptors, and the prostate shows a contractile response to
corresponding agonists. The contractile properties of the prostate and
bladder neck seem to be mediated primarily by the subtype a1a
receptors. Alpha blockade has been shown to result in both objective and
subjective degrees of improvement in the symptoms and signs of BPH in
some patients. Examples of alpha inhibition include prazosin, terazosin,
doxazosin and newer tamslosin (selective blockade of receptors 1a).
Side effects include hypotension APHA inhibitors ortostatik, dizziness,
fatigue, retrograde ejaculation, rhinitis and headache. This side effect is
less on the use of a more selective inhibition 1a.
2. 5a-Reductase inhibitors
This drug is a 5a-reductase inhibitor that blocks the conversion of
testosterone to dihydrotestosterone. This drug affects the epithelial
8/13/2019 CHAPTER II BPH
12/30
19
component of the prostate, resulting in a reduction in the size of the
gland and improvement in symptoms. Six months of therapy are required
to see the maximum effects on prostate size (28% reduction) and
symptomatic improvement. Side effects include decreased libido,
decreased ejaculate volume and impotence.
3. Phytotherapy
Phytotherapy refers to the use of plants or plant extracts for medicinal
purposes. The use of phytotherapy in BPH has been popular in Europe
for years, and its use in the United States is growing as a result of
patient-driven enthusiasm. Several plant extracts have been popularized,
including the saw palmetto berry, the bark of Pygeum africanum, the
roots of Echinacea purpurea and Hypoxis rooperi, pollen extract, and the
leaves of the trembling poplar. The mechanisms of action of these
phytotherapies are unknown, and the efficacy and safety of these agents
have not been tested in multicenter, randomized, double-blind, placebo-
controlled studies.
C. Conventional Surgical Therapy
1. Transurethral Resection of The Prostate (TURP)
Ninety-five percent of simple prostatectomies can be done
endoscopically. Most of these procedures involve the use of a spinal
anesthetic and require 1 to 2 day hospital stay. Risks of TURP include
retrograde ejaculation (75%), impotence (5-10%), and incontinence (