prostatic hyperplasia

前立腺肥大症

WordNet

1. abnormal increase in number of cells

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/10/06 09:57:58」(JST)

wiki en

[Wiki en表示]

Benign prostatic hyperplasia
Diagram illustrating normal prostate (left) and benign prostatic hyperplasia (right).
Classification and external resources
Specialty	Urology
ICD-10	N40
ICD-9-CM	600
DiseasesDB	10797
MedlinePlus	000381
eMedicine	med/1919
Patient UK	Benign prostatic hyperplasia
MeSH	D011470

Benign prostatic hyperplasia (BPH), also called benign enlargement of the prostate (BEP or BPE), adenofibromyomatous hyperplasia and benign prostatic hypertrophy (technically incorrect usage), is a benign increase in size of the prostate.

BPH involves hyperplasia of prostatic stromal and epithelial cells, resulting in the formation of large, fairly discrete nodules in the transition zone of the prostate. When sufficiently large, the nodules impinge on the urethra and increase resistance to flow of urine from the bladder. This is commonly referred to as "obstruction," although the urethral lumen is no less patent, only compressed. Resistance to urine flow requires the bladder to work harder during voiding, possibly leading to progressive hypertrophy, instability, or weakness (atony) of the bladder muscle. Although prostate specific antigen levels may be elevated in these patients because of increased organ volume and inflammation due to urinary tract infections, BPH does not lead to cancer or increase the risk of cancer.

BPH involves hyperplasia (an increase in the number of cells) rather than hypertrophy (a growth in the size of individual cells), but the two terms are often used interchangeably, even amongst urologists.

Adenomatous prostatic growth is believed to begin at approximately age 30 years. An estimated 50% of men have histologic evidence of BPH by age 50 years and 75% by age 80 years; in 40–50% of these men, BPH becomes clinically significant. BPH was one of the ten most prominent and costly diseases in men older than 50 years of age in a study in the United States.

Signs and symptoms

Benign prostatic hyperplasia symptoms are classified as storage or voiding.

Lower urinary tract symptoms

Voiding symptoms

• Hesitancy
• Poor flow
• Intermittent stream
• Dribbling
• Sensation of poor bladder emptying
• Episodes of near retention

Storage symptoms

• Frequency
• Nocturia
• Urge incontinence
• Nocturnal incontinence
• Urgency

Complications of bladder outlet obstruction

Acute retention

• Inability to pass urine
• Supra-pubic, constant, dull aching pain

Chronic retention

• Overflow incontinence, hernia, hemorrhoids
• Symptoms related to cause of retention

Features of uremia

• Headache
• Fits, drowsiness

Storage symptoms include urinary frequency, urgency (compelling need to void that cannot be deferred), urgency incontinence, and voiding at night (nocturia). Urinary incontinence may occur, and nocturia may contribute to insomnia.

Voiding symptoms include urinary hesitancy (difficulty initiating the stream), straining to void, weak or intermittent stream (starts and stops), and incomplete bladder emptying. Pain and dysuria are usually not present. These storage and voiding symptoms are evaluated using the International Prostate Symptom Score (IPSS) questionnaire, designed to assess the severity of BPH.

BPH can be a progressive disease, especially if left untreated. Incomplete voiding results in stasis of bacteria in the bladder residue and an increased risk of urinary tract infection. Urinary bladder stones are formed from the crystallization of salts in the residual urine. Urinary retention, termed acute or chronic, is another form of progression. Acute urinary retention is the inability to void, while in chronic urinary retention the residual urinary volume gradually increases, and the bladder distends. This can result in bladder hypotonia. Some patients who suffer from chronic urinary retention may eventually progress to renal failure, a condition termed obstructive uropathy.

Causes

Most experts consider androgens (testosterone and related hormones) to play a permissive role in the development of BPH. This means that androgens have to be present for BPH to occur, but do not necessarily directly cause the condition. This is supported by evidence suggesting that castrated boys do not develop BPH when they age. In an unusual study of 26 eunuchs from the palace of the Qing dynasty still living in Beijing in 1960, the prostate was impalpable (could not be felt) in 81%. The average time since castration was 54 years (range, 41–65 years). On the other hand, some studies suggest that administering exogenous testosterone is not associated with a significant increase in the risk of BPH symptoms, so the role of testosterone in prostate cancer and BPH is still unclear. Further randomized controlled trials with more participants are needed to quantify any risk of giving exogenous testosterone. Dihydrotestosterone (DHT), a metabolite of testosterone, is a critical mediator of prostatic growth. DHT is synthesized in the prostate from circulating testosterone by the action of the enzyme 5α-reductase, type 2. This enzyme is localized principally in the stromal cells; hence, those cells are the main site for the synthesis of DHT.

DHT can act in an autocrine fashion on the stromal cells or in paracrine fashion by diffusing into nearby epithelial cells. In both of these cell types, DHT binds to nuclear androgen receptors and signals the transcription of growth factors that are mitogenic to the epithelial and stromal cells. DHT is 10 times more potent than testosterone because it dissociates from the androgen receptor more slowly. The importance of DHT in causing nodular hyperplasia is supported by clinical observations in which an inhibitor of 5α-reductase such as finasteride is given to men with this condition. Therapy with a 5α-reductase inhibitor markedly reduces the DHT content of the prostate and, in turn, reduces prostate volume and BPH symptoms.

Testosterone promotes prostate cell proliferation, but relatively low levels of serum testosterone are found in patients with BPH. One small study has shown that medical castration lowers the serum and prostate hormone levels unevenly, having less effect on testosterone and dihydrotestosterone levels in the prostate.

While there is some evidence that estrogen may play a role in the etiology of BPH, this effect appears to be mediated mainly through local conversion of androgens to estrogen in the prostate tissue rather than a direct effect of estrogen itself. In canine in vivo studies castration, which significantly reduced androgen levels but left estrogen levels unchanged, caused significant atrophy of the prostate. Studies looking for a correlation between prostatic hyperplasia and serum estrogen levels in humans have generally shown none.

In 2008, Gat et al. published evidence that BPH is caused by failure in the spermatic venous drainage system resulting in increased hydrostatic pressure and local testosterone levels elevated more than 100 fold above serum levels. If confirmed, this mechanism explains why serum androgen levels do not seem to correlate with BPH and why giving exogenous testosterone would not make much difference. This also has implications for treatment (see Minimally invasive therapies below).

Studies indicate that dietary patterns may affect development of BPH, but further research is needed to clarify any important relationship. Studies from China suggest that greater protein intake may be a factor in development of BPH. Men older than 60 years in rural areas had very low rates of clinical BPH, while men living in cities and consuming more animal protein had a higher incidence of BPH. On the other hand, a study in Japanese-American men found a strong association with alcohol intake, but a weak association with beef intake. In a large prospective cohort study in the US (the Health Professionals Follow-up Study), investigators reported modest associations between BPH (men with strong symptoms of BPH or surgically confirmed BPH) and total energy and protein, but not fat intake. There is also epidemiological evidence linking BPH with metabolic syndrome (concurrent obesity, impaired glucose metabolism and diabetes, hypertriglyceridemia, low-density cholesterol and hypertension).

Benign prostatic hyperplasia is an age-related disease. Misrepair-accumulation aging theory suggests that development of benign prostatic hyperplasia is a consequence of fibrosis and weakening of the muscular tissue in the prostate. The muscular tissue is important in the functionality of the prostate, and provides the force for excreting the fluid produced by prostatic glands. However, repeated contractions and dilations of myofibers will unavoidably cause injuries and broken myofibers. Myofibers have low potential of regeneration; therefore collagen fibers need to be used to replace the broken myofibers. Such misrepairs make the muscular tissue weak in functioning, and the fluid secreted in glands cannot be excreted completely. Then, the accumulation of fluid in glands increases the resistance of muscular tissue during the movements of contractions and dilations, and more and more myofibers will be broken and replaced by collagen fibers. Progressive fibrosis of muscular tissue and accumulation of fluid are important causes for the expanding of the prostate in benign prostatic hyperplasia.

Pathophysiology

Benign prostate hyperplasia

Both the glandular epithelial cells and the stromal cells (including muscular fibers) undergo hyperplasia in BPH.^:694 Most sources agree that of the two tissues, stromal hyperplasia predominates, but the exact ratio of the two is unclear.^:694

Anatomically the median lobe is usually enlarged in BPH. The anterior lobe has little in the way of glandular tissue and is seldom enlarged. (Carcinoma of the prostate typically occurs in the posterior lobe – hence the ability to discern an irregular outline per rectal examination). The earliest microscopic signs of BPH usually begin between the age of 30 and 50 years old in the PUG, which are posterior to the proximal urethra.^:694 In BPH, the majority of growth occurs in the TZ.^:694 In addition to these two classic areas, the peripheral zone (PZ) of the prostate is also involved to a lesser extent.^:695 Prostatic cancer typically occurs in the PZ. However, BPH nodules, usually from the TZ are often biopsied anyway to rule out cancer in the TZ.^:695 However, cancers of the prostate most frequently occur in the PZ rather than the TZ, thus, chippings taken from the PZ are of limited use.

Diagnosis

Urinary bladder (black butterfly-like shape) and hyperplastic prostate (BPH) visualized by sonography

Micrograph showing nodular hyperplasia (left off center) of the prostate from a transurethral resection of the prostate (TURP). H&E stain.

Microscopic examination of different types of prostate tissues (stained with immunohistochemical techniques): A. Normal (non-neoplastic) prostatic tissue (NNT). B. Benign prostatic hyperplasia. C. High-grade prostatic intraepithelial neoplasia (PIN). D. Prostatic adenocarcinoma (PCA).

Prostate with a large median lobe bulging upwards. A metal instrument is placed in the urethra (which passes through the prostate). This specimen was almost 7 centimeters long with a volume of about 60 cubic centimetres on transrectal ultrasound and was removed during a Hryntschak procedure or transvesical prostatectomy (removal of the prostate through the bladder) for benign prostatic hyperplasia.

Rectal examination (palpation of the prostate through the rectum) may reveal a markedly enlarged prostate, usually affecting the middle lobe.

Blood tests are often performed to rule out prostatic malignancy. Elevated prostate specific antigen (PSA) levels need further evaluation, such as reinterpretation of PSA results, in terms of PSA density and PSA free percentage, rectal examination and transrectal ultrasonography. These combined measures can provide early detection.

Ultrasound examination of the testicles, prostate, and kidneys is often performed, again to rule out malignancy and hydronephrosis.

Screening and diagnostic procedures for BPH are similar to those used for prostate cancer. Some signs to look for include:

• Weak urinary stream
• Prolonged emptying of the bladder
• Abdominal straining
• Hesitancy
• Irregular need to urinate
• Incomplete bladder emptying
• Post-urination dribble
• Irritation during urination
• Frequent urination
• Nocturia (need to urinate during the night)
• Urgency
• Incontinence (involuntary leakage of urine)
• Bladder pain
• Dysuria (painful urination)
• Problems in ejaculation

Management

Lifestyle

Lifestyle alterations to address the symptoms of BPH include decreasing fluid intake before bedtime, moderating the consumption of alcohol and caffeine-containing products, and following a timed voiding schedule. Patients can also attempt to avoid products and medications that may exacerbate symptoms of BPH, including antihistamines, diuretics, and decongestants, opiates, and tricyclic antidepressant; however, changes in medications should be done with input from a medical professional.

Voiding position

Voiding position when urinating may influence urodynamic parameters (urinary flow rate, voiding time, and post-void residual volume). A meta-analysis found no differences between the standing and sitting positions for healthy males, but that, for elderly males with lower urinary tract symptoms (LUTS), voiding in the sitting position:

• the post void residual volume (PVR, ml) was significantly decreased
• the maximum urinary flow (Qmax, ml/s) was increased, comparable with pharmacological intervention
• the voiding time (VT, s) was decreased

This urodynamic profile is associated with a lower risk of urologic complications, such as cystitis and bladder stones.

Medications

The two main medications for management of BPH are alpha blockers and 5α-reductase inhibitors.

Alpha blockers are the most common choice for initial therapy. They include doxazosin, terazosin, alfuzosin, tamsulosin, and silodosin. They have a small to moderate benefit. All five are equally effective but have slightly different side effect profiles. The older drugs phenoxybenzamine and prazosin are not recommended. Alpha blockers relax smooth muscle in the prostate and the bladder neck, thus decreasing the blockage of urine flow. Common side effects of alpha blockers include orthostatic hypotension, (a head rush or dizzy spell when standing up or stretching), ejaculation changes, headaches, nasal congestion, and weakness. Non-selective alpha blockers such as terazosin and doxazosin may also require titration as they can cause syncope if the dose is too high. Side effects can also include erectile dysfunction.

The 5-alpha-reductase inhibitor finasteride and dutasteride are another treatment option. These medications inhibit 5a-reductase, which in turn inhibits production of DHT, a hormone responsible for enlarging the prostate. Effects may take longer to appear than alpha blockers, but they persist for many years. When used together with alpha blockers, a reduction of BPH progression to acute urinary retention and surgery has been noted in patients with larger prostates. Side effects include decreased libido and ejaculatory or erectile dysfunction.

Antimuscarinics such as tolterodine may also be used, especially in combination with alpha blockers. They act by decreasing acetylcholine effects on the smooth muscle of the bladder, thus helping control symptoms of an overactive bladder.

An estrogen reabsorption inhibitor such as mepartricin improves voiding, reduces urological pain and improves quality of life in patients with chronic non-bacterial prostatitis and benign prostatic hyperplasia. Mepartricin may interfere with the reabsorption of estrogens in the gut, leading to increased fecal estrogen excretion. It reduces 17 β estradiol concentration in enterohepatic circulation and decreases estrogen levels in the prostate. The effect of mepartricin on the reabsorption of estrogens was evaluated in studies in vitro and in vivo.

Sildenafil citrate shows some symptomatic relief, suggesting a possible common cause with erectile dysfunction. Tadalafil was considered then rejected by NICE in the UK for the treatment of symptoms associated with BPH. In 2011, the U.S. Food and Drug Administration approved tadalafil to treat the signs and symptoms of benign prostatic hyperplasia, and for the treatment of BPH and erectile dysfunction (ED), when the conditions occur simultaneously.

Clean intermittent self-catheterization

Intermittent urinary catheterization is used to relieve the bladder in patients with urinary retention. Catheterization has been practiced since antiquity, but was first mentioned in modern medicine in 1880 and then reintroduced by Lapides and colleagues in 1972. Self-catheterization is an option in BPH when the bladder is difficult or impossible to completely empty. Urinary tract infection is the most common complication of intermittent catheterization. Several techniques and types of catheter are available, including sterile (single-use) and clean (multiple use) catheters, but none is superior to others in reducing the incidence of urinary tract infection based on current information.

Minimally invasive therapies

Although medication is often prescribed as the first treatment option, many patients do not achieve success with pharmacotherapy. They may not achieve sustained improvement in symptoms or may stop taking the medication because of side-effects. There are options for treatment in a urologist's office before proceeding to surgery. The two most common types of office-based therapies are transurethral microwave thermotherapy (TUMT) and transurethral needle ablation (TUNA). Both of these procedures rely on delivering enough energy to create sufficient heat to cause cell death (necrosis) in the prostate. The goal is to cause enough necrosis so that, when the dead tissue is reabsorbed by the body, the prostate shrinks, relieving the obstruction of the urethra. These procedures are typically performed with local anesthesia, and the patient returns home the same day. Some urologists have studied and published long-term data on the outcomes of these procedures, with data out to five years. The most recent American Urological Association (AUA) Guidelines for the Treatment of BPH in 2003 lists minimally invasive therapies including TUMT and TUNA as acceptable alternatives for certain patients with BPH. However, European guidelines do not recommend the use of TUMT or TUNA over surgery.

Transurethral microwave therapy (TUMT) was originally approved by the United States Food and Drug Administration (FDA) in 1996, with the first generation system by EDAP Technomed. Since 1996, other companies have received FDA approval for TUMT devices, including Urologix, Dornier, Thermatrix, Celsion, and Prostalund. Multiple clinical studies have been published on TUMT. The general principle underlying all the devices is that a microwave antenna that resides in a urethral catheter is placed in the intraprostatic area of the urethra. The catheter is connected to a control box outside of the patient's body and is energized to emit microwave radiation into the prostate to heat the tissue and cause necrosis. It is a one-time treatment that takes approximately 30 minutes to 1 hour, depending on the system used. It takes approximately 4 to 6 weeks for the damaged tissue to be reabsorbed into the patient's body. Some of the devices incorporate circulating coolant through the treatment area with the intent of preserving the urethra while the microwave energy heats the prostatic tissue surrounding the urethra.

Transurethral needle ablation (TUNA) operates with a different type of energy, radio frequency (RF) energy, but is designed along the same premise as TUMT devices, that the heat the device generates will cause necrosis of the prostatic tissue and shrink the prostate. The TUNA device is inserted into the urethra using a rigid scope much like a cystoscope. The energy is delivered into the prostate using two needles that emerge from the sides of the device, through the urethral wall and into the prostate. The needle-based ablation devices are very effective at heating a localized area to a high enough temperature to cause necrosis. The treatment is typically performed in one session, but may require multiple sticks of the needles depending on the size of the prostate.

In 2009, Israeli physicians reported the discovery that BPH develops as a result of an impairment in the venous drainage system of the testicles and prostate in elderly males. As a result, the prostate is exposed to high concentrations of testosterone. They reported statistically significant declines in prostate volume and nocturia using an interventional radiological technique that involves percutaneous venography and sclerotherapy of the internal spermatic vein network, including associated venous bypasses and retroperitoneal collaterals. The nonsurgical method, known as "super-selective intraprostatic androgen deprivation therapy" reversed the size of the gland and improved symptoms without the potential side effects and complications of classic surgery.

Surgery

If medical treatment fails, and the patient elects not to try office-based therapies or the physician determines the patient is a better candidate for transurethral resection of prostate (TURP), surgery may need to be performed. In general, TURP is still considered the gold standard of prostate interventions for patients who require a procedure. This involves removing (part of) the prostate through the urethra. However, after this endoscopic surgery the ejaculations are dry and the person becomes sterile. For a male who wishes to father a child this is not the procedure of choice. Over the past couple of decades efforts to find newer surgical methods have resulted in newer approaches and different types of energies being used to treat the enlarged gland. However some of the newer methods for reducing the size of an enlarged prostate, have not been around long enough to fully establish their safety or side-effects. These include various methods to destroy or remove part of the excess tissue while trying to avoid damaging what remains. Transurethral electrovaporization of the prostate (TVP), laser TURP, visual laser ablation (VLAP), ethanol injection, and others are studied as alternatives.

Newer techniques involving lasers in urology have emerged in the last 5–10 years, starting with the VLAP technique involving the Nd:YAG laser with contact on the prostatic tissue. A similar technology called photoselective vaporization of the prostate (PVP) with the GreenLight (KTP or LBO crystal) laser have emerged very recently. This procedure involves a high-power 180-watt 532 nm wavelength laser with a 650-micrometre laser fiber inserted into the prostate. This fiber has an internal reflection with a 70-degree deflecting angle. It is used to vaporize the tissue to the prostatic capsule. GreenLight 532 nm lasers target haemoglobin as the chromophore and typically have a penetration depth of 0.8 mm (twice as deep as holmium). The procedure termed Holmium Laser Ablation of the Prostate (HoLAP) has been gaining acceptance around the world. Like KTP, the delivery device for HoLAP procedures is a 550 um disposable side-firing fiber that directs the beam from a high-power 100-watt laser at a 70-degree angle from the fiber axis. The holmium wavelength is 2,140 nm, which falls within the infrared portion of the spectrum and is invisible to the naked eye. Whereas GreenLight relies on haemoglobin as a chromophore, water within the target tissue is the chromophore for Holmium lasers. The penetration depth of Holmium lasers is <0.4 mm, avoiding complications associated with tissue necrosis often found with the deeper penetration and lower peak powers of Nd:YAG lasers used in the 1990s.

HoLEP, Holmium Laser Enucleation of the Prostate, is another Holmium laser procedure reported to carry fewer risks compared with either TURP or open prostatectomy. HoLEP is largely similar to the HoLAP procedure; the main difference is that this procedure is typically performed on larger prostates. Instead of ablating the tissue, the laser cuts a portion of the prostate, which is then cut into smaller pieces and flushed with irrigation fluid. As with the HoLAP procedure, there is little bleeding during or after the procedure. A recent review concludes that HoLEP is superior to TURP and should become the new gold standard.

Both wavelengths, GreenLight and Holmium, ablate approximately one to two grams of tissue per minute.

Post-surgical care often involves placement of a Foley catheter or a temporary prostatic stent to permit healing and allow urine to drain from the bladder.

In summary, the surgical techniques used are:

• Open prostatectomy: not usually performed nowadays, even if results are very good.
• Trans-urethral resection of the prostate (TURP): the gold standard.
• Transurethral incision of the prostate (TUIP): rarely performed; the technique is similar to TURP but less definitive.
• Laser vaporization of the prostate: common treatment.
• Transurethral microwave therapy (TUMT): similar to laser ablation, but less effective and much less used.
• Transurethral needle ablation (TUNA): not very effective.
• Holmium laser enucleation of the prostate (HoLEP): more and more used, it will probably replace TURP in the future.

Alternative medicine

Herbal remedies are a commonly used treatment, and several are approved in European countries and available in the USA. Saw palmetto extract from Serenoa repens is one of the most commonly used and studied, having shown some promise in early studies. Later trials of higher methodological quality have shown it to be no better than placebo in both symptom relief and decreasing prostate size. Other herbal medicines include beta-sitosterol from Hypoxis rooperi (African star grass) and pygeum (extracted from the bark of Prunus africana), while there is less substantial support for the efficacy of pumpkin seed (Cucurbita pepo) and stinging nettle (Urtica dioica) root. A systematic review of Chinese herbal medicines found that the quality of studies was insufficient to indicate any superiority over Western medicines.

Epidemiology

Disability-adjusted life year for benign prostatic hyperplasia per 100,000 inhabitants in 2004.

  no data

  less than 20

  20–28

  28–36

  36–44

  44–52

  52–60

  60–68

  68–76

  76–84

  84–92

  92–100

  more than 100

Globally, benign prostatic hyperplasia affects about 210 million males as of 2010 (6% of the population). The prostate gets larger in most men as they get older. For a symptom-free man of 46 years, the risk of developing BPH over the next 30 years is 45%. Incidence rates increase from 3 cases per 1000 man-years at age 45–49 years, to 38 cases per 1000 man-years by the age of 75–79 years. While the prevalence rate is 2.7% for men aged 45–49, it increases to 24% by the age of 80 years.

References

Further reading

• Christensen, Tyler L.; Andriole, Gerald L. (February 2009). "Benign Prostatic Hyperplasia: Current Treatment Strategies". Consultant 49 (2): 115–22. 
• Roy Johnson, Self-Catheter for Men

External links

• Extrinsic Compression by Prostate

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 前立腺肥大症の内科的治療 medical treatment of benign prostatic hyperplasia
• 2. 前立腺肥大症のの臨床症状および診断的評価 clinical manifestations and diagnostic evaluation of benign prostatic hyperplasia
• 3. 良性前立腺肥大症の経尿道的手技による治療 transurethral procedures for treating benign prostatic hyperplasia
• 4. 前立腺肥大症の疫学および病因 epidemiology and pathogenesis of benign prostatic hyperplasia
• 5. 前立腺特異的抗原（PSA）の測定 measurement of prostate specific antigen

English Journal

• Pelvic ultrasound evaluation for benign prostatic hyperplasia: prediction of obstruction.

• Rukstalis DB.Author information Department of Urology, Wake Forest University School of Medicine, Winston-Salem, NC, USA, dbrukstalis@me.com.AbstractGlobal improvements in water quality, management of infectious diseases, and other medical therapeutics have resulted in a growing population of healthy aging men. One obligate anatomic consequence of aging for these men is the development of benign prostatic hyperplasia (BPH) with secondary bladder outlet obstruction. Although the voiding symptoms associated with the change in bladder health over time predominantly impact the quality of a man's daily experience, there are also significant medical consequences of BPH that require intervention. It is a challenge to distinguish men who are at risk for these medical consequences from the much larger population of older men with voiding symptoms (lower urinary tract symptoms, LUTS). A variety of national guidelines have been developed to establish a diagnostic paradigm for meeting this challenge, but all suffer from inadequate sensitivity for the early identification of men at risk for permanent bladder injury. It is likely that the application of a thorough pelvic ultrasound designed to identify the pertinent anatomic aspects of both the bladder and prostate will improve the sensitivity of these diagnostic paradigms, with subsequent improvement in the outcomes for men with BPH/LUTS.
• Current urology reports.Curr Urol Rep.2014 May;15(5):403. doi: 10.1007/s11934-014-0403-8.
• Global improvements in water quality, management of infectious diseases, and other medical therapeutics have resulted in a growing population of healthy aging men. One obligate anatomic consequence of aging for these men is the development of benign prostatic hyperplasia (BPH) with secondary bladder
• PMID 24658830

• Interleukin-18 may lead to benign prostatic hyperplasia via thrombospondin-1 production in prostatic smooth muscle cells.

• Hamakawa T1, Sasaki S, Shibata Y, Imura M, Kubota Y, Kojima Y, Kohri K.Author information 1Department of Nephro-Urology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.AbstractBACKGROUND: Although inflammation plays an important role in the development of benign prostatic hyperplasia (BPH), little is known about the exact mechanism underlying this pathogenesis. Here, we investigated the relationship between the inflammatory reaction and BPH.
• The Prostate.Prostate.2014 May;74(6):590-601. doi: 10.1002/pros.22773. Epub 2014 Feb 24.
• BACKGROUND: Although inflammation plays an important role in the development of benign prostatic hyperplasia (BPH), little is known about the exact mechanism underlying this pathogenesis. Here, we investigated the relationship between the inflammatory reaction and BPH.METHODS: cDNA microarray analys
• PMID 24615654

• Surgical intervention for symptomatic benign prostatic hyperplasia is correlated with expression of the AP-1 transcription factor network.

• Lin-Tsai O1, Clark PE, Miller NL, Fowke JH, Hameed O, Hayward SW, Strand DW.Author information 1Department of Urologic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.AbstractBACKGROUND: Approximately one-third of patients fail medical treatment for benign prostatic hyperplasia and associated lower urinary tract symptoms (BPH/LUTS) requiring surgical intervention. Our purpose was to establish a molecular characterization for patients undergoing surgical intervention for LUTS to address therapeutic deficiencies.
• The Prostate.Prostate.2014 May;74(6):669-79. doi: 10.1002/pros.22785. Epub 2014 Feb 5.
• BACKGROUND: Approximately one-third of patients fail medical treatment for benign prostatic hyperplasia and associated lower urinary tract symptoms (BPH/LUTS) requiring surgical intervention. Our purpose was to establish a molecular characterization for patients undergoing surgical intervention for
• PMID 24500928

Japanese Journal

• 前立腺肥大症に対してデュタステリド投与後に前立腺生検を施行した症例の臨床病理学的検討

• 遠藤 匠,神谷 直人,矢野 仁 [他]
• 日本泌尿器科学会雑誌 = The Japanese journal of urology 106(3), 156-162, 2015-07
• NAID 40020532378

• 前立腺肥大症に伴う夜間頻尿 (特集 夜間頻尿を診る : これを読めば解決!) -- (診断と治療)

• 濱川 隆,窪田 泰江,佐々木 昌一
• 臨床泌尿器科 = Japanese journal of clinical urology 69(6), 475-479, 2015-05
• NAID 40020445948

• 当院における抗血栓療法症例に対するPVPの安全性と有用性

• 宮内 聡秀,柚須 恒,神崎 正徳
• 西日本泌尿器科 = The Nishinihon journal of urology 77(1), 6-11, 2015-01
• NAID 40020331494

Related Links

• Benign prostatic hyperplasia - Wikipedia, the free encyclopedia

Benign prostatic hyperplasia (BPH), also called benign enlargement of the prostate (BEP), adenofibromyomatous hyperplasia and benign prostatic hypertrophy (technically incorrect usage), is an increase in size of the prostate. BPH involves ...

Related Pictures

---

★リンクテーブル★

リンク元	「前立腺肥大症」
関連記事	「prostatic」

「前立腺肥大症」

　　[★]

英

benign prostatic hyperplasia BPH, benign prostatic hypertrophy, prostatic hyperplasia

同

前立腺肥大

関

前立腺

定義

• 加齢に従い、前立腺の内腺が腫大し、尿路を圧迫して排尿障害を呈する疾患。

疫学

• 前立腺の肥大(内腺)は30-40歳代から始まり、50歳代には顕著となり、70歳代以降ではほぼ全例に認められるが、臨床症状を呈するのはこの一部である(10-20%)。

病因

前立腺肥大症	前立腺の内腺
前立腺癌	前立腺の外腺

病態

• 肥大した前立腺により尿路を刺激し、さらには閉塞して、ついには完全尿閉に至る。

重症分類

• 前立腺体積が20ml以下では軽症、前立腺体積が20-50ml以下では中等症、前立腺体積が50ml以上では重症

症状

YN.E-86 SURO.258

病期は3つに分けられる：(1)第1病期 刺激期、(2)第2病期 残尿発生期、(3)第3病期 慢性尿閉期

病期		病態	症状
第1病期	刺激期	腫大した前立腺による後部尿道(膀胱頚部、前立腺尿道)の刺激	軽度の排尿困難、夜間頻尿、排尿時不快感
第2病期	残尿発生期	残尿(50-150ml)の発生	排尿困難(いきみながらの排尿)。残尿。急性尿閉(飲酒、抗コリン薬、長時間の乗り物の乗車)
第3病期	慢性尿閉期	さらなる残尿(300ml以上)、膀胱の過伸展(排尿筋だけでは排尿できない)	奇異性尿失禁、腎機能低下による尿毒症症状

検査

• 腹部超音波検査

[show details]

診断

参考1

• 病歴、理学的検査、尿検査、血清クレアチニン測定、PSA測定、尿流測定、残尿測定、排尿時における排尿筋圧、尿流率同時測定法、内視鏡検査、画像診断(超音波検査法、静脈性腎盂造影法、排尿時膀胱尿道造影法、逆行性尿道造影法など)などにより行う。

診断のステップ

• 1. 病歴、理学的検査(直腸診)、尿検査、血清クレアチニン測定、PSA測定　→　排尿障害の症状が前立腺肥大症によるものと考えられるか判断
• 2. 国際前立腺症状スコアの評価：(≦7点)経過観察。(≧8点)尿流測定、残尿測定、PFSを施行　→　尿道閉塞の程度を把握し治療
• 3. (治療する場合)QOLスコアを考慮して治療方法を選択。
• 4. (追加検査)内視鏡検査、画像診断法：ルーチン検査法ではない。外科的治療の準備や合併疾患の疑診例に対して実施する。

治療

SURO.258 参考1 参考3

• 治療のmodality

• 薬物療法

• α1ブロッカー：プラゾシン(副：起立性低血圧)、タムスロシン(副：血圧を下げないが、射精障害がある)　　←　　肥大した前立腺の圧迫の他に膀胱頚部、尿道、前立腺の平滑筋(α1受容体)の過剰収縮によっても排尿困難が起きているため、尿道内圧を下げ症状緩和しうる。
• 抗アンドロゲン薬：クロルマジノン、アリルエストレノール。前立腺の縮小作用。(副：性器脳障害、肝機能障害)
• 5α還元酵素阻害薬：前立腺の縮小作用。
• その他：漢方製剤(猪苓湯、八味地黄丸)、花粉製剤、アミノ酸製剤　　←　　自覚症状の改善にとどまる

• 加熱療法：ハイパーサーミア(前立腺内加熱温度45℃以下)と高温度療法(前立腺内加熱温度45℃以上)がある。熱源はマイクロ波、RF波、レーザー波などがある。レーザー療法、温熱療法の長期成績は未確立。

• 高温度療法：プロスタトロン、TUBAL-T

• 手術療法

• 前立腺被膜下摘除術
• 経尿道的前立腺摘除術 TUR-P

出典不明

• 第1期：薬物療法：α遮断薬、抗アンドロゲン薬、漢方薬
• 第2期：手術療法：経尿道的前立腺切除術、前立腺被膜下摘出術

• 「手術の際に、前立腺を取り巻く前立腺神経叢を傷つけると陰茎海綿体神経との交通が断たれ、勃起機能が失われる」と思われる (N.390)

参考

• 1. 2001年 前立腺肥大症 ガイドライン
• 2. 日本Endourology・ESWL学会によるBPHガイドライン

http://jsee.umin.ac.jp/images/guideline.pdf

• 3. [信頼度不明]前立腺肥大症の漢方治療【百花園漢方薬局】

http://www.est.hi-ho.ne.jp/abes/hyakkaen21/tokusiyu26.htm

国試

• 104I054

「prostatic」

　　[★]

• adj.

• 前立腺の

関

prostate、prostate gland