Benign prostatic hyperplasia (BPH) for short, benign prostatic hyperplasia or prostatic hyperplasia, is one of the most common urological diseases in elderly men. Benign prostatic hyperplasia is actually a pathological diagnosis, which mainly manifests as prostatic gland epithelial or stromal hyperplasia, not cell hypertrophy, so it is not accurate to call it prostatic hypertrophy in the past. Because benign prostatic hyperplasia can lead to benign prostate enlargement (Benign Prostatic Enlargement, BPE), bladder outlet obstruction caused by benign prostatic enlargement can cause a series of urination symptoms. In recent years, many scholars have discovered that the so-called symptoms of prostate hyperplasia in elderly men are not completely related to bladder outlet obstruction caused by enlarged prostate. The changes in detrusor function of the elderly can also produce similar symptoms. These changes in detrusor function may be long-term. Bladder outlet obstruction is caused by detrusor aging, so lower urinary tract symptoms (LUTS) are advocated internationally to describe a series of urination symptoms in elderly men. Therefore, benign prostatic hyperplasia does not necessarily have benign prostatic enlargement, and benign prostatic enlargement does not necessarily cause bladder outlet obstruction. Usually the so-called symptoms of benign prostatic hyperplasia mostly refer to a series of lower urinary tract symptoms caused by bladder outlet obstruction due to benign prostatic hyperplasia and benign prostate enlargement.
Etiology and pathogenesis
The cause of the disease is still unclear. The aging and functional testes produce testosterone through 5α-reductase into dihydrotestosterone (DHT) which is the basis for hyperplasia. DHT accounts for 90% of the androgen in the human prostate, which is produced from the testes. The androgens produced by the adrenal glands account for only 10%. Androgens are not only necessary for the proliferation and differentiation of normal cells in the prostate, but also can inhibit cell death. It is thought that reducing death may be more important. The eunuch whose testicles were removed before puberty had a life-long underdeveloped prostate. Even in old age, the prostate was underdeveloped because of lack of androgens. For those who are congenital lack of 5α-reductase, their prostate is underdeveloped. Clinically, 5α-reductase is also used to treat benign prostatic hyperplasia to shrink it.
Testosterone and dihydrotestosterone bind to the same receptor in the prostate, but the affinity of dihydrotestosterone is 5 times stronger than testosterone, and it is also more stable. The prostate's response to androgen receptors is lifelong, even reaching a high concentration in old age. On the contrary, the development of the penis is controlled by androgen receptors, but it stops growing when it is uncontrolled in adulthood. The nuclear androgen receptor in prostate hyperplasia tissue is higher than that in normal tissue.
The effect of estrogen on the pathogenesis of benign prostatic hyperplasia is proven through experiments in dogs, and there is no clear evidence in humans. The absolute value of estrogen plasma levels and the ratio of testosterone to testosterone in elderly men are elevated, and estrogen in benign prostatic hyperplasia also increases, and the level of estradiol in the peripheral blood of large prostate patients is also higher.
The regulation of programmed cell death (apoptosis) is important for maintaining the volume of the prostate. Testosterone and dihydrotestosterone inhibit cell apoptosis, and orchiectomy can increase the apoptosis of the glandular epithelium and the distal part of the duct. The loss of balance between cell proliferation and apoptosis is the cause of prostate hyperplasia. Many growth factors are involved in the process of proliferation and apoptosis. Cell proliferation interacts with BEGF, EGF, KGF, and IGF, and is regulated by dihydrotestosterone. TGEβ inhibits epithelial proliferation.
According to the theory of stroma and epithelium, a large number of experiments have proved that the interaction between prostate epithelium and stroma, stromal cells can regulate the growth of epithelium and other stroma through paracrine or autocrine mechanisms, and a variety of growth factors participate in the role.
Stem cell theory, old stem cells block their maturation process and prevent their apoptosis.
Family members have genetic genes, first-level family members have benign prostatic hyperplasia surgery, the chance of benign prostatic hyperplasia is 4.2 times higher than the control group; 50% of patients undergoing surgery before the age of 60 may be genetically related, while patients over 60 years of age have genetic related Accounted for only 9%. The volume of benign prostatic hyperplasia of family attributes is also larger than that of sporadic, 82.7ml and 55.5ml respectively.
Prostatic hyperplasia starts in the glands (transition zone) surrounding the seminal urethra, which accounts for 5% of the prostate tissue. The remaining 95% consists of 3/4 of the peripheral area and 1/4 of the central area. The peripheral area is the starting site of prostate cancer. When the prostate is hyperplasia, the peripheral area is squashed into a pseudocapsule, and the central area is the site through which the ejaculatory duct passes. Atypical hyperplasia in the prostate tissue may be a precancerous state.
The glands of prostatic hyperplasia may squash the peripheral glands to form a pseudocapsule, which has a clear boundary with the hyperplastic glands. The hyperplastic glands may develop in all directions, and may become lobulated, causing the urethra of the prostate to bend and elongate, compress the urethra, and move the seminal caruncle down to close to the external sphincter.In the early years, prostate hyperplasia was divided into several types, and there is still reference value: ① the middle lobe alone increases by 30%, ② the bilateral lobes increase by 14%, ③ the bilateral and middle lobes increase by 22%, ④ the posterior joint hyperplasia, glandular Body hyperplasia caused 14% of the obstruction of the formation of the posterior lip of the bladder neck, and 17% of the bilateral lobes and posterior joint hyperplasia. These different parts of prostate hyperplasia cause varying degrees of urethral obstruction, so the size of the prostate is not closely related to the degree of obstruction. Sometimes the prostate with less than 10g at the exit of the bladder can cause severe obstruction and difficulty in urination, but the proliferation of the two sides of the leaf that is several times larger than it does not affect urination.
The occurrence and development of prostate hyperplasia are slow, urination obstruction makes the bladder detrusor thicken, the mucosal surface appears as trabeculae, and in severe cases, pseudo diverticula form. Hypertrophy of the interureteral crest can aggravate dysuria. Long-term difficulty in urination makes the bladder highly inflated, the internal pressure rises, the end of the ureter loses its valve function, and vesicoureteral reflux occurs, causing hydronephrosis, renal insufficiency, and obstruction causing urinary retention, which is prone to infection and stone formation.
The symptoms of benign prostatic hyperplasia generally appear after the age of 50. The severity of symptoms depends on the degree of obstruction, irritation, detrusor function, and whether there are complications such as infection and stones, not the size of the prostate. Clinical symptoms can be mild and severe.
The symptoms of prostate hyperplasia can basically be divided into two categories:
Obstruction: urinary hesitancy, intermittent urinary line, terminal dribbling, thin and weak urinary line, prolonged urination time, feeling of incomplete urination, full urinary incontinence, etc.
Irritation: frequent urination, urgency, increased nocturia, low urine output, urge incontinence.
In recent years, with the development of urodynamics, 50% to 80% of patients with benign prostatic hyperplasia have been found to have unstable bladder. Routine examinations are considered to be prostate hyperplasia. Urodynamic examination found that about 1/4 of the patients did not have bladder outlet obstruction, which means that regardless of whether these patients have difficulty urinating or have irritating symptoms, it is not caused by bladder outlet obstruction caused by prostate hyperplasia , Which is related to changes in detrusor function. Therefore, while understanding the patient’s symptoms, one should also pay attention to whether there are corresponding diseases that may cause detrusor dysfunction, such as diabetes and cerebrovascular accidents. If it is necessary to further determine the cause of the symptoms, urodynamic examinations are required.
In the obstructive symptoms, the thinning and weakness of the urine line is caused by the pressure of the prostatic hyperplasia on the urethra, which can appear in the early stage of prostatic hyperplasia. Urinary hesitancy is the prolongation of the time it takes for the detrusor muscles to contract to make the bladder pressure exceed the urethral resistance. The urinary thread is interrupted because the detrusor muscle cannot maintain its pressure until the end of urination. Sometimes urine drips after the end of urination. Patients often have a feeling of incomplete urination. In severe cases, urinary retention occurs, the bladder cannot be emptied, there is residual urine, the bladder is often filled, the effective volume is reduced, and the time between urination is shortened. The enlarged prostate makes the bladder detrusor respond more frequently to urination. If the prostate is large and protrudes into the bladder, the bladder capacity will decrease and frequent urination will be more obvious.
Frequent urination and increased nocturia frequency are irritation symptoms of urination and are also symptoms that appear in the early stage of prostate hyperplasia. Frequent urination can be considered if the number of urination exceeds 8 times a day. In addition to the above-mentioned reduction in bladder capacity due to incomplete emptying of obstruction and enlarged prostate, prostate hyperemia and unstable bladder can also cause frequent urination. Nocturia is the weakening of cerebral cortex inhibition during sleep, the decrease of urethra and urethral sphincter tension, which increases the frequency of nocturia. Urgency and dysuria among the irritation symptoms are not common in prostate hyperplasia, and may be caused by co-infection and/or urolith formation. If the prostate hyperplasia is dominated by irritation and the prostate enlargement is not obvious, it should be considered that there may be other reasons for urination disorders.
Urinary retention and filling urinary incontinence, as well as renal damage are the late symptoms of prostate hyperplasia. Severe obstruction, residual urine in the bladder, the greater the residual urine volume, the detrusor gradually loses its ability to contract, and urinary incontinence may occur. Overfilling of the bladder causes urine to overflow from the urethra, which is called filling incontinence. When filling urinary incontinence, the pressure in the bladder rises, which can cause fluid accumulation in the ureters and kidneys, which can damage kidney function.
Hematuria is rare in prostate hyperplasia and may be caused by local congestion, such as co-infection and urolithiasis, hematuria with bladder irritation.
Prostatic hyperplasia can sometimes cause abdominal pain, especially lower abdominal distension and pain. When renal insufficiency occurs, loss of appetite, nausea and vomiting, pallor, lethargy, etc. may occur.
Long-term dysuria, increased abdominal pressure may cause inguinal hernia, prolapse and hemorrhoids.
The following aspects should be included:
1. Medical history: BPH is a disease of the elderly. If the patient has similar symptoms before the age of 50, the possibility of other diseases should be considered. History of genitourinary system, surgery, injury, neurological disease, history of diabetes, certain drugs may affect urinary function, especially psychiatric drugs.
2. Symptom evaluation: At present, the symptoms of prostate hyperplasia are quantified, and the international prostate symptom score (I-PSS) and quality of life index (QOL) are widely used (see Table 1). In addition to urinary symptoms, the quality of life index also claims to include sexual function. Symptom evaluation may not only assess the severity of symptoms, but also judge the efficacy of treatment methods.
Table 1. International Prostate Symptom Score (I-PSS)
International Prostate Symptom Score (I-PSS)
In the past month, did you have the following symptoms
Less than 1/5
Less than 1/2
More than 1/2
Do you often feel incomplete urine
Is the interval between urination often shorter than 2 hours
Do you often have intermittent urination
Do you often have difficulty holding urine
Are there frequent thinning of urine lines
Do you often need to strain to urinate
Need to get up to urinate several times from falling asleep to getting up early
Total symptom score =
Quality of life affected by urination symptoms
Not so satisfied
If you always have current urination symptoms in the second half of your life, what do you think
Quality of Life Score (QOL)=
3. Imaging examination: ultrasound, X-ray examination, CT, MRI, etc.
Ultrasound examination is necessary for benign prostatic hyperplasia. It can also examine the kidneys, ureters, bladder, and prostate. Use abdominal wall or transrectal ultrasound to check the size and shape of the prostate, whether it protrudes into the bladder, whether the ridge structure is disordered, whether there are hypoechoic nodules, and can also determine the residual urine volume. Both economical and non-invasive. The inspection findings have important reference value for choosing treatment methods.
Urinary system X-ray films, angiography, CT, MRI are only suitable for people with hematuria, urolithiasis, history of infection, renal insufficiency, etc., and are not used as routine examinations.
4. Laboratory examination: hematuria routine, serum electrolyte, liver and kidney function. If there is hematuria, proteinuria, and pyuria, urinary bacteriology culture and imaging are needed to monitor whether there are infections, urolithiasis, tumors and other diseases.
5. Measurement of urinary flow rate: Prostatic hyperplasia has difficulty urinating, and urinary flow rate is a good way to objectively check urinary function. The urine output during the urine flow rate inspection should exceed 150ml, and the urine flow rate should be measured in a quiet environment. Because the urine flow rate results vary greatly among individuals, more than two re-examinations should be done if necessary. If the maximum urinary flow rate Qmax<15ml/s and the average urinary flow rate Qave<8ml/s, it indicates dysuria. Because the urine flow rate is determined by the interaction between the contractile function of the bladder detrusor and the urethral resistance, the change of the urine flow rate is not only related to the lower urinary tract resistance, but may also be affected by the change of the detrusor function. Therefore, the decrease in urine flow rate cannot be determined as lower urinary tract obstruction or impaired detrusor contractility. If suspicious or medical history suggests that there may be diseases that affect detrusor function, such as diabetes or neurological diseases, urodynamic tests should be performed before invasive treatment of the prostate to determine the exact cause of the patient’s urination disorder.
6. The residual urine volume of the bladder: The choice of treatment methods and the evaluation of the efficacy are very important. It is best to measure by non-invasive transabdominal ultrasound. At the same time, you can also observe the shape of the bladder, whether there are bladder stones, diverticula, and middle lobe hyperplasia. Urinary catheterization is the most reliable result of residual urine, but it is an invasive examination and may lead to infection. It should be carefully considered. In the past, residual urine >60ml was considered to be an indication for surgery. Now, residual urine exceeding 150ml is generally regarded as one of the indicators of severe urination disorders. When measuring residual urine, attention should be paid to the environment of urination and whether the bladder urine volume is appropriate. For example, even if the bladder of normal healthy people stores more than 500ml of urine, it will cause the existence of residual urine. It should be emphasized that the residual urine volume may also be caused by the decrease in detrusor contractility. If medical history or physical examination suggests that there may be related diseases that may affect detrusor function, urodynamic tests should be performed to identify them.
7. Serum prostate specific antigen (prostatic specific antigen, PSA) is currently an important indicator for distinguishing prostate hyperplasia and prostate cancer.
Prostatic hyperplasia and prostate cancer are not two stages of the same disease, but two different diseases that can exist at the same time.As the prostate increases with age, the size of the prostate also increases. PSA is produced from the prostate epithelium and rarely enters the blood circulation. Only when its structure is disordered, PSA enters the matrix from the acinar and enters the blood circulation through the lymphatic vessels and capillaries. PSA is prostate specific antigen and not prostate cancer specific antigen. In order to distinguish these two diseases, PSA has three indicators: ① PSA density (PSAD), if PSAD>0.12ng/ml/ml, there is a possibility of cancer; ② PSA velocity (PSA velocity, PSAV): PSAV>0.75ng/ml per year, usually prostate cancer; ③ PSA age-specific value: PSA value is related to the size of the prostate, and the prostate volume increases with age, the normal value of PSA in each age group Yes: 2.5ng/ml for 40-49 years old, 3.5ng/ml for 59 years old, 4.5ng/ml for 60-69 years old, 6.5ng/ml for 70-79 years old. According to statistics, the above-mentioned normal values can be used to detect early prostate cancer under 60 years old, but the above-mentioned normal values above 60 years old may make prostate cancer missed.
8. Physical examination: If the patient is weak, pale, lethargic, high blood pressure, fast pulse, deep breathing, the possibility of uremia should be considered. Abdominal examination may reveal enlarged kidneys with tenderness at the spinal costal angle, indicating secondary hydronephrosis. The suprapubic bone should be checked for an inflated bladder. The surface of the bladder with urinary retention is smooth, soft and no nodules. Patients with a long medical history must pay attention to whether they have combined cancer, hemorrhoids, stenosis of the foreskin and whether the urethra is normal.
Digital rectal examination: First understand the tension of the anal sphincter, and the neurogenic bladder should be considered for anal relaxation. The prostate is enlarged, the middle sulcus disappears, and the surface is smooth. The hyperplastic nodules seen in histology are caused by the pseudocapsule formed by the outer peripheral zone. There is generally no nodular change on the digital examination. The enlargement on both sides of the prostate can be asymmetrical. If the enlarged part protrudes into the bladder, the digital rectal examination may not reach the upper edge of the prostate. The texture of the prostate can be relatively soft or hard, depending on the proportion of glandular components and fibrous smooth muscle. If the prostate enlarges irregularly, has nodules or even hard as stone, you should think of the possibility of prostate cancer.
During the physical examination, the bulbocavernosal muscle reflex, lower limb movement and perception should be monitored for normality, and possible neuropathy should be found.
9. Endoscopy: Cystoscopy is only applicable when there are diverticula, stones, tumors and other diseases in the bladder.
10. Urodynamic examination: Urodynamic examination is to understand the bladder storage function and urination function by measuring changes in bladder pressure during urination and urination, and to understand the correlation between detrusor pressure and urine flow rate during urination Bladder outlet resistance (ie, pressure-flow rate measurement analysis) to determine whether there is lower urinary tract obstruction is the most accurate method to diagnose whether there is bladder outlet obstruction. Indications for urodynamic examination in patients with benign prostatic hyperplasia: ①The medical history suggests that there may be neurological diseases or diabetes that affect detrusor function, ②There are obvious symptoms and signs that do not match, ③Conventional conservative treatment does not achieve the expected results and needs to know its exact Etiology, ④Before preparing for non-reversible treatment such as surgery for bladder outlet obstruction caused by suspected benign prostatic hyperplasia. Although pressure-flow rate analysis is currently used to determine whether there is an obstruction of the bladder outlet, urodynamic tests are not necessarily required for patients who are mainly treated with drugs.
The drug treatment of BPH shows a trend of combination drugs.
Regarding the surgical treatment of BPH, compare the advantages and disadvantages of several surgical methods currently in use. Alberston studied the current status of BPH surgery in the United States and found that TURP is still the most important surgical method for the treatment of BPH, and open surgery is rarely used.
Whether the BPH operation should be determined based on the results of urodynamic examinations has always been a clinically debated issue. In an expert discussion, Bushman believed that as age increases, the bladder of older men also declines. It is manifested by decreased contractility, decreased compliance, detrusor instability, and increased urinary outflow tract resistance. He believes that the success of surgery does not entirely depend on obstruction defined by strict urodynamic standards. Similar to the condition of heart disease, for most BPH patients with LUTS and decreased urine flow rate, prostatectomy can improve the bladder function of the patient and relieve the symptoms of the patient. Of course, there is currently no predictive standard, and surgeons are required to judge whether patients need surgery based on clinical results. If the patient has urodynamic changes in bladder function, whether to undergo surgery depends on whether he has an outflow tract obstruction caused by an enlarged prostate, such as a significantly enlarged prostate.
Plasma resection is a prostatectomy in normal saline, which has its advantages.Henry Ho compared TURIS (TUR in saline, transurethral resection of the prostate in saline) and TURP. The results showed that postoperative blood sodium levels of TURP patients were significantly lower than those of TURIS. Resection syndrome was 3.8% in the TURP group, but it did not occur in the TURIS group. But the incidence of urethral stricture in TURIS is 6.2%, while TURP is only 1.9%. In conclusion, TURIS is an effective prostatectomy with fewer complications than TURP.
Laparoscopy is not only used in radical prostatectomy, but also in the treatment of BPH. Rozet compared laparoscopic and open prostate removal. The results were similar in terms of intraoperative blood loss, blood transfusion rate, complications and postoperative washing time. Although the time of laparoscopic surgery is longer than that of open surgery (113min vs 64min), the indwelling catheter time is shorter (4.9 days vs 6.8 days). In addition, morphine consumption is small after laparoscopic surgery, and the hospital stay is shorter. The conclusion is that laparoscopic prostatectomy is a minimally invasive treatment with good clinical effect.
There are various laser applications in the treatment of BPH, such as green laser vaporization of the prostate (PVP) and holmium laser enucleation of the prostate (HoLEP). Bouchier-Hayes reported a randomized study comparing PVP and TURP. The results showed that the two techniques achieved similar results in improving urinary flow rate and patient symptoms, but the PVP group was significantly shorter in terms of catheter placement and hospital stay. In addition, there were fewer complications related to surgery in the PVP group. Elzayat reported 603 cases of HoLEP experience. The largest preoperative prostate was 351g, and the heaviest excised tissue weight was 340g. However, 1.8% of patients require intraoperative blood transfusion. In general, HoLEP is considered to be a safe and effective method for treating any enlarged prostate.