Benign prostatic hyperplasia is a histological term for a disease process that occurs in the periurethral region of the prostate and is characterized by stromal and epithelial cell hyperplasia.BPH is one of the most common diseases in older men. It usually manifests clinically as a series of bothersome lower urinary tract symptoms including: frequency, urgency, nocturia, weakness of urine flow, interruption of urine flow and a feeling of incomplete urination. The relationship between BPH and LUTS is complex and not all individuals with histologic changes of BPH will develop LUTS, nor is LUTS unique to BPH. When the term “BPH” is used clinically, it refers to a clinical syndrome that is characterized by an increase in prostate tissue growth or tone, with LUTS as a specific manifestation.
Diagnostic criteria
The key to the diagnosis of BPH is to determine that the LUTS is caused by BPH and to exclude other causes of LUTS. In the majority of cases, the diagnosis of BPH can be made by history, physical examination and urinalysis. Sometimes there are other tests that can be ordered to further exclude other causes of LUTS, to clarify the severity of the disease, to guide the choice of treatment and to predict the effectiveness of a particular treatment.
I. Initial evaluation items
(i) Medical history.
In men over 50 years old, BPH should be suspected if LUTS such as frequent urination, urgency, nocturia, weak urine flow, interrupted urine flow and incomplete urination sensation are present. it is recommended that the International Prostate Symptom Score (IPSS) be used to evaluate each patient suspected of having BPH to clarify the severity of LUTS. According to the score, it can be classified as mild (0-7), moderate (8-19) and severe (20-35). In order to exclude other causes or concomitant diseases causing urinary tract difficulties, we should also carefully inquire about previous history of urinary tract infection, injury or surgery, history of neurological disease that can cause bladder dysfunction, history of diabetes mellitus and history of pelvic surgery.
(b) Rectal examination and targeted physical examination.
The prostate gland can be found to be enlarged with a smooth and tough surface and the central groove disappears, but a normal size prostate does not exclude BPH. If hard nodules are found, prostate cancer should be suspected. Targeted physical examination includes: external genital examination, presence of indurated edema in both lower extremities, presence of a full bladder in the lower abdomen, and neurological examination (e.g., the patient’s general mental status, gait, neuromuscular function of the extremities and anal sphincter tone).
(iii) Urinalysis.
This can be performed by test paper examination or microscopic examination of urine sediment. Screening for hematuria and urinary tract infection.
(iv) Serum PSA assay.
Serum PSA assay can predict the natural course of BPH on one hand and can be used to screen for prostate cancer on the other hand. It overlaps with some patients with limited prostate cancer. The specificity of the diagnosis can be improved by measuring PSA velocity, free/total PSA ratio, and PSA density. The benefits and risks of PSA measurement should be discussed with the patient prior to the test. For most cases, rectal examination is sufficient to rule out limited prostate cancer causing urinary difficulties. Serum PSA measurement should only be selected for patients with a life expectancy greater than 10 years and in whom the presence of prostate cancer is known to alter the treatment regimen, or in whom PSA measurement may alter the treatment regimen for voiding symptoms.
(v) Urine cytology.
This test should be considered for patients with severe irritation, especially those with a history of smoking or other risk factors, in order to rule out bladder cancer.
II. Selective screening tests
The following two tests are not usually necessary for patients on watchful waiting and medication, but may be helpful in patients with complex medical histories (e.g., known neurological or other disorders affecting bladder function and a history of previous failed BPH therapy) and in patients who wish to undergo invasive therapy.
(i) Urine flow rate measurement.
Urine flow rate, especially the maximum urine flow rate (Qmax), may predict the patient’s response to surgery. Significant symptoms with a normal urinary flow rate suggest that these symptoms are most likely caused by non-prostatic factors. Highly suggestive of the presence of a power obstruction. Because of the poor stability of repeated urine flow rate measurements and the lack of appropriately designed studies, it is not possible to establish a “standard value” for decision-making purposes.
(ii) Residual urine measurement.
Large amounts of residual urine (e.g., greater than 350 ml) are indicative of bladder malfunction and deterioration, signaling a poor patient response to treatment. Like the urinary flow rate, there is no “standard” value for residual urine volume. Many patients with a significant amount of residual urine may be free of urinary tract infections, renal impairment and troublesome symptoms for a long time. The presence of residual urine is not a contraindication to watchful waiting or pharmacologic treatment, nor is there a set amount of residual urine that requires invasive treatment. Residual urine measurement is also indicated for a subset of patients treated non-invasively, and the safety of non-invasive treatment for patients with a certain amount of residual urine (200-300 ml) has not been verified.
III. Optional tests before invasive treatment
(i) Pressure-flow rate measurement.
It is the only test that can directly reflect the place of bladder, bladder outlet and prostate factors in lower urinary tract malfunction and symptom generation. It should be considered in patients who are considering invasive treatment, in patients with neurological disease, in patients with a history of previous invasive treatment for BPH, and in patients in whom pressure-flow rate measurements are likely to alter the treatment plan.
(ii) Urethrocystoscopy.
It is indicated in patients with a history of microscopic or carnal hematuria, risk factors for urethral strictures and bladder cancer, and a history of previous lower urinary tract surgery. The microscopic presentation of the prostatic urethra and bladder is not predictive of the response to treatment in patients with BPH, but is useful as a guide in the choice of treatment for patients who decide to undergo invasive treatment.
(iii) Transrectal or transabdominal prostate ultrasonography.
It is indicated for patients who choose invasive treatment. The size and morphology of the prostate gland is a guide to the choice of specific invasive treatment. In addition, the volume of the prostate measured by ultrasound can also predict the natural course of BPH and the response to 5-alpha reductase inhibitor therapy.
IV. Other tests
For patients undergoing initial evaluation, serum creatinine measurement is not necessary. If urinalysis and/or history and physical examination suggest underlying renal disease or urinary retention, serum creatinine determination is necessary prior to renal imaging. Ultrasound or excretory imaging of the upper urinary tract is not recommended for patients with typical BPH symptoms unless there is a history of hematuria, urinary tract infection, renal insufficiency, urinary stones, and surgery.
Criteria for judging efficacy
BPH is a benign disease, complications due to it are uncommon and the associated mortality rate is low. the impact of LUTS on the patient’s quality of life is highly variable and does not directly correlate with any measurable physiological indicators. The choice of treatment options for BPH depends first and foremost on the patient’s wishes and also takes into account the patient’s overall health status. Interventional treatment is more reasonable for patients suffering from moderate LUTS than for those who can tolerate severe LUTS.
Therefore, there is no single criterion to measure whether BPH is “cured” or “improved”. The treatment of BPH should only aim for a “desired outcome”, i.e., the elimination or alleviation of BPH-related complications such as refractory acute urinary retention, persistent granulomatous hematuria, bladder stones, recurrent urinary tract infections, and renal impairment. The treatment of LUTS due to BPH should be “satisfactory” to the individual patient, regardless of the severity of the LUTS itself.