Benign Prostatic Hypertrophy Workup

In 2011, the American Urological Association (AUA) published a 2010 update to their Guideline on the Management of Benign Prostatic Hyperplasia. The update included an algorithm for the diagnosis and basic treatment of LUTS, which is presented below.^[2]

A prospective, multicenter study in 3 European countries called the Diagnosis Improvement in PrimAry Care Trial (D-IMPACT) found that in three quarters of the men aged 50 years and older who spontaneously reported LUTS to their general practitioner, those who were given an in-office diagnostic algorithm that included just the objective variables of age, PSS, and PSA were accurately diagnosed for BPH by their general practitioner.^[3]

Examine the urine using dipstick methods and/or via centrifuged sediment evaluation to assess for the presence of blood, leukocytes, bacteria, protein, or glucose.

This may be useful to exclude infectious causes of irritative voiding and is usually performed if the initial urinalysis findings indicate an abnormality.

Although BPH does not cause prostate cancer, men at risk for BPH are also at risk for prostate cancer and should be screened accordingly.

The 2010 update of the American Cancer Society (ACS) guideline for early detection of prostate cancer stresses the importance of involving men in the decision whether to test for prostate cancer. The ACS notes that PSA testing may reduce the likelihood of dying from prostate cancer but poses serious risks, particularly of treatment of prostate cancer that would not have caused ill effects if left undetected.^[4]

The ACS recommends that men receive information about the uncertainties, risks, and potential benefits associated with prostate cancer screening (ie, prostate-specific antigen [PSA] testing and digital rectal examination [DRE] for prostate cancer) at the following ages:

• Starting at age 50 years in men who are expected to live at least 10 more years
• Starting at age 45 years in men at high risk for prostate cancer (African-Americans and men with a close relative with prostate cancer)
• Starting at age 40 years in men with multiple close relatives with prostate cancer

A physician should discuss the risks and benefits of PSA screening with the patient. Notably, men with larger prostates may have slightly higher PSA levels.

These evaluations are useful screening tools for chronic renal insufficiency in patients who have high postvoid residual (PVR) urine volumes. A routine serum creatinine measurement is not indicated in the initial evaluation of men with lower urinary tract symptoms (LUTS) secondary to BPH.^[2]

Ultrasonography (abdominal, renal, transrectal) and intravenous urography are useful for helping determine bladder and prostate size and the degree of hydronephrosis (if any) in patients with urinary retention or signs of renal insufficiency. Generally, they are not indicated for the initial evaluation of uncomplicated LUTS.

Transrectal ultrasonography (TRUS) of the prostate is recommended in selected patients, to determine the dimensions and volume of the prostate gland. The success of certain minimally invasive treatments may depend on the anatomical characteristics of the gland. In patients with elevated PSA levels, TRUS-guided biopsy may be indicated.

Imaging of the upper tracts is indicated in patients who present with concomitant hematuria, a history of urolithiasis, an elevated creatinine level, high PVR volume, or history of upper urinary tract infection.

Other imaging studies, such as CT scanning and MRI, have no role in the evaluation and treatment of uncomplicated BPH.

The American Urological Association (AUA) has developed rigorous clinical practice guidelines for BPH based on the 1994 Agency for Healthcare Research and Quality clinical practice guidelines for BPH. In 2006, the AUA Practice Guidelines Committee updated the 1994 evidence-based guidelines for the diagnosis and treatment of BPH originally created under the auspices of the United States Department of Health and Human Services Agency for Health Care Policy and Research.^{[5, 6]}

The AUA 2010 BPH guideline update lowered the age of the Index Patient from age 50 years or older to age 45 years or older. Two algorithms were published: the algorithm for diagnosis and basic management of LUTS in the Approach section above, and an algorithm for detailed management of bothersome LUTS that persists after basic management, shown below.^[2]

These panels have established the following categories to classify diagnostic tests and studies. A recommended test is one that should be performed on every patient, whereas an optional test is of proven value in selected patients.

Recommended tests

A medical history should be taken to qualify and quantify voiding dysfunction. Identification of other causes of voiding dysfunction and medical comorbidities are essential to properly assess the condition and to determine conditions that may complicate treatment.

The physical examination consists of a focused physical examination and a neurologic examination. The physical examination includes a DRE to measure prostate size and to assess for abnormalities. The neurological examination is geared toward lower-extremity neurologic and muscular function, as well as anal sphincter tone. Examination of the phallus and foreskin occasionally reveals meatal stenosis, unretractable foreskin, penile ulcers, or foreign bodies such as warts.

PSA testing should be offered to any patient with a 10-year life expectancy in whom the diagnosis of prostate cancer would change management.

The severity of BPH can be determined with the International Prostate Symptom Score (IPSS)/American Urological Association Symptom Index (AUA-SI) plus a disease-specific quality of life (QOL) question. The AUA-SI for BPH is a set of 7 questions that has been adopted worldwide and yields reproducible and quantifiable information regarding symptoms and response to treatment. Questions concern incomplete emptying, frequency, intermittency, urgency, weak stream, straining, and nocturia.

The IPSS uses the same 7 questions as the AUA-SI, with the addition of an eighth question, known as the bother score, which is designed to assess perceived disease-specific QOL. The AUA-SI/IPSS questionnaire is available online. Based on the sum of the score for all 8 questions, patients are classified as 0-7 (mildly symptomatic), 8-19 (moderately symptomatic), or 20-35 (severely symptomatic).

Optional tests

Flow rate is useful in the initial assessment and to help determine the response to treatment. It may be performed prior to embarking on any active treatments, including medical treatment.

A maximal flow rate (Qmax) is the single best measurement, but a low Qmax does not help differentiate between obstruction and poor bladder contractility. For more detailed analysis, a pressure flow study (urodynamic testing) is required. A Qmax value of greater than 15 mL/s is considered by many to be normal. A value of less than 7 mL/s is widely accepted as low.

The results of flow rate measurements are somewhat effort- and volume-dependent. Therefore, the best plan to make a reasonable determination of significance is to obtain at least 2 tracings with at least 150 mL of voided volume each time.

Obtain postvoid residual urine in order to gauge the severity of bladder decompensation. It can be obtained invasively with a catheter or noninvasively with a transabdominal ultrasonic scanner. A high PVR (ie, 350 mL) may indicate bladder dysfunction and/or bladder outlet obstruction and may predict a poor response to treatment.

Although pressure flow studies are somewhat invasive, requiring catheterization of the urethra and placement of a transrectal pressure transducer, the findings may prove useful for evaluating for bladder outlet obstruction (BOO).

Urodynamic studies are the only way to help distinguish poor bladder contraction ability (detrusor underactivity) from outlet obstruction. BOO is characterized by high intravesical voiding pressures (>60 cm water) accompanied by low urine flow rates (Qmax < 15 mL/s).

Cytologic examination of the urine may be considered in patients with predominantly irritative voiding symptoms. Risk factors for bladder cancer (smoking, previous bladder cancer) should alert the physician to consider this noninvasive test.

Tests that are not recommended

Routine measurement of serum creatinine is not indicated in the initial evaluation of men with LUTS secondary to BPH.

Cystoscopy may be indicated in patients scheduled for invasive treatment or in whom a foreign body or malignancy is suspected. In addition, endoscopy may be indicated in patients with a history of sexually transmitted disease (eg, gonococcal urethritis), prolonged catheterization, or trauma. Findings may suggest urethral stricture as the cause of BOO, instead of BPH.

Flexible cystoscopy can be easily performed in several minutes in an office-based setting using topical gel-based intraurethral anesthesia without sedation.

BPH is characterized by a varying combination of epithelial and stromal hyperplasia in the prostate. Some cases demonstrate an almost pure smooth-muscle proliferation, although most demonstrate a fibroadenomyomatous pattern of hyperplasia.

In the bladder, obstruction leads to smooth-muscle-cell hypertrophy. Biopsy specimens of trabeculated bladders demonstrate evidence of scarce smooth-muscle fibers with an increase in collagen.