Diagnosis of Benign Prostatic Hyperplasia (BPH): Definition, Epidemiology and Etiology
Review literature: (Burnett und Wein, 2006) (DGU-Guideline: diagnostic work-up, 2009) (DGU-Guideline: treatment, 2009) (EAU-Guideline: Oelke et al, 2010)
Principles of Diagnostic Work-Up for BPH
The diagnostic challenge is to clarify the cause of the patient's micturition symptoms. Only after complete work-up and exclusion of other diseases, which cause micturition symptoms, the diagnosis BPH may be justified. The isolated interpretation of the symptoms of the patient, or of the maximum flow, or of the prostate volume is not sufficient to estimate the subvesical obstruction by the prostate. Fig. diagnostic work-up of LUTS summarizes European and American guidelines for diagnosis and treatment of LUTS due to benign prostatic hyperplasia.
Fig. diagnostic work-up of LUTS: algorithm for diagnosis and treatment of BPH at initial presentation, in accordance to the guidelines of the AUA 2003 [Kaplan, 2004a], DGU 2009 (DGU Guideline: diagnostic work-up, 2009) (DGU-guideline: treatment, 2009) and EAU 2010 (Oelke et al, 2010):
(*) Despite adequate medical therapy.
(**) Urodynamics should be considered in men under 50 years, in patients over 80 years, more than 300 ml residual urine, maximum urinary flow >15 ml/s, suspected neurogenic bladder dysfunction, after radical pelvic surgery, after unsuccessful non-invasive therapy.
(***) Not an option after urinary retention or hematuria.
The medical history is crucial for differential diagnosis of micturition symptoms:
Risk factors for urethral stricture:
Risk factors for urethral stricture are a history of urethritis, transurethral surgery, catheterization or perineal trauma.
Risk factors for neurogenic bladder disorders:
Diabetes mellitus, Parkinson's disease, stroke, spinal and pelvic surgery.
BPH symptoms may be aggravated by sympathomimetics, anticholinergics, antidepressants and antipsychotics.
A micturition diary is helpful in patients with nocturia to diagnose (nocturnal) polyuria caused by e.g. diabetes, COPD and heart failure.
Physical and prostate examination:
Quantification of BPH symptoms:
The IPSS questionnaire should be used for the quantification of complaints.
Laboratory Studies in BPH
Urine analysis can be done by microscopic examination of urine sediment or with urine test strips, in case of abnormalities a urine culture should be started.
Creatinine testing should be done to exclude postrenal kidney failure.
PSA testing helps to differentiate between BPH and prostate cancer. It is used in patients with a life expectancy of over 10 years. If the PSA concentration is greater than 4 ng/ml, a prostate biopsy should be considered. For a detailed discussion of PSA-based prostate cancer screening see section blood tests/PSA and prostate cancer.
BPH may also be responsible for elevated PSA concentrations. The PSA concentration correlates with the size of the prostate in symptomatic men and is prognostic for progression of BPH. In asymptomatic men, the PSA concentration does not have any prognostic significance for BPH.
Maximum Flow Rate:
For a meaningful uroflowmetry, the micturition volume should be >150 ml. A maximum flow rate below 10 ml/s is typical for symptomatic BPH, a maximum flow rate >15 ml/s should raise doubts for the diagnosis BPH which needs surgical treatment. Unfortunately, uroflowmetry contributes little to the differential diagnosis between subvesical obstruction versus bladder dysfunction.
Ultrasound Imaging in BPH:
- Postvoid residual urine? The significance of residual urine in the management of BPH patients is controversial. There are high intra-individual differences in residual urine. It is not proven, if residual urine is a cause of recurrent urinary tract infections. Most probable, residual urine correlates with detrusor weakness rather than with subvesical obstruction. Normal values or values to indicate surgery or to prognose failure of conservative therapy are lacking.
- Prostate size? Transabdominal ultrasound or transrectal ultrasound (TRUS) is used to measure prostate size. The prostate is measured in the sagittal plane (length) and horizontal plane (width and depth), the prostate volume is calculated using the formula:
V (prostate) = length × width × depth × 0.52
- Bladder pathology? Look for detrusor thickness, bladder stones or bladder diverticula.
Ultrasound imaging: bladder diverticulum. With kind permission of Prof. Dr. R. Harzmann, Augsburg.
Urodynamics in BPH:
Uroflowmetry is part of the basic diagnostic work-up. Further urodynamic testing (cystometry) is reserved for unclear cases, particularly before invasive therapy or after failure of medical treatment. Indications for cystometry are LUTS with a maximum flow rate >15 ml/s and suspected neurogenic bladder dysfunction without subvesical obstruction. Despite intensive urodynamic testing, there remains a proportion of almost 10% of patients, which have persisting complaints after surgical treatment for proven subvesical obstruction.
Cystoscopy is indicated for hematuria and to exclude urethral stricture, bladder stones, bladder diverticula or bladder cancer. Endoscopic features of BPH are a large median lobe, bladder bar, kissing lateral prostate lobes, bladder trabeculation and pseudodiverticula. The endoscopic picture cannot predict the need for surgical treatment [fig. cystoscopy of an obstructive prostate]. Cystoscopy should not be used for deciding whether an invasive therapy is necessary, but cystoscopy is helpful in planning surgical treatment (TURP or simple prostatectomy).
Fig. kissing lateral lobes in benign prostatic hyperplasia (BPH): cystoscopy (view from the colliculus seminalis in the direction bladder).
Radiological Imaging in BPH
IVU has long been standard for the evaluation of the upper urinary tract before surgical treatment in BPH. IVU reliably identifies hydronephrosis, bladder diverticula, residual urine and bladder stones [fig. intravenous urogram in BPH]. The intravenous contrast medium may cause serious complications in 0.1%. As an alternative, the combination of an abdominal x-ray, sonography of the kidneys and bladder and the serum concentration of creatinine concentration offers the same diagnostic power to detect complications from BPH without any side effects.
||Fig. intravenous urogram in BPH: the bladder floor is significantly raised by the enlargement of the prostate, the middle lobe is visible. The ureters show a fish-hook configuration before entering the bladder, hydronephrosis is not present. With kind permission of Dr. R. Gumpinger, Kempten.
Retrograde Urethrogram in BPH:
A retrograde urethrogram is indicated, if urethral stricture is suspected.
Cystography in BPH
Cystography is rare necessary to identify bladder diverticula or bladder stones [fig. cystography in BPH].
Fig. cystography in BPH showing multiple bladder diverticula: there is a bladder stone in the large right diverticulum, recognizable by the double contrast. With kind permission of Dr. R. Gumpinger, Kempten.
Index: 1–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Burnett und Wein 2006 BURNETT, A. L. ; WEIN,
- Benign prostatic hyperplasia in primary care: what you need to know.
In: J Urol
175 (2006), Nr. 3 Pt 2, S. S19–24
- DGU-Guidelines: diagnostic work-up
- Leitlinien der Deutschen Urologen zur Diagnostik des benignen
In: Urologe A
48 (2009), S. 1356–60, 1362–4
- DGU-Guidelines: treatment
- Leitlinien der Deutschen Urologen zur Therapie des benignen
In: Urologe A
48 (2009), S. 1503–1516
- Oelke, M.; Bachmann, A.; Descazeaud, A. & Emberton, M.
on conservative treatment of non-neurogenic male LUTS