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1、Benign Prostatic Hyperplasia,Background information,Benign prostatic hyperplasia (BPH) is a pathologic process that contributes to, but is not the sole cause of, lower urinary tract symptoms (LUTS) in aging men. Cause-and-effect relationships have not been established. A significant portion of LUTS
2、is due to age-related detrusor dysfunction.,Epidemiology and Natural History,Figure 1 Age-stratified autopsy prevalence of histologic BPH,Anatomy of the Prostate,Inferior to the bladder, contains the posterior urethra ( 2.5 cm in length). Support & Relations: Anterior: connected to the pubic symphys
3、is by the puboprostatic ligament. Inferior: urogenital diaphragm,Anatomy of the Prostate,Posterior: perforated by the ejaculatory ducts, separated from the rectum by 2 layers of Denonvilliers fascia and serosal rudiments of the pouch of Douglas.,Anatomy of the Prostate,Classification of Lowsley,5 lo
4、bes： Anterior Posterior Median Left lateral Right lateral,Classification of McNeal,Peripheral Zone: 70% (volume) Central Zone: 25% Transition Zone: 5% (BPH originates in) Normal size：46cm in cephalocaudad， 34cm at the base, 23cm in anteroposterior dimensions,Asian Prostate,The prostate volume of Asi
5、an males less than that of white people 4cm 3cm 2cm Different symptoms? Transition Zone Index = Vol of Transition Z. / total Vol of the prostate More transition zone! More BPH per prostate. Small prostate, serious symptoms!,Etiology,Not completely understood. The role of androgens and its receptors
6、Steroid 5-Reductase,Pathology,BPH develops in the transition zone. Its truly a hyperplastic process, resulting from an increase in cell number. A nodular growth pattern that is composed of varying amouts of stroma (collagen & smooth m.) and epithelium.,Pathology,Gross appearance of hyperplastic pros
7、tatic tissue obstructing the prostatic urethra forming “lobes.” A, Isolated middle lobe enlargement. B, Isolated lateral lobe enlargement. C, Lateral and middle lobe enlargement. D, Posterior commissural hyperplasia (median bar).,Components of BPH,Smooth muscle responsive to -blockers Epitheliumresp
8、onsive to 5-reductase inhibitors Collagen not respond,Pathophysiology,Complex interactions between urethral obstruction, detrusor function, and urine production. LUTS,Obstructive Component,Mechanical: Intrusion into the urethral lumen or bladder neck bladder outlet resistance Dynamic: prostatic stro
9、ma rich in adrenergic nerve supply a tone to the prostatic urethra (-blockers),The Bladders Response to Obstruction,Bladder outlet obstructiondetrusor m. hypertrophy & hyperplasia, collagen depositionthickened detrusor m. bundles seen as trabeculation diverticula formation,Trabeculation & Diverticul
10、a,Urinary retention,Can cause: Loss of anti-reflux function of ureteral orifices reflux kidney damage Stone formation & Infections,Diagnosis,Medical History Physical Examination Urinalysis Serum Creatinine Measurement Serum Prostate-Specific Antigen Uroflowmetry; Pressure-Flow studies Postvoid Resid
11、ual Urine Urethrocystoscopy Imaging of the Urinary Tract,Symptoms,1. Obstructive symptoms: Hesitancy, decreased forces & caliber of stream, sensation of incomplete bladder emptying, straining to urinate, post-void dribbling, etc. AUA (IPSS) Symptom Score Urinary retention (postvoid residual urine ),
12、Symptoms,2. Irritative symptoms: frequency, urgency, nocturia 3. Others: Hematuria, infections, stone formation, hydronephrosis, hernia or hemorrhoids,Stone formation,Physical Signs,DRE BPH results in a smooth firm elastic enlargement of the prostate. Induration, if detected, must alert the physicia
13、n the possibility of cancer.,Imagings,IVU: irregular border of the bladder, enlarged prostate can cause filling defect. Ultrasound: measure the prostatic volume & residual urine Vol = /6*W*L*H Weight (g)= /6*W*L*H*1.05,Other studies,Cystoscope: not recommended Urodynamic studies: suspected neurologi
14、c diseases or previous prostatic surgery failure,Differential Diagnosis,1. Bladder neck contracture & Urethral stricture: a history of previous urethral instrumentation, urithritis or trauma. Urethrography. 2. Prostate Cancer: induration on DRE, PSA, needle biopsy,Prostate Specific Antigen, 20 ng/ml
15、: Terror Zone? Not recommend any more,Differential Diagnosis,4. Bladder cancer: tumors at the bladder neck 5. Neurogenic bladder disorders: a history of neurologic diseases, stroke, DM or back injury. Urodynamic.,Treatment,Watchful Waiting Medical Therapy Surgery,Watchful Waiting,50% of symptomatic
16、men showed marked improvement or resolution of symptoms. 7% risk of developing urinary retention over 4 years.,Medical Therapy,-Receptor Blocker Long-acting: Terazosin, 2 mg QN po Tamsulosin (Harnal) , 0.20.4 mg QN po Selective blockade of the -1a receptors which are located in the prostate and bladder neck result in fewer systemic side effect (orthostatic hypotension, dizziness, rhinitis, tiredness & headache).,5-reductase inhibitor: Finasteride (Prosc
